Mesofluidic controlled robotic or prosthetic finger

DOEpatents

Lind, Randall F; Jansen, John F; Love, Lonnie J

2013-11-19

A mesofluidic powered robotic and/or prosthetic finger joint includes a first finger section having at least one mesofluidic actuator in fluid communication with a first actuator, a second mesofluidic actuator in fluid communication with a second actuator and a second prosthetic finger section pivotally connected to the first finger section by a joint pivot, wherein the first actuator pivotally cooperates with the second finger to provide a first mechanical advantage relative to the joint point and wherein the second actuator pivotally cooperates with the second finger section to provide a second mechanical advantage relative to the joint point.

Torque Control of Underactuated Tendon-driven Robotic Fingers

NASA Technical Reports Server (NTRS)

Ihrke, Chris A. (Inventor); Wampler, Charles W. (Inventor); Abdallah, Muhammad E. (Inventor); Reiland, Matthew J. (Inventor); Diftler, Myron A. (Inventor); Bridgwater, Lyndon (Inventor); Platt, Robert (Inventor)

2013-01-01

A robotic system includes a robot having a total number of degrees of freedom (DOF) equal to at least n, an underactuated tendon-driven finger driven by n tendons and n DOF, the finger having at least two joints, being characterized by an asymmetrical joint radius in one embodiment. A controller is in communication with the robot, and controls actuation of the tendon-driven finger using force control. Operating the finger with force control on the tendons, rather than position control, eliminates the unconstrained slack-space that would have otherwise existed. The controller may utilize the asymmetrical joint radii to independently command joint torques. A method of controlling the finger includes commanding either independent or parameterized joint torques to the controller to actuate the fingers via force control on the tendons.

Noninvasively measuring oxygen saturation of human finger-joint vessels by multi-transducer functional photoacoustic tomography

NASA Astrophysics Data System (ADS)

Deng, Zijian; Li, Changhui

2016-06-01

Imaging small blood vessels and measuring their functional information in finger joint are still challenges for clinical imaging modalities. In this study, we developed a multi-transducer functional photoacoustic tomography (PAT) system and successfully imaged human finger-joint vessels from ˜1 mm to <0.2 mm in diameter. In addition, the oxygen saturation (SO2) values of these vessels were also measured. Our results demonstrate that PAT can provide both anatomical and functional information of individual finger-joint vessels with different sizes, which might help the study of finger-joint diseases, such as rheumatoid arthritis.

Development of hand rehabilitation system for paralysis patient - universal design using wire-driven mechanism.

PubMed

Yamaura, Hiroshi; Matsushita, Kojiro; Kato, Ryu; Yokoi, Hiroshi

2009-01-01

We have developed a hand rehabilitation system for patients suffering from paralysis or contracture. It consists of two components: a hand rehabilitation machine, which moves human finger joints with motors, and a data glove, which provides control of the movement of finger joints attached to the rehabilitation machine. The machine is based on the arm structure type of hand rehabilitation machine; a motor indirectly moves a finger joint via a closed four-link mechanism. We employ a wire-driven mechanism and develop a compact design that can control all three joints (i.e., PIP, DIP and MP ) of a finger and that offers a wider range of joint motion than conventional systems. Furthermore, we demonstrate the hand rehabilitation process, finger joints of the left hand attached to the machine are controlled by the finger joints of the right hand wearing the data glove.

Kinematic evaluation of the finger's interphalangeal joints coupling mechanism--variability, flexion-extension differences, triggers, locking swanneck deformities, anthropometric correlations.

PubMed

Leijnse, J N A L; Quesada, P M; Spoor, C W

2010-08-26

The human finger contains tendon/ligament mechanisms essential for proper control. One mechanism couples the movements of the interphalangeal joints when the (unloaded) finger is flexed with active deep flexor. This study's aim was to accurately determine in a large finger sample the kinematics and variability of the coupled interphalangeal joint motions, for potential clinical and finger model validation applications. The data could also be applied to humanoid robotic hands. Sixty-eight fingers were measured in seventeen hands in nine subjects. Fingers exhibited great joint mobility variability, with passive proximal interphalangeal hyperextension ranging from zero to almost fifty degrees. Increased measurement accuracy was obtained by using marker frames to amplify finger segment motions. Gravitational forces on the marker frames were not found to invalidate measurements. The recorded interphalangeal joint trajectories were highly consistent, demonstrating the underlying coupling mechanism. The increased accuracy and large sample size allowed for evaluation of detailed trajectory variability, systematic differences between flexion and extension trajectories, and three trigger types, distinct from flexor tendon triggers, involving initial flexion deficits in either proximal or distal interphalangeal joint. The experimental methods, data and analysis should advance insight into normal and pathological finger biomechanics (e.g., swanneck deformities), and could help improve clinical differential diagnostics of trigger finger causes. The marker frame measuring method may be useful to quantify interphalangeal joints trajectories in surgical/rehabilitative outcome studies. The data as a whole provide the most comprehensive collection of interphalangeal joint trajectories for clinical reference and model validation known to us to date. 2010 Elsevier Ltd. All rights reserved.

Multi-scale recordings for neuroprosthetic control of finger movements.

PubMed

Baker, Justin; Bishop, William; Kellis, Spencer; Levy, Todd; House, Paul; Greger, Bradley

2009-01-01

We trained a rhesus monkey to perform individuated and combined finger flexions and extensions of the thumb, index, and middle finger. A Utah Electrode Array (UEA) was implanted into the hand region of the motor cortex contralateral to the monkey's trained hand. We also implanted a microwire electrocorticography grid (microECoG) epidurally so that it covered the UEA. The microECoG grid spanned the arm and hand regions of both the primary motor and somatosensory cortices. Previously this monkey had Implantable MyoElectric Sensors (IMES) surgically implanted into the finger muscles of the monkey's forearm. Action potentials (APs), local field potentials (LFPs), and microECoG signals were recorded from wired head-stage connectors for the UEA and microECoG grids, while EMG was recorded wirelessly. The monkey performed a finger flexion/extension task while neural and EMG data were acquired. We wrote an algorithm that uses the spike data from the UEA to perform a real-time decode of the monkey's finger movements. Also, analyses of the LFP and microECoG data indicate that these data show trial-averaged differences between different finger movements, indicating the data are potentially decodeable.

Bioinspired Robotic Fingers Based on Pneumatic Actuator and 3D Printing of Smart Material.

PubMed

Yang, Yang; Chen, Yonghua; Li, Yingtian; Chen, Michael Z Q; Wei, Ying

2017-06-01

In this article, we have proposed a novel robotic finger design principle aimed to address two challenges in soft pneumatic grippers-the controllability of the stiffness and the controllability of the bending position. The proposed finger design is composed of a 3D printed multimaterial substrate and a soft pneumatic actuator. The substrate has four polylactic acid (PLA) segments interlocked with three shape memory polymer (SMP) joints, inspired by bones and joints in human fingers. By controlling the thermal energy of an SMP joint, the stiffness of the joints is modulated due to the dramatic change in SMP elastic modulus around its glass transition temperature (T g ). When SMP joints are heated above T g , they exhibit very small stiffness, allowing the finger to easily bend around the SMP joints if the attached soft actuator is actuated. When there is no force from the soft actuator, shape recovery stress in SMP contributes to the finger's shape restoration. Since each joint's rotation can be individually controlled, the position control of the finger is made possible. Experimental analysis has been conducted to show the finger's variable stiffness and the result is compared with the analytical values. It is found that the stiffness ratio can be 24.9 times for a joint at room temperature (20°C) and at an elevated temperature of 60°C when air pressure p of the soft actuator is turned off. Finally, a gripper composed of two fingers is fabricated for demonstration.

Prevalence of sesamoid bones in the interphalangeal joint of the thumb and fingers: a radiographic study.

PubMed

Seki, Yasuhiro; Hoshino, Yuko; Kuroda, Hiroshi

2013-10-01

The prevalence of sesamoid bones in the hands has been reported in some previous articles. Most of them, however, have reported sesamoid bones of the metacarpophalangeal joint of the hand and of the interphalangeal (IP) joint of the thumb. The present study investigates the prevalence of sesamoid bones of the IP joint of the thumb and fingers. A retrospective review of radiologic views of the IP joints in the thumb or fingers was performed, including a total of 650 patients (1,096 thumbs or fingers). Sesamoid bones were found in the IP joint of the thumb at 67% (212 of 318), while the index, middle, ring, little fingers had sesamoid bones in the proximal interphlangeal (PIP) joint at 0% (0 of 172), 0.4% (1 of 244), 0.5% (1 of 183), and 1% (2 of 179), respectively. None of the four fingers had sesamoid bones in the distal IP joint. Previous articles have described the similar prevalence to the present study, of sesamoid bones of the IP joint of the thumb, while some others reported the different prevalence. About the PIP joint, no previous articles have found a sesamoid bone. Because the lateral X-ray view is more accurate and suitable to evaluate sesamoid bones, we used the lateral one for the present study. The knowledge that sesamoid bones occurs at these rates in the thumb IP joint and finger PIP joints is helpful to differentiate chip fractures from sesamoid bones near the IP joint, including the PIP joint. Copyright © 2012 Wiley Periodicals, Inc.

Hand kinematics of piano playing

PubMed Central

Flanders, Martha; Soechting, John F.

2011-01-01

Dexterous use of the hand represents a sophisticated sensorimotor function. In behaviors such as playing the piano, it can involve strong temporal and spatial constraints. The purpose of this study was to determine fundamental patterns of covariation of motion across joints and digits of the human hand. Joint motion was recorded while 5 expert pianists played 30 excerpts from musical pieces, which featured ∼50 different tone sequences and fingering. Principal component analysis and cluster analysis using an expectation-maximization algorithm revealed that joint velocities could be categorized into several patterns, which help to simplify the description of the movements of the multiple degrees of freedom of the hand. For the thumb keystroke, two distinct patterns of joint movement covariation emerged and they depended on the spatiotemporal patterns of the task. For example, the thumb-under maneuver was clearly separated into two clusters based on the direction of hand translation along the keyboard. While the pattern of the thumb joint velocities differed between these clusters, the motions at the metacarpo-phalangeal and proximal-phalangeal joints of the four fingers were more consistent. For a keystroke executed with one of the fingers, there were three distinct patterns of joint rotations, across which motion at the striking finger was fairly consistent, but motion of the other fingers was more variable. Furthermore, the amount of movement spillover of the striking finger to the adjacent fingers was small irrespective of the finger used for the keystroke. These findings describe an unparalleled amount of independent motion of the fingers. PMID:21880938

Modeling the finger joint moments in a hand at the maximal isometric grip: the effects of friction.

PubMed

Wu, John Z; Dong, Ren G; McDowell, Thomas W; Welcome, Daniel E

2009-12-01

The interaction between the handle and operator's hand affects the comfort and safety of tool and machine operations. In most of the previous studies, the investigators considered only the normal contact forces. The effect of friction on the joint moments in fingers has not been analyzed. Furthermore, the observed contact forces have not been linked to the internal musculoskeletal loading in the previous experimental studies. In the current study, we proposed a universal model of a hand to evaluate the joint moments in the fingers during grasping tasks. The hand model was developed on the platform of the commercial software package AnyBody. Only four fingers (index, long, ring, and little finger) were included in the model. The anatomical structure of each finger is comprised of four phalanges (distal, middle, proximal, and metacarpal phalange). The simulations were performed using an inverse dynamics technique. The joint angles and the normal contact forces on each finger section reported by previous researchers were used as inputs, while the joint moments of each finger were predicted. The predicted trends of the dependence of the distal interphalangeal (DIP) and proximal interphalangeal (PIP) joint moments on the cylinder diameter agree with those of the contact forces on the fingers observed in the previous experimental study. Our results show that the DIP and PIP joint moments reach their maximums at a cylinder diameter of about 31mm, which is consistent with the trend of the finger contact forces measured in the experiments. The proposed approach will be useful for simulating musculoskeletal loading in the hand for occupational activities, thereby optimizing tool-handle design.

Measurement of clinicians' ability to hand torque dental implant components.

PubMed

Kanawati, Ali; Richards, Mark W; Becker, Jeffery J; Monaco, Natalie E

2009-01-01

There is a varying degree of hand torque abilities using finger drivers among clinicians. Calibrating one's own abilities requires complicated instruments not readily available. This study evaluated a simple-to-use method that allows dental practitioners to have a quantifiable clinical assessment of relative torque ability using finger drivers to torque down dental implant components. A typodont that includes dental implants was mounted in a mannequin placed in a patient-reclined position. The subjects were asked to torque as tightly as they could a new healing abutment to an implant secured firmly in resin within the typodont. All participants wore moistened gloves when using a finger driver. The healing abutment was countertorqued using a certified precalibrated precision torque measurement device. The reading on the torque driver was recorded when the healing abutment disengaged. An average of torque values of dentists and dental students was calculated. Fifty subjects had an average maximum torque ability of 24 Ncm (male dentists: 28 Ncm; students: 22 Ncm; male students: 24 Ncm; female students: 19 Ncm). Maximum torque values for all participants ranged from 11 Ncm to 38 Ncm. There was no significant difference between groups. This study showed a varying degree of hand torquing abilities using a finger driver. Clinicians should regularly calibrate their ability to torque implant components to more predictably perform implant dentistry. Dental implant manufacturers should more precisely instruct clinicians as to maximum torque, as opposed to "finger tighten only".

Continuous detection and decoding of dexterous finger flexions with implantable myoelectric sensors.

PubMed

Baker, Justin J; Scheme, Erik; Englehart, Kevin; Hutchinson, Douglas T; Greger, Bradley

2010-08-01

A rhesus monkey was trained to perform individuated and combined finger flexions of the thumb, index, and middle finger. Nine implantable myoelectric sensors (IMES) were then surgically implanted into the finger muscles of the monkey's forearm, without any adverse effects over two years postimplantation. Using an inductive link, EMG was wirelessly recorded from the IMES as the monkey performed a finger flexion task. The EMG from the different IMES implants showed very little cross correlation. An offline parallel linear discriminant analysis (LDA) based algorithm was used to decode finger activity based on features extracted from continuously presented frames of recorded EMG. The offline parallel LDA was run on intraday sessions as well as on sessions where the algorithm was trained on one day and tested on following days. The performance of the algorithm was evaluated continuously by comparing classification output by the algorithm to the current state of the finger switches. The algorithm detected and classified seven different finger movements, including individual and combined finger flexions, and a no-movement state (chance performance = 12.5%) . When the algorithm was trained and tested on data collected the same day, the average performance was 43.8+/-3.6% n=10. When the training-testing separation period was five months, the average performance of the algorithm was 46.5+/-3.4% n=8. These results demonstrated that using EMG recorded and wirelessly transmitted by IMES offers a promising approach for providing intuitive, dexterous control of artificial limbs where human patients have sufficient, functional residual muscle following amputation.

21 CFR 888.3210 - Finger joint metal/metal constrained cemented prosthesis.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Finger joint metal/metal constrained cemented prosthesis. 888.3210 Section 888.3210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3210 Finger joint...

21 CFR 888.3210 - Finger joint metal/metal constrained cemented prosthesis.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Finger joint metal/metal constrained cemented prosthesis. 888.3210 Section 888.3210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3210 Finger joint...

21 CFR 888.3200 - Finger joint metal/metal constrained uncemented prosthesis.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Finger joint metal/metal constrained uncemented prosthesis. 888.3200 Section 888.3200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3200 Finger joint...

21 CFR 888.3210 - Finger joint metal/metal constrained cemented prosthesis.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Finger joint metal/metal constrained cemented prosthesis. 888.3210 Section 888.3210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3210 Finger joint...

21 CFR 888.3200 - Finger joint metal/metal constrained uncemented prosthesis.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Finger joint metal/metal constrained uncemented prosthesis. 888.3200 Section 888.3200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3200 Finger joint...

21 CFR 888.3200 - Finger joint metal/metal constrained uncemented prosthesis.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Finger joint metal/metal constrained uncemented prosthesis. 888.3200 Section 888.3200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3200 Finger joint...

Involuntary Neuromuscular Coupling between the Thumb and Finger of Stroke Survivors during Dynamic Movement.

PubMed

Jones, Christopher L; Kamper, Derek G

2018-01-01

Finger-thumb coordination is crucial to manual dexterity but remains incompletely understood, particularly following neurological injury such as stroke. While being controlled independently, the index finger and thumb especially must work in concert to perform a variety of tasks requiring lateral or palmar pinch. The impact of stroke on this functionally critical sensorimotor control during dynamic tasks has been largely unexplored. In this study, we explored finger-thumb coupling during close-open pinching motions in stroke survivors with chronic hemiparesis. Two types of perturbations were applied randomly to the index with a novel Cable-Actuated Finger Exoskeleton: a sudden joint acceleration stretching muscle groups of the index finger and a sudden increase in impedance in selected index finger joint(s). Electromyographic signals for specific thumb and index finger muscles, thumb tip trajectory, and index finger joint angles were recorded during each trial. Joint angle perturbations invoked reflex responses in the flexor digitorum superficialis (FDS), first dorsal interossei (FDI), and extensor digitorum communis muscles of the index finger and heteronymous reflex responses in flexor pollicis brevis of the thumb ( p  < 0.017). Phase of movement played a role as a faster peak reflex response was observed in FDI during opening than during closing ( p  < 0.002) and direction of perturbations resulted in shorter reflex times for FDS and FDI ( p  < 0.012) for extension perturbations. Surprisingly, when index finger joint impedance was suddenly increased, thumb tip movement was substantially increased, from 2 to 10 cm ( p  < 0.001). A greater effect was seen during the opening phase ( p  < 0.044). Thus, involuntary finger-thumb coupling was present during dynamic movement, with perturbation of the index finger impacting thumb activity. The degree of coupling modulated with the phase of motion. These findings reveal a potential mechanism for direct intervention to improve poststroke hand mobility and provide insight on prospective neurologically oriented therapies.

Arthrodesis of the thumb interphalangeal joint and finger distal interphalangeal joints with a headless compression screw.

PubMed

Cox, Christopher; Earp, Brandon E; Floyd, W Emerson; Blazar, Philip E

2014-01-01

To study the results of using a small, headless compression screw (AcuTwist) for thumb interphalangeal (IP) joint and finger distal interphalangeal (DIP) joint arthrodeses. Between November 2007 and January 2012, 48 primary arthrodeses of the thumb IP joint or DIP joint in the other digits were performed in 29 consecutive patients with AcuTwist devices. Indications for arthrodesis included 19 cases of osteoarthritis in 25 fingers, 3 cases of lupus in 9 fingers, 2 cases of post-traumatic osteoarthritis in 2 fingers, and 1 case and finger each of acute trauma, neuromuscular disorder, postinfectious osteoarthritis, boutonniere deformity, and Dupuytren contracture. Charts were reviewed for clinical data, and radiographs were assessed for alignment and healing. Age averaged 59 years and follow-up averaged 12 months (range, 2-50 mo). Union occurred in 43 out of 46 fingers (94%). There were no cases of nail deformity, wound complications, tip hypersensitivity, or clinically notable malalignment. Three arthrodeses failed to fuse, including 2 asymptomatic nonunions and 1 fixation loss requiring revision with autograft. The complication rate was 9%. Distal digital joint arthrodesis with the AcuTwist resulted in a fusion rate of 94% with a complication rate of 9%. Our rate of fusion compares favorably with prior series using other methods of fixation. Therapeutic IV. Copyright © 2014 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Change in the temporal coordination of the finger joints with ulnar nerve block during different power grips analyzed with a sensor glove.

PubMed

Wachter, N J; Mentzel, M; Häderer, C; Krischak, G D; Gülke, J

2018-02-01

Ulnar nerve injuries can cause deficient hand movement patterns. Their assessment is important for diagnosis and rehabilitation in hand surgery cases. The purpose of this study was to quantify the changes in temporal coordination of the finger joints during different power grips with an ulnar nerve block by means of a sensor glove. In 21 healthy subjects, the onset and end of the active flexion of the 14 finger joints when gripping objects of different diameters was recorded by a sensor glove. The measurement was repeated after an ulnar nerve block was applied in a standardized setting. The change in the temporal coordination of the metacarpophalangeal (MCP), proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints with and without the nerve block was calculated within the same subject. In healthy subjects, the MCP joints started their movement prior to the PIP joints in the middle and ring finger, whereas this occurred in the reverse order at the index and little finger. The DIP joint onset was significantly delayed (P<0.01). With the ulnar nerve block, this coordination shifted towards simultaneous onset of all joints, independent of the grip diameter. The thumb and index finger were affected the least. With an ulnar nerve block, the PIP joints completed their movement prior to the MCP joints when gripping small objects (G1 and G2), whereas the order was reversed with larger objects (G3 and G4). The alterations with ulnar nerve block affected mainly the little finger when gripping small objects. With larger diameter objects, all fingers had a significant delay at the end of the PIP joint movement relative to the MCP and DIP joints, and the PIP and DIP joint sequence was reversed (P<0.01). Based on the significant changes in temporal coordination of finger flexion during different power grips, there are biomechanical effects of loss of function of the intrinsic muscles caused by an ulnar nerve block on the fine motor skills of the hand. This can be important for the diagnosis and rehabilitation of ulnar nerve lesions of the hand. Copyright © 2017 SFCM. Published by Elsevier Masson SAS. All rights reserved.

Temporal Control and Hand Movement Efficiency in Skilled Music Performance

PubMed Central

Goebl, Werner; Palmer, Caroline

2013-01-01

Skilled piano performance requires considerable movement control to accomplish the high levels of timing and force precision common among professional musicians, who acquire piano technique over decades of practice. Finger movement efficiency in particular is an important factor when pianists perform at very fast tempi. We document the finger movement kinematics of highly skilled pianists as they performed a five-finger melody at very fast tempi. A three-dimensional motion-capture system tracked the movements of finger joints, the hand, and the forearm of twelve pianists who performed on a digital piano at successively faster tempi (7–16 tones/s) until they decided to stop. Joint angle trajectories computed for all adjacent finger phalanges, the hand, and the forearm (wrist angle) indicated that the metacarpophalangeal joint contributed most to the vertical fingertip motion while the proximal and distal interphalangeal joints moved slightly opposite to the movement goal (finger extension). An efficiency measure of the combined finger joint angles corresponded to the temporal accuracy and precision of the pianists’ performances: Pianists with more efficient keystroke movements showed higher precision in timing and force measures. Keystroke efficiency and individual joint contributions remained stable across tempo conditions. Individual differences among pianists supported the view that keystroke efficiency is required for successful fast performance. PMID:23300946

Modeling of the interaction between grip force and vibration transmissibility of a finger.

PubMed

Wu, John Z; Welcome, Daniel E; McDowell, Thomas W; Xu, Xueyan S; Dong, Ren G

2017-07-01

It is known that the vibration characteristics of the fingers and hand and the level of grip action interacts when operating a power tool. In the current study, we developed a hybrid finger model to simulate the vibrations of the hand-finger system when gripping a vibrating handle covered with soft materials. The hybrid finger model combines the characteristics of conventional finite element (FE) models, multi-body musculoskeletal models, and lumped mass models. The distal, middle, and proximal finger segments were constructed using FE models, the finger segments were connected via three flexible joint linkages (i.e., distal interphalangeal joint (DIP), proximal interphalangeal joint (PIP), and metacarpophalangeal (MCP) joint), and the MCP joint was connected to the ground and handle via lumped parameter elements. The effects of the active muscle forces were accounted for via the joint moments. The bone, nail, and hard connective tissues were assumed to be linearly elastic whereas the soft tissues, which include the skin and subcutaneous tissues, were considered as hyperelastic and viscoelastic. The general trends of the model predictions agree well with the previous experimental measurements in that the resonant frequency increased from proximal to the middle and to the distal finger segments for the same grip force, that the resonant frequency tends to increase with increasing grip force for the same finger segment, especially for the distal segment, and that the magnitude of vibration transmissibility tends to increase with increasing grip force, especially for the proximal segment. The advantage of the proposed model over the traditional vibration models is that it can predict the local vibration behavior of the finger to a tissue level, while taking into account the effects of the active musculoskeletal force, the effects of the contact conditions on vibrations, the global vibration characteristics. Published by Elsevier Ltd.

Finger jointing green southern yellow pine with a soy-based adhesive

Treesearch

Philip H. Steele; Roland E. Kreibicha; Petrus J. Steynberg; Richard W. Hemingway

1998-01-01

The authors present results of laboratory tests for a soy-based adhesive to bond southern yellow pine using the finger-jointing method. There was some reason to suspect that finger jointing of southern yellow pine (SYP) with the honeymoon system using soy-based adhesive might prove more difficult than for western species. The Wood Handbook classes western species in...

Comparison of dominant hand range of motion among throwing types in baseball pitchers.

PubMed

Wang, Lin-Hwa; Kuo, Li-Chieh; Shih, Sheng-Wen; Lo, Kuo-Cheng; Su, Fong-Chin

2013-08-01

Previous research on baseball pitchers' wrists, elbows, and should joints contributes to our understanding of pitchers' control over delicate joint motion and ball release. However, limited research on forearm, wrist, and hand joints prevents full comprehension of the throwing mechanism. The present descriptive laboratory study quantifies angular performances of hand and wrist joints while pitching breaking balls, including fastballs, curveballs and sliders, among pitchers with different skill levels. Nineteen baseball pitchers performed required pitching tasks (10 from university and 9 from high school). A three-dimensional motion analysis system collected pitching motion data. The range of joint motion in the wrist and proximal interphalangeal (PIP) and metacarpophalangeal (MP) joints of the index and middle fingers were compared among fastballs, curveballs and sliders. Thirteen reflective markers were placed on selected anatomic landmarks of the wrist, middle and index fingers of the hand. Wrist flexion angle in the pitching acceleration phase was larger in fastballs (20.58±4.07°) and sliders (22.48±5.45°) than in curveballs (9.08±3.03°) (p = .001). The flexion angle of the PIP joint was significantly larger in curveballs (38.5±3.8°) than in fastballs (30.3±4.8°) and sliders (30.2±4.5°) (p=.004) of the middle finger. Abduction angle of MP joint on the middle finger was significantly larger in curveballs (15.4 ±3.6°) than in fastballs (8.9±1.2°) and sliders (6.9±2.9°) (p=.001) of the middle finger, and the abduction angle of index finger was significantly larger in sliders (13.5±15.0°) than in fastballs (7.2 ±2.8°) (p=.007). Hand and wrist motion and grip types affect the relative position between fingers and ball, which produces different types of baseball pitches. A larger extension angle of the wrist joint and the coordination of middle and index fingers are crucial when pitching a fastball. Abduction and flexion movement on the MP joint of the middle finger are important for a curveball. MP joint abduction and flexion movement of the index finger produce sliders. Understanding the control mechanism in a throwing hand can help improve training protocols in either injury prevention or performance improvement for baseball pitchers. Copyright © 2013 Elsevier B.V. All rights reserved.

[Second toe transfer in congenital hand differences].

PubMed

Dautel, G; Barbary, S

2008-12-01

In congenital hand differences, microsurgical toe transfer involves the creation of one or several rays in a child that never possessed them before. Second toe transplantation was uniformly used in this series that include 65 consecutive cases. Etiologies were represented by symbrachydactyly, constriction band syndrome or central cleft hand. Second toe transfer was performed with or without the MTP joint and followed by proximal ray resection of the donor toe. In the vast majority of theses cases, transplantation was performed in adactylic or monodactylic hand, the ultimate functional goal was the creation of a "tip-to-tip" two fingers pinch. Implantation site was chosen according to the situation of the existing finger(s). The existence of a functioning recipient MCP joint was one of the key factors of the final functional outcome. There were two vascular failures in this series with complete necrosis of the transplanted toe. Two additional toes appeared mediocre with respect to the overall transfer integration. The final mobility of the fingers reconstructed was measured using the total active motion score. Average TAM was poor (42 degrees +/-24 degrees ). In 12 out of 15 patients that were evaluated with a follow-up of at least five years, the static two-point discrimination was found to be excellent (less than 6mm). Our series did not allow us to establish a firm correlation between the type of nerve suture used and the quality of sensory recovery. Growth was measured as a percentage of the intact second toe (68 to 95%). All children on a long term basis had a normal gait without any impediment during sports or leisure activities. Clinical results obtained in this series lead to think that the cerebral cortex has got some plasticity which allows the integration of the transplants.

Management of the Stiff Finger: Evidence and Outcomes

PubMed Central

Yang, Guang; McGlinn, Evan P.; Chung, Kevin C.

2014-01-01

SYNOPSIS The term “stiff finger” refers to a reduction in the range of motion in the finger, and it is a condition that has many different causes and involves a number of different structures. Almost all injuries of the fingers and some diseases can cause finger stiffness. Hand surgeons often face difficulty treating stiff fingers that are affected by irreversible soft tissues fibrosis. Stiff fingers can be divided into flexion and extension deformities. They can also be sub-classified into four categories according to the involved tissues extending from the skin to the joint capsule. Prevention of stiff fingers by judicious mobilization of the joints is prudent to avoid more complicated treatment after established stiffness occurs. Static progressive and dynamic splints have been considered as effective non-operative interventions to treat stiff fingers. Most authors believe force of joint distraction and time duration of stretching are two important factors to consider while applying a splint or cast. We also introduce the concepts of capsulotomy and collateral ligament release and other soft tissue release of the MCP and PIP joint in this article. Future outcomes research is vital to assessing the effectiveness of these surgical procedures and guiding postoperative treatment recommendations. PMID:24996467

Extrinsic versus intrinsic hand muscle dominance in finger flexion.

PubMed

Al-Sukaini, A; Singh, H P; Dias, J J

2016-05-01

This study aims to identify the patterns of dominance of extrinsic or intrinsic muscles in finger flexion during initiation of finger curl and mid-finger flexion. We recorded 82 hands of healthy individuals (18-74 years) while flexing their fingers and tracked the finger joint angles of the little finger using video motion tracking. A total of 57 hands (69.5%) were classified as extrinsic dominant, where the finger flexion was initiated and maintained at proximal interphalangeal and distal interphalangeal joints. A total of 25 (30.5%) were classified as intrinsic dominant, where the finger flexion was initiated and maintained at the metacarpophalangeal joint. The distribution of age, sex, dominance, handedness and body mass index was similar in the two groups. This knowledge may allow clinicians to develop more efficient rehabilitation regimes, since intrinsic dominant individuals would not initiate extrinsic muscle contraction till later in finger flexion, and might therefore be allowed limited early active motion. For extrinsic dominant individuals, by contrast, initial contraction of extrinsic muscles would place increased stress on the tendon repair site if early motion were permitted. © The Author(s) 2016.

Design of a Reconfigurable Robotic System for Flexoextension Fitted to Hand Fingers Size

PubMed Central

Castillo-Castaneda, Eduardo

2016-01-01

Due to the growing demand for assistance in rehabilitation therapies for hand movements, a robotic system is proposed to mobilize the hand fingers in flexion and extension exercises. The robotic system is composed by four, type slider-crank, mechanisms that have the ability to fit the user fingers length from the index to the little finger, through the adjustment of only one link for each mechanism. The trajectory developed by each mechanism corresponds to the natural flexoextension path of each finger. The amplitude of the rotations for metacarpophalangeal joint (MCP) and proximal interphalangeal joint (PIP) varies from 0 to 90° and the distal interphalangeal joint (DIP) varies from 0 to 60°; the joint rotations are coordinated naturally. The four R-RRT mechanisms orientation allows a 15° abduction movement for index, ring, and little fingers. The kinematic analysis of this mechanism was developed in order to assure that the displacement speed and smooth acceleration into the desired range of motion and the simulation results are presented. The reconfiguration of mechanisms covers about 95% of hand sizes of a group of Mexican adult population. Maximum trajectory tracking error is less than 3% in full range of movement and it can be compensated by the additional rotation of finger joints without injury to the user. PMID:27524880

Design of a Reconfigurable Robotic System for Flexoextension Fitted to Hand Fingers Size.

PubMed

Aguilar-Pereyra, J Felipe; Castillo-Castaneda, Eduardo

2016-01-01

Due to the growing demand for assistance in rehabilitation therapies for hand movements, a robotic system is proposed to mobilize the hand fingers in flexion and extension exercises. The robotic system is composed by four, type slider-crank, mechanisms that have the ability to fit the user fingers length from the index to the little finger, through the adjustment of only one link for each mechanism. The trajectory developed by each mechanism corresponds to the natural flexoextension path of each finger. The amplitude of the rotations for metacarpophalangeal joint (MCP) and proximal interphalangeal joint (PIP) varies from 0 to 90° and the distal interphalangeal joint (DIP) varies from 0 to 60°; the joint rotations are coordinated naturally. The four R-RRT mechanisms orientation allows a 15° abduction movement for index, ring, and little fingers. The kinematic analysis of this mechanism was developed in order to assure that the displacement speed and smooth acceleration into the desired range of motion and the simulation results are presented. The reconfiguration of mechanisms covers about 95% of hand sizes of a group of Mexican adult population. Maximum trajectory tracking error is less than 3% in full range of movement and it can be compensated by the additional rotation of finger joints without injury to the user.

Ability of finger-jointed lumber to maintain load at elevated temperatures

Treesearch

Douglas R. Rammer; Samuel L. Zelinka; Laura E Hasburgh; Steven T. Craft

2018-01-01

This article presents a test method that was developed to screen adhesive formulations for finger-jointed lumber. The goal was to develop a small-scale test that could be used to predict whether an adhesive would pass a full-scale ASTM E119 wall assembly test. The method involved loading a 38-mm square finger-jointed sample in a four-point bending test inside of an...

Finger-Jointed Wood Products.

DTIC Science & Technology

1981-04-01

these melamines do not have the same Urea resins are generally marketed adhesives does not always develop resistance to weathering as do in liquid form...OF durable, colorless glueline is required. been developed for use in RF curing. FINGER JOINTS MelamineUrea Resins IN STRUCTURAL Melamine - urea resins ...finger duced either by dry blending urea and moplastic, softening if temperature is joints, strength is expressed as a melamine resins or by blending

Involuntary Neuromuscular Coupling between the Thumb and Finger of Stroke Survivors during Dynamic Movement

PubMed Central

Jones, Christopher L.; Kamper, Derek G.

2018-01-01

Finger–thumb coordination is crucial to manual dexterity but remains incompletely understood, particularly following neurological injury such as stroke. While being controlled independently, the index finger and thumb especially must work in concert to perform a variety of tasks requiring lateral or palmar pinch. The impact of stroke on this functionally critical sensorimotor control during dynamic tasks has been largely unexplored. In this study, we explored finger–thumb coupling during close–open pinching motions in stroke survivors with chronic hemiparesis. Two types of perturbations were applied randomly to the index with a novel Cable-Actuated Finger Exoskeleton: a sudden joint acceleration stretching muscle groups of the index finger and a sudden increase in impedance in selected index finger joint(s). Electromyographic signals for specific thumb and index finger muscles, thumb tip trajectory, and index finger joint angles were recorded during each trial. Joint angle perturbations invoked reflex responses in the flexor digitorum superficialis (FDS), first dorsal interossei (FDI), and extensor digitorum communis muscles of the index finger and heteronymous reflex responses in flexor pollicis brevis of the thumb (p < 0.017). Phase of movement played a role as a faster peak reflex response was observed in FDI during opening than during closing (p < 0.002) and direction of perturbations resulted in shorter reflex times for FDS and FDI (p < 0.012) for extension perturbations. Surprisingly, when index finger joint impedance was suddenly increased, thumb tip movement was substantially increased, from 2 to 10 cm (p < 0.001). A greater effect was seen during the opening phase (p < 0.044). Thus, involuntary finger–thumb coupling was present during dynamic movement, with perturbation of the index finger impacting thumb activity. The degree of coupling modulated with the phase of motion. These findings reveal a potential mechanism for direct intervention to improve poststroke hand mobility and provide insight on prospective neurologically oriented therapies. PMID:29545767

Multi-fingered robotic hand

NASA Technical Reports Server (NTRS)

Ruoff, Carl F. (Inventor); Salisbury, Kenneth, Jr. (Inventor)

1990-01-01

A robotic hand is presented having a plurality of fingers, each having a plurality of joints pivotally connected one to the other. Actuators are connected at one end to an actuating and control mechanism mounted remotely from the hand and at the other end to the joints of the fingers for manipulating the fingers and passing externally of the robot manipulating arm in between the hand and the actuating and control mechanism. The fingers include pulleys to route the actuators within the fingers. Cable tension sensing structure mounted on a portion of the hand are disclosed, as is covering of the tip of each finger with a resilient and pliable friction enhancing surface.

Coordinated turn-and-reach movements. II. Planning in an external frame of reference

NASA Technical Reports Server (NTRS)

Pigeon, Pascale; Bortolami, Simone B.; DiZio, Paul; Lackner, James R.

2003-01-01

The preceding study demonstrated that normal subjects compensate for the additional interaction torques generated when a reaching movement is made during voluntary trunk rotation. The present paper assesses the influence of trunk rotation on finger trajectories and on interjoint coordination and determines whether simultaneous turn-and-reach movements are most simply described relative to a trunk-based or an external reference frame. Subjects reached to targets requiring different extents of arm joint and trunk rotation at a natural pace and quickly in normal lighting and in total darkness. We first examined whether the larger interaction torques generated during rapid turn-and-reach movements perturb finger trajectories and interjoint coordination and whether visual feedback plays a role in compensating for these torques. These issues were addressed using generalized Procrustes analysis (GPA), which attempts to overlap a group of configurations (e.g., joint trajectories) through translations and rotations in multi-dimensional space. We first used GPA to identify the mean intrinsic patterns of finger and joint trajectories (i.e., their average shape irrespective of location and orientation variability in the external and joint workspaces) from turn-and-reach movements performed in each experimental condition and then calculated their curvatures. We then quantified the discrepancy between each finger or joint trajectory and the intrinsic pattern both after GPA was applied individually to trajectories from a pair of experimental conditions and after GPA was applied to the same trajectories pooled together. For several subjects, joint trajectories but not finger trajectories were more curved in fast than slow movements. The curvature of both joint and finger trajectories of turn-and-reach movements was relatively unaffected by the vision conditions. Pooling across speed conditions significantly increased the discrepancy between joint but not finger trajectories for most subjects, indicating that subjects used different patterns of interjoint coordination in slow and fast movements while nevertheless preserving the shape of their finger trajectory. Higher movement speeds did not disrupt the arm joint rotations despite the larger interaction torques generated. Rather, subjects used the redundant degrees of freedom of the arm/trunk system to achieve similar finger trajectories with differing joint configurations. We examined finger movement patterns and velocity profiles to determine the frame of reference in which turn-and-reach movements could be most simply described. Finger trajectories of turn-and-reach movements had much larger curvatures and their velocity profiles were less smooth and less bell-like in trunk-based coordinates than in external coordinates. Taken together, these results support the conclusion that turn-and-reach movements are controlled in an external frame of reference.

Effects of electromyography-driven robot-aided hand training with neuromuscular electrical stimulation on hand control performance after chronic stroke.

PubMed

Rong, Wei; Tong, Kai Yu; Hu, Xiao Ling; Ho, Sze Kit

2015-03-01

An electromyography-driven robot system integrated with neuromuscular electrical stimulation (NMES) was developed to investigate its effectiveness on post-stroke rehabilitation. The performance of this system in assisting finger flexion/extension with different assistance combinations was evaluated in five stroke subjects. Then, a pilot study with 20-sessions training was conducted to evaluate the training's effectiveness. The results showed that combined assistance from the NMES-robot could improve finger movement accuracy, encourage muscle activation of the finger muscles and suppress excessive muscular activities in the elbow joint. When assistances from both NMES and the robot were 50% of their maximum assistances, finger-tracking performance had the best results, with the lowest root mean square error, greater range of motion, higher voluntary muscle activations of the finger joints and lower muscle co-contraction in the finger and elbow joints. Upper limb function improved after the 20-session training, indicated by the increased clinical scores of Fugl-Meyer Assessment, Action Research Arm Test and Wolf Motor Function Test. Muscle co-contraction was reduced in the finger and elbow joints reflected by the Modified Ashworth Scale. The findings demonstrated that an electromyography-driven NMES-robot used for chronic stroke improved hand function and tracking performance. Further research is warranted to validate the method on a larger scale. Implications for Rehabilitation The hand robotics and neuromuscular electrical stimulation (NMES) techniques are still separate systems in current post-stroke hand rehabilitation. This is the first study to investigate the combined effects of the NMES and robot on hand rehabilitation. The finger tracking performance was improved with the combined assistance from the EMG-driven NMES-robot hand system. The assistance from the robot could improve the finger movement accuracy and the assistance from the NMES could reduce the muscle co-contraction on finger and elbow joints. The upper limb functions were improved on chronic stroke patients after the pilot study of 20-session hand training with the combined assistance from the EMG-driven NMES-robot. The muscle spasticity on finger and elbow joints was reduced after the training.

Arthrodesis of the proximal interphalangeal joint of the 4th and 5th finger using an interlocking screw device to treat severe recurrence of Dupuytren's disease.

PubMed

Novoa-Parra, C D; Montaner-Alonso, D; Pérez-Correa, J I; Morales-Rodríguez, J; Rodrigo-Pérez, J L; Morales-Suarez-Varela, M

To assess the radiological and functional outcome of arthrodesis of the 4th and 5th finger using the APEX™ (Extremity Medical, Parsippany,NJ)intermedullary interlocking screw system in patients with severe recurrence of Dupuytren's disease. The DASH questionnaire and the VAS scale were used to assess the clinical outcomes. The angle of arthrodesis, fusion time and implant fixation were evaluated on x-rays. The patients were monitored for complications during surgery and the follow-up period. The sample comprised 6 patients. Mean follow up was 19.6 months. All of the patients presented clinical and radiological evidence of fusion at 8 weeks, with fusion angles of 30° (3) and 45° (3). There were no complications and none of the implants had to be removed. The functional outcomes in these patients were poor. The system offers a reliable method for IPJ arthrodesis at a precise angle. It promotes stable fixation that does not require prolonged immobilisation. It can be used together with other procedures on the hand with severe recurrence of DD. The functional outcomes for this group of patients using this device were poor. Copyright © 2017 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

Imaging osteoarthritis in the knee joints using x-ray guided diffuse optical tomography

NASA Astrophysics Data System (ADS)

Zhang, Qizhi; Yuan, Zhen; Sobel, Eric S.; Jiang, Huabei

2010-02-01

In our previous studies, near-infrared (NIR) diffuse optical tomography (DOT) had been successfully applied to imaging osteoarthritis (OA) in the finger joints where significant difference in optical properties of the joint tissues was evident between healthy and OA finger joints. Here we report for the first time that large joints such as the knee can also be optically imaged especially when DOT is combined with x-ray tomosynthesis where the 3D image of the bones from x-ray is incorporated into the DOT reconstruction as spatial a priori structural information. This study demonstrates that NIR light can image large joints such as the knee in addition to finger joints, which will drastically broaden the clinical utility of our x-ray guided DOT technique for OA diagnosis.

Estimation of continuous multi-DOF finger joint kinematics from surface EMG using a multi-output Gaussian Process.

PubMed

Ngeo, Jimson; Tamei, Tomoya; Shibata, Tomohiro

2014-01-01

Surface electromyographic (EMG) signals have often been used in estimating upper and lower limb dynamics and kinematics for the purpose of controlling robotic devices such as robot prosthesis and finger exoskeletons. However, in estimating multiple and a high number of degrees-of-freedom (DOF) kinematics from EMG, output DOFs are usually estimated independently. In this study, we estimate finger joint kinematics from EMG signals using a multi-output convolved Gaussian Process (Multi-output Full GP) that considers dependencies between outputs. We show that estimation of finger joints from muscle activation inputs can be improved by using a regression model that considers inherent coupling or correlation within the hand and finger joints. We also provide a comparison of estimation performance between different regression methods, such as Artificial Neural Networks (ANN) which is used by many of the related studies. We show that using a multi-output GP gives improved estimation compared to multi-output ANN and even dedicated or independent regression models.

Improving the fatigue resistance of adhesive joints in laminated wood structures

NASA Technical Reports Server (NTRS)

Laufenberg, Theodore L.; River, Bryan H.; Murmanis, Lidija L.; Christiansen, Alfred W.

1988-01-01

The premature fatigue failure of a laminated wood/epoxy test beam containing a cross section finger joint was the subject of a multi-disciplinary investigation. The primary objectives were to identify the failure mechanisms which occurred during the finger joint test and to provide avenues for general improvements in the design and fabrication of adhesive joints in laminated wood structures.

Outcomes of Silicone Arthroplasty Stratified by Fingers for the Rheumatoid Metacarpophalangeal Joints

PubMed Central

Chung, Kevin C.; Kotsis, Sandra V.; Shaw Wilgis, E. F.; Fox, David A.; Regan, Marian; Kim, H. Myra; Burke, Frank D.

2015-01-01

Purpose Previous studies have demonstrated that outcomes for the ulnar digits appear to be worse than the radial digits after silicone metacarpophalangeal joint arthroplasty (SMPA) for the rheumatoid hand. This study examines various components of hand deformities in an effort to understand SMPA outcomes in terms of metacarpophalangeal joint range of motion and alignment. We hypothesize that the ulnar fingers will have less improvement marked by greater ulnar drift, extension lag, and less metacarpophalangeal joint (MCPJ) arc of motion than the radial fingers. Methods 68 surgical patients were recruited from 3 sites in this multi-center international prospective cohort study. All patients had a diagnosis of rheumatoid arthritis, were between the ages of 18–80, and were eligible to undergo SMPA based on measured hand deformities (extensor lag and ulnar drift). Ulnar drift, extension lag, and arc of motion for the MCPJ of each finger were measured at baseline (pre-surgical) and 1-year after SMPA. Results All fingers showed an improvement in ulnar drift from baseline to 1-year after surgery. The smallest improvement was in the index finger (12°) and the largest improvement was in the little finger (30°). Similarly, the largest improvement in extension lag was seen in the little finger (47°) and the smallest improvement was seen in the index finger (21°). In terms of MCPJ arc of motion, all fingers moved to a more extended posture and gained an improved arc of motion, but the biggest improvement was observed in the 2 ulnar fingers and less so in the 2 radial fingers. Conclusions Our hypothesis that the ulnar fingers will have worse outcomes than the radial fingers is not proven by this study. Although past experiences have indicated that it is more difficult to maintain posture for the ring and little fingers after SMPA due to the deforming forces, sufficient correction of the deformities in the ulnar fingers is possible, if attention to adequate bone resection and realigning of the extensor mechanism are carefully performed during the procedure. PMID:19896008

Changes in the flexor digitorum profundus tendon geometry in the carpal tunnel due to force production and posture of metacarpophalangeal joint of the index finger: an MRI study.

PubMed

Martin, Joel R; Paclet, Florent; Latash, Mark L; Zatsiorsky, Vladimir M

2013-02-01

Carpal tunnel syndrome is a disorder caused by increased pressure in the carpal tunnel associated with repetitive, stereotypical finger actions. Little is known about in vivo geometrical changes in the carpal tunnel caused by motion at the finger joints and exerting a fingertip force. The hands and forearms of five subjects were scanned using a 3.0 T magnetic resonance imaging scanner. The metacarpophalangeal joint of the index finger was placed in: flexion, neutral and extension. For each joint posture subjects either produced no active force (passive condition) or exerted a flexion force to resist a load (~4.0 N) at the fingertip (active condition). Changes in the radii of curvature, position and transverse plane area of the flexor digitorum profundus tendons at the carpal tunnel level were measured. The radius of curvature of the flexor digitorum profundus tendons, at the carpal tunnel level, was significantly affected by posture of the index finger metacarpophalangeal joint (P<0.05) and the radii was significantly different between fingers (P<0.05). Actively producing force caused a significant shift (P<0.05) in the flexor digitorum profundus tendons in the ventral (palmar) direction. No significant change in the area of an ellipse containing the flexor digitorum profundus tendons was observed between conditions. The results show that relatively small changes in the posture and force production of a single finger can lead to significant changes in the geometry of all the flexor digitorum profundus tendons in the carpal tunnel. Additionally, voluntary force production at the fingertip increases the moment arm of the FDP tendons about the wrist joint. Copyright © 2012 Elsevier Ltd. All rights reserved.

Skin strain patterns provide kinaesthetic information to the human central nervous system.

PubMed Central

Edin, B B; Johansson, N

1995-01-01

1. We investigated the contribution of skin strain-related sensory inputs to movement perception and execution in five normal volunteers. The dorsal and palmar skin of the middle phalanx and the proximal interphalangeal (PIP) joint were manipulated to generate specific strain patterns in the proximal part of the index finger. To mask sensations directly related to this manipulation, skin and deeper tissues were blocked distal to the mid-portion of the proximal phalanx of the index finger by local anaesthesia. 2. Subjects were asked to move their normal right index finger either to mimic any perceived movements of the anaesthetized finger or to touch the tip of the insentient finger. 3. All subjects readily reproduced actual movements induced by the experimenter at the anaesthetized PIP joint. However, all subjects also generated flexion movements when the experimenter did not induce actual movement but produced deformations in the sentient proximal skin that were similar to those observed during actual PIP joint flexion. Likewise, the subjects indicated extension movement at the PIP joint when strain patterns corresponding to extension movements were induced. 4. In contrast, when the skin strain in the proximal part of the index finger was damped by a ring applied just proximal to the PIP joint within the anaesthetized skin area, both tested subjects failed to perceive PIP movements that actually took place.(ABSTRACT TRUNCATED AT 250 WORDS) Images Figure 2 Figure 3 PMID:7473253

[Microsurgery for severe flexion contracture of proximal interphalangeal joint].

PubMed

Fei, Xiaoxuan; Feng, Shiming; Gao, Shunhong

2012-07-01

To investigate the clinical results of cross-finger flap combined with laterodigital pedicled skin flap for repair of severe flexion contracture of the proximal interphalangeal joint. Between October 2008 and February 2011, 11 patients (11 fingers) with severe flexion contracture of the proximal interphalangeal joint were treated with cross-finger flap combined with laterodigital pedicled skin flap. There were 7 males and 4 females, aged 20-63 years (mean, 32.6 years). The causes of injury were crush or electric-saw injury in 7 cases, burn or explosive injury in 3 cases, and electrical injury in 1 case. The locations were the index finger in 4 cases, the middle finger in 2 cases, the ring finger in 2 cases, and the little finger in 3 cases. The mean disease duration was 12.4 months (range, 6-24 months). All cases were rated as type III according to Stern classification standard. The volar tissue defect ranged from 3.0 cm x 1.5 cm to 5.0 cm x 2.5 cm, with exposed tendons, nerves, vessels, or bone after scar relaxation. The defects were repaired with cross-finger flaps (2.2 cm x 1.8 cm to 3.8 cm x 2.5 cm) combined with laterodigital pedicled skin flaps (1.5 cm x 1.2 cm to 2.5 cm x 2.0 cm). Double laterodigital pedicled skin flaps were used in 3 cases. The flap donor site was sutured directly or repaired with the skin graft. All flaps survived completely and wound healed by first intention. The donor skin graft survived. All the patients were followed up 6-18 months (mean, 11.3 months). The finger appearance was satisfactory. The flaps had soft texture and good color in all cases. No obvious pigmentation or contraction was observed. The contracted fingers could extend completely with good active flexion and extension motion. At last follow-up, the extension of the proximal interphalangeal joint was 10-150. Based on proximal interphalangeal joint motion standard of Chinese Medical Association for hand surgery, the results were excellent in 6 cases, good in 4 cases, and fair in 1 case; the excellent and good rate was 90.9%. It is an easy and simple therapy t o cover wound area of severe flexion contracture of the proximal interphalangeal joint after scar relaxation using cross-finger flap combined with laterodigital pedicled skin flap, which can repair large defect and achieve good results in finger appearance and function.

A new approach to depict bone surfaces in finger imaging using photoacoustic tomography

NASA Astrophysics Data System (ADS)

Biswas, S. K.; van Es, P.; Steenbergen, W.; Manohar, S.

2015-03-01

Imaging the vasculature close around the finger joints is of interest in the field of rheumatology. Locally increased vasculature in the synovial membrane of these joints can be a marker for rheumatoid arthritis. In previous work we showed that part of the photoacoustically induced ultrasound from the epidermis reflects on the bone surface within the finger. These reflected signals could be wrongly interpreted as new photoacoustic sources. In this work we show that a conventional ultrasound reconstruction algorithm, that considers the skin as a collection of ultrasound transmitters and the PA tomography probe as the detector array, can be used to delineate bone surfaces of a finger. This can in the future assist in the localization of the joint gaps. This can provide us with a landmark to localize the region of the inflamed synovial membrane. We test the approach on finger mimicking phantoms.

Hypothyroidism presenting as destructive arthropathy of the fingers.

PubMed Central

Gerster, J. C.; Quadri, P.; Saudan, Y.

1985-01-01

A patient presenting with destructive arthropathy of the proximal interphalangeal (PIP) joints of the hands is described. She was initially believed to have rheumatoid arthritis but non-steroidal anti-inflammatory drugs were of no help. The patient was subsequently found to have hypothyroidism and erosive osteoarthritis of the fingers. Joint swelling, pain and stiffness responded dramatically to thyroid hormone substitution. The PIP joint spaces reappeared on the radiographs within 9 months. This case suggest that hypothyroidism may induce destructive arthropathy of the finger joints. As thyroxine replacement may reverse the rheumatic complaints, hypothyroidism should be considered in the differential diagnosis of a destructive arthropathy of unclear aetiology. Images Figure 1 Figure 2 PMID:3983045

Traumatic synovitis in a classical guitarist: a study of joint laxity.

PubMed

Bird, H A; Wright, V

1981-04-01

A classical guitarist performing for at least 5 hours each day developed a traumatic synovitis at the left wrist joint that was first erroneously considered to be rheumatoid arthritis. Comparison with members of the same guitar class suggested that unusual joint laxity of the fingers and wrist, probably inherited from the patient's father, was of more importance in the aetiology of the synovitis than a wide range of movement acquired by regular practice. Hyperextension of the metacarpophalangeal joint of the left index finger, quantified by the hyperextensometer, was less marked in the guitarists than in 100 normal individuals. This may be attributed to greater muscular control of the fingers. Lateral instability in the loaded joint may be the most important factor in the aetiology of traumatic synovitis.

Traumatic synovitis in a classical guitarist: a study of joint laxity.

PubMed Central

Bird, H A; Wright, V

1981-01-01

A classical guitarist performing for at least 5 hours each day developed a traumatic synovitis at the left wrist joint that was first erroneously considered to be rheumatoid arthritis. Comparison with members of the same guitar class suggested that unusual joint laxity of the fingers and wrist, probably inherited from the patient's father, was of more importance in the aetiology of the synovitis than a wide range of movement acquired by regular practice. Hyperextension of the metacarpophalangeal joint of the left index finger, quantified by the hyperextensometer, was less marked in the guitarists than in 100 normal individuals. This may be attributed to greater muscular control of the fingers. Lateral instability in the loaded joint may be the most important factor in the aetiology of traumatic synovitis. Images PMID:7224687

Robotic Finger Assembly

NASA Technical Reports Server (NTRS)

Ihrke, Chris A. (Inventor); Diftler, Myron A. (Inventor); Askew, Scott R. (Inventor); Linn, Douglas Martin (Inventor); Platt, Robert J., Jr. (Inventor); Bridgwater, Lyndon (Inventor); Hargrave, Brian (Inventor); Valvo, Michael C. (Inventor)

2014-01-01

A robotic hand includes a finger with first, second, and third phalanges. A first joint rotatably connects the first phalange to a base structure. A second joint rotatably connects the first phalange to the second phalange. A third joint rotatably connects the third phalange to the second phalange. The second joint and the third joint are kinematically linked such that the position of the third phalange with respect to the second phalange is determined by the position of the second phalange with respect to the first phalange.

Robotic Finger Assembly

NASA Technical Reports Server (NTRS)

Ihrke, Chris A. (Inventor); Bridgwater, Lyndon (Inventor); Diftler, Myron A. (Inventor); Linn, Douglas M. (Inventor); Platt, Robert (Inventor); Hargrave, Brian (Inventor); Askew, Scott R. (Inventor); Valvo, Michael C. (Inventor)

2013-01-01

A robotic hand includes a finger with first, second, and third phalanges. A first joint rotatably connects the first phalange to a base structure. A second joint rotatably connects the first phalange to the second phalange. A third joint rotatably connects the third phalange to the second phalange. The second joint and the third joint are kinematically linked such that the position of the third phalange with respect to the second phalange is determined by the position of the second phalange with respect to the first phalange.

Change of synovial vascularity in a single finger joint assessed by power doppler sonography correlated with radiographic change in rheumatoid arthritis: comparative study of a novel quantitative score with a semiquantitative score.

PubMed

Fukae, Jun; Kon, Yujiro; Henmi, Mihoko; Sakamoto, Fumihiko; Narita, Akihiro; Shimizu, Masato; Tanimura, Kazuhide; Matsuhashi, Megumi; Kamishima, Tamotsu; Atsumi, Tatsuya; Koike, Takao

2010-05-01

To investigate the relationship between synovial vascularity assessed by quantitative power Doppler sonography (PDS) and progression of structural bone damage in a single finger joint in patients with rheumatoid arthritis (RA). We studied 190 metacarpophalangeal (MCP) joints and 190 proximal interphalangeal (PIP) joints of 19 patients with active RA who had initial treatment with disease-modifying antirheumatic drugs (DMARDs). Patients were examined by clinical and laboratory assessments throughout the study. Hand and foot radiography was performed at baseline and the twentieth week. Magnetic resonance imaging (MRI) was performed at baseline. PDS was performed at baseline and the eighth week. Synovial vascularity was evaluated according to both quantitative and semiquantitative methods. Quantitative PDS was significantly correlated with the enhancement rate of MRI in each single finger joint. Comparing quantitative synovial vascularity and radiographic change in single MCP or PIP joints, the level of vascularity at baseline showed a significant positive correlation with radiographic progression at the twentieth week. The change of vascularity in response to DMARDs, defined as the percentage change in vascularity by the eighth week from baseline, was inversely correlated with radiographic progression in each MCP joint. The quantitative PDS method was more useful than the semiquantitative method for the evaluation of synovial vascularity in a single finger joint. The change of synovial vascularity in a single finger joint determined by quantitative PDS could numerically predict its radiographic progression. Using vascularity as a guide to consider a therapeutic approach would have benefits for patients with active RA.

Control of an optimal finger exoskeleton based on continuous joint angle estimation from EMG signals.

PubMed

Ngeo, Jimson; Tamei, Tomoya; Shibata, Tomohiro; Orlando, M F Felix; Behera, Laxmidhar; Saxena, Anupam; Dutta, Ashish

2013-01-01

Patients suffering from loss of hand functions caused by stroke and other spinal cord injuries have driven a surge in the development of wearable assistive devices in recent years. In this paper, we present a system made up of a low-profile, optimally designed finger exoskeleton continuously controlled by a user's surface electromyographic (sEMG) signals. The mechanical design is based on an optimal four-bar linkage that can model the finger's irregular trajectory due to the finger's varying lengths and changing instantaneous center. The desired joint angle positions are given by the predictive output of an artificial neural network with an EMG-to-Muscle Activation model that parameterizes electromechanical delay (EMD). After confirming good prediction accuracy of multiple finger joint angles we evaluated an index finger exoskeleton by obtaining a subject's EMG signals from the left forearm and using the signal to actuate a finger on the right hand with the exoskeleton. Our results show that our sEMG-based control strategy worked well in controlling the exoskeleton, obtaining the intended positions of the device, and that the subject felt the appropriate motion support from the device.

Computer-aided classification of rheumatoid arthritis in finger joints using frequency domain optical tomography

NASA Astrophysics Data System (ADS)

Klose, C. D.; Kim, H. K.; Netz, U.; Blaschke, S.; Zwaka, P. A.; Mueller, G. A.; Beuthan, J.; Hielscher, A. H.

2009-02-01

Novel methods that can help in the diagnosis and monitoring of joint disease are essential for efficient use of novel arthritis therapies that are currently emerging. Building on previous studies that involved continuous wave imaging systems we present here first clinical data obtained with a new frequency-domain imaging system. Three-dimensional tomographic data sets of absorption and scattering coefficients were generated for 107 fingers. The data were analyzed using ANOVA, MANOVA, Discriminant Analysis DA, and a machine-learning algorithm that is based on self-organizing mapping (SOM) for clustering data in 2-dimensional parameter spaces. Overall we found that the SOM algorithm outperforms the more traditional analysis methods in terms of correctly classifying finger joints. Using SOM, healthy and affected joints can now be separated with a sensitivity of 0.97 and specificity of 0.91. Furthermore, preliminary results suggest that if a combination of multiple image properties is used, statistical significant differences can be found between RA-affected finger joints that show different clinical features (e.g. effusion, synovitis or erosion).

Cortex Inspired Model for Inverse Kinematics Computation for a Humanoid Robotic Finger

PubMed Central

Gentili, Rodolphe J.; Oh, Hyuk; Molina, Javier; Reggia, James A.; Contreras-Vidal, José L.

2013-01-01

In order to approach human hand performance levels, artificial anthropomorphic hands/fingers have increasingly incorporated human biomechanical features. However, the performance of finger reaching movements to visual targets involving the complex kinematics of multi-jointed, anthropomorphic actuators is a difficult problem. This is because the relationship between sensory and motor coordinates is highly nonlinear, and also often includes mechanical coupling of the two last joints. Recently, we developed a cortical model that learns the inverse kinematics of a simulated anthropomorphic finger. Here, we expand this previous work by assessing if this cortical model is able to learn the inverse kinematics for an actual anthropomorphic humanoid finger having its two last joints coupled and controlled by pneumatic muscles. The findings revealed that single 3D reaching movements, as well as more complex patterns of motion of the humanoid finger, were accurately and robustly performed by this cortical model while producing kinematics comparable to those of humans. This work contributes to the development of a bioinspired controller providing adaptive, robust and flexible control of dexterous robotic and prosthetic hands. PMID:23366569

High-resolution x-ray guided three-dimensional diffuse optical tomography of joint tissues in hand osteoarthritis: Morphological and functional assessments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuan Zhen; Zhang Qizhi; Sobel, Eric S.

Purpose: The aim of this study was to investigate the potential use of multimodality functional imaging techniques to identify the quantitative optical findings that can be used to distinguish between osteoarthritic and normal finger joints. Methods: Between 2006 and 2009, the distal interphalangeal finger joints from 40 female subjects including 22 patients and 18 healthy controls were examined clinically and scanned by a hybrid imaging system. This system integrated x-ray tomosynthetic setup with a diffuse optical imaging system. Optical absorption and scattering images were recovered based on a regularization-based hybrid reconstruction algorithm. A receiver operating characteristic curve was used tomore » calculate the statistical significance of specific optical features obtained from osteoarthritic and healthy joints groups. Results: The three-dimensional optical and x-ray images captured made it possible to quantify optical properties and joint space width of finger joints. Based on the recovered optical absorption and scattering parameters, the authors observed statistically significant differences between healthy and osteoarthritis finger joints. Conclusions: The statistical results revealed that sensitivity and specificity values up to 92% and 100%, respectively, can be achieved when optical properties of joint tissues were used as classifiers. This suggests that these optical imaging parameters are possible indicators for diagnosing osteoarthritis and monitoring its progression.« less

A cortically-inspired model for inverse kinematics computation of a humanoid finger with mechanically coupled joints.

PubMed

Gentili, Rodolphe J; Oh, Hyuk; Kregling, Alissa V; Reggia, James A

2016-05-19

The human hand's versatility allows for robust and flexible grasping. To obtain such efficiency, many robotic hands include human biomechanical features such as fingers having their two last joints mechanically coupled. Although such coupling enables human-like grasping, controlling the inverse kinematics of such mechanical systems is challenging. Here we propose a cortical model for fine motor control of a humanoid finger, having its two last joints coupled, that learns the inverse kinematics of the effector. This neural model functionally mimics the population vector coding as well as sensorimotor prediction processes of the brain's motor/premotor and parietal regions, respectively. After learning, this neural architecture could both overtly (actual execution) and covertly (mental execution or motor imagery) perform accurate, robust and flexible finger movements while reproducing the main human finger kinematic states. This work contributes to developing neuro-mimetic controllers for dexterous humanoid robotic/prosthetic upper-extremities, and has the potential to promote human-robot interactions.

Hand rehabilitation after stroke using a wearable, high DOF, spring powered exoskeleton.

PubMed

Tianyao Chen; Lum, Peter S

2016-08-01

Stroke patients often have inappropriate finger flexor activation and finger extensor weakness, which makes it difficult to open their affected hand for functional grasp. The goal was to develop a passive, lightweight, wearable device to enable improved hand function during performance of activities of daily living. The device, HandSOME II, assists with opening the patient's hand using 11 elastic actuators that apply extension torques to finger and thumb joints. Device design and initial testing are described. A novel mechanical design applies forces orthogonal to the finger segments despite the fact that all of the device DOFs are not aligned with human joint DOF. In initial testing with seven stroke subjects with impaired hand function, use of HandSOME II significantly increased maximum extension angles and range of motion in all of the index finger joints (P<;0.05). HandSOME II allows performance of all the grip patterns used in daily activities and can be used as part of home-based therapy programs.

SU-E-T-171: Evaluation of the Analytical Anisotropic Algorithm in a Small Finger Joint Phantom Using Monte Carlo Simulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chow, J; Owrangi, A; Jiang, R

2014-06-01

Purpose: This study investigated the performance of the anisotropic analytical algorithm (AAA) in dose calculation in radiotherapy concerning a small finger joint. Monte Carlo simulation (EGSnrc code) was used in this dosimetric evaluation. Methods: Heterogeneous finger joint phantom containing a vertical water layer (bone joint or cartilage) sandwiched by two bones with dimension 2 × 2 × 2 cm{sup 3} was irradiated by the 6 MV photon beams (field size = 4 × 4 cm{sup 2}). The central beam axis was along the length of the bone joint and the isocenter was set to the center of the joint. Themore » joint width and beam angle were varied from 0.5–2 mm and 0°–15°, respectively. Depth doses were calculated using the AAA and DOSXYZnrc. For dosimetric comparison and normalization, dose calculations were repeated in water phantom using the same beam geometry. Results: Our AAA and Monte Carlo results showed that the AAA underestimated the joint doses by 10%–20%, and could not predict joint dose variation with changes of joint width and beam angle. The calculated bone dose enhancement for the AAA was lower than Monte Carlo and the depth of maximum dose for the phantom was smaller than that for the water phantom. From Monte Carlo results, there was a decrease of joint dose as its width increased. This reflected the smaller the joint width, the more the bone scatter contributed to the depth dose. Moreover, the joint dose was found slightly decreased with an increase of beam angle. Conclusion: The AAA could not handle variations of joint dose well with changes of joint width and beam angle based on our finger joint phantom. Monte Carlo results showed that the joint dose decreased with increase of joint width and beam angle. This dosimetry comparison should be useful to radiation staff in radiotherapy related to small bone joint.« less

Distinct Inter-Joint Coordination during Fast Alternate Keystrokes in Pianists with Superior Skill.

PubMed

Furuya, Shinichi; Goda, Tatsushi; Katayose, Haruhiro; Miwa, Hiroyoshi; Nagata, Noriko

2011-01-01

Musical performance requires motor skills to coordinate the movements of multiple joints in the hand and arm over a wide range of tempi. However, it is unclear whether the coordination of movement across joints would differ for musicians with different skill levels and how inter-joint coordination would vary in relation to music tempo. The present study addresses these issues by examining the kinematics and muscular activity of the hand and arm movements of professional and amateur pianists who strike two keys alternately with the thumb and little finger at various tempi. The professionals produced a smaller flexion velocity at the thumb and little finger and greater elbow pronation and supination velocity than did the amateurs. The experts also showed smaller extension angles at the metacarpo-phalangeal joint of the index and middle fingers, which were not being used to strike the keys. Furthermore, muscular activity in the extrinsic finger muscles was smaller for the experts than for the amateurs. These findings indicate that pianists with superior skill reduce the finger muscle load during keystrokes by taking advantage of differences in proximal joint motion and hand postural configuration. With an increase in tempo, the experts showed larger and smaller increases in elbow velocity and finger muscle co-activation, respectively, compared to the amateurs, highlighting skill level-dependent differences in movement strategies for tempo adjustment. Finally, when striking as fast as possible, individual differences in the striking tempo among players were explained by their elbow velocities but not by their digit velocities. These findings suggest that pianists who are capable of faster keystrokes benefit more from proximal joint motion than do pianists who are not capable of faster keystrokes. The distinct movement strategy for tempo adjustment in pianists with superior skill would therefore ensure a wider range of musical expression.

Distinct Inter-Joint Coordination during Fast Alternate Keystrokes in Pianists with Superior Skill

PubMed Central

Furuya, Shinichi; Goda, Tatsushi; Katayose, Haruhiro; Miwa, Hiroyoshi; Nagata, Noriko

2011-01-01

Musical performance requires motor skills to coordinate the movements of multiple joints in the hand and arm over a wide range of tempi. However, it is unclear whether the coordination of movement across joints would differ for musicians with different skill levels and how inter-joint coordination would vary in relation to music tempo. The present study addresses these issues by examining the kinematics and muscular activity of the hand and arm movements of professional and amateur pianists who strike two keys alternately with the thumb and little finger at various tempi. The professionals produced a smaller flexion velocity at the thumb and little finger and greater elbow pronation and supination velocity than did the amateurs. The experts also showed smaller extension angles at the metacarpo-phalangeal joint of the index and middle fingers, which were not being used to strike the keys. Furthermore, muscular activity in the extrinsic finger muscles was smaller for the experts than for the amateurs. These findings indicate that pianists with superior skill reduce the finger muscle load during keystrokes by taking advantage of differences in proximal joint motion and hand postural configuration. With an increase in tempo, the experts showed larger and smaller increases in elbow velocity and finger muscle co-activation, respectively, compared to the amateurs, highlighting skill level-dependent differences in movement strategies for tempo adjustment. Finally, when striking as fast as possible, individual differences in the striking tempo among players were explained by their elbow velocities but not by their digit velocities. These findings suggest that pianists who are capable of faster keystrokes benefit more from proximal joint motion than do pianists who are not capable of faster keystrokes. The distinct movement strategy for tempo adjustment in pianists with superior skill would therefore ensure a wider range of musical expression. PMID:21660290

SEPs to finger joint input lack the N20-P20 response that is evoked by tactile inputs: contrast between cortical generators in areas 3b and 2 in humans.

PubMed

Desmedt, J E; Ozaki, I

1991-01-01

A method using a DC servo motor is described to produce brisk angular movements at finger interphalangeal joints in humans. Small passive flexions of 2 degrees elicited sizable somatosensory evoked potentials (SEPs) starting with a contralateral positive P34 parietal response thought to reflect activation of a radial equivalent dipole generator in area 2 which receives joint inputs. By contrast, electric stimulation of tactile (non-joint) inputs from the distal phalanx evoked the usual contralateral negative N20 reflecting a tangential equivalent dipole generator in area 3b. Finger joint inputs also evoked a precentral positivity equivalent to the P22 of motor area 4, and a large frontal negativity equivalent to N30. It is suggested that natural stimulation allows human SEP components to be differentiated in conjunction with distinct cortical somatotopic projections.

Distractor objects affect fingers' angular distances but not fingers' shaping during grasping.

PubMed

Ansuini, Caterina; Tognin, Veronica; Turella, Luca; Castiello, Umberto

2007-04-01

The aim of the present study was to determine whether and how hand shaping was affected by the presence of a distractor object adjacent to the to-be-grasped object. Twenty subjects were requested to reach towards and grasp a 'convex' or a 'concave' object in the presence or absence of a distractor object either of the same or different shape than the target object. Flexion/extension at the metacarpal-phalangeal (MCP) and proximal interphalangeal joints of all digits, and abduction angle between digits were measured by resistive sensors embedded in a glove. The results indicate robust interference effects at the level of reach duration and the extent of fingers' abduction angles together with changes at the level of a single joint for the thumb. No distractor effects on individual fingers' joints except for the MCP of the middle and little fingers were found. These findings suggest that the presence of distractor object affects hand shaping in terms of fingers' abduction angles, but not at the level of 'shape dependent' fingers' angular excursions. Furthermore, they support the importance of the thumb for the guidance of selective reach-to-grasp movements. We discuss these results in the context of current theories proposed to explain the object selection processes underlying the control of hand action.

A hydrogel actuator with flexible folding deformation and shape programming via using sodium carboxymethyl cellulose and acrylic acid.

PubMed

Wu, Shuiping; Yu, Feng; Dong, Hua; Cao, Xiaodong

2017-10-01

Hydrogel actuator is an intelligent material, which can work as artificial muscle. However, most present hydrogel actuators, due to the inferior mechanical property and uncontrolled folding property, have always resulted in slipping off or the failure of grasping an object with specific shape and required weight. In order to solve this problem, here a tough hydrogel actuator with programmable folding deformation has been prepared by combining the "selective implanting method" and "ionic coordination". The shape and folding angle (from 0 to 180 o ) of hydrogel actuator can be precisely controlled by altering the location and size of the implanting parts that seems like the joints of finger. The ionic coordination is not only the force to trigger the folding of hydrogel, but also utilized to reinforce the mechanical property. We believed the superior mechanical and shape-programmable property can endow the hydrogel actuator with great application prospect in soft machine. Copyright © 2017 Elsevier Ltd. All rights reserved.

Radiographic hand osteoarthritis: patterns and associations with hand pain and function in a community-dwelling sample.

PubMed

Marshall, M; van der Windt, D; Nicholls, E; Myers, H; Hay, E; Dziedzic, K

2009-11-01

Patterns of radiographic osteoarthritis (ROA) of the hand are often examined by row, with the four joints of the thumb studied inconsistently. The objectives of this study were to determine relationships of ROA at different hand joints, use the findings to define radiographic sub-groups and investigate their associations with pain and function. Sixteen joints in each hand were scored for the presence of ROA in a community-dwelling cohort of adults, 50-years-and-over, with self-reported hand pain or problems. Principal components analysis (PCA) with varimax rotation was used to study patterns of ROA in the hand joints and identify distinct sub-groups. Differences in pain and function between these sub-groups were assessed using Australian/Canadian Osteoarthritis Index (AUSCAN), Grip Ability Test (GAT) and grip and pinch strength. PCA was undertaken on data from 592 participants and identified four components: distal interphalangeal joints (DIPs), proximal interphalangeal joints (PIPs), metacarpophalangeal joints (MCPs), thumb joints. However, the left thumb interphalangeal (IP) joint cross-loaded with the PIP and thumb groups. On this basis, participants were categorised into four radiographic sub-groups: no osteoarthritis (OA), finger only OA, thumb only OA and combined thumb and finger OA. Statistically significant differences were found between the sub-groups for AUSCAN function, and in women alone for grip and pinch strength. Participants with combined thumb and finger OA had the worst scores. Individual thumb joints can be clustered together as a joint group in ROA. Four radiographic sub-groups of hand OA can be distinguished. Pain and functional difficulties were highest in participants with both thumb and finger OA.

Initial results of finger imaging using photoacoustic computed tomography

NASA Astrophysics Data System (ADS)

van Es, Peter; Biswas, Samir K.; Moens, Hein J. Bernelot; Steenbergen, Wiendelt; Manohar, Srirang

2014-06-01

We present a photoacoustic computed tomography investigation on a healthy human finger, to image blood vessels with a focus on vascularity across the interphalangeal joints. The cross-sectional images were acquired using an imager specifically developed for this purpose. The images show rich detail of the digital blood vessels with diameters between 100 μm and 1.5 mm in various orientations and at various depths. Different vascular layers in the skin including the subpapillary plexus could also be visualized. Acoustic reflections on the finger bone of photoacoustic signals from skin were visible in sequential slice images along the finger except at the location of the joint gaps. Not unexpectedly, the healthy synovial membrane at the joint gaps was not detected due to its small size and normal vascularization. Future research will concentrate on studying digits afflicted with rheumatoid arthritis to detect the inflamed synovium with its heightened vascularization, whose characteristics are potential markers for disease activity.

Simulation of light transport in arthritic- and non-arthritic human fingers

NASA Astrophysics Data System (ADS)

Milanic, Matija; Paluchowski, Lukasz A.; Randeberg, Lise L.

2014-03-01

Rheumatoid arthritis is a disease that frequently leads to joint destruction. It has high incidence rates worldwide, and the disease significantly reduces patient's quality of life due to pain, swelling and stiffness of the affected joints. Early diagnosis is necessary to improve course of the disease, therefore sensitive and accurate diagnostic tools are required. Optical imaging techniques have capability for early diagnosis and monitoring of arthritis. As compared to conventional diagnostic techniques optical technique is a noninvasive, noncontact and fast way of collecting diagnostic information. However, a realistic model of light transport in human joints is needed for understanding and developing of such optical diagnostic tools. The aim of this study is to develop a 3D numerical model of light transport in a human finger. The model will guide development of a hyperspectral imaging (HSI) diagnostic modality for arthritis in human fingers. The implemented human finger geometry is based on anatomical data. Optical data of finger tissues are adjusted to represent either an arthritic or an unaffected finger. The geometry and optical data serve as input into a 3D Monte Carlo method, which calculate diffuse reflectance, transmittance and absorbed energy distributions. The parameters of the model are optimized based on HIS-measurements of human fingers. The presented model serves as an important tool for understanding and development of HSI as an arthritis diagnostic modality. Yet, it can be applied to other optical techniques and finger diseases.

Reoperations following proximal interphalangeal joint nonconstrained arthroplasties.

PubMed

Pritsch, Tamir; Rizzo, Marco

2011-09-01

To retrospectively analyze the reasons for reoperations following primary nonconstrained proximal interphalangeal (PIP) joint arthroplasty and review clinical outcomes in this group of patients with 1 or more reoperations. Between 2001 and 2009, 294 nonconstrained (203 pyrocarbon and 91 metal-plastic) PIP joint replacements were performed in our institution. A total of 76 fingers (59 patients) required reoperation (50 pyrocarbon and 26 metal-plastic). There were 40 women and 19 men with an average age of 51 years (range, 19-83 y). Primary diagnoses included osteoarthritis in 35, posttraumatic arthritis in 24, and inflammatory arthritis in 17 patients. There were 21 index, 27 middle, 18 ring, and 10 small fingers. The average number of reoperations per PIP joint was 1.6 (range, 1-4). A total of 45 joints had 1 reoperation, 19 had 2, 11 had 3, and 1 had 4. Extensor mechanism dysfunction was the most common reason for reoperation; it involved 51 of 76 fingers and was associated with Chamay or tendon-reflecting surgical approaches. Additional etiologies included component loosening in 17, collateral ligament failure in 10, and volar plate contracture in 8 cases. Inflammatory arthritis was associated with collateral ligament failure. Six fingers were eventually amputated, 9 had PIP joint arthrodeses, and 2 had resection arthroplasties. The arthrodesis and amputation rates correlated with the increased number of reoperations per finger. Clinically, most patients had no or mild pain at the most recent follow-up, and the PIP joint range-of-motion was not significantly different from preoperative values. Pain levels improved with longer follow-up. Reoperations following primary nonconstrained PIP joint arthroplasties are common. Extensor mechanism dysfunction was the most common reason for reoperation. The average reoperation rate was 1.6, and arthrodesis and amputation are associated with an increasing number of operations. Overall clinical outcomes demonstrated no significant change in range of motion, and most patients had mild or no pain. Copyright © 2011 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Losing dexterity: patterns of impaired coordination of finger movements in musician’s dystonia

PubMed Central

Furuya, Shinichi; Tominaga, Kenta; Miyazaki, Fumio; Altenmüller, Eckart

2015-01-01

Extensive training can bring about highly-skilled action, but may also impair motor dexterity by producing involuntary movements and muscular cramping, as seen in focal dystonia (FD) and tremor. To elucidate the underlying neuroplastic mechanisms of FD, the present study addressed the organization of finger movements during piano performance in pianists suffering from the condition. Principal component (PC) analysis identified three patterns of fundamental joint coordination constituting finger movements in both patients and controls. The first two coordination patterns described less individuated movements between the “dystonic” finger and key-striking fingers for patients compared to controls. The third coordination pattern, representing the individuation of movements between the middle and ring fingers, was evident during a sequence of strikes with these fingers in controls, which was absent in the patients. Consequently, rhythmic variability of keystrokes was more pronounced during this sequence of strikes for the patients. A stepwise multiple-regression analysis further identified greater variability of keystrokes for individuals displaying less individuated movements between the affected and striking fingers. The findings suggest that FD alters dexterous joint coordination so as to lower independent control of finger movements, and thereby degrades fine motor control. PMID:26289433

A computational method for comparing the behavior and possible failure of prosthetic implants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nielsen, C.; Hollerbach, K.; Perfect, S.

1995-05-01

Prosthetic joint implants currently in use exhibit high Realistic computer modeling of prosthetic implants provides an opportunity for orthopedic biomechanics researchers and physicians to understand possible in vivo failure modes, without having to resort to lengthy and costly clinical trials. The research presented here is part of a larger effort to develop realistic models of implanted joint prostheses. The example used here is the thumb carpo-metacarpal (cmc) joint. The work, however, can be applied to any other human joints for which prosthetic implants have been designed. Preliminary results of prosthetic joint loading, without surrounding human tissue (i.e., simulating conditions undermore » which the prosthetic joint has not yet been implanted into the human joint), are presented, based on a three-dimensional, nonlinear finite element analysis of three different joint implant designs.« less

Use of the shape memory polymer polystyrene in the creation of thin film stretchable sensors for wearable applications

NASA Astrophysics Data System (ADS)

Van Volkinburg, Kyle R.; Nguyen, Thao; Pegan, Jonathan D.; Khine, Michelle; Washington, Gregory N.

2016-04-01

The shape memory polymer polystyrene (PS) has been used to create complex hierarchical wrinkling in the fabrication of stretchable thin film bimetallic sensors ideal for wearable based gesture monitoring applications. The film has been bonded to the elastomer polydimethylsiloxane (PDMS) and operates as a strain gauge under the general notion of geometric piezoresistivity. The film was subject to tensile, cyclic, and step loading conditions in order to characterize its dynamic behavior. To measure the joint angle of the metacarpophalangeal (MCP) joint on the right index finger, the sensor was adhered to a fitted golf glove above said joint and a motion study was conducted. At maximum joint angle the sensor experienced roughly 23.5% strain. From the study it was found that two simple curves, one while the finger was in flexion and the other while the finger was in extension, were able to predict the joint angle from measured voltage with an average error of 2.99 degrees.

Exploration of Hand Grasp Patterns Elicitable Through Non-Invasive Proximal Nerve Stimulation.

PubMed

Shin, Henry; Watkins, Zach; Hu, Xiaogang

2017-11-29

Various neurological conditions, such as stroke or spinal cord injury, result in an impaired control of the hand. One method of restoring this impairment is through functional electrical stimulation (FES). However, traditional FES techniques often lead to quick fatigue and unnatural ballistic movements. In this study, we sought to explore the capabilities of a non-invasive proximal nerve stimulation technique in eliciting various hand grasp patterns. The ulnar and median nerves proximal to the elbow joint were activated transcutanously using a programmable stimulator, and the resultant finger flexion joint angles were recorded using a motion capture system. The individual finger motions averaged across the three joints were analyzed using a cluster analysis, in order to classify the different hand grasp patterns. With low current intensity (<5 mA and 100 µs pulse width) stimulation, our results show that all of our subjects demonstrated a variety of consistent hand grasp patterns including single finger movement and coordinated multi-finger movements. This study provides initial evidence on the feasibility of a proximal nerve stimulation technique in controlling a variety of finger movements and grasp patterns. Our approach could also be developed into a rehabilitative/assistive tool that can result in flexible movements of the fingers.

Compact Telerobot Hand

NASA Technical Reports Server (NTRS)

Rosheim, Mark; Trechsel, Hans

1993-01-01

Anthropomorphic telerobotic hand contains actuators, joints, sensors, and complex wiring harnesses. Glove protects interior components of hand from dirt and damage. Imitates motions of human fingers and wrist in lifelike and dexterous way. Incorporates pitch/yaw joints in wrist and head knuckles. Hand modular; so fingers removable, interchangeable units. Feature simplifies servicing and maintenance, which must be done frequently in such complex mechanism.

A Soft Sensor-Based Three-Dimensional (3-D) Finger Motion Measurement System

PubMed Central

Park, Wookeun; Ro, Kyongkwan; Kim, Suin; Bae, Joonbum

2017-01-01

In this study, a soft sensor-based three-dimensional (3-D) finger motion measurement system is proposed. The sensors, made of the soft material Ecoflex, comprise embedded microchannels filled with a conductive liquid metal (EGaln). The superior elasticity, light weight, and sensitivity of soft sensors allows them to be embedded in environments in which conventional sensors cannot. Complicated finger joints, such as the carpometacarpal (CMC) joint of the thumb are modeled to specify the location of the sensors. Algorithms to decouple the signals from soft sensors are proposed to extract the pure flexion, extension, abduction, and adduction joint angles. The performance of the proposed system and algorithms are verified by comparison with a camera-based motion capture system. PMID:28241414

Rotational stability test for the diagnosis of radial collateral ligament rupture in the fingers: Anatomical study.

PubMed

Lazarus, P; Hidalgo Diaz, J J; Prunières, G; Pire, E; Taleb, C; Honecker, S; Bellemère, P; Fontaine, C; Liverneaux, P A

2017-04-01

Diagnosing rupture of the radial collateral ligament (RCL) of the finger metacarpophalangeal (MCP) joints is difficult. The aim of this cadaver study was to validate a rotational test for the MCP after RCL transection. With the MCP and proximal interphalangeal joints in flexion, rotation along the axis of the proximal phalanx was applied through an extended distal interphalangeal joint to 36 cadaver fingers. Each finger's pulp described an arc of pronation and supination that was noted on the palm. The test was repeated three times: before transection, after transection of the proper collateral ligament (CL) and after transection of both the proper and accessory CLs. Rotational arcs were measured in pronation and supination. Mean length of the pronation arc after transection of the main RCL was 17.53mm, while it was only 12.41mm before transection for the supination arc. Mean length of the pronation arc after transection of both CLs was 22.83mm compared to only 11.93mm before transection. Our results show a significant difference in pronation stability of the MCP joint after transection of the RCL proper. We can conclude that this rotational stability test is a valid test for diagnosing RCL rupture in MCP joints. Copyright © 2017 SFCM. Published by Elsevier Masson SAS. All rights reserved.

Automatic finger joint synovitis localization in ultrasound images

NASA Astrophysics Data System (ADS)

Nurzynska, Karolina; Smolka, Bogdan

2016-04-01

A long-lasting inflammation of joints results between others in many arthritis diseases. When not cured, it may influence other organs and general patients' health. Therefore, early detection and running proper medical treatment are of big value. The patients' organs are scanned with high frequency acoustic waves, which enable visualization of interior body structures through an ultrasound sonography (USG) image. However, the procedure is standardized, different projections result in a variety of possible data, which should be analyzed in short period of time by a physician, who is using medical atlases as a guidance. This work introduces an efficient framework based on statistical approach to the finger joint USG image, which enables automatic localization of skin and bone regions, which are then used for localization of the finger joint synovitis area. The processing pipeline realizes the task in real-time and proves high accuracy when compared to annotation prepared by the expert.

Evaluation of the Sensitivity and Specificity of the New Clinical Diagnostic and Classification Criteria for Kashin-Beck Disease, an Endemic Osteoarthritis, in China.

PubMed

Yu, Fang Fang; Ping, Zhi Guang; Yao, Chong; Wang, Zhi Wen; Wang, Fu Qi; Guo, Xiong

2017-02-01

This study aimed to evaluate the sensitivity and specificity of the new clinical diagnostic and classification criteria for Kashin-Beck disease (KBD) using six clinical markers: flexion of the distal part of fingers, deformed fingers, enlarged finger joints, shortened fingers, squat down, and dwarfism. One-third of the total population in Linyou County was sampled by stratified random sampling. The survey included baseline characteristics and clinical diagnoses, and the sensitivity and specificity of the new criteria was evaluated. We identified 3,459 KBD patients, of which 69 had early stage KBD, 1,952 had stage I, 1,132 had stage II, and 306 had stage III. A screening test classified enlarged finger joints as stage I KBD, with a sensitivity and specificity of 0.978 and 0.045, respectively. Shortened fingers were classified as stage II KBD, with a sensitivity and specificity of 0.969 and 0.844, respectively, and dwarfism was classified as stage III KBD with a sensitivity and specificity of 0.951 and 0.992, respectively. Serial screening test revealed that the new clinical classification of KBD classified stages I, II, and III KBD with sensitivities of 0.949, 0.945, and 0.925 and specificities of 0.967, 0.970, and 0.993, respectively. The screening tests revealed that enlarged finger joints, shortened fingers, and dwarfism were appropriate markers for the clinical diagnosis and classification of KBD with high sensitivity and specificity. Copyright © 2017 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

The wear of cross-linked polyethylene against itself.

PubMed

Joyce, T J; Ash, H E; Unsworth, A

1996-01-01

Cross-linked polyethylene (XLPE) may have an application as a material for an all-plastic surface replacement finger joint. It is inexpensive, biocompatible and can be injection-moulded into the complex shapes that are found on the ends of the finger bones. Further, the cross-linking of polyethylene has significantly improved its mechanical properties. Therefore, the opportunity exists for an all-XLPE joint, and so the wear characteristics of XLPE sliding against itself have been investigated. Wear tests were carried out on both reciprocating pin-on-plate machines and a finger function simulator. The reciprocating pin-on-plate machines had pins loaded at 10 N and 40 N. All pin-on-plate tests show wear factors from the plates very much greater than those of the pins. After 349 km of sliding, a mean wear factor of 0.46 x 10(-6) mm3/N m was found for the plates compared with 0.021 x 10(-6) mm3/N m for the pins. A fatigue mechanism may be causing this phenomenon of greater plate wear. Tests using the finger function simulator give an average wear rate of 0.22 x 10(-6) mm3/N m after 368 km. This sliding distance is equivalent to 12.5 years of use in vivo. The wear factors found were comparable with those of ultra-high molecular weight polyethylene (UHMWPE) against a metallic counterface and, therefore, as the loads across the finger joint are much less than those across the knee or the hip, it is probable that an all-XLPE finger joint will be viable from a wear point of view.

Reliability of the standard goniometry and diagrammatic recording of finger joint angles: a comparative study with healthy subjects and non-professional raters.

PubMed

Macionis, Valdas

2013-01-09

Diagrammatic recording of finger joint angles by using two criss-crossed paper strips can be a quick substitute to the standard goniometry. As a preliminary step toward clinical validation of the diagrammatic technique, the current study employed healthy subjects and non-professional raters to explore whether reliability estimates of the diagrammatic goniometry are comparable with those of the standard procedure. The study included two procedurally different parts, which were replicated by assigning 24 medical students to act interchangeably as 12 subjects and 12 raters. A larger component of the study was designed to compare goniometers side-by-side in measurement of finger joint angles varying from subject to subject. In the rest of the study, the instruments were compared by parallel evaluations of joint angles similar for all subjects in a situation of simulated change of joint range of motion over time. The subjects used special guides to position the joints of their left ring finger at varying angles of flexion and extension. The obtained diagrams of joint angles were converted to numerical values by computerized measurements. The statistical approaches included calculation of appropriate intraclass correlation coefficients, standard errors of measurements, proportions of measurement differences of 5 or less degrees, and significant differences between paired observations. Reliability estimates were similar for both goniometers. Intra-rater and inter-rater intraclass correlation coefficients ranged from 0.69 to 0.93. The corresponding standard errors of measurements ranged from 2.4 to 4.9 degrees. Repeated measurements of a considerable number of raters fell within clinically non-meaningful 5 degrees of each other in proportions comparable with a criterion value of 0.95. Data collected with both instruments could be similarly interpreted in a simulated situation of change of joint range of motion over time. The paper goniometer and the standard goniometer can be used interchangeably by non-professional raters for evaluation of normal finger joints. The obtained results warrant further research to assess clinical performance of the paper strip technique.

Reliability of the standard goniometry and diagrammatic recording of finger joint angles: a comparative study with healthy subjects and non-professional raters

PubMed Central

2013-01-01

Background Diagrammatic recording of finger joint angles by using two criss-crossed paper strips can be a quick substitute to the standard goniometry. As a preliminary step toward clinical validation of the diagrammatic technique, the current study employed healthy subjects and non-professional raters to explore whether reliability estimates of the diagrammatic goniometry are comparable with those of the standard procedure. Methods The study included two procedurally different parts, which were replicated by assigning 24 medical students to act interchangeably as 12 subjects and 12 raters. A larger component of the study was designed to compare goniometers side-by-side in measurement of finger joint angles varying from subject to subject. In the rest of the study, the instruments were compared by parallel evaluations of joint angles similar for all subjects in a situation of simulated change of joint range of motion over time. The subjects used special guides to position the joints of their left ring finger at varying angles of flexion and extension. The obtained diagrams of joint angles were converted to numerical values by computerized measurements. The statistical approaches included calculation of appropriate intraclass correlation coefficients, standard errors of measurements, proportions of measurement differences of 5 or less degrees, and significant differences between paired observations. Results Reliability estimates were similar for both goniometers. Intra-rater and inter-rater intraclass correlation coefficients ranged from 0.69 to 0.93. The corresponding standard errors of measurements ranged from 2.4 to 4.9 degrees. Repeated measurements of a considerable number of raters fell within clinically non-meaningful 5 degrees of each other in proportions comparable with a criterion value of 0.95. Data collected with both instruments could be similarly interpreted in a simulated situation of change of joint range of motion over time. Conclusions The paper goniometer and the standard goniometer can be used interchangeably by non-professional raters for evaluation of normal finger joints. The obtained results warrant further research to assess clinical performance of the paper strip technique. PMID:23302419

Sacroiliac joint stability: Finite element analysis of implant number, orientation, and superior implant length.

PubMed

Lindsey, Derek P; Kiapour, Ali; Yerby, Scott A; Goel, Vijay K

2018-03-18

To analyze how various implants placement variables affect sacroiliac (SI) joint range of motion. An experimentally validated finite element model of the lumbar spine and pelvis was used to simulate a fusion of the SI joint using various placement configurations of triangular implants (iFuse Implant System ® ). Placement configurations were varied by changing implant orientation, superior implant length, and number of implants. The range of motion of the SI joint was calculated using a constant moment of 10 N-m with a follower load of 400 N. The changes in motion were compared between the treatment groups to assess how the different variables affected the overall motion of the SI joint. Transarticular placement of 3 implants with superior implants that end in the middle of the sacrum resulted in the greatest reduction in range of motion (flexion/extension = 73%, lateral bending = 42%, axial rotation = 72%). The range of motions of the SI joints were reduced with use of transarticular orientation (9%-18%) when compared with an inline orientation. The use of a superior implant that ended mid-sacrum resulted in median reductions of (8%-14%) when compared with a superior implant that ended in the middle of the ala. Reducing the number of implants, resulted in increased SI joint range of motions for the 1 and 2 implant models of 29%-133% and 2%-39%, respectively, when compared with the 3 implant model. Using a validated finite element model we demonstrated that placement of 3 implants across the SI joint using a transarticular orientation with superior implant reaching the sacral midline resulted in the most stable construct. Additional clinical studies may be required to confirm these results.

Sacroiliac joint stability: Finite element analysis of implant number, orientation, and superior implant length

PubMed Central

Lindsey, Derek P; Kiapour, Ali; Yerby, Scott A; Goel, Vijay K

2018-01-01

AIM To analyze how various implants placement variables affect sacroiliac (SI) joint range of motion. METHODS An experimentally validated finite element model of the lumbar spine and pelvis was used to simulate a fusion of the SI joint using various placement configurations of triangular implants (iFuse Implant System®). Placement configurations were varied by changing implant orientation, superior implant length, and number of implants. The range of motion of the SI joint was calculated using a constant moment of 10 N-m with a follower load of 400 N. The changes in motion were compared between the treatment groups to assess how the different variables affected the overall motion of the SI joint. RESULTS Transarticular placement of 3 implants with superior implants that end in the middle of the sacrum resulted in the greatest reduction in range of motion (flexion/extension = 73%, lateral bending = 42%, axial rotation = 72%). The range of motions of the SI joints were reduced with use of transarticular orientation (9%-18%) when compared with an inline orientation. The use of a superior implant that ended mid-sacrum resulted in median reductions of (8%-14%) when compared with a superior implant that ended in the middle of the ala. Reducing the number of implants, resulted in increased SI joint range of motions for the 1 and 2 implant models of 29%-133% and 2%-39%, respectively, when compared with the 3 implant model. CONCLUSION Using a validated finite element model we demonstrated that placement of 3 implants across the SI joint using a transarticular orientation with superior implant reaching the sacral midline resulted in the most stable construct. Additional clinical studies may be required to confirm these results. PMID:29564210

A Prospective Study of Injuries and Injury Risk Factors Among Army Wheel Vehicle Mechanics

DTIC Science & Technology

2006-08-01

metacarpalphalangeal joint and 110* at the proximal interphalangeal joint of the third finger . While keeping the forearm on the padded table surface...ground, then return to the starting point with elbows fully extended. For sit-up, the Soldier bent his knees at a 90’ angle, interlocked his fingers ...Wrist 5 5.4 Hand 2 2.2 Finger 3 3.3 Upper Back 1 1.1 Lower Back Lower Back 16 17.4 Pelvic Area 1 1.1 Anterior Thigh 1 1.1 Knee 17 18.5 Lower Body Calf 1

Speed invariance of independent control of finger movements in pianists

PubMed Central

Soechting, John F.

2012-01-01

Independent control of finger movements characterizes skilled motor behaviors such as tool use and musical performance. The purpose of the present study was to identify the effect of movement frequency (tempo) on individuated finger movements in piano playing. Joint motion at the digits was recorded while 5 expert pianists were playing 30 excerpts from musical pieces with different fingering and key locations either at a predetermined normal tempo or as fast as possible. Principal component analysis and cluster analysis using an expectation-maximization algorithm determined three distinct patterns of finger movement coordination for a keypress with each of the index, middle, ring, and little fingers at each of the two tempi. The finger kinematics of each coordination pattern was overall similar across the tempi. Tone sequences assigned into each cluster were also similar for both tempi. A linear regression analysis determined no apparent difference in the amount of movement covariation between the striking and nonstriking fingers at both metacarpo-phalangeal and proximal-interphalangeal joints across the two tempi, which indicated no effect of tempo on independent finger movements in piano playing. In addition, the standard deviation of interkeystroke interval across strokes did not differ between the two tempi, indicating maintenance of rhythmic accuracy of keystrokes. Strong temporal constraints on finger movements during piano playing may underlie the maintained independent control of fingers over a wider range of tempi, a feature being likely to be specific to skilled pianists. PMID:22815403

Open dislocation of the proximal interphalangeal joint of the little finger subsequent to chronic radial collateral ligament injury: a case report of primary ligament reconstruction with a half-slip of the flexor digitorum superficialis: Case Report.

PubMed

Wada, Kazuma; Hibino, Naohito; Kondo, Kenji; Yoshioka, Shinji; Terai, Tomoya; Henmi, Tatsuhiko; Sairyo, Koichi

2015-01-01

Open dislocation of the proximal interphalangeal (PIP) joint is relatively rare. We report a case of a 32-year-old man who had open dislocation of the PIP joint of the little finger while playing American football. He had a history of chronic radial collateral ligament injury. We reconstructed the radial collateral ligament with a half-slip of the flexor digitorum superficialis tendon.

Associations of work activities requiring pinch or hand grip or exposure to hand-arm vibration with finger and wrist osteoarthritis: a meta-analysis.

PubMed

Hammer, Paula E C; Shiri, Rahman; Kryger, Ann I; Kirkeskov, Lilli; Bonde, Jens Peter

2014-03-01

We systematically reviewed the epidemiologic evidence linking finger and wrist osteoarthritis (OA) with work activities requiring pinch or hand grip or exposure to hand-arm vibration (HAV). PubMed and Embase databases were searched up to June 2013. We selected studies assessing the associations of radiographic diagnosed finger and/or wrist joint OA with work activities involving pinch or hand grip or exposure to HAV. We used specific criteria to evaluate completeness of reporting, potential confounding, and bias. Pooled odds ratios (OR) were computed using random-effects meta-analyses. Of the 19 studies included, 17 were cross-sectional, 1 was a prospective cohort, and 1 a case-control study. The meta-analyses of studies that controlled their estimates for at least age and gender showed the associations of pinch grip work with proximal interphalangeal joint [OR 1.56, 95% confidence interval (95% CI) 1.09-2.23] and the first carpometacarpal joint OA (OR 2.10, 95% CI 1.06-4.17), but not with distal interphalangeal, metacarpalphalangeal, or wrist joints OA. Hand grip work and exposure to HAV were not associated with any finger or wrist OA. Epidemiological studies provide limited evidence that pinch grip may increase the risk of wrist or finger OA, but causal relation cannot be resolved because of cross-sectional designs and inadequate characterization of biomechanical strain to the hand and wrist.

[Treatment of fractures of proximal phalanx of fingers by Eiffel Tower percutaneous pinning method. A review of 45 cases].

PubMed

Chbani, B; Amar, M F; Loudyi, D; Boutayeb, F

2010-04-01

The authors report in the treatment of fractures of the proximal phalanx of the fingers, the use of Eiffel Tower pinning, a relatively simple method, fast and stable, associated to a protection and early rehabilitation. The objective of this method is to offer to the patient a pollici-digital grip. Our study is a retrospective study of 45 patients treated for fractures of the proximal phalanx of the fingers by percutaneous pinning according to Eiffel Tower method. We detail this simple and economic technique and examine the functional and radiological results of this series of patients. The amplitude of the active total motion of the proximal interphalangeal joint is on average 94.16 degrees (78.5 % of the normal active mobility of the proximal interphalangeal joint), and the amplitude of the active total motion of the metacarpo-phalangeal joint is on average 90.05 degrees (75 % of the normal active mobility of the metacarpo-phalangeal joint). Copyright 2010 Elsevier Masson SAS. All rights reserved.

Hybrid Photoacoustic/Ultrasound Tomograph for Real-Time Finger Imaging.

PubMed

Oeri, Milan; Bost, Wolfgang; Sénégond, Nicolas; Tretbar, Steffen; Fournelle, Marc

2017-10-01

We report a target-enclosing, hybrid tomograph with a total of 768 elements based on capacitive micromachined ultrasound transducer technology and providing fast, high-resolution 2-D/3-D photoacoustic and ultrasound tomography tailored to finger imaging. A freely programmable ultrasound beamforming platform sampling data at 80 MHz was developed to realize plane wave transmission under multiple angles. A multiplexing unit enables the connection and control of a large number of elements. Fast image reconstruction is provided by GPU processing. The tomograph is composed of four independent and fully automated movable arc-shaped transducers, allowing imaging of all three finger joints. The system benefits from photoacoustics, yielding high optical contrast and enabling visualization of finger vascularization, and ultrasound provides morphologic information on joints and surrounding tissue. A diode-pumped, Q-switched Nd:YAG laser and an optical parametric oscillator are used to broaden the spectrum of emitted wavelengths to provide multispectral imaging. Custom-made optical fiber bundles enable illumination of the region of interest in the plane of acoustic detection. Precision in positioning of the probe in motion is ensured by use of a motor-driven guide slide. The current position of the probe is encoded by the stage and used to relate ultrasound and photoacoustic signals to the corresponding region of interest of the suspicious finger joint. The system is characterized in phantoms and a healthy human finger in vivo. The results obtained promise to provide new opportunities in finger diagnostics and establish photoacoustic/ultrasound-tomography in medical routine. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Segmentation of hand radiographs using fast marching methods

NASA Astrophysics Data System (ADS)

Chen, Hong; Novak, Carol L.

2006-03-01

Rheumatoid Arthritis is one of the most common chronic diseases. Joint space width in hand radiographs is evaluated to assess joint damage in order to monitor progression of disease and response to treatment. Manual measurement of joint space width is time-consuming and highly prone to inter- and intra-observer variation. We propose a method for automatic extraction of finger bone boundaries using fast marching methods for quantitative evaluation of joint space width. The proposed algorithm includes two stages: location of hand joints followed by extraction of bone boundaries. By setting the propagation speed of the wave front as a function of image intensity values, the fast marching algorithm extracts the skeleton of the hands, in which each branch corresponds to a finger. The finger joint locations are then determined by using the image gradients along the skeletal branches. In order to extract bone boundaries at joints, the gradient magnitudes are utilized for setting the propagation speed, and the gradient phases are used for discriminating the boundaries of adjacent bones. The bone boundaries are detected by searching for the fastest paths from one side of each joint to the other side. Finally, joint space width is computed based on the extracted upper and lower bone boundaries. The algorithm was evaluated on a test set of 8 two-hand radiographs, including images from healthy patients and from patients suffering from arthritis, gout and psoriasis. Using our method, 97% of 208 joints were accurately located and 89% of 416 bone boundaries were correctly extracted.

[Postoperative evaluation of surgically treated cases with temporary silicone implant in temporomandibular joint].

PubMed

Aoyama, Shigeru; Kino, Koji; Shibuya, Toshihisa; Sato, Fumiaki; Kobayashi, Akiko; Yoshitake, Hiroyuki; Haketa, Tadasu; Amamori, Yoko; Ishikawa, Takayuki; Yoshida, Nahoko; Amagasa, Teruo

2003-09-01

We have carried out temporary silicone implants after diskectomies or arthroplasties in temporomandibular joint surgeries to avoid postoperative adhesion and to maintain articular space. We evaluated 19 joints in 15 patients who had received dacron-reinforced silicone implant after silicone sheet removal through follow-up for at least 6 months. The cases included temporomandibular joint disorder (10 joints in 9 patients), psoriatic arthritis (2 joints in 1 patient), ankylosis (4 joints in 3 patients) and synovial chondromatosis (2 joints in 2 patients). On the basis of the criteria of temporomandibular dysfunction for the results, they were classified as bad (4 patients). It is thought that factors other than the implant are related to the bad results in the postoperative evaluation. In this study, lymphadenopathy induced by exfoliated silicone debris could not be confirmed. The temporary silicone implant in the temporomandibular joint was thought to be useful.

The compensatory motion of wrist immobilization on thumb and index finger performance--kinematic analysis and clinical implications.

PubMed

Liu, Chien-Hsiou; Chiang, Hsin-Yu; Chen, Kun-Hung

2015-01-01

Based on the high prevalence of people with problems in the wrist and hand simultaneously, it is of its importance to clarify whether hand joints exert extra motion to compensate for wrist motion while immobilized. This study aimed to measure the compensatory movement of the thumb and index finger when people perform daily activities with an immobilized wrist. Thirty healthy volunteers were recruited in this study. A wrist splint, the Jebsen-Taylor Hand Function Test, and the OptoTrak Certus motion tracking system were used. Seven inter-digit mean joint angles of the index finger and thumb were calculated. Paired sample t-test was used. (1) The compensatory motions were noted in the Metacarpophalangeal and Carpometacarpal joints of the thumb, and the proximal interphalangeal joints of the index finger; (2) The manifestation of compensatory motion was related to type of activity performed except when picking up light and heavy cans. The compensatory motions appeared while the wrist was immobilized and were found to be disadvantageous to the progression of disease. In the future, studies need to be done to understand how to select products with correct ergonomic design to enable people to reap greater benefits from wearing wrist splints.

Jam Injuries of the Finger: Diagnosis and Management of Injuries to the Interphalangeal Joints Across Multiple Sports and Levels of Experience.

PubMed

Carruthers, Katherine H; Skie, Martin; Jain, Margaret

2016-09-01

Jam injuries of the finger are frequently encountered in general orthopaedic and sports medicine practice. The finger joints in particular are very susceptible to traumatic injury, but in the absence of severe deformity, digital trauma is often downplayed in the hopes of a more rapid return to game play. Articles published from 1966 to 2015 were reviewed to capture historical and current views on the presentation, diagnosis, and treatment of jam injuries in athletes. Clinical review. Level 5. Although jam injuries are frequently grouped together, they represent a host of injuries that can be challenging to differentiate. A thorough knowledge of finger joint anatomy and injury mechanism is critical to perform an appropriate examination, establish an accurate diagnosis, and identify a treatment plan for each patient. Every member of the athletic care team must be aware of the spectrum of digital injuries, including the basic signs present on examination, which may indicate the need for more formal workup. Additionally, preventing injury through athlete education is paramount to athletic care. © 2016 The Author(s).

Successful treatment of a guitarist with a finger joint injury using instrument-assisted soft tissue mobilization: a case report

PubMed Central

Terry Loghmani, M.; Bayliss, Amy J.; Clayton, Greg; Gundeck, Evelina

2015-01-01

Finger injuries are common and can greatly affect a musician’s quality of life. A 55-year-old man, who had injured the proximal interphalangeal joint of the left index finger 6 months prior to any intervention, was treated with a manual therapy approach incorporating instrument-assisted soft tissue mobilization (IASTM). Initial examination findings included self-reported pain and functional limitations and physical impairments that significantly impeded his ability to play the acoustic guitar. He was treated once a week for 6 weeks with IASTM, joint mobilization, therapeutic exercise, and ice massage. Additionally, a home exercise program and self-care instructions were provided. The patient gained positive outcomes with improvements in pain (Numerical Pain Rating Scale while playing the guitar: initial 5/10, discharge 1/10) and function (Disability Arm Shoulder Hand Sports-Performing Arts Optional Module: initial 75; discharge 6·25), each reaching a minimum clinically important difference. Importantly, he was able to play the guitar with minimal to no pain as desired. Physical measures also improved, including an immediate gain in finger range of motion with IASTM alone. Manual therapy approaches integrating IASTM may provide an effective conservative treatment strategy for patients with finger/hand conditions in the performing arts and other patient populations. PMID:26952165

iHandRehab: an interactive hand exoskeleton for active and passive rehabilitation.

PubMed

Li, Jiting; Zheng, Ruoyin; Zhang, Yuru; Yao, Jianchu

2011-01-01

This paper presents an interactive exoskeleton device for hand rehabilitation, iHandRehab, which aims to satisfy the essential requirements for both active and passive rehabilitation motions. iHandRehab is comprised of exoskeletons for the thumb and index finger. These exoskeletons are driven by distant actuation modules through a cable/sheath transmission mechanism. The exoskeleton for each finger has 4 degrees of freedom (DOF), providing independent control for all finger joints. The joint motion is accomplished by a parallelogram mechanism so that the joints of the device and their corresponding finger joints have the same angular displacement when they rotate. Thanks to this design, the joint angles can be measured by sensors real time and high level motion control is therefore made very simple without the need of complicated kinematics. The paper also discusses important issues when the device is used by different patients, including its adjustable joint range of motion (ROM) and adjustable range of phalanx length (ROPL). Experimentally collected data show that the achieved ROM is close to that of a healthy hand and the ROPL covers the size of a typical hand, satisfying the size need of regular hand rehabilitation. In order to evaluate the performance when it works as a haptic device in active mode, the equivalent moment of inertia (MOI) of the device is calculated. The results prove that the device has low inertia which is critical in order to obtain good backdrivability. Experimental analysis shows that the influence of friction accounts for a large portion of the driving torque and warrants future investigation. © 2011 IEEE

Prevalence of self-reported finger deformations and occupational risk factors among professional cooks: a cross-sectional study.

PubMed

Nagasu, Miwako; Sakai, Kazuhiro; Kogi, Kazutaka; Ito, Akiyoshi; Feskens, Edith J M; Tomita, Shigeru; Temmyo, Yoshiomi; Ueno, Mitsuo; Miyagi, Shigeji

2011-05-26

Previous studies have pointed out that the school lunch workers in Japan are suffering from work-related disorders including finger deformations. The purpose of this study was to investigate the prevalence of self-reported finger deformations and the association with job-related risk factors. A cross-sectional questionnaire study of 5,719 subjects (response rate: 81%, 982 men and 4,737 women) was undertaken during September 2003 to February 2004. Finger deformations were found among 11.7% of the men and 35.6% of the women studied, with significant differences among sex, age and sex-age groups. For both men and women the pattern of finger deformations across the hand was similar for the right and the left hand. For women, the deformations were found in about 10% of the distal interphalangeal joints of all fingers. Based on multiple logistic regression analyses, the factors female sex, age, the number of cooked lunches per cook and cooking activities were independently associated with the prevalence of finger deformations. High prevalence odds ratios were found for those frequently carrying or using tools by hands such as delivering containers, distributing meals, preparing dishes, washing equipment, cutting and stirring foods. Among the school lunch workers studied, women had a higher prevalence of finger deformations on all joints of both hands. Various cooking tasks were associated with the prevalence of finger deformations. The results suggest that improvements in working conditions are important for preventing work-related disorders such as finger deformations.

Photoacoustic tomography of the human finger: towards the assessment of inflammatory joint diseases

NASA Astrophysics Data System (ADS)

van Es, P.; Biswas, S. K.; Bernelot Moens, H. J.; Steenbergen, W.; Manohar, S.

2015-03-01

Inflammatory arthritis is often manifested in finger joints. The growth of new or withdrawal of old blood vessels can be a sensitive marker for these diseases. Photoacoustic (PA) imaging has great potential in this respect since it allows the sensitive and highly resolved visualization of blood. We systematically investigated PA imaging of finger vasculature in healthy volunteers using a newly developed PA tomographic system. We present the PA results which show excellent detail of the vasculature. Vessels with diameters ranging between 100 μm and 1.5 mm are visible along with details of the skin, including the epidermis and the subpapillary plexus. The focus of all the studies is at the proximal and distal interphalangeal joints, and in the context of ultimately visualizing the inflamed synovial membrane in patients. This work is important in laying the foundation for detailed research into PA imaging of the phalangeal vasculature in patients suffering from rheumatoid arthritis.

[Implant with a mobile or a fixed bearing in unicompartmental knee joint replacemen].

PubMed

Matziolis, G; Tohtz, S; Gengenbach, B; Perka, C

2007-12-01

Although the goal of anatomical and functional joint reconstruction in unicompartmental knee replacement is well defined, no uniform implant design has become established. In particular, the differential indications for implantation of an implant with a mobile or a fixed bearing are still not clear. The long-term results of mobile and with fixed bearings are comparable, but there are significant differences in resulting knee joint kinematics, tribological properties and implant-associated complications. In unicompartmental knee replacement mobile bearings restore the physiological joint kinematics better than fixed implants, although the differences to total knee arthroplasty seem minor. The decoupling of mobile bearings from the tibia implant allows a high level of congruence with the femoral implant, resulting in larger contact areas than with fixed bearings. This fact in combination with the more physiological joint kinematics leads to less wear and a lower incidence of osteolyses with mobile bearings. Disadvantages of mobile bearings are the higher complication and early revision rates resulting from bearing dislocation and impingement syndromes caused by suboptimal implantation technique or instability. Especially in cases with ligamentous pathology fixed bearings involve a lower complication rate. It seems their use can also be beneficial in patients with a low level of activity, as problems related to wear are of minor importance for this subgroup. The data currently available allow differentiations between various indications for implants with mobile or fixed bearings, so that the implants can be matched to the patient and the joint pathology in unicompartmental knee joint replacement.

Physicochemical and microscopic characterization of implant-abutment joints.

PubMed

Lopes, Patricia A; Carreiro, Adriana F P; Nascimento, Rubens M; Vahey, Brendan R; Henriques, Bruno; Souza, Júlio C M

2018-01-01

The purpose of this study was to investigate Morse taper implant-abutment joints by chemical, mechanical, and microscopic analysis. Surfaces of 10 Morse taper implants and the correlated abutments were inspected by field emission gun-scanning electron microscopy (FEG-SEM) before connection. The implant-abutment connections were tightened at 32 Ncm. For microgap evaluation by FEG-SEM, the systems were embedded in epoxy resin and cross-sectioned at a perpendicular plane of the implant-abutment joint. Furthermore, nanoindentation tests and chemical analysis were performed at the implant-abutment joints. Results were statistically analyzed via one-way analysis of variance, with a significance level of P < 0.05. Defects were noticed on different areas of the abutment surfaces. The minimum and maximum size of microgaps ranged from 0.5 μm up to 5.6 μm. Furthermore, defects were detected throughout the implant-abutment joint that can, ultimately, affect the microgap size after connection. Nanoindentation tests revealed a higher hardness (4.2 ± 0.4 GPa) for abutment composed of Ti6Al4V alloy when compared to implant composed of commercially pure Grade 4 titanium (3.2 ± 0.4 GPa). Surface defects produced during the machining of both implants and abutments can increase the size of microgaps and promote a misfit of implant-abutment joints. In addition, the mismatch in mechanical properties between abutment and implant can promote the wear of surfaces, affecting the size of microgaps and consequently the performance of the joints during mastication.

High resolution three-dimensional photoacoustic imaging of human finger joints in vivo

NASA Astrophysics Data System (ADS)

Xi, Lei; Jiang, Huabei

2015-08-01

We present a method for noninvasively imaging the hand joints using a three-dimensional (3D) photoacoustic imaging (PAI) system. This 3D PAI system utilizes cylindrical scanning in data collection and virtual-detector concept in image reconstruction. The maximum lateral and axial resolutions of the PAI system are 70 μm and 240 μm. The cross-sectional photoacoustic images of a healthy joint clearly exhibited major internal structures including phalanx and tendons, which are not available from the current photoacoustic imaging methods. The in vivo PAI results obtained are comparable with the corresponding 3.0 T MRI images of the finger joint. This study suggests that the proposed method has the potential to be used in early detection of joint diseases such as osteoarthritis.

MR imaging of the metacarpophalangeal joints of the fingers: evaluation of 38 patients with chronic joint disability.

PubMed

Theumann, Nicolas H; Pessis, Eric; Lecompte, Martin; Le Viet, Dominique; Valenti, Philippe; Chevrot, Alain; Bittoun, Jacques; Schnyder, Pierre; Resnick, Donald; Drapé, Jean-Luc

2005-04-01

To report the MR imaging findings of painful injured metacarpophalangeal (MCP) joints of the fingers. MR imaging of 39 injured MCP joints in 38 patients was performed after a mean delay of 8.8 months. The MR images were obtained with the fingers in extended and flexed positions using T2-weighted and T1-weighted sequences before and after intravenous injection of a gadolinium compound. Ten patients were treated surgically. Mean clinical follow-up was 1.8 years. Tears of the collateral ligaments were the most common lesion (30/39), most being radial in location. Contrast-enhanced axial T1-weighted images with the MCP joint in a flexed position showed these lesions optimally. Ten tears were partial and 20 were complete. In 13 patients, MR images showed 17 associated lesions including injuries of the extensor hood (10/17), interosseous tendon (3/17), palmar plate (3/17), and an osteochondral lesion (1/17). Sagittal MR images were essential to highlight palmar plate tears. Partial or complete tears of the collateral ligaments are prevalent MR imaging findings in patients with chronic disability resulting from injuries to the MCP joints. Although conservative treatment generally is sufficient for isolated injuries of the collateral ligaments, surgical repair is often required in cases of more extensive injuries. MR imaging may clearly delineate associated lesions of and about the MCP joints.

Customizing Extensor Reconstruction in Vascularized Toe Joint Transfers to Finger Proximal Interphalangeal Joints: A Strategic Approach for Correcting Extensor Lag.

PubMed

Loh, Charles Yuen Yung; Hsu, Chung-Chen; Lin, Cheng-Hung; Chen, Shih-Heng; Lien, Shwu-Huei; Lin, Chih-Hung; Wei, Fu-Chan; Lin, Yu-Te

2017-04-01

Vascularized toe proximal interphalangeal joint transfer allows the restoration of damaged joints. However, extensor lag and poor arc of motion have been reported. The authors present their outcomes of treatment according to a novel reconstructive algorithm that addresses extensor lag and allows for consistent results postoperatively. Vascularized toe joint transfers were performed in a consecutive series of 26 digits in 25 patients. The average age was 30.5 years, with 14 right and 12 left hands. Reconstructed digits included eight index, 10 middle, and eight ring fingers. Simultaneous extensor reconstructions were performed and eight were centralization of lateral bands, five were direct extensor digitorum longus-to-extensor digitorum communis repairs, and 13 were central slip reconstructions. The average length of follow-up was 16.7 months. The average extension lag was 17.9 degrees. The arc of motion was 57.7 degrees (81.7 percent functional use of pretransfer toe proximal interphalangeal joint arc of motion). There was no significant difference in the reconstructed proximal interphalangeal joint arc of motion for the handedness (p = 0.23), recipient digits (p = 0.37), or surgical experience in vascularized toe joint transfer (p = 0.25). The outcomes of different techniques of extensor mechanism reconstruction were similar in terms of extensor lag, arc of motion, and reconstructed finger arc of motion compared with the pretransfer toe proximal interphalangeal joint arc of motion. With this treatment algorithm, consistent outcomes can be produced with minimal extensor lag and maximum use of potential toe proximal interphalangeal joint arc of motion. Therapeutic, IV.

Kinematic performance of a six degree-of-freedom hand model (6DHand) for use in occupational biomechanics.

PubMed

Buczek, Frank L; Sinsel, Erik W; Gloekler, Daniel S; Wimer, Bryan M; Warren, Christopher M; Wu, John Z

2011-06-03

Upper extremity musculoskeletal disorders represent an important health issue across all industry sectors; as such, the need exists to develop models of the hand that provide comprehensive biomechanics during occupational tasks. Previous optical motion capture studies used a single marker on the dorsal aspect of finger joints, allowing calculation of one and two degree-of-freedom (DOF) joint angles; additional algorithms were needed to define joint centers and the palmar surface of fingers. We developed a 6DOF model (6DHand) to obtain unconstrained kinematics of finger segments, modeled as frusta of right circular cones that approximate the palmar surface. To evaluate kinematic performance, twenty subjects gripped a cylindrical handle as a surrogate for a powered hand tool. We hypothesized that accessory motions (metacarpophalangeal pronation/supination; proximal and distal interphalangeal radial/ulnar deviation and pronation/supination; all joint translations) would be small (less than 5° rotations, less than 2mm translations) if segment anatomical reference frames were aligned correctly, and skin movement artifacts were negligible. For the gripping task, 93 of 112 accessory motions were small by our definition, suggesting this 6DOF approach appropriately models joints of the fingers. Metacarpophalangeal supination was larger than expected (approximately 10°), and may be adjusted through local reference frame optimization procedures previously developed for knee kinematics in gait analysis. Proximal translations at the metacarpophalangeal joints (approximately 10mm) were explained by skin movement across the metacarpals, but would not corrupt inverse dynamics calculated for the phalanges. We assessed performance in this study; a more rigorous validation would likely require medical imaging. Published by Elsevier Ltd.

[Treatment of bacterial infection in the interphalangeal joints of the hand].

PubMed

Vorderwinkler, K-P; Mühldorfer, M; Pillukat, T; van Schoonhoven, J

2011-07-01

Radical debridement of joint infection, prevention of further infection-related tissue destruction. Septic arthritis of interphalangeal joints in the thumb and fingers. Extensive soft tissue defects. Severe impairment of blood circulation, finger gangrene. Noncompliance for immobilization or for treatment with external fixator. Arthrotomy and irrigation with isotonic solution. Radical tissue debridement. Joint preservation possible only in the absence of infection-related macroscopic cartilage damage. Otherwise, resection of the articular surfaces and secondary arthrodesis. Insertion of antibiotic-coated devices. Temporary immobilization with external fixator. Inpatient postoperative treatment with 5-day intravenous administration of a second-generation cephalosporine (e.g., Cefuroxim®) followed by 7-10 days oral application. Adaptation of antibiotics according to antibiogram results. In joint-preserving procedures, radiographs and fixator removal after 4 weeks, active joint mobilization. If joint surfaces were resected, removal of fixator after 6 weeks; arthrodesis under 3-day intravenous broad-band antibiotic prophylaxis. Splint immobilization until consolidation (6-8 weeks). In 10 of 40 patients, the infected joint could be preserved. All infections healed. After an average duration of therapy of 6 (3-11) weeks, 4 individuals were free of complaints, and 6 patients had minor symptoms. Overall range of motion in the affected finger was reduced by 25-50° in 5 patients. All patients could return to work after 6.6 (4-11) weeks. A total of 30 patients were treated with joint resection and external fixator. After 5.6 (4-8) weeks, arthrodesis was performed, leading to consolidation in 29 patients. One patient underwent amputation after 4 months due to delayed gangrene. Treatment duration was 15.7 (7-25) weeks. Eight patients reported no complaints, 14 suffered mild symptoms, 5 had moderate, and 3 had severe symptoms in daily life. In 15 cases, range of motion was diminished by 10-80° in the remaining joints of the affected finger. Patients could return to work after 16.2 (6-28) weeks.

Estimation of Saxophone Control Parameters by Convex Optimization.

PubMed

Wang, Cheng-I; Smyth, Tamara; Lipton, Zachary C

2014-12-01

In this work, an approach to jointly estimating the tone hole configuration (fingering) and reed model parameters of a saxophone is presented. The problem isn't one of merely estimating pitch as one applied fingering can be used to produce several different pitches by bugling or overblowing. Nor can a fingering be estimated solely by the spectral envelope of the produced sound (as it might for estimation of vocal tract shape in speech) since one fingering can produce markedly different spectral envelopes depending on the player's embouchure and control of the reed. The problem is therefore addressed by jointly estimating both the reed (source) parameters and the fingering (filter) of a saxophone model using convex optimization and 1) a bank of filter frequency responses derived from measurement of the saxophone configured with all possible fingerings and 2) sample recordings of notes produced using all possible fingerings, played with different overblowing, dynamics and timbre. The saxophone model couples one of several possible frequency response pairs (corresponding to the applied fingering), and a quasi-static reed model generating input pressure at the mouthpiece, with control parameters being blowing pressure and reed stiffness. Applied fingering and reed parameters are estimated for a given recording by formalizing a minimization problem, where the cost function is the error between the recording and the synthesized sound produced by the model having incremental parameter values for blowing pressure and reed stiffness. The minimization problem is nonlinear and not differentiable and is made solvable using convex optimization. The performance of the fingering identification is evaluated with better accuracy than previous reported value.

Smart material joint band

NASA Astrophysics Data System (ADS)

Tucchio, Michael A.; Stoodt, Robert A.; Livsey, Robert A.

1994-11-01

The present invention relates to an improved connector for joining two tubular members together. The connector is formed by a plurality of longitudinally extending fingers extending from an end of one of tubular members and at least one locking groove in the other of the tubular members for receiving the fingers. The connector further includes a circumferentially extending wire member which is received in a notch in a head portion of each of the plurality of fingers. The wire member is preferably formed from a shape memory alloy and has an original circumference less than the circumference of a circle formed by the notches in a head portions of the fingers. The connector includes apertures through which electric wires may be connected to the shape memory alloy ring member so as to cause the shape memory alloy ring member to return to its original shape and allow release of the joint connection.

Smart material joint band

NASA Astrophysics Data System (ADS)

Tucchio, Michael A.; Stoodt, Robert A.; Livsey, Robert A.

1993-12-01

The present invention relates to an improved connector for joining two tubular members together. The connector is formed by a plurality of longitudinally extending fingers extending from an end of one of the tubular members and at least one locking groove in the other of the tubular members for receiving the fingers. The connector further includes a circumferentially extending wire member which is received in a notch in a head portion of each of the plurality of fingers. The wire member is preferably formed from a shape memory alloy and has an original circumference less than the circumference of a circle formed by the notches in the head portions of the fingers. The connector includes apertures through which electric wires may be connected to the shape memory alloy ring member so as to cause the shape memory alloy ring member to return to its original shape and allow release of the joint connection.

The Power of a Soccer Ball: A Traumatic Open Finger Dislocation-A Rare Case Presentation.

PubMed

Dülgeroğlu, Turan Cihan; Metineren, Hasan; Aydın, Ekrem; Dülgeroğlu, Ayşegül

2015-01-01

Proximal interphalangeal joint dislocations are injuries observed frequently and caused by axial loading on the finger in the extension. In this paper we present a traumatic open finger dislocation due to a ball hitting a wrestler. It was successfully treated with reduction and the volar plate and collateral bond fixation were applied with absorbable sutures.

Man-equivalent telepresence through four fingered human-like hand system

NASA Technical Reports Server (NTRS)

Jau, Bruno M.

1992-01-01

The author describes a newly developed mechanical hand system. The robot hand is in human-like configuration with a thumb and three fingers, a palm, a wrist, and the forearm in which the hand and wrist actuators are located. Each finger and the wrist has its own active electromechanical compliance system, allowing the joint drive trains to be stiffened or loosened. This mechanism imitates the human muscle dual function of positioner and stiffness controller. This is essential for soft grappling operations. The hand-wrist assembly has 16 finger joints, three wrist joints, and five compliance mechanisms for a total of 24 degrees of freedom. The strength of the hand is roughly half that of the human hand and its size is comparable to a male hand. The hand is controlled through an exoskeleton glove controller that the operator wears. The glove provides the man-machine interface in telemanipulation control mode: it senses the operator's inputs to guide the mechanical hand in hybrid position and force control. The hand system is intended for dexterous manipulations in structured environments. Typical applications will include work in hostile environment such as space operations and nuclear power plants.

Computer-aided classification of optical images for diagnosis of osteoarthritis in the finger joints.

PubMed

Zhang, Jiang; Wang, James Z; Yuan, Zhen; Sobel, Eric S; Jiang, Huabei

2011-01-01

This study presents a computer-aided classification method to distinguish osteoarthritis finger joints from healthy ones based on the functional images captured by x-ray guided diffuse optical tomography. Three imaging features, joint space width, optical absorption, and scattering coefficients, are employed to train a Least Squares Support Vector Machine (LS-SVM) classifier for osteoarthritis classification. The 10-fold validation results show that all osteoarthritis joints are clearly identified and all healthy joints are ruled out by the LS-SVM classifier. The best sensitivity, specificity, and overall accuracy of the classification by experienced technicians based on manual calculation of optical properties and visual examination of optical images are only 85%, 93%, and 90%, respectively. Therefore, our LS-SVM based computer-aided classification is a considerably improved method for osteoarthritis diagnosis.

Biomechanical validation of finite element models for two silicone metacarpophalangeal joint implants.

PubMed

Hussein, A I; Stranart, J C; Meguid, S A; Bogoch, E R

2011-02-01

Silicone implants are used for prosthetic arthroplasty of metacarpophalangeal (MCP) joints severely damaged by rheumatoid arthritis. Different silicone elastomer MCP implant designs have been developed, including the Swanson and the NeuFlex implants. The goal of this study was to compare the in vitro mechanical behavior of Swanson and NeuFlex MCP joint implants. Three-dimensional (3D) finite element (FE) models of the silicone implants were modeled using the commercial software ANSYS and subjected to angular displacement from 0 deg to 90 deg. FE models were validated using mechanical tests of implants incrementally bent from 0 deg to 90 deg in a joint simulator. Swanson size 2 and 4 implants were compared with NeuFlex size 10 and 30 implants, respectively. Good agreement was observed throughout the range of motion for the flexion bending moment derived from 3D FE models and mechanical tests. From 30 deg to 90 deg, the Swanson 2 demonstrated a greater resistance to deformation than the NeuFlex 10 and required a greater bending moment for joint flexion. For larger implant sizes, the NeuFlex 30 had a steeper moment-displacement curve, but required a lower moment than the Swanson 4, due to implant preflexion. On average, the stress generated at the implant hinge from 30 deg to 90 deg was lower in the NeuFlex than in the Swanson. On average, starting from the neutral position of 30 deg for the preflexed NeuFlex implant, higher moments were required to extend the NeuFlex implants to 0 deg compared with the Swanson implants, which returned spontaneously to resting position. Implant toggling within the medullary canals was less in the NeuFlex than in the Swanson. The differential performance of these implants may be useful in implant selection based on the preoperative condition(s) of the joint and specific patient functional needs.

A Biomechanical Simulation of the Effect of the Extrinsic Flexor Muscles on Finger Joint Flexion

DTIC Science & Technology

2001-10-25

vol. 44, pp. 493-504, 1997. [8] A.B. Leger and T.E. Milner, “The effect of eccentric exercise on intrinsic and reflex stiffness in the human hand...line of action of the tendons and the effective moment arms. After a certain point, the FDP tendon became slack, while the FDS tendon remained...link chain with three revolute joints and four links was created to model the index finger. The tendons from the extrinsic flexor muscles were

On the complexity of classical guitar playing: functional adaptations to task constraints.

PubMed

Heijink, Hank; Meulenbroek, Ruud G J

2002-12-01

The authors performed a behavioral study of the complexity of left-hand finger movements in classical guitar playing. Six professional guitarists played movement sequences in a fixed tempo. Left-hand finger movements were recorded in 3 dimensions, and the guitar sound was recorded synchronously. Assuming that performers prefer to avoid extreme joint angles when moving, the authors hypothesized 3 complexity factors. The results showed differential effects of the complexity factors on the performance measures and on participants' judgments of complexity. The results demonstrated that keeping the joints in the middle of their range is an important principle in guitar playing, and players exploit the available tolerance in timing and placement of the left-hand fingers to control the acoustic output variability.

Determination of representative dimension parameter values of Korean knee joints for knee joint implant design.

PubMed

Kwak, Dai Soon; Tao, Quang Bang; Todo, Mitsugu; Jeon, Insu

2012-05-01

Knee joint implants developed by western companies have been imported to Korea and used for Korean patients. However, many clinical problems occur in knee joints of Korean patients after total knee joint replacement owing to the geometric mismatch between the western implants and Korean knee joint structures. To solve these problems, a method to determine the representative dimension parameter values of Korean knee joints is introduced to aid in the design of knee joint implants appropriate for Korean patients. Measurements of the dimension parameters of 88 male Korean knee joint subjects were carried out. The distribution of the subjects versus each measured parameter value was investigated. The measured dimension parameter values of each parameter were grouped by suitable intervals called the "size group," and average values of the size groups were calculated. The knee joint subjects were grouped as the "patient group" based on "size group numbers" of each parameter. From the iterative calculations to decrease the errors between the average dimension parameter values of each "patient group" and the dimension parameter values of the subjects, the average dimension parameter values that give less than the error criterion were determined to be the representative dimension parameter values for designing knee joint implants for Korean patients.

[Fractures of the proximal interphalangeal joint: Diagnostic and operative therapy options].

PubMed

Unglaub, F; Langer, M F; Hahn, P; Müller, L P; Ahrens, C; Spies, C K

2016-02-01

Joint fractures of the fingers often entail operative interventions in contrast to extra-articular fractures. These types of fracture are inclined to dislocate in addition to the actual fracture. The proximal interphalangeal (PIP) joint in particular often shows comminuted fractures due to the long leverage of the finger and a relatively small diameter of the joint. The clinical examination, X-ray diagnostics and if necessary computed tomography allow the classification into stable and unstable fractures. Unstable fractures must be treated by surgical reduction and fixation. A multitude of operative techniques are available for these mostly complicated fractures. The foremost goal is a stable osteosynthesis of the fracture with repositioning of the dislocation, which enables early physiotherapy in order to prevent tendon adhesion and contracture. This article presents the different types of PIP joint fractures, their specific surgical treatment and postoperative treatment regimens.

Experiments and kinematics analysis of a hand rehabilitation exoskeleton with circuitous joints.

PubMed

Zhang, Fuhai; Fu, Yili; Zhang, Qinchao; Wang, Shuguo

2015-01-01

Aiming at the hand rehabilitation of stroke patients, a wearable hand exoskeleton with circuitous joint is proposed. The circuitous joint adopts the symmetric pinion and rack mechanism (SPRM) with the parallel mechanism. The exoskeleton finger is a serial mechanism composed of three closed-chain SPRM joints in series. The kinematic equations of the open chain of the finger and the closed chains of the SPRM joints were built to analyze the kinematics of the hand rehabilitation exoskeleton. The experimental setup of the hand rehabilitation exoskeleton was built and the continuous passive motion (CPM) rehabilitation experiment and the test of human-robot interaction force measurement were conducted. Experiment results show that the mechanical design of the hand rehabilitation robot is reasonable and that the kinematic analysis is correct, thus the exoskeleton can be used for the hand rehabilitation of stroke patients.

[Plantar fibromatosis and Dupuytren's contracture in an adolescent].

PubMed

Nikolić, Jelena; Janjić, Zlata; Momcilović, Dragan; Ninković, Srdjan; Harhai, Vladimir

2011-10-01

Fibromatosis represents a wide group of benign, locally proliferative disorders of fibroblasts. Dupuytren's disease is a benign proliferative disease of palmar aponeurosis which usually affects adults between 40 and 60 years of age. Ledderhose's disease or plantar fibromatosis is plantar equivalent of Dupuyten's disease most often affecting middle-aged and older men, usually bilateral, represented with painless nodule in the medial division of plantar fascia. We presented a 19-year old adolescent that turned to a plastic surgeon complaining to his small finger contracture. He noticed palmar thickening with nodule over the metacarpophalangeal joint of small finger of his right hand when he was 16 years old. A year later a finger started to band. During physical checkup we noticed plantar nodule that also had his father and grandmother. Magnetic resonance and tumor biopsy confirmed a suspicion on plantar fibromatosis - Ledderhose's disease. Clinical exam of the hand clearly led to a conclusion that the patient had Dupuytren's contracture with pretendinous cord over the small finger flexor tendons and lack of extension of proximal interphalangeal (PIP) joint. On the extensor side of the PIP joints there were Garrod's nodes. The patient refused surgical treatment of plantar tumor, but agreed to surgical correction of finger contracture. Despite the fact that Dupuytren's disease and plantar fibromatosis are diseases of adults, the possibility of conjoint appearance of these forms of fibromatosis in adolescent period of life should be kept in mind especially in patients with strong genetic predisposition.

Lack of Hypertonia in Thumb Muscles After Stroke

PubMed Central

Kamper, Derek G.; Rymer, William Z.

2010-01-01

Despite the importance of the thumb to hand function, little is known about the origins of thumb impairment poststroke. Accordingly, the primary purpose of this study was to assess whether thumb flexors have heightened stretch reflexes (SRs) following stroke-induced hand impairment. The secondary purpose was to compare SR characteristics of thumb flexors in relation to those of finger flexors since it is unclear whether SR properties of both muscle groups are similarly affected poststroke. Stretch reflexes in thumb and finger flexors were assessed at rest on the paretic side in each of 12 individuals with chronic, severe, stroke-induced hand impairment and in the dominant thumb in each of eight control subjects also at rest. Muscle activity and passive joint flexion torques were measured during imposed slow (SS) and fast stretches (FS) of the flexors that span the metacarpophalangeal joints. Putative spasticity was then quantified in terms of the peak difference between FS and SS joint torques and electromyographic changes. For both the hemiparetic and control groups, the mean normalized peak torque differences (PTDs) measured in thumb flexors were statistically indistinguishable (P = 0.57). In both groups, flexor muscles were primarily unresponsive to rapid stretching. For 10 of 12 hemiparetic subjects, PTDs in thumb flexors were less than those in finger flexors (P = 0.03). Paretic finger flexor muscle reflex activity was consistently elicited during rapid stretching. These results may reflect an important difference between thumb and finger flexors relating to properties of the involved muscle afferents and spinal motoneurons. PMID:20668270

The 3-D vision system integrated dexterous hand

NASA Technical Reports Server (NTRS)

Luo, Ren C.; Han, Youn-Sik

1989-01-01

Most multifingered hands use a tendon mechanism to minimize the size and weight of the hand. Such tendon mechanisms suffer from the problems of striction and friction of the tendons resulting in a reduction of control accuracy. A design for a 3-D vision system integrated dexterous hand with motor control is described which overcomes these problems. The proposed hand is composed of three three-jointed grasping fingers with tactile sensors on their tips, a two-jointed eye finger with a cross-shaped laser beam emitting diode in its distal part. The two non-grasping fingers allow 3-D vision capability and can rotate around the hand to see and measure the sides of grasped objects and the task environment. An algorithm that determines the range and local orientation of the contact surface using a cross-shaped laser beam is introduced along with some potential applications. An efficient method for finger force calculation is presented which uses the measured contact surface normals of an object.

Design and control of a hand exoskeleton for use in extravehicular activities

NASA Technical Reports Server (NTRS)

Shields, B.; Peterson, S.; Strauss, A.; Main, J.

1993-01-01

To counter problems inherent in extravehicular activities (EVA) and complex space operations, an exoskeleton, a unique adaptive structure, has been designed. The exoskeleton fits on the hand and powers the proximal and middle phalanges of the index finger, the middle finger, and the combined ring and little finger. A kinematic analysis of the exoskeleton joints was performed using the loop-closure method. This analysis determined the angular displacement and velocity relationships of the exoskeleton joints. This information was used to determine the output power of the exoskeleton. Three small DC motors (one for each finger) are used to power the exoskeleton. The motors are mounted on the forearm. Power is transferred to the exoskeleton using lead screws. The control system for the exoskeleton measures the contact force between the operator and the exoskeleton. This information is used as the input to drive the actuation system. The control system allows the motor to rotate in both directions so that the operator may close or open the exoskeleton.

[Microcirculatory investigations in hemophilia patients].

PubMed

Davydkin, I L; Kosiakova, Iu A

2012-01-01

to evaluate microcirculation (MC) and its influencing factors in hemophilia patients. In 44 hemophilia patients with recurrent hemarthrosis, laser Doppler flowmetry was used to evaluate resting MC above the index fingers, knee and ankle joints during an occlusion test, with allowance made for muscle and adipose tissue mass. The increased perfusion value above the afflicted joints was found to correspond to the phase of an exacerbation of posthemorrhagic inflammation and to be a risk factor of recurrent hemarrthrosis. Analysis of the occlusion test above the knee joints and index fingers revealed a diminished MC reserve and a tendency to precapillary spasm. MC changes were more pronounced in a shortage of muscle and adipose tissue mass. Hemophilia patients must regularly do physical exercises to make skeletal muscles develop well in order to prevent an exacerbation of the joint inflammatory process.

Tomosynthesis can facilitate accurate measurement of joint space width under the condition of the oblique incidence of X-rays in patients with rheumatoid arthritis.

PubMed

Ono, Yohei; Kashihara, Rina; Yasojima, Nobutoshi; Kasahara, Hideki; Shimizu, Yuka; Tamura, Kenichi; Tsutsumi, Kaori; Sutherland, Kenneth; Koike, Takao; Kamishima, Tamotsu

2016-06-01

Accurate evaluation of joint space width (JSW) is important in the assessment of rheumatoid arthritis (RA). In clinical radiography of bilateral hands, the oblique incidence of X-rays is unavoidable, which may cause perceptional or measurement error of JSW. The objective of this study was to examine whether tomosynthesis, a recently developed modality, can facilitate a more accurate evaluation of JSW than radiography under the condition of oblique incidence of X-rays. We investigated quantitative errors derived from the oblique incidence of X-rays by imaging phantoms simulating various finger joint spaces using radiographs and tomosynthesis images. We then compared the qualitative results of the modified total Sharp score of a total of 320 joints from 20 patients with RA between these modalities. A quantitative error was prominent when the location of the phantom was shifted along the JSW direction. Modified total Sharp scores of tomosynthesis images were significantly higher than those of radiography, that is to say JSW was regarded as narrower in tomosynthesis than in radiography when finger joints were located where the oblique incidence of X-rays is expected in the JSW direction. Tomosynthesis can facilitate accurate evaluation of JSW in finger joints of patients with RA, even with oblique incidence of X-rays. Accurate evaluation of JSW is necessary for the management of patients with RA. Through phantom and clinical studies, we demonstrate that tomosynthesis may achieve more accurate evaluation of JSW.

Concept for a large master/slave-controlled robotic hand

NASA Technical Reports Server (NTRS)

Grissom, William A.; Abdallah, Mahmoud A.; White, Carl L.

1988-01-01

A strategy is presented for the design and construction of a large master/slave-controlled, five-finger robotic hand. Each of the five fingers will possess four independent axes each driven by a brushless DC servomotor and, thus, four degrees-of-freedom. It is proposed that commercially available components be utilized as much as possible to fabricate a working laboratory model of the device with an anticipated overall length of two-to-four feet (0.6 to 1.2 m). The fingers are to be designed so that proximity, tactile, or force/torque sensors can be imbedded in their structure. In order to provide for the simultaneous control of the twenty independent hand joints, a multilevel master/slave control strategy is proposed in which the operator wears a specially instrumented glove which produces control signals corresponding to the finger configurations and which is capable of conveying sensor feedback signals to the operator. Two dexterous hand master devices are currently commercially available for this application with both undergoing continuing development. A third approach to be investigated for the master control mode is the use of real-time image processing of a specially patterned master glove to provide the respective control signals for positioning the multiple finger joints.

The Dorsal 4-finger Technique: A Novel Method to Examine Metacarpophalangeal Joints in Patients with Rheumatoid Arthritis.

PubMed

Omair, Mohammed A; Akhavan, Pooneh; Naraghi, Ali; Mittoo, Shikha; Xiong, Juan; Weber, Deborah; Lin, Daming; Weber, Melissa; Keystone, Edward C

2018-03-01

To describe the dorsal 4-finger technique (DFFT) in examining metacarpophalangeal (MCP) joints of patients with rheumatoid arthritis (RA) and compare it to the traditional 2-finger technique (TFT) using ultrasound (US) as a gold standard. Four rheumatologists evaluated 180 MCP joints of 18 patients with RA. All patients underwent US for greyscale (GSUS) and power Doppler US (PDUS). Agreements between rheumatologists, the 2 techniques, and US were evaluated using Cohen κ and the first-order agreement coefficient (AC1) κ methods. The population comprised 17 females (94.4%) with a mean (SD) age and disease duration of 56.8 (14.4) and 21.8 (12.9) years, respectively. Eight patients (44.4%) were taking methotrexate monotherapy, while 10 patients (55.6%) were receiving biologics. US evaluation revealed 69 (38.3%) and 30 (16.7%) joints exhibited synovitis grade 2-3 by GSUS and PDUS, respectively. Effusion was documented in 30 joints (16.7%). The mean intraobserver agreement using the DFFT and TFT were 80.5% and 86%, respectively. The mean interobserver agreements using the DFFT and TFT were 84% and 74%, respectively. κ agreement with US findings was similar for both techniques in tender joints but was higher for the DFFT in nontender joints (0.33 vs 0.07, p = 0.015 for GSUS) and (0.48 vs 0.11, p = 0.002 for PDUS). The DFFT had a higher sensitivity in detecting ballottement by GSUS (0.47 vs 0.2, p < 0.001) and PDUS (0.60 vs 0.27, p < 0.001). The DFFT is a novel, reproducible, and reliable method to examine MCP joints, and it has a better correlation with US than the traditional TFT.

Sliding Window-Based Region of Interest Extraction for Finger Vein Images

PubMed Central

Yang, Lu; Yang, Gongping; Yin, Yilong; Xiao, Rongyang

2013-01-01

Region of Interest (ROI) extraction is a crucial step in an automatic finger vein recognition system. The aim of ROI extraction is to decide which part of the image is suitable for finger vein feature extraction. This paper proposes a finger vein ROI extraction method which is robust to finger displacement and rotation. First, we determine the middle line of the finger, which will be used to correct the image skew. Then, a sliding window is used to detect the phalangeal joints and further to ascertain the height of ROI. Last, for the corrective image with certain height, we will obtain the ROI by using the internal tangents of finger edges as the left and right boundary. The experimental results show that the proposed method can extract ROI more accurately and effectively compared with other methods, and thus improve the performance of finger vein identification system. Besides, to acquire the high quality finger vein image during the capture process, we propose eight criteria for finger vein capture from different aspects and these criteria should be helpful to some extent for finger vein capture. PMID:23507824

Energy harvesting from mouse click of robot finger using piezoelectrics

NASA Astrophysics Data System (ADS)

Cha, Youngsu; Hong, Jin; Lee, Jaemin; Park, Jung-Min; Kim, Keehoon

2017-04-01

In this paper, we investigate the feasibility of energy harvesting from the mouse click motion using a piezoelectric energy transducer. Specifically, we use a robotic finger to realize repeatable mouse click motion. The robotic finger wears a glove with a pocket for including the piezoelectric material as an energy transducer. We propose a model for the energy harvesting system through the inverse kinematic framework of parallel joints in the finger and the electromechanical coupling equations of the piezoelectric material. Experiments are performed to elucidate the effect of the load resistance and the mouse click motion on energy harvesting.

Probability of spacesuit-induced fingernail trauma is associated with hand circumference.

PubMed

Opperman, Roedolph A; Waldie, James M A; Natapoff, Alan; Newman, Dava J; Jones, Jeffrey A

2010-10-01

A significant number of astronauts sustain hand injuries during extravehicular activity training and operations. These hand injuries have been known to cause fingernail delamination (onycholysis) that requires medical intervention. This study investigated correlations between the anthropometrics of the hand and susceptibility to injury. The analysis explored the hypothesis that crewmembers with a high finger-to-hand size ratio are more likely to experience injuries. A database of 232 crewmembers' injury records and anthropometrics was sourced from NASA Johnson Space Center. No significant effect of finger-to-hand size was found on the probability of injury, but circumference and width of the metacarpophalangeal (MCP) joint were found to be significantly associated with injuries by the Kruskal-Wallis test. A multivariate logistic regression showed that hand circumference is the dominant effect on the likelihood of onycholysis. Male crewmembers with a hand circumference > 22.86 cm (9") have a 19.6% probability of finger injury, but those with hand circumferences < or = 22.86 cm (9") only have a 5.6% chance of injury. Findings were similar for female crewmembers. This increased probability may be due to constriction at large MCP joints by the current NASA Phase VI glove. Constriction may lead to occlusion of vascular flow to the fingers that may increase the chances of onycholysis. Injury rates are lower on gloves such as the superseded series 4000 and the Russian Orlan that provide more volume for the MCP joint. This suggests that we can reduce onycholysis by modifying the design of the current gloves at the MCP joint.

Control of multi-joint arm movements for the manipulation of touch in keystroke by expert pianists

PubMed Central

2010-01-01

Background Production of a variety of finger-key touches in the piano is essential for expressive musical performance. However, it remains unknown how expert pianists control multi-joint finger and arm movements for manipulating the touch. The present study investigated differences in kinematics and kinetics of the upper-limb movements while expert pianists were depressing a key with two different touches: pressed and struck. The former starts key-depression with the finger-tip contacting the key, whereas the latter involves preparatory arm-lift before striking the key. To determine the effect of individual muscular torque (MUS) as well as non-muscular torques on joint acceleration, we performed a series of inverse and forward dynamics computations. Results The pressed touch showed smaller elbow extension velocity, and larger shoulder and finger flexion velocities during key-depression compared with the struck touch. The former touch also showed smaller elbow extension acceleration directly attributed to the shoulder MUS. In contrast, the shoulder flexion acceleration induced by elbow and wrist MUS was greater for the pressed touch than the struck touch. Towards the goal of producing the target finger-key contact dynamics, the pressed and struck touches effectively took advantage of the distal-to-proximal and proximal-to-distal inter-segmental dynamics, respectively. Furthermore, a psychoacoustic experiment confirmed that a tone elicited by the pressed touch was perceived softer than that by the struck touch. Conclusion The present findings suggest that manipulation of tone timbre depends on control of inter-segmental dynamics in piano keystroke. PMID:20630085

Single Degree-of-Freedom Exoskeleton Mechanism Design for Finger Rehabilitation

PubMed Central

Wolbrecht, Eric T.; Reinkensmeyer, David J.; Perez-Gracia, Alba

2014-01-01

This paper presents the kinematic design of a single degree-of-freedom exoskeleton mechanism: a planar eight-bar mechanism for finger curling. The mechanism is part of a finger-thumb robotic device for hand therapy that will allow users to practice key pinch grip and finger-thumb opposition, allowing discrete control inputs for playing notes on a musical gaming interface. This approach uses the mechanism to generate the desired grasping trajectory rather than actuating the joints of the fingers and thumb independently. In addition, the mechanism is confined to the back of the hand, so as to allow sensory input into the palm of the hand, minimal size and apparent inertia, and the possibility of placing multiple mechanisms side-by-side to allow control of individual fingers. PMID:22275628

The Manumeter: A non-obtrusive wearable device for monitoring spontaneous use of the wrist and fingers

PubMed Central

Rowe, Justin B.; Friedman, Nizan; Bachman, Mark; Reinkensmeyer, David J.

2014-01-01

This paper describes the design and pilot testing of a novel device for unobtrusive monitoring of wrist and hand movement through a sensorized watch and a magnetic ring system called the manumeter. The device senses the magnetic field of the ring through two triaxial magnetometers and records the data to onboard memory which can be analyzed later by connecting the watch unit to a computer. Wrist and finger joint angles are estimated using a radial basis function network. We compared joint angle estimates collected using the manumeter to direct measurements taken using a passive exoskeleton and found that after a 60 minute trial, 95% of the radial/ulnar deviation, wrist flexion/extension and finger flexion/extension estimates were within 2.4, 5.8, and 4.7 degrees of their actual values respectively. The device measured angular distance traveled for these three joints within 10.4%, 4.5%, and 14.3 % of their actual values. The manumeter has potential to improve monitoring of real world use of the hand after stroke and in other applications. PMID:24187216

The manufacture of generic replicas of implants for arthroplasty of the hip and knee: is it regulated and will it save money?

PubMed

Atrey, A; Heylen, S; Gosling, O; Porteous, M J L; Haddad, F S

2016-07-01

Joint replacement of the hip and knee remain very satisfactory operations. They are, however, expensive. The actual manufacturing of the implant represents only 30% of the final cost, while sales and marketing represent 40%. Recently, the patents on many well established and successful implants have expired. Companies have started producing and distributing implants that purport to replicate existing implants with good long-term results. The aims of this paper are to assess the legality, the monitoring and cost saving implications of such generic implants. We also assess how this might affect the traditional orthopaedic implant companies. Cite this article: Bone Joint J 2016;98-B:892-900. ©2016 The British Editorial Society of Bone & Joint Surgery.

Ball-joint grounding ring

NASA Technical Reports Server (NTRS)

Aperlo, P. J. A.; Buck, P. A.; Weldon, V. A.

1981-01-01

In ball and socket joint where electrical insulator such as polytetrafluoroethylene is used as line to minimize friction, good electrical contact across joint may be needed for lightning protection or to prevent static-charge build-up. Electrical contact is maintained by ring of spring-loaded fingers mounted in socket. It may be useful in industry for cranes, trailers, and other applications requiring ball and socket joint.

Utility of Intraoperative Neuromonitoring during Minimally Invasive Fusion of the Sacroiliac Joint.

PubMed

Woods, Michael; Birkholz, Denise; MacBarb, Regina; Capobianco, Robyn; Woods, Adam

2014-01-01

Study Design. Retrospective case series. Objective. To document the clinical utility of intraoperative neuromonitoring during minimally invasive surgical sacroiliac joint fusion for patients diagnosed with sacroiliac joint dysfunction (as a direct result of sacroiliac joint disruptions or degenerative sacroiliitis) and determine stimulated electromyography thresholds reflective of favorable implant position. Summary of Background Data. Intraoperative neuromonitoring is a well-accepted adjunct to minimally invasive pedicle screw placement. The utility of intraoperative neuromonitoring during minimally invasive surgical sacroiliac joint fusion using a series of triangular, titanium porous plasma coated implants has not been evaluated. Methods. A medical chart review of consecutive patients treated with minimally invasive surgical sacroiliac joint fusion was undertaken at a single center. Baseline patient demographics and medical history, intraoperative electromyography thresholds, and perioperative adverse events were collected after obtaining IRB approval. Results. 111 implants were placed in 37 patients. Sensitivity of EMG was 80% and specificity was 97%. Intraoperative neuromonitoring potentially avoided neurologic sequelae as a result of improper positioning in 7% of implants. Conclusions. The results of this study suggest that intraoperative neuromonitoring may be a useful adjunct to minimally invasive surgical sacroiliac joint fusion in avoiding nerve injury during implant placement.

Joint Replacement (Finger and Wrist Joints)

MedlinePlus

... Lawnmower Safety Snowblower safety Pumpkin Carving Gardening Safety Turkey Carving Removing a Ring Fireworks Safety Español Artritis ... Lawnmower Safety Snowblower safety Pumpkin Carving Gardening Safety Turkey Carving Removing a Ring Fireworks Safety Español Artritis ...

Applied Joint-Space Torque and Stiffness Control of Tendon-Driven Fingers

NASA Technical Reports Server (NTRS)

Abdallah, Muhammad E.; Platt, Robert, Jr.; Wampler, Charles W.; Hargrave, Brian

2010-01-01

Existing tendon-driven fingers have applied force control through independent tension controllers on each tendon, i.e. in the tendon-space. The coupled kinematics of the tendons, however, cause such controllers to exhibit a transient coupling in their response. This problem can be resolved by alternatively framing the controllers in the joint-space of the manipulator. This work presents a joint-space torque control law that demonstrates both a decoupled and significantly faster response than an equivalent tendon-space formulation. The law also demonstrates greater speed and robustness than comparable PI controllers. In addition, a tension distribution algorithm is presented here to allocate forces from the joints to the tendons. It allocates the tensions so that they satisfy both an upper and lower bound, and it does so without requiring linear programming or open-ended iterations. The control law and tension distribution algorithm are implemented on the robotic hand of Robonaut-2.

Variable and Asymmetric Range of Enslaving: Fingers Can Act Independently over Small Range of Flexion

PubMed Central

van den Noort, Josien C.; van Beek, Nathalie; van der Kraan, Thomas; Veeger, DirkJan H. E. J.; Stegeman, Dick F.; Veltink, Peter H.; Maas, Huub

2016-01-01

The variability in the numerous tasks in which we use our hands is very large. However, independent movement control of individual fingers is limited. To assess the extent of finger independency during full-range finger flexion including all finger joints, we studied enslaving (movement in non-instructed fingers) and range of independent finger movement through the whole finger flexion trajectory in single and multi-finger movement tasks. Thirteen young healthy subjects performed single- and multi-finger movement tasks under two conditions: active flexion through the full range of movement with all fingers free to move and active flexion while the non-instructed finger(s) were restrained. Finger kinematics were measured using inertial sensors (PowerGlove), to assess enslaving and range of independent finger movement. Although all fingers showed enslaving movement to some extent, highest enslaving was found in adjacent fingers. Enslaving effects in ring and little finger were increased with movement of additional, non-adjacent fingers. The middle finger was the only finger affected by restriction in movement of non-instructed fingers. Each finger showed a range of independent movement before the non-instructed fingers started to move, which was largest for the index finger. The start of enslaving was asymmetrical for adjacent fingers. Little finger enslaving movement was affected by multi-finger movement. We conclude that no finger can move independently through the full range of finger flexion, although some degree of full independence is present for smaller movements. This range of independent movement is asymmetric and variable between fingers and between subjects. The presented results provide insight into the role of finger independency for different types of tasks and populations. PMID:27992598

Multi-Disciplinary Antimicrobial Strategies for Improving Orthopaedic Implants to Prevent Prosthetic Joint Infections in Hip and Knee

PubMed Central

Getzlaf, Matthew A.; Lewallen, Eric A.; Kremers, Hilal M.; Jones, Dakota L.; Bonin, Carolina A.; Dudakovic, Amel; Thaler, Roman; Cohen, Robert C.; Lewallen, David G.; van Wijnen, Andre J.

2016-01-01

Like any foreign object, orthopaedic implants are susceptible to infection when introduced into the human body. Without additional preventative measures, the absolute number of annual prosthetic joint infections will continue to rise, and may exceed the capacity of health care systems in the near future. Bacteria are difficult to eradicate from synovial joints due to their exceptionally diverse taxonomy, complex mechanistic attachment capabilities, and tendency to evolve antibiotic resistance. When a primary orthopaedic implant fails from prosthetic joint infection, surgeons are generally challenged by limited options for intervention. In this review, we highlight the etiology and taxonomic groupings of bacteria known to cause prosthetic joint infections, and examine their key mechanisms of attachment. We propose that antimicrobial strategies should focus on the most harmful bacteria taxa within the context of occurrence, taxonomic diversity, adhesion mechanisms, and implant design. Patient-specific identification of organisms that cause prosthetic joint infections will permit assessment of their biological vulnerabilities. The latter can be targeted using a range of antimicrobial techniques that exploit different colonization mechanisms including implant surface attachment, biofilm formation, and/or hematogenous recruitment. We anticipate that customized strategies for each patient, joint, and prosthetic component will be most effective at reducing prosthetic joint infections, including those caused by antibiotic-resistant and polymicrobial bacteria. PMID:26449208

Kinematic Origins of Motor Inconsistency in Expert Pianists.

PubMed

Tominaga, Kenta; Lee, André; Altenmüller, Eckart; Miyazaki, Fumio; Furuya, Shinichi

2016-01-01

For top performers, including athletes and musicians, even subtle inconsistencies in rhythm and force during movement production decrease the quality of performance. However, extensive training over many years beginning in childhood is unable to perfect dexterous motor performance so that it is without any error. To gain insight into the biological mechanisms underlying the subtle defects of motor actions, the present study sought to identify the kinematic origins of inconsistency of dexterous finger movements in musical performance. Seven highly-skilled pianists who have won prizes at international piano competitions played a short sequence of tones with the right hand at a predetermined tempo. Time-varying joint angles of the fingers were recorded using a custom-made data glove, and the timing and velocity of the individual keystrokes were recorded from a digital piano. Both ridge and stepwise multiple regression analyses demonstrated an association of the inter-trial variability of the inter-keystroke interval (i.e., rhythmic inconsistency) with both the rotational velocity of joints of the finger used for a keystroke (i.e., striking finger) and the movement independence between the striking and non-striking fingers. This indicates a relationship between rhythmic inconsistency in musical performance and the dynamic features of movements in not only the striking finger but also the non-striking fingers. In contrast, the inter-trial variability of the key-descending velocity (i.e., loudness inconsistency) was associated mostly with the kinematic features of the striking finger at the moment of the keystroke. Furthermore, there was no correlation between the rhythmic and loudness inconsistencies. The results suggest distinct kinematic origins of inconsistencies in rhythm and loudness in expert musical performance.

In vivo electrode implanting system

NASA Technical Reports Server (NTRS)

Collins, Jr., Earl R. (Inventor)

1989-01-01

A cylindrical intramuscular implantable electrode is provided with a strip of fabric secured around it. The fabric is woven from a polyester fiber having loops of the fiber protruding. The end of the main cylindrical body is provided with a blunt conductive nose, and the opposite end is provided with a smaller diameter rear section with an annular groove to receive tips of fingers extending from a release tube. The fingers are formed to spring outwardly and move the fingertips out of the annular groove in order to release the electrode from the release tube when a sheath over the electrode is drawn back sufficiently. The sheath compresses the fingers of the release tube and the fabric loops until it is drawn back. Muscle tissue grows into the loops to secure the electrode in place after the sheath is drawn back. The entire assembly of electrode, release tube and sheath can be inserted into the patient's muscle to the desired position through a hypodermic needle. The release tube may be used to manipulate the electrode in the patient's muscle to an optimum position before the electrode is released.

Extensor Tendon Injuries and Repairs in the Hand

PubMed Central

Kontor, J. A.

1982-01-01

Due to their superficial course, the extensor tendons are frequently lacerated over the dorsum of the hand and fingers. Excellent functional results are obtained in repairs of simple tendon lacerations. ‘Open’ mallet lacerations over the distal IP joint or involving the central extensor slip over the proximal IP joint require more precise suturing methods. More proximal extensor tendon divisions near the wrist involve dissection of the retracted finger extensors or long thumb extensor in the distal forearm and more formal tendon repairs, including a possible tendon transfer to the thumb. ‘Closed injuries’, with varying degrees of extensor tendon disruption, occur at three main sites. The mallet injury at the DIP joint and the boutonnière deformity over the PIP joint are sometimes recognized late, but respond to conservative splinting for a minimum of four weeks with guarded motion avoiding secondary stiffening of the remaining small joints of the hand. Surgery of closed injuries most frequently involves the intra-articular traction fracture type of mallet deformities in which the DIP joint has taken the brunt of the injury. PMID:21286174

Modelling tendon excursions and moment arms of the finger flexors: anatomic fidelity versus function.

PubMed

Kociolek, Aaron M; Keir, Peter J

2011-07-07

A detailed musculoskeletal model of the human hand is needed to investigate the pathomechanics of tendon disorders and carpal tunnel syndrome. The purpose of this study was to develop a biomechanical model with realistic flexor tendon excursions and moment arms. An existing upper extremity model served as a starting point, which included programmed movement of the index finger. Movement capabilities were added for the other fingers. Metacarpophalangeal articulations were modelled as universal joints to simulate flexion/extension and abduction/adduction while interphalangeal articulations used hinges to represent flexion. Flexor tendon paths were modelled using two approaches. The first method constrained tendons with control points, representing annular pulleys. The second technique used wrap objects at the joints as tendon constraints. Both control point and joint wrap models were iteratively adjusted to coincide with tendon excursions and moment arms from a anthropometric regression model using inputs for a 50th percentile male. Tendon excursions from the joint wrap method best matched the regression model even though anatomic features of the tendon paths were not preserved (absolute differences: mean<0.33 mm, peak<0.74 mm). The joint wrap model also produced similar moment arms to the regression (absolute differences: mean<0.63 mm, peak<1.58 mm). When a scaling algorithm was used to test anthropometrics, the scaled joint wrap models better matched the regression than the scaled control point models. Detailed patient-specific anatomical data will improve model outcomes for clinical use; however, population studies may benefit from simplified geometry, especially with anthropometric scaling. Copyright © 2011 Elsevier Ltd. All rights reserved.

The effects of progressive lateralization of the joint center of rotation of reverse total shoulder implants.

PubMed

Costantini, Oren; Choi, Daniel S; Kontaxis, Andreas; Gulotta, Lawrence V

2015-07-01

There has been a renewed interest in lateralizing the center of rotation (CoR) in implants used in reverse shoulder arthroplasty. The aim of this study was to determine the sensitivity of lateralization of the CoR on the glenohumeral joint contact forces, muscle moment arms, torque across the bone-implant interface, and the stability of the implant. A 3-dimensional virtual model was used to investigate how lateralization affects deltoid muscle moment arm and glenohumeral joint contact forces. This model was virtually implanted with 5 progressively lateralized reverse shoulder prostheses. The joint contact loads and deltoid moment arms were calculated for each lateralization over the course of 3 simulated standard humerothoracic motions. Lateralization of the CoR leads to an increase in the overall joint contact forces across the glenosphere. Most of this increased loading occurred through compression, although increases in anterior/posterior and superior/inferior shear were also observed. Moment arms of the deltoid consistently decreased with lateralization. Bending moments at the implant interface increased with lateralization. Progressive lateralization resulted in improved stability ratios. Lateralization results in increased joint loading. Most of that loading occurs through compression, although there were also increases in shear forces. Anterior/posterior shear is currently not accounted for in implant fixation studies, leaving its effect on implant fixation unknown. Future studies should incorporate shear forces into their models to more accurately assess fixation methods. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

The Efficacy and Safety of Concurrent Collagenase Clostridium Histolyticum Injections for 2 Dupuytren Contractures in the Same Hand: A Prospective, Multicenter Study.

PubMed

Gaston, R Glenn; Larsen, Søren Erik; Pess, Gary M; Coleman, Stephen; Dean, Brian; Cohen, Brian M; Kaufman, Gregory J; Tursi, James P; Hurst, Lawrence C

2015-10-01

To evaluate efficacy and safety of concurrent administration of 2 collagenase clostridium histolyticum (CCH) injections to treat 2 joints in the same hand with Dupuytren fixed flexion contractures (FFCs). Patients with 2 or more contractures in the same hand caused by palpable cords participated in a 60-day, multicenter, open-label, phase 3b study. Two 0.58 mg CCH doses were injected into 1 or 2 cords in the same hand (1 injection per affected joint) during the same visit. Finger extension was performed approximately 24, 48, or 72 or more hours later. Changes in FFC and range of motion, incidence of clinical success (FFC ≤ 5°), and adverse events (AEs) were summarized. The study enrolled 715 patients (725 treated joint pairs), and 714 patients (724 joint pairs) were analyzed for efficacy. At day 31, mean total FFC (sum of 2 treated joints) decreased 74%, from 98° to 27°. Mean total range of motion increased from 90° to 156°. The incidence of clinical success was 65% in metacarpophalangeal joints and 29% in proximal interphalangeal joints. Most treatment-related AEs were mild to moderate, resolving without intervention; the most common were swelling of treated extremity, contusion, and pain in extremity. The incidence of skin lacerations was 22% (160 of 715). Efficacy and safety were similar regardless of time to finger extension. Collagenase clostridium histolyticum can be used to effectively treat 2 affected joints concurrently without a greater risk of AEs than treatment of a single joint, with the exception of skin laceration. The incidence of clinical success in this study after 1 injection per joint was comparable to phase 3 study results after 3 or more injections per joint. Two concurrent CCH injections may allow more rapid overall treatment of multiple affected joints, and the ability to vary the time between CCH injection and finger extension may allow physicians and patients greater flexibility with scheduling treatment. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

[Demographic features and difficulties in rehabilitation in patients referred to hand rehabilitation unit for phalangeal fractures].

PubMed

Sahin, Füsun; Yücel, Serap Dalgiç; Yilmaz, Figen; Ergöz, Ernur; Kuran, Banu

2006-01-01

We evaluated demographic and occupational features of patients with phalangeal fractures of the hand, etiologies and types of injuries, and the results of rehabilitation. The study included 91 fingers of 62 patients (54 males, 8 females; mean age 28+/-13 years; range 4 to 59 years) who were referred to our hand rehabilitation unit for phalangeal fractures. Demographic features, the cause and localization of injury, the type of surgery, time from surgery to rehabilitation, and the follow-up period were determined. At the end of rehabilitation, range of motion (ROM) of the phalangeal joint and total ROM of the injured fingers were assessed using the Strickland-Glogovac rating system. A great majority of injuries were caused by work accidents, followed by sport injuries and falls occurring in students. Sixty patients (96.8%) were right-handed. The fractures occurred in the dominant hand in 29 patients (46.8%). The majority of patients (n=45) were primary school graduates. The most common mechanism of injury was accidents related to heavy work machinery (n=18). The most commonly injured finger and the phalanx were the third finger (n=25, 27.5%) and the proximal phalanx (n=59, 56.7%), respectively. Only 27 patients (43.6%) had a sufficient follow-up with a mean of 79.7+/-46.6 days (range 30 to 254 days). Following rehabilitation, the mean ROM and the total ROM were 45.0+/-22.9 degrees and 63.3+/-16.1 degrees for the injured joint and the thumb, and 31.3+/-22.5 degrees and 122+/-60.3 degrees for the injured joint and the other fingers, respectively. Our data provide important insight into appropriate treatment and rehabilitation of phalangeal fractures, in particular, shortcomings in the treatment and follow-up.

Use of a Multivector Mandibular Distractor for Treatment of Pediatric Proximal Interphalangeal Joint Pilon Fractures: A Case-Based Review.

PubMed

Pedreira, Rachel; Cho, Brian H; Geer, Angela; DeJesus, Ramon A

2018-04-01

The difficulties in surgical treatment of pilon fractures of the finger include fragment reconstitution and posthealing stiffness. In adults, external fixation with traction and early active range of motion (AROM)/passive range of motion (PROM) during healing is considered necessary for avoiding joint stiffness and attaining realignment. The authors present a unique approach to pediatric pilon fractures that uses open reduction and multivector external fixation with delayed AROM/PROM. Initial immobilization and significant traction allowed for joint realignment and prevented noncompliance with staged distraction. The authors believe this immobilization leads to a superior outcome because, unlike adults, children tend to avoid stiffness and a larger distraction force allowed for sufficient joint realignment to regain range of motion (ROM). A right-handed 13-year-old boy sustained a right ring finger fracture and presented 12 days later. Radiographs revealed a comminuted Salter-Harris 4 fracture of the middle phalanx. The patient underwent open reduction and placement of multivector external fixation using a pediatric mandibular distractor/fixator. Significant traction was applied to distract the finger to length. Hardware was removed 6 weeks postoperatively and AROM was initiated after splinting. The patient started PROM 8 weeks postoperatively. Strengthening was initiated 2 weeks later. ROM improved and rehabilitation was continued. The patient exhibited nearly equal grip strength 12 weeks postoperatively. At 14 months follow-up, radiographs showed complete healing and joint realignment. There was no deformity or pain and finger length was restored. Management of pediatric pilon fractures is rarely described and presents unique considerations. Early-stage traction and immobilization using a multivector mandibular fixator/distractor is suitable in a child because noncompliance is avoided and there is a decreased risk for stiffness. Combining early immobilization with subsequent-staged AROM, PROM, and strengthening resulted in no loss of ROM and maintained articular symmetry.

Tendon-bone graft for tendinous mallet fingers following failed splinting.

PubMed

Wang, Le; Zhang, Xu; Liu, Ze; Huang, Xiuge; Zhu, Hongwei; Yu, Yadong

2013-12-01

To describe and assess a surgical technique for the treatment of tendinous mallet fingers after failed conservative treatment. From January 2010 to March 2012, 28 tendinous mallet fingers in 28 patients were treated. All patients had greater than 25° extensor lags after 6 to 8 weeks of splinting. Four patients had a second trial of splinting, which also failed. A tendon-bone graft, taken from the extensor carpi radialis brevis and the third metacarpal base, was used for reconstruction. The mean time between the injury and operation was 74 days. The mean preoperative extension lag was 34°. Five patients reported pain in the distal interphalangeal joint. At the final follow-up, patients rated the level of pain on the distal interphalangeal and wrist joints using a visual analog scale. Joint motion was graded with the Crawford criteria. Hand function was assessed with the Disabilities of the Arm, Shoulder, and Hand questionnaire. Patients reported on their satisfaction based on the Michigan Hand Outcomes Questionnaire. Bone healing was achieved in all patients at a mean of 5 weeks. Position of bone graft was maintained until bone healing was evident in all cases. At the mean follow-up period of 15 months, nail deformity was not noted. No patient reported pain on the distal interphalangeal joint or wrist. The mean residual extension lag of the distal interphalangeal joints was 4°. The results showed that 24 digits were excellent and 4 were good based on the Crawford criteria. The Disabilities of the Arm, Shoulder, and Hand scores averaged 1, and 27 patients were satisfied with appearance of the hand. One patient sometimes felt uncomfortable regarding the appearance. A tendon-bone graft is a useful and reliable technique for the treatment of tendinous mallet fingers after failed splinting. Therapeutic IV. Copyright © 2013 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Effect of radial head implant shape on joint contact area and location during static loading.

PubMed

Shannon, Hannah L; Deluce, Simon R; Lalone, Emily A; Willing, Ryan; King, Graham J W; Johnson, James A

2015-04-01

To examine the effect of implant shape on radiocapitellar joint contact area and location in vitro. We used 8 fresh-frozen cadaveric upper extremities. An elbow loading simulator examined joint contact in pronation, neutral rotation, and supination with the elbow at 90° flexion. Muscle tendons were attached to pneumatic actuators to allow for computer-controlled loading to achieve the desired forearm rotation. We performed testing with the native radial head, an axisymmetric implant, a reverse-engineered patient-specific implant, and a population-based quasi-anatomic implant. Implants were inserted using computer navigation. Contact area and location were quantified using a casting technique. We found no significant difference between contact locations for the native radial head and the 3 implants. All of the implants had a contact area lower than the native radial head; however, only the axisymmetric implant was significantly different. There was no significant difference in contact area between implant shapes. The similar contact areas and locations of the 3 implant designs suggest that the shape of the implant may not be important with respect to radiocapitellar joint contact mechanics when placed optimally using computer navigation. Further work is needed to explore the sensitivity of radial head implant malpositioning on articular contact. The lower contact area of the radial head implants relative to the native radial head is similar to previous benchtop studies and is likely the result of the greater stiffness of the implant. Radial head implant shape does not appear to have a pronounced influence on articular contact, and both axisymmetric and anatomic metal designs result in elevated cartilage stress relative to the intact state. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Morse taper dental implants and platform switching: The new paradigm in oral implantology

PubMed Central

Macedo, José Paulo; Pereira, Jorge; Vahey, Brendan R.; Henriques, Bruno; Benfatti, Cesar A. M.; Magini, Ricardo S.; López-López, José; Souza, Júlio C. M.

2016-01-01

The aim of this study was to conduct a literature review on the potential benefits with the use of Morse taper dental implant connections associated with small diameter platform switching abutments. A Medline bibliographical search (from 1961 to 2014) was carried out. The following search items were explored: “Bone loss and platform switching,” “bone loss and implant-abutment joint,” “bone resorption and platform switching,” “bone resorption and implant-abutment joint,” “Morse taper and platform switching.” “Morse taper and implant-abutment joint,” Morse taper and bone resorption,” “crestal bone remodeling and implant-abutment joint,” “crestal bone remodeling and platform switching.” The selection criteria used for the article were: meta-analysis; randomized controlled trials; prospective cohort studies; as well as reviews written in English, Portuguese, or Spanish languages. Within the 287 studies identified, 81 relevant and recent studies were selected. Results indicated a reduced occurrence of peri-implantitis and bone loss at the abutment/implant level associated with Morse taper implants and a reduced-diameter platform switching abutment. Extrapolation of data from previous studies indicates that Morse taper connections associated with platform switching have shown less inflammation and possible bone loss with the peri-implant soft tissues. However, more long-term studies are needed to confirm these trends. PMID:27011755

Critical bending moment of implant-abutment screw joint interfaces: effect of torque levels and implant diameter.

PubMed

Tan, Ban Fui; Tan, Keson B; Nicholls, Jack I

2004-01-01

Critical bending moment (CBM), the moment at which the external nonaxial load applied overcomes screw joint preload and causes loss of contact between the mating surfaces of the implant screw joint components, was measured with 2 types of implants and 2 types of abutments. Using 4 test groups of 5 implant-abutment pairs, CBM at the implant-abutment screw joint was measured at 25%, 50%, 75%, and 100% of the manufacturer's recommended torque levels. Regular Platform (RP) Nobel Biocare implants (3.75 mm diameter), Wide Platform (WP) Nobel Biocare implants (5.0 mm diameter), CeraOne abutments, and Multiunit abutments were used. Microstrain was measured as loads were applied to the abutment at various distances from the implant-abutment interface. Strain instrumentation logged the strain data dynamically to determine the point of gap opening. All torque applications and strain measurements were repeated 5 times. For the CeraOne-RP group, the mean CBMs were 17.09 Ncm, 35.35 Ncm, 45.63 Ncm, and 62.64 Ncm at 25%, 50%, 75%, and 100% of the recommended torque level, respectively. For the CeraOne-WP group, mean CBMs were 28.29 Ncm, 62.97 Ncm, 92.20 Ncm, and 127.41 Ncm; for the Multiunit-RP group, 16.08 Ncm, 21.55 Ncm, 34.12 Ncm, and 39.46 Ncm; and for the Multiunit-WP group, 15.90 Ncm, 32.86 Ncm, 43.29 Ncm, and 61.55 Ncm at the 4 different torque levels. Two-way analysis of variance (ANOVA) (P < .001) revealed significant effects for the test groups (F = 2738.2) and torque levels (F = 2969.0). The methodology developed in this study allows confirmation of the gap opening of the screw joint for the test groups and determination of CBM at different torque levels. CBM was found to differ among abutment systems, implant diameters, and torque levels. The torque levels recommended by the manufacturer should followed to ensure screw joint integrity.

Efficacy and safety of concurrent collagenase clostridium histolyticum injections for multiple Dupuytren contractures.

PubMed

Coleman, Stephen; Gilpin, David; Kaplan, F Thomas D; Houston, Anthony; Kaufman, Gregory J; Cohen, Brian M; Jones, Nigel; Tursi, James P

2014-01-01

To assess the safety and efficacy of 2 concurrent injections of collagenase clostridium histolyticum (CCH) in the same hand to treat multiple Dupuytren flexion contractures. In a multicenter, open-label phase IIIb study, 60 patients received two 0.58-mg CCH doses injected into cords affecting 2 joints in the same hand during 1 visit, followed by finger extension approximately 24 hours later. Efficacy at postinjection day 30 (change in flexion contracture and active range of motion, patient satisfaction, physician-rated improvement, and rates of clinical success [flexion contracture 5° or less]) and adverse events were summarized. The concurrent injections were most commonly administered in cords affecting metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints on the same finger (47%) or 2 MCP joints on different fingers of the same hand (37%). Mean total (sum of the 2 treated joints) flexion contracture decreased 76%, from 87° to 24° (MCP joints: 86%; PIP joints: 66%). Mean total range of motion increased from 100° to 161°. Clinical success was 76% for MCP joints and 33% for PIP joints. Most patients were very satisfied (60%) or quite satisfied (28%) with treatment. Most investigators rated treated joints as very much improved (55%) or much improved (37%). The most common treatment-related adverse events (> 75% of patients) were contusion, pain in extremity, and edema peripheral (local edema). Most adverse events were mild to moderate in severity. Serious complications included 1 pulley rupture related to study medication and 1 flexor tendon rupture (following conclusion of the study). There were no systemic complications. Results suggest that 2 affected joints can be effectively and safely treated with concurrent CCH injections. There was an increased incidence of some adverse events with concurrent treatment (pruritus, lymphadenopathy, blood blister, and skin laceration) compared with treatment of a single joint. High degrees of patient satisfaction and physician-rated improvement were reported. Therapeutic IV. Copyright © 2014 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Reporting the Fatigue Life of 316L Stainless Steel Locking Compression Plate Implants: The Role of the Femoral and Tibial Biomechanics During the Gait.

PubMed

Rice, Devyn; Shaat, Mohamed

2017-10-01

In this study, the fatigue characteristics of femoral and tibial locking compression plate (LCP) implants are determined accounting for the knee biomechanics during the gait. A biomechanical model for the kinematics and kinetics of the knee joint during the complete gait cycle is proposed. The rotations of the femur, tibia, and patella about the knee joint during the gait are determined. Moreover, the patellar-tendon force (PT), quadriceps-tendon force (QT), the tibiofemoral joint force (TFJ), and the patellofemoral joint force (PFJ) through the standard gait cycle are obtained as functions of the body weight (BW). On the basis of the derived biomechanics of the knee joint, the fatigue factors of safety along with the fatigue life of 316L stainless steel femoral and tibial LCP implants are reported as functions of the BW and bone fracture location, for the first time. The reported results reveal that 316L stainless steel LCP implants for femoral surgeries are preferred for conditions in which the bone fracture is close to the knee joint and the BW is less than 80 kg. For tibial surgeries, 316L stainless steel LCP implants can be used for conditions in which the bone fracture is close to the knee joint and the BW is less than 100 kg. This study presents a critical guide for the determination of the fatigue characteristics of LCP implants. The obtained results reveal that the fatigue analyses should be performed on the basis of the body biomechanics to guarantee accurate designs of LCP implants for femoral and tibial orthopedic surgeries.

A Systematic Review of Different Implants and Approaches for Proximal Interphalangeal Joint Arthroplasty

PubMed Central

Yamamoto, Michiro; Malay, Sunitha; Fujihara, Yuki; Zhong, Lin; Chung, Kevin C.

2016-01-01

Background Outcomes after implant arthroplasty for primary degenerative and posttraumatic osteoarthritis (OA) of proximal interphalangeal (PIP) joint were different according to the implant design and surgical approach. The purpose of this systematic review was to evaluate outcomes of various types of implant arthroplasty for PIP joint OA with emphasis on different surgical approaches. Methods The authors searched all available literature in the PubMed and EMBASE databases for articles reporting on outcomes of implant arthroplasty for PIP joint OA. Data collection included active arc of motion (AOM), extension lag, and complications. We combined the data of various types of surface replacement arthroplasty into one group to compare with silicone arthroplasty. Results A total of 849 articles were screened, yielding 40 studies for final review. The mean postoperative AOM and the mean gain in AOM of silicone implant with volar approach were 58° and 17° respectively which was greater than surface replacement implant with dorsal approach as 51° and 8°, respectively. The mean postoperative extension lag of silicone implant with volar approach and surface replacement with dorsal approach was 5° and 14° respectively. The revision rate of silicone implant with volar approach and surface replacement with dorsal approach was 6% and 18% at the mean follow-up period of 41.2 and 51 months, respectively. Conclusions Silicone implant with volar approach showed the best AOM with less extension lag and fewer complications after surgery among all the implant designs and surgical approaches. PMID:28445369

Flexible Piezoelectric Energy Harvesting from Mouse Click Motions

PubMed Central

Cha, Youngsu; Hong, Jin; Lee, Jaemin; Park, Jung-Min; Kim, Keehoon

2016-01-01

In this paper, we study energy harvesting from the mouse click motions of a robot finger and a human index finger using a piezoelectric material. The feasibility of energy harvesting from mouse click motions is experimentally and theoretically assessed. The fingers wear a glove with a pocket for including the piezoelectric material. We model the energy harvesting system through the inverse kinematic framework of parallel joints in a finger and the electromechanical coupling equations of the piezoelectric material. The model is validated through energy harvesting experiments in the robot and human fingers with the systematically varying load resistance. We find that energy harvesting is maximized at the matched load resistance to the impedance of the piezoelectric material, and the harvested energy level is tens of nJ. PMID:27399705

Extrinsic and intrinsic index finger muscle attachments in an OpenSim upper-extremity model.

PubMed

Lee, Jong Hwa; Asakawa, Deanna S; Dennerlein, Jack T; Jindrich, Devin L

2015-04-01

Musculoskeletal models allow estimation of muscle function during complex tasks. We used objective methods to determine possible attachment locations for index finger muscles in an OpenSim upper-extremity model. Data-driven optimization algorithms, Simulated Annealing and Hook-Jeeves, estimated tendon locations crossing the metacarpophalangeal (MCP), proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints by minimizing the difference between model-estimated and experimentally-measured moment arms. Sensitivity analysis revealed that multiple sets of muscle attachments with similar optimized moment arms are possible, requiring additional assumptions or data to select a single set of values. The most smooth muscle paths were assumed to be biologically reasonable. Estimated tendon attachments resulted in variance accounted for (VAF) between calculated moment arms and measured values of 78% for flex/extension and 81% for ab/adduction at the MCP joint. VAF averaged 67% at the PIP joint and 54% at the DIP joint. VAF values at PIP and DIP joints partially reflected the constant moment arms reported for muscles about these joints. However, all moment arm values found through optimization were non-linear and non-constant. Relationships between moment arms and joint angles were best described with quadratic equations for tendons at the PIP and DIP joints.

Can physical joint simulators be used to anticipate clinical wear problems of new joint replacement implants prior to market release?

PubMed

Medley, John B

2016-05-01

One of the most important mandates of physical joint simulators is to provide test results that allow the implant manufacturer to anticipate and perhaps avoid clinical wear problems with their new products. This is best done before market release. This study gives four steps to follow in conducting such wear simulator testing. Two major examples involving hip wear simulators are discussed in which attempts had been made to predict clinical wear performance prior to market release. The second one, involving the DePuy ASR implant systems, is chosen for more extensive treatment by making it an illustrative example to explore whether wear simulator testing can anticipate clinical wear problems. It is concluded that hip wear simulator testing did provide data in the academic literature that indicated some risk of clinical wear problems prior to market release of the ASR implant systems. This supports the idea that physical joint simulators have an important role in the pre-market testing of new joint replacement implants. © IMechE 2016.

Deducing the reachable space from fingertip positions.

PubMed

Hai-Trieu Pham; Pathirana, Pubudu N

2015-01-01

The reachable space of the hand has received significant interests in the past from relevant medical researchers and health professionals. The reachable space was often computed from the joint angles acquired from a motion capture system such as gloves or markers attached to each bone of the finger. However, the contact between the hand and device can cause difficulties particularly for hand with injuries, burns or experiencing certain dermatological conditions. This paper introduces an approach to find the reachable space of the hand in a non-contact measurement form utilizing the Leap Motion Controller. The approach is based on the analysis of each position in the motion path of the fingertip acquired by the Leap Motion Controller. For each position of the fingertip, the inverse kinematic problem was solved under the physiological multiple constraints of the human hand to find a set of all possible configurations of three finger joints. Subsequently, all the sets are unified to form a set of all possible configurations specific for that motion. Finally, a reachable space is computed from the configuration corresponding to the complete extension and the complete flexion of the finger joint angles in this set.

Robust Hand Motion Tracking through Data Fusion of 5DT Data Glove and Nimble VR Kinect Camera Measurements

PubMed Central

Arkenbout, Ewout A.; de Winter, Joost C. F.; Breedveld, Paul

2015-01-01

Vision based interfaces for human computer interaction have gained increasing attention over the past decade. This study presents a data fusion approach of the Nimble VR vision based system, using the Kinect camera, with the contact based 5DT Data Glove. Data fusion was achieved through a Kalman filter. The Nimble VR and filter output were compared using measurements performed on (1) a wooden hand model placed in various static postures and orientations; and (2) three differently sized human hands during active finger flexions. Precision and accuracy of joint angle estimates as a function of hand posture and orientation were determined. Moreover, in light of possible self-occlusions of the fingers in the Kinect camera images, data completeness was assessed. Results showed that the integration of the Data Glove through the Kalman filter provided for the proximal interphalangeal (PIP) joints of the fingers a substantial improvement of 79% in precision, from 2.2 deg to 0.9 deg. Moreover, a moderate improvement of 31% in accuracy (being the mean angular deviation from the true joint angle) was established, from 24 deg to 17 deg. The metacarpophalangeal (MCP) joint was relatively unaffected by the Kalman filter. Moreover, the Data Glove increased data completeness, thus providing a substantial advantage over the sole use of the Nimble VR system. PMID:26694395

Robust Hand Motion Tracking through Data Fusion of 5DT Data Glove and Nimble VR Kinect Camera Measurements.

PubMed

Arkenbout, Ewout A; de Winter, Joost C F; Breedveld, Paul

2015-12-15

Vision based interfaces for human computer interaction have gained increasing attention over the past decade. This study presents a data fusion approach of the Nimble VR vision based system, using the Kinect camera, with the contact based 5DT Data Glove. Data fusion was achieved through a Kalman filter. The Nimble VR and filter output were compared using measurements performed on (1) a wooden hand model placed in various static postures and orientations; and (2) three differently sized human hands during active finger flexions. Precision and accuracy of joint angle estimates as a function of hand posture and orientation were determined. Moreover, in light of possible self-occlusions of the fingers in the Kinect camera images, data completeness was assessed. Results showed that the integration of the Data Glove through the Kalman filter provided for the proximal interphalangeal (PIP) joints of the fingers a substantial improvement of 79% in precision, from 2.2 deg to 0.9 deg. Moreover, a moderate improvement of 31% in accuracy (being the mean angular deviation from the true joint angle) was established, from 24 deg to 17 deg. The metacarpophalangeal (MCP) joint was relatively unaffected by the Kalman filter. Moreover, the Data Glove increased data completeness, thus providing a substantial advantage over the sole use of the Nimble VR system.

Prevention and Treatment of Arrhythmia

MedlinePlus

... your pulse – especially if you have an artificial pacemaker. Put the second and third fingers of one ... Ablation Devices for Arrhythmia - Implantable Cardioverter Defibrillator (ICD) - Pacemaker Treating Arrhythmias in Children • Arrhythmia Tools & Resources Watch, ...

Frequency of inflammatory-like MR imaging findings in asymptomatic fingers of healthy volunteers.

PubMed

Agten, Christoph A; Rosskopf, Andrea B; Jonczy, Maciej; Brunner, Florian; Pfirrmann, Christian W A; Buck, Florian M

2018-02-01

To describe the frequency of inflammatory-like findings on MR imaging in asymptomatic volunteers and compare them with patients with known rheumatoid arthritis and psoriatic arthritis. MR images of fingers in 42 asymptomatic volunteers and 33 patients with rheumatoid/psoriatic arthritis were analyzed. The Outcome Measures in Rheumatology Clinical Trials (OMERACT) Rheumatoid/Psoriatic Arthritis MRI Scoring System (RAMRIS/PsAMRIS) and tenosynovitis scoring system were used to assess: bone marrow edema (BME), erosions, tendon sheath fluid/tenosynovitis, joint effusion, and soft-tissue edema. Findings and scores were compared between volunteers and patients. Inter-reader agreement was calculated (intraclass correlation coefficients, ICC). In volunteers, tendon sheath fluid was very common in at least one location (42/42 volunteers for reader 1, 34/42 volunteers for reader 2). BME, erosions, joint effusion, and soft-tissue edema were absent (except one BME in the 3rd proximal phalanx for reader 1). Tendon sheath fluid scores in volunteers and tenosynovitis scores in patients were high (reader 1, 7.17 and 5.39; reader 2, 2.31 and 5.45). Overall, inter-reader agreement was substantial (ICC = 0.696-0.844), except for tendon sheath fluid (ICC = 0.258). Fluid in the finger flexor tendon sheaths may be a normal finding and without gadolinium administration should not be interpreted as tenosynovitis. Bone marrow edema, erosions, joint effusion, and soft-tissue edema in the fingers most likely reflect pathology if present.

Principal components of hand kinematics and neurophysiological signals in motor cortex during reach to grasp movements

PubMed Central

Aggarwal, Vikram; Thakor, Nitish V.; Schieber, Marc H.

2014-01-01

A few kinematic synergies identified by principal component analysis (PCA) account for most of the variance in the coordinated joint rotations of the fingers and wrist used for a wide variety of hand movements. To examine the possibility that motor cortex might control the hand through such synergies, we collected simultaneous kinematic and neurophysiological data from monkeys performing a reach-to-grasp task. We used PCA, jPCA and isomap to extract kinematic synergies from 18 joint angles in the fingers and wrist and analyzed the relationships of both single-unit and multiunit spike recordings, as well as local field potentials (LFPs), to these synergies. For most spike recordings, the maximal absolute cross-correlations of firing rates were somewhat stronger with an individual joint angle than with any principal component (PC), any jPC or any isomap dimension. In decoding analyses, where spikes and LFP power in the 100- to 170-Hz band each provided better decoding than other LFP-based signals, the first PC was decoded as well as the best decoded joint angle. But the remaining PCs and jPCs were predicted with lower accuracy than individual joint angles. Although PCs, jPCs or isomap dimensions might provide a more parsimonious description of kinematics, our findings indicate that the kinematic synergies identified with these techniques are not represented in motor cortex more strongly than the original joint angles. We suggest that the motor cortex might act to sculpt the synergies generated by subcortical centers, superimposing an ability to individuate finger movements and adapt the hand to grasp a wide variety of objects. PMID:24990564

Distribution of finger nodes and their association with underlying radiographic features of osteoarthritis.

PubMed

Rees, Frances; Doherty, Sally; Hui, Michelle; Maciewicz, Rose; Muir, Kenneth; Zhang, Weiya; Doherty, Michael

2012-04-01

To determine the distribution of clinically palpable hand interphalangeal (IP) nodes at each finger and thumb joint in a population with nodes, the influence of left or right hand dominance and sex on the development of nodes, and the association between nodes and underlying radiographic features of osteoarthritis (OA). We performed a cross-sectional analysis of participants in the Genetics of Osteoarthritis and Lifestyle (GOAL) study who had ≥1 Heberden's nodes or Bouchard's nodes on clinical examination. Frequencies (%) of nodes were described for each IP joint in the hand. Associations between nodes and underlying radiographic OA were shown with odds ratios (ORs) and 95% confidence intervals. A logistic regression model was used to adjust for the following confounding factors: age, sex, body mass index, left or right hand dominance, hand trauma, occupation with heavy manual activity, and participation in sports. Of the 3,170 GOAL participants, 1,939 had ≥1 nodes (mean age 68 years, 54% women). The distal IP joints of the index finger were the most frequently affected, followed by the thumb IP joint. Nodes were more common in dominant hands and women. There was a significant association between nodes and underlying radiographic OA (OR range 2.26-21.23). This association was stronger for joint space narrowing than for osteophytes. A dose-response relationship was found between clinical severity of Heberden's nodes and underlying radiographic change. Our study supports the positive association between nodes and radiographic OA, especially narrowing, and the influence of sex and left or right hand dominance on development of nodes. In this age group, presence of nodes may be taken as an indication of underlying small joint OA. Copyright © 2012 by the American College of Rheumatology.

Finger muscle attachments for an OpenSim upper-extremity model.

PubMed

Lee, Jong Hwa; Asakawa, Deanna S; Dennerlein, Jack T; Jindrich, Devin L

2015-01-01

We determined muscle attachment points for the index, middle, ring and little fingers in an OpenSim upper-extremity model. Attachment points were selected to match both experimentally measured locations and mechanical function (moment arms). Although experimental measurements of finger muscle attachments have been made, models differ from specimens in many respects such as bone segment ratio, joint kinematics and coordinate system. Likewise, moment arms are not available for all intrinsic finger muscles. Therefore, it was necessary to scale and translate muscle attachments from one experimental or model environment to another while preserving mechanical function. We used a two-step process. First, we estimated muscle function by calculating moment arms for all intrinsic and extrinsic muscles using the partial velocity method. Second, optimization using Simulated Annealing and Hooke-Jeeves algorithms found muscle-tendon paths that minimized root mean square (RMS) differences between experimental and modeled moment arms. The partial velocity method resulted in variance accounted for (VAF) between measured and calculated moment arms of 75.5% on average (range from 48.5% to 99.5%) for intrinsic and extrinsic index finger muscles where measured data were available. RMS error between experimental and optimized values was within one standard deviation (S.D) of measured moment arm (mean RMS error = 1.5 mm < measured S.D = 2.5 mm). Validation of both steps of the technique allowed for estimation of muscle attachment points for muscles whose moment arms have not been measured. Differences between modeled and experimentally measured muscle attachments, averaged over all finger joints, were less than 4.9 mm (within 7.1% of the average length of the muscle-tendon paths). The resulting non-proprietary musculoskeletal model of the human fingers could be useful for many applications, including better understanding of complex multi-touch and gestural movements.

Finger Muscle Attachments for an OpenSim Upper-Extremity Model

PubMed Central

Lee, Jong Hwa; Asakawa, Deanna S.; Dennerlein, Jack T.; Jindrich, Devin L.

2015-01-01

We determined muscle attachment points for the index, middle, ring and little fingers in an OpenSim upper-extremity model. Attachment points were selected to match both experimentally measured locations and mechanical function (moment arms). Although experimental measurements of finger muscle attachments have been made, models differ from specimens in many respects such as bone segment ratio, joint kinematics and coordinate system. Likewise, moment arms are not available for all intrinsic finger muscles. Therefore, it was necessary to scale and translate muscle attachments from one experimental or model environment to another while preserving mechanical function. We used a two-step process. First, we estimated muscle function by calculating moment arms for all intrinsic and extrinsic muscles using the partial velocity method. Second, optimization using Simulated Annealing and Hooke-Jeeves algorithms found muscle-tendon paths that minimized root mean square (RMS) differences between experimental and modeled moment arms. The partial velocity method resulted in variance accounted for (VAF) between measured and calculated moment arms of 75.5% on average (range from 48.5% to 99.5%) for intrinsic and extrinsic index finger muscles where measured data were available. RMS error between experimental and optimized values was within one standard deviation (S.D) of measured moment arm (mean RMS error = 1.5 mm < measured S.D = 2.5 mm). Validation of both steps of the technique allowed for estimation of muscle attachment points for muscles whose moment arms have not been measured. Differences between modeled and experimentally measured muscle attachments, averaged over all finger joints, were less than 4.9 mm (within 7.1% of the average length of the muscle-tendon paths). The resulting non-proprietary musculoskeletal model of the human fingers could be useful for many applications, including better understanding of complex multi-touch and gestural movements. PMID:25853869

Comparative study of the detection of joint injury in early-stage rheumatoid arthritis by magnetic resonance imaging of the wrist and finger joints and physical examination.

PubMed

Tamai, Mami; Kawakami, Atsushi; Iwamoto, Naoki; Kawashiri, Shin-Ya; Fujikawa, Keita; Aramaki, Toshiyuki; Kita, Junko; Okada, Akitomo; Koga, Tomohiro; Arima, Kazuhiko; Kamachi, Makoto; Yamasaki, Satoshi; Nakamura, Hideki; Ida, Hiroaki; Origuchi, Tomoki; Takao, Shoichiro; Aoyagi, Kiyoshi; Uetani, Masataka; Eguchi, Katsumi

2011-03-01

To verify whether magnetic resonance imaging (MRI)-proven joint injury is sensitive as compared with joint injury determined by physical examination. MRI of the wrist and finger joints of both hands was examined in 51 early-stage rheumatoid arthritis (RA) patients by both plain and gadolinium diethylenetriaminepentaacetic acid-enhanced MRI. Synovitis, bone edema, and bone erosion (the latter two included as bone lesions at the wrist joints); metacarpophalangeal joints; and proximal interphalangeal joints were considered as MRI-proven joint injury. Japan College of Rheumatology-certified rheumatologists had given a physical examination just before the MRI study. The presence of tender and/or swollen joints in the same fields as MRI was considered as joint injury on physical examination. The association of MRI-proven joint injury with physical examination-proven joint injury was examined. A total of 1,110 sites were available to be examined. MRI-proven joint injury was found in 521 sites, whereas the other 589 sites were normal. Physical examination-proven joint injury was found in 305 sites, which was significantly low as compared with MRI-proven joint injury (P = 1.1 × 10(-12) versus MRI). Joint injury on physical examination was not found in 81.5% of the sites where MRI findings were normal. Furthermore, an association of the severity of MRI-proven joint injury with that of joint injury on physical examination was clearly demonstrated (P = 1.6 × 10(-15), r(s) = 0.469). Our present data suggest that MRI is not only sensitive but accurately reflects the joint injury in patients with early-stage RA. Copyright © 2011 by the American College of Rheumatology.

Power assist EVA glove development

NASA Technical Reports Server (NTRS)

Main, John A.; Peterson, Steven W.; Strauss, Alvin M.

1992-01-01

Structural modeling of the EVA glove indicates that flexibility in the metacarpophalangeal (MCP) joint can be improved by selectively lowering the elasticity of the glove fabric. Two strategies are used to accomplish this. One method uses coil springs on the back of the glove to carry the tension in the glove skin due to pressurization. These springs carry the loads normally borne by the glove fabric, but are more easily deformed. An active system was also designed for the same purpose and uses gas filled bladders attached to the back of the EVA glove that change the dimensions of the back of the glove and allow the glove to bend at the MCP joint, thus providing greater flexibility at this joint. A threshold control scheme was devised to control the action of the joint actuators. Input to the controller was provided by thin resistive pressure sensors placed between the hand and the pressurized glove. The pressure sensors consist of a layer of polyester film that has a thin layer of ink screened on the surface. The resistivity of the ink is pressure dependent, so an extremely thin pressure sensor can be fabricated by covering the ink patch with another layer of polyester film and measuring the changing resistance of the ink with a bridge circuit. In order to sense the force between the hand and the glove at the MCP joint, a sensor was placed on the palmar face of the middle finger. The resultant signal was used by the controller to decide whether to fill or exhaust the bladder actuators on the back of the glove. The information from the sensor can also be used to evaluate the effectiveness of a given control scheme or glove design since the magnitude of the measured pressures gives some idea of the torque required to bend a glove finger at the MCP joint. Tests of this actuator, sensor, and control system were conducted in an 57.2 kPa glove box by performing a series of 90 degree finger bends with a glove without an MCP joint assembly, a glove with the coil spring assembly, and with the four fingered actuated glove. The tests of these three glove designs confirm the validity of the model.

Using Arrays of Microelectrodes Implanted in Residual Peripheral Nerves to Provide Dexterous Control of, and Modulated Sensory Feedback from, a Hand Prosthesis

DTIC Science & Technology

2017-10-01

potentials or multi-action potential activity from residual peripheral nerve while patient intends movements of amputated hand/arm Subtask 3.1: Mapping of...neural activity (Months 4 – 36) • Patients will be asked to intend a number of individual finger and multiple finger flexion, extension, adduction...intended movements. We will map the different intended movements onto the neural activity recorded on the electrodes of the micro-electrode array

Using Arrays of Microelectrodes Implanted in Residual Peripheral Nerves to Provide Dexterous Control of, and Modulated Sensory Feedback from, a Hand Prosthesis

DTIC Science & Technology

2016-10-01

isolated action potentials or multi-action potential activity from residual peripheral nerve while patient intends movements of amputated hand/arm...Subtask 3.1: Mapping of neural activity (Months 4 – 36) • Patients will be asked to intend a number of individual finger and multiple finger flexion...during these intended movements. We will map the different intended movements onto the neural activity recorded on the electrodes of the micro-electrode

An evaluation of the spring finger solder joints on SA1358-10 and SA2052-4 connector assemblies (MC3617,W87).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kilgo, Alice C.; Vianco, Paul Thomas; Hlava, Paul Frank

2006-08-01

The SA1358-10 and SA2052-4 circular JT Type plug connectors are used on a number of nuclear weapons and Joint Test Assembly (JTA) systems. Prototype units were evaluated for the following specific defects associated with the 95Sn-5Sb (Sn-Sb, wt.%) solder joint used to attach the beryllium-copper (BeCu) spring fingers to the aluminum (Al) connector shell: (1) extended cracking within the fillet; (2) remelting of the solder joint during the follow-on, soldering step that attached the EMR adapter ring to the connector shell (and/or soldering the EMR shell to the adapter ring) that used the lower melting temperature 63Sn-37Pb (Sn-Pb) alloy; andmore » (3) spalling of the Cd (Cr) layer overplating layer from the fillet surface. Several pedigrees of connectors were evaluated, which represented older fielded units as well as those assemblies that were recently constructed at Kansas City Plant. The solder joints were evaluated that were in place on connectors made with the current soldering process as well as an alternative induction soldering process for attaching the EMR adapter ring to the shell. Very similar observations were made, which crossed the different pedigrees of parts and processes. The extent of cracking in the top side fillets varied between the different connector samples and likely the EMR adapter ring to the shell. Very similar observations were made, which crossed the different pedigrees of parts and processes. The extent of cracking in the top side fillets varied between the different connector samples and likely reflected the different extents to which the connector was mated to its counterpart assembly. In all cases, the spring finger solder joints on the SA1358-10 connectors were remelted as a result of the subsequent EMR adapter ring attachment process. Spalling of the Cd (Cr) overplating layer was also observed for these connectors, which was a consequence of the remelting activity. On the other hand, the SA2052-4 connector did not exhibit evidence of remelting of the spring finger solder joint. The Cd (Cr) layer did not show signs of spalling. These results suggested that, due to the size of the SA1358-10 connector, any of the former or current soldering processes used to attach the EMR adapter ring and/or EMR shell to the connector shell, requires a level of heat energy that will always result in the remelting of the spring finger solder joint attached with either the Sn-Ag or the Sn-Sb alloy. Lastly, it was construed that the induction soldering process, which is used to attach the EMR adapter ring onto the shell, was more likely to have caused the remelting event rather than the more localized heat source of the hand soldering iron used to attach the EMR shell to the adapter ring.« less

Geometric features of workspace and joint-space paths of 3D reaching movements.

PubMed

Klein Breteler, M D; Meulenbroek, R G; Gielen, S C

1998-11-01

The present study focuses on geometric features of workspace and joint-space paths of three-dimensional reaching movements. Twelve subjects repeatedly performed a three-segment, triangular-shaped movement pattern in an approximately 60 degrees tilted horizontal plane. Task variables elicited movement patterns that varied in position, rotational direction and speed. Trunk, arm, hand and finger-tip movements were recorded by means of a 3D motion-tracking system. Angular excursions of the shoulder and elbow joints were extracted from position data. Analyses of the shape of 3D workspace and joint-space paths focused on the extent to which the submovements were produced in a plane, and on the curvature of the central parts of the submovements. A systematic tendency to produce movements in a plane was found in addition to an increase of finger-tip path curvature with increasing speed. The findings are discussed in relation to the role of optimization principles in trajectory-formation models.

The immediate effects of therapeutic keyboard music playing for finger training in adults undergoing hand rehabilitation.

PubMed

Zhang, Xiaoying; Liu, Songhuai; Yang, Degang; Du, Liangjie; Wang, Ziyuan

2016-08-01

[Purpose] The purpose of this study was to examine the immediate effects of therapeutic keyboard music playing on the finger function of subjects' hands through measurements of the joint position error test, surface electromyography, probe reaction time, and writing time. [Subjects and Methods] Ten subjects were divided randomly into experimental and control groups. The experimental group used therapeutic keyboard music playing and the control group used grip training. All subjects were assessed and evaluated by the joint position error test, surface electromyography, probe reaction time, and writing time. [Results] After accomplishing therapeutic keyboard music playing and grip training, surface electromyography of the two groups showed no significant change, but joint position error test, probe reaction time, and writing time obviously improved. [Conclusion] These results suggest that therapeutic keyboard music playing is an effective and novel treatment for improving joint position error test scores, probe reaction time, and writing time, and it should be promoted widely in clinics.

Intra-articular implantation of gentamicin impregnated collagen sponge causes joint inflammation and impaired renal function in dogs.

PubMed

Hayes, Galina; Gibson, Tom; Moens, Noel M M; Nykamp, Stephanie; Wood, Darren; Foster, Robert; Lerer, Asaf

2016-01-01

Gentamicin impregnated collagen sponge (GICS) can be used to treat intra-articular surgical site infections. High local concentrations of gentamicin can be reached for short periods; however the collagen vehicle may persist for much longer periods. We wished to determine the effect of sponge implantation on joint inflammation and renal function. Eighteen medium sized mixed breed research dogs of hound type were randomized to two groups; arthroscopic implantation of GICS at gentamicin dose = 6 mg/kg (n = 9) or sham operation (n = 9). Endpoints consisted of joint inflammation measured by synovial fluid cell counts and cytokine concentrations; lameness measured by force plate asymmetry indices; and renal function measured by glomerular filtration rate (GFR) study. The prevalence of lesions associated with aminoglycoside nephrotoxicity was assessed by renal biopsy and transmission electron microscopy. Gentamicin impregnated collagen sponge implantation caused joint inflammation (p <0.01), lameness (p = 0.04), and decreased GFR (p = 0.04). No difference was observed in the prevalence of renal lesions on biopsy between the treatment and control groups (p = 0.49). Gentamicin impregnated collagen sponge implantation causes joint inflammation and lameness as well as GFR reductions at the dose assessed. Gentamicin impregnated collagen sponge are not recommended for intra-articular implantation in dogs.

Effect of total shoulder replacements on airport security screening in the post-9/11 era.

PubMed

Dines, Joshua S; Elkousy, Hussein; Edwards, T Bradley; Gartsman, Gary M; Dines, David M

2007-01-01

There are few reports in the literature on the effect of orthopaedic implants on airport security devices and none on shoulder arthroplasty implants after September 11, 2001. Since 9/11, airport security screening devices have become more sensitive in response to the increasing threat of terrorism. Often, patients with joint implants activate the metal detectors and are subsequently subjected to more intensive screening. We assess the effects of shoulder joint implants on different airport security devices and what effect the results had on passenger travel. In this study, 154 patients who had previously undergone shoulder replacement responded to a questionnaire regarding their travel experiences after 9/11. Of these, 85 had flown during the time period studied (47 men and 38 women; mean age, 67.8 years); 79 had traveled domestically (mean, 7 flights), and 22 had taken international flights (mean, 6.1 flights). The questionnaire addressed each patient's height/weight, the number of flight segments flown (domestic and international), the number of times that a patient activated the doorway alarm/wand alarm, and the effect of a card stating that the patient had joint replacement (when applicable). On average, patients with shoulder replacement traveling domestically activated the security gate 52% of the time. The average for international travel was 42%. Of the patients who flew both domestically and internationally, there was a high correlation of activation (R = 0.54). Twenty-six patients had multiple joint implants (mean, 2.8). Multiple joint implants caused increased alarm activation (P < .001). All patients reported that their travel was delayed during the instances of security activation. There was no statistically significant effect of body mass index, height, weight, age, or sex on security device activation. Of the patients, 71% were told by their doctor that the shoulder replacement may activate security devices. Of these, 46 were given a card by their doctor indicating the presence of a total joint implant. In only 30% of the security encounters of these patients did the card expedite the screening process. This is the largest study on the effects of joint implants, and shoulder implants in particular, on airport security devices and the only one that has analyzed the data of post-9/11 travel. Patients traveling after total shoulder replacement are often delayed and subjected to more rigorous screening when traveling, especially in the post-9/11 environment. Doctors often warn their patients of potential problems and may try to avert this by giving them cards documenting the presence of a joint implant. The acceptance of these cards is sporadic. This study raises the importance of notifying patients of potential security delays, especially those with multiple joint implants, as they may directly affect travel plans. In addition, these patients may benefit from the establishment of an international joint registry.

Can a Soft Robotic Probe Use Stiffness Control Like a Human Finger to Improve Efficacy of Haptic Perception?

PubMed

Sornkarn, Nantachai; Nanayakkara, Thrishantha

2017-01-01

When humans are asked to palpate a soft tissue to locate a hard nodule, they regulate the stiffness, speed, and force of the finger during examination. If we understand the relationship between these behavioral variables and haptic information gain (transfer entropy) during manual probing, we can improve the efficacy of soft robotic probes for soft tissue palpation, such as in tumor localization in minimally invasive surgery. Here, we recorded the muscle co-contraction activity of the finger using EMG sensors to address the question as to whether joint stiffness control during manual palpation plays an important role in the haptic information gain. To address this question, we used a soft robotic probe with a controllable stiffness joint and a force sensor mounted at the base to represent the function of the tendon in a biological finger. Then, we trained a Markov chain using muscle co-contraction patterns of human subjects, and used it to control the stiffness of the soft robotic probe in the same soft tissue palpation task. The soft robotic experiments showed that haptic information gain about the depth of the hard nodule can be maximized by varying the internal stiffness of the soft probe.

A Systematic Review of Different Implants and Approaches for Proximal Interphalangeal Joint Arthroplasty.

PubMed

Yamamoto, Michiro; Malay, Sunitha; Fujihara, Yuki; Zhong, Lin; Chung, Kevin C

2017-05-01

Outcomes after implant arthroplasty for primary degenerative and posttraumatic osteoarthritis of the proximal interphalangeal joint were different according to the implant design and surgical approach. The purpose of this systematic review was to evaluate outcomes of various types of implant arthroplasty for proximal interphalangeal joint osteoarthritis, with an emphasis on different surgical approaches. The authors searched all available literature in the PubMed and EMBASE databases for articles reporting on outcomes of implant arthroplasty for proximal interphalangeal joint osteoarthritis. Data collection included active arc of motion, extension lag, and complications. The authors combined the data of various types of surface replacement arthroplasty into one group for comparison with silicone arthroplasty. A total of 849 articles were screened, yielding 40 studies for final review. The mean postoperative arc of motion and the mean gain in arc of motion of silicone implant with the volar approach were 58 and 17 degrees, respectively, which was greater than surface replacement implant with the dorsal approach at 51 and 8 degrees, respectively. The mean postoperative extension lag of silicone implant with the volar approach and surface replacement with the dorsal approach was 5 and 14 degrees, respectively. The revision rate of silicone implant with the volar approach and surface replacement with the dorsal approach was 6 percent and 18 percent at a mean follow-up of 41.2 and 51 months, respectively. Silicone implant with the volar approach showed the best arc of motion, with less extension lag and fewer complications after surgery among all the implant designs and surgical approaches.

The added value of measuring thumb and finger strength when comparing strength measurements in hypoplastic thumb patients.

PubMed

Molenaar, H M Ties; Selles, Ruud W; de Kraker, Marjolein; Stam, Henk J; Hovius, Steven E R

2013-10-01

When interventions to the hand are aimed at improving function of specific fingers or the thumb, the RIHM (Rotterdam Intrinsic Hand Myometer) is a validated tool and offers more detailed information to assess strength of the involved joints besides grip and pinch measurements. In this study, strength was measured in 65 thumbs in 40 patients diagnosed with thumb hypoplasia. These 65 thumbs were classified according to Blauth. Longitudinal radial deficiencies were also classified. The strength measurements comprised of grip, tip, tripod and key pinch. Furthermore palmar abduction and opposition of the thumb as well as abduction of the index and little finger were measured with the RIHM. For all longitudinal radial deficiency patients, grip and pinch strength as well as palmar abduction and thumb opposition were significantly lower than reference values (P<0.001). However, strength in the index finger abduction and the little finger abduction was maintained or decreased to a lesser extent according to the degree of longitudinal radial deficiency. All strength values decreased with increasing Blauth-type. Blauth-type II hands (n=15) with flexor digitorum superficialis 4 opposition transfer including stabilization of the metacarpophalangeal joint showed a trend toward a higher opposition strength without reaching statistical significance (P=0.094),however compared to non-operated Blauth-type II hands (n=6) they showed a lower grip strength (P=0.019). The RIHM is comparable in accuracy to other strength dynamometers. Using the RIHM, we were able to illustrate strength patterns on finger-specific level, showing added value when evaluating outcome in patients with hand related problems. © 2013.

[Study of mechanical effects of the EVA glove on finger base with finite element modeling].

PubMed

Li, Zhuoyou; Ding, Li; Yue, Guodong

2013-08-01

The hand strength of astronauts, when they are outside the space capsule, is highly influenced by the residual pressure (the pressure difference between inside pressure and outside one of the suit) of extravehicular activity spacesuit glove and the pressure exerted by braided fabric. The hand strength decreases significantly on extravehicular activity, severely reducing the operation efficiency. To measure mechanical influence caused by spacesuit glove on muscle-tendon and joints, the present paper analyzes the movement anatomy and biomechanical characteristics of gripping, and then proposes a grip model. With phalangeal joint simplified as hinges, seven muscles as a finger grip energy unit, the Hill muscle model was used to compute the effects. We also used ANSYS in this study to establish a 3-D finite element model of an index finger which included both bones and muscles with glove, and then we verified the model. This model was applied to calculate the muscle stress in various situations of bare hands or hands wearing gloves in three different sizes. The results showed that in order to achieve normal grip strength with the influence caused by superfluous press, the finger's muscle stress should be increased to 5.4 times of that in normal situation, with most of the finger grip strength used to overcome the influence of superfluous pressure. When the gap between the finger surface and the glove is smaller, the mechanical influence which superfluous press made will decrease. The results would provide a theoretical basis for the design of the EVA Glove.

Surgeons' Perspectives on Premium Implants in Total Joint Arthroplasty.

PubMed

Wasterlain, Amy S; Bello, Ricardo J; Vigdorchik, Jonathan; Schwarzkopf, Ran; Long, William J

2017-09-01

Declining total joint arthroplasty reimbursement and rising implant prices have led many hospitals to restrict access to newer, more expensive total joint arthroplasty implants. The authors sought to understand arthroplasty surgeons' perspectives on implants regarding innovation, product launch, costs, and cost-containment strategies including surgeon gain-sharing and patient cost-sharing. Members of the International Congress for Joint Reconstruction were surveyed regarding attitudes about implant technology and costs. Descriptive and univariate analyses were performed. A total of 126 surgeons responded from all 5 regions of the United States. Although 76.9% believed new products advance technology in orthopedics, most (66.7%) supported informing patients that new implants lack long-term clinical data and restricting new implants to a small number of investigators prior to widespread market launch. The survey revealed that 66.7% would forgo gain-sharing incentives in exchange for more freedom to choose implants. Further, 76.9% believed that patients should be allowed to pay incremental costs for "premium" implants. Surgeons who believed that premium products advance orthopedic technology were more willing to forgo gain-sharing (P=.040). Surgeons with higher surgical volume (P=.007), those who believed implant companies should be allowed to charge more for new technology (P<.001), and those who supported discussing costs with patients (P=.004) were more supportive of patient cost-sharing. Most arthroplasty surgeons believe technological innovation advances the field but support discussing the "unproven" nature of new implants with patients. Many surgeons support alternative payment models permitting surgeons and patients to retain implant selection autonomy. Most respondents prioritized patient beneficence and surgeon autonomy above personal financial gain. [Orthopedics. 2017; 40(5):e825-e830.]. Copyright 2017, SLACK Incorporated.

Digital ranges of motion: normal values in young adults.

PubMed

Mallon, W J; Brown, H R; Nunley, J A

1991-09-01

Analysis of the range of motion of fingers was done in young (eighteen to thirty-five year old) adult volunteers with no history of previous injury to their hands. The data show that there are slight differences between the individual digits. Notably, metacarpophalangeal flexion and total active motion increase linearly in proceeding from the index to the small finger. There were also minor differences in comparing sexes. Women have greater extension at the metacarpophalangeal joint in both active and passive motion and have a greater total active motion at all digits as a result. A significant tenodesis effect was found at the distal interphalangeal joint in normal subjects. No differences were found that could be attributable to handedness.

Towards real-time medical diagnostics using hyperspectral imaging technology

NASA Astrophysics Data System (ADS)

Bjorgan, Asgeir; Randeberg, Lise L.

2015-07-01

Hyperspectral imaging provides non-contact, high resolution spectral images which has a substantial diagnostic potential. This can be used for e.g. diagnosis and early detection of arthritis in finger joints. Processing speed is currently a limitation for clinical use of the technique. A real-time system for analysis and visualization using GPU processing and threaded CPU processing is presented. Images showing blood oxygenation, blood volume fraction and vessel enhanced images are among the data calculated in real-time. This study shows the potential of real-time processing in this context. A combination of the processing modules will be used in detection of arthritic finger joints from hyperspectral reflectance and transmittance data.

Local sensory control of a dexterous end effector

NASA Technical Reports Server (NTRS)

Pinto, Victor H.; Everett, Louis J.; Driels, Morris

1990-01-01

A numerical scheme was developed to solve the inverse kinematics for a user-defined manipulator. The scheme was based on a nonlinear least-squares technique which determines the joint variables by minimizing the difference between the target end effector pose and the actual end effector pose. The scheme was adapted to a dexterous hand in which the joints are either prismatic or revolute and the fingers are considered open kinematic chains. Feasible solutions were obtained using a three-fingered dexterous hand. An algorithm to estimate the position and orientation of a pre-grasped object was also developed. The algorithm was based on triangulation using an ideal sensor and a spherical object model. By choosing the object to be a sphere, only the position of the object frame was important. Based on these simplifications, a minimum of three sensors are needed to find the position of a sphere. A two dimensional example to determine the position of a circle coordinate frame using a two-fingered dexterous hand was presented.

Design and Validation of Implantable Passive Mechanisms for Orthopedic Surgery

DTIC Science & Technology

2017-10-01

have post-surgery? Please put the designated grading next to each picture. 2. When comparing to the force applied by the index finger, what percentage...system, when compared with using the direct suture. This concept is inspired by the use of such mechanisms in the design of “underactuated” robotic...AWARD NUMBER: W81XWH-16-1-0794 TITLE: Design and Validation of Implantable Passive Mechanisms for Orthopedic Surgery PRINCIPAL INVESTIGATOR

[The development of a finger joint phantom for the optical simulation of early inflammatory rheumatic changes].

PubMed

Prapavat, V; Runge, W; Mans, J; Krause, A; Beuthan, J; Müller, G

1997-11-01

In the field of rheumatology, conventional diagnostic methods permit the detection only of advanced stages of the disease, which is at odds with the current clinical demand for the early diagnosis of inflammatory rheumatic diseases. Prompted by current needs, we developed a finger joint phantom that enables the optical and geometrical simulation of an early stage of rheumatoid arthritis (RA). The results presented here form the experimental basis for an evaluation of new RA diagnostic systems based on near infrared light. The early stage of RA is characterised mainly by a vigorous proliferation of the synovial membrane and clouding of the synovial fluid. Using a double-integrating-sphere technique, the absorption and scattering coefficients (mua, mus') are experimentally determined for healthy and pathologically altered synovial fluid and capsule tissue. Using a variable mixture of Intralipid Indian ink and water as a scattering/absorption medium, the optical properties of skin, synovial fluid or capsule can be selected individually. Since the optical and geometrical properties of bone tissue remain constant in early-stage RA, a solid material is used for its simulation. Using the finger joint phantom described herein, the optical properties of joint regions can be adjusted specifically, enabling an evaluation of their effects on an optical signal--for example, during fluorography--and the investigation of these effects for diagnostically useful information. The experimental foundation for the development of a new optical system for the early diagnosis of RA has now been laid.

Optical clearing of human skin for the enhancement of optical imaging of proximal interphalangeal joints

NASA Astrophysics Data System (ADS)

Kolesnikova, Ekaterina A.; Kolesnikov, Aleksandr S.; Zabarylo, Urszula; Minet, Olaf; Genina, Elina A.; Bashkatov, Alexey N.; Tuchin, Valery V.

2014-01-01

We are proposing a new method for enhancement of optical imaging of proximal interphalangeal (PIP) joints in humans at skin using optical clearing technique. A set of illuminating laser diodes with the wavelengths 670, 820, and 904 nm were used as a light source. The laser diodes, monochromatic digital CCD camera and specific software allowed for detection of the finger joint image in a transillumination mode. The experiments were carried out in vivo with human fingers. Dehydrated glycerol and hand cream with urea (5%) were used as optical clearing agents (OCAs). The contrast of the obtained images was analyzed to determine the effect of the OCA. It was found that glycerol application to the human skin during 60 min caused the decrease of contrast in 1.4 folds for 670 nm and the increase of contrast in 1.5 and 1.7 folds for 820 nm and 904 nm, respectively. At the same time, the hand cream application to the human skin during 60 min caused the decrease of contrast in 1.1 folds for 670 nm and the increase of contrast in 1.3 and 1.1 folds for 820 nm and 904 nm, respectively. The results have shown that glycerol and the hand cream with 5% urea allow for obtaining of more distinct image of finger joint in the NIR. Obtained data can be used for development of optical diagnostic methods of rheumatoid arthritis.

Novel biological strategies for treatment of wear particle-induced periprosthetic osteolysis of orthopaedic implants for joint replacement

PubMed Central

Goodman, S. B.; Gibon, E.; Pajarinen, J.; Lin, T.-H.; Keeney, M.; Ren, P.-G.; Nich, C.; Yao, Z.; Egashira, K.; Yang, F.; Konttinen, Y. T.

2014-01-01

Wear particles and by-products from joint replacements and other orthopaedic implants may result in a local chronic inflammatory and foreign body reaction. This may lead to persistent synovitis resulting in joint pain and swelling, periprosthetic osteolysis, implant loosening and pathologic fracture. Strategies to modulate the adverse effects of wear debris may improve the function and longevity of joint replacements and other orthopaedic implants, potentially delaying or avoiding complex revision surgical procedures. Three novel biological strategies to mitigate the chronic inflammatory reaction to orthopaedic wear particles are reported. These include (i) interference with systemic macrophage trafficking to the local implant site, (ii) modulation of macrophages from an M1 (pro-inflammatory) to an M2 (anti-inflammatory, pro-tissue healing) phenotype in the periprosthetic tissues, and (iii) local inhibition of the transcription factor nuclear factor kappa B (NF-κB) by delivery of an NF-κB decoy oligodeoxynucleotide, thereby interfering with the production of pro-inflammatory mediators. These three approaches have been shown to be viable strategies for mitigating the undesirable effects of wear particles in preclinical studies. Targeted local delivery of specific biologics may potentially extend the lifetime of orthopaedic implants. PMID:24478281

Continuous and simultaneous estimation of finger kinematics using inputs from an EMG-to-muscle activation model.

PubMed

Ngeo, Jimson G; Tamei, Tomoya; Shibata, Tomohiro

2014-08-14

Surface electromyography (EMG) signals are often used in many robot and rehabilitation applications because these reflect motor intentions of users very well. However, very few studies have focused on the accurate and proportional control of the human hand using EMG signals. Many have focused on discrete gesture classification and some have encountered inherent problems such as electro-mechanical delays (EMD). Here, we present a new method for estimating simultaneous and multiple finger kinematics from multi-channel surface EMG signals. In this study, surface EMG signals from the forearm and finger kinematic data were extracted from ten able-bodied subjects while they were tasked to do individual and simultaneous multiple finger flexion and extension movements in free space. Instead of using traditional time-domain features of EMG, an EMG-to-Muscle Activation model that parameterizes EMD was used and shown to give better estimation performance. A fast feed forward artificial neural network (ANN) and a nonparametric Gaussian Process (GP) regressor were both used and evaluated to estimate complex finger kinematics, with the latter rarely used in the other related literature. The estimation accuracies, in terms of mean correlation coefficient, were 0.85 ± 0.07, 0.78 ± 0.06 and 0.73 ± 0.04 for the metacarpophalangeal (MCP), proximal interphalangeal (PIP) and the distal interphalangeal (DIP) finger joint DOFs, respectively. The mean root-mean-square error in each individual DOF ranged from 5 to 15%. We show that estimation improved using the proposed muscle activation inputs compared to other features, and that using GP regression gave better estimation results when using fewer training samples. The proposed method provides a viable means of capturing the general trend of finger movements and shows a good way of estimating finger joint kinematics using a muscle activation model that parameterizes EMD. The results from this study demonstrates a potential control strategy based on EMG that can be applied for simultaneous and continuous control of multiple DOF(s) devices such as robotic hand/finger prostheses or exoskeletons.

A finger exoskeleton for rehabilitation and brain image study.

PubMed

Tang, Zhenjin; Sugano, Shigeki; Iwata, Hiroyasu

2013-06-01

This paper introduces the design, fabrication and evaluation of the second generation prototype of a magnetic resonance compatible finger rehabilitation robot. It can not only be used as a finger rehabilitation training tool after a stroke, but also to study the brain's recovery process during the rehabilitation therapy (ReT). The mechanical design of the current generation has overcome the disadvantage in the previous version[13], which can't provide precise finger trajectories during flexion and extension motion varying with different finger joints' torques. In addition, in order to study the brain activation under different training strategies, three control modes have been developed, compared to only one control mode in the last prototype. The current prototype, like the last version, uses an ultrasonic motor as its actuator to enable the patient to do extension and flexion rehabilitation exercises in two degrees of freedom (DOF) for each finger. Finally, experiments have been carried out to evaluate the performances of this device.

Selective recruitment of single motor units in human flexor digitorum superficialis muscle during flexion of individual fingers.

PubMed

Butler, T J; Kilbreath, S L; Gorman, R B; Gandevia, S C

2005-08-15

Flexor digitorum superficialis (FDS) is an extrinsic multi-tendoned muscle which flexes the proximal interphalangeal joints of the four fingers. It comprises four digital components, each with a tendon that inserts onto its corresponding finger. To determine the degree to which these digital components can be selectively recruited by volition, we recorded the activity of a single motor unit in one component via an intramuscular electrode while the subject isometrically flexed each of the remaining fingers, one at a time. The finger on which the unit principally acted was defined as the 'test finger' and that which flexed isometrically was the 'active' finger. Activity in 79 units was recorded. Isometric finger flexion forces of 50% maximum voluntary contraction (MVC) activated less than 50% of single units in components of FDS acting on fingers that were not voluntarily flexed. With two exceptions, the median recruitment threshold for all active-test finger combinations involving the index, middle, ring and little finger test units was between 49 and 60% MVC (60% MVC being the value assigned to those not recruited). The exceptions were flexion of the little finger while recording from ring finger units (median: 40% MVC), and vice versa (median: 2% MVC). For all active-test finger combinations, only 35/181 units were activated when the active finger flexed at less than 20% MVC, and the fingers were adjacent for 28 of these. Functionally, to recruit FDS units during grasping and lifting, relatively heavy objects were required, although systematic variation occurred with the width of the object. In conclusion, FDS components can be selectively activated by volition and this may be especially important for grasping at high forces with one or more fingers.

Patient-based outcomes following surgical debridement and flap coverage of digital mucous cysts.

PubMed

Hojo, Junya; Omokawa, Shohei; Shigematsu, Koji; Onishi, Tadanobu; Murata, Keiichi; Tanaka, Yasuhito

2016-01-01

The purpose of this prospective cohort study was to evaluate patient-based outcomes and complications following excision of mucous cysts, joint debridement, and closure with one of three types of local flaps. From 2000-2011, 35 consecutive patients with 37 digital mucous cysts were treated surgically. The surgical procedure included excision of the cyst together with the attenuated skin, joint debridement on the affected side including capsulectomy, and removal of osteophytes. Depending on the size and location of the cyst, the skin defect was covered by a transposition flap (31 cysts), an advancement flap (two cysts), or a rotation flap (four cysts). At an average follow-up time of 4 years, 4 months, there was no wound infection, flap necrosis, or joint stiffness. Preoperative nail ridging resolved in seven of nine fingers, and no nail deformities developed after surgery. One cyst, treated with a transposition flap, recurred 10 months after surgery. The average satisfaction score for the affected finger significantly improved from 4.3 to 6.8, and the average pain score decreased from 4.7 to 2.3. This treatment protocol provides reliable results. Patients were satisfied with the reduction of associated pain and the postoperative appearance of the treated finger, and postoperative complications were minimal.

Computer-aided interpretation approach for optical tomographic images

NASA Astrophysics Data System (ADS)

Klose, Christian D.; Klose, Alexander D.; Netz, Uwe J.; Scheel, Alexander K.; Beuthan, Jürgen; Hielscher, Andreas H.

2010-11-01

A computer-aided interpretation approach is proposed to detect rheumatic arthritis (RA) in human finger joints using optical tomographic images. The image interpretation method employs a classification algorithm that makes use of a so-called self-organizing mapping scheme to classify fingers as either affected or unaffected by RA. Unlike in previous studies, this allows for combining multiple image features, such as minimum and maximum values of the absorption coefficient for identifying affected and not affected joints. Classification performances obtained by the proposed method were evaluated in terms of sensitivity, specificity, Youden index, and mutual information. Different methods (i.e., clinical diagnostics, ultrasound imaging, magnet resonance imaging, and inspection of optical tomographic images), were used to produce ground truth benchmarks to determine the performance of image interpretations. Using data from 100 finger joints, findings suggest that some parameter combinations lead to higher sensitivities, while others to higher specificities when compared to single parameter classifications employed in previous studies. Maximum performances are reached when combining the minimum/maximum ratio of the absorption coefficient and image variance. In this case, sensitivities and specificities over 0.9 can be achieved. These values are much higher than values obtained when only single parameter classifications were used, where sensitivities and specificities remained well below 0.8.

Finger crease pattern recognition using Legendre moments and principal component analysis

NASA Astrophysics Data System (ADS)

Luo, Rongfang; Lin, Tusheng

2007-03-01

The finger joint lines defined as finger creases and its distribution can identify a person. In this paper, we propose a new finger crease pattern recognition method based on Legendre moments and principal component analysis (PCA). After obtaining the region of interest (ROI) for each finger image in the pre-processing stage, Legendre moments under Radon transform are applied to construct a moment feature matrix from the ROI, which greatly decreases the dimensionality of ROI and can represent principal components of the finger creases quite well. Then, an approach to finger crease pattern recognition is designed based on Karhunen-Loeve (K-L) transform. The method applies PCA to a moment feature matrix rather than the original image matrix to achieve the feature vector. The proposed method has been tested on a database of 824 images from 103 individuals using the nearest neighbor classifier. The accuracy up to 98.584% has been obtained when using 4 samples per class for training. The experimental results demonstrate that our proposed approach is feasible and effective in biometrics.

Critical bending moment of four implant-abutment interface designs.

PubMed

Lee, Frank K; Tan, Keson B; Nicholls, Jack I

2010-01-01

Critical bending moment (CBM), defined as the bending moment at which the external nonaxial load applied overcomes screw joint preload and causes loss of contact between the mating surfaces of the implant screw joint components, was measured for four different implants and their single-tooth replacement abutments. CBM at the implant-abutment screw joint for four implant-abutment test groups was measured in vitro at 80%, 100%, and 120% of the manufacturers' recommended torque levels. Regular-platform implants with their corresponding single-tooth abutments were used. Microstrain was measured while known loads were applied to the abutment at known distances from the implant-abutment interface. Strain instrumentation was used to record the strain data dynamically to determine the point of gap opening. All torque applications and strain measurements were repeated five times for the five samples in each group. For the Branemark/CeraOne assemblies, the mean CBMs were 72.14 Ncm, 102.21 Ncm, and 119.13 Ncm, respectively, at 80%, 100%, and 120% of the manufacturer's recommended torque. For the Replace/Easy assemblies, mean CBMs were 86.20 Ncm, 109.92 Ncm, and 120.93 Ncm; for the Biomet 3i/STA assemblies, they were 67.97 Ncm, 83.14 Ncm, and 91.81 Ncm; and for the Lifecore/COC assemblies, they were 58.32 Ncm, 76.79 Ncm, and 78.93 Ncm. Two-way analysis of variance revealed significant effects for the test groups and torque levels. Subsequent tests confirmed that significant differences existed between test groups and torque levels. The results appear to confirm the primary role of the compressive preload imparted by the abutment screw in maintaining screw joint integrity. CBM was found to differ among implant systems and torque levels. Torque levels recommended by the manufacturer should be followed to ensure screw joint integrity.

Effect of the Coronal Wall Thickness of Dental Implants on the Screw Joint Stability in the Internal Implant-Abutment Connection.

PubMed

Lee, Ji-Hye; Huh, Yoon-Hyuk; Park, Chan-Jin; Cho, Lee-Ra

2016-01-01

To evaluate the effect of implant coronal wall thickness on load-bearing capacity and screw joint stability. Experimental implants were customized after investigation of the thinnest coronal wall thickness of commercially available implant systems with a regular platform diameter. Implants with four coronal wall thicknesses (0.2, 0.3, 0.4, and 0.5 mm) were fabricated. Three sets of tests were performed. The first set was a failure test to evaluate load-bearing capacity and elastic limit. The second and third sets were cyclic and static loading tests. After abutment screw tightening of each implant, vertical cyclic loading of 250 N or static loading from 250 to 800 N was applied. Coronal diameter expansion, axial displacement, and removal torque values of the implants were compared. Repeated measures analysis of variance (ANOVA) was used for statistical analysis (α = .05). Implants with 0.2-mm coronal wall thickness demonstrated significantly low load-bearing capacity and elastic limit (both P < .05). These implants also showed significantly large coronal diameter expansion and axial displacement after screw tightening (both P < .05). Greater vertical load and thinner coronal wall thickness significantly increased coronal diameter expansion of the implant, axial displacement of the abutment, and removal torque loss of the abutment screw (all P < .05). Implant coronal wall thickness of 0.2 mm produces significantly inferior load-bearing capacity and screw joint stability.

Limited independent flexion of the thumb and fingers in human subjects.

PubMed Central

Kilbreath, S L; Gandevia, S C

1994-01-01

1. We investigated whether human subjects can activate selectively flexor pollicis longus (FPL) and digital portions of flexor digitorum profundus (FDP). These muscles were selected because they are the only flexors of the distal phalanges. 2. Electromyographic activity (EMG) was recorded with intramuscular electrodes from one digital component of the deep flexors ('test') while subjects lifted weights by flexing the distal interphalangeal joint of the other digits in turn ('lifting' digits). Only recording sites at which single motor units were recruited selectively at low forces were used. The weights lifted represented 2.5-50% of the maximal voluntary contraction (MVC). We measured the lowest weight lifted which produced phasic and tonic coactivation in the 'test' muscle. 3. The extent of coactivation varied with the 'distance' between the test and lifting digits although no significant difference occurred in the pattern of coactivation thresholds among the digital flexors. The extent of coactivation increased when angular displacement or velocity at the distal interphalangeal joint of the lifting digit increased but was not critically dependent on restraint of the hand. 4. Because mechanical 'connections' could interfere with the ability to move a distal phalanx independently, the arms of nine cadavers were studied. The separation of tendons between the thumb (FPL) and the index portion of FDP, and between the index and middle portions of FDP, usually extended more proximally in the forearm than separation between the tendons to the middle and ring fingers and between the ring and little fingers. Direct intertendinous links were also noted. 5. It is not possible to direct a sufficiently focal motor command to flex selectively the distal joint of the fingers and thumb when forces exceeding 2.5% MVC are generated. For the middle, ring and little fingers in particular, movement of adjacent digits may also involve 'in-series' mechanical links between adjacent components of FDP. Images Figure 6 PMID:7837104

Metacarpophalangeal joint arthroscopy: indications revisited.

PubMed

Choi, Alexander K Y; Chow, Esther C S; Ho, P C; Chow, Y Y

2011-08-01

Arthroscopic surgery has become the gold standard for the diagnosis and treatment of major joint disorders. With advancement in arthroscopic technique, arthroscopy has become feasible in most human joints, even those as small as the finger joints. The metacarpophalangeal joint (MCPJ) can become spacious with simple traction, the intra-articular anatomy is simple, and its major structures can be easily visualized and identified. However, MCPJ arthroscopy has never been popular. This article describes our experience with MCPJ arthroscopy and seeks to establish its role in clinical practice. Copyright © 2011 Elsevier Inc. All rights reserved.

The Lateral Proximal Phalanx Flap for Contractures and Soft Tissue Defects in the Proximal Interphalangeal Joint

PubMed Central

Beltrán, Aldo G.; Romero, Camilo J.

2016-01-01

Background: The management of contractures and soft tissue defects in the proximal interphalangeal (PIP) finger joint remains a challenge. We report a transposition flap from the lateral skin of the proximal phalanx that is based on perforating branches of the digital arteries and can be used safely for both palmar and dorsal cover defects. Methods: We first completed an anatomic study, dissecting 20 fingers in fresh cadavers with arterial injections and made the new flap in patients with dorsal or palmar defects in PIP joints. Results: In cadavers, we can reveal 4 constant branches from each digital artery in the proximal phalanx, with the more distal just in the PIP joint constituting the flap pedicle. Between February 2010 and February 2015, we designed 33 flaps in 29 patients, 7 for dorsal and 26 for palmar defects, with no instances of flap necrosis and 4 distal epidermolysis. The patients were between 4 and 69 years with no major complications, and all of the skin defects in the PIP joint were resolved satisfactorily without any relevant sequelae at the donor site. Conclusions: This flap procedure is an easy, reliable, versatile, and safe technique, and could be an important tool for the management of difficult skin defects and contractures at the PIP joint level. PMID:28082850

Assessment of Embedded Conjugated Polymer Sensor Arrays for Potential Load Transmission Measurement in Orthopaedic Implants

PubMed Central

Micolini, Carolina; Holness, Frederick Benjamin; Johnson, James A.

2017-01-01

Load transfer through orthopaedic joint implants is poorly understood. The longer-term outcomes of these implants are just starting to be studied, making it imperative to monitor contact loads across the entire joint implant interface to elucidate the force transmission and distribution mechanisms exhibited by these implants in service. This study proposes and demonstrates the design, implementation, and characterization of a 3D-printed smart polymer sensor array using conductive polyaniline (PANI) structures embedded within a polymeric parent phase. The piezoresistive characteristics of PANI were investigated to characterize the sensing behaviour inherent to these embedded pressure sensor arrays, including the experimental determination of the stable response of PANI to continuous loading, stability throughout the course of loading and unloading cycles, and finally sensor repeatability and linearity in response to incremental loading cycles. This specially developed multi-material additive manufacturing process for PANI is shown be an attractive approach for the fabrication of implant components having embedded smart-polymer sensors, which could ultimately be employed for the measurement and analysis of joint loads in orthopaedic implants for in vitro testing. PMID:29186079

Biomechanical analysis comparing natural and alloplastic temporomandibular joint replacement using a finite element model.

PubMed

Mesnard, Michel; Ramos, Antonio; Ballu, Alex; Morlier, Julien; Cid, M; Simoes, J A

2011-04-01

Prosthetic materials and bone present quite different mechanical properties. Consequently, mandible reconstruction with metallic materials (or a mandible condyle implant) modifies the physiologic behavior of the mandible (stress, strain patterns, and condyle displacements). The changing of bone strain distribution results in an adaptation of the temporomandibular joint, including articular contacts. Using a validated finite element model, the natural mandible strains and condyle displacements were evaluated. Modifications of strains and displacements were then assessed for 2 different temporomandibular joint implants. Because materials and geometry play important key roles, mechanical properties of cortical bone were taken into account in models used in finite element analysis. The finite element model allowed verification of the worst loading configuration of the mandibular condyle. Replacing the natural condyle by 1 of the 2 tested implants, the results also show the importance of the implant geometry concerning biomechanical mandibular behavior. The implant geometry and stiffness influenced mainly strain distribution. The different forces applied to the mandible by the elevator muscles, teeth, and joint loads indicate that the finite element model is a relevant tool to optimize implant geometry or, in a subsequent study, to choose a more suitable distribution of the screws. Bone screws (number and position) have a significant influence on mandibular behavior and on implant stress pattern. Stress concentration and implant fracture must be avoided. Copyright © 2011 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Transfer of supinator motor branches to the posterior interosseous nerve in C7-T1 brachial plexus palsy.

PubMed

Bertelli, Jayme Augusto; Ghizoni, Marcos Flavio

2010-07-01

In C7-T1 palsies of the brachial plexus, shoulder and elbow function are preserved, but finger motion is absent. Finger flexion has been reconstructed by tendon or nerve transfers. Finger extension has been restored ineffectively by attaching the extensor tendons to the distal aspect of the dorsal radius (termed tenodesis) or by tendon transfers. In these palsies, supinator muscle function is preserved, because innervation stems from the C-6 root. The feasibility of transferring supinator branches to the posterior interosseous nerve has been documented in a previous anatomical study. In this paper, the authors report the clinical results of supinator motor nerve transfer to the posterior interosseous nerve in 4 patients with a C7-T1 root lesion. Four adult patients with C7-T1 root lesions underwent surgery between 5 and 7 months postinjury. The patients had preserved motion of the shoulder, elbow, and wrist, but they had complete palsy of finger motion. They underwent finger flexion reconstruction via transfer of the brachialis muscle, and finger and thumb extension were restored by transferring the supinator motor branches to the posterior interosseous nerve. This nerve transfer was performed through an incision over the proximal third of the radius. Dissection was carried out between the extensor carpi radialis brevis and the extensor digitorum communis. The patients were followed up as per regular protocol and underwent a final evaluation 12 months after surgery. To document the extent of recovery, the authors assessed the degree of active metacarpophalangeal joint extension of the long fingers. The thumb span was evaluated by measuring the distance between the thumb pulp and the lateral aspect of the index finger. Surgery to transfer the supinator motor branches to the posterior interosseous nerve was straightforward. Twelve months after surgery, all patients were capable of opening their hand and could fully extend their metacarpophalangeal joints. The distance of thumb abduction improved from 0 to 5 cm from the lateral aspect of the index finger. Transferring supinator motor nerves directly to the posterior interosseous nerve is effective in at least partially restoring thumb and finger extension in patients with lower-type injuries of the brachial plexus.

Fortifying the Bone-Implant Interface Part 2: An In Vivo Evaluation of 3D-Printed and TPS-Coated Triangular Implants.

PubMed

MacBarb, Regina F; Lindsey, Derek P; Woods, Shane A; Lalor, Peggy A; Gundanna, Mukund I; Yerby, Scott A

2017-01-01

Minimally invasive surgical fusion of the sacroiliac (SI) joint using machined solid triangular titanium plasma spray (TPS) coated implants has demonstrated positive clinical outcomes in SI joint pain patients. Additive manufactured (AM), i.e. 3D-printed, fenestrated triangular titanium implants with porous surfaces and bioactive agents, such as nanocrystalline hydroxyapatite (HA) or autograft, may further optimize bony fixation and subsequent biomechanical stability. A bilateral ovine distal femoral defect model was used to evaluate the cancellous bone-implant interfaces of TPS-coated and AM implants. Four implant groups (n=6/group/time-point) were included: 1)TPS-coated, 2)AM, 3)AM+HA, and 4)AM+Autograft. The bone-implant interfaces of 6- and 12-week specimens were investigated via radiographic, biomechanical, and histomorphometric methods. Imaging showed peri-implant bone formation around all implants. Push-out testing demonstrated forces greater than 2500 N, with no significant differences among groups. While TPS implants failed primarily at the bone-implant interface, AM groups failed within bone ~2-3mm away from implant surfaces. All implants exhibited bone ongrowth, with no significant differences among groups. AM implants had significantly more bone ingrowth into their porous surfaces than TPS-coated implants ( p <0.0001). Of the three AM groups, AM+Auto implants had the greatest bone ingrowth into the porous surface and through their core ( p <0.002). Both TPS and AM implants exhibited substantial bone ongrowth and ingrowth, with additional bone through growth into the AM implants' core. Overall, AM implants experienced significantly more bone infiltration compared to TPS implants. While HA-coating did not further enhance results, the addition of autograft fostered greater osteointegration for AM implants. Additive manufactured implants with a porous surface provide a highly interconnected porous surface that has comparatively greater surface area for bony integration. Results suggest this may prove advantageous toward promoting enhanced biomechanical stability compared to TPS-coated implants for SI joint fusion procedures.

Effectiveness of Conservative, Surgical, and Postsurgical Interventions for Trigger Finger, Dupuytren Disease, and De Quervain Disease: A Systematic Review.

PubMed

Huisstede, Bionka M; Gladdines, Saskia; Randsdorp, Manon S; Koes, Bart W

2017-08-30

To provide an evidence-based overview of the effectiveness of conservative and (post)surgical interventions for trigger finger, Dupuytren disease, and De Quervain disease. Cochrane Library, Physiotherapy Evidence Database, PubMed, Embase, and CINAHL were searched to identify relevant systematic reviews and randomized controlled trials (RCTs). Two reviewers independently applied the inclusion criteria to select potential studies. Two reviewers independently extracted the data and assessed the methodologic quality. A best-evidence synthesis was performed to summarize the results. Two reviews (trigger finger and De Quervain disease) and 37 randomized controlled trials (RCTs) (trigger finger: n=8; Dupuytren disease: n=14, and De Quervain disease: n=15) were included. The trials reported on oral medication (Dupuytren disease), physiotherapy (De Quervain disease), injections and surgical treatment (trigger finger, Dupuytren disease, and De Quervain disease), and other conservative (De Qervain disease) and postsurgical treatment (Dupuytren disease). Moderate evidence was found for the effect of corticosteroid injection on the very short term for trigger finger, De Quervain disease, and for injections with collagenase (30d) when looking at all joints, and no evidence was found when looking at the PIP joint for Dupuytren disease. A thumb splint as additive to a corticosteroid injection seems to be effective (moderate evidence) for De Quervain disease (short term and midterm). For Dupuytren disease, use of a corticosteroid injection within a percutaneous needle aponeurotomy in the midterm and tamoxifen versus a placebo before or after a fasciectomy seems to promising (moderate evidence). We also found moderate evidence for splinting after Dupuytren surgery in the short term. In recent years, more and more RCTs have been conducted to study treatment of the aforementioned hand disorders. However, more high-quality RCTs are still needed to further stimulate evidence-based practice for patients with trigger finger, Dupuytren disease, and De Quervain disease. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Do "premium" joint implants add value?: analysis of high cost joint implants in a community registry.

PubMed

Gioe, Terence J; Sharma, Amit; Tatman, Penny; Mehle, Susan

2011-01-01

Numerous joint implant options of varying cost are available to the surgeon, but it is unclear whether more costly implants add value in terms of function or longevity. We evaluated registry survival of higher-cost "premium" knee and hip components compared to lower-priced standard components. Premium TKA components were defined as mobile-bearing designs, high-flexion designs, oxidized-zirconium designs, those including moderately crosslinked polyethylene inserts, or some combination. Premium THAs included ceramic-on-ceramic, metal-on-metal, and ceramic-on-highly crosslinked polyethylene designs. We compared 3462 standard TKAs to 2806 premium TKAs and 868 standard THAs to 1311 premium THAs using standard statistical methods. The cost of the premium implants was on average approximately $1000 higher than the standard implants. There was no difference in the cumulative revision rate at 7-8 years between premium and standard TKAs or THAs. In this time frame, premium implants did not demonstrate better survival than standard implants. Revision indications for TKA did not differ, and infection and instability remained contributors. Longer followup is necessary to demonstrate whether premium implants add value in younger patient groups. Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Brandon Research, Inc. Orthopedic Implant Cooperative Research and Development Agreement (CRADA) Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Freeman, W.R.

1999-04-22

The project was a joint research effort between the U. S. Department of Energy's (DOE) Kansas City Plant (KCP) and Brandon Research, Inc. to develop ways to improve implants used for orthopedic surgery for joint replacement. The primary product produced by this study is design information, which may be used to develop implants that will improve long-term fixation and durability in the host bone environment.

A Novel Approach for Reconstruction of Finger Neurocutaneous Defect: A Sensory Reverse Dorsal Digital Artery Flap from the Neighboring Digit.

PubMed

Feng, Shi-Ming; Sun, Qing-Qing; Cheng, Jian; Wang, Ai-Guo

2017-11-01

Providing soft tissue coverage for finger neurocutaneous defects presents aesthetic and sensory challenges. A common source for reconstruction of soft tissue defects of the fingers is the same finger. However, when the donor areas are damaged by concomitant injuries, this option is not available. The present study aims to reconstruct finger neurocutaneous defects using a sensory reverse dorsal digital artery flap from the neighboring digit and to evaluate the efficacy of this technique. The study included 16 patients, with an average age of 34.9 years (range, 20-53 years) at the time of surgery, from May 2010 to June 2013. The sensory reverse dorsal digital artery flap was used in all 16 patients, who had a combination of soft tissue and digital nerve defects. The mean size of the soft tissue defects was 3.1 cm × 2.0 cm, and the mean flap size was 3.3 cm × 2.2 cm. The length of the nerve defects ranged from 1.3 to 2.5 cm (mean, 2.0 cm), which were reconstructed with dorsal branches of the proper digital nerve transfer. The active motion of the fingers (injured and donor) and the flap sensibility (static two-point discrimination) were measured. The appearance and functional recovery of the injured finger and the donor site were assessed using the Michigan Hand Outcomes Questionnaire. All flaps survived completely. No complications were reported, and no further flap debulking procedure was required. At the mean follow-up period of 24 months (range, 18-30 months), the mean static two-point discrimination was 6.5 mm (range, 5-10 mm) of the reconstructed area; the mean ranges of motions of the injured finger and the opposite finger at the proximal interphalangeal and distal interphalangeal joints were 102.2° and 103.5°, and 70.3° and 76.5°, respectively. The average ranges of motions of the metacarpophalangeal and proximal interphalangeal joints of the donor fingers were 90° and 103.4°, respectively. Based on the Michigan Hand Outcomes Questionnaire, 10 patients were strongly satisfied and 6 were satisfied with the functional recovery of the injured finger; however, 13 patients were strongly satisfied and 3 were satisfied with the appearance of the injured finger. The sensory reverse dorsal digital artery flap from the neighboring digit, based on the dorsal branch of the digital artery, is an effective and additional option for finger neurocutaneous defect reconstruction when use of the local and regional flaps is not feasible. © 2017 Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.

A pilot study to assess use of passive extension bias to facilitate finger movement for repetitive task practice after stroke.

PubMed

Iwamuro, B T; Fischer, H C; Kamper, D G

2011-01-01

The purpose of this study was to investigate whether active range of finger motion could be increased through the introduction of passive, external extension joint torques in stroke survivors. Five chronic stroke survivors with severe hand impairment resulting from hemiparesis took part in the study. Participants completed 2 experimental sessions in which hand movement and function were assessed. In one session, they wore a custom orthotic glove (X-Glove) that passively supplied extension torques to the joints of the fingers. In the second session, they performed the same tasks as in the other session, but without the glove. Outcome measures consisted of active range of motion, distance of the fingertip from the hand, selected tasks from the Graded Wolf Motor Function Test (GWMFT), and the Box and Blocks (BB) test. Primary results with and without the glove were compared using paired t tests with a Bonferroni correction. Active range of motion improved significantly by over 50%, from 4.4 cm to 6.7 cm, when the X-Glove was worn (P = .011). The distance of the fingertip from the metacarpophalangeal joint increased by an average of 2.2 cm for 4 of the subjects, although this change was not significant across all 5 subjects (P = .123). No significant differences were observed in the BB or GWMFT whether the X-Glove was worn or not. Introduction of passive extension torque can improve active range of motion for the fingers, even in chronic stroke survivors with substantial hand impairment. The increased range of motion would facilitate therapeutic training of the hand, potentially even in the home environment, although the bulk of the orthosis should be minimized to facilitate interactions with real objects.

Management of an unusual extreme extension contracture of the wrist: role of a custom-designed exercise program in achieving a good range of movement and prevention of recontraction.

PubMed

Saraiya, Hemant

2003-01-01

An extreme extension contracture of wrist with dorsal contracture of fingers 15 years after burn injury is described. Shortening of extensor tendons, secondary lengthening of flexor tendons, contracted wrist joint capsule, unusual dislocation of carpals, dorsal dislocation of metacarpophalangeal joints of fingers, and provision of sufficient amount of good-quality skin were some of the issues that had to be addressed in treatment. The contracture was released, the carpals and metacarpophalangeal joint dislocations were corrected and fixed with K wires, and the resulting defect was covered with a sheet split-thickness skin graft. An exercise program was designed that consisted of isotonic, isokinetic, and isometric resistance exercises and passive, active, and active-assistive range of motion exercises. These exercises were pursued with the intention of increasing dynamic strength, endurance, and overall functional recovery of the flexor muscles by exploiting the immature nature of early scar tissue. The resultant enhanced flexor muscle power from exercises along with the dynamic splint helped in lengthening of extensor tendons, wrist joint capsule, and split-thickness skin graft. It also helped in resisting the recontracting tendency, with further recovery of good range of wrist and fingers movements, obviating the need of tendon-lengthening surgery and flap coverage. One and half years of follow up didn't show any sign of recontracture, and the patient was able to perform his routine activities. Postburn wrist contractures of such magnitude have been seldom described. Emphasis is put on simple contracture release and a postoperative exercise program.

Treatment of mallet finger deformity with a modified palmaris longus tendon graft through a bone tunnel.

PubMed

Liu, Zengbing; Ma, Kai; Huang, Dong

2018-01-01

To investigate the clinical effect of treating mallet finger deformity using a modified palmaris longus tendon graft through a bone tunnel. Altogether, 21 patients with mallet finger deformity (16 men, 5 women; average age 31 years, range 19-47 years) were treated with a modified palmaris longus tendon graft through a bone tunnel during 18 months (2014-2016). Four index fingers, seven middle fingers, eight ring fingers, and two little fingers were treated for four cutting injuries, eleven finger sprains, four crush injuries, and two twist injuries (7 open and 14 closed injuries). Duration from injury to surgery was 9 h to 13 weeks. Three patients underwent surgery after 6 weeks of unsuccessful conservative treatment. No tendon was attached to the extensor tendon insertion in 16 patients, and 5 had residual tendon of <0.2 cm attached. All patients had distal segment flexion deformity and dorsiflexion disorder. Surgery comprised transverse penetration and vertical drilling of the base of the distal phalanx (2.0 and 2.5 mm diameter drills). Equal shallow semitendinosus pieces of the palmaris longus tendon (4 cm) were obtained from the sagittal end and were passed through a dorsal bone hole, emerging from a transverse bone hole. The two bundles were sutured to the main tendon. Tension was adjusted, and the broken ends were sutured. The distal interphalangeal joints were fixed in hyperextension. All patients were followed for 7-16 months (average 6.0 ± 0.3 months) postoperatively. All 21 patients had grade A wound healing, with no complications (e.g., necrotic wound, recurrence, joint stiffness). The mallet finger deformity was corrected with good appearance, no obvious abnormalities, and satisfactory flexion and extension. Two patients had a superficial wound infection. Each recovered after symptomatic treatment. One patient had a mild result, with limited extension. There were no recurrences. Results were evaluated according to Patel et al.'s system, which revealed 15 excellent and 5 good results (combined 95.23% rate), with 1 mild result (limited extension). Patients were satisfied with the appearance and function of the affected fingers, and the desired surgical end result was achieved. Use of this modified surgery for treating mallet finger deformity, especially with no or little tendon attached at the extensor tendon insertion, results in nearly anatomical reconstruction of the extensor tendon insertion. Its advantages include simple surgery, reliable fixation, fewer complications, and clinical efficacy.

Localization of carbon atoms and extended defects in silicon implanted separately with C+ and B+ ions and jointly with C+ and B+ ions

NASA Astrophysics Data System (ADS)

Jadan, M.; Chelyadinskii, A. R.; Odzhaev, V. B.

2013-02-01

The possibility to control the localization of implanted carbon in sites and interstices in silicon immediately during the implantation has been demonstrated. The formation of residual extended defects in silicon implanted separately with C+ and B+ ions and jointly with C+ and B+ ions has been shown. It has been found that the formation of residual defects can be suppressed due to annihilation of point defects at C atoms (the Watkins effect). The positive effect is attained if implanted carbon is localized over lattice sites, which is provided by its implantation with the effective current density of the scanning ion beam no lower than 1.0 μA cm-2.

Microscopic pick-and-place teleoperation

NASA Astrophysics Data System (ADS)

Bhatti, Pamela; Hannaford, Blake; Marbot, Pierre-Henry

1993-03-01

A three degree-of-freedom direct drive mini robot has been developed for biomedical applications. The design approach of the mini robot relies heavily upon electromechanical components from the Winchester disk drive industry. In the current design, the first joint is driven by actuators from a 5.25' drive, and the following joints are driven by actuators typical of 3.5' drives. The system has 5 - 10 micrometers of position repeatability and resolution in all three axes. A mini gripper attachment has been fabricated for the robot to explore manipulation of objects ranging from 50 micrometers to 500 micrometers . Mounted on the robot, the gripper has successfully performed pick and place operations under teleoperated control. The mini robot serves to precisely position the gripper, and a needle-like finger of the gripper deflects so the fingers can grip a target object. The gripper finger capable of motion is fabricated with a piezoelectric bimorph crystal which deflects with an applied DC voltage. The experimental results are promising, and the mini gripper may be modified for future biomedical and micro assembly applications.

Removal Torque and Biofilm Accumulation at Two Dental Implant-Abutment Joints After Fatigue.

PubMed

Pereira, Jorge; Morsch, Carolina S; Henriques, Bruno; Nascimento, Rubens M; Benfatti, Cesar Am; Silva, Filipe S; López-López, José; Souza, Júlio Cm

2016-01-01

The aim of this study was to evaluate the removal torque and in vitro biofilm penetration at Morse taper and hexagonal implant-abutment joints after fatigue tests. Sixty dental implants were divided into two groups: (1) Morse taper and (2) external hexagon implant-abutment systems. Fatigue tests on the implant-abutment assemblies were performed at a normal force (FN) of 50 N at 1.2 Hz for 500,000 cycles in growth medium containing human saliva for 72 hours. Removal torque mean values (n = 10) were measured after fatigue tests. Abutments were then immersed in 1% protease solution in order to detach the biofilms for optical density and colony-forming unit (CFU/cm²) analyses. Groups of implant-abutment assemblies (n = 8) were cross-sectioned at 90 degrees relative to the plane of the implant-abutment joints for the microgap measurement by field-emission guns scanning electron microscopy. Mean values of removal torque on abutments were significantly lower for both Morse taper (22.1 ± 0.5 μm) and external hexagon (21.1 ± 0.7 μm) abutments after fatigue tests than those recorded without fatigue tests (respectively, 24 ± 0.5 μm and 24.8 ± 0.6 μm) in biofilm medium for 72 hours (P = .04). Mean values of microgap size for the Morse taper joints were statistically signicantly lower without fatigue tests (1.7 ± 0.4 μm) than those recorded after fatigue tests (3.2 ± 0.8 μm). Also, mean values of microgap size for external hexagon joints free of fatigue were statistically signicantly lower (1.5 ± 0.4 μm) than those recorded after fatigue tests (8.1 ± 1.7 μm) (P < .05). The optical density of biofilms and CFU mean values were lower on Morse taper abutments (Abs630nm at 0.06 and 2.9 × 10⁴ CFU/cm²) than that on external hexagon abutments (Abs630nm at 0.08 and 4.5 × 10⁴ CFU/cm²) (P = .01). The mean values of removal torque, microgap size, and biofilm density recorded at Morse taper joints were lower in comparison to those recorded at external hexagon implant-abutment joints after fatigue tests in a simulated oral environment for 72 hours.

Implantable sensor technology: measuring bone and joint biomechanics of daily life in vivo

PubMed Central

2013-01-01

Stresses and strains are major factors influencing growth, remodeling and repair of musculoskeletal tissues. Therefore, knowledge of forces and deformation within bones and joints is critical to gain insight into the complex behavior of these tissues during development, aging, and response to injury and disease. Sensors have been used in vivo to measure strains in bone, intraarticular cartilage contact pressures, and forces in the spine, shoulder, hip, and knee. Implantable sensors have a high impact on several clinical applications, including fracture fixation, spine fixation, and joint arthroplasty. This review summarizes the developments in strain-measurement-based implantable sensor technology for musculoskeletal research. PMID:23369655

Gage for evaluating rheumatoid hands

NASA Technical Reports Server (NTRS)

Houge, J. C.; Plautz, K. A.

1981-01-01

Two-axis goniometer accurately measures movements of fingers about knuckle joints, diagnosing hands structurally changed by rheumatoid arthritis. Instrument measures lateral movement which is small in normal knuckles but increased in diseased joints. Goniometer is two connected protractors that simultaneously measure angles in perpindicular planes. Dials are offset to clear bony protuberances; extension and offset adjustments span any hand size.

Anatomy and Biomechanics of the Finger Proximal Interphalangeal Joint.

PubMed

Pang, Eric Quan; Yao, Jeffrey

2018-05-01

A complete understanding of the normal anatomy and biomechanics of the proximal interphalangeal joint is critical when treating pathology of the joint as well as in the design of new reconstructive treatments. The osseous anatomy dictates the principles of motion at the proximal interphalangeal joint. Subsequently, the joint is stabilized throughout its motion by the surrounding proximal collateral ligament, accessory collateral ligament, and volar plate. The goal of this article is to review the normal anatomy and biomechanics of the proximal interphalangeal joint and its associated structures, most importantly the proper collateral ligament, accessory collateral ligament, and volar plate. Copyright © 2017 Elsevier Inc. All rights reserved.

Visual and computer software-aided estimates of Dupuytren's contractures: correlation with clinical goniometric measurements.

PubMed

Smith, R P; Dias, J J; Ullah, A; Bhowal, B

2009-05-01

Corrective surgery for Dupuytren's disease represents a significant proportion of a hand surgeon's workload. The decision to go ahead with surgery and the success of surgery requires measuring the degree of contracture of the diseased finger(s). This is performed in clinic with a goniometer, pre- and postoperatively. Monitoring the recurrence of the contracture can inform on surgical outcome, research and audit. We compared visual and computer software-aided estimation of Dupuytren's contractures to clinical goniometric measurements in 60 patients with Dupuytren's disease. Patients' hands were digitally photographed. There were 76 contracted finger joints--70 proximal interphalangeal joints and six distal interphalangeal joints. The degrees of contracture of these images were visually assessed by six orthopaedic staff of differing seniority and re-assessed with computer software. Across assessors, the Pearson correlation between the goniometric measurements and the visual estimations was 0.83 and this significantly improved to 0.88 with computer software. Reliability with intra-class correlations achieved 0.78 and 0.92 for the visual and computer-aided estimations, respectively, and with test-retest analysis, 0.92 for visual estimation and 0.95 for computer-aided measurements. Visual estimations of Dupuytren's contractures correlate well with actual clinical goniometric measurements and improve further if measured with computer software. Digital images permit monitoring of contracture after surgery and may facilitate research into disease progression and auditing of surgical technique.

Dislocation

MedlinePlus

... Dislocations can occur in contact sports, such as football and hockey, and in sports in which falls ... downhill skiing, gymnastics and volleyball. Basketball players and football players also commonly dislocate joints in their fingers ...

Bulimia

MedlinePlus

... large amounts of high-calorie foods, usually in secret. During these episodes, the person feels a lack ... and pimples Small cuts and calluses across the tops of the finger joints from forcing oneself to ...

Design of a wearable hand exoskeleton for exercising flexion/extension of the fingers.

PubMed

Jo, Inseong; Lee, Jeongsoo; Park, Yeongyu; Bae, Joonbum

2017-07-01

In this paper, design of a wearable hand exoskeleton system for exercising flexion/extension of the fingers, is proposed. The exoskeleton was designed with a simple and wearable structure to aid finger motions in 1 degree of freedom (DOF). A hand grasping experiment by fully-abled people was performed to investigate general hand flexion/extension motions and the polynomial curve of general hand motions was obtained. To customize the hand exoskeleton for the user, the polynomial curve was adjusted to the joint range of motion (ROM) of the user and the optimal design of the exoskeleton structure was obtained using the optimization algorithm. A prototype divided into two parts (one part for the thumb, the other for rest fingers) was actuated by only two linear motors for compact size and light weight.

Morphology and Mobility of the Reconstructed Basilar Joint of the Pollicized Index Finger.

PubMed

Strugarek-Lecoanet, Clotilde; Chevrollier, Jérémie; Pauchard, Nicolas; Blum, Alain; Dap, François; Dautel, Gilles

2016-09-01

To evaluate outcome and function of the reconstructed basilar thumb joint after index finger pollicization in patients presenting congenital thumb deficiency. Plain radiographs and 4-dimensional dynamic volume computed tomography scan were used to evaluate the outcome of 23 pollicizations performed on 14 children between 1996 and 2009. The mean follow-up was 8 years. Patients performed continuous movements of thumb opposition during the imaging studies. Four-dimensional scan images made it possible to visualize mobility within the reconstructed joint. In 14 cases, union occurred in the metacarpal head/metacarpal base interface. In the 9 other cases, there was a nonunion at this interface. The reconstructed joint was mobile in 20 cases, including 3 in which there was also mobility at the site of the nonunion. In 3 cases in our series, mobility was present only at the site of the nonunion, between the base and the head of the second metacarpal. Remodeling and flattening out of the metacarpal head occurred in 16 of 23 cases. The transposed metacarpal head remained spherical in 7 cases. The reconstructed joint adapts, both morphologically and functionally, allowing movement on all 3 spatial planes. Existing mechanical constraints on the reconstructed joint may explain its remodeled appearance. Therapeutic IV. Copyright © 2016 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

The Lateral Proximal Phalanx Flap for Contractures and Soft Tissue Defects in the Proximal Interphalangeal Joint: An Anatomical and Clinical Study.

PubMed

Beltrán, Aldo G; Romero, Camilo J

2017-01-01

Background: The management of contractures and soft tissue defects in the proximal interphalangeal (PIP) finger joint remains a challenge. We report a transposition flap from the lateral skin of the proximal phalanx that is based on perforating branches of the digital arteries and can be used safely for both palmar and dorsal cover defects. Methods: We first completed an anatomic study, dissecting 20 fingers in fresh cadavers with arterial injections and made the new flap in patients with dorsal or palmar defects in PIP joints. Results: In cadavers, we can reveal 4 constant branches from each digital artery in the proximal phalanx, with the more distal just in the PIP joint constituting the flap pedicle. Between February 2010 and February 2015, we designed 33 flaps in 29 patients, 7 for dorsal and 26 for palmar defects, with no instances of flap necrosis and 4 distal epidermolysis. The patients were between 4 and 69 years with no major complications, and all of the skin defects in the PIP joint were resolved satisfactorily without any relevant sequelae at the donor site. Conclusions: This flap procedure is an easy, reliable, versatile, and safe technique, and could be an important tool for the management of difficult skin defects and contractures at the PIP joint level.

Selection of optimal multispectral imaging system parameters for small joint arthritis detection

NASA Astrophysics Data System (ADS)

Dolenec, Rok; Laistler, Elmar; Stergar, Jost; Milanic, Matija

2018-02-01

Early detection and treatment of arthritis is essential for a successful outcome of the treatment, but it has proven to be very challenging with existing diagnostic methods. Novel methods based on the optical imaging of the affected joints are becoming an attractive alternative. A non-contact multispectral imaging (MSI) system for imaging of small joints of human hands and feet is being developed. In this work, a numerical simulation of the MSI system is presented. The purpose of the simulation is to determine the optimal design parameters. Inflamed and unaffected human joint models were constructed with a realistic geometry and tissue distributions, based on a MRI scan of a human finger with a spatial resolution of 0.2 mm. The light transport simulation is based on a weighted-photon 3D Monte Carlo method utilizing CUDA GPU acceleration. An uniform illumination of the finger within the 400-1100 nm spectral range was simulated and the photons exiting the joint were recorded using different acceptance angles. From the obtained reflectance and transmittance images the spectral and spatial features most indicative of inflammation were identified. Optimal acceptance angle and spectral bands were determined. This study demonstrates that proper selection of MSI system parameters critically affects ability of a MSI system to discriminate the unaffected and inflamed joints. The presented system design optimization approach could be applied to other pathologies.

Fixation of revision implants is improved by a surgical technique to crack the sclerotic bone rim.

PubMed

Kold, Søren; Bechtold, Joan E; Mouzin, Olivier; Elmengaard, Brian; Chen, Xinqian; Søballe, Kjeld

2005-03-01

Revision joint replacement has poorer outcomes compared with primary joint replacement, and these poor outcomes have been associated with poorer fixation. We investigated a surgical technique done during the revision operation to improve access from the marrow space to the implant interface by locally cracking the sclerotic bone rim that forms during aseptic loosening. Sixteen implants were inserted bilaterally by distal femur articulation of the knee joint of eight dogs, using our controlled experimental model that replicates the revision setting (sclerotic bone rim, dense fibrous tissue, macrophages, elevated cytokines) by pistoning a loaded 6.0-mm implant 500 microm into the distal femur with particulate PE. At 8 weeks, one of two revision procedures was done. Both revision procedures included complete removal of the membrane, scraping, lavaging, and inserting a revision plasma-spray Ti implant. The crack revision procedure also used a splined tool to circumferentially locally perforate the sclerotic bone rim before insertion of an identical revision implant. Superior fixation was achieved with the cracking procedure in this experimental model. Revision implants inserted with the rim cracking procedure had a significantly higher pushout strength (fivefold median increase) and energy to failure (sixfold median increase), compared with the control revision procedure. Additional evaluation is needed of local perforation of sclerotic bone rim as a simple bone-sparing means to improve revision implant fixation and thereby increase revision implant longevity.

Balancing a force on the fingertip of a two-dimensional finger model without intrinsic muscles.

PubMed

Spoor, C W

1983-01-01

A slightly flexed human middle finger can balance an external force on the fingertip. Internal stabilization is also possible, which means that the externally unloaded finger can be kept stiff. We want to analyse whether in these situations the intrinsic hand muscles are needed. Distances from tendons to flexion axes are taken from the literature and are substituted in the moment equilibrium equations of a two-dimensional finger model. Diagrams illustrate the statically indeterminate problem of solving tendon forces. The possibilities for equilibrium without intrinsics appear to depend mainly on four tendon-to-joint distances. These distances determine to which of two groups a finger belongs: (1) one in which intrinsics are not necessary for internal stabilization nor for balancing a force on the fingertip in any direction in the sagittal plane; (2) one in which, without intrinsics, internal stabilization is impossible and only dorso-distally directed forces on the fingertip can be balanced.

Medial Elbow Joint Space Increases With Valgus Stress and Decreases When Cued to Perform A Maximal Grip Contraction.

PubMed

Pexa, Brett S; Ryan, Eric D; Myers, Joseph B

2018-04-01

Previous research indicates that the amount of valgus torque placed on the elbow joint during overhead throwing is higher than the medial ulnar collateral ligament (UCL) can tolerate. Wrist and finger flexor muscle activity is hypothesized to make up for this difference, and in vitro studies that simulated activity of upper extremity musculature, specifically the flexor digitorum superficialis and flexor carpi ulnaris, support this hypothesis. To assess the medial elbow joint space at rest, under valgus stress, and under valgus stress with finger and forearm flexor contraction by use of ultrasonography in vivo. Controlled laboratory study. Participants were 22 healthy males with no history of elbow dislocation or UCL injury (age, 21.25 ± 1.58 years; height, 1.80 ± 0.08 m; weight, 79.43 ± 18.50 kg). Medial elbow joint space was measured by use of ultrasonography during 3 separate conditions: at rest (unloaded), under valgus load (loaded), and with a maximal grip contraction under a valgus load (loaded-contracted) in both limbs. Participants lay supine with their arm abducted 90° and elbow flexed 30° with the forearm in full supination. A handgrip dynamometer was placed in the participants' hand to grip against during the contracted condition. Images were reduced in ImageJ to assess medial elbow joint space. A 2-way (condition × limb) repeated-measures analysis of variance and Cohen's d effect sizes were used to assess changes in medial elbow joint space. Post hoc testing was performed with a Bonferroni adjustment to assess changes within limb and condition. The medial elbow joint space was significantly larger in the loaded condition (4.91 ± 1.16 mm) compared with the unloaded condition (4.26 ± 1.23 mm, P < .001, d = 0.712) and the loaded-contracted condition (3.88 ± 0.94 mm, P < .001, d = 1.149). No significant change was found between the unloaded and loaded-contracted conditions ( P = .137). Medial elbow joint space increases under a valgus load and then decreases when a maximal grip contraction is performed. This indicates that wrist and finger flexor muscle contraction may assist in limiting medial elbow joint space, a result similar to findings of previous research in vitro. Muscle activation of the upper extremity limits the medial elbow joint space, suggesting that injury prevention programs for throwing athletes should incorporate exercises for the elbow, wrist, and hand to limit excessive medial elbow joint space gapping during activities that create high valgus load.

Human knee joint anatomy revisited: morphometry in the light of sex-specific total knee arthroplasty.

PubMed

Dargel, Jens; Michael, Joern W P; Feiser, Janna; Ivo, Roland; Koebke, Juergen

2011-04-01

This study investigates differences in the anatomy of male and female knee joints to contribute to the current debate on sex-specific total knee implants. Morphometric data were obtained from 60 human cadaver knees, and sex differences were calculated. All data were corrected for height, and male and female specimens presenting with an identical length of the femur were analyzed as matched pairs. Male linear knee joint dimensions were significantly larger when compared with females. When corrected for differences in height, medial-lateral dimensions of male knees were significantly larger than female; however, matched paired analysis did not prove these differences to be consistent. Although implant design should focus interindividual variations in knee joint anatomy, our data do not support the concept of a female-specific implant design. Copyright © 2011 Elsevier Inc. All rights reserved.

Effects of the implant design on peri-implant bone stress and abutment micromovement: three-dimensional finite element analysis of original computer-aided design models.

PubMed

Yamanishi, Yasufumi; Yamaguchi, Satoshi; Imazato, Satoshi; Nakano, Tamaki; Yatani, Hirofumi

2014-09-01

Occlusal overloading causes peri-implant bone resorption. Previous studies examined stress distribution in alveolar bone around commercial implants using three-dimensional (3D) finite element analysis. However, the commercial implants contained some different designs. The purpose of this study is to reveal the effect of the target design on peri-implant bone stress and abutment micromovement. Six 3D implant models were created for different implant-abutment joints: 1) internal joint model (IM); 2) external joint model (EM); 3) straight abutment (SA) shape; 4) tapered abutment (TA) shapes; 5) platform switching (PS) in the IM; and 6) modified TA neck design (reverse conical neck [RN]). A static load of 100 N was applied to the basal ridge surface of the abutment at a 45-degree oblique angle to the long axis of the implant. Both stress distribution in peri-implant bone and abutment micromovement in the SA and TA models were analyzed. Compressive stress concentrated on labial cortical bone and tensile stress on the palatal side in the EM and on the labial side in the IM. There was no difference in maximum principal stress distribution for SA and TA models. Tensile stress concentration was not apparent on labial cortical bone in the PS model (versus IM). Maximum principal stress concentrated more on peri-implant bone in the RN than in the TA model. The TA model exhibited less abutment micromovement than the SA model. This study reveals the effects of the design of specific components on peri-implant bone stress and abutment displacement after implant-supported single restoration in the anterior maxilla.

Effect of adhesive stiffness and thickness on stress distributions in structural finger joints

Treesearch

Leslie H. Groom; Robert J. Leichti

1994-01-01

Environmental, political. and socioeconomic actions over the past several years have resulted in a decreased wood supply at a time when there is an increased demand for forest products. This combination of increased demand and decreased supply has forced more emphasis on engineered wood products, a varied category usually connected with adhesively-bonded end joints, of...

Effect of adhesive stiffness and thickness on stress distributions in structural finger joints

Treesearch

Leslie H. Groom; Robert J. Leichti

1994-01-01

Environmental, political, and socioeconomic actions over the past several years have resulted in a decreased wood supply at a time when there is an increased demand for forest products. This combination of increased demand and decreased supply has forced more emphasis on engineered wood products, a varied category usually connected with adhesively-bonded end joints, of...

Fortifying the Bone-Implant Interface Part 2: An In Vivo Evaluation of 3D-Printed and TPS-Coated Triangular Implants

PubMed Central

Lindsey, Derek P.; Woods, Shane A.; Lalor, Peggy A.; Gundanna, Mukund I.; Yerby, Scott A.

2017-01-01

Background Minimally invasive surgical fusion of the sacroiliac (SI) joint using machined solid triangular titanium plasma spray (TPS) coated implants has demonstrated positive clinical outcomes in SI joint pain patients. Additive manufactured (AM), i.e. 3D-printed, fenestrated triangular titanium implants with porous surfaces and bioactive agents, such as nanocrystalline hydroxyapatite (HA) or autograft, may further optimize bony fixation and subsequent biomechanical stability. Methods A bilateral ovine distal femoral defect model was used to evaluate the cancellous bone-implant interfaces of TPS-coated and AM implants. Four implant groups (n=6/group/time-point) were included: 1)TPS-coated, 2)AM, 3)AM+HA, and 4)AM+Autograft. The bone-implant interfaces of 6- and 12-week specimens were investigated via radiographic, biomechanical, and histomorphometric methods. Results Imaging showed peri-implant bone formation around all implants. Push-out testing demonstrated forces greater than 2500 N, with no significant differences among groups. While TPS implants failed primarily at the bone-implant interface, AM groups failed within bone ~2-3mm away from implant surfaces. All implants exhibited bone ongrowth, with no significant differences among groups. AM implants had significantly more bone ingrowth into their porous surfaces than TPS-coated implants (p<0.0001). Of the three AM groups, AM+Auto implants had the greatest bone ingrowth into the porous surface and through their core (p<0.002). Conclusions Both TPS and AM implants exhibited substantial bone ongrowth and ingrowth, with additional bone through growth into the AM implants’ core. Overall, AM implants experienced significantly more bone infiltration compared to TPS implants. While HA-coating did not further enhance results, the addition of autograft fostered greater osteointegration for AM implants. Clinical Relevance Additive manufactured implants with a porous surface provide a highly interconnected porous surface that has comparatively greater surface area for bony integration. Results suggest this may prove advantageous toward promoting enhanced biomechanical stability compared to TPS-coated implants for SI joint fusion procedures. PMID:28765800

The Future of Biologic Coatings for Orthopaedic Implants

PubMed Central

Goodman, Stuart B.; Yao, Zhenyu; Keeney, Michael; Yang, Fan

2013-01-01

Implants are widely used for othopaedic applications such as fixing fractures, repairing nonunions, obtaining a joint arthrodesis, total joint arthroplasty, spinal reconstruction, and soft tissue anchorage. Previously, orthopaedic implants were designed simply as mechanical devices; the biological aspects of the implant were a byproduct of stable internal/external fixation of the device to the surrounding bone or soft tissue. More recently, biologic coatings have been incorporated into orthopaedic implants in order to modulate the surrounding biological environment. This opinion article reviews current and potential future use of biologic coatings for orthopaedic implants to facilitate osseointegration and mitigate possible adverse tissue responses including the foreign body reaction and implant infection. While many of these coatings are still in the preclinical testing stage, bioengineers, material scientists and surgeons continue to explore surface coatings as a means of improving clinical outcome of patients undergoing orthopaedic surgery. PMID:23391496

Embodiment and Manipulation Learning Process for a Humanoid Hand.

DTIC Science & Technology

1995-05-01

Figures 1-1 Human somatotopic mappings 16 1-2 Human anatomy terminology 18 2-1 A picture of Cog 24 2-2 A picture of Cog’s hand 27 3-1 A... human anatomy terminologies shown in Figure 1-2 [24]. The mechanical hand constructed for this thesis have three fingers, each having two segments...and two joints, and a thumb with one segment and a joint, so the terms 18 CHAPTER 1. INTRODUCTION Saddle-joint of the thumb Figure 1-2: Human

Experience of Soviet Medicine in a Great Patriotic War, 1941-1945. Volume 16, Section 4.

DTIC Science & Technology

1980-10-22

Rotor function in the elbow, wrist joint and in the fingers/pins. In spite of energetic treatment by physiotherapy and therapeutic gymnastics , remained...the radiocarpal and elbow joint is removed by therapeutic gymnastics . It is discharged after 84 days (4/11 1943) with a good anatomical and functional...military service, it returned home into Moscow. on the arrival into nosco knee joint did not fold. Injured person itself dealt by gymnastics and in a

Erbium--169 versus triamcinolone hexacetonide in the treatment of rheumatoid finger joints.

PubMed Central

Ruotsi, A; Hypén, M; Rekonen, A; Oka, M

1979-01-01

Erbium--169 was compared with triamcinolone hexacetonide in the topical treatment of 32 patients suffering from rheumatoid arthritis. Erbium--169 was injected into 83 and triamcinolone hexacetonide into 54 proximal interphalangeal or metacarpophalangeal joints. Both treatments produced alleviation of joint pain and swelling and improvement of grip strength. At every check-up (1--18 months) the percentage of remissions was higher after triamcinolone hexacetonide injection than after erbium--169. The difference was significant at 1, 3, and 6 months. PMID:434946

The joint Simon effect depends on perceived agency, but not intentionality, of the alternative action

PubMed Central

Stenzel, Anna; Dolk, Thomas; Colzato, Lorenza S.; Sellaro, Roberta; Hommel, Bernhard; Liepelt, Roman

2014-01-01

A co-actor's intentionality has been suggested to be a key modulating factor for joint action effects like the joint Simon effect (JSE). However, in previous studies intentionality has often been confounded with agency defined as perceiving the initiator of an action as being the causal source of the action. The aim of the present study was to disentangle the role of agency and intentionality as modulating factors of the JSE. In Experiment 1, participants performed a joint go/nogo Simon task next to a co-actor who either intentionally controlled a response button with own finger movements (agency+/intentionality+) or who passively placed the hand on a response button that moved up and down on its own as triggered by computer signals (agency−/intentionality−). In Experiment 2, we included a condition in which participants believed that the co-actor intentionally controlled the response button with a Brain-Computer Interface (BCI) while placing the response finger clearly besides the response button, so that the causal relationship between agent and action effect was perceptually disrupted (agency−/intentionality+). As a control condition, the response button was computer controlled while the co-actor placed the response finger besides the response button (agency−/intentionality−). Experiment 1 showed that the JSE is present with an intentional co-actor and causality between co-actor and action effect, but absent with an unintentional co-actor and a lack of causality between co-actor and action effect. Experiment 2 showed that the JSE is absent with an intentional co-actor, but no causality between co-actor and action effect. Our findings indicate an important role of the co-actor's agency for the JSE. They also suggest that the attribution of agency has a strong perceptual basis. PMID:25140144

The joint Simon effect depends on perceived agency, but not intentionality, of the alternative action.

PubMed

Stenzel, Anna; Dolk, Thomas; Colzato, Lorenza S; Sellaro, Roberta; Hommel, Bernhard; Liepelt, Roman

2014-01-01

A co-actor's intentionality has been suggested to be a key modulating factor for joint action effects like the joint Simon effect (JSE). However, in previous studies intentionality has often been confounded with agency defined as perceiving the initiator of an action as being the causal source of the action. The aim of the present study was to disentangle the role of agency and intentionality as modulating factors of the JSE. In Experiment 1, participants performed a joint go/nogo Simon task next to a co-actor who either intentionally controlled a response button with own finger movements (agency+/intentionality+) or who passively placed the hand on a response button that moved up and down on its own as triggered by computer signals (agency-/intentionality-). In Experiment 2, we included a condition in which participants believed that the co-actor intentionally controlled the response button with a Brain-Computer Interface (BCI) while placing the response finger clearly besides the response button, so that the causal relationship between agent and action effect was perceptually disrupted (agency-/intentionality+). As a control condition, the response button was computer controlled while the co-actor placed the response finger besides the response button (agency-/intentionality-). Experiment 1 showed that the JSE is present with an intentional co-actor and causality between co-actor and action effect, but absent with an unintentional co-actor and a lack of causality between co-actor and action effect. Experiment 2 showed that the JSE is absent with an intentional co-actor, but no causality between co-actor and action effect. Our findings indicate an important role of the co-actor's agency for the JSE. They also suggest that the attribution of agency has a strong perceptual basis.

Biomechanical Analysis of Implanted Clavicle Hook Plates With Different Implant Depths and Materials in the Acromioclavicular Joint: A Finite Element Analysis Study.

PubMed

Lee, Cheng-Hung; Shih, Cheng-Min; Huang, Kui-Chou; Chen, Kun-Hui; Hung, Li-Kun; Su, Kuo-Chih

2016-11-01

Clinical implantation of clavicle hook plates is often used as a treatment for acromioclavicular joint dislocation. However, it is not uncommon to find patients that have developed acromion osteolysis or had peri-implant fracture after hook plate fixation. With the aim of preventing complications or fixation failure caused by implantation of inappropriate clavicle hook plates, the present study investigated the biomechanics of clavicle hook plates made of different materials and with different hook depths in treating acromioclavicular joint dislocation, using finite element analysis (FEA). This study established four parts using computer models: the clavicle, acromion, clavicle hook plate, and screws, and these established models were used for FEA. Moreover, implantations of clavicle hook plates made of different materials (stainless steel and titanium alloy) and with different depths (12, 15, and 18 mm) in patients with acromioclavicular joint dislocation were simulated in the biomechanical analysis. The results indicate that deeper implantation of the clavicle hook plate reduces stress on the clavicle, and also reduces the force applied to the acromion by the clavicle hook plate. Even though a clavicle hook plate made of titanium alloy (a material with a lower Young's modulus) reduces the force applied to the acromion by the clavicle hook plate, slightly higher stress on the clavicle may occur. The results obtained in this study provide a better reference for orthopedic surgeons in choosing different clavicle hook plates for surgery. Copyright © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Interdependency of the maximum range of flexion-extension of hand metacarpophalangeal joints.

PubMed

Gracia-Ibáñez, V; Vergara, M; Sancho-Bru, J-L

2016-12-01

Mobility of the fingers metacarpophalangeal (MCP) joints depends on the posture of the adjacent ones. Current Biomechanical hand models consider fixed ranges of movement at joints, regardless of the posture, thus allowing for non-realistic postures, generating wrong results in reach studies and forward dynamic analyses. This study provides data for more realistic hand models. The maximum voluntary extension (MVE) and flexion (MVF) of different combinations of MCP joints were measured covering their range of motion. Dependency of the MVF and MVE on the posture of the adjacent MCP joints was confirmed and mathematical models obtained through regression analyses (RMSE 7.7°).

The KineSpring® Knee Implant System: an implantable joint-unloading prosthesis for treatment of medial knee osteoarthritis

PubMed Central

Clifford, Anton G; Gabriel, Stefan M; O’Connell, Mary; Lowe, David; Miller, Larry E; Block, Jon E

2013-01-01

Symptomatic medial compartment knee osteoarthritis (OA) is the leading cause of musculoskeletal pain and disability in adults. Therapies intended to unload the medial knee compartment have yielded unsatisfactory results due to low patient compliance with conservative treatments and high complication rates with surgical options. There is no widely available joint-unloading treatment for medial knee OA that offers clinically important symptom alleviation, low complication risk, and high patient acceptance. The KineSpring® Knee Implant System (Moximed, Inc, Hayward, CA, USA) is a first-of-its-kind, implantable, extra-articular, extra-capsular prosthesis intended to alleviate knee OA-related symptoms by reducing medial knee compartment loading while overcoming the limitations of traditional joint-unloading therapies. Preclinical and clinical studies have demonstrated excellent prosthesis durability, substantial reductions in medial compartment and total joint loads, and clinically important improvements in OA-related pain and function. The purpose of this report is to describe the KineSpring System, including implant characteristics, principles of operation, indications for use, patient selection criteria, surgical technique, postoperative care, preclinical testing, and clinical experience. The KineSpring System has potential to bridge the gap between ineffective conservative treatments and irreversible surgical interventions for medial compartment knee OA. PMID:23717052

Functionally deficient mesenchymal stem cells reside in the bone marrow niche with M2-macrophages and amyloid-β protein adjacent to loose total joint implants.

PubMed

Margulies, Bryan S; DeBoyace, Sean D; Parsons, Adrienne M; Policastro, Connor G; Ee, Jessica S S; Damron, Timothy S

2015-05-01

We sought to demonstrate whether there is a difference in the local mesenchymal stem cells (MSC) niche obtained from patients undergoing their first total joint replacement surgery versus those patients undergoing a revision surgery for an failing total joint implant. Bone marrow aspirates collected from patients undergoing revision total joint arthroplasty were observed to be less clonal and the expression of PDGFRα, CD51, ALCAM, endoglin, CXCL12, nestin, and nucleostemin were decreased. Revision MSC were also less able to commit to an osteoblast-lineage or an adipocyte-lineage. Further, in revision MSC, OPG, and IL6 expression were increased. Monocytes, derived from revision whole marrow aspirates, were less capable of differentiating into osteoclasts, the cells implicated in the pathologic degradation of bone. Osteoclasts were also not observed in tissue samples collected adjacent to the implants of revision patients; however, the alternatatively activated M2-macrophage phenotype was observed in parallel with pathologic accumulations of amyloid-β, τ-protien and 3-nitrotyrosine. Despite the limited numbers of patients examined, our data suggest that nucleostemin may be a useful functional marker for MSC while the observation of M2-macrophage infiltration around the implant lays the foundation for future investigation into a novel mechanism that we propose is associated with loose total joint implants. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Power Doppler sonography and pulse-inversion harmonic imaging in evaluation of rheumatoid arthritis synovitis.

PubMed

Schueller-Weidekamm, Claudia; Krestan, Christian; Schueller, Gerd; Kapral, Theresa; Aletaha, Daniel; Kainberger, Franz

2007-02-01

This study evaluates the value of contrast-enhanced pulse-inversion harmonic imaging (PIHI) to detect synovial vascularization and thus the therapeutic effects of prednisolone treatment on the inflammation in finger joints in rheumatoid arthritis (RA). Before and after 7 days of mid- to high-dose steroid therapy, blood tests and clinical and sonographic examinations were assessed in 14 patients. Two hundred eighty finger joints (metacarpophalangeal [MCP] I-V, interphalangeal [IP], and proximal interphalangeal [PIP] II-V) were investigated on power Doppler sonography to determine, in each patient, the finger joint with the strongest hypervascularization and to score the synovial vascularization. Further dynamic examination of the selected joint was performed on PIHI after i.v. administration of a second-generation sonographic contrast medium. Vascularization was quantified by calculating the area under the time-intensity curves. The changes in signal intensities before and after therapy were correlated with clinical examinations (disease activity score [DAS]). The score of the joint with the strongest hypervascularization assessed by power Doppler sonography decreased significantly from 1.7 to 1.3 (p < 0.01); however, in six patients, no change was assessed after steroid therapy. In all patients, a significant reduction in PIHI signals was observed after therapy (p < 0.05). The baseline and follow-up median values of the area under the time-intensity curves were 8.56 +/- 1.28 and 7.65 +/- 0.66, respectively. The median values of the DAS decreased significantly from 4.90 +/- 0.86 to 3.6 +/- 1.0 (p < 0.01) 7 days after the steroid therapy. PIHI and power Doppler sonography enable the detection of synovial perfusion alterations after steroid therapy and, therefore, may be useful tools for the evaluation of active inflammation in RA and for the assessment of therapeutic response. However, minor changes of synovial vascularization can be better detected on PIHI than on power Doppler sonography.

Quantification of in vitro wear of a synthetic meniscus implant using gravimetric and micro-CT measurements.

PubMed

Elsner, Jonathan J; Shemesh, Maoz; Shefy-Peleg, Adaya; Gabet, Yankel; Zylberberg, Eyal; Linder-Ganz, Eran

2015-09-01

A synthetic meniscus implant was recently developed for the treatment of patients with mild to moderate osteoarthritis with knee pain associated with medial joint overload. The implant is distinctively different from most orthopedic implants in its pliable construction, and non-anchored design, which enables implantation through a mini-arthrotomy without disruption to the bone, cartilage, and ligaments. Due to these features, it is important to show that the material and design can withstand knee joint conditions. This study evaluated the long-term performance of this device by simulating loading for a total of 5 million gait cycles (Mc), corresponding to approximately five years of service in-vivo. All five implants remained in good condition and did not dislodge from the joint space during the simulation. Mild abrasion was detected by electron microscopy, but µ-CT scans of the implants confirmed that the damage was confined to the superficial surfaces. The average gravimetric wear rate was 14.5 mg/Mc, whereas volumetric changes in reconstructed µ-CT scans point to an average wear rate of 15.76 mm(3)/Mc (18.8 mg/Mc). Particles isolated from the lubricant had average diameter of 15 µm. The wear performance of this polycarbonate-urethane meniscus implant concept under ISO-14243 loading conditions is encouraging. Copyright © 2015 Elsevier Ltd. All rights reserved.

Crooked fingers and sparse hair: an interesting case of trichorhinophalangeal syndrome type 1.

PubMed

Narayanan, Ramakrishna; Chennareddy, Srinivasa

2015-01-27

Trichorhinophalangeal syndrome type 1 is a rare skeletal dysplasia of autosomal-dominant inheritance due to defects in the TRPS-1 gene. The syndrome is characterised by sparse slow-growing hair, a bulbous pear-shaped nose, cone-shaped epiphyses and deformities of the interphalangeal joints resembling those in rheumatoid arthritis. We present a case of trichorhinophalangeal syndrome in a 23-year-old man who presented with symmetrical painless progressive deformity of the fingers in both hands. 2015 BMJ Publishing Group Ltd.

Modernization of the Air Expeditionary Squadron AMAL 0960

DTIC Science & Technology

2012-07-25

to other organism not classified 1 682.9 Cellulitis and abscess of unspecified parts 2 078.1 Viral warts 1 719.41 Pain in joint shoulder 3...and strains of sacroiliac region 1 611.7 Breast lump 1 847.2 Sprain lumbar region 1 681 Cellulitis and abscess of finger and toe 2 873.4 Open...wound of face without mention of complication 1 682.6 Cellulitis and abscess of leg except foot 1 883.0 Open wound of fingers without

Grasp planning under uncertainty

NASA Technical Reports Server (NTRS)

Erkmen, A. M.; Stephanou, H. E.

1989-01-01

The planning of dexterous grasps for multifingered robot hands operating in uncertain environments is covered. A sensor-based approach to the planning of a reach path prior to grasping is first described. An on-line, joint space finger path planning algorithm for the enclose phase of grasping was then developed. The algorithm minimizes the impact momentum of the hand. It uses a Preshape Jacobian matrix to map task-level hand preshape requirements into kinematic constraints. A master slave scheme avoids inter-finger collisions and reduces the dimensionality of the planning problem.

Reduced servo-control of fatigued human finger extensor and flexor muscles.

PubMed Central

Hagbarth, K E; Bongiovanni, L G; Nordin, M

1995-01-01

1. In healthy human subjects holding the index finger semi-extended at the metacarpophalangeal joint against a moderate load, electromyographic (EMG) activity was recorded from the finger extensor and flexor muscles during different stages of muscle fatigue. The aim was to study the effect of muscle fatigue on the level of background EMG activity and on the reflex responses to torque pulses causing sudden extensor unloadings. Paired comparisons were made between the averaged EMG and finger deflection responses under two conditions: (1) at a stage of fatigue (following a sustained co-contraction) when great effort was required to maintain the finger position, and (2) under non-fatigue conditions while the subject tried to produce similar background EMG levels to those in the corresponding fatigue trials. 2. Both the unloading reflex in the extensor and the concurrent stretch reflex in the flexor were significantly less pronounced and had a longer latency in the fatigue trials. Consequently, the finger deflections had a larger amplitude and were arrested later in the fatigue trials. 3. It is concluded that--with avoidance of 'automatic gain compensation', i.e. reflex modifications attributable to differences in background EMG levels--the servo-like action of the unloading and stretch reflexes is reduced in fatigued finger extensor and flexor muscles. PMID:7562624

3-T direct MR arthrography of the wrist: value of finger trap distraction to assess intrinsic ligament and triangular fibrocartilage complex tears.

PubMed

Cerny, Milena; Marlois, Romain; Theumann, Nicolas; Bollmann, Christof; Wehrli, Laurent; Richarme, Delphine; Meuli, Reto; Becce, Fabio

2013-10-01

To determine the value of applying finger trap distraction during direct MR arthrography of the wrist to assess intrinsic ligament and triangular fibrocartilage complex (TFCC) tears. Twenty consecutive patients were prospectively investigated by three-compartment wrist MR arthrography. Imaging was performed with 3-T scanners using a three-dimensional isotropic (0.4 mm) T1-weighted gradient-recalled echo sequence, with and without finger trap distraction (4 kg). In a blind and independent fashion, two musculoskeletal radiologists measured the width of the scapholunate (SL), lunotriquetral (LT) and ulna-TFC (UTFC) joint spaces. They evaluated the amount of contrast medium within these spaces using a four-point scale, and assessed SL, LT and TFCC tears, as well as the disruption of Gilula's carpal arcs. With finger trap distraction, both readers found a significant increase in width of the SL space (mean Δ = +0.1mm, p ≤ 0.040), and noticed more contrast medium therein (p ≤ 0.035). In contrast, the differences in width of the LT (mean Δ = +0.1 mm, p ≥ 0.057) and UTFC (mean Δ = 0mm, p ≥ 0.728) spaces, as well as the amount of contrast material within these spaces were not statistically significant (p = 0.607 and ≥ 0.157, respectively). Both readers detected more SL (Δ = +1, p = 0.157) and LT (Δ = +2, p = 0.223) tears, although statistical significance was not reached, and Gilula's carpal arcs were more frequently disrupted during finger trap distraction (Δ = +5, p = 0.025). The application of finger trap distraction during direct wrist MR arthrography may enhance both detection and characterisation of SL and LT ligament tears by widening the SL space and increasing the amount of contrast within the SL and LT joint spaces. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

[Partial replacement of the knee joint with patient-specific instruments and implants (ConforMIS iUni, iDuo)].

PubMed

Beckmann, J; Steinert, A; Zilkens, C; Zeh, A; Schnurr, C; Schmitt-Sody, M; Gebauer, M

2016-04-01

Knee arthroplasty is a successful standard procedure in orthopedic surgery; however, approximately 20 % of patients are dissatisfied with the clinical results as they suffer pain and can no longer achieve the presurgery level of activity. According to the literature the reasons are inexact fitting of the prosthesis or too few anatomically formed implants resulting in less physiological kinematics of the knee joint. Reducing the number of dissatisfied patients and the corresponding number of revisions is an important goal considering the increasing need for artificial joints. In this context, patient-specific knee implants are an obvious alternative to conventional implants. For the first time implants are now matched to the individual bone and not vice versa to achieve the best possible individual situation and geometry and more structures (e.g. ligaments and bone) are preserved or only those structures are replaced which were actually destroyed by arthrosis. According to the authors view, this represents an optimal and pioneering addition to conventional implants. Patient-specific implants and the instruments needed for correct alignment and fitting can be manufactured by virtual 3D reconstruction and 3D printing based on computed tomography (CT) scans. The portfolio covers medial as well as lateral unicondylar implants, medial as well as lateral bicompartmental implants (femorotibial and patellofemoral compartments) and cruciate ligament-preserving as well as cruciate ligament-substituting total knee replacements; however, it must be explicitly emphasized that the literature is sparse and no long-term data are available.

Knee Osteoarthritis Treatment with the KineSpring Knee Implant System: A Report of Two Cases

PubMed Central

Hayes, David A.; Miller, Larry E.; Block, Jon E.

2012-01-01

Osteoarthritis (OA) is a leading cause of disability in middle-aged and older adults with the prevalence expected to increase by 40% by 2025. This dramatic projected increase in OA reflects, in large part, the alarming obesity epidemic. Indeed, it is now well understood that abnormal loading across the knee joint due to malalignment and/or excessive weight gain is responsible for accelerating OA progression. Consequently, there is a therapeutic need for alternative knee OA treatments that directly address joint overload to fill the gap between ineffective conservative care and invasive joint-modifying surgical procedures. We describe two cases that presented with bilateral knee OA resistant to conservative treatments, each with one knee previously and unsuccessfully treated with high tibial osteotomy to improve alignment and the contralateral knee successfully treated with a joint-preserving, load-absorbing implant (KineSpring Knee Implant System). PMID:23304590

Vancomycin-Rifampin Combination Therapy Has Enhanced Efficacy against an Experimental Staphylococcus aureus Prosthetic Joint Infection

PubMed Central

Niska, Jared A.; Shahbazian, Jonathan H.; Ramos, Romela Irene; Francis, Kevin P.; Bernthal, Nicholas M.

2013-01-01

Treatment of prosthetic joint infections often involves a two-stage exchange, with implant removal and antibiotic spacer placement followed by systemic antibiotic therapy and delayed reimplantation. However, if antibiotic therapy can be improved, one-stage exchange or implant retention may be more feasible, thereby decreasing morbidity and preserving function. In this study, a mouse model of prosthetic joint infection was used in which Staphylococcus aureus was inoculated into a knee joint containing a surgically placed metallic implant extending from the femur. This model was used to evaluate whether combination therapy of vancomycin plus rifampin has increased efficacy compared with vancomycin alone against these infections. On postoperative day 7, vancomycin with or without rifampin was administered for 6 weeks with implant retention. In vivo bioluminescence imaging, ex vivo CFU enumeration, X-ray imaging, and histologic analysis were carried out. We found that there was a marked therapeutic benefit when vancomycin was combined with rifampin compared with vancomycin alone. Taken together, our results suggest that the mouse model used could serve as a valuable in vivo preclinical model system to evaluate and compare efficacies of antibiotics and combinatory therapy for prosthetic joint infections before more extensive studies are carried out in human subjects. PMID:23917317

Optimal area of lateral mass mini-screws implanted in plated cervical laminoplasty: a radiography anatomy study.

PubMed

Chen, Hua; Li, Huibo; Deng, Yuxiao; Rong, Xin; Gong, Quan; Li, Tao; Song, Yueming; Liu, Hao

2017-04-01

Lateral mass mini-screws used in plated cervical laminoplasty might penetrate into facet joints. The objective is to observe this complication incidence and to identify the optimal areas for 5- and 7-mm-long mini-screws to implant on lateral mass. 47 patients who underwent plated cervical laminoplasty were included. The optimal area for mini-screws implanting was set according to pre-operative 3D CT reconstruction data. Then, each posterior-lateral mass surface was divided into three regions: 7-mm region, 5-mm region, and dangerous area. The mini-screw implanted region was recorded. Post-operative CT images were used to identify whether the mini-screws penetrated into facet joints. 235 mini-plates and 470 lateral mass mini-screws were used in the study. 117 (24.9%) mini-screws penetrated 88 (37.4%) facet joints. The 5-mm-long mini-screw optimal area occupied the upper 72, 65, 65, 64, and 65 % area of the posterior-lateral mass surface for C3-7, while the 7-mm-long mini-screw optimal area encompassed the upper 54, 39, 40, 33, and 32 %. Only 7-mm-long mini-screws were used to fix the plate to the lateral mass. 4 of 240 mini-screws in 7-mm region, 67 of the 179 mini-screws in 5-mm region, and 46 of the 51 mini-screws in dangerous region penetrated into the facet joint. The differences in the rate of facet joint penetration related to region were statistically significant (P < 0.001). The facet joint destruction by mini-screws was not a rare complication in plated cervical laminoplasty. The optimal areas we proposed may help guide the mini-screw implantation positions.

Sensing and Force-Feedback Exoskeleton (SAFE) Robotic Glove.

PubMed

Ben-Tzvi, Pinhas; Ma, Zhou

2015-11-01

This paper presents the design, implementation and experimental validation of a novel robotic haptic exoskeleton device to measure the user's hand motion and assist hand motion while remaining portable and lightweight. The device consists of a five-finger mechanism actuated with miniature DC motors through antagonistically routed cables at each finger, which act as both active and passive force actuators. The SAFE Glove is a wireless and self-contained mechatronic system that mounts over the dorsum of a bare hand and provides haptic force feedback to each finger. The glove is adaptable to a wide variety of finger sizes without constraining the range of motion. This makes it possible to accurately and comfortably track the complex motion of the finger and thumb joints associated with common movements of hand functions, including grip and release patterns. The glove can be wirelessly linked to a computer for displaying and recording the hand status through 3D Graphical User Interface (GUI) in real-time. The experimental results demonstrate that the SAFE Glove is capable of reliably modeling hand kinematics, measuring finger motion and assisting hand grasping motion. Simulation and experimental results show the potential of the proposed system in rehabilitation therapy and virtual reality applications.

Validation of hand and foot anatomical feature measurements from smartphone images

NASA Astrophysics Data System (ADS)

Amini, Mohammad; Vasefi, Fartash; MacKinnon, Nicholas

2018-02-01

A smartphone mobile medical application, previously presented as a tool for individuals with hand arthritis to assess and monitor the progress of their disease, has been modified and expanded to include extraction of anatomical features from the hand (joint/finger width, and angulation) and foot (length, width, big toe angle, and arch height index) from smartphone camera images. Image processing algorithms and automated measurements were validated by performing tests on digital hand models, rigid plastic hand models, and real human hands and feet to determine accuracy and reproducibility compared to conventional measurement tools such as calipers, rulers, and goniometers. The mobile application was able to provide finger joint width measurements with accuracy better than 0.34 (+/-0.25) millimeters. Joint angulation measurement accuracy was better than 0.50 (+/-0.45) degrees. The automatically calculated foot length accuracy was 1.20 (+/-1.27) millimeters and the foot width accuracy was 1.93 (+/-1.92) millimeters. Hallux valgus angle (used in assessing bunions) accuracy was 1.30 (+/-1.29) degrees. Arch height index (AHI) measurements had an accuracy of 0.02 (+/-0.01). Combined with in-app documentation of symptoms, treatment, and lifestyle factors, the anatomical feature measurements can be used by both healthcare professionals and manufacturers. Applications include: diagnosing hand osteoarthritis; providing custom finger splint measurements; providing compression glove measurements for burn and lymphedema patients; determining foot dimensions for custom shoe sizing, insoles, orthotics, or foot splints; and assessing arch height index and bunion treatment effectiveness.

Design of Embedded System for Multivariate Classification of Finger and Thumb Movements Using EEG Signals for Control of Upper Limb Prosthesis.

PubMed

Rashid, Nasir; Iqbal, Javaid; Javed, Amna; Tiwana, Mohsin I; Khan, Umar Shahbaz

2018-01-01

Brain Computer Interface (BCI) determines the intent of the user from a variety of electrophysiological signals. These signals, Slow Cortical Potentials, are recorded from scalp, and cortical neuronal activity is recorded by implanted electrodes. This paper is focused on design of an embedded system that is used to control the finger movements of an upper limb prosthesis using Electroencephalogram (EEG) signals. This is a follow-up of our previous research which explored the best method to classify three movements of fingers (thumb movement, index finger movement, and first movement). Two-stage logistic regression classifier exhibited the highest classification accuracy while Power Spectral Density (PSD) was used as a feature of the filtered signal. The EEG signal data set was recorded using a 14-channel electrode headset (a noninvasive BCI system) from right-handed, neurologically intact volunteers. Mu (commonly known as alpha waves) and Beta Rhythms (8-30 Hz) containing most of the movement data were retained through filtering using "Arduino Uno" microcontroller followed by 2-stage logistic regression to obtain a mean classification accuracy of 70%.

Coregistered photoacoustic and ultrasound tomography of healthy and inflamed human interphalangeal joints

NASA Astrophysics Data System (ADS)

van Es, Peter; Vlieg, Redmar C.; Biswas, Samir K.; Hondebrink, Erwin; van Hespen, Johan C. G.; Moens, Hein B. J.; Steenbergen, Wiendelt; Manohar, Srirang

2015-07-01

Photoacoustic (PA) or optoacoustic (OA) imaging combines the high (blood) contrast to light with the high-resolution of ultrasound. The method can visualize vascularization deep inside tissue. Of late there is interest in PA imaging of synovial joints which are expected to be associated with increased vascularization in the event of rheumatoid arthritis (RA). We here describe our approach in investigating the application of the PA technique in arthritis. We are developing a CT-geometry version PA finger imager, intended for early clinical assessment of the method. The imager uses two curved array ultrasound detectors each with 64 elements with central frequencies 1.5 and 7.5 MHz respectively, stacked above each other. Both cover approximately 180 degrees of the circle. Illumination is provided with a multiple of optical fiber bundles coupled to a laser-OPO system. Ultrasound imaging is also possible with the system, since the curved arrays are each provided with 12 or 8 ultrasound pulsers. We have investigated systematically imaging of finger vasculature in healthy volunteers using an earlier laboratory prototype. In this paper we present finger imaging results of a patient diagnosed with rheumatoid arthritis.

Biomechanical and functional variation in rat sciatic nerve following cuff electrode implantation

PubMed Central

2014-01-01

Background Nerve cuff electrodes are commonly and successfully used for stimulating peripheral nerves. On the other hand, they occasionally induce functional and morphological changes following chronic implantation, for reasons not always clear. We hypothesize that restriction of nerve mobility due to cuff implantation may alter nerve conduction. Methods We quantified acute changes in nerve-muscle electrophysiology, using electromyography, and nerve kinematics in anesthetized Sprague Dawley rat sciatic nerves during controlled hindlimb joint movement. We compared electrophysiological and biomechanical response in uncuffed nerves and those secured within a cuff electrode using analysis of variance (ANOVA) and regression analysis. Results Tethering resulting from cuff implantation resulted in altered nerve strain and a complex biomechanical environment during joint movement. Coincident with biomechanical changes, electromyography revealed significantly increased variability in the response of conduction latency and amplitude in cuffed, but not free, nerves following joint movement. Conclusion Our findings emphasize the importance of the mechanical interface between peripheral nerves and their devices on neurophysiological performance. This work has implications for nerve device design, implantation, and prediction of long-term efficacy. PMID:24758405

Physicochemical and microscopic characterization of implant–abutment joints

PubMed Central

Lopes, Patricia A.; Carreiro, Adriana F. P.; Nascimento, Rubens M.; Vahey, Brendan R.; Henriques, Bruno; Souza, Júlio C. M.

2018-01-01

Objective: The purpose of this study was to investigate Morse taper implant–abutment joints by chemical, mechanical, and microscopic analysis. Materials and Methods: Surfaces of 10 Morse taper implants and the correlated abutments were inspected by field emission gun-scanning electron microscopy (FEG-SEM) before connection. The implant–abutment connections were tightened at 32 Ncm. For microgap evaluation by FEG-SEM, the systems were embedded in epoxy resin and cross-sectioned at a perpendicular plane of the implant–abutment joint. Furthermore, nanoindentation tests and chemical analysis were performed at the implant–abutment joints. Statistics: Results were statistically analyzed via one-way analysis of variance, with a significance level of P < 0.05. Results: Defects were noticed on different areas of the abutment surfaces. The minimum and maximum size of microgaps ranged from 0.5 μm up to 5.6 μm. Furthermore, defects were detected throughout the implant–abutment joint that can, ultimately, affect the microgap size after connection. Nanoindentation tests revealed a higher hardness (4.2 ± 0.4 GPa) for abutment composed of Ti6Al4V alloy when compared to implant composed of commercially pure Grade 4 titanium (3.2 ± 0.4 GPa). Conclusions: Surface defects produced during the machining of both implants and abutments can increase the size of microgaps and promote a misfit of implant–abutment joints. In addition, the mismatch in mechanical properties between abutment and implant can promote the wear of surfaces, affecting the size of microgaps and consequently the performance of the joints during mastication. PMID:29657532

Biomechanical loading on the upper extremity increases from single key tapping to directional tapping.

PubMed

Qin, Jin; Trudeau, Matthieu; Katz, Jeffrey N; Buchholz, Bryan; Dennerlein, Jack T

2011-08-01

Musculoskeletal disorders associated with computer use span the joints of the upper extremity. Computing typically involves tapping in multiple directions. Thus, we sought to describe the loading on the finger, wrist, elbow and shoulder joints in terms of kinematic and kinetic difference across single key switch tapping to directional tapping on multiple keys. An experiment with repeated measures design was conducted. Six subjects tapped with their right index finger on a stand-alone number keypad placed horizontally in three conditions: (1) on single key switch (the number key 5); (2) left and right on number key 4 and 6; (3) top and bottom on number key 8 and 2. A force-torque transducer underneath the keypad measured the fingertip force. An active-marker infrared motion analysis system measured the kinematics of the fingertip, hand, forearm, upper arm and torso. Joint moments for the metacarpophalangeal, wrist, elbow, and shoulder joints were estimated using inverse dynamics. Tapping in the top-bottom orientation introduced the largest biomechanical loading on the upper extremity especially for the proximal joint, followed by tapping in the left-right orientation, and the lowest loading was observed during single key switch tapping. Directional tapping on average increased the fingertip force, joint excursion, and peak-to-peak joint torque by 45%, 190% and 55%, respectively. Identifying the biomechanical loading patterns associated with these fundamental movements of keying improves the understanding of the risks of upper extremity musculoskeletal disorders for computer keyboard users. Copyright © 2010 Elsevier Ltd. All rights reserved.

Influence of the implant-abutment connection design and diameter on the screw joint stability.

PubMed

Shin, Hyon-Mo; Huh, Jung-Bo; Yun, Mi-Jeong; Jeon, Young-Chan; Chang, Brian Myung; Jeong, Chang-Mo

2014-04-01

This study was conducted to evaluate the influence of the implant-abutment connection design and diameter on the screw joint stability. Regular and wide-diameter implant systems with three different joint connection designs: an external butt joint, a one-stage internal cone, and a two-stage internal cone were divided into seven groups (n=5, in each group). The initial removal torque values of the abutment screw were measured with a digital torque gauge. The postload removal torque values were measured after 100,000 cycles of a 150 N and a 10 Hz cyclic load had been applied. Subsequently, the rates of the initial and postload removal torque losses were calculated to evaluate the effect of the joint connection design and diameter on the screw joint stability. Each group was compared using Kruskal-Wallis test and Mann-Whitney U test as post-hoc test (α=0.05). THE POSTLOAD REMOVAL TORQUE VALUE WAS HIGH IN THE FOLLOWING ORDER WITH REGARD TO MAGNITUDE: two-stage internal cone, one-stage internal cone, and external butt joint systems. In the regular-diameter group, the external butt joint and one-stage internal cone systems showed lower postload removal torque loss rates than the two-stage internal cone system. In the wide-diameter group, the external butt joint system showed a lower loss rate than the one-stage internal cone and two-stage internal cone systems. In the two-stage internal cone system, the wide-diameter group showed a significantly lower loss rate than the regular-diameter group (P<.05). The results of this study showed that the external butt joint was more advantageous than the internal cone in terms of the postload removal torque loss. For the difference in the implant diameter, a wide diameter was more advantageous in terms of the torque loss rate.

Influence of the implant-abutment connection design and diameter on the screw joint stability

PubMed Central

Shin, Hyon-Mo; Huh, Jung-Bo; Yun, Mi-Jeong; Jeon, Young-Chan; Chang, Brian Myung

2014-01-01

PURPOSE This study was conducted to evaluate the influence of the implant-abutment connection design and diameter on the screw joint stability. MATERIALS AND METHODS Regular and wide-diameter implant systems with three different joint connection designs: an external butt joint, a one-stage internal cone, and a two-stage internal cone were divided into seven groups (n=5, in each group). The initial removal torque values of the abutment screw were measured with a digital torque gauge. The postload removal torque values were measured after 100,000 cycles of a 150 N and a 10 Hz cyclic load had been applied. Subsequently, the rates of the initial and postload removal torque losses were calculated to evaluate the effect of the joint connection design and diameter on the screw joint stability. Each group was compared using Kruskal-Wallis test and Mann-Whitney U test as post-hoc test (α=0.05). RESULTS The postload removal torque value was high in the following order with regard to magnitude: two-stage internal cone, one-stage internal cone, and external butt joint systems. In the regular-diameter group, the external butt joint and one-stage internal cone systems showed lower postload removal torque loss rates than the two-stage internal cone system. In the wide-diameter group, the external butt joint system showed a lower loss rate than the one-stage internal cone and two-stage internal cone systems. In the two-stage internal cone system, the wide-diameter group showed a significantly lower loss rate than the regular-diameter group (P<.05). CONCLUSION The results of this study showed that the external butt joint was more advantageous than the internal cone in terms of the postload removal torque loss. For the difference in the implant diameter, a wide diameter was more advantageous in terms of the torque loss rate. PMID:24843398

Hip Implant Modified To Increase Probability Of Retention

NASA Technical Reports Server (NTRS)

Canabal, Francisco, III

1995-01-01

Modification in design of hip implant proposed to increase likelihood of retention of implant in femur after hip-repair surgery. Decreases likelihood of patient distress and expense associated with repetition of surgery after failed implant procedure. Intended to provide more favorable flow of cement used to bind implant in proximal extreme end of femur, reducing structural flaws causing early failure of implant/femur joint.

Toward development of mobile application for hand arthritis screening.

PubMed

Akhbardeh, Farhad; Vasefi, Fartash; Tavakolian, Kouhyar; Bradley, David; Fazel-Rezai, Reza

2015-01-01

Arthritis is one of the most common health problems affecting people throughout the world. The goal of the work presented in this paper is to provide individuals, who may be developing or have developed arthritis, with a mobile application to assess and monitor the progress of their disease using their smartphone. The image processing algorithm includes finger border detection algorithm to monitor joint thickness and angular deviation abnormalities, which are common symptoms of arthritis. In this work, we have analyzed and compared gradient, thresholding and Canny algorithms for border detection. The effect of image spatial resolution (down-sampling) is also investigated. The results calculated based on 36 joint measurements show that the mean errors for gradient, thresholding, and Canny methods are 0.20, 2.13, and 2.03 mm, respectively. In addition, the average error for different image resolutions is analyzed and the minimum required resolution is determined for each method. The results confirm that recent smartphone imaging capabilities can provide enough accuracy for hand border detection and finger joint analysis based on gradient method.

Analyzer-based imaging technique in tomography of cartilage and metal implants: a study at the ESRF

PubMed Central

COAN, Paola; MOLLENHAUER, Juergen; WAGNER, Andreas; Muehleman, Carol; BRAVIN, Alberto

2009-01-01

Monitoring the progression of osteoarthritis (OA) and the effects of therapy during clinical trials is still a challenge for present clinical imaging techniques since they present intrinsic limitations and can be sensitive only in case of advanced OA stages. In very severe cases, partial or complete joint replacement surgery is the only solution for reducing pain and restoring the joint functions. Poor imaging quality in practically all medical imaging technologies with respect to joint surfaces and to metal implant imaging calls for the development of new techniques that are sensitive to stages preceding the point of irreversible damage of the cartilage tissue. In this scenario, X-ray phase contrast modalities could play an important role since they can provide improved contrast compared to conventional absorption radiography, with a similar or even reduced tissue radiation dose. In this study, the Analyzer-based imaging (ABI), a technique sensitive to the X-ray refraction and permitting a high scatter rejection, has been successfully applied in-vitro on excised human synovial joints and sheep implants. Pathological and healthy joints as well as metal implants have been imaged in projection and computed tomography ABI mode at high resolution and clinically compatible doses (< 10 mGy). Volume rendering and segmentation permitted visualization of the cartilage from volumetric CT-scans. Results demonstrate that ABI can provide an unequivocal non-invasive diagnosis of the state of disease of the joint and be considered a new tool in orthopaedic research. PMID:18584983

Design and Characterization of a Soft Robotic Therapeutic Glove for Rheumatoid Arthritis.

PubMed

Chua, Matthew Chin Heng; Lim, Jeong Hoon; Yeow, Raye Chen Hua

2017-07-27

The modeling and experimentation of a pneumatic actuation system for the development of a soft robotic therapeutic glove is proposed in this article for the prevention of finger deformities in rheumatoid arthritis (RA) patients. The Rehabilitative Arthritis Glove (RA-Glove) is a soft robotic glove fitted with two internal inflatable actuators for lateral compression and massage of the fingers and their joints. Two mechanical models to predict the indentation and bending characteristics of the inflatable actuators based on their geometrical parameters will be presented and validated with experimental results. Experimental validation shows that the model was within a standard deviation of the experimental mean for input pressure range of 0 to 2 bars. Evaluation of the RA-Glove was also performed on six healthy human subjects. The stress distribution along the fingers of the subjects using the RA-Glove was also shown to be even and specific to the finger sizes. This article demonstrates the modeling of soft pneumatic actuators and highlights the potential of the RA-Glove as a therapeutic device for the prevention of arthritic deformities of the fingers.

Bioactive Coatings for Orthopaedic Implants—Recent Trends in Development of Implant Coatings

PubMed Central

Zhang, Bill G. X.; Myers, Damian E.; Wallace, Gordon G.; Brandt, Milan; Choong, Peter F. M.

2014-01-01

Joint replacement is a major orthopaedic procedure used to treat joint osteoarthritis. Aseptic loosening and infection are the two most significant causes of prosthetic implant failure. The ideal implant should be able to promote osteointegration, deter bacterial adhesion and minimize prosthetic infection. Recent developments in material science and cell biology have seen the development of new orthopaedic implant coatings to address these issues. Coatings consisting of bioceramics, extracellular matrix proteins, biological peptides or growth factors impart bioactivity and biocompatibility to the metallic surface of conventional orthopaedic prosthesis that promote bone ingrowth and differentiation of stem cells into osteoblasts leading to enhanced osteointegration of the implant. Furthermore, coatings such as silver, nitric oxide, antibiotics, antiseptics and antimicrobial peptides with anti-microbial properties have also been developed, which show promise in reducing bacterial adhesion and prosthetic infections. This review summarizes some of the recent developments in coatings for orthopaedic implants. PMID:25000263

Development of reaching during mid-childhood from a Developmental Systems perspective.

PubMed

Golenia, Laura; Schoemaker, Marina M; Otten, Egbert; Mouton, Leonora J; Bongers, Raoul M

2018-01-01

Inspired by the Developmental Systems perspective, we studied the development of reaching during mid-childhood (5-10 years of age) not just at the performance level (i.e., endpoint movements), as commonly done in earlier studies, but also at the joint angle level. Because the endpoint position (i.e., the tip of the index finger) at the reaching target can be achieved with multiple joint angle combinations, we partitioned variability in joint angles over trials into variability that does not (goal-equivalent variability, GEV) and that does (non-goal-equivalent variability, NGEV) influence the endpoint position, using the Uncontrolled Manifold method. Quantifying this structure in joint angle variability allowed us to examine whether and how spatial variability of the endpoint at the reaching target is related to variability in joint angles and how this changes over development. 6-, 8- and 10-year-old children and young adults performed reaching movements to a target with the index finger. Polynomial trend analysis revealed a linear and a quadratic decreasing trend for the variable error. Linear decreasing and cubic trends were found for joint angle standard deviations at movement end. GEV and NGEV decreased gradually with age, but interestingly, the decrease of GEV was steeper than the decrease of NGEV, showing that the different parts of the joint angle variability changed differently over age. We interpreted these changes in the structure of variability as indicating changes over age in exploration for synergies (a family of task solutions), a concept that links the performance level with the joint angle level. Our results suggest changes in the search for synergies during mid-childhood development.

Fatigue limits of titanium-bar joints made with the laser and the electric resistance welding techniques: microstructural characterization and hardness properties.

PubMed

Degidi, Marco; Nardi, Diego; Morri, Alessandro; Sighinolfi, Gianluca; Tebbel, Florian; Marchetti, Claudio

2017-09-01

Fatigue behavior of the titanium bars is of utmost importance for the safe and reliable operation of dental implants and prosthetic constructions based on these implants. To date, however, only few data are available on the fatigue strength of dental prostheses made with electric resistance welding and laser welding techniques. This in-vitro study highlighted that although the joints made with the laser welding approach are credited of a superior tensile strength, joints made with electric resistance welding exhibited double the minimum fatigue strength with respect to the joints made with laser welding (120 vs 60 N).

3D reconstruction of bony elements of the knee joint and finite element analysis of total knee prosthesis obtained from the reconstructed model.

PubMed

Djoudi, Farid

2013-01-01

Two separate themes are presented in this paper. The first theme is to present a graphical modeling approach of human anatomical structures namely, the femur and the tibia. The second theme involves making a finite element analysis of stresses, displacements and deformations in prosthetic implants (the femoral implant and the polyethylene insert). The graphical modeling approach comes in two parts. The first is the segmentation of MRI scanned images, retrieved in DICOM format for edge detection. In the second part, 3D-CAD models are generated from the results of the segmentation stage. The finite element analysis is done by first extracting the prosthetic implants from the reconstructed 3D-CAD model, then do a finite element analysis of these implants under objectively determined conditions such as; forces, allowed displacements, the materials composing implant, and the coefficient of friction. The objective of this work is to implement an interface for exchanging data between 2D MRI images obtained from a medical diagnosis of a patient and the 3D-CAD model used in various applications, such as; the extraction of the implants, stress analysis at the knee joint and can serve as an aid to surgery, also predict the behavior of the prosthetic implants vis-a-vis the forces acting on the knee joints.

MR Imaging of Knee Arthroplasty Implants

PubMed Central

Fritz, Jan; Lurie, Brett

2015-01-01

Primary total knee arthroplasty is a highly effective treatment that relieves pain and improves joint function in a large percentage of patients. Despite an initially satisfactory surgical outcome, pain, dysfunction, and implant failure can occur over time. Identifying the etiology of complications is vital for appropriate management and proper timing of revision. Due to the increasing number of knee arthroplasties performed and decreasing patient age at implantation, there is a demand for accurate diagnosis to determine appropriate treatment of symptomatic joints following knee arthroplasty, and for monitoring of patients at risk. Magnetic resonance (MR) imaging allows for comprehensive imaging evaluation of the tissues surrounding knee arthroplasty implants with metallic components, including the polyethylene components. Optimized conventional and advanced pulse sequences can result in substantial metallic artifact reduction and afford improved visualization of bone, implant-tissue interfaces, and periprosthetic soft tissue for the diagnosis of arthroplasty-related complications. In this review article, we discuss strategies for MR imaging around knee arthroplasty implants and illustrate the imaging appearances of common modes of failure, including aseptic loosening, polyethylene wear–induced synovitis and osteolysis, periprosthetic joint infections, fracture, patellar clunk syndrome, recurrent hemarthrosis, arthrofibrosis, component malalignment, extensor mechanism injury, and instability. A systematic approach is provided for evaluation of MR imaging of knee implants. MR imaging with optimized conventional pulse sequences and advanced metal artifact reduction techniques can contribute important information for diagnosis, prognosis, risk stratification, and surgical planning. ©RSNA, 2015 PMID:26295591

Targeted Disruption of Mouse Yin Yang 1 Transcription Factor Results in Peri-Implantation Lethality

PubMed Central

Donohoe, Mary E.; Zhang, Xiaolin; McGinnis, Lynda; Biggers, John; Li, En; Shi, Yang

1999-01-01

Yin Yang 1 (YY1) is a zinc finger-containing transcription factor and a target of viral oncoproteins. To determine the biological role of YY1 in mammalian development, we generated mice deficient for YY1 by gene targeting. Homozygosity for the mutated YY1 allele results in embryonic lethality in the mouse. YY1 mutants undergo implantation and induce uterine decidualization but rapidly degenerate around the time of implantation. A subset of YY1 heterozygote embryos are developmentally retarded and exhibit neurulation defects, suggesting that YY1 may have additional roles during later stages of mouse embryogenesis. Our studies demonstrate an essential function for YY1 in the development of the mouse embryo. PMID:10490658

A new universal, standardized implant database for product identification: a unique tool for arthroplasty registries.

PubMed

Blömer, Wilhelm; Steinbrück, Arnd; Schröder, Christian; Grothaus, Franz-Josef; Melsheimer, Oliver; Mannel, Henrich; Forkel, Gerhard; Eilers, Thomas; Liebs, Thoralf R; Hassenpflug, Joachim; Jansson, Volkmar

2015-07-01

Every joint registry aims to improve patient care by identifying implants that have an inferior performance. For this reason, each registry records the implant name that has been used in the individual patient. In most registries, a paper-based approach has been utilized for this purpose. However, in addition to being time-consuming, this approach does not account for the fact that failure patterns are not necessarily implant specific but can be associated with design features that are used in a number of implants. Therefore, we aimed to develop and evaluate an implant product library that allows both time saving barcode scanning on site in the hospital for the registration of the implant components and a detailed description of implant specifications. A task force consisting of representatives of the German Arthroplasty Registry, industry, and computer specialists agreed on a solution that allows barcode scanning of implant components and that also uses a detailed standardized classification describing arthroplasty components. The manufacturers classified all their components that are sold in Germany according to this classification. The implant database was analyzed regarding the completeness of components by algorithms and real-time data. The implant library could be set up successfully. At this point, the implant database includes more than 38,000 items, of which all were classified by the manufacturers according to the predefined scheme. Using patient data from the German Arthroplasty Registry, several errors in the database were detected, all of which were corrected by the respective implant manufacturers. The implant library that was developed for the German Arthroplasty Registry allows not only on-site barcode scanning for the registration of the implant components but also its classification tree allows a sophisticated analysis regarding implant characteristics, regardless of brand or manufacturer. The database is maintained by the implant manufacturers, thereby allowing registries to focus their resources on other areas of research. The database might represent a possible global model, which might encourage harmonization between joint replacement registries enabling comparisons between joint replacement registries.

In Vivo Assessment of Phage and Linezolid Based Implant Coatings for Treatment of Methicillin Resistant S. aureus (MRSA) Mediated Orthopaedic Device Related Infections

PubMed Central

Kaur, Sandeep; Harjai, Kusum; Chhibber, Sanjay

2016-01-01

Staphylococcus comprises up to two-thirds of all pathogens in orthopaedic implant infections with two species respectively Staphylococcus aureus and Staphylococcus epidermidis, being the predominate etiological agents isolated. Further, with the emergence of methicillin-resistant S. aureus (MRSA), treatment of S. aureus implant infections has become more difficult, thus representing a devastating complication. Use of local delivery system consisting of S.aureus specific phage along with linezolid (incorporated in biopolymer) allowing gradual release of the two agents at the implant site represents a new, still unexplored treatment option (against orthopaedic implant infections) that has been studied in an animal model of prosthetic joint infection. Naked wire, hydroxypropyl methylcellulose (HPMC) coated wire and phage and /or linezolid coated K-wire were surgically implanted into the intra-medullary canal of mouse femur bone of respective groups followed by inoculation of S.aureus ATCC 43300(MRSA). Mice implanted with K-wire coated with both the agents i.e phage as well as linezolid (dual coated wires) showed maximum reduction in bacterial adherence, associated inflammation of the joint as well as faster resumption of locomotion and motor function of the limb. Also, all the coating treatments showed no emergence of resistant mutants. Use of dual coated implants incorporating lytic phage (capable of self-multiplication) as well as linezolid presents an attractive and aggressive early approach in preventing as well as treating implant associated infections caused by methicillin resistant S. aureus strains as assessed in a murine model of experimental joint infection. PMID:27333300

[Design and application of implantable medical device information management system].

PubMed

Cao, Shaoping; Yin, Chunguang; Zhao, Zhenying

2013-03-01

Through the establishment of implantable medical device information management system, with the aid of the regional joint sharing of resources, we further enhance the implantable medical device traceability management level, strengthen quality management, control of medical risk.

The 1990-1991 project summaries

NASA Technical Reports Server (NTRS)

1991-01-01

Georgia Tech's School of Textile & Fiber Engineering and School of Mechanical Engineering participated in four cooperative design efforts this year. One group designed a thermal shield for a lunar telescope. The second group designed a selenotextile habitat shielding structure. The third group designed a pneumatically assisted elbow joint for the NASA zero-prebreathe suit (ZPS). The final group designed an electromechanical system to power an astronaut's finger joints. Summaries of these projects are presented.

The 1990-1991 project summaries

NASA Astrophysics Data System (ADS)

Georgia Tech's School of Textile & Fiber Engineering and School of Mechanical Engineering participated in four cooperative design efforts this year. One group designed a thermal shield for a lunar telescope. The second group designed a selenotextile habitat shielding structure. The third group designed a pneumatically assisted elbow joint for the NASA zero-prebreathe suit (ZPS). The final group designed an electromechanical system to power an astronaut's finger joints. Summaries of these projects are presented.

Unfavourable short-term outcomes of a poly-L/D-lactide scaffold for thumb trapeziometacarpal arthroplasty.

PubMed

Mattila, S; Waris, E

2016-03-01

The bioabsorbable poly-L-D-lactide joint scaffold arthroplasty is a recent attempt in the reconstruction of small joints in rheumatoid patients. In this study, we analysed the 1-year clinical, functional and radiologic results of partial trapeziectomy with the poly-L-D-lactide (96/4) joint scaffold in 23 patients with isolated trapeziometacarpal osteoarthritis. The results showed that the procedure provided pain relief and improvement in overall function according to the Quick Disabilities of the Arm, Shoulder and Hand score in most patients. However, radiographs demonstrated a high frequency of osteolysis around the implant. Seven patients developed clinically manifested foreign-body reactions 6 months to 1 year after surgery. The reason for the unexpected tissue reactions may relate to excessive mechanical cyclic loading of the implant. The outcomes of this implant in our patients have not been sufficiently beneficial and we have discontinued use of this implant in isolated trapeziometacarpal osteoarthritis. © The Author(s) 2015.

Further delineation of Nevo syndrome.

PubMed Central

al-Gazali, L I; Bakalinova, D; Varady, E; Scorer, J; Nork, M

1997-01-01

Nevo syndrome is an autosomal recessive syndrome characterised by prenatal overgrowth, joint laxity, kyphosis, wrist drop, spindle shaped fingers, and volar oedema. Four children from two families have been reported previously. We report two further children from two unrelated Arab families from two different tribes. Both presented at birth with hypotonia, joint laxity, kyphosis, wrist drop, spindle shaped fingers, and volar oedema. Both have delayed motor development at the ages of 2 years 10 months and 3 months respectively. Cognitive development is normal in one, and the other case appears to be developing normally at 3 months of age. One has, in addition, a wide spinal canal on MRI of the spine indicating some degree of dural ectasia. This report brings the total number of children reported with this syndrome to six from four families; three of these families are Arab. This indicates that the gene for this syndrome is probably commoner in Arabs than in other populations. Images PMID:9152832

Optical tomographic detection of rheumatoid arthritis with computer-aided classification schemes

NASA Astrophysics Data System (ADS)

Klose, Christian D.; Klose, Alexander D.; Netz, Uwe; Beuthan, Jürgen; Hielscher, Andreas H.

2009-02-01

A recent research study has shown that combining multiple parameters, drawn from optical tomographic images, leads to better classification results to identifying human finger joints that are affected or not affected by rheumatic arthritis RA. Building up on the research findings of the previous study, this article presents an advanced computer-aided classification approach for interpreting optical image data to detect RA in finger joints. Additional data are used including, for example, maximum and minimum values of the absorption coefficient as well as their ratios and image variances. Classification performances obtained by the proposed method were evaluated in terms of sensitivity, specificity, Youden index and area under the curve AUC. Results were compared to different benchmarks ("gold standard"): magnet resonance, ultrasound and clinical evaluation. Maximum accuracies (AUC=0.88) were reached when combining minimum/maximum-ratios and image variances and using ultrasound as gold standard.

Enhancement of healing in osteochondral defects by collagen sponge implants.

PubMed

Speer, D P; Chvapil, M; Volz, R G; Holmes, M D

1979-10-01

Implants of porous, highly cross-linked collagen sponge (CS) were tested for their capacity to enhance the healing of osteochondral defects in rabbits. Comparison was made to the healing of similar defects with polyvinyl alcohol sponge (PVAS) implants and with no implants (CONT). Evaluation was carried out up to 44 weeks following implantation and included observation of host cellular response, biodegradability of implant, gross appearance of restored joint surface, collagenous architecture of repair tissue, and properties of the junctions of implants and host articular cartilage, subchondral bone, and medullary bone. Collagen sponge proved most effective in promoting healing of osteochondral defects with fibrous and fibrocartilaginous tissue over restored subchondral bone. Collagen sponge showed many desirable properties as a potential material for biologic resurfacing of damaged joints. These properties included porosity, biodegradability, biocompatability, ability to mechanically protect cells and matrix while directing cell ingrowth, and an available chemical technology for modifying its biomechanical and biological properties. Comparative analysis of results of healing of CS, PVAS, and CONT osteochondral defects suggest rational design criteria for implant materials to improve their effectiveness in restoration of articular surfaces.

Design and clinical outcome of a novel 3D-printed prosthetic joint replacement for the human temporomandibular joint.

PubMed

Ackland, David; Robinson, Dale; Lee, Peter Vee Sin; Dimitroulis, George

2018-05-11

Stock prosthetic temporomandibular joint replacements come in limited sizes, and do not always encompass the joint anatomy that presents clinically. The aims of this study were twofold. Firstly, to design a personalized prosthetic total joint replacement for the treatment of a patient's end-stage temporomandibular joint osteoarthritis, to implant the prosthesis into the patient, and assess clinical outcome 12-months post-operatively; and secondly, to evaluate the influence of changes in prosthetic condyle geometry on implant load response during mastication. A 48-year-old female patient with Grade-5 osteoarthritis to the left temporomandibular joint was recruited, and a prosthesis developed to match the native temporomandibular joint anatomy. The prosthesis was 3D printed, sterilized and implanted into the patient, and pain and function measured 12-months post-operatively. The prosthesis load response during a chewing-bite and maximum-force bite was evaluated using a personalized multi-body musculoskeletal model. Simulations were performed after perturbing condyle thickness, neck length and head sphericity. Increases in prosthetic condyle neck length malaligned the mandible and perturbed temporomandibular joint force. Changes in condylar component thickness greatly influenced fixation screw stress response, while a more eccentric condylar head increased prosthetic joint-contact loading. Post-operatively, the prosthetic temporomandibular joint surgery reduced patient pain from 7/10 to 1/10 on a visual analog scale, and increased intercisal opening distance from 22 mm to 38 mm. This study demonstrates effectiveness of a personalized prosthesis that may ultimately be adapted to treat a wide-range of end-stage temporomandibular joint conditions, and highlights sensitivity of prosthesis load response to changes in condylar geometry. Copyright © 2018 Elsevier Ltd. All rights reserved.

Investigation of an alleged mechanism of finger injury in an automobile crash.

PubMed

Stacey, Stephen; Kent, Richard

2006-07-01

This investigation centers on the case of an adult male whose finger was allegedly amputated by the steering wheel of his car during a crash. The subject claimed to have been driving with his left index finger inserted through a hole in the spoke of his steering wheel and was subsequently involved in an offset frontal collision with a tree. The finger was found to be cleanly severed at the mid-shaft of the proximal phalanx after the crash. This injury was alleged to have been caused by inertial loading from the rotation of the steering wheel during the crash. To determine whether this injury mechanism was plausible, three laboratory tests representing distinct loading scenarios were carried out with postmortem human surrogates loaded dynamically by the subject's steering wheel. It was found that the inertial loads generated in this loading scenario are insufficient to amputate the finger. Additionally, artificially constraining the finger to force an amputation to occur revealed that a separation at the proximal interphalangeal joint occurs rather than a bony fracture of the proximal phalanx. Based on these biomechanical tests, it can be concluded that the subject's injury did not occur during the automobile crash in question. Furthermore, it can be shown that the injury was self-inflicted to fraudulently claim on an insurance policy.

Finding glenoid surface on scapula in 3D medical images for shoulder joint implant operation planning: 3D OCR

NASA Astrophysics Data System (ADS)

Mohammad Sadeghi, Majid; Kececi, Emin Faruk; Bilsel, Kerem; Aralasmak, Ayse

2017-03-01

Medical imaging has great importance in earlier detection, better treatment and follow-up of diseases. 3D Medical image analysis with CT Scan and MRI images has also been used to aid surgeries by enabling patient specific implant fabrication, where having a precise three dimensional model of associated body parts is essential. In this paper, a 3D image processing methodology for finding the plane on which the glenoid surface has a maximum surface area is proposed. Finding this surface is the first step in designing patient specific shoulder joint implant.

Multidisciplinary approach for in-deep assessment of joint prosthesis failure.

PubMed

Tessarolo, F; Caola, I; Piccoli, F; Dorigotti, P; Demattè, E; Molinari, M; Malavolta, M; Barbareschi, M; Caciagli, P; Nollo, G

2009-01-01

In spite of advancement in biomaterials and biomechanics, in development of new osteo-integrative materials and coatings, and in macro- micro- component design, a non negligible fraction of the implanted prosthesis fails before the expected lifetime. A prospective observational clinical study has been conducted to define and apply a set of experimental techniques to in-deep assess the failure of joint prosthesis. Microbiological, histological and micro-structural techniques were implemented to specifically address phenomena occurring at the tissue-implant interface. Results obtained from 27 cases of prosthetic joint failure are discussed in terms of sensitivity and specificity. A procedural flow-chart is finally proposed for the assessment of joint prosthesis failure.

Automatic joint alignment measurements in pre- and post-operative long leg standing radiographs.

PubMed

Goossen, A; Weber, G M; Dries, S P M

2012-01-01

For diagnosis or treatment assessment of knee joint osteoarthritis it is required to measure bone morphometry from radiographic images. We propose a method for automatic measurement of joint alignment from pre-operative as well as post-operative radiographs. In a two step approach we first detect and segment any implants or other artificial objects within the image. We exploit physical characteristics and avoid prior shape information to cope with the vast amount of implant types. Subsequently, we exploit the implant delineations to adapt the initialization and adaptation phase of a dedicated bone segmentation scheme using deformable template models. Implant and bone contours are fused to derive the final joint segmentation and thus the alignment measurements. We evaluated our method on clinical long leg radiographs and compared both the initialization rate, corresponding to the number of images successfully processed by the proposed algorithm, and the accuracy of the alignment measurement. Ground truth has been generated by an experienced orthopedic surgeon. For comparison a second reader reevaluated the measurements. Experiments on two sets of 70 and 120 digital radiographs show that 92% of the joints could be processed automatically and the derived measurements of the automatic method are comparable to a human reader for pre-operative as well as post-operative images with a typical error of 0.7° and correlations of r = 0.82 to r = 0.99 with the ground truth. The proposed method allows deriving objective measures of joint alignment from clinical radiographs. Its accuracy and precision are on par with a human reader for all evaluated measurements.

Development of anthropomorphic robotic hand driven by Pneumatic Artificial Muscles for robotic applications

NASA Astrophysics Data System (ADS)

Farag, Mohannad; Zainul Azlan, Norsinnira; Hayyan Alsibai, Mohammed

2018-04-01

This paper presents the design and fabrication of a three-fingered anthropomorphic robotic hand. The fingers are driven by tendons and actuated by human muscle-like actuators known as Pneumatic Artificial Muscle (PAM). The proposed design allows the actuators to be mounted outside the hand where each finger can be driven by one PAM actuator and six indirectly interlinked tendons. With this design, the three-fingered hand has a compact size and a lightweight with a mass of 150.25 grams imitating the human being hand in terms of size and weight. The hand also successfully grasped objects with different shapes and weights up to 500 g. Even though the number of PAM actuators equals the number of Degrees of Freedom (DOF), the design guarantees driving of three joints by only one actuator reducing the number of required actuators from 3 to 1. Therefore, this hand is suitable for researches of robotic applications in terms of design, cost and ability to be equipped with several types of sensors.

Successful conservative treatment outcomes and clinical characteristics of congenital hypoplasia of the extensor tendon central slip.

PubMed

Hidaka, N; Uemura, T; Nakamura, H

2017-03-01

Congenital hypoplasia of the extensor tendon central slip is a rare entity. This article describes the clinical characteristics in a series of 22 fingers in 16 patients (mean age: 10 months), and the outcomes of conservative treatment. Nine of 22 fingers were classified as slender or hypoplastic. Treatment with bracing was successful in 21 digits, resulting in full active extension of the proximal interphalangeal joint at a mean of 8.5 months after treatment. Bracing was unsuccessful in one digit, in which operative treatment resulted in a successful outcome. Some residual deformity was observed in ten fingers after a mean follow-up period of 2 years and 1 month. Congenital hypoplasia of the central slip can be treated successfully by the conservative hand bracing when worn with full compliance. Treatment time is extended by the infrequent application of the hand brace or in the case of hypoplastic slender fingers. IV.

21 CFR 888.3800 - Wrist joint metal/polymer semi-constrained cemented prosthesis.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Wrist joint metal/polymer semi-constrained... Wrist joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. A wrist joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a wrist joint...

21 CFR 888.3800 - Wrist joint metal/polymer semi-constrained cemented prosthesis.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Wrist joint metal/polymer semi-constrained... Wrist joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. A wrist joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a wrist joint...

21 CFR 888.3800 - Wrist joint metal/polymer semi-constrained cemented prosthesis.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Wrist joint metal/polymer semi-constrained... Wrist joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. A wrist joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a wrist joint...

21 CFR 888.3800 - Wrist joint metal/polymer semi-constrained cemented prosthesis.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Wrist joint metal/polymer semi-constrained... Wrist joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. A wrist joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a wrist joint...

21 CFR 888.3800 - Wrist joint metal/polymer semi-constrained cemented prosthesis.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Wrist joint metal/polymer semi-constrained... Wrist joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. A wrist joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a wrist joint...

Motor impairments related to brain injury timing in early hemiparesis. Part II: abnormal upper extremity joint torque synergies.

PubMed

Sukal-Moulton, Theresa; Krosschell, Kristin J; Gaebler-Spira, Deborah J; Dewald, Julius P A

2014-01-01

Extensive neuromotor development occurs early in human life, and the timing of brain injury may affect the resulting motor impairment. In Part I of this series, it was demonstrated that the distribution of weakness in the upper extremity depended on the timing of brain injury in individuals with childhood-onset hemiparesis. The goal of this study was to characterize how timing of brain injury affects joint torque synergies, or losses of independent joint control. Twenty-four individuals with hemiparesis were divided into 3 groups based on the timing of their injury: before birth (PRE-natal, n = 8), around the time of birth (PERI-natal, n = 8), and after 6 months of age (POST-natal, n = 8). Individuals with hemiparesis and 8 typically developing peers participated in maximal isometric shoulder, elbow, wrist, and finger torque generation tasks while their efforts were recorded by a multiple degree-of-freedom load cell. Motor output in 4 joints of the upper extremity was concurrently measured during 8 primary torque generation tasks to quantify joint torque synergies. There were a number of significant coupling patterns identified in individuals with hemiparesis that differed from the typically developing group. POST-natal differences were most noted in the coupling of shoulder abductors with elbow, wrist, and finger flexors, while the PRE-natal group demonstrated significant distal joint coupling with elbow flexion. The torque synergies measured provide indirect evidence for the use of bulbospinal pathways in the POST-natal group, while those with earlier injury may use relatively preserved ipsilateral corticospinal motor pathways.

Quantitative three-dimensional photoacoustic tomography of the finger joints: an in vivo study

NASA Astrophysics Data System (ADS)

Sun, Yao; Sobel, Eric; Jiang, Huabei

2009-11-01

We present for the first time in vivo full three-dimensional (3-D) photoacoustic tomography (PAT) of the distal interphalangeal joint in a human subject. Both absorbed energy density and absorption coefficient images of the joint are quantitatively obtained using our finite-element-based photoacoustic image reconstruction algorithm coupled with the photon diffusion equation. The results show that major anatomical features in the joint along with the side arteries can be imaged with a 1-MHz transducer in a spherical scanning geometry. In addition, the cartilages associated with the joint can be quantitatively differentiated from the phalanx. This in vivo study suggests that the 3-D PAT method described has the potential to be used for early diagnosis of joint diseases such as osteoarthritis and rheumatoid arthritis.

Do modern total knee replacements offer better value for money? A health economic analysis.

PubMed

Hamilton, David F; Clement, Nicholas D; Burnett, Richard; Patton, James T; Moran, Mathew; Howie, Colin R; Simpson, A H R W; Gaston, Paul

2013-11-01

Cost effectiveness is an increasingly important factor in today's healthcare environment, and selection of arthroplasty implant is not exempt from such concerns. Quality adjusted life years (QALYs) are the typical tool for this type of evaluation. Using this methodology, joint arthroplasty has been shown to be cost effective; however, studies directly comparing differing prostheses are lacking. Data was gathered in a single-centre prospective double-blind randomised controlled trial comparing the outcome of modern and traditional knee implants, using the Short Form 6 dimensional (SF-6D) score and quality adjusted life year (QALY) methodology. There was significant improvement in the SF-6D score for both groups at one year (p < 0.0001). The calculated overall life expectancy for the study cohort was 15.1 years, resulting in an overall QALY gain of 2.144 (95% CI 1.752-2.507). The modern implant group demonstrated a small improvement in SF-6D score compared to the traditional design at one year (0.141 versus 0.143, p = 0.94). This difference resulted in the modern implant costing £298 less per QALY at one year. This study demonstrates that modern implant technology does not influence the cost-effectiveness of TKA using the SF-6D and QALY methodology. This type of analysis however assesses health status, and is not sensitive to joint specific function. Evolutionary design changes in implant technology are thus unlikely to influence QALY analysis following joint replacement, which has important implications for implant procurement.

Reorganization of finger coordination patterns through motor exploration in individuals after stroke.

PubMed

Ranganathan, Rajiv

2017-09-11

Impairment of hand and finger function after stroke is common and affects the ability to perform activities of daily living. Even though many of these coordination deficits such as finger individuation have been well characterized, it is critical to understand how stroke survivors learn to explore and reorganize their finger coordination patterns for optimizing rehabilitation. In this study, I examine the use of a body-machine interface to assess how participants explore their movement repertoire, and how this changes with continued practice. Ten participants with chronic stroke wore a data glove and the finger joint angles were mapped on to the position of a cursor on a screen. The task of the participants was to move the cursor back and forth between two specified targets on a screen. Critically, the map between the finger movements and cursor motion was altered so that participants sometimes had to generate coordination patterns that required finger individuation. There were two phases to the experiment - an initial assessment phase on day 1, followed by a learning phase (days 2-5) where participants trained to reorganize their coordination patterns. Participants showed difficulty in performing tasks which had maps that required finger individuation, and the degree to which they explored their movement repertoire was directly related to clinical tests of hand function. However, over four sessions of practice, participants were able to learn to reorganize their finger movement coordination pattern and improve their performance. Moreover, training also resulted in improvements in movement repertoire outside of the context of the specific task during free exploration. Stroke survivors show deficits in movement repertoire in their paretic hand, but facilitating movement exploration during training can increase the movement repertoire. This suggests that exploration may be an important element of rehabilitation to regain optimal function.

Design of Embedded System for Multivariate Classification of Finger and Thumb Movements Using EEG Signals for Control of Upper Limb Prosthesis

PubMed Central

Javed, Amna; Tiwana, Mohsin I.; Khan, Umar Shahbaz

2018-01-01

Brain Computer Interface (BCI) determines the intent of the user from a variety of electrophysiological signals. These signals, Slow Cortical Potentials, are recorded from scalp, and cortical neuronal activity is recorded by implanted electrodes. This paper is focused on design of an embedded system that is used to control the finger movements of an upper limb prosthesis using Electroencephalogram (EEG) signals. This is a follow-up of our previous research which explored the best method to classify three movements of fingers (thumb movement, index finger movement, and first movement). Two-stage logistic regression classifier exhibited the highest classification accuracy while Power Spectral Density (PSD) was used as a feature of the filtered signal. The EEG signal data set was recorded using a 14-channel electrode headset (a noninvasive BCI system) from right-handed, neurologically intact volunteers. Mu (commonly known as alpha waves) and Beta Rhythms (8–30 Hz) containing most of the movement data were retained through filtering using “Arduino Uno” microcontroller followed by 2-stage logistic regression to obtain a mean classification accuracy of 70%. PMID:29888252

Physiological joint line total knee arthroplasty designs are especially sensitive to rotational placement - A finite element analysis.

PubMed

Moewis, Philippe; Checa, Sara; Kutzner, Ines; Hommel, Hagen; Duda, Georg N

2018-01-01

Mechanical and kinematical aligning techniques are the usual positioning methods during total knee arthroplasty. However, alteration of the physiological joint line and unbalanced medio-lateral load distribution are considered disadvantages in the mechanical and kinematical techniques, respectively. The aim of this study was to analyse the influence of the joint line on the strain and stress distributions in an implanted knee and their sensitivity to rotational mal-alignment. Finite element calculations were conducted to analyse the stresses in the PE-Inlay and the mechanical strains at the bone side of the tibia component-tibia bone interface during normal positioning of the components and internal and external mal-rotation of the tibial component. Two designs were included, a horizontal and a physiological implant. The loading conditions are based on internal knee joint loads during walking. A medialization of the stresses on the PE-Inlay was observed in the physiological implant in a normal position, accompanied by higher stresses in the mal-rotated positions. Within the tibia component-tibia bone interface, similar strain distributions were observed in both implant geometries in the normal position. However, a medialization of the strains was observed in the physiological implant in both mal-rotated conditions with greater bone volume affected by higher strains. Although evident changes due to mal-rotation were observed, the stresses do not suggest a local plastic deformation of the PE-Inlay. The strains values within most of the tibia component-tibia bone interface were in the physiological strain zone and no significant bone changes would be expected. The physiological cut on the articular aspect showed no detrimental effect compared to the horizontal implant.

Analysis of Hand and Wrist Postural Synergies in Tolerance Grasping of Various Objects

PubMed Central

Liu, Yuan; Jiang, Li; Yang, Dapeng; Liu, Hong

2016-01-01

Human can successfully grasp various objects in different acceptable relative positions between human hand and objects. This grasp functionality can be described as the grasp tolerance of human hand, which is a significant functionality of human grasp. To understand the motor control of human hand completely, an analysis of hand and wrist postural synergies in tolerance grasping of various objects is needed. Ten healthy right-handed subjects were asked to perform the tolerance grasping with right hand using 6 objects of different shapes, sizes and relative positions between human hand and objects. Subjects were wearing CyberGlove attaching motion tracker on right hand, allowing a measurement of the hand and wrist postures. Correlation analysis of joints and inter-joint/inter-finger modules were carried on to explore the coordination between joints or modules. As the correlation between hand and wrist module is not obvious in tolerance grasping, individual analysis of wrist synergies would be more practical. In this case, postural synergies of hand and wrist were then presented separately through principal component analysis (PCA), expressed through the principal component (PC) information transmitted ratio, PC elements distribution and reconstructed angle error of joints. Results on correlation comparison of different module movements can be well explained by the influence factors of the joint movement correlation. Moreover, correlation analysis of joints and modules showed the wrist module had the lowest correlation among all inter-finger and inter-joint modules. Hand and wrist postures were both sufficient to be described by a few principal components. In terms of the PC elements distribution of hand postures, compared with previous investigations, there was a greater proportion of movement in the thumb joints especially the interphalangeal (IP) and opposition rotation (ROT) joint. The research could serve to a complete understanding of hand grasp, and the design, control of the anthropomorphic hand and wrist. PMID:27580298

Development of photoacoustic imaging system of finger vasculature using ring-shaped ultrasound transducer

NASA Astrophysics Data System (ADS)

Nishiyama, Misaki; Namita, Takeshi; Kondo, Kengo; Yamakawa, Makoto; Shiina, Tsuyoshi

2018-02-01

For early diagnosis of rheumatoid arthritis (RA), it is important to visualize its potential marker, vascularization in the synovial membrane of the finger joints. Photoacoustic (PA) imaging, which can image blood vessels at high contrast and resolution is expected to be a potential modality for earlier diagnosis of RA. In previous studies of PA finger imaging, different acoustic schemes such as linear or arc-shaped arrays have been utilized, but these have limited detection views, rendering inaccurate reconstruction, and most of them require rotational detection. We are developing a photoacoustic system for finger vascular imaging using a ring-shaped array ultrasound transducer. By designing the ring-array based on simulations and phantom experiments, we have created a system that can image multiple objects of different diameters and has the potential to image small objects 0.1-0.5mm in diameter at accurate positions by providing PA and ultrasound echo images simultaneously. In addition, we determined that full width at half maximum (FWHM) of the slice direction corresponded to that of the simulation. In the future, this system may visualize the 3-D vascularization of RA patients' fingers.

Case Report: The casting motion to mobilize stiffness technique for rehabilitation after a crush and degloving injury of the hand.

PubMed

Midgley, Robyn

2016-01-01

Case report. This case report describes the use of the casting motion to mobilize stiffness (CMMS) technique in the management of a crush and degloving injury of the hand. The patient was unable to attend multiple hand therapy sessions due to geographic constraints. The CMMS technique involved the application of a nonremovable plaster of paris cast that selectively immobilizes proximal joints in an ideal position while constraining distal joints to direct desired motion over a long period. This uses active motion only. Traditional hand therapy techniques or modalities are not used. This treatment approach was beneficial to the patient as a minimum of 2 appointments per month were needed to regain functional hand use. To document the use of the CMMS technique as an effective treatment approach in the management of a crush and degloving injury of the hand. The CMMS technique was applied to the patient's left (nondominant) hand 8 weeks after injury. The technique's aim was to improve the 30° flexion deformity of the left wrist and flexion contractures of the index, middle, and ring fingers with a total active motion of 0°. Orthotic devices and traditional therapy were applied once joint stiffness was resolved, and a normal pattern of motion was reinstated. At 6 months, substantial improvement was noted in wrist as well as metacarpophalangeal and interphalangeal joints. Total active motion exceeded 170° in all fingers excellent functional outcome resulted as measured with the upper limb functional index short form-10. The upper limb functional index increased from 0% to 55% of preinjury status (or capacity) over the 18 months of therapy. Brief immobilization through casting causes certain functional losses, but these are temporary and reversible. Finger stiffness, edema, and tissue fibrosis were successfully managed with the CMMS technique without the need for attendance at multiple hand therapy sessions. Level V. Copyright © 2016 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.

Influence of Prosthetic Screw Material on Joint Stability in Passive and Non-Passive Implant-Supported Dentures

PubMed Central

Spazzin, Aloísio Oro; Henriques, Guilherme Elias Pessanha; de Arruda Nóbilo, Mauro Antônio; Consani, Rafael Leonardo Xediek; Correr-Sobrinho, Lourenço; Mesquita, Marcelo Ferraz

2009-01-01

Objectives: This study evaluated the influence of prosthetic screw material on joint stability in implantsupported dentures at two levels of fit. Methods: Ten mandibular implant-supported dentures were fabricated. Twenty cast models were fabricated using these dentures. Four groups (n=10) were tested, according to the vertical fit of the dentures [passive and non-passive] and prosthetic screw materials [titanium (Ti) or gold (Au) alloy]. The one-screw test was performed to quantify the vertical misfits using an optic microscope. The loosening torque for the prosthetic screws was measured 24 hours after the tightening torque (10 Ncm) using a digital torque meter. Data were analyzed by two-way ANOVA and Tukey’s test (α=0.05). Results: Overall, dentures with passive fit and Ti screws resulted in significantly higher loosening torque of the prosthetic screws (p<0.05). No significant interaction was found between fit level and screw material (p=0.199). The prosthetic screw material and fit of implant-supported dentures have an influence on screw joint stability. Ti screws presented higher joint stability than Au screws and minimum of misfit should be found clinically to improve the mechanical behavior of the screw joint. PMID:20148135

Wear analysis and finishing of bioceramic implant surfaces.

PubMed

Denkena, Berend; Reichstein, Martin; van der Meer, Marijke; Ostermeier, Sven; Hurschler, Christof

2008-01-01

A primary cause for revision operations of joint replacements is the implant loosening, due to immune reactions resulting from the agglomeration of polyethylene wear debris. Motivated by the successful application of bioceramic materials in hip joint prostheses, a trend towards the development of hard implant materials has occurred. Nonetheless in the area of total knee arthroplasty (TKA), modern efforts have still utilized polyethylene as the tibial-inlay joint component. The use of bioceramic hard-hard-pairings for total knee arthroplasty has been prevented by the complex kinematics and geometries required. Ceramics cannot cope with non-uniform loads, which suggests the need for new designs appropriate to the material. Furthermore, biomechanical requirements should be considered. A rolling-gliding wear simulator, which reproduces the movements and stresses of the knee joint on specimens of simplified geometry, has therefore been developed. High-precision machining processes for free formed bioceramic surfaces, with suitable grinding and polishing tools which adjust to constantly changing contact conditions, are essential. The goal is to put automated finishing in one clamping with five simultaneous controlled axes into practice. The developed manufacturing technologies will allow the advantageous bioceramic materials to be applied and accepted for more complex joint replacements such as knee prostheses.

Vibration-Resistant Support for Halide Lamps

NASA Technical Reports Server (NTRS)

Kiss, J.

1987-01-01

Lamp envelope protected against breakage. Old and new mounts for halide arc lamp sealed in housing with parabolic refector and quartz window. New version supports lamp with compliant garters instead of rigid brazed joint at top and dimensionally unstable finger stock at bottom.

21 CFR 888.3100 - Ankle joint metal/composite semi-constrained cemented prosthesis.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ankle joint metal/composite semi-constrained... Ankle joint metal/composite semi-constrained cemented prosthesis. (a) Identification. An ankle joint metal/composite semi-constrained cemented prosthesis is a device intended to be implanted to replace an...

21 CFR 888.3510 - Knee joint femorotibial metal/polymer constrained cemented prosthesis.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint femorotibial metal/polymer constrained... Knee joint femorotibial metal/polymer constrained cemented prosthesis. (a) Identification. A knee joint femorotibial metal/polymer constrained cemented prosthesis is a device intended to be implanted to replace part...

21 CFR 888.3660 - Shoulder joint metal/polymer semi-constrained cemented prosthesis.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Shoulder joint metal/polymer semi-constrained... Shoulder joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. A shoulder joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a...

21 CFR 888.3650 - Shoulder joint metal/polymer non-constrained cemented prosthesis.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Shoulder joint metal/polymer non-constrained... Shoulder joint metal/polymer non-constrained cemented prosthesis. (a) Identification. A shoulder joint metal/polymer non-constrained cemented prosthesis is a device intended to be implanted to replace a...

21 CFR 888.3100 - Ankle joint metal/composite semi-constrained cemented prosthesis.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ankle joint metal/composite semi-constrained... Ankle joint metal/composite semi-constrained cemented prosthesis. (a) Identification. An ankle joint metal/composite semi-constrained cemented prosthesis is a device intended to be implanted to replace an...

Functional range of movement of the hand: declination angles to reachable space.

PubMed

Pham, Hai Trieu; Pathirana, Pubudu N; Caelli, Terry

2014-01-01

The measurement of the range of hand joint movement is an essential part of clinical practice and rehabilitation. Current methods use three finger joint declination angles of the metacarpophalangeal, proximal interphalangeal and distal interphalangeal joints. In this paper we propose an alternate form of measurement for the finger movement. Using the notion of reachable space instead of declination angles has significant advantages. Firstly, it provides a visual and quantifiable method that therapists, insurance companies and patients can easily use to understand the functional capabilities of the hand. Secondly, it eliminates the redundant declination angle constraints. Finally, reachable space, defined by a set of reachable fingertip positions, can be measured and constructed by using a modern camera such as Creative Senz3D or built-in hand gesture sensors such as the Leap Motion Controller. Use of cameras or optical-type sensors for this purpose have considerable benefits such as eliminating and minimal involvement of therapist errors, non-contact measurement in addition to valuable time saving for the clinician. A comparison between using declination angles and reachable space were made based on Hume's experiment on functional range of movement to prove the efficiency of this new approach.

Influence of abutment screw preload on stress distribution in marginal bone.

PubMed

Khraisat, Ameen

2012-01-01

Changes in an implant assembly after abutment connection might possibly cause deformation in the implant/abutment joint and even in the marginal bone. The aim of this study was to evaluate the influence of abutment screw preload through the implant collar on marginal bone stress without external load application. Models of three implant parts made of titanium (implant, abutment, and abutment screw) and cortical bone were built and positioned with computer-aided design software. Meshing and generation of boundary conditions, loads, and interactions were performed. Each part was meshed independently. The sole load applied to the model was a torque of 32 Ncm on the abutment screw about its axis of rotation. The implant collar was deformed axially after the screw was tightened (3 μm). This deformation resulted in 60 MPa of stress in the marginal bone. Moreover, pressure on the marginal bone in a radial direction was observed. It can be concluded that, without any external load application, abutment screw preload exerts stresses on the implant collar and the marginal bone. These findings should help guide the development of new implant/abutment joint designs that exert less stress on the marginal bone.

Orthopedic implant devices: prevalence and sociodemographic findings from the 1988 National Health Interview Survey.

PubMed

Moore, R M; Hamburger, S; Jeng, L L; Hamilton, P M

1991-01-01

National population-based estimates on the magnitude and distribution of orthopedic implant devices in the United States have not been available to date. The Food and Drug Administration's Center for Devices and Radiological Health (FDA/CDRH) collaborated with the Centers for Disease Control's National Center for Health Statistics (CDC/NCHS) in the design and conduct of a nationwide medical device implant survey to generate the first national population-based prevalence estimates of orthopedic implant devices. A Medical Device Implant Supplement to the 1988 National Health Interview Survey was administered in personal household interviews to a national sample of 47,485 households, which included 122,310 individuals. An estimated 6.5 million orthopedic implants were in use in the general US population in 1988, including 1.6 million artificial joints and 4.9 million fixation devices. As a group, orthopedic implants comprised nearly half of all medical device implants in use, 43.4%. The majority of artificial joint recipients were 65 years of age or older, white, and male. The majority of fixation device recipients were less than 45 years of age, white, and male. The limitations and strengths of these population-based estimates are discussed.

Acinetobacter Prosthetic Joint Infection Treated with Debridement and High-Dose Tigecycline.

PubMed

Vila, Andrea; Pagella, Hugo; Amadio, Claudio; Leiva, Alejandro

2016-12-01

Prosthesis retention is not recommended for multidrug-resistant Acinetobacter prosthetic joint infection due to its high failure rate. Nevertheless, replacing the prosthesis implies high morbidity and prolonged hospitalization. Although tigecycline is not approved for the treatment of prosthetic joint infection due to multidrug resistant Acinetobacter baumannii, its appropriate use may preclude prosthesis exchange. Since the area under the curve divided by the minimum inhibitory concentration is the best pharmacodynamic predictor of its efficacy, we used tigecycline at high dose, in order to optimize its efficacy and achieve implant retention in 3 patients who refused prosthesis exchange. All patients with prosthetic joint infections treated at our Institution are prospectively registered in a database. Three patients with early prosthetic joint infection of total hip arthroplasty due to multidrug resistant A. baumannii were treated with debridement, antibiotics and implant retention, using a high maintenance dose of tigecycline (100 mg every 12 hours). The cases were retrospectively reviewed. All patients signed informed consent for receiving off-label use of tigecycline. Tigecycline was well tolerated, allowing its administration at high maintenance dose for a median of 40 days (range 30-60). Two patients were then switched to minocycline at standard doses for a median of 3.3 months in order to complete treatment. Currently, none of the patients showed relapse. Increasing the dose of tigecycline could be considered as a means to better attain pharmacodynamic targets in patients with severe or difficult-to-treat infections. Tigecycline at high maintenance dose might be useful when retention of the implant is attempted for treatment for prosthetic joint infections due to multidrug resistant Acinetobacter. Although this approach might be promising, off-label use of tigecycline should be interpreted cautiously until prospective data are available. Tigecycline is probably under-dosed for the treatment of implant and biofilm associated infections.

Splint therapy for trigger finger in children.

PubMed

Tsuyuguchi, Y; Tada, K; Kawaii, H

1983-02-01

During the last 9 years, 83 trigger digits in 65 children were treated using a modified coil spring splint which maintains the interphalangeal (IP) joint in neutral extension or hyperextension. Sixty-two digits (75%) were completely healed following splint therapy alone, after an average period of splinting for 9.4 months. Eight digits which did not improve with splinting were surgically treated. Splint therapy to maintain the IP joint in neutral extension or hyperextension proved markedly effective in our series.

Intramedullary Percutaneous Fixation of Extra-Articular Proximal and Middle Phalanx Fractures.

PubMed

Jovanovic, Nebojsa; Aldlyami, Ehab; Saraj, Basem; Fm Seidam, Mohamed; Badawi, Hamed; Shaat, Ahmed; Alawadi, Khalid; Dodakundi, Chaitanya

2018-06-01

Multiple methods have been described for treating unstable proximal and middle phalangeal fractures. Irrespective of using an open or closed technique of fixation, stiffness and extensor lag at the proximal/distal interphalangeal joint almost always occur. This issue can be avoided by allowing the patients to mobilize the fingers out of plaster or splint as early as possible from the day of surgery. We describe a technique of intramedullary percutaneous fixation of extra-articular proximal and middle phalanx fractures allowing immediate mobilization of fingers, concurrent stabilization with progressive healing and thus preventing such complications.

[Pulley for strengthening a muscle replacement operation across two joints in brachial plexus lesion: description of the surgical technique].

PubMed

Berger, A; Schaller, E; Becker, M H

1994-01-01

The reconstruction of lost muscle functions in cases of brachial plexus lesion is possible even in those cases where primary nerve reconstruction was not performed or unsuccessful. If there are only few motor nerves available, we prefer free latissimus dorsi transplantation or pedicled latissimus dorsi transposition for replacement of biceps and finger flexors. The combination of elbow flexion and finger flexion becomes possible when the transposed motor is passed around a suitable pulley in the elbow region like the flexor carpi ulnaris or carpi radialis.

Knuckle Pads—A common problem but good to treat by Laser

NASA Astrophysics Data System (ADS)

Herold, Manfred; Russe-Wilflingseder, Katharina

2010-05-01

Knuckle pads are common skin lesions not disease associated and seen as thickended skin like nodules situated usually on the dorsal site of the proximal interphalangeal joints. Neither medical nor surgical procedures are very effective to remove knuckle pads. A women 22 years of age with knuckle pads on the fingers two and three on both hands which reoccurred after surgical resections was successful treated with a long pulsed Erbium:YAG laser. All four fingers were ablated within one single treatment. The aesthetic result was excellent and lasted at least for 18 months.

Exploring social influences on the joint Simon task: empathy and friendship

PubMed Central

Ford, Ruth M.; Aberdein, Bradley

2015-01-01

Tasks for which people must act together to achieve a goal are a feature of daily life. The present study explored social influences on joint action using a Simon procedure for which participants (n = 44) were confronted with a series of images of hands and asked to respond via button press whenever the index finger wore a ring of a certain color (red or green) regardless of pointing direction (left or right). In an initial joint condition they performed the task while sitting next to another person (friend or stranger) who responded to the other color. In a subsequent individual condition they repeated the task on their own; additionally, they completed self-report tests of empathy. Consistent with past research, participants reacted more quickly when the finger pointed toward them rather than their co-actor (the Simon Effect or SE). The effect remained robust when the co-actor was no longer present and was unaffected by degree of acquaintance; however, its magnitude was correlated positively with empathy only among friends. For friends, the SE was predicted by cognitive perspective taking when the co-actor was present and by propensity for fantasizing when the co-actor was absent. We discuss these findings in relation to social accounts (e.g., task co-representation) and non-social accounts (e.g., referential coding) of joint action. PMID:26217281

Influence of prosthesis design and implantation technique on implant stresses after cementless revision THR

PubMed Central

2011-01-01

Background Femoral offset influences the forces at the hip and the implant stresses after revision THR. For extended bone defects, these forces may cause considerable bending moments within the implant, possibly leading to implant failure. This study investigates the influences of femoral anteversion and offset on stresses in the Wagner SL revision stem implant under varying extents of bone defect conditions. Methods Wagner SL revision stems with standard (34 mm) and increased offset (44 mm) were virtually implanted in a model femur with bone defects of variable extent (Paprosky I to IIIb). Variations in surgical technique were simulated by implanting the stems each at 4° or 14° of anteversion. Muscle and joint contact forces were applied to the reconstruction and implant stresses were determined using finite element analyses. Results Whilst increasing the implant's offset by 10 mm led to increased implant stresses (16.7% in peak tensile stresses), altering anteversion played a lesser role (5%). Generally, larger stresses were observed with reduced bone support: implant stresses increased by as much as 59% for a type IIIb defect. With increased offset, the maximum tensile stress was 225 MPa. Conclusion Although increased stresses were observed within the stem with larger offset and increased anteversion, these findings indicate that restoration of offset, key to restoring joint function, is unlikely to result in excessive implant stresses under routine activities if appropriate fixation can be achieved. PMID:21569522

Fluorescence and UV-vis Spectroscopy of Synovial Fluids

NASA Astrophysics Data System (ADS)

Pinti, Marie J.; Stojilovic, Nenad; Kovacik, Mark W.

2009-10-01

Total joint arthroplasty involves replacing the worn cartilaginous surfaces of the joint with man-made materials that are designed to be biocompatible and to withstand mechanical stresses. Commonly these bearing materials consist of metallic alloys (TiAlV or CoCrMo) and UHMWPE. Following joint arthroplasty, the normal generation of micro-metallic wear debris particles that dislodge from the prosthesis has been shown to cause inflammatory aseptic osteolysis (bone loss) that ultimately results in the failure of the implant. Here we report our results on the novel use of Fluorescence and UV-vis spectroscopy to investigate the metallic content of synovial fluid specimens taken from postoperative total knee arthroplasties. Preliminary finding showed presence of alumina and chromium is some specimens. The ability to detect and monitor the wear rate of these implants could have far reaching implications in the prevention of metallic wear-debris induced osteolysis and impending implant failure.

Development and application of biomimetic electrospun nanofibers in total joint replacement

NASA Astrophysics Data System (ADS)

Song, Wei

Failure of osseointegration (direct anchorage of an implant by bone formation at the bone-implant surface) and implant infection (such as that caused by Staphylococcus aureus, S. aureus) are the two main causes of implant failure and loosening. There is a critical need for orthopedic implants that promote rapid osseointegration and prevent bacterial colonization, particularly when placed in bone compromised by disease or physiology of the patients. A better understanding of the key factors that influence cell fate decisions at the bone-implant interface is required. Our study is to develop a class of "bone-like" nanofibers (NFs) that promote osseointegration while preventing bacterial colonization and subsequent infections. This research goal is supported by our preliminary data on the preparation of coaxial electrospun NFs composed of polycaprolactone (PCL) and polyvinyl alcohol (PVA) polymers arranged in a core-sheath shape. The PCL/PVA NFs are biocompatible and biodegradable with appropriate fiber diameter, pore size and mechanical strength, leading to enhanced cell adhesion, proliferation and differentiation of osteoblast precursor cells. The objective is to develop functionalized "bone-like" PCL/PVA NFs matrix embedded with antibiotics (doxycycline (Doxy), bactericidal and anti-osteoclastic) on prosthesis surface. Through a rat tibia implantation model, the Doxy incorporated coaxial NFs has demonstrated excellent in promoting osseointegration and bacteria inhibitory efficacy. NFs coatings significantly enhanced the bonding between implant and bone remodeling within 8 weeks. The SA-induced osteomyelitis was prevented by the sustained release of Doxy from NFs. The capability of embedding numerous bio-components including proteins, growth factors, drugs, etc. enables NFs an effective solution to overcome the current challenged issue in Total joint replacement. In summary, we proposed PCL/PVA electrospun nanofibers as promising biomaterials that can be applied on joint replacement prosthesis to improve osseointegration and prevent osteomyelitis.

Percutaneous Kirschner Wire Versus Commercial Implant for Hammertoe Repair: A Cost-Effectiveness Analysis.

PubMed

Albright, Rachel H; Waverly, Brett J; Klein, Erin; Weil, Lowell; Weil, Lowell S; Fleischer, Adam E

Hammertoe deformities are one of the most common foot deformities, affecting up to one third of the general population. Fusion of the joint can be achieved with various devices, with the current focus on percutaneous Kirschner (K)-wire fixation or commercial intramedullary implant devices. The purpose of the present study was to determine whether surgical intervention with percutaneous K-wire fixation versus commercial intramedullary implant is more cost effective for proximal interphalangeal joint arthrodesis in hammertoe surgery. A formal cost-effectiveness analysis using a decision analytic tree model was conducted to investigate the healthcare costs and outcomes associated with either K-wire or commercial intramedullary implant fixation. The outcomes assessed included long-term costs, quality-adjusted life-years (QALYs), and incremental cost per QALY gained. Costs were evaluated from the healthcare system perspective and are expressed in U.S. dollars at a 2017 price base. Our results found that commercial implants were minimally more effective than K-wires but carried significantly higher costs. The total cost for treatment with percutaneous K-wire fixation was $5041 with an effectiveness of 0.82 QALY compared with a commercial implant cost of $6059 with an effectiveness of 0.83 QALY. The incremental cost-effectiveness ratio of commercial implants was $146,667. With an incremental cost-effectiveness ratio of >$50,000, commercial implants failed to justify their proposed benefits to outweigh their cost compared to percutaneous K-wire fixation. In conclusion, percutaneous K-wire fixation would be preferred for arthrodesis of the proximal interphalangeal joint for hammertoes from a healthcare system perspective. Copyright © 2017 The American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Chronic recording of hand prosthesis control signals via a regenerative peripheral nerve interface in a rhesus macaque

NASA Astrophysics Data System (ADS)

Irwin, Z. T.; Schroeder, K. E.; Vu, P. P.; Tat, D. M.; Bullard, A. J.; Woo, S. L.; Sando, I. C.; Urbanchek, M. G.; Cederna, P. S.; Chestek, C. A.

2016-08-01

Objective. Loss of even part of the upper limb is a devastating injury. In order to fully restore natural function when lacking sufficient residual musculature, it is necessary to record directly from peripheral nerves. However, current approaches must make trade-offs between signal quality and longevity which limit their clinical potential. To address this issue, we have developed the regenerative peripheral nerve interface (RPNI) and tested its use in non-human primates. Approach. The RPNI consists of a small, autologous partial muscle graft reinnervated by a transected peripheral nerve branch. After reinnervation, the graft acts as a bioamplifier for descending motor commands in the nerve, enabling long-term recording of high signal-to-noise ratio (SNR), functionally-specific electromyographic (EMG) signals. We implanted nine RPNIs on separate branches of the median and radial nerves in two rhesus macaques who were trained to perform cued finger movements. Main results. No adverse events were noted in either monkey, and we recorded normal EMG with high SNR (>8) from the RPNIs for up to 20 months post-implantation. Using RPNI signals recorded during the behavioral task, we were able to classify each monkey’s finger movements as flexion, extension, or rest with >96% accuracy. RPNI signals also enabled functional prosthetic control, allowing the monkeys to perform the same behavioral task equally well with either physical finger movements or RPNI-based movement classifications. Significance. The RPNI signal strength, stability, and longevity demonstrated here represents a promising method for controlling advanced prosthetic limbs and fully restoring natural movement.

Chronic recording of hand prosthesis control signals via a regenerative peripheral nerve interface in a rhesus macaque.

PubMed

Irwin, Z T; Schroeder, K E; Vu, P P; Tat, D M; Bullard, A J; Woo, S L; Sando, I C; Urbanchek, M G; Cederna, P S; Chestek, C A

2016-08-01

Loss of even part of the upper limb is a devastating injury. In order to fully restore natural function when lacking sufficient residual musculature, it is necessary to record directly from peripheral nerves. However, current approaches must make trade-offs between signal quality and longevity which limit their clinical potential. To address this issue, we have developed the regenerative peripheral nerve interface (RPNI) and tested its use in non-human primates. The RPNI consists of a small, autologous partial muscle graft reinnervated by a transected peripheral nerve branch. After reinnervation, the graft acts as a bioamplifier for descending motor commands in the nerve, enabling long-term recording of high signal-to-noise ratio (SNR), functionally-specific electromyographic (EMG) signals. We implanted nine RPNIs on separate branches of the median and radial nerves in two rhesus macaques who were trained to perform cued finger movements. No adverse events were noted in either monkey, and we recorded normal EMG with high SNR (>8) from the RPNIs for up to 20 months post-implantation. Using RPNI signals recorded during the behavioral task, we were able to classify each monkey's finger movements as flexion, extension, or rest with >96% accuracy. RPNI signals also enabled functional prosthetic control, allowing the monkeys to perform the same behavioral task equally well with either physical finger movements or RPNI-based movement classifications. The RPNI signal strength, stability, and longevity demonstrated here represents a promising method for controlling advanced prosthetic limbs and fully restoring natural movement.

Comparative Microstrain Study of Internal Hexagon and Plateau Design of Short Implants Under Vertical Loading.

PubMed

Nishioka, Renato Sussumu; Rodrigues, Vinicius Anéas; De Santis, Leandro Ruivo; Nishioka, Gabriela Nogueira De Melo; Santos, Vivian Mayumi Miyazaki; Souza, Francisley Ávila

2016-02-01

To quantify microstrain development during axial loading using strain gauge analysis for short implants, varying the type of fixture-abutment joint and thread design. An internal hexagon implant (4 × 8 mm) and a plateau design implant (4 × 8 mm) were embedded on the center of 10 polyurethane blocks with dimensions of 190 × 30 × 12 mm. The respective abutments were screwed onto the implants. Four strain gauges (SGs) were bonded onto the surface of each block, and 4 vertical SGs were bonded onto the side of each block. Axial load of 30 kgf was applied for 10 seconds in the center of each implant. The data were analyzed statistically by analysis of variance for repeated measures and Tukey test (P < 0.05). The interaction between implant and region factors have been statistically significant (P = 0.0259). Tukey test revealed a difference on plateau's horizontal region. The cervical region presented higher microstrain values, when compared with the medium and apical regions of the implants. Within the purpose of the study, the type of fixture-abutment joint is a relevant factor to affect the amount of stress/strain in bone simulation. The microstrain development was concentrated on the cervical region of the implant.

Dubious space for Artelon joint resurfacing for basal thumb (trapeziometacarpal joint) osteoarthritis. A systematic review.

PubMed

Smeraglia, Francesco; Mariconda, Massimo; Balato, Giovanni; Di Donato, Sigismondo Luca; Criscuolo, Giovanni; Maffulli, Nicola

2018-06-01

Trapeziometacarpal arthritis is a common and disabling condition. There is no evidence in the literature of superiority of one surgical procedure over others. Several prosthetic implants have been introduced to preserve joint mobility. We searched the on Medline (PubMed), Web of Science and Scopus databases using the combined keywords 'artelon', 'thumb', 'carpometacarpal', 'trapeziometacarpal' and 'rhizoarthrosis'; 11 studies were identified. The use of Artelon implant is not recommended because of its high revision rate and worse outcomes compared to conventional techniques. Inert materials subjected to compressive and shearing forces could produce debris and subsequent inflammatory response. There is debate in the published scientific literature regarding the role of preoperative antibiotic profilaxis and post-surgery inflammatory response. Standard techniques such as trapeziectomy alone or combined with interposition or suspensionplasty offer effective treatment for thumb basal joint arthritis. Several prosthetic implants show promising results in terms of pain relief and functional request, but there is a need of long-term randomized controlled trials to demonstrate their equivalence, and eventually superiority, compared to standard techniques.

21 CFR 888.3370 - Hip joint (hemi-hip) acetabular metal cemented prosthesis.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Hip joint (hemi-hip) acetabular metal cemented... (hemi-hip) acetabular metal cemented prosthesis. (a) Identification. A hip joint (hemi-hip) acetabular metal cemented prosthesis is a device intended to be implanted to replace a portion of the hip joint...

21 CFR 888.3310 - Hip joint metal/polymer constrained cemented or uncemented prosthesis.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Hip joint metal/polymer constrained cemented or... Hip joint metal/polymer constrained cemented or uncemented prosthesis. (a) Identification. A hip joint metal/polymer constrained cemented or uncemented prosthesis is a device intended to be implanted to...

21 CFR 888.3110 - Ankle joint metal/polymer semi-constrained cemented prosthesis.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ankle joint metal/polymer semi-constrained... Ankle joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. An ankle joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an ankle...

21 CFR 888.3160 - Elbow joint metal/polymer semi-constrained cemented prosthesis.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Elbow joint metal/polymer semi-constrained... Elbow joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. An elbow joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an elbow...

21 CFR 888.3310 - Hip joint metal/polymer constrained cemented or uncemented prosthesis.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hip joint metal/polymer constrained cemented or... Hip joint metal/polymer constrained cemented or uncemented prosthesis. (a) Identification. A hip joint metal/polymer constrained cemented or uncemented prosthesis is a device intended to be implanted to...

21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be implanted...

21 CFR 888.3340 - Hip joint metal/composite semi-constrained cemented prosthesis.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hip joint metal/composite semi-constrained... Hip joint metal/composite semi-constrained cemented prosthesis. (a) Identification. A hip joint metal/composite semi-constrained cemented prosthesis is a two-part device intended to be implanted to replace a...

21 CFR 888.3310 - Hip joint metal/polymer constrained cemented or uncemented prosthesis.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Hip joint metal/polymer constrained cemented or... Hip joint metal/polymer constrained cemented or uncemented prosthesis. (a) Identification. A hip joint metal/polymer constrained cemented or uncemented prosthesis is a device intended to be implanted to...

21 CFR 888.3110 - Ankle joint metal/polymer semi-constrained cemented prosthesis.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ankle joint metal/polymer semi-constrained... Ankle joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. An ankle joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an ankle...

21 CFR 888.3160 - Elbow joint metal/polymer semi-constrained cemented prosthesis.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Elbow joint metal/polymer semi-constrained... Elbow joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. An elbow joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an elbow...

21 CFR 888.3110 - Ankle joint metal/polymer semi-constrained cemented prosthesis.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ankle joint metal/polymer semi-constrained... Ankle joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. An ankle joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an ankle...

21 CFR 888.3310 - Hip joint metal/polymer constrained cemented or uncemented prosthesis.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Hip joint metal/polymer constrained cemented or... Hip joint metal/polymer constrained cemented or uncemented prosthesis. (a) Identification. A hip joint metal/polymer constrained cemented or uncemented prosthesis is a device intended to be implanted to...

21 CFR 888.3160 - Elbow joint metal/polymer semi-constrained cemented prosthesis.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Elbow joint metal/polymer semi-constrained... Elbow joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. An elbow joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an elbow...

21 CFR 888.3160 - Elbow joint metal/polymer semi-constrained cemented prosthesis.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Elbow joint metal/polymer semi-constrained... Elbow joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. An elbow joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an elbow...

21 CFR 888.3310 - Hip joint metal/polymer constrained cemented or uncemented prosthesis.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Hip joint metal/polymer constrained cemented or... Hip joint metal/polymer constrained cemented or uncemented prosthesis. (a) Identification. A hip joint metal/polymer constrained cemented or uncemented prosthesis is a device intended to be implanted to...

21 CFR 888.3110 - Ankle joint metal/polymer semi-constrained cemented prosthesis.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ankle joint metal/polymer semi-constrained... Ankle joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. An ankle joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an ankle...

Open extensor tendon injuries: an epidemiologic study.

PubMed

Patillo, Dominic; Rayan, Ghazi M

2012-01-01

To report the epidemiology, mechanism, anatomical location, distribution, and severity of open extensor tendon injuries in the digits, hand, and forearm as well as the frequency of associated injuries to surrounding bone and soft tissue. Retrospective chart review was conducted for patients who had operative repair of open digital extensor tendon injuries in all zones within an 11-year period. Data was grouped according to patient characteristics, zone of injury, mechanism of injury, and presence of associated injury. Statistical analysis was used to determine the presence of relevant associations. Eighty-six patients with 125 severed tendons and 105 injured digits were available for chart reviews. Patients were predominantly males (83%) with a mean age of 34.2 years and the dominant extremity was most often injured (60%). The thumb was the most commonly injured (25.7%), followed by middle finger (24.8), whereas small finger was least affected (10.5%). Sharp laceration was the most common mechanism of injury (60%), and most of these occurred at or proximal to the metacarpophalangeal joints. Most saw injuries occurred distal to the metacarpophalangeal joint. Zone V was the most commonly affected in the fingers (27%) while zone VT was the most commonly affected in the thumb (69%). Associated injuries to bone and soft tissue occurred in 46.7% of all injuries with saw and crush/avulsions being predictive of fractures and damage to the underlying joint capsule. The extensor mechanism is anatomically complex, and open injuries to the dorsum of the hand, wrist, and forearm, especially of crushing nature and those inflicted by saws, must be thoroughly evaluated. Associated injuries should be ruled out in order to customize surgical treatment and optimize outcome.

[A comparison of time resolution among auditory, tactile and promontory electrical stimulation--superiority of cochlear implants as human communication aids].

PubMed

Matsushima, J; Kumagai, M; Harada, C; Takahashi, K; Inuyama, Y; Ifukube, T

1992-09-01

Our previous reports showed that second formant information, using a speech coding method, could be transmitted through an electrode on the promontory. However, second formant information can also be transmitted by tactile stimulation. Therefore, to find out whether electrical stimulation of the auditory nerve would be superior to tactile stimulation for our speech coding method, the time resolutions of the two modes of stimulation were compared. The results showed that the time resolution of electrical promontory stimulation was three times better than the time resolution of tactile stimulation of the finger. This indicates that electrical stimulation of the auditory nerve is much better for our speech coding method than tactile stimulation of the finger.

A simplified technique for polymethyl methacrylate cranioplasty: combined cotton stacking and finger fracture method.

PubMed

Kung, Woon-Man; Lin, Muh-Shi

2012-01-01

Polymethyl methacrylate (PMMA) is one of the most frequently used cranioplasty materials. However, limitations exist with PMMA cranioplasty including longer operative time, greater blood loss and a higher infection rate. To reduce these disadvantages, it is proposed to introduce a new surgical method for PMMA cranioplasty. Retrospective review of nine patients who received nine PMMA implants using combined cotton stacking and finger fracture method from January 2008 to July 2011. The definitive height of skull defect was quantified by computer-based image analysis of computed tomography (CT) scans. Aesthetic outcomes as measured by post-reduction radiographs and cranial index of symmetry (CIS), cranial nerve V and VII function and complications (wound infection, hardware extrusions, meningitis, osteomyelitis and brain abscess) were evaluated. The mean operation time for implant moulding was 24.56 ± 4.6 minutes and 178.0 ± 53 minutes for skin-to-skin. Average blood loss was 169 mL. All post-operative radiographs revealed excellent reduction. The mean CIS score was 95.86 ± 1.36%, indicating excellent symmetry. These results indicate the safety, practicability, excellent cosmesis, craniofacial symmetry and stability of this new surgical technique.

Detection of orthopaedic foot and ankle implants by security screening devices.

PubMed

Bluman, Eric M; Tankson, Cedric; Myerson, Mark S; Jeng, Clifford L

2006-12-01

A common question asked by patients contemplating foot and ankle surgery is whether the implants used will set off security screening devices in airports and elsewhere. Detectability of specific implants may require the orthopaedic surgeon to provide attestation regarding their presence in patients undergoing implantation of these devices. Only two studies have been published since security measures became more stringent in the post-9/11 era. None of these studies specifically focused on the large numbers of orthopaedic foot and ankle implants in use today. This study establishes empiric data on the detectability by security screening devices of some currently used foot and ankle implants. A list of foot and ankle procedures was compiled, including procedures frequently used by general orthopaedists as well as those usually performed only by foot and ankle specialists. Implants tested included those used for open reduction and internal fixation, joint fusion, joint arthroplasty, osteotomies, arthroreisis, and internal bone stimulation. A test subject walked through a gate-type security device and was subsequently screened using a wand-type detection device while wearing each construct grouping. The screening was repeated with the implants placed within uncooked steak to simulate subcutaneous and submuscular implantation. None of the implants were detected by the gate-type security device. Specific implants that triggered the wand-type detection device regardless of coverage with the meat were total ankle prostheses, implantable bone stimulators, large metatarsophalangeal hemiarthroplasty, large arthroreisis plugs, medial distal tibial locking construct, supramalleolar osteotomy fixation, stainless steel bimalleolar ankle fracture fixation, calcaneal fracture plate and screw constructs, large fragment blade plate constructs, intramedullary tibiotalocalcaneal fusion constructs, and screw fixation for calcaneal osteotomies, ankle arthrodeses, triple arthrodeses, and stainless steel first metatarsophalangeal joint arthrodeses. The placement of implants in meat prevented the detectability of only the stainless steel Jones fracture implant (stainless steel 6.5-mm cannulated screw) and the stainless steel midfoot fusion construct (four stainless steel 4.0-mm cannulated screws). These data may help the orthopaedic surgeon in counseling patients as to the detectability of some orthopaedic foot and ankle implants in use today. Specific constructs for which documentation may need to be provided to the patient are identified. As security standards evolve and the environments in which they are practiced change, empiric testing of many of these devices may need to be repeated.

Talbot phase-contrast X-ray imaging for the small joints of the hand

PubMed Central

Stutman, Dan; Beck, Thomas J; Carrino, John A; Bingham, Clifton O

2011-01-01

A high resolution radiographic method for soft tissues in the small joints of the hand would aid in the study and treatment of Rheumatoid Arthritis (RA) and Osteoarthritis (OA), which often attacks these joints. Of particular interest would be imaging with <100 μm resolution the joint cartilage, whose integrity is a main indicator of disease. Differential phase-contrast or refraction based X-ray imaging (DPC) with Talbot grating interferometers could provide such a method, since it enhances soft tissue contrast and it can be implemented with conventional X-ray tubes. A numerical joint phantom was first developed to assess the angular sensitivity and spectrum needed for a hand DPC system. The model predicts that due to quite similar refraction indexes for joint soft tissues, the refraction effects are very small, requiring high angular resolution. To compare our model to experiment we built a high resolution bench-top interferometer using 10 μm period gratings, a W anode tube and a CCD based detector. Imaging experiments on animal cartilage and on a human finger support the model predictions. For instance, the estimated difference between the index of refraction of cartilage and water is of only several percent at ~25 keV mean energy, comparable to that between the linear attenuation coefficients. The potential advantage of DPC imaging comes thus mainly from the edge enhancement at the soft tissue interfaces. Experiments using a cadaveric human finger are also qualitatively consistent with the joint model, showing that refraction contrast is dominated by tendon embedded in muscle, with the cartilage layer difficult to observe in our conditions. Nevertheless, the model predicts that a DPC radiographic system for the small hand joints of the hand could be feasible using a low energy quasi-monochromatic source, such as a K-edge filtered Rh or Mo tube, in conjunction with a ~2 m long ‘symmetric’ interferometer operated in a high Talbot order. PMID:21841214

Talbot phase-contrast x-ray imaging for the small joints of the hand

NASA Astrophysics Data System (ADS)

Stutman, Dan; Beck, Thomas J.; Carrino, John A.; Bingham, Clifton O.

2011-09-01

A high-resolution radiographic method for soft tissues in the small joints of the hand would aid in the study and treatment of rheumatoid arthritis (RA) and osteoarthritis (OA), which often attacks these joints. Of particular interest would be imaging with <100 µm resolution the joint cartilage, whose integrity is a main indicator of disease. Differential phase-contrast (DPC) or refraction-based x-ray imaging with Talbot grating interferometers could provide such a method, since it enhances soft tissue contrast and can be implemented with conventional x-ray tubes. A numerical joint phantom was first developed to assess the angular sensitivity and spectrum needed for a hand DPC system. The model predicts that, due to quite similar refraction indexes for joint soft tissues, the refraction effects are very small, requiring high angular resolution. To compare our model to experiment we built a high-resolution bench-top interferometer using 10 µm period gratings, a W anode tube and a CCD-based detector. Imaging experiments on animal cartilage and on a human finger support the model predictions. For instance, the estimated difference between the index of refraction of cartilage and water is of only several percent at ~25 keV mean energy, comparable to that between the linear attenuation coefficients. The potential advantage of DPC imaging thus comes mainly from the edge enhancement at the soft tissue interfaces. Experiments using a cadaveric human finger are also qualitatively consistent with the joint model, showing that refraction contrast is dominated by tendon embedded in muscle, with the cartilage layer difficult to observe in our conditions. Nevertheless, the model predicts that a DPC radiographic system for the small hand joints of the hand could be feasible using a low energy quasi-monochromatic source, such as a K-edge filtered Rh or Mo tube, in conjunction with a ~2 m long 'symmetric' interferometer operated in a high Talbot order.

[Juvenile rheumatoid diseases: Endoprosthetic care of destroyed hip joints].

PubMed

Rehart, S; Henniger, M

2015-07-01

Patients with juvenile idiopathic arthritis (JIA) often suffer from involvement of the hip joints, with joint destruction and related functional limitations, making hip replacement necessary. To discover what special features are to be expected in patients with JIA and hip arthroplasty and what impact they have on surgical indication, choice of implant, and technique. Selective literature review and evaluation of our patient population. Compared with osteoarthritis patients, JIA patients are on average much younger at the time of hip replacement. Owing to the onset of the disease in childhood or adolescence and the frequent glucocorticoid therapy, growth disorders or abnormal anatomical findings are common in these patients. Bone density is often reduced at an early age. The perioperative management of medication has to be planned. Special implants for patients with rheumatic diseases do not exist, but the above peculiarities of this group of patients should be considered for surgical procedure and choice of implant and material. Overall, the results of hip arthroplasty in juvenile rheumatic diseases, in terms of pain relief and functional improvement, are good. The limited life of the arthroplasty is problematic. By relieving pain, improvement of the range of motion and activity level very high patient satisfaction is usually achieved by hip arthroplasty in JIA patients. In the case of involvement of the contralateral hip or the ipsilateral knee joint it may be useful to perform a simultaneous, single-stage joint replacement of both joints.

A new three-dimensional, print-on-demand temporomandibular prosthetic total joint replacement system: Preliminary outcomes.

PubMed

Dimitroulis, George; Austin, Stephen; Sin Lee, Peter Vee; Ackland, David

2018-05-16

The aim of this study is to present the preliminary clinical data on the OMX Temporomandibular Joint (TMJ) Prosthetic total joint replacement system. A prospective, cohort, clinical study was undertaken of consecutive adult patients with Category 5 end-stage joint disease who were implanted with the OMX TMJ prosthesis between May 2015 and April 2017. A total of 50 devices were implanted in 38 patients, with 12 patients receiving bilateral prosthetic joints. There were 31 females and 7 males in this cohort, who ranged in age from 20 to 66 years, with a mean of 43.8 years (±14.0 years). Ten of the 50 prosthetic joints (20%) were fully customized, while the remaining were patient matched using virtual planning software. Based on a mean follow-up period of 15.3 months (range 12-24 months) following the TMJ total joint replacement, preliminary results suggest the OMX TMJ prosthesis has made a positive impact on clinical outcomes, with a mean 74.4% reduction in joint pain levels and significant improvements (p < 0.05) in jaw function as measured by the visual analogue scales for mouth opening (30.8%), diet (77.1%), and function (59.2%). No device failures were reported during the study period. This study suggests that the print-on-demand OMX TMJ prosthesis, designed for rapid delivery of both patient-matched and fully customize devices, represents a safe, reliable and versatile implantable joint replacement system for the treatment of category 5 end-stage TMJ disease. Copyright © 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Horizontal slip along Alleghanian joints of the Appalachian plateau: evidence showing that mild penetrative strain does little to change the pristine appearance of early joints

NASA Astrophysics Data System (ADS)

Engelder, Terry; Haith, Benjamin F.; Younes, Amgad

2001-07-01

Some Alleghanian joints in black shales of the Geneseo and Middlesex Formations of the Catskill Delta complex, Finger Lakes district, New York, slipped horizontally up to 8 cm. Horizontal slip is measured by the offset of ENE-striking joints. Alleghanian joints striking 330-350° display a right-lateral slip with an average value of 1.9 cm, while joints striking 004-010° slip in the left-lateral sense with an average value of 1.3 cm. The maximum horizontal stress (SH) driving this slip falls between 350° and 004°, the orientation of local Alleghanian layer-parallel shortening as indicated by both disjunctive and pencil cleavage. By commonality of orientation, we infer that slip on Alleghanian joints is driven contemporaneously with layer-parallel shortening. If so, the offset ENE-striking joints predate the Alleghanian stress field. These observations mean that both pre-Alleghanian and early Alleghanian joints persist through a period of penetrative strain.

Tribological performance of the biological components of synovial fluid in artificial joint implants

NASA Astrophysics Data System (ADS)

Ghosh, Subir; Choudhury, Dipankar; Roy, Taposh; Moradi, Ali; Masjuki, H. H.; Pingguan-Murphy, Belinda

2015-08-01

The concentration of biological components of synovial fluid (such as albumin, globulin, hyaluronic acid, and lubricin) varies between healthy persons and osteoarthritis (OA) patients. The aim of the present study is to compare the effects of such variation on tribological performance in a simulated hip joint model. The study was carried out experimentally by utilizing a pin-on-disk simulator on ceramic-on-ceramic (CoC) and ceramic-on-polyethylene (CoP) hip joint implants. The experimental results show that both friction and wear of artificial joints fluctuate with the concentration level of biological components. Moreover, the performance also varies between material combinations. Wear debris sizes and shapes produced by ceramic and polyethylene were diverse. We conclude that the biological components of synovial fluid and their concentrations should be considered in order to select an artificial hip joint to best suit that patient.

Wide-awake Anesthesia No Tourniquet Trapeziometacarpal Joint Prosthesis Implantation.

PubMed

Müller, Camillo Theo; Christen, Thierry; Heidekruger, Paul I; Lamouille, Jessie; Raffoul, Wassim; McKee, Daniel; Lalonde, Donald H; Durand, Sébastien

2018-04-01

Wide awake local anesthesia no tourniquet (WALANT) hand surgery is a rapidly growing in popularity. WALANT has been used by hand surgeons when operating on bones, tendons, ligaments, nerve entrapments. We offer a case report of the first case in the literature describing WALANT technique when performing trapeziometacarpal joint arthroplasty with prosthesis implantation. We offer technical points on how to perform this procedure and the advantages that are associated with using WALANT for prosthesis arthroplasty.

Long-term results of the use of silicone sheets after diskectomy in the temporomandibular joint: clinical, radiographic and histopathologic findings.

PubMed

Schliephake, H; Schmelzeisen, R; Maschek, H; Haese, M

1999-10-01

The aim of the present study was to evaluate the long-term results of a group of patients who had the disk of the temporomandibular joint (TMJ) removed and permanently replaced by a silicone sheet. The study group comprised 48 patients, treated in the period from 1983 to 1993. In eight patients, the implants had to be removed after an average interval of 5.6 years and they were submitted for histopathological examination. Twenty-five of the 40 patients with silastic implants in place, and five of the 8 patients who had their implants removed, were available for long-term follow-up (mean interval of 7.0 years, SD 2.8 years). Clinical function was rated according to the Helkimo Dysfunction Index and compared to the preoperative findings. Results showed decreased tenderness of muscles and joints to palpation and increased mouth opening, but no statistically significant improvement in joint function. In 4 patients, a decrease in condylar width was found, while another 4 patients presented with thickening of the condyle by appositional bone formation. Histopathology of the failed implants showed scattered fragments of silastic material and dacron fibers with accumulation of histiocytes in immediate contact with the silicone particles and phagocytozed intracellular material. T-lymphocytes were also present in the vicinity of the silicone particles.

Surface properties of thermally treated composite wood panels

NASA Astrophysics Data System (ADS)

Croitoru, Catalin; Spirchez, Cosmin; Lunguleasa, Aurel; Cristea, Daniel; Roata, Ionut Claudiu; Pop, Mihai Alin; Bedo, Tibor; Stanciu, Elena Manuela; Pascu, Alexandru

2018-04-01

Composite finger-jointed spruce and oak wood panels have been thermally treated under standard pressure and oxygen content conditions at two different temperatures, 180 °C and respectively 200 °C for short time periods (3 and 5 h). Due to the thermally-aided chemical restructuration of the wood components, a decrease in water uptake and volumetric swelling values with up to 45% for spruce and 35% for oak have been registered, comparing to the reference samples. In relation to water resistance, a 15% increase of the dispersive component of the surface energy has been registered for the thermal-treated spruce panels, which impedes water spreading on the surface. The thermal-treated wood presents superior resistance to accelerated UV exposure and subsequently, with up to 10% higher Brinell hardness values than reference wood. The proposed thermal treatment improves the durability of the finger-jointed wood through a more economically and environmental friendly method than traditional impregnation, with minimal degradative impact on the structural components of wood.

The Influence of Artificial Cervical Disc Prosthesis Height on the Cervical Biomechanics: A Finite Element Study.

PubMed

Yuan, Wei; Zhang, Haiping; Zhou, Xiaoshu; Wu, Weidong; Zhu, Yue

2018-05-01

Artificial cervical disc replacement is expected to maintain normal cervical biomechanics. At present, the effect of the Prestige LP prosthesis height on cervical biomechanics has not been thoroughly studied. This finite element study of the cervical biomechanics aims to predict how the parameters, like range of motion (ROM), adjacent intradiscal pressure, facet joint force, and bone-implant interface stress, are affected by different heights of Prestige LP prostheses. The finite element model of intact cervical spine (C3-C7) was obtained from our previous study, and the model was altered to implant Prestige LP prostheses at the C5-C6 level. The effects of the height of 5, 6, and 7 mm prosthesis replacement on ROM, adjacent intradiscal pressure, facet joint force, as well as the distribution of bone-implant interface stress were examined. ROM, adjacent intradiscal pressure, and facet joint force increased with the prosthesis height, whereas ROM and facet joint force decreased at C5-C6. The maximal stress on the inferior surface of the prostheses was greater than that on the superior surface, and the stresses increased with the prosthesis height. The biomechanical changes were slightly affected by the height of 5 and 6 mm prostheses, but were strongly affected by the 7-mm prosthesis. An appropriate height of the Prestige LP prosthesis can preserve normal ROM, adjacent intradiscal pressure, and facet joint force. Prostheses with a height of ≥2 mm than normal can lead to marked changes in the cervical biomechanics and bone-implant interface stress. Copyright © 2018 Elsevier Inc. All rights reserved.

Surface Modifications for Improved Wear Performance in Artificial Joints: A Review

NASA Astrophysics Data System (ADS)

Sullivan, Stacey J. L.; Topoleski, L. D. Timmie

2015-11-01

Artificial joint replacement is one of the most successful treatments for arthritis. Excellent wear and corrosion resistance, together with high strength and fracture toughness, are fundamental requirements for implant materials. Wear and/or corrosion of the materials used in artificial joints may lead to implant failure. Therefore, hard and wear-resistant materials, like cobalt-chromium-molybdenum and ceramic, are currently used as bearing surfaces. However, even using such hard materials, wear and/or corrosion related failure of artificial joints remains a central concern. One primary goal in orthopedic biomaterials research is to create more wear-resistant surfaces. Different technologies have been used to create new surfaces, or to modify existing surfaces, to prevent wear. It is the intent of this overview first to provide a summary of materials currently used as bearing surfaces in artificial joints, their functions, and their contributions to device longevity. Then, we will discuss advancements in modifying those bearing surfaces to produce more wear-resistant artificial joints.

A Compliant Four-bar Linkage Mechanism that Makes the Fingers of a Prosthetic Hand More Impact Resistant

PubMed Central

Choi, Kyung Yun; Akhtar, Aadeel; Bretl, Timothy

2017-01-01

Repeated mechanical failure due to accidental impact is one of the main reasons why people with upper-limb amputations abandon commercially-available prosthetic hands. To address this problem, we present the design and evaluation of a compliant four-bar linkage mechanism that makes the fingers of a prosthetic hand more impact resistant. Our design replaces both the rigid input and coupler links with a monolithic compliant bone, and replaces the follower link with three layers of pre-stressed spring steel. This design behaves like a conventional four-bar linkage but adds lateral compliance and eliminates a pin joint, which is a main site of failure on impact. Results from free-end and fixed-end impact tests show that, compared to those made with a conventional four-bar linkage, fingers made with our design absorb up to 11% more energy on impact with no mechanical failure. We also show the integration of these fingers in a prosthetic hand that is low-cost, light-weight, and easy to assemble, and that has grasping performance comparable to commercially-available hands. PMID:29527386

Safety and 6-month effectiveness of minimally invasive sacroiliac joint fusion: a prospective study

PubMed Central

Duhon, Bradley S; Cher, Daniel J; Wine, Kathryn D; Lockstadt, Harry; Kovalsky, Don; Soo, Cheng-Lun

2013-01-01

Background Sacroiliac (SI) joint pain is an often overlooked cause of low back pain. SI joint arthrodesis has been reported to relieve pain and improve quality of life in patients suffering from degeneration or disruption of the SI joint who have failed non-surgical care. We report herein early results of a multicenter prospective single-arm cohort of patients with SI joint degeneration or disruption who underwent minimally invasive fusion using the iFuse Implant System®. Methods The safety cohort includes 94 subjects at 23 sites with chronic SI joint pain who met study eligibility criteria and underwent minimally invasive SI joint fusion with the iFuse Implant System® between August 2012 and September 2013. Subjects underwent structured assessments preoperatively, immediately postoperatively, and at 1, 3, and 6 months postoperatively, including SI joint and back pain visual analog scale (VAS), Oswestry Disability Index (ODI), Short Form-36 (SF-36), and EuroQoL-5D (EQ-5D). Patient satisfaction with surgery was assessed at 6 months. The effectiveness cohort includes the 32 subjects who have had 6-month follow-up to date. Results Mean subject age was 51 years (n=94, safety cohort) and 66% of patients were women. Subjects were highly debilitated at baseline (mean VAS pain score 78, mean ODI score 54). Three implants were used in 80% of patients; two patients underwent staged bilateral implants. Twenty-three adverse events occurred within 1 month of surgery and 29 additional events occurred between 30 days and latest follow-up. Six adverse events were severe but none were device-related. Complete 6-month postoperative follow-up was available in 26 subjects. In the effectiveness cohort, mean (± standard deviation) SI joint pain improved from a baseline score of 76 (±16.2) to a 6-month score of 29.3 (±23.3, an improvement of 49 points, P<0.0001), mean ODI improved from 55.3 (±10.7) to 38.9 (±18.5, an improvement of 15.8 points, P<0.0001) and SF-36 PCS improved from 30.7 (±4.3) to 37.0 (±10.7, an improvement of 6.7 points, P=0.003). Ninety percent of subjects who were ambulatory at baseline regained full ambulation by month 6; median time to full ambulation was 30 days. Satisfaction with the procedure was high at 85%. Conclusion Minimally invasive SI joint fusion using the iFuse Implant System® is safe. Mid-term follow-up indicates a high rate of improvement in pain and function with high rates of patient satisfaction. PMID:24363562

A practical guide for performing arthrography under fluoroscopic or ultrasound guidance.

PubMed

Lungu, Eugen; Moser, Thomas P

2015-12-01

We propose a practical approach for performing arthrography with fluoroscopic or ultrasound guidance. Different approaches to the principal joints of the upper limb (shoulder, elbow, wrist and fingers), lower limb (hip, knee, ankle and foot) as well as the facet joints of the spine are discussed and illustrated with numerous drawings. Whenever possible, we emphasise the concept of targeting articular recesses, which offers many advantages over traditional techniques aiming at the joint space. • Arthrography remains a foremost technique in musculoskeletal radiology • Most joints can be successfully accessed by targeting the articular recess • Targeting the recess offers several advantages over traditional approaches • Ultrasound-guidance is now favoured over fluoroscopy and targeting the recess is equally applicable.

Detection of rheumatoid arthritis by evaluation of normalized variances of fluorescence time correlation functions

NASA Astrophysics Data System (ADS)

Dziekan, Thomas; Weissbach, Carmen; Voigt, Jan; Ebert, Bernd; MacDonald, Rainer; Bahner, Malte L.; Mahler, Marianne; Schirner, Michael; Berliner, Michael; Berliner, Birgitt; Osel, Jens; Osel, Ilka

2011-07-01

Fluorescence imaging using the dye indocyanine green as a contrast agent was investigated in a prospective clinical study for the detection of rheumatoid arthritis. Normalized variances of correlated time series of fluorescence intensities describing the bolus kinetics of the contrast agent in certain regions of interest were analyzed to differentiate healthy from inflamed finger joints. These values are determined using a robust, parameter-free algorithm. We found that the normalized variance of correlation functions improves the differentiation between healthy joints of volunteers and joints with rheumatoid arthritis of patients by about 10% compared to, e.g., ratios of areas under the curves of raw data.

[10 congenital trigger fingers. Apropos of a case report].

PubMed

Moutet, F; Lebrun, C; Sartorius, C

1987-01-01

Ten congenital triggers fingers have been treated on a 3 years old girl after correction of congenital bilateral club feet. Such a case, without any other congenital malformation seems to be unique in the French literature and only found twice in the English one. This child in spite of a normal growth and good psychomotor development, presents an unusual face, with a mouth a little bit too small, but her karyotype is normal. No trismus and no microstomia were found to enable this case to be classified in a specific syndrome. The right diagnosis may be a non evolutive arthrogryposis of the extremities. Dividing the ten proximal pulleys (A1) let 10 voluminous nodules pass through and allowed full range of motion in nine out of ten fingers. A remaining flexion deformity of the proximal interphalangeal joint needed an anterior arthrolysis, the final result was good.

A New Clinical Sign of Lumbrical Plus Finger.

PubMed

Schuind, Frédéric A; Moungondo, Fabian; Van Wetter, Pierre

2018-06-01

Paradoxical finger extension is the classical clinical presentation of the lumbrical plus syndrome. We report a new additional sign, increased metacarpophalangeal flexion of the involved finger when the patient tries to make a fist. Three cases of lumbrical tightness are discussed, illustrating this new sign in 3 different clinical settings. The new sign was present in all 3 cases. Lumbrical tenotomy corrected the paradoxical interphalangeal extension and partly the increased metacarpophalangeal flexion. The lumbrical tendon has a relatively high moment arm relative to the metacarpophalangeal joint, which could explain the basis of this clinical sign. This new physical examination sign may help in diagnosing the lumbrical plus syndrome, a subtle complication of flexor digitorum profundus lesions that is not easily diagnosed but which is easily addressed. Copyright © 2018 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Clinical Assessment and Diagnostics of Patients With Hand Disorders: A Case Study Approach.

PubMed

Leow, Mabel Qi He; Lim, Rebecca Qian Ru; Tay, Shian Chao

Clinical assessment of the hand is important for diagnosing underlying hand disorders. Using a case study approach, the clinical assessment for three disorders of the hands is presented: trigger finger (stenosing tenosynovitis), carpal tunnel syndrome, and ulnar-sided wrist injury (styloid impingement). We assess the annular one pulley and finger range of motion for patients with trigger finger. To diagnose for carpal tunnel syndrome, assessment for Tinel's sign, Phalen's sign, abductor pollicis brevis muscle bulk, two-point discrimination, and obtaining a nerve conduction study are performed. Assessment for ulnar-sided wrist injury includes wrist range of motion, assessment of distal radial ulnar joint stability, provocation tests, grip strength, x-ray, and magnetic resonance imaging. This article begins with a description of the hand and wrist anatomy. For each case study, the clinical history is described, followed by a discussion of the pathophysiology, clinical assessments, and diagnostic tests.

CNT coated thread micro-electro-mechanical system for finger proprioception sensing

NASA Astrophysics Data System (ADS)

Shafi, A. A.; Wicaksono, D. H. B.

2017-04-01

In this paper, we aim to fabricate cotton thread based sensor for proprioceptive application. Cotton threads are utilized as the structural component of flexible sensors. The thread is coated with multi-walled carbon nanotube (MWCNT) dispersion by using facile conventional dipping-drying method. The electrical characterization of the coated thread found that the resistance per meter of the coated thread decreased with increasing the number of dipping. The CNT coated thread sensor works based on piezoresistive theory in which the resistance of the coated thread changes when force is applied. This thread sensor is sewed on glove at the index finger between middle and proximal phalanx parts and the resistance change is measured upon grasping mechanism. The thread based microelectromechanical system (MEMS) enables the flexible sensor to easily fit perfectly on the finger joint and gives reliable response as proprioceptive sensing.

Freely Chosen Index Finger Tapping Frequency Is Increased in Repeated Bouts of Tapping.

PubMed

Hansen, Ernst Albin; Ebbesen, Brian Duborg; Dalsgaard, Ane; Mora-Jensen, Mark Holten; Rasmussen, Jakob

2015-01-01

Healthy individuals (n = 40) performed index finger tapping at freely chosen frequency during repeated bouts and before and after near-maximal muscle action consisting of 3 intense flexions of the index finger metacarpal phalangeal joint. One experiment showed, unexpectedly, that a bout of tapping increased the tapping frequency in the subsequent bout. Thus, a cumulating increase of 8.2 ± 5.4% (p < .001) occurred across 4 bouts, which were all separated by 10 min rest periods. Follow-up experiments revealed that tapping frequency was still increased in consecutive bouts when rest periods were extended to 20 min. Besides, near-maximal muscle activation, followed by 5 min rest, did not affect the tapping frequency. In conclusion, freely chosen tapping frequency was increased in repeated bouts of tapping, which were separated by 10-20 min rest periods. The observed phenomenon is suggested to be termed repeated bout rate enhancement.

Two case reports-Use of relative motion orthoses to manage extensor tendon zones III and IV and sagittal band injuries in adjacent fingers.

PubMed

Hirth, Melissa J; Howell, Julianne W; O'Brien, Lisa

Case report. Injuries to adjacent fingers with differing extensor tendon (ET) zones and/or sagittal band pose a challenge to therapists as no treatment guidelines exist. This report highlights how the relative motion flexion/extension (RMF/RME) concepts were combined into one orthosis to manage a zone IV ET repair (RME) and a zone III central slip repair (RMF) in adjacent fingers (Case 1); and how a single RME orthosis was adapted to limit proximal interphalangeal joint motion to manage multi-level ET zone III-IV injuries and a sagittal band repair in adjacent fingers (case 2). Adapted relative motion orthoses allowed early active motion and graded exercises based on clinical reasoning and evidence. Outcomes were standard TAM% and Miller's criteria. 'Excellent' and 'good' outcomes were achieved by twelve weeks post surgery. Both cases returned to unrestricted work at 6 and 7 weeks. Neither reported functional deficits at discharge. Outcomes in 2 cases involving multiple digit injuries exceeded those previously reported for ET zone III-IV repairs. Relative motion orthoses can be adapted and applied to multi-finger injuries, eliminating the need for multiple, bulky or functionally-limiting orthoses. 4. Copyright © 2017 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.

A feasibility study of hand kinematics for EVA analysis using magnetic resonance imaging

NASA Technical Reports Server (NTRS)

Dickenson, Reuben D.; Lorenz, Christine H.; Peterson, Steven W.; Strauss, Alvin M.; Main, John A.

1992-01-01

A new method for analyzing the kinematics of joint motion using magnetic resonance imaging (MRI) is described. The reconstruction of the metacarpalphalangeal joint of the left index finger into a 3D graphic display is shown. From the reconstructed volumetric images, measurements of the angles of movement of the applicable bones are obtained and processed by analyzing the screw motion of the joint. Landmark positions are chosen at distinctive locations of the joint at fixed image threshold intensity levels to ensure repeatability. The primarily 2D planar motion of this joint is then studied using a method of constructing coordinate systems using three or more points. A transformation matrix based on a world coordinate system describes the location and orientation of the local target coordinate system. The findings show the applicability of MRI to joint kinematics for gaining further knowledge of the hand-glove design for EVA.

A personalized 3D-printed prosthetic joint replacement for the human temporomandibular joint: From implant design to implantation.

PubMed

Ackland, David C; Robinson, Dale; Redhead, Michael; Lee, Peter Vee Sin; Moskaljuk, Adrian; Dimitroulis, George

2017-05-01

Personalized prosthetic joint replacements have important applications in cases of complex bone and joint conditions where the shape and size of off-the-shelf components may not be adequate. The objective of this study was to design, test and fabricate a personalized 3D-printed prosthesis for a patient requiring total joint replacement surgery of the temporomandibular joint (TMJ). The new 'Melbourne' prosthetic TMJ design featured a condylar component sized specifically to the patient and fixation screw positions that avoid potential intra-operative damage to the mandibular nerve. The Melbourne prosthetic TMJ was developed for a 58-year-old female recipient with end-stage osteoarthritis of the TMJ. The load response of the prosthesis during chewing and a maximum-force bite was quantified using a personalized musculoskeletal model of the patient's masticatory system developed using medical images. The simulations were then repeated after implantation of the Biomet Microfixation prosthetic TMJ, an established stock device. The maximum condylar stresses, screw stress and mandibular stress at the screw-bone interface were lower in the Melbourne prosthetic TMJ (259.6MPa, 312.9MPa and 198.4MPa, respectively) than those in the Biomet Microfixation device (284.0MPa, 416.0MPa and 262.2MPa, respectively) during the maximum-force bite, with similar trends also observed during the chewing bite. After trialing surgical placement and evaluating prosthetic TMJ stability using cadaveric specimens, the prosthesis was fabricated using 3D printing, sterilized, and implanted into the female recipient. Six months post-operatively, the prosthesis recipient had a normal jaw opening distance (40.0 mm), with no complications identified. The new design features and immediate load response of the Melbourne prosthetic TMJ suggests that it may provide improved clinical and biomechanical joint function compared to a commonly used stock device, and reduce risk of intra-operative nerve damage during placement. The framework presented may be useful for designing and testing customized devices for the treatment of debilitating bone and joint conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

The effect of glenosphere diameter in reverse shoulder arthroplasty on muscle force, joint load, and range of motion.

PubMed

Langohr, G Daniel G; Giles, Joshua W; Athwal, George S; Johnson, James A

2015-06-01

Little is known about the effects of glenosphere diameter on shoulder joint loads. The purpose of this biomechanical study was to investigate the effects of glenosphere diameter on joint load, load angle, and total deltoid force required for active abduction and range of motion in internal/external rotation and abduction. A custom, instrumented reverse shoulder arthroplasty implant system capable of measuring joint load and varying glenosphere diameter (38 and 42 mm) and glenoid offset (neutral and lateral) was implanted in 6 cadaveric shoulders to provide at least 80% power for all variables. A shoulder motion simulator was used to produce active glenohumeral and scapulothoracic motion. All implant configurations were tested with active and passive motion with joint kinematics, loads, and moments recorded. At neutral and lateralized glenosphere positions, increasing diameter significantly increased joint load (+12 ± 21 N and +6 ± 9 N; P < .01) and deltoid load required for active abduction (+9 ± 22 N and +11 ± 15 N; P < .02), whereas joint load angle was unaffected (P > .8). Passive internal rotation was reduced with increased diameter at both neutral and lateralized glenosphere positions (-6° ± 6° and -12° ± 6°; P < .002); however, external rotation was not affected (P > .05). At neutral glenosphere position, increasing diameter increased the maximum angles of both adduction (+1° ± 1°; P = .03) and abduction (+8° ± 9°; P < .05). Lateralization also increased abduction range of motion compared with neutral (P < .01). Although increasing glenosphere diameter significantly increased joint load and deltoid force, the clinical impact of these changes is presently unclear. Internal rotation, however, was reduced, which contradicts previous bone modeling studies, which we postulate is due to increased posterior capsular tension as it is forced to wrap around a larger 42 mm implant assembly. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Antibacterial Surface Treatment for Orthopaedic Implants

PubMed Central

Gallo, Jiri; Holinka, Martin; Moucha, Calin S.

2014-01-01

It is expected that the projected increased usage of implantable devices in medicine will result in a natural rise in the number of infections related to these cases. Some patients are unable to autonomously prevent formation of biofilm on implant surfaces. Suppression of the local peri-implant immune response is an important contributory factor. Substantial avascular scar tissue encountered during revision joint replacement surgery places these cases at an especially high risk of periprosthetic joint infection. A critical pathogenic event in the process of biofilm formation is bacterial adhesion. Prevention of biomaterial-associated infections should be concurrently focused on at least two targets: inhibition of biofilm formation and minimizing local immune response suppression. Current knowledge of antimicrobial surface treatments suitable for prevention of prosthetic joint infection is reviewed. Several surface treatment modalities have been proposed. Minimizing bacterial adhesion, biofilm formation inhibition, and bactericidal approaches are discussed. The ultimate anti-infective surface should be “smart” and responsive to even the lowest bacterial load. While research in this field is promising, there appears to be a great discrepancy between proposed and clinically implemented strategies, and there is urgent need for translational science focusing on this topic. PMID:25116685

Circuit For Control Of Electromechanical Prosthetic Hand

NASA Technical Reports Server (NTRS)

Bozeman, Richard J., Jr.

1995-01-01

Proposed circuit for control of electromechanical prosthetic hand derives electrical control signals from shoulder movements. Updated, electronic version of prosthesis, that includes two hooklike fingers actuated via cables from shoulder harness. Circuit built around favored shoulder harness, provides more dexterous movement, without incurring complexity of computer-controlled "bionic" or hydraulically actuated devices. Additional harness and potentiometer connected to similar control circuit mounted on other shoulder. Used to control stepping motor rotating hand about prosthetic wrist to one of number of angles consistent with number of digital outputs. Finger-control signals developed by circuit connected to first shoulder harness transmitted to prosthetic hand via sliprings at prosthetic wrist joint.

System description document for the Anthrobot-2: A dexterous robot hand

NASA Technical Reports Server (NTRS)

Ali, Michael S.; Engler, Charles, Jr.

1991-01-01

The Anthrobot-2 is an anatomically correct, fully functioning robot hand. The number of fingers, the proportions of the links, the placement and motion of the thumb, and the shape of the palm follow those of the human hand. Each of the finger and thumb joints are servo-controlled. The Anthrobot-2 also includes a two-degree-of-freedom wrist. The entire package, including wrist, hand, and actuators, will mount on the ends of a variety of industrial manipulators. A patent has been applied for on the design. The Anthrobot-2 will be useful in tasks where dexterous manipulation or telemanipulation are required.

Pollicisation: The Myth about Creating a Pseudo-Trapezium.

PubMed

Mennen, Ulrich

2018-06-01

We have performed 14 pollicisations without creating a "pseudo-trapezium" from the metacarpal head. The entire metacarpal of the intended finger to be pollicised is removed and the proximal phalanx of the finger is inserted into the space left by the base of the excised metacarpal. The results are good to excellent in all 14 cases followed for 2-9 years. The advantages are that the operation is much simpler, thus also much quicker. The new thumb looks more like a thumb (not too long) and is more stable (ball-and-socket joint), with no long term complications often seen with the pseudo-trapezium.

Prosthetic knee design by simulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hollerbach, K; Hollister, A

1999-07-30

Although 150,000 total knee replacement surgeries are performed annually in North America, current designs of knee prostheses have mechanical problems that include a limited range of motion, abnormal gait patterns, patellofemoral joint dysfunction, implant loosening or subsidence, and excessive wear. These problems fall into three categories: failure to reproduce normal joint kinematics, which results in altered limb function; bone-implant interface failure; and material failure. Modern computer technology can be used to design, prototype, and test new total knee implants. The design team uses the full range of CAD-CAM to design and produce implant prototypes for mechanical and clinical testing. Closermore » approximation of natural knee kinematics and kinetics is essential for improved patient function and diminished implant loads. Current knee replacement designs are based on 19th Century theories that the knee moves about a variable axis of rotation. Recent research has shown, however, that knee motion occurs about two fixed, offset axes of rotation. These aces are not perpendicular to the long axes of the bones or to each other, and the axes do not intersect. Bearing surfaces of mechanisms that move about axes of rotation are surfaces of revolution of those axes which advanced CAD technology can produce. Solids with surfaces of revolution for the two axes of rotation for the knee have been made using an HP9000 workstation and Structural Ideas Master Series CAD software at ArthroMotion. The implant's CAD model should closely replicate movements of the normal knee. The knee model will have a range of flexion-extension (FE) from -5 to 120 degrees. Movements include varus, valgus, internal and external rotation, as well as flexion and extension. The patellofemoral joint is aligned perpendicular to the FE axis and replicates the natural joint more closely than those of existing prostheses. The bearing surfaces will be more congruent than current designs and should generate lower stresses in the materials.« less

Ion Beam Processing.

DTIC Science & Technology

1987-03-13

guides Taps for plastics Orthopedic implants (hip and knee joints, etc.) Extrusion spinnerettes Finishing rolls for copper rod Extrusion nozzles...detail in following sections. C. Comparison to Coating Techniques -,* Because ion implantation is a process that modifies surface properties it is often...Therefore, it is important to understand the differences between ion implantation and coating techniques, especially ion plating. The result of ion

First metatarsophalangeal joint replacement with modular three-component press-fit implant. Preliminary report.

PubMed

Kolodziej, L; Bohatyrewicz, A; Zietek, P

2013-01-01

The aim of this retrospective study was to assess functional and radiographic results of the first metatarsophalangeal joint replacement with use of unconstrained, modular, three components, porous titanium and hydroxyapatite coated, press-fit METIS® prosthesis. According to author's knowledge, results of that type of prosthesis have never been published before. 25 prosthesis were implanted in 24 patients between February 2009 and May 2011. American Orthopaedic Foot and Ankle Society Hallux Metatarsophalangeal Interphalangeal scoring system (AOFAS-HMI) was used to assess functional results. Patients were also asked if they would undergo procedure again or recommend it to other people. Weight bearing radiographs ware made at final follow up and analyzed for presence of osteolysis and radiolucencies. In 8 patients total joint replacement was introduced as a salvage after failure of previous surgery like Keller resection arthroplasty, failed arthrodesis, avascular necrosis and postoperative arthritis. In 11 patients the reason for prosthetic replacement were hallux rigidus, in 4 cases rheumatoid arthritis and gout in one patient. In two patients additional procedures like Akin phalangeal osteotomy and in one case fifth metatarsal osteotomy, was performed. There were 20 females and 4 males in presented group. The mean age at the operation was 56 years. The average follow up period was 18 months (from 12 to 36 months). The median postoperative value of AOFAS-HMI scores was 88 points (from 75 to 95 points). First metatarsophalangeal joint motion (dorsiflexion plus plantarflexion) was classified according to AOFAS-HMI ranges as: moderately restricted (between 30 to 70 degrees) in 19 patients 80% (20 prosthesis) and severely restricted (less then 30 degrees) in 5 patients (20%). 15 (64%) patients were completely satisfied, 5 (20%) reported moderate satisfaction and (16%) 4 were totally disappointed and would not undergo this procedure again. A limited hallux dorsiflexion was the main dissatisfaction reason. Partial radiolucent line was seen in one patient (4%). Authors noticed two serious complications. In one patient, with rheumatoid arthritis, deep infection occurred 12 months after prosthesis implantation. In second case phalangeal implant was revised due to misalignment. METIS® metatarsophalangeal joint replacement allows alleviate of pain relating to hallux rigidus and partial restoration of joint movement, even in patients after failures of primary metatarsophalangeal joint surgery. AOFAS-HMI results are better than previously reported in the literature in assessment of the first metatarsophalangeal joint replacement. Radiographic results imply satisfactory bone ingrowth into the cementless implants.

Kirschner-wire fixation for postburn flexion contracture deformity and consequences on articular surface.

PubMed

Sungur, Nezih; Ulusoy, Mustafa Gürhan; Boyacgil, Süreyya; Ortaparmak, Hülya; Akyüz, Mihriban; Ortak, Turgut; Koçer, Uğur; Sensöz, Omer

2006-02-01

Kirschner-wire (K-wire) fixation for 3-6 weeks is an approved method for stabilization of the fingers after the release of flexion contracture deformity. On the other hand, articular surface damage in small joints due to pin fixation is still a topic of debate. Reports claiming permanent joint destruction due to this procedure exist in the literature. To clarify this doubt, a prospective study was carried out in 72 patients with flexion contracture of the hand fingers. After the surgical release of the deformity, immobilization of the interphalangeal (IP) and metacarpophalangeal (MCP) joints was carried out with K-wire fixation for 3 weeks. Clinical evaluation of the patients was accomplished with total active motion (TAM), grip, and pinch force measurements, whereas magnetic resonance (MR) and radionuclide imaging were used as radiodiagnostic tools. Mean follow-up period of the patients was 32 months. Satisfactory results were obtained in terms of functional and esthetic aspects. Evaluation of the data derived from the clinical and radiologic measurements revealed no permanent articular surface damage. K-wire fixation was documented to be an invaluable therapeutic approach not only to prevent recurrence of the contracture deformity but also to stabilize the skin graft effectively. This technique was concluded to provide effective immobilization without permanent articular damage.

Analysis of the reliability and reproducibility of goniometry compared to hand photogrammetry

PubMed Central

de Carvalho, Rosana Martins Ferreira; Mazzer, Nilton; Barbieri, Claudio Henrique

2012-01-01

Objective: To evaluate the intra- and inter-examiner reliability and reproducibility of goniometry in relation to photogrammetry of hand, comparing the angles of thumb abduction, PIP joint flexion of the II finger and MCP joint flexion of the V finger. Methods: The study included 30 volunteers, who were divided into three groups: one group of 10 physiotherapy students, one group of 10 physiotherapists, and a third group of 10 therapists of the hand. Each examiner performed the measurements on the same hand mold, using the goniometer followed by two photogrammetry software programs; CorelDraw® and ALCimagem®. Results: The results revealed that the groups and the methods proposed presented inter-examiner reliability, generally rated as excellent (ICC 0.998 I.C. 95% 0.995 - 0.999). In the intra-examiner evaluation, an excellent level of reliability was found between the three groups. In the comparison between groups for each angle and each method, no significant differences were found between the groups for most of the measurements. Conclusion: Goniometry and photogrammetry are reliable and reproducible methods for evaluating measurements of the hand. However, due to the lack of similar references, detailed studies are needed to define the normal parameters between the methods in the joints of the hand. Level of Evidence II, Diagnostic Study. PMID:24453594

[Initial studies of the application of the linear signal transfer theory in evaluating diaphanoscopic examinations exemplified by rheumatism diagnosis].

PubMed

Beuthan, J; Cappius, H J; Hielscher, A; Hopf, M; Klose, A; Netz, U

2001-11-01

Rheumatoid arthritis affecting the small joints--in particular the fingers--has advantageous geometry for the transmission of near-infrared (NIR) light. Examination of the optical properties of tissues has revealed that as a result of changes to the capsule and synovial fluid there is a considerable increase in photon scattering already in the early stages of the disease--in particular around 685 nm. This suggests the appropriateness of analysing the photon density profile resulting from punctiform irradiation of the joint. In a first approximation, the point spread function of transmitted photon density is confirmed to be proportional to a Gauss distribution, as suggested by Arridge. In accordance with the linear signal transfer theory, therefore, it is possible to establish a virtual transfer system described by a first-order differential equation. (The tissue optical conditions mu a < mu's and mu a = constant (mu a = absorption coefficient) were assumed). The parameter mu's (= reduced scattering coefficient) was determined by linear approximation of the Gauss distribution to the calculated or measured point spread function. For selected patient data, the mu's was determined in healthy and diseased finger joints (e.g. 10.1 cm-1 and 26.8 cm-1, respectively), and the results were in good agreement with those obtained experimentally.

Osteogenic Activity of Locally Applied Small Molecule Drugs in a Rat Femur Defect Model

PubMed Central

Cottrell, Jessica A.; Vales, Francis M.; Schachter, Deborah; Wadsworth, Scott; Gundlapalli, Rama; Kapadia, Rasesh; O'Connor, J. Patrick

2010-01-01

The long-term success of arthroplastic joints is dependent on the stabilization of the implant within the skeletal site. Movement of the arthroplastic implant within the bone can stimulate osteolysis, and therefore methods which promote rigid fixation or bone growth are expected to enhance implant stability and the long-term success of joint arthroplasty. In the present study, we used a simple bilateral bone defect model to analyze the osteogenic activity of three small-molecule drug implants via microcomputerized tomography (micro-CT) and histomorphometry. In this study, we show that local delivery of alendronate, but not lovastatin or omeprazole, led to significant new bone formation at the defect site. Since alendronate impedes osteoclast-development, it is theorized that alendronate treatment results in a net increase in bone formation by preventing osteoclast mediated remodeling of the newly formed bone and upregulating osteoblasts. PMID:20625499

Joint positions matter for ultrasound examination of RA patients-increased power Doppler signal in neutral versus flat position of hands.

PubMed

Husic, Rusmir; Lackner, Angelika; Stradner, Martin H; Hermann, Josef; Dejaco, Christian

2017-08-01

Position of joints might influence the result of US examination in patients with RA. The purpose of this work was to compare grey-scale (GS) and power Doppler (PWD) findings obtained in neutral vs flat position of hands. A cross-sectional study of 42 RA patients with active disease. Two dimensional and 3D sonography of wrists and MCP joints were conducted in two different joint positions: neutral position, which is a slight flexion of the fingers with relaxed extensor muscles; and flat position, where all palm and volar sides of fingers touch the Table. Two dimensional GS synovitis (GSS) and PWD signals were scored semi-quantitatively (0-3). For 3D sonography, the percentage of PWD voxels within a region of interest was calculated. GSS was not quantified using 3D sonography. Compared with neutral position, 2D PWD signals disappeared in 28.3% of joints upon flattening. The median global 2D PWD score (sum of all PWD scores of an individual patient) decreased from 8 to 3 ( P < 0.001), and the global 3D PWD voxel score from 3.8 to 0.9 ( P < 0.001). The reduction of PWD scores was similar in all joints (2D: minus 50%, 3D: minus 66.4-80.1%). Inter- and intrareader agreement of PWD results was good (intraclass correlation coefficient: 0.75-0.82). In RA, a neutral position of the hands is linked to a higher sensitivity of 2D and 3D sonography in detecting PWD signals at wrists and MCP joints, compared with a flat position. Standardization of the scanning procedure is essential for obtaining comparable US results in RA patients in trials and clinical routines. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Bone Repair and Military Readiness

DTIC Science & Technology

2012-10-25

formation. Orthopedic surgeons have had to adapt surgical techniques to account for issues with cementing total joint prostheses and subsequent total joint ...the silorane composite has the potential to support osseous integration around the cemented total joint implant and may generate less immunogenic wear...factors, and potential for osseointegration/osseoinduction, this material has potential to be used for screw augmentation, total hip/knee joint

Does the type of somatosensory information from the contralateral finger touch affect grip force control while lifting an object?

PubMed

Chen, Bing; Aruin, Alexander S

2013-11-27

The magnitude of grip force used to lift and transport a hand-held object is decreased if a light finger touch from the contralateral arm is provided to the wrist of the target arm. We investigated whether the type of contralateral arm sensory input that became available with the finger touch to the target arm affects the way grip force is reduced. Nine healthy subjects performed the same task of lifting and transporting an instrumented object with no involvement of the contralateral arm and when an index finger touch of the contralateral arm was provided to the wrist, elbow, and shoulder. Touching the wrist and elbow involved movements of the contralateral arm; no movements were produced while touching the shoulder. Grip force was reduced by approximately the same amount in all conditions with the finger touch compared to the no touch condition. This suggests that information from the muscle and joint receptors of the contralateral arm is used in control of grip force when a finger touch is provided to the wrist and elbow, and cutaneous information is utilized when lifting an object while touching the shoulder. The results of the study provide additional evidence to support the use of a second arm in the performance of activities of daily living and stress the importance of future studies investigating contralateral arm sensory input in grip force control. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

[Minimally invasive approaches to hip and knee joints for total joint replacement].

PubMed

Rittmeister, M; König, D P; Eysel, P; Kerschbaumer, F

2004-11-01

The manuscript features the different minimally invasive approaches to the hip for joint replacement. These include medial, anterior, anterolateral, and posterior approaches. The concept of minimally invasive hip arthroplasty makes sense if it is an integral part of a larger concept to lower postoperative morbidity. Besides minimal soft tissue trauma, this concept involves preoperative patient education, preemptive analgesia, and postoperative physiotherapy. It is our belief that minimal incision techniques for the hip are not suited for all patients and all surgeons. The different minimally invasive approaches to the knee joint for implantation of a knee arthroplasty are described and discussed. There have been no studies published yet that fulfill EBM criteria. The data so far show that minimally invasive approaches and implantation techniques for total knee replacements lead to quicker rehabilitation of patients.

Overcoming boundaries of worldwide joint arthroplasty registers: the European Arthroplasty Register minimal dataset.

PubMed

Sadoghi, Patrick; Leithner, Andreas; Labek, Gerold

2013-09-01

Worldwide joint arthroplasty registers are instrumental to screen for complications or implant failures. In order to achieve comparable results a similar classification dataset is essential. The authors therefore present the European Federation of National Associations of Orthopaedics and Traumatology (EFORT) European Arthroplasty Register (EAR) minimal dataset for primary and revision joint arthroplasty. Main parameters include the following: date of operation, country, hospital ID-code, patient's name and prename, birthday, identification code of the implant, gender, diagnosis, preoperations, type of prosthesis (partial, total), side, cementation technique, use of antibiotics in the cement, surgical approach, and others specifically related to the affected joint. The authors believe that using this minimal dataset will improve the chance for a worldwide comparison of arthroplasty registers and ask future countries for implementation. Copyright © 2013 Elsevier Inc. All rights reserved.

Joint immobilization inhibits spontaneous hyaline cartilage regeneration induced by a novel double-network gel implantation.

PubMed

Arakaki, Kazunobu; Kitamura, Nobuto; Kurokawa, Takayuki; Onodera, Shin; Kanaya, Fuminori; Gong, Jian-Ping; Yasuda, Kazunori

2011-02-01

We have recently discovered that spontaneous hyaline cartilage regeneration can be induced in an osteochondral defect in the rabbit, when we implant a novel double-network (DN) gel plug at the bottom of the defect. To clarify whether joint immobilization inhibits the spontaneous hyaline cartilage regeneration, we conducted this study with 20 rabbits. At 4 or 12 weeks after surgery, the defect in the mobile knees was filled with a sufficient volume of the hyaline cartilage tissue rich in proteoglycan and type-2 collagen, while no cartilage tissues were observed in the defect in the immobilized knees. Type-2 collagen, Aggrecan, and SOX9 mRNAs were expressed only in the mobile knees at each period. This study demonstrated that joint immobilization significantly inhibits the spontaneous hyaline cartilage regeneration induced by the DN gel implantation. This fact suggested that the mechanical environment is one of the significant factors to induce this phenomenon.

In vivo measured joint friction in hip implants during walking after a short rest.

PubMed

Damm, Philipp; Bender, Alwina; Duda, Georg; Bergmann, Georg

2017-01-01

It has been suspected that friction in hip implants is higher when walking is initiated after a resting period than during continuous movement. It cannot be excluded that such increased initial moments endanger the cup fixation in the acetabulum, overstress the taper connections in the implant or increase wear. To assess these risks, the contact forces, friction moments and friction coefficients in the joint were measured in vivo in ten subjects. Instrumented hip joint implants with telemetric data transmission were used to access the contact loads between the cup and head during the first steps of walking after a short rest. The analysis demonstrated that the contact force is not increased during the first step. The friction moment in the joint, however, is much higher during the first step than during continuous walking. The moment increases throughout the gait cycle were 32% to 143% on average and up to 621% individually. The high initial moments will probably not increase wear by much in the joint. However, comparisons with literature data on the fixation resistance of the cup against moments made clear that the stability can be endangered. This risk is highest during the first postoperative months for cementless cups with insufficient under-reaming. The high moments after a break can also put taper connections between the head and neck and neck and shaft at a higher risk. During continuous walking, the friction moments individually were extremely varied by factors of 4 to 10. Much of this difference is presumably caused by the varying lubrication properties of the synovia. These large moment variations can possibly lead to friction-induced temperature increases during walking, which are higher than the 43.1°C which have previously been observed in a group of only five subjects.

Management of pain secondary to temporomandibular joint syndrome with peripheral nerve stimulation.

PubMed

Rodriguez-Lopez, Manuel J; Fernandez-Baena, Mariano; Aldaya-Valverde, Carlos

2015-01-01

Temporomandibular joint syndrome, or Costen syndrome, is a clinically diagnosed disorder whose most common symptoms include joint pain and clicking, difficulty opening the mouth, and temporomandibular joint discomfort. The temporomandibular joint (TMJ) is supplied by the auriculotemporal nerve, a collateral branch of the mandibular nerve (the V3 branch of the trigeminal nerve). The aim of this study is to assess the effectiveness and safety of permanent peripheral nerve stimulation to relieve TMJ pain. This case series is a prospective study. Pain Unit of a regional universitary hospital. The study included 6 female patients with temporomandibular pain lasting from 2 to 8 years that did not respond to intraarticular local anesthetic and corticoid injections. After a positive diagnostic block test, the patients were implanted with quadripolar or octapolar leads in the affected preauricular region for a 2-week stimulation test phase, after which the leads were connected to a permanent implanted pulse generator. Results of the visual analog scale, SF-12 Health Survey, Brief Pain Inventory, and drug intake were recorded at baseline and at 4, 12, and 24 weeks after the permanent implant. Five out of 6 patients experienced pain relief exceeding 80% (average 72%) and received a permanent implant. The SF-12 Health Survey results were very positive for all specific questions, especially items concerning the physical component. Patients reported returning to normal physical activity and rest at night. Four patients discontinued their analgesic medication and 1 patient reduced their gabapentin dose by 50%. Sample size; impossibility of placebo control. Patients affected with TMJ syndrome who do not respond to conservative treatments may find a solution in peripheral nerve stimulation, a simple technique with a relatively low level of complications.

Intermittent Parathyroid Hormone Enhances Cancellous Osseointegration of a Novel Murine Tibial Implant.

PubMed

Yang, Xu; Ricciardi, Benjamin F; Dvorzhinskiy, Aleksey; Brial, Caroline; Lane, Zachary; Bhimani, Samrath; Burket, Jayme C; Hu, Bin; Sarkisian, Alexander M; Ross, F Patrick; van der Meulen, Marjolein C H; Bostrom, Mathias P G

2015-07-01

Long-term fixation of uncemented joint implants requires early mechanical stability and implant osseointegration. To date, osseointegration has been unreliable and remains a major challenge in cementless total knee arthroplasty. We developed a murine model in which an intra-articular proximal tibial titanium implant with a roughened stem can be loaded through the knee joint. Using this model, we tested the hypothesis that intermittent injection of parathyroid hormone (iPTH) would increase proximal tibial cancellous osseointegration. Ten-week-old female C57BL/6 mice received a subcutaneous injection of PTH (40 μg/kg/day) or a vehicle (n = 45 per treatment group) five days per week for six weeks, at which time the baseline group was killed (n = 6 per treatment group) and an implant was inserted into the proximal part of the tibiae of the remaining mice. Injections were continued until the animals were killed at one week (n = 7 per treatment group), two weeks (n = 14 per treatment group), or four weeks (n = 17 per treatment group) after implantation. Outcomes included peri-implant bone morphology as analyzed with micro-computed tomography (microCT), osseointegration percentage and bone area fraction as shown with backscattered electron microscopy, cellular composition as demonstrated by immunohistochemical analysis, and pullout strength as measured with mechanical testing. Preimplantation iPTH increased the epiphyseal bone volume fraction by 31.6%. When the data at post-implantation weeks 1, 2, and 4 were averaged for the iPTH-treated mice, the bone volume fraction was 74.5% higher in the peri-implant region and 168% higher distal to the implant compared with the bone volume fractions in the same regions in the vehicle-treated mice. Additionally, the trabecular number was 84.8% greater in the peri-implant region and 74.3% greater distal to the implant. Metaphyseal osseointegration and bone area fraction were 28.1% and 70.1% higher, respectively, in the iPTH-treated mice than in the vehicle-treated mice, and the maximum implant pullout strength was 30.9% greater. iPTH also increased osteoblast and osteoclast density by 65.2% and 47.0%, respectively, relative to the values in the vehicle group, when the data at post-implantation weeks 1 and 2 were averaged. iPTH increased osseointegration, cancellous mass, and the strength of the bone-implant interface. Our murine model is an excellent platform on which to study biological enhancement of cancellous osseointegration. Copyright © 2015 by The Journal of Bone and Joint Surgery, Incorporated.

miR-200 Regulates Endometrial Development During Early Pregnancy

PubMed Central

Mainigi, Monica A.; Word, R. Ann; Kraus, W. Lee; Mendelson, Carole R.

2016-01-01

For successful embryo implantation, endometrial stromal cells must undergo functional and morphological changes, referred to as decidualization. However, the molecular mechanisms that regulate implantation and decidualization are not well defined. Here we demonstrate that the estradiol- and progesterone-regulated microRNA (miR)-200 family was markedly down-regulated in mouse endometrial stromal cells prior to implantation, whereas zinc finger E-box binding homeobox-1 and -2 and other known and predicted targets were up-regulated. Conversely, miR-200 was up-regulated during in vitro decidualization of human endometrial stromal cells. Knockdown of miR-200 negatively affected decidualization and prevented the mesenchymal-epithelial transition-like changes that accompanied decidual differentiation. Notably, superovulation of mice and humans altered miR-200 expression. Our findings suggest that hormonal alterations that accompany superovulation may negatively impact endometrial development and decidualization by causing aberrant miR-200 expression. PMID:27533790

Optimal Irrigation and Debridement of Infected Joint Implants

PubMed Central

Schwechter, Evan M.; Folk, David; Varshney, Avanish K.; Fries, Bettina C.; Kim, Sun Jin; Hirsh, David M.

2014-01-01

Acute postoperative and acute, late hematogenous prosthetic joint infections have been treated with 1-stage irrigation and debridement with polyethylene exchange. Success rates, however, are highly variable. Reported studies demonstrate that detergents are effective at decreasing bacterial colony counts on orthopedic implants. Our hypothesis is that the combination of a detergent and an antiseptic would be more effective than using a detergent alone to decrease colony counts from a methicillin-resistant Staphylococcus aureus biofilm-coated titanium alloy disk simulating an orthopedic implant. In our study of various agents tested, chlorhexidine gluconate scrub (antiseptic and detergent) was the most effective at decreasing bacterial colony counts both prereincubation and postreincubation of the disks; pulse lavage and scrubbing were not more effective than pulse lavage alone. PMID:21641757

Triangular Titanium Implants for Minimally Invasive Sacroiliac Joint Fusion: 2-Year Follow-Up from a Prospective Multicenter Trial.

PubMed

Duhon, Bradley S; Bitan, Fabien; Lockstadt, Harry; Kovalsky, Don; Cher, Daniel; Hillen, Travis

2016-01-01

Sacroiliac joint (SIJ) dysfunction is an underdiagnosed condition. Several published cohorts have reported favorable mid-term outcomes after SIJ fusion using titanium implants placed across the SIJ. Herein we report long-term (24-month) results from a prospective multicenter clinical trial. One hundred and seventy-two subjects at 26 US sites with SI joint dysfunction were enrolled and underwent minimally invasive SI joint fusion with triangular titanium implants. Subjects underwent structured assessments preoperatively and at 1, 3, 6, 12, 18 and 24 months postoperatively, including SIJ pain ratings (0-100 visual analog scale), Oswestry Disability Index (ODI), Short Form-36 (SF-36), EuroQOL-5D (EQ-5D), and patient satisfaction. Adverse events were collected throughout follow-up. All participating patients underwent a high-resolution pelvic CT scan at 1 year. Mean subject age was 50.9 years and 69.8% were women. SIJ pain was present for an average of 5.1 years prior to surgical treatment. SIJ pain decreased from 79.8 at baseline to 30.4 at 12 months and remained low at 26.0 at 24 months (p<.0001 for change from baseline). ODI decreased from 55.2 at baseline to 31.5 at 12 months and remained low at 30.9 at 24 months (p<.0001 for change from baseline). Quality of life (SF-36 and EQ-5D) improvements seen at 12 months were sustained at 24 months. The proportion of subjects taking opioids for SIJ or low back pain decreased from 76.2% at baseline to 55.0% at 24 months (p <.0001). To date, 8 subjects (4.7%) have undergone one or more revision SIJ surgeries. 7 device-related adverse events occurred. CT scan at one year showed a high rate (97%) of bone adherence to at least 2 implants on both the iliac and sacral sides with modest rates of bone growth across the SIJ. In this study of patients with SIJ dysfunction, minimally invasive SI joint fusion using triangular titanium implants showed marked improvements in pain, disability and quality of life at 2 years. Imaging showed that bone apposition to implants was common but radiographic evidence of intraarticular fusion within the joint may take more than 1 year in many patients. This prospective multicenter clinical trial was approved by local or regional IRBs at each center prior to first patient enrollment. Informed consent with IRB-approved study-specific consent forms was obtained from all patients prior to participation.

Triangular Titanium Implants for Minimally Invasive Sacroiliac Joint Fusion: 2-Year Follow-Up from a Prospective Multicenter Trial

PubMed Central

Bitan, Fabien; Lockstadt, Harry; Kovalsky, Don; Cher, Daniel; Hillen, Travis

2016-01-01

Background Sacroiliac joint (SIJ) dysfunction is an underdiagnosed condition. Several published cohorts have reported favorable mid-term outcomes after SIJ fusion using titanium implants placed across the SIJ. Herein we report long-term (24-month) results from a prospective multicenter clinical trial. Methods One hundred and seventy-two subjects at 26 US sites with SI joint dysfunction were enrolled and underwent minimally invasive SI joint fusion with triangular titanium implants. Subjects underwent structured assessments preoperatively and at 1, 3, 6, 12, 18 and 24 months postoperatively, including SIJ pain ratings (0-100 visual analog scale), Oswestry Disability Index (ODI), Short Form-36 (SF-36), EuroQOL-5D (EQ-5D), and patient satisfaction. Adverse events were collected throughout follow-up. All participating patients underwent a high-resolution pelvic CT scan at 1 year. Results Mean subject age was 50.9 years and 69.8% were women. SIJ pain was present for an average of 5.1 years prior to surgical treatment. SIJ pain decreased from 79.8 at baseline to 30.4 at 12 months and remained low at 26.0 at 24 months (p<.0001 for change from baseline). ODI decreased from 55.2 at baseline to 31.5 at 12 months and remained low at 30.9 at 24 months (p<.0001 for change from baseline). Quality of life (SF-36 and EQ-5D) improvements seen at 12 months were sustained at 24 months. The proportion of subjects taking opioids for SIJ or low back pain decreased from 76.2% at baseline to 55.0% at 24 months (p <.0001). To date, 8 subjects (4.7%) have undergone one or more revision SIJ surgeries. 7 device-related adverse events occurred. CT scan at one year showed a high rate (97%) of bone adherence to at least 2 implants on both the iliac and sacral sides with modest rates of bone growth across the SIJ. Conclusions In this study of patients with SIJ dysfunction, minimally invasive SI joint fusion using triangular titanium implants showed marked improvements in pain, disability and quality of life at 2 years. Imaging showed that bone apposition to implants was common but radiographic evidence of intraarticular fusion within the joint may take more than 1 year in many patients. This prospective multicenter clinical trial was approved by local or regional IRBs at each center prior to first patient enrollment. Informed consent with IRB-approved study-specific consent forms was obtained from all patients prior to participation. PMID:27162715

The influence of abutment screw tightening on screw joint configuration.

PubMed

Lang, Lisa A; Wang, Rui-Feng; May, Kenneth B

2002-01-01

Limiting abutment-to-implant hexagonal discrepancies and rotational movement of the abutment around the implant to less than 5 degrees would result in a more stable screw joint. However, the exact relationship after abutment screw tightening is unknown, as is the effect of a counter-torque device in limiting abutment movement during screw tightening. This study examined the orientation of the abutment hexagon to the implant hexagon after tightening of the abutment screw for several abutment systems with and without the use of a counter-torque device. Thirty conical self-tapping implants (3.75 x 10.0 mm) and 10 wide-platform Brånemark System implants (5.0 x 10.0 mm), along with 10 abutment specimens from the CeraOne, Estheticone, Procera, and AuraAdapt systems, were selected for this investigation. The implants were placed in a holding device prior to tightening of the abutments. When the tightening torque recommended for each abutment system was reached with the use of a torque controller, each implant abutment specimen was removed from the holding device and embedded in a hard resin medium. The specimens were sectioned in a horizontal direction at the level of the hexagons and cleansed of debris prior to examination. The hexagon orientations were assessed as the degree and direction of rotation of the abutment hexagon around the implant hexagon. The range of the maximum degrees of rotation for all 4 abutment groups tightened with or without the counter-torque device was slightly more than 3.53 degrees. The absolute degrees of rotation for all 4 abutment groups were less than 1.50 degrees with or without the use of the counter-torque device. The hexagon-to-hexagon orientation measured as rotational fit on all abutment systems was below the 5 degrees suggested as optimal for screw joint stability. The absolute degrees of rotation for all 4 abutment groups were less than 1.50 degrees regardless of whether the counter-torque device was used.

Surface characteristics of bioactive Ti fabricated by chemical treatment for cartilaginous-integration.

PubMed

Miyajima, Hiroyuki; Ozer, Fusun; Imazato, Satoshi; Mante, Francis K

2017-09-01

Artificial hip joints are generally expected to fail due to wear after approximately 15years and then have to be replaced by revision surgery. If articular cartilage can be integrated onto the articular surfaces of artificial joints in the same way as osseo-integration of titanium dental implants, the wear of joint implants may be reduced or prevented. However, very few studies have focused on the relationship between Ti surface and cartilage. To explore the possibility of cartilaginous-integration, we fabricated chemically treated Ti surfaces with H 2 O 2 /HCl, collagen type II and SBF, respectively. Then, we evaluated surface characteristics of the prepared Ti samples and assessed the cartilage formation by culturing chondrocytes on the Ti samples. When oxidized Ti was immersed in SBF for 7days, apatite was formed on the Ti surface. The surface characteristics of Ti indicated that the wettability was increased by all chemical treatments compared to untreated Ti, and that H 2 O 2 /HCl treated surface had significantly higher roughness compared to the other three groups. Chondrocytes produced significantly more cartilage matrix on all chemically treated Ti surfaces compared to untreated Ti. Thus, to realize cartilaginous-integration and to prevent wear of the implants in joints, application of bioactive Ti formed by chemical treatment would be a promising and effective strategy to improve durability of joint replacement. Copyright © 2017 Elsevier B.V. All rights reserved.

Sensate Scaffolds Can Reliably Detect Joint Loading

PubMed Central

Bliss, C. L.; Szivek, J. A.; Tellis, B. C.; Margolis, D. S.; Schnepp, A. B.; Ruth, J. T.

2008-01-01

Treatment of cartilage defects is essential to the prevention of osteoarthritis. Scaffold-based cartilage tissue engineering shows promise as a viable technique to treat focal defects. Added functionality can be achieved by incorporating strain gauges into scaffolds, thereby providing a real-time diagnostic measurement of joint loading. Strain-gauged scaffolds were placed into the medial femoral condyles of 14 adult canine knees and benchtop tested. Loads between 75 and 130 N were applied to the stifle joints at 30°, 50°, and 70° of flexion. Strain-gauged scaffolds were able to reliably assess joint loading at all applied flexion angles and loads. Pressure sensitive films were used to determine joint surface pressures during loading and to assess the effect of scaffold placement on joint pressures. A comparison of peak pressures in control knees and joints with implanted scaffolds, as well as a comparison of pressures before and after scaffold placement, showed that strain-gauged scaffold implantation did not significantly alter joint pressures. Future studies could possibly use strain-gauged scaffolds to clinically establish normal joint loads and to determine loads that are damaging to both healthy and tissue-engineered cartilage. Strain-gauged scaffolds may significantly aid the development of a functional engineered cartilage tissue substitute as well as provide insight into the native environment of cartilage. PMID:16941586

Perioperative alendronate, risedronate, calcitonin and indomethacin treatment alters femoral stem fixation and periprosthetic bone mineral density in ovariectomized rats.

PubMed

Cankaya, Deniz; Tabak, Yalcin; Ozturk, Akif Muhtar; Gunay, Muhammed Cuneyd

2015-07-01

Many factors affect implant stability and periprosthetic bone mineral density (BMD) following total joint arthroplasty. We asked whether perioperative alendronate, risedronate, calcitonin and indomethacine administration altered (1) femoral stem shear strength and periprosthetic bone mineral density BMD in ovariectomized rats and (2) whether there were differences in the effect of these drugs. Thirty overiectomized rats were divided into five groups and implanted with intramedullary mini-cortical screws in the femur. Four groups were treated with alendronate, risedronate, salmon calcitonin and indomethacin for 4 weeks preoperatively and 8 weeks postoperatively. Although alendronate and risedronate increased the periprosthetic BMD more than calcitonin, they did not alter implant fixation compared to calcitonin. Indomethacin significantly decreased the BMD around the stem and implant stability compared to all other groups. This study showed that perioperative treatment with bisphosphonates and calcitonin improved the BMD around the stems and implant stability. Although bisphosphonates increased the BMD more than calcitonin, there was no difference in implant stability. Indomethacin markedly decreased the periprosthetic BMD and implant stability. The main clinical significance of our study was the finding about the need to strictly avoid long-term use of high-dose nonsteroidal antiinflammatory drugs for patients who have major joint arthritis and a previous history of arthroplasty.

Why Does Joint Attention Look Atypical in Autism?

PubMed Central

Gernsbacher, Morton Ann; Stevenson, Jennifer L.; Khandakar, Suraiya; Goldsmith, H. Hill

2014-01-01

This essay answers the question of why autistic children are less likely to initiate joint attention (e.g., use their index finger to point to indicate interest in something) and why they are less likely to respond to bids for their joint attention (e.g., turn their heads to look at something to which another person points). It reviews empirical evidence that autistic toddlers, children, adolescents, and adults can attend covertly, even to social stimuli, such as the direction in which another person’s eyes are gazing. It also reviews empirical evidence that autistics of various ages understand the intentionality of other persons’ actions. The essay suggests that autistics’ atypical resistance to distraction, atypical skill at parallel perception, and atypical execution of volitional actions underlie their atypical manifestations of joint attention. PMID:25520747

A Neuromuscular Electrical Stimulation (NMES) and robot hybrid system for multi-joint coordinated upper limb rehabilitation after stroke.

PubMed

Rong, Wei; Li, Waiming; Pang, Mankit; Hu, Junyan; Wei, Xijun; Yang, Bibo; Wai, Honwah; Zheng, Xiaoxiang; Hu, Xiaoling

2017-04-26

It is a challenge to reduce the muscular discoordination in the paretic upper limb after stroke in the traditional rehabilitation programs. In this study, a neuromuscular electrical stimulation (NMES) and robot hybrid system was developed for multi-joint coordinated upper limb physical training. The system could assist the elbow, wrist and fingers to conduct arm reaching out, hand opening/grasping and arm withdrawing by tracking an indicative moving cursor on the screen of a computer, with the support from the joint motors and electrical stimulations on target muscles, under the voluntary intention control by electromyography (EMG). Subjects with chronic stroke (n = 11) were recruited for the investigation on the assistive capability of the NMES-robot and the evaluation of the rehabilitation effectiveness through a 20-session device assisted upper limb training. In the evaluation, the movement accuracy measured by the root mean squared error (RMSE) during the tracking was significantly improved with the support from both the robot and NMES, in comparison with those without the assistance from the system (P < 0.05). The intra-joint and inter-joint muscular co-contractions measured by EMG were significantly released when the NMES was applied to the agonist muscles in the different phases of the limb motion (P < 0.05). After the physical training, significant improvements (P < 0.05) were captured by the clinical scores, i.e., Modified Ashworth Score (MAS, the elbow and the wrist), Fugl-Meyer Assessment (FMA), Action Research Arm Test (ARAT), and Wolf Motor Function Test (WMFT). The EMG-driven NMES-robotic system could improve the muscular coordination at the elbow, wrist and fingers. ClinicalTrials.gov. NCT02117089 ; date of registration: April 10, 2014.

Three-dimensional movement analysis of handwriting in subjects with mild hemiparesis.

PubMed

Harada, Takako; Okajima, Yasutomo; Takahashi, Hidetoshi

2010-08-01

To investigate the effects of hemiparesis on handwriting using a 3-dimensional movement analyzer. Comparative case study. Ambulatory care clinic. Right-handed patients (n=25; mean age +/- SD, 62.3+/-10y) with mild right hemiparesis secondary to subcortical stroke, and age-matched (n=10; 65.6+/-13y) and age-unmatched (n=15; 32.4+/-10y) control subjects. Not applicable. Time required to write a Japanese character of 2 different sizes and average speed of handwriting at the pen tip. Average radii of tracks of the moving pen tip, metacarpal head of the index finger, and distal end of the forearm during writing. Correlation coefficients of the instantaneous speed-time graph of the pen tip with that of the index finger and with that of the distal forearm during writing. Time for writing with the hemiparetic right hand was longer than that with the unaffected left hand (P=.05 approximately .03), while it was shorter in healthy control subjects (P=.07 approximately .05). In contrast with the left-hand writing, the track radius of the pen tip of the right-hand writing in patients with hemiparesis with normal joint position sense was significantly larger than that of the finger or distal forearm (P=.01). The finding was the same as in the young and elderly control subjects. This right-left difference disappeared in the patients with hemiparesis with position sense impairment. The correlation coefficient of speed between the pen tip and the finger was larger in right-hand than left-hand writing in the control and sensory-normative patients with hemiparesis even though the difference was significant only in the healthy elderly subjects (P=.03). Irrespective of the right or left hand use, the correlation coefficient between the pen tip and the finger or distal forearm significantly increased as the character size increased (P=.03 approximately 6 x10(-6)) in all subjects and patients. However, this size-related difference was less significant in the patients with sensory impairment. The characteristics of handwriting movement by the dominant hand were preserved in patients with mild dominant-hand hemiparesis when joint position sense was normative but were lost in those with position sense impairment.

Restoring motor control and sensory feedback in people with upper extremity amputations using arrays of 96 microelectrodes implanted in the median and ulnar nerves.

PubMed

Davis, T S; Wark, H A C; Hutchinson, D T; Warren, D J; O'Neill, K; Scheinblum, T; Clark, G A; Normann, R A; Greger, B

2016-06-01

An important goal of neuroprosthetic research is to establish bidirectional communication between the user and new prosthetic limbs that are capable of controlling >20 different movements. One strategy for achieving this goal is to interface the prosthetic limb directly with efferent and afferent fibres in the peripheral nervous system using an array of intrafascicular microelectrodes. This approach would provide access to a large number of independent neural pathways for controlling high degree-of-freedom prosthetic limbs, as well as evoking multiple-complex sensory percepts. Utah Slanted Electrode Arrays (USEAs, 96 recording/stimulating electrodes) were implanted for 30 days into the median (Subject 1-M, 31 years post-amputation) or ulnar (Subject 2-U, 1.5 years post-amputation) nerves of two amputees. Neural activity was recorded during intended movements of the subject's phantom fingers and a linear Kalman filter was used to decode the neural data. Microelectrode stimulation of varying amplitudes and frequencies was delivered via single or multiple electrodes to investigate the number, size and quality of sensory percepts that could be evoked. Device performance over time was assessed by measuring: electrode impedances, signal-to-noise ratios (SNRs), stimulation thresholds, number and stability of evoked percepts. The subjects were able to proportionally, control individual fingers of a virtual robotic hand, with 13 different movements decoded offline (r = 0.48) and two movements decoded online. Electrical stimulation across one USEA evoked >80 sensory percepts. Varying the stimulation parameters modulated percept quality. Devices remained intrafascicularly implanted for the duration of the study with no significant changes in the SNRs or percept thresholds. This study demonstrated that an array of 96 microelectrodes can be implanted into the human peripheral nervous system for up to 1 month durations. Such an array could provide intuitive control of a virtual prosthetic hand with broad sensory feedback.

Restoring motor control and sensory feedback in people with upper extremity amputations using arrays of 96 microelectrodes implanted in the median and ulnar nerves

NASA Astrophysics Data System (ADS)

Davis, T. S.; Wark, H. A. C.; Hutchinson, D. T.; Warren, D. J.; O'Neill, K.; Scheinblum, T.; Clark, G. A.; Normann, R. A.; Greger, B.

2016-06-01

Objective. An important goal of neuroprosthetic research is to establish bidirectional communication between the user and new prosthetic limbs that are capable of controlling >20 different movements. One strategy for achieving this goal is to interface the prosthetic limb directly with efferent and afferent fibres in the peripheral nervous system using an array of intrafascicular microelectrodes. This approach would provide access to a large number of independent neural pathways for controlling high degree-of-freedom prosthetic limbs, as well as evoking multiple-complex sensory percepts. Approach. Utah Slanted Electrode Arrays (USEAs, 96 recording/stimulating electrodes) were implanted for 30 days into the median (Subject 1-M, 31 years post-amputation) or ulnar (Subject 2-U, 1.5 years post-amputation) nerves of two amputees. Neural activity was recorded during intended movements of the subject’s phantom fingers and a linear Kalman filter was used to decode the neural data. Microelectrode stimulation of varying amplitudes and frequencies was delivered via single or multiple electrodes to investigate the number, size and quality of sensory percepts that could be evoked. Device performance over time was assessed by measuring: electrode impedances, signal-to-noise ratios (SNRs), stimulation thresholds, number and stability of evoked percepts. Main results. The subjects were able to proportionally, control individual fingers of a virtual robotic hand, with 13 different movements decoded offline (r = 0.48) and two movements decoded online. Electrical stimulation across one USEA evoked >80 sensory percepts. Varying the stimulation parameters modulated percept quality. Devices remained intrafascicularly implanted for the duration of the study with no significant changes in the SNRs or percept thresholds. Significance. This study demonstrated that an array of 96 microelectrodes can be implanted into the human peripheral nervous system for up to 1 month durations. Such an array could provide intuitive control of a virtual prosthetic hand with broad sensory feedback.

21 CFR 872.3680 - Polytetrafluoroethylene (PTFE) vitreous carbon materials.

Code of Federal Regulations, 2010 CFR

2010-04-01

... the sockets in which teeth are rooted) or intended to coat metal surgical implants to be placed in the alveoli (sockets in which the teeth are rooted) or the temporomandibular joints (the joint between the...

21 CFR 872.3680 - Polytetrafluoroethylene (PTFE) vitreous carbon materials.

Code of Federal Regulations, 2013 CFR

2013-04-01

... the sockets in which teeth are rooted) or intended to coat metal surgical implants to be placed in the alveoli (sockets in which the teeth are rooted) or the temporomandibular joints (the joint between the...

21 CFR 872.3680 - Polytetrafluoroethylene (PTFE) vitreous carbon materials.

Code of Federal Regulations, 2014 CFR

2014-04-01

... the sockets in which teeth are rooted) or intended to coat metal surgical implants to be placed in the alveoli (sockets in which the teeth are rooted) or the temporomandibular joints (the joint between the...

21 CFR 872.3680 - Polytetrafluoroethylene (PTFE) vitreous carbon materials.

Code of Federal Regulations, 2011 CFR

2011-04-01

... the sockets in which teeth are rooted) or intended to coat metal surgical implants to be placed in the alveoli (sockets in which the teeth are rooted) or the temporomandibular joints (the joint between the...

21 CFR 872.3680 - Polytetrafluoroethylene (PTFE) vitreous carbon materials.

Code of Federal Regulations, 2012 CFR

2012-04-01

... the sockets in which teeth are rooted) or intended to coat metal surgical implants to be placed in the alveoli (sockets in which the teeth are rooted) or the temporomandibular joints (the joint between the...

Dataglove measurement of joint angles in sign language handshapes

PubMed Central

Eccarius, Petra; Bour, Rebecca; Scheidt, Robert A.

2012-01-01

In sign language research, we understand little about articulatory factors involved in shaping phonemic boundaries or the amount (and articulatory nature) of acceptable phonetic variation between handshapes. To date, there exists no comprehensive analysis of handshape based on the quantitative measurement of joint angles during sign production. The purpose of our work is to develop a methodology for collecting and visualizing quantitative handshape data in an attempt to better understand how handshapes are produced at a phonetic level. In this pursuit, we seek to quantify the flexion and abduction angles of the finger joints using a commercial data glove (CyberGlove; Immersion Inc.). We present calibration procedures used to convert raw glove signals into joint angles. We then implement those procedures and evaluate their ability to accurately predict joint angle. Finally, we provide examples of how our recording techniques might inform current research questions. PMID:23997644

Does metaphyseal cement augmentation in fracture management influence the adjacent subchondral bone and joint cartilage?: an in vivo study in sheep stifle joints.

PubMed

Goetzen, Michael; Hofmann-Fliri, Ladina; Arens, Daniel; Zeiter, Stephan; Stadelmann, Vincent; Nehrbass, Dirk; Richards, R Geoff; Blauth, Michael

2015-01-01

Augmentation of implants with polymethylmethacrylate (PMMA) bone cement in osteoporotic fractures is a promising approach to increase implant purchase. Side effects of PMMA for the metaphyseal bone, particularly for the adjacent subchondral bone plate and joint cartilage, have not yet been studied. The following experimental study investigates whether subchondral PMMA injection compromises the homeostasis of the subchondral bone and/or the joint cartilage.Ten mature sheep were used to simulate subchondral PMMA injection. Follow-ups of 2 (4 animals) and 4 (6 animals) months were chosen to investigate possible cartilage damage and subchondral plate alterations in the knee. Evaluation was completed by means of high-resolution peripheral quantitative computed tomography (HRpQCT) imaging, histopathological osteoarthritis scoring, and determination of glycosaminoglycan content in the joint cartilage. Results were compared with the untreated contralateral knee and statistically analyzed using nonparametric tests.Evaluation of the histological osteoarthritis score revealed no obvious cartilage damage for the treated knee; median histological score after 2 months 0 (range 4), after 4 months 1 (range 5). There was no significant difference when compared with the untreated control site after 2 and 4 months (P = 0.23 and 0.76, respectively). HRpQCT imaging showed no damage to the metaphyseal trabeculae. Glycosaminoglycan measurements of the treated joint cartilage after 4 months revealed no significant difference compared with the untreated cartilage (P = 0.24).The findings of this study support initial clinical observation that PMMA implant augmentation of metaphyseal fractures appears to be a safe procedure for fixation without harming the subchondral bone plate and adjacent joint cartilage.

Ultrasound of the fingers for human identification using biometrics.

PubMed

Narayanasamy, Ganesh; Fowlkes, J Brian; Kripfgans, Oliver D; Jacobson, Jon A; De Maeseneer, Michel; Schmitt, Rainer M; Carson, Paul L

2008-03-01

It was hypothesized that the use of internal finger structure as imaged using commercially available ultrasound (US) scanners could act as a supplement to standard methods of biometric identification, as well as a means of assessing physiological and cardiovascular status. Anatomical structures in the finger including bone contour, tendon and features along the interphalangeal joint were investigated as potential biometric identifiers. Thirty-six pairs of three-dimensional (3D) gray-scale images of second to fourth finger (index, middle and ring) data taken from 20 individuals were spatially registered using MIAMI-Fuse software developed at our institution and also visually matched by four readers. The image-based registration met the criteria for matching successfully in 14 out of 15 image pairs on the same individual and did not meet criteria for matching in any of the 12 image pairs from different subjects, providing a sensitivity and specificity of 0.93 and 1.00, respectively. Visual matching of all image pairs by four readers yielded 96% successful match. Power Doppler imaging was performed to calculate the change in color pixel density due to physical exercise as a surrogate of stress level and to provide basic physiological information. (E-mail: gnarayan@umich.edu).

[Clinical Trial to Test the iFuse Implant System® in Patients with Sacroiliac Joint Syndrome: One Year Results].

PubMed

Bornemann, R; Pflugmacher, R; Webler, M; Koch, E M W; Dengler, J; Wirtz, D C; Frey, S P

2016-12-01

Background: This study reports one year post-operative monitoring of the efficacy and safety of iFuse Implant System® in patients with sacroiliac joint syndrome. Material and Methods: After 6 months of inadequate conservative treatment, patients with properly proven ISG syndrome were selected for surgery. The iFuse implants had a triangular profile and coating of porous titanium plasma spray and were used in the minimally invasive procedures. The procedure was performed under general anaesthesia and fluoroscopic control. In each case, three implants were placed. Results: 24 patients (22 f; 92 %; 54.9 ± 14 years) participated in the study. The operations were performed in 11 patients (46 %) on the left and in 13 patients (54 %) on the right. The mean operative time was 42.4 minutes (95 % CI: 35.6-49.3). The reduction in pain intensity on the VAS scale was 58 ± 11 mm (68 ± 7 %). The Oswestry score showed a median decrease of 44 percentage points (57 %). After 12 months, 15 patients (63 %) reported that they were taking no more painkillers. Conclusion: The minimally invasive treatment of patients with sacroiliac joint syndrome using the iFuse Implant System leads to significant analgesic effects over the period of one year; it also contributes significantly to improving the functioning of the patient. Georg Thieme Verlag KG Stuttgart · New York.

Effect of lubricant on the reliability of dental implant abutment screw joint: An in vitro laboratory and three-dimension finite element analysis.

PubMed

Wu, Tingting; Fan, Hongyi; Ma, Ruiyang; Chen, Hongyu; Li, Zhi; Yu, Haiyang

2017-06-01

Biomechanical factors play a key role in the success of dental implants. Fracture and loosening of abutment screws are major issues. This study investigated the effect of lubricants on the stability of dental implant-abutment connection. As lubricants, graphite and vaseline were coated on the abutment screw surface, respectively, and a blank without lubricant served as the control. The total friction coefficient (μ tot ), clamping force, fatigue behavior and detorque of the joint combined with dynamic cyclic loading were measured under different lubricating conditions. Further, a three-dimensional finite element analysis was used to investigate stress distribution, in conjunction with experimental images. The results showed that the lubricant reduced μ tot , which in turn led to an increase in clamping force. Decrease in loading increased the fatigue life of the screw. However, use of lubricant at high load reduced the fatigue life. Ductile fracture at the first thread of the screw was the chief failure mode, which was due to maximum von Mises stress. Higher stress levels occurred in the lubricant groups. Lubricated screws resulted in lower detorque which made the joint easier to loosen. In conclusion, the lubricant cannot effectively improve the reliability of dental implant-abutment connection. Keeping the interfaces of implant-screw uncontaminated and strengthening the surface of the screw may be recommend for clinical operation and future design. Copyright © 2016 Elsevier B.V. All rights reserved.

The mean seven years' results of the use of poly-L/D-lactic acid (PLDLA) interposition implant and bone packing in revision metacarpophalangeal arthroplasty: a prospective cohort study.

PubMed

Tiihonen, R; Honkanen, P B; Belt, E A; Ikävalko, M; Skyttä, E T

2012-01-01

Revision arthroplasty of metacarpophalangeal (MCP) joints in chronic inflammatory arthritis patients after silicone implants is challenging due of severe bone loss and soft tissue deficiencies. The aim of this study was to evaluate the outcome of revision MCP arthroplasty using poly-L/D-lactic acid 96:4 (PLDLA) interposition implant and morcelised allograft or autograft bone packing in patients with failed MCP arthroplasties and severe osteolysis. The study group consisted of 15 patients (15 hands and 36 joints) at a mean follow-up of seven years (range 5-10 years). The radiographs were reviewed for osteolysis and incorporation of the grafted bone. The clinical assessments included active range of motion, evaluation of pain, subjective outcome and assessment of grip power. PLDLA interposition arthroplasty combined with bone packing provided satisfactory pain relief, but function was limited. Radiographic analysis showed complete incorporation of the grafted bone to the diaphyseal portion of the host metacarpal and phalangeal bones in 30 of the 36 joints. All the patients had very limited grip strength, both on the operated and non-operated side. Due to soft tissue deficiencies long-term function and alignment problems can not be resolved with PLDLA interposition implant.

Combined chemical and mechanical effects on free radicals in UHMWPE joints during implantation.

PubMed

Jahan, M S; Wang, C; Schwartz, G; Davidson, J A

1991-08-01

An electron spin resonance (ESR) technique is employed to determine the free radical distribution in the articulating surfaces of retrieved acetabular cups and knee-joint plateaus (retrieved after more than 6 years of implantation). Similar measurements made on samples prepared from cyclically stressed and unstressed cups, and on samples following oxidations in nitric acid and intralipid solutions provided sufficient data to gain more knowledge about the combined chemical and mechanical effects on PE free radicals during implantation. In UHMWPE free radicals are primarily initiated by gamma-ray sterilization; however, during implantation, peroxy (scission type) free radicals are formed and reach a maximum concentration level (equilibrium state) due to oxidation by chemical (hemoglobin and/or synovial fluids) environment of the joints. Subsequently, due to frictional heating and stress in the loading zones, free radical reaction is accelerated and their number is reduced only in those areas. This is consistent with the observations of a temperature rise in acetabular cups during in vitro frictional wear stress tests and in vivo telemetry observations, as reported by others. Compared with the previously reported SEM micrographs the low-free-radical regions are correlated with high-wear areas and the high-free-radical regions with the low-wear areas.

Effect of skin-transmitted vibration enhancement on vibrotactile perception.

PubMed

Tanaka, Yoshihiro; Ueda, Yuichiro; Sano, Akihito

2015-06-01

Vibration on skin elicited by the mechanical interaction of touch between the skin and an object propagates to skin far from the point of contact. This paper investigates the effect of skin-transmitted vibration on vibrotactile perception. To enhance the transmission of high-frequency vibration on the skin, stiff tape was attached to the skin so that the tape covered the bottom surface of the index finger from the periphery of the distal interphalangeal joint to the metacarpophalangeal joint. Two psychophysical experiments with high-frequency vibrotactile stimuli of 250 Hz were conducted. In the psychophysical experiments, discrimination and detection thresholds were estimated and compared between conditions of the presence or the absence of the tape (normal bare finger). A method of limits was applied for the detection threshold estimation, and the discrimination task using a reference stimulus and six test stimuli with different amplitudes was applied for the discrimination threshold estimation. The stimulation was given to bare fingertips of participants. Result showed that the detection threshold was enhanced by attaching the tape, and the discrimination threshold enhancement by attaching the tape was confirmed for participants who have relatively large discrimination threshold under normal bare finger. Then, skin-transmitted vibration was measured with an accelerometer with the psychophysical experiments. Result showed that the skin-transmitted vibration when the tape was attached to the skin was larger than that when normal bare skin. There is a correlation between the increase in skin-transmitted vibration and the enhancement of the discrimination threshold.

[The development of research in tribology of artificial joints].

PubMed

Dai, Zhendong; Gong, Juanqing

2006-06-01

Aseptic loosening of the prosthesis is a major form for the failure of artificial joints, which results in the conglomeration of wear particles at the bone-implant interface. This paper briefly reviews the recent development of tribology of artificial joints preserving good lubrication, enhancing the wear resistance of materials for the joints, reducing the generation of sensitive-size particles and depressing the debris-tissue reactions. Suggestion for improvement in the design of artificial joints is presented.

Consciousness recovery induced by intrathecal baclofen administration after subarachnoid hemorrhage -two case reports-.

PubMed

Oyama, Hirofumi; Kito, Akira; Maki, Hideki; Hattori, Kenichi; Tanahashi, Kuniaki

2010-01-01

Two patients with subarachnoid hemorrhage recovered consciousness after intrathecal baclofen administration using an implanted intrathecal baclofen pump delivering 50 microg per day using a simple infusion mode. Intrathecal baclofen resulted in significant reduction of spasticity 3 months after the implantation. Case 1 was reduced to a completely bedridden state with spasticity and could slightly move her fingers following commands. However, the patient could eat food and wash her face with minimal assistance at 3 months after the implantation, and could stand up in the parallel bars with assistance and speak several words at 8 months. Case 2 was in a completely bedridden state at 10 months after onset and could neither drink water nor follow instructions. However, the patient became oriented and could eat by herself within 3 to 4 weeks of implantation. She could walk with a cane and use the stairs with minimal assistance at 2 and 3 months after implantation. The patient could speak fluently within 6 months of implantation. Flatulence and dysuria happened during the screening test, but these symptoms were not repeated after implantation of a pump-catheter-system and continuous intrathecal baclofen infusion. Continuous intrathecal baclofen infusion caused both improvement in muscle tone and spasms and consciousness recovery from the vegetative state. This therapy is a strong candidate treatment for patients with spasticity and consciousness disturbance.

Detection of rheumatoid arthritis in humans by fluorescence imaging

NASA Astrophysics Data System (ADS)

Ebert, Bernd; Dziekan, Thomas; Weissbach, Carmen; Mahler, Marianne; Schirner, Michael; Berliner, Birgitt; Bauer, Daniel; Voigt, Jan; Berliner, Michael; Bahner, Malte L.; Macdonald, Rainer

2010-02-01

The blood pool agent indo-cyanine green (ICG) has been investigated in a prospective clinical study for detection of rheumatoid arthritis using fluorescence imaging. Temporal behavior as well as spatial distribution of fluorescence intensity are suited to differentiate healthy and inflamed finger joints after i.v. injection of an ICG bolus.

LASER BIOLOGY AND MEDICINE: Light scattering study of rheumatoid arthritis

NASA Astrophysics Data System (ADS)

Beuthan, J.; Netz, U.; Minet, O.; Klose, Annerose D.; Hielscher, A. H.; Scheel, A.; Henniger, J.; Müller, G.

2002-11-01

The distribution of light scattered by finger joints is studied in the near-IR region. It is shown that variations in the optical parameters of the tissue (scattering coefficient μs, absorption coefficient μa, and anisotropy factor g) depend on the presence of the rheumatoid arthritis (RA). At the first stage, the distribution of scattered light was measured in diaphanoscopic experiments. The convolution of a Gaussian error function with the scattering phase function proved to be a good approximation of the data obtained. Then, a new method was developed for the reconstruction of distribution of optical parameters in the finger cross section. Model tests of the quality of this reconstruction method show good results.

Virtual three-dimensional blackboard: three-dimensional finger tracking with a single camera

NASA Astrophysics Data System (ADS)

Wu, Andrew; Hassan-Shafique, Khurram; Shah, Mubarak; da Vitoria Lobo, N.

2004-01-01

We present a method for three-dimensional (3D) tracking of a human finger from a monocular sequence of images. To recover the third dimension from the two-dimensional images, we use the fact that the motion of the human arm is highly constrained owing to the dependencies between elbow and forearm and the physical constraints on joint angles. We use these anthropometric constraints to derive a 3D trajectory of a gesticulating arm. The system is fully automated and does not require human intervention. The system presented can be used as a visualization tool, as a user-input interface, or as part of some gesture-analysis system in which 3D information is important.

Decoding of human hand actions to handle missing limbs in neuroprosthetics.

PubMed

Belić, Jovana J; Faisal, A Aldo

2015-01-01

The only way we can interact with the world is through movements, and our primary interactions are via the hands, thus any loss of hand function has immediate impact on our quality of life. However, to date it has not been systematically assessed how coordination in the hand's joints affects every day actions. This is important for two fundamental reasons. Firstly, to understand the representations and computations underlying motor control "in-the-wild" situations, and secondly to develop smarter controllers for prosthetic hands that have the same functionality as natural limbs. In this work we exploit the correlation structure of our hand and finger movements in daily-life. The novelty of our idea is that instead of averaging variability out, we take the view that the structure of variability may contain valuable information about the task being performed. We asked seven subjects to interact in 17 daily-life situations, and quantified behavior in a principled manner using CyberGlove body sensor networks that, after accurate calibration, track all major joints of the hand. Our key findings are: (1) We confirmed that hand control in daily-life tasks is very low-dimensional, with four to five dimensions being sufficient to explain 80-90% of the variability in the natural movement data. (2) We established a universally applicable measure of manipulative complexity that allowed us to measure and compare limb movements across tasks. We used Bayesian latent variable models to model the low-dimensional structure of finger joint angles in natural actions. (3) This allowed us to build a naïve classifier that within the first 1000 ms of action initiation (from a flat hand start configuration) predicted which of the 17 actions was going to be executed-enabling us to reliably predict the action intention from very short-time-scale initial data, further revealing the foreseeable nature of hand movements for control of neuroprosthetics and tele operation purposes. (4) Using the Expectation-Maximization algorithm on our latent variable model permitted us to reconstruct with high accuracy (<5-6° MAE) the movement trajectory of missing fingers by simply tracking the remaining fingers. Overall, our results suggest the hypothesis that specific hand actions are orchestrated by the brain in such a way that in the natural tasks of daily-life there is sufficient redundancy and predictability to be directly exploitable for neuroprosthetics.

OSTEOLYSIS AROUND TOTAL KNEE ARTHOPLASTY: A REVIEW OF PATHOGENETIC MECHANISMS

PubMed Central

Gallo, Jiri; Goodman, Stuart B.; Konttinen, Yrjö T.; Wimmer, Markus A.; Holinka, Martin

2014-01-01

Aseptic loosening and other wear-related complications are one of the most frequent late reasons for revision of total knee arthroplasty (TKA). Periprosthetic osteolysis (PPOL) predates aseptic loosening in many cases indicating the clinical significance of this pathogenic mechanism. A variety of implant-, surgery-, and host-related factors have been delineated to explain the development of PPOL. These factors influence the development of PPOL due to changes in mechanical stresses within the vicinity of the prosthetic device, excessive wear of the polyethylene liner, and joint fluid pressure and flow acting on the peri-implant bone. The process of aseptic loosening is initially governed by factors such as implant/limb alignment, device fixation quality, and muscle coordination/strength. Later large numbers of wear particles detached from TKAs trigger and perpetuate particle disease, as highlighted by progressive growth of inflammatory/granulomatous tissue around the joint cavity. An increased accumulation of osteoclasts at the bone-implant interface, an impairment of osteoblast function, mechanical stresses, and an increased production of joint fluid contribute to bone resorption and subsequent loosening of the implant. In addition, hypersensitivity and adverse reactions to metal debris may contribute to aseptic TKA failure but should be determined more precisely. Patient activity level appears to be the most important factor when the long-term development of PPOL is considered. Surgical technique, implant design, and material factors are the most important preventative factors because they influence both the generation of wear debris and excessive mechanical stresses. New generations of bearing surfaces and designs for TKA should carefully address these important issues in extensive preclinical studies. Currently, there is little evidence that PPOL can be prevented with pharmacological interventions. PMID:23669623

Design and Fabrication of a Universal Soft Gripper

NASA Astrophysics Data System (ADS)

Sabzehzar, Amin

Inspired from nature, soft robots capable of actively tuning their mechanical rigidity can rapidly transition between a broad range of motor tasks, from lifting heavy loads to dexterous manipulation of delicate objects. Reversible rigidity tuning also enables soft robotic actuators to reroute their internal loading and alter their mode of deformation in response to intrinsic activation. In this study, we demonstrate this principle with a three-fingered pneumatic gripper that contains programmable ligaments that change stiness when activated with electrical current. The ligaments are composed of a conductive thermoplastic elastomer composite that reversibly softens under resistive heating. Depending on which ligaments are activated, the gripper will bend inward to pick up an object, bend laterally to twist it, or bend outward to release it. Each finger consists of three PDMS phalanges that are attached with two Ecoflex joints. Three ligaments (strips of a cPBE-PDMS composite layer) are attached along the finger and are stimulated with electricity individually. When the high pressure air is injected in the hollow middle part of the finger, the finger will be bent in the opposite direction of the stimulated cPBE-PDMS element (softer wall). This enables the gripper's fingers to grab and twist objects with dierent sizes and shapes. All of the gripper motions are generated with a single pneumatic source of pressure and are controlled with an electrical board. The ability to incorporate electrically programmable ligaments in pneumatic or hydraulic actuators has the potential to enhance versatility and reduce dependency on tubing and valves. In this study, an activation/deactivation cycle can be completed within 15 s.

Cemented total knee replacement in 24 dogs: surgical technique, clinical results, and complications.

PubMed

Allen, Matthew J; Leone, Kendall A; Lamonte, Kimberly; Townsend, Katy L; Mann, Kenneth A

2009-07-01

To characterize the performance of cemented total knee replacement (TKR) in dogs. Preclinical research study. Skeletally mature, male Hounds (25-30 kg; n=24) with no preexisting joint pathology. Dogs had unilateral cemented TKR and were evaluated at 6, 12, 26, or 52 weeks (6 dogs/time point) by radiography, bone density analysis, visual gait assessment, and direct measurement of thigh circumference and stifle joint range of motion as indicators of functional recovery. At study end, the stability of the cemented tibial component was determined by destructive mechanical testing. Joint stability was excellent in 16 dogs (67%) and good in 8 dogs. None of the tibial components had evidence of migration or periprosthetic osteolysis whereas 1 femoral component was loose at 52 weeks. There was an early and significant decrease in tibial bone density, likely because of disuse of the operated limb. Dogs returned to full activity by 12 weeks. The tibial cement-bone interface maintained its strength over 52 weeks. Cement provides stable fixation of the tibial component in canine TKR. Cemented TKR yields adequate clinical function and stifle joint excursion in the dog. Clinical studies are needed to determine the long-term fate of cemented TKR implants, to assess the influence of implant design on implant fixation and wear, and to obtain objective functional data.

Collagenase Treatment in Dupuytren Contractures: A Review of the Current State Versus Future Needs.

PubMed

Degreef, Ilse

2016-06-01

Dupuytren disease is highly prevalent and the finger contractures can be very extensile, compromising the patients' hand function. To restore full function, contractures have been addressed by cutting the causative strands for nearly 200 years, ever since Baron Guillaume Dupuytren demonstrated his technique at the beginning of the nineteenth century. Surgery can be minimal (fasciotomy) or quite invasive (fasciectomy and even skin replacement). However, in the last decade translational research has introduced the non-surgical technique of enzymatic fasciotomy with collagenase injections. Now, finger contractures can be released with single injections on monthly intervals, to address one joint contracture at a time. However, in hands affected with Dupuytren contractures to the extent that the patient calls for treatment, most often more than one joint is involved. In surgical treatment options all contracted joints are addressed in a single procedure. Nevertheless, extensile surgery withholds inherent risks of complications and intense rehabilitation. Today, the minimally-invasive method with enzymatic fasciotomy by collagenase injection has demonstrated reliable outcomes with few morbidities and early recovery. However, single-site injection is todays' standard procedure and multiple joints are addressed in several sessions with monthly intervals. This triggers a longer recovery and treatment burden in severely affected hands even though surgery is avoided. Therefore, further treatment modalities of collagenase use are explored. Adjustments in the treatment regimes' flexibility and collagenase injections addressing more than one joint contracture simultaneously will improve the burden of multiple sessions and, therefore, enzymatic fasciotomy may become the preferred method in more extensile Dupuytren contractures. In this independent review, the challenge of Dupuytren disease affecting a single versus multiple joints is presented. The pros and cons of collagenase use are weighed, founded by the available scientific background. The demands and options for collagenase in future treatment regimens for extensile Dupuytren contractures are discussed.

[Evaluation of Artificial Hip Joint with Radiofrequency Heating Issues during MRI Examination: A Comparison between 1.5 T and 3 T].

PubMed

Yamazaki, Masaru; Ideta, Takahiro; Kudo, Sadahiro; Nakazawa, Masami

2016-06-01

In magnetic resonance imaging (MRI), when radiofrequency (RF) is irradiated to a subject with metallic implant, it can generate heat by RF irradiation. Recently 3 T MRI scanner has spread widely and imaging for any regions of whole body has been conducted. However specific absorption rate (SAR) of 3 T MRI becomes approximately four times as much as the 1.5 T, which can significantly affect the heat generation of metallic implants. So, we evaluated RF heating of artificial hip joints in different shapes and materials in 1.5 T and 3 T MRI. Three types of artificial hip joints made of stainless alloy, titanium alloy and cobalt chrome alloy were embedded in the human body-equivalent phantom respectively and their temperature change were measured for twenty minutes by 1.5 T and 3 T MRI. The maximum temperature rise was observed at the bottom head in all of three types of artificial hip joints, the rise being 12°C for stainless alloy, 11.9°C for titanium alloy and 6.1°C for cobalt chrome alloy in 1.5 T. The temperature rise depended on SAR and the increase of SAR had a good linear relationship with the temperature rise. It was found from the result that the RF heating of metallic implants can take place in various kinds of material and the increase of SAR has a good linear relationship with the temperature rise. This experience shows that reduction of SAR can decrease temperature of metallic implants.

Development of a parametric kinematic model of the human hand and a novel robotic exoskeleton.

PubMed

Burton, T M W; Vaidyanathan, R; Burgess, S C; Turton, A J; Melhuish, C

2011-01-01

This paper reports the integration of a kinematic model of the human hand during cylindrical grasping, with specific focus on the accurate mapping of thumb movement during grasping motions, and a novel, multi-degree-of-freedom assistive exoskeleton mechanism based on this model. The model includes thumb maximum hyper-extension for grasping large objects (~> 50 mm). The exoskeleton includes a novel four-bar mechanism designed to reproduce natural thumb opposition and a novel synchro-motion pulley mechanism for coordinated finger motion. A computer aided design environment is used to allow the exoskeleton to be rapidly customized to the hand dimensions of a specific patient. Trials comparing the kinematic model to observed data of hand movement show the model to be capable of mapping thumb and finger joint flexion angles during grasping motions. Simulations show the exoskeleton to be capable of reproducing the complex motion of the thumb to oppose the fingers during cylindrical and pinch grip motions. © 2011 IEEE

An Architecture for Measuring Joint Angles Using a Long Period Fiber Grating-Based Sensor

PubMed Central

Perez-Ramirez, Carlos A.; Almanza-Ojeda, Dora L.; Guerrero-Tavares, Jesus N.; Mendoza-Galindo, Francisco J.; Estudillo-Ayala, Julian M.; Ibarra-Manzano, Mario A.

2014-01-01

The implementation of signal filters in a real-time form requires a tradeoff between computation resources and the system performance. Therefore, taking advantage of low lag response and the reduced consumption of resources, in this article, the Recursive Least Square (RLS) algorithm is used to filter a signal acquired from a fiber-optics-based sensor. In particular, a Long-Period Fiber Grating (LPFG) sensor is used to measure the bending movement of a finger. After that, the Gaussian Mixture Model (GMM) technique allows us to classify the corresponding finger position along the motion range. For these measures to help in the development of an autonomous robotic hand, the proposed technique can be straightforwardly implemented on real time platforms such as Field Programmable Gate Array (FPGA) or Digital Signal Processors (DSP). Different angle measurements of the finger's motion are carried out by the prototype and a detailed analysis of the system performance is presented. PMID:25536002

Upper limb congenital muscular hypertrophy and aberrant muscle syndrome in children.

PubMed

Dahan, Emmanuel; Chaves, Camilo; Bachy, Manon; Fitoussi, Frank

2018-01-01

Congenital muscle hypertrophy of the upper limb is a very rare condition with unknown aetiology. This descriptive observational and retrospective series included eight children followed by a multidisciplinary team from 2005 to 2017. The diagnosis was based on a cluster of clinical and radiological characteristics after elimination of differential diagnoses. Patients were categorized according to: anomalies of the wrist, anomalies of long fingers of intrinsic or extrinsic origin; and anomalies of the thumb with or without first web space contracture. Treatment begins in young children with hand orthoses to limit muscle contraction and joint malposition. The purpose of surgical treatment was to release contractures and to restore muscle balance through, in the main, finger intrinsic releases and first web releases. At the 2-year follow-up, we found that limited surgical procedures improved finger, thumb and wrist positions. We conclude that muscle hypertrophy is the main cause of deformity and that selective releases of contracted musculo-tendinous units and skin lengthening are effective. IV.

Rehabilitation for bilateral amputation of fingers

USGS Publications Warehouse

Stapanian, Martin A.; Stapanian, Adrienne M.P.; Staley, Keith E.

2010-01-01

We describe reconstructive surgeries, therapy, prostheses, and adaptations for a patient who experienced bilateral amputation of all five fingers of both hands through the proximal phalanges in January 1992. The patient made considerable progress in the use of his hands in the 10 mo after amputation, including nearly a 120% increase in the active range of flexion of metacarpophalangeal joints. In late 1992 and early 1993, the patient had "on-top plasty" surgeries, in which the index finger remnants were transferred onto the thumb stumps, performed on both hands. The increased web space and functional pinch resulting from these procedures made many tasks much easier. The patient and occupational therapists set challenging goals at all times. Moreover, the patient was actively involved in the design and fabrication of all prostheses and adaptations or he developed them himself. Although he was discharged from occupational therapy in 1997, the patient continues to actively find new solutions for prehension and grip strength 18 yr after amputation.

Economic implications of implant selection.

PubMed

DeFronzo, D J; Landsman, A S; Ghareeb, J A

1995-07-01

Numerous types of implantable biomaterials are available for a variety of applications. Although much has been written about the physical properties or biocompatibility issues, very few papers have focused on the economic feasibility of these materials. This article assesses financial factors associated with first metatarsophalangeal total joint prostheses.

Acromioclavicular joint reconstruction using the LockDown synthetic implant: a study with cadavers.

PubMed

Taranu, R; Rushton, P R P; Serrano-Pedraza, I; Holder, L; Wallace, W A; Candal-Couto, J J

2015-12-01

Dislocation of the acromioclavicular joint is a relatively common injury and a number of surgical interventions have been described for its treatment. Recently, a synthetic ligament device has become available and been successfully used, however, like other non-native solutions, a compromise must be reached when choosing non-anatomical locations for their placement. This cadaveric study aimed to assess the effect of different clavicular anchorage points for the Lockdown device on the reduction of acromioclavicular joint dislocations, and suggest an optimal location. We also assessed whether further stability is provided using a coracoacromial ligament transfer (a modified Neviaser technique). The acromioclavicular joint was exposed on seven fresh-frozen cadaveric shoulders. The joint was reconstructed using the Lockdown implant using four different clavicular anchorage points and reduction was measured. The coracoacromial ligament was then transferred to the lateral end of the clavicle, and the joint re-assessed. If the Lockdown ligament was secured at the level of the conoid tubercle, the acromioclavicular joint could be reduced anatomically in all cases. If placed medial or 2 cm lateral, the joint was irreducible. If the Lockdown was placed 1 cm lateral to the conoid tubercle, the joint could be reduced with difficulty in four cases. Correct placement of the Lockdown device is crucial to allow anatomical joint reduction. Even when the Lockdown was placed over the conoid tubercle, anterior clavicle displacement remained but this could be controlled using a coracoacromial ligament transfer. ©2015 The British Editorial Society of Bone & Joint Surgery.

Precision of fit between implant impression coping and implant replica pairs for three implant systems.

PubMed

Nicoll, Roxanna J; Sun, Albert; Haney, Stephan; Turkyilmaz, Ilser

2013-01-01

The fabrication of an accurately fitting implant-supported fixed prosthesis requires multiple steps, the first of which is assembling the impression coping on the implant. An imprecise fit of the impression coping on the implant will cause errors that will be magnified in subsequent steps of prosthesis fabrication. The purpose of this study was to characterize the 3-dimensional (3D) precision of fit between impression coping and implant replica pairs for 3 implant systems. The selected implant systems represent the 3 main joint types used in implant dentistry: external hexagonal, internal trilobe, and internal conical. Ten impression copings and 10 implant replicas from each of the 3 systems, B (Brånemark System), R (NobelReplace Select), and A (NobelActive) were paired. A standardized aluminum test body was luted to each impression coping, and the corresponding implant replica was embedded in a stone base. A coordinate measuring machine was used to quantify the maximum range of displacement in a vertical direction as a function of the tightening force applied to the guide pin. Maximum angular displacement in a horizontal plane was measured as a function of manual clockwise or counterclockwise rotation. Vertical and rotational positioning was analyzed by using 1-way analysis of variance (ANOVA). The Fisher protected least significant difference (PLSD) multiple comparisons test of the means was applied when the F-test in the ANOVA was significant (α=.05). The mean and standard deviation for change in the vertical positioning of impression copings was 4.3 ±2.1 μm for implant system B, 2.8 ±4.2 μm for implant system R, and 20.6 ±8.8 μm for implant system A. The mean and standard deviation for rotational positioning was 3.21 ±0.98 degrees for system B, 2.58 ±1.03 degrees for system R, and 5.30 ±0.79 degrees for system A. The P-value for vertical positioning between groups A and B and between groups A and R was <.001. No significant differences were found for vertical positioning between groups B and R. The P-value for rotational positioning between groups A and B and between groups A and R was <.001. No significant differences were found for rotational positioning between groups B and R. The results of the study confirmed that implant systems differ in precision of fit. Vertical precision between paired implant components is a function of joint type and the tightening force applied to the guide pin. The magnitude of vertical displacement with applied torque is greater for conical connections than for butt joint connections. The rotational freedom between paired components is unique to the implant system and is presumably related to the machining tolerances specified by the manufacturer. Copyright © 2013 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

Sacroiliac Joint Fusion Using Triangular Titanium Implants vs. Non-Surgical Management: Six-Month Outcomes from a Prospective Randomized Controlled Trial.

PubMed

Whang, Peter; Cher, Daniel; Polly, David; Frank, Clay; Lockstadt, Harry; Glaser, John; Limoni, Robert; Sembrano, Jonathan

2015-01-01

Sacroiliac (SI) joint pain is a prevalent, underdiagnosed cause of lower back pain. SI joint fusion can relieve pain and improve quality of life in patients who have failed nonoperative care. To date, no study has concurrently compared surgical and non-surgical treatments for chronic SI joint dysfunction. We conducted a prospective randomized controlled trial of 148 subjects with SI joint dysfunction due to degenerative sacroiliitis or sacroiliac joint disruptions who were assigned to either minimally invasive SI joint fusion with triangular titanium implants (N=102) or non-surgical management (NSM, n=46). SI joint pain scores, Oswestry Disability Index (ODI), Short-Form 36 (SF-36) and EuroQol-5D (EQ-5D) were collected at baseline and at 1, 3 and 6 months after treatment commencement. Six-month success rates, defined as the proportion of treated subjects with a 20-mm improvement in SI joint pain in the absence of severe device-related or neurologic SI joint-related adverse events or surgical revision, were compared using Bayesian methods. Subjects (mean age 51, 70% women) were highly debilitated at baseline (mean SI joint VAS pain score 82, mean ODI score 62). Six-month follow-up was obtained in 97.3%. By 6 months, success rates were 81.4% in the surgical group vs. 23.9% in the NSM group (difference of 56.6%, 95% posterior credible interval 41.4-70.0%, posterior probability of superiority >0.999). Clinically important (≥15 point) ODI improvement at 6 months occurred in 75% of surgery subjects vs. 27.3% of NSM subjects. At six months, quality of life improved more in the surgery group and satisfaction rates were high. The mean number of adverse events in the first six months was slightly higher in the surgical group compared to the non-surgical group (1.3 vs. 1.0 events per subject, p=0.1857). Six-month follow-up from this level 1 study showed that minimally invasive SI joint fusion using triangular titanium implants was more effective than non-surgical management in relieving pain, improving function and improving quality of life in patients with SI joint dysfunction due to degenerative sacroiliitis or SI joint disruptions. Minimally invasive SI joint fusion is an acceptable option for patients with chronic SI joint dysfunction due to degenerative sacroiliitis and sacroiliac joint disruptions unresponsive to non-surgical treatments.

Sacroiliac Joint Fusion Using Triangular Titanium Implants vs. Non-Surgical Management: Six-Month Outcomes from a Prospective Randomized Controlled Trial

PubMed Central

Whang, Peter; Polly, David; Frank, Clay; Lockstadt, Harry; Glaser, John; Limoni, Robert; Sembrano, Jonathan

2015-01-01

Background Sacroiliac (SI) joint pain is a prevalent, underdiagnosed cause of lower back pain. SI joint fusion can relieve pain and improve quality of life in patients who have failed nonoperative care. To date, no study has concurrently compared surgical and non-surgical treatments for chronic SI joint dysfunction. Methods We conducted a prospective randomized controlled trial of 148 subjects with SI joint dysfunction due to degenerative sacroiliitis or sacroiliac joint disruptions who were assigned to either minimally invasive SI joint fusion with triangular titanium implants (N=102) or non-surgical management (NSM, n=46). SI joint pain scores, Oswestry Disability Index (ODI), Short-Form 36 (SF-36) and EuroQol-5D (EQ-5D) were collected at baseline and at 1, 3 and 6 months after treatment commencement. Six-month success rates, defined as the proportion of treated subjects with a 20-mm improvement in SI joint pain in the absence of severe device-related or neurologic SI joint-related adverse events or surgical revision, were compared using Bayesian methods. Results Subjects (mean age 51, 70% women) were highly debilitated at baseline (mean SI joint VAS pain score 82, mean ODI score 62). Six-month follow-up was obtained in 97.3%. By 6 months, success rates were 81.4% in the surgical group vs. 23.9% in the NSM group (difference of 56.6%, 95% posterior credible interval 41.4-70.0%, posterior probability of superiority >0.999). Clinically important (≥15 point) ODI improvement at 6 months occurred in 75% of surgery subjects vs. 27.3% of NSM subjects. At six months, quality of life improved more in the surgery group and satisfaction rates were high. The mean number of adverse events in the first six months was slightly higher in the surgical group compared to the non-surgical group (1.3 vs. 1.0 events per subject, p=0.1857). Conclusions Six-month follow-up from this level 1 study showed that minimally invasive SI joint fusion using triangular titanium implants was more effective than non-surgical management in relieving pain, improving function and improving quality of life in patients with SI joint dysfunction due to degenerative sacroiliitis or SI joint disruptions. Clinical relevance Minimally invasive SI joint fusion is an acceptable option for patients with chronic SI joint dysfunction due to degenerative sacroiliitis and sacroiliac joint disruptions unresponsive to non-surgical treatments. PMID:25785242

Reconstruction of the trapeziometacarpal joint in inflammatory joint disease using interposition of autologous tendon or poly-L-D-lactic acid implants: a prospective clinical trial.

PubMed

Tiihonen, Raine P; Skyttä, Eerik T; Kaarela, Kalevi; Ikävalko, Mikko; Belt, Eero A

2012-04-01

Interposition arthroplasty with bioreplaceable poly-L-D-lactic acid (PLDLA) implants has yielded promising results in reconstruction of rheumatoid hands. In this prospective clinical study we compared the PLDLA implant arthroplasty (n = 17) with that of tendon interposition (n = 12) for destruction of the trapeziometacarpal joint in arthritic patients. There was no significant difference between the two groups preoperatively. At one-year follow-up, the mean pain and function scores were 5 and 13 in the PLDLA group, and 19 and 43 in the tendon interposition group, respectively. At one-year follow-up the visual analogue scale (VAS) for function of the PLDLA group differed significantly from that of the tendon interposition group (p = 0.03). This difference was not found at three months postoperatively, and disappeared again at two-year follow-up. Otherwise, no significant difference was found between the groups in the pain or function scores, functional tests, or range of movement. Bioreplaceable interposition arthroplasty works at least as well as tendon interposition. The operation is easier.

The biological response to orthopedic implants for joint replacement. II: Polyethylene, ceramics, PMMA, and the foreign body reaction

PubMed Central

Gibon, Emmanuel; Córdova, Luis A.; Lu, Laura; Lin, Tzu-Hua; Yao, Zhenyu; Hamadouche, Moussa; Goodman, Stuart B.

2017-01-01

Novel evidence-based prosthetic designs and biomaterials facilitate the performance of highly successful joint replacement (JR) procedures. To achieve this goal, constructs must be durable, biomechanically sound, and avoid adverse local tissue reactions. Different biomaterials such as metals and their alloys, polymers, ceramics, and composites are currently used for JR implants. This review focuses on (1) the biological response to the different biomaterials used for TJR and (2) the chronic inflammatory and foreign-body response induced by byproducts of these biomaterials. A homeostatic state of bone and surrounding soft tissue with current biomaterials for JR can be achieved with mechanically stable, infection free and intact (as opposed to the release of particulate or ionic byproducts) implants. Adverse local tissue reactions (an acute/chronic inflammatory reaction, periprosthetic osteolysis, loosening and subsequent mechanical failure) may evolve when the latter conditions are not met. This article (Part 2 of 2) summarizes the biological response to the non-metallic materials commonly used for joint replacement including polyethylene, ceramics, and polymethylmethacrylate (PMMA), as well as the foreign body reaction to byproducts of these materials. PMID:27080740

High-Tech Hip Implant for Wireless Temperature Measurements In Vivo

PubMed Central

Bergmann, Georg; Graichen, Friedmar; Dymke, Jörn; Rohlmann, Antonius; Duda, Georg N.; Damm, Philipp

2012-01-01

When walking long distances, hip prostheses heat up due to friction. The influence of articulating materials and lubricating properties of synovia on the final temperatures, as well as any potential biological consequences, are unknown. Such knowledge is essential for optimizing implant materials, identifying patients who are possibly at risk of implant loosening, and proving the concepts of current joint simulators. An instrumented hip implant with telemetric data transfer was developed to measure the implant temperatures in vivo. A clinical study with 100 patients is planned to measure the implant temperatures for different combinations of head and cup materials during walking. This study will answer the question of whether patients with synovia with poor lubricating properties may be at risk for thermally induced bone necrosis and subsequent implant failure. The study will also deliver the different friction properties of various implant materials and prove the significance of wear simulator tests. A clinically successful titanium hip endoprosthesis was modified to house the electronics inside its hollow neck. The electronics are powered by an external induction coil fixed around the joint. A temperature sensor inside the implant triggers a timer circuit, which produces an inductive pulse train with temperature-dependent intervals. This signal is detected by a giant magnetoresistive sensor fixed near the external energy coil. The implant temperature is measured with an accuracy of 0.1°C in a range between 20°C and 58°C and at a sampling rate of 2–10 Hz. This rate could be considerably increased for measuring other data, such as implant strain or vibration. The employed technique of transmitting data from inside of a closed titanium implant by low frequency magnetic pulses eliminates the need to use an electrical feedthrough and an antenna outside of the implant. It enables the design of mechanically safe and simple instrumented implants. PMID:22927973

Ultrasound disease activity of bilateral wrist and finger joints at three months reflects the clinical response at six months of patients with rheumatoid arthritis treated with biologic disease-modifying anti-rheumatic drugs.

PubMed

Kawashiri, Shin-Ya; Nishino, Ayako; Shimizu, Toshimasa; Umeda, Masataka; Fukui, Shoichi; Nakashima, Yoshikazu; Suzuki, Takahisa; Koga, Tomohiro; Iwamoto, Naoki; Ichinose, Kunihiro; Tamai, Mami; Nakamura, Hideki; Origuchi, Tomoki; Aoyagi, Kiyoshi; Kawakami, Atsushi

2017-03-01

We evaluated whether the early responsiveness of ultrasound synovitis can predict the clinical response in rheumatoid arthritis (RA) patients treated with biologic disease-modifying anti-rheumatic drugs (bDMARDs). Articular synovitis was assessed by ultrasound at 22 bilateral wrist and finger joints in 39 RA patients treated with bDMARDs. Each joint was assigned a gray-scale (GS) and power Doppler (PD) score from 0 to 3, and the sum of the GS or PD scores was considered to represent the ultrasound disease activity. We investigated the correlation of the change in ultrasound disease activity at three months with the EULAR response criteria at six months. GS and PD scores were significantly decreased at three months (p < 0.0001). The % changes of the GS and PD scores at three months were significantly higher at six months in moderate and good responders compared with non-responders (p < 0.05). These tendencies were numerically more prominent if clinical response was set as good responder or Disease Activity Score 28 remission. Poor improvement of ultrasound synovitis scores had good predictive value for non-responders at six months. The responsiveness of ultrasound disease activity is considered to predict further clinical response in RA patients treated with bDMARDs.

[The spectrum of histomorphological findings related to joint endoprosthetics].

PubMed

Morawietz, L; Krenn, V

2014-11-01

Approximately 230,000 total hip and 170,000 knee joint endoprostheses are implanted in Germany annually of which approximately 10% (i.e. 40,000 interventions per year) are cases of revision surgery. These interventions involve removal of a previously implanted prosthesis which has resulted in complaints and replacement with a new prosthesis. There are manifold reasons for revision surgery, the most common indication being so-called endoprosthesis loosening, which is subdivided into septic and aseptic loosening. Histomorphological studies revealed that periprosthetic tissue from endoprosthesis loosening can be classified into four types (I) wear-particle induced type, (II) infectious type, (III) combined type and (IV) fibrous type. Types I and IV represent aseptic loosening and types II and III septic loosening. Recently, the topic of implant allergy has emerged. The detection of cellular, mostly perivascular lymphocytic infiltrates is discussed as being a sign of an allergic tissue reaction. It has most frequently been observed in type I periprosthetic membranes with a dense load of metal wear, which occurs with metal-on-metal bearings. Apart from endoprosthesis loosening, arthrofibrosis is another complication of joint endoprosthetics and can cause pain and impaired function. Histopathologically, arthrofibrosis can be evaluated by a three-tiered grading system. Furthermore, bone pathologies, such as ossification, osteopenia or osteomyelitis can occur as complications of joint endoprosthetics. This review gives an overview of the whole spectrum of pathological findings in joint endoprosthetics and offers a comprehensive and standardized classification system for routine histopathological diagnostics.

An EMG Interface for the Control of Motion and Compliance of a Supernumerary Robotic Finger

PubMed Central

Hussain, Irfan; Spagnoletti, Giovanni; Salvietti, Gionata; Prattichizzo, Domenico

2016-01-01

In this paper, we propose a novel electromyographic (EMG) control interface to control motion and joints compliance of a supernumerary robotic finger. The supernumerary robotic fingers are a recently introduced class of wearable robotics that provides users additional robotic limbs in order to compensate or augment the existing abilities of natural limbs without substituting them. Since supernumerary robotic fingers are supposed to closely interact and perform actions in synergy with the human limbs, the control principles of extra finger should have similar behavior as human’s ones including the ability of regulating the compliance. So that, it is important to propose a control interface and to consider the actuators and sensing capabilities of the robotic extra finger compatible to implement stiffness regulation control techniques. We propose EMG interface and a control approach to regulate the compliance of the device through servo actuators. In particular, we use a commercial EMG armband for gesture recognition to be associated with the motion control of the robotic device and surface one channel EMG electrodes interface to regulate the compliance of the robotic device. We also present an updated version of a robotic extra finger where the adduction/abduction motion is realized through ball bearing and spur gears mechanism. We have validated the proposed interface with two sets of experiments related to compensation and augmentation. In the first set of experiments, different bimanual tasks have been performed with the help of the robotic device and simulating a paretic hand since this novel wearable system can be used to compensate the missing grasping abilities in chronic stroke patients. In the second set, the robotic extra finger is used to enlarge the workspace and manipulation capability of healthy hands. In both sets, the same EMG control interface has been used. The obtained results demonstrate that the proposed control interface is intuitive and can successfully be used, not only to control the motion of a supernumerary robotic finger but also to regulate its compliance. The proposed approach can be exploited also for the control of different wearable devices that has to actively cooperate with the human limbs. PMID:27891088

Sports Injury-Related Fingers and Thumb Deformity Due to Tendon or Ligament Rupture.

PubMed

Bai, Rong-Jie; Zhang, Hui-Bo; Zhan, Hui-Li; Qian, Zhan-Hua; Wang, Nai-Li; Liu, Yue; Li, Wen-Ting; Yin, Yu-Ming

2018-05-05

Hand injuries are very common in sports, such as skiing and ball sports. One of the major reasons causing hand and finger deformity is due to ligament and tendon injury. The aim of this study was to investigate if the high-resolution 3T magnetic resonance imaging (MRI) can demonstrate the complex anatomy of the fingers and thumb, especially the tendons and ligaments, and provide the accurate diagnosis of clinically important fingers and thumbs deformity due to ligamentous and tendinous injuries during sport activities. Sixteen fresh un-embalmed cadaveric hands were harvested from eight cadavers. A total of 20 healthy volunteers' hands and 44 patients with fingers or thumb deformity due to sports-related injuries were included in this study. All subjects had MR examination with T1-weighted images and proton density-weighted imaging with fat suppression (PD FS) in axial, coronal, and sagittal plane, respectively. Subsequently, all 16 cadaveric hands were sliced into 2-mm thick slab with a band saw (six in coronal plane, six in sagittal plane, and four in axial plane). The correlation of anatomic sections and the MRI characteristics of tendons of fingers and the ulnar collateral ligament (UCL) at the metacarpal phalangeal joint (MCPJ) of thumb between 20 healthy volunteers and 44 patients (confirmed by surgery) were analyzed. The normal ligaments and tendons in 16 cadaveric hands and 20 volunteers' hands showed uniform low-signal intensity on all the sequences of the MRI. Among 44 patients with tendinous and ligamentous injuries in the fingers or thumb, 12 cases with UCL injury at MCPJ of the thumb (Stener lesion = 8 and non-Stener lesion = 4), 6 cases with the central slip injury, 12 cases with terminal tendon injury, and 14 cases with flexor digitorum profundus injury. The ligaments and tendons disruption manifested as increased signal intensity and poor definition, discontinuity, and heterogeneous signal intensity of the involved ligaments and tendons. Sports injury-related fingers and thumb deformity are relatively common. MRI is an accurate method for evaluation of the anatomy and pathologic conditions of the fingers and thumb. It is a useful tool for accurate diagnosis of the sports-related ligaments and tendons injuries in hand.

Intra-Articular Knee Contact Force Estimation During Walking Using Force-Reaction Elements and Subject-Specific Joint Model.

PubMed

Jung, Yihwan; Phan, Cong-Bo; Koo, Seungbum

2016-02-01

Joint contact forces measured with instrumented knee implants have not only revealed general patterns of joint loading but also showed individual variations that could be due to differences in anatomy and joint kinematics. Musculoskeletal human models for dynamic simulation have been utilized to understand body kinetics including joint moments, muscle tension, and knee contact forces. The objectives of this study were to develop a knee contact model which can predict knee contact forces using an inverse dynamics-based optimization solver and to investigate the effect of joint constraints on knee contact force prediction. A knee contact model was developed to include 32 reaction force elements on the surface of a tibial insert of a total knee replacement (TKR), which was embedded in a full-body musculoskeletal model. Various external measurements including motion data and external force data during walking trials of a subject with an instrumented knee implant were provided from the Sixth Grand Challenge Competition to Predict in vivo Knee Loads. Knee contact forces in the medial and lateral portions of the instrumented knee implant were also provided for the same walking trials. A knee contact model with a hinge joint and normal alignment could predict knee contact forces with root mean square errors (RMSEs) of 165 N and 288 N for the medial and lateral portions of the knee, respectively, and coefficients of determination (R2) of 0.70 and -0.63. When the degrees-of-freedom (DOF) of the knee and locations of leg markers were adjusted to account for the valgus lower-limb alignment of the subject, RMSE values improved to 144 N and 179 N, and R2 values improved to 0.77 and 0.37, respectively. The proposed knee contact model with subject-specific joint model could predict in vivo knee contact forces with reasonable accuracy. This model may contribute to the development and improvement of knee arthroplasty.

Neutrophil-derived MRP-14 is up-regulated in infectious osteomyelitis and stimulates osteoclast generation.

PubMed

Dapunt, Ulrike; Giese, Thomas; Maurer, Susanne; Stegmaier, Sabine; Prior, Birgit; Hänsch, G Maria; Gaida, Matthias M

2015-10-01

Bone infections of patients with joint replacement by endoprosthesis (so called "periprosthetic joint infection") pose a severe problem in the field of orthopedic surgery. The diagnosis is often difficult, and treatment is, in most cases, complicated and prolonged. Patients often require an implant exchange surgery, as the persistent infection and the accompanying inflammation lead to tissue damage with bone degradation and consequently, to a loosening of the implant. To gain insight into the local inflammatory process, expression of the proinflammatory cytokine MRP-14, a major content of neutrophils, and its link to subsequent bone degradation was evaluated. We found MRP-14 prominently expressed in the affected tissue of patients with implant-associated infection, in close association with the chemokine CXCL8 and a dense infiltrate of neutrophils and macrophages. In addition, the number of MRP-14-positive cells correlated with the presence of bone-resorbing osteoclasts. MRP-14 plasma concentrations were significantly higher in patients with implant-associated infection compared with patients with sterile inflammation or healthy individuals, advocating MRP-14 as a novel diagnostic marker. A further biologic activity of MRP-14 was detected: rMRP-14 directly induced the differentiation of monocytes to osteoclasts, thus linking the inflammatory response in implant infections with osteoclast generation, bone degradation, and implant loosening. © Society for Leukocyte Biology.

Influence of implant neck design on facial bone crest dimensions in the esthetic zone analyzed by cone beam CT: a comparative study with a 5-to-9-year follow-up.

PubMed

Chappuis, Vivianne; Bornstein, Michael M; Buser, Daniel; Belser, Urs

2016-09-01

To examine the influence of two different neck designs on facial bone crest dimensions in esthetic single implant sites after a 5-to-9-year follow-up analyzed by cone beam computed tomography (CBCT). Sixty-one patients with an implant-borne single crown following early implant placement in the esthetic zone were enrolled. The test group consisted of a bone level (BL) neck design exhibiting a hydrophilic micro-rough surface combined with a platform-switching interface (PS) (n = 20). The control group comprised a soft tissue level (STL) neck design exhibiting a hydrophobic machined surface with a matching butt-joint interface (n = 41). Standardized clinical, radiologic, and esthetic parameters were applied. The facial bone crest dimensions were assessed by CBCT. Soft tissue parameters and pink esthetic scores yielded no significant differences between the two designs. Major differences were only observed at the implant shoulder level. The height of the facial bone crest for the BL design was located 0.2 mm above the implant shoulder level, whereas for the STL design, its location was 1.6 mm below. The width of the peri-implant saucer-like bone defect was reduced by 40% for the BL implant design. No differences were observed 2 mm below the shoulder level. The results of this comparative study suggest better crestal bone stability on the facial aspect of single implant sites in the esthetic zone for a BL design with a platform-switching concept when compared with STL implants with a butt-joint interface. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Extensor Tendon Instability Due to Sagittal Band Injury in a Martial Arts Athlete: A Case Report.

PubMed

Kochevar, Andrew; Rayan, Ghazi

2017-03-01

A Taekwondo participant sustained a hand injury from punching an opponent that resulted in painful instability of the ring finger extensor digitorum communis tendon due to sagittal band damage. His symptoms resolved after reconstructive surgery on the sagittal band (SB) with stabilization of the extensor tendon over the metacarpophalangeal joint.

In vivo measured joint friction in hip implants during walking after a short rest

PubMed Central

Damm, Philipp; Bender, Alwina; Duda, Georg; Bergmann, Georg

2017-01-01

Introduction It has been suspected that friction in hip implants is higher when walking is initiated after a resting period than during continuous movement. It cannot be excluded that such increased initial moments endanger the cup fixation in the acetabulum, overstress the taper connections in the implant or increase wear. To assess these risks, the contact forces, friction moments and friction coefficients in the joint were measured in vivo in ten subjects. Instrumented hip joint implants with telemetric data transmission were used to access the contact loads between the cup and head during the first steps of walking after a short rest. Results The analysis demonstrated that the contact force is not increased during the first step. The friction moment in the joint, however, is much higher during the first step than during continuous walking. The moment increases throughout the gait cycle were 32% to 143% on average and up to 621% individually. The high initial moments will probably not increase wear by much in the joint. However, comparisons with literature data on the fixation resistance of the cup against moments made clear that the stability can be endangered. This risk is highest during the first postoperative months for cementless cups with insufficient under-reaming. The high moments after a break can also put taper connections between the head and neck and neck and shaft at a higher risk. Discussion During continuous walking, the friction moments individually were extremely varied by factors of 4 to 10. Much of this difference is presumably caused by the varying lubrication properties of the synovia. These large moment variations can possibly lead to friction-induced temperature increases during walking, which are higher than the 43.1°C which have previously been observed in a group of only five subjects. PMID:28350858

Manufacturing conditioned roughness and wear of biomedical oxide ceramics for all-ceramic knee implants

PubMed Central

2013-01-01

Background Ceramic materials are used in a growing proportion of hip joint prostheses due to their wear resistance and biocompatibility properties. However, ceramics have not been applied successfully in total knee joint endoprostheses to date. One reason for this is that with strict surface quality requirements, there are significant challenges with regard to machining. High-toughness bioceramics can only be machined by grinding and polishing processes. The aim of this study was to develop an automated process chain for the manufacturing of an all-ceramic knee implant. Methods A five-axis machining process was developed for all-ceramic implant components. These components were used in an investigation of the influence of surface conformity on wear behavior under simplified knee joint motion. Results The implant components showed considerably reduced wear compared to conventional material combinations. Contact area resulting from a variety of component surface shapes, with a variety of levels of surface conformity, greatly influenced wear rate. Conclusions It is possible to realize an all-ceramic knee endoprosthesis device, with a precise and affordable manufacturing process. The shape accuracy of the component surfaces, as specified by the design and achieved during the manufacturing process, has a substantial influence on the wear behavior of the prosthesis. This result, if corroborated by results with a greater sample size, is likely to influence the design parameters of such devices. PMID:23988155

Manufacturing conditioned roughness and wear of biomedical oxide ceramics for all-ceramic knee implants.

PubMed

Turger, Anke; Köhler, Jens; Denkena, Berend; Correa, Tomas A; Becher, Christoph; Hurschler, Christof

2013-08-29

Ceramic materials are used in a growing proportion of hip joint prostheses due to their wear resistance and biocompatibility properties. However, ceramics have not been applied successfully in total knee joint endoprostheses to date. One reason for this is that with strict surface quality requirements, there are significant challenges with regard to machining. High-toughness bioceramics can only be machined by grinding and polishing processes. The aim of this study was to develop an automated process chain for the manufacturing of an all-ceramic knee implant. A five-axis machining process was developed for all-ceramic implant components. These components were used in an investigation of the influence of surface conformity on wear behavior under simplified knee joint motion. The implant components showed considerably reduced wear compared to conventional material combinations. Contact area resulting from a variety of component surface shapes, with a variety of levels of surface conformity, greatly influenced wear rate. It is possible to realize an all-ceramic knee endoprosthesis device, with a precise and affordable manufacturing process. The shape accuracy of the component surfaces, as specified by the design and achieved during the manufacturing process, has a substantial influence on the wear behavior of the prosthesis. This result, if corroborated by results with a greater sample size, is likely to influence the design parameters of such devices.

Conformational Changes in the Carpus During Finger Traps Distraction

PubMed Central

Leventhal, Evan L.; Moore, Douglas C.; Akelman, Edward; Wolfe, Scott W.; Crisco, Joseph J.

2010-01-01

Introduction Wrist distraction is a common treatment maneuver used clinically for the reduction of distal radial fractures and mid-carpal dislocations. Wrist distraction is also required during wrist arthroscopy to access the radiocarpal joint and has been used as a test for scapholunate ligament injury. However, the effect of a distraction load on the normal wrist has not been well studied. The purpose of this study was to measure the 3-D conformational changes of the carpal bones in the normal wrist as a result of a static distractive load. Methods The dominant wrists of 14 healthy volunteers were scanned using computed tomography at rest and during application of 98N of distraction. Load was applied using finger traps and volunteers were encouraged to relax their forearm muscles and to allow distraction of the wrist. The motions of the bones in the wrist were tracked between the unloaded and loaded trial using markerless bone registration. The average displacement vector of each bone was calculated relative to the radius as well as the interbone distances for 20 bone-bone interactions. Joint separation was estimated at the radiocarpal, midcarpal and carpal-metacarpal joints in the direction of loading using the radius, lunate, capitate and 3rd metacarpal. Results With loading, the distance between the radius and 3rd metacarpal increased an average of 3.3±3.1mm in the direction of loading. This separation was primarily located in the axial direction at the radiocarpal (1.0±1.0mm) and midcarpal (2.0±1.7mm) joints. There were minimal changes in the transverse direction within the distal row, although the proximal row narrowed by 0.98±0.7mm. Distraction between the radius and scaphoid (2.5±2.2mm) was 2.4 times greater than between the radius and lunate (1.0±1.0mm). Conclusions Carpal distraction has a significant effect on the conformation of the carpus, especially at the radiocarpal and midcarpal joints. In the normal wrist, external traction causes twice as much distraction at the lunocapitate joint than at the radiolunate joint. PMID:20141894

Conformational changes in the carpus during finger trap distraction.

PubMed

Leventhal, Evan L; Moore, Douglas C; Akelman, Edward; Wolfe, Scott W; Crisco, Joseph J

2010-02-01

Wrist distraction is a common treatment maneuver used clinically for the reduction of distal radial fractures and midcarpal dislocations. Wrist distraction is also required during wrist arthroscopy to access the radiocarpal joint and has been used as a test for scapholunate ligament injury. However, the effect of a distraction load on the normal wrist has not been well studied. The purpose of this study was to measure the three-dimensional conformational changes of the carpal bones in the normal wrist as a result of a static distractive load. Using computed tomography, the dominant wrists of 14 healthy volunteers were scanned at rest and during application of 98 N of distraction. Load was applied using finger traps, and volunteers were encouraged to relax their forearm muscles and to allow distraction of the wrist. The motions of the bones in the wrist were tracked between the unloaded and loaded trial using markerless bone registration. The average displacement vector of each bone relative to the radius was calculated, as were the interbone distances for 20 bone-bone interactions. Joint separation was estimated at the radiocarpal, midcarpal, and carpometacarpal joints in the direction of loading using the radius, lunate, capitate, and third metacarpal. With loading, the distance between the radius and third metacarpal increased an average of 3.3 mm +/- 3.1 in the direction of loading. This separation was primarily in the axial direction at the radiocarpal (1.0 mm +/- 1.0) and midcarpal (2.0 mm +/- 1.7) joints. There were minimal changes in the transverse direction within the distal row, although the proximal row narrowed by 0.98 mm +/- 0.7. Distraction between the radius and scaphoid (2.5 mm +/- 2.2) was 2.4 times greater than that between the radius and lunate (1.0 mm +/- 1.0). Carpal distraction has a significant (p < .01) effect on the conformation of the carpus, especially at the radiocarpal and midcarpal joints. In the normal wrist, external traction causes twice as much distraction at the lunocapitate joint than at the radiolunate joint. Copyright 2010. Published by Elsevier Inc.

Amplification, Technology, and Cochlear Implants for Infants.

ERIC Educational Resources Information Center

Adam, Arlie J.

1993-01-01

Early amplification is crucial to efficient habilitation and development of oral communication skills in hearing-impaired infants. Initial evaluation and fitting of amplification is a joint effort by the audiologist, therapist, and parents, whether the child uses traditional hearing aids or cochlear implants, and should be supplemented by a…

Why borrow from Peter when Paul can afford it? Reverse homodigital artery flap for fingertip reconstruction

PubMed Central

Sundaramurthy, Narayanamurthy; Venkata Mahipathy, Surya Rao Rao; Durairaj, Alagar Raja

2017-01-01

Background: Fingertip injuries that are complicated by pulp loss, bone or tendon exposure will need a flap cover. Cross finger flap is commonly used to cover such defects. However, patients are apprehensive about injuring the uninjured finger as a donor site. Reverse homodigital artery flap (RHAF) can provide reliable vascularised cover to such defects. Aims: This study aims to assess the functional and aesthetic outcomes along with the patient satisfaction of RHAFs done for fingertip defects. Materials and Methods: RHAFs done in 18 patients operated between August 2015 and October 2016 were retrospectively analysed on flap survival, sensory recovery, range of movements, hypersensitivity, cold intolerance, flexion contracture and donor site morbidity. Results: Seventeen of the 18 flaps done survived completely. One flap had partial necrosis of 3 mm that healed conservatively. Middle finger of the right hand was the most commonly injured finger. Touch, pain and pressure sensations recovered in 8–12 weeks. Two-point discrimination was 4.5 mm at 6 months. The deficit of 5° s was present at distal interphalangeal joint during active flexion at 6 months. Cold intolerance and flexion contracture were not seen and 2 instances of hypersensitivity at 2 months got cured conservatively after 4 months. Overall satisfaction of patients was 8/10. Conclusion: RHAF provides single staged well-vascularised cover for fingertip injuries with good sensory recovery without damaging the adjacent uninjured finger. Hence, it can be a reliable flap for fingertip reconstruction in selected cases. PMID:29343895

In vivo axial humero-ulnar rotation in normal and dysplastic canine elbow joints.

PubMed

Rohwedder, Thomas; Fischer, Martin; Böttcher, Peter

2018-04-01

To prospectively compare relative axial (internal-external) humero-ulnar rotation in normal and dysplastic canine elbow joints. Six normal elbows (five dogs) and seven joints (six dogs) with coronoid disease were examined. After implantation of 0.8 mm tantalum beads into humerus and ulna, biplanar x-ray movies of the implanted elbows were taken while dogs were walking on a treadmill. Based on the 2D bead coordinates of the synchronized x-ray movies virtual 3D humero-ulnar animations were calculated. Based on these, relative internal-external humero-ulnar rotation was measured over the first third of stance phase and expressed as maximal rotational amplitude. Amplitudes from three consecutive steps were averaged and groupwise compared using an unpaired t-test. In normal elbow joints mean axial relative humero-ulnar rotation was 2.9° (SD 1.1). Dysplastic joints showed a significantly greater rotational amplitude (5.3°, SD 2.0; p = 0.0229, 95% confidence interval 0.4-4.4). Dysplastic elbow joints show greater relative internal-external humero-ulnar rotation compared to normal elbows, which might reflect rotational joint instability. Increased relative internal-external humero-ulnar rotation might alter physiological joint contact and pressure patterns. Future studies are needed to verify if this plays a role in the pathogenesis of medial coronoid disease. Schattauer GmbH.

Sinking and fit of abutment of locking taper implant system

PubMed Central

Moon, Seung-Jin; Kim, Hee-Jung; Son, Mee-Kyoung

2009-01-01

STATEMENT OF PROBLEM Unlike screw-retention type, fixture-abutment retention in Locking taper connection depends on frictional force so it has possibility of abutment to sink. PURPOSE In this study, Bicon® Implant System, one of the conical internal connection implant system, was used with applying loading force to the abutments connected to the fixture. Then the amount of sinking was measured. MATERIAL AND METHODS 10 Bicon® implant fixtures were used. First, the abutment was connected to the fixture with finger force. Then it was tapped with a mallet for 3 times and loads of 20 kg corresponding to masticatory force using loading application instrument were applied successively. The abutment state, slightly connected to the fixture without pressure was considered as a reference length, and every new abutment length was measured after each load's step was added. The amount of abutment sinking (mm) was gained by subtracting the length of abutment-fixture under each loading condition from reference length. RESULTS It was evident, that the amount of abutment sinking in Bicon® Implant System increased as loads were added. When loads of 20 kg were applied more than 5 - 7 times, sinking stopped at 0.45 ± 0.09 mm. CONCLUSION Even though locking taper connection type implant shows good adaption to occlusal force, it has potential for abutment sinking as loads are given. When locking taper connection type implant is used, satisfactory loads are recommended for precise abutment location. PMID:21165262

Durable engraftment of genetically modified FVIII-secreting autologous bone marrow stromal cells in the intramedullary microenvironment.

PubMed

Lee, Sze Sing; Sivalingam, Jaichandran; Nirmal, Ajit J; Ng, Wai Har; Kee, Irene; Song, In Chin; Kiong, Chin Yong; Gales, Kristoffer A; Chua, Frederic; Pena, Edgar M; Ogden, Bryan E; Kon, Oi Lian

2018-04-23

Genetically modified FVIII-expressing autologous bone marrow-derived mesenchymal stromal cells (BMSCs) could cure haemophilia A. However, culture-expanded BMSCs engraft poorly in extramedullary sites. Here, we compared the intramedullary cavity, skeletal muscle, subcutaneous tissue and systemic circulation as tissue microenvironments that could support durable engraftment of FVIII-secreting BMSC in vivo. A zinc finger nuclease integrated human FVIII transgene into PPP1R12C (intron 1) of culture-expanded primary canine BMSCs. FVIII-secretory capacity of implanted BMSCs in each dog was expressed as an individualized therapy index (number of viable BMSCs implanted × FVIII activity secreted/million BMSCs/24 hours). Plasma samples before and after implantation were assayed for transgenic FVIII protein using an anti-human FVIII antibody having negligible cross-reactivity with canine FVIII. Plasma transgenic FVIII persisted for at least 48 weeks after implantation in the intramedullary cavity. Transgenic FVIII protein levels were low after intramuscular implantation and undetectable after both intravenous infusion and subcutaneous implantation. All plasma samples were negative for anti-human FVIII antibodies. Plasma concentrations and durability of transgenic FVIII secretion showed no correlation with the therapy index. Thus, the implantation site microenvironment is crucial. The intramedullary microenvironment, but not extramedullary tissues, supported durable engraftment of genetically modified autologous FVIII-secreting BMSCs. © 2018 National Cancer Centre of Singapore Pte Ltd. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

The Measurement Of Total Joint Loosening By X-Ray Photogrammetry

NASA Astrophysics Data System (ADS)

Lippert, Frederick G.; Veress, Sandor A.; Tiwari, Rama S.; Harrington, Richard M.

1980-07-01

Failure of total joint replacement due to loosening of the composents either between the implant and cement or between the cement and bone is emerging as a late complication with an incidence as high as 20 percent. Loosening may not only cause pain but progressive loss of support for the prosthesis with eventual structural failure. Early diagnosis is important so that revision may be carried when deterioration or pain occurs. No method is currently available which clearly establishes loosening at an early stage except surgical exploration. We have devised a method based on our in vivo photogrammetry studies of patellar tracking patterns using metallic markers placed in bone near both components of the total joint. Stereo x-rays taken with the joint loaded and unloaded are measured for relative motion between the implant and the metallic markers. Laboratory studies using prosthetic hip components mounted in plastic bone have revealed the ability of this method to detect pistoning movements as small as 80 microns. These findings were confirmed by physical measurements.

A muscle-driven approach to restore stepping with an exoskeleton for individuals with paraplegia.

PubMed

Chang, Sarah R; Nandor, Mark J; Li, Lu; Kobetic, Rudi; Foglyano, Kevin M; Schnellenberger, John R; Audu, Musa L; Pinault, Gilles; Quinn, Roger D; Triolo, Ronald J

2017-05-30

Functional neuromuscular stimulation, lower limb orthosis, powered lower limb exoskeleton, and hybrid neuroprosthesis (HNP) technologies can restore stepping in individuals with paraplegia due to spinal cord injury (SCI). However, a self-contained muscle-driven controllable exoskeleton approach based on an implanted neural stimulator to restore walking has not been previously demonstrated, which could potentially result in system use outside the laboratory and viable for long term use or clinical testing. In this work, we designed and evaluated an untethered muscle-driven controllable exoskeleton to restore stepping in three individuals with paralysis from SCI. The self-contained HNP combined neural stimulation to activate the paralyzed muscles and generate joint torques for limb movements with a controllable lower limb exoskeleton to stabilize and support the user. An onboard controller processed exoskeleton sensor signals, determined appropriate exoskeletal constraints and stimulation commands for a finite state machine (FSM), and transmitted data over Bluetooth to an off-board computer for real-time monitoring and data recording. The FSM coordinated stimulation and exoskeletal constraints to enable functions, selected with a wireless finger switch user interface, for standing up, standing, stepping, or sitting down. In the stepping function, the FSM used a sensor-based gait event detector to determine transitions between gait phases of double stance, early swing, late swing, and weight acceptance. The HNP restored stepping in three individuals with motor complete paralysis due to SCI. The controller appropriately coordinated stimulation and exoskeletal constraints using the sensor-based FSM for subjects with different stimulation systems. The average range of motion at hip and knee joints during walking were 8.5°-20.8° and 14.0°-43.6°, respectively. Walking speeds varied from 0.03 to 0.06 m/s, and cadences from 10 to 20 steps/min. A self-contained muscle-driven exoskeleton was a feasible intervention to restore stepping in individuals with paraplegia due to SCI. The untethered hybrid system was capable of adjusting to different individuals' needs to appropriately coordinate exoskeletal constraints with muscle activation using a sensor-driven FSM for stepping. Further improvements for out-of-the-laboratory use should include implantation of plantar flexor muscles to improve walking speed and power assist as needed at the hips and knees to maintain walking as muscles fatigue.

Biotribology of artificial hip joints

PubMed Central

Di Puccio, Francesca; Mattei, Lorenza

2015-01-01

Hip arthroplasty can be considered one of the major successes of orthopedic surgery, with more than 350000 replacements performed every year in the United States with a constantly increasing rate. The main limitations to the lifespan of these devices are due to tribological aspects, in particular the wear of mating surfaces, which implies a loss of matter and modification of surface geometry. However, wear is a complex phenomenon, also involving lubrication and friction. The present paper deals with the tribological performance of hip implants and is organized in to three main sections. Firstly, the basic elements of tribology are presented, from contact mechanics of ball-in-socket joints to ultra high molecular weight polyethylene wear laws. Some fundamental equations are also reported, with the aim of providing the reader with some simple tools for tribological investigations. In the second section, the focus moves to artificial hip joints, defining materials and geometrical properties and discussing their friction, lubrication and wear characteristics. In particular, the features of different couplings, from metal-on-plastic to metal-on-metal and ceramic-on-ceramic, are discussed as well as the role of the head radius and clearance. How friction, lubrication and wear are interconnected and most of all how they are specific for each loading and kinematic condition is highlighted. Thus, the significant differences in patients and their lifestyles account for the high dispersion of clinical data. Furthermore, such consideration has raised a new discussion on the most suitable in vitro tests for hip implants as simplified gait cycles can be too far from effective implant working conditions. In the third section, the trends of hip implants in the years from 2003 to 2012 provided by the National Joint Registry of England, Wales and Northern Ireland are summarized and commented on in a discussion. PMID:25621213

Design-validation of a hand exoskeleton using musculoskeletal modeling.

PubMed

Hansen, Clint; Gosselin, Florian; Ben Mansour, Khalil; Devos, Pierre; Marin, Frederic

2018-04-01

Exoskeletons are progressively reaching homes and workplaces, allowing interaction with virtual environments, remote control of robots, or assisting human operators in carrying heavy loads. Their design is however still a challenge as these robots, being mechanically linked to the operators who wear them, have to meet ergonomic constraints besides usual robotic requirements in terms of workspace, speed, or efforts. They have in particular to fit the anthropometry and mobility of their users. This traditionally results in numerous prototypes which are progressively fitted to each individual person. In this paper, we propose instead to validate the design of a hand exoskeleton in a fully digital environment, without the need for a physical prototype. The purpose of this study is thus to examine whether finger kinematics are altered when using a given hand exoskeleton. Therefore, user specific musculoskeletal models were created and driven by a motion capture system to evaluate the fingers' joint kinematics when performing two industrial related tasks. The kinematic chain of the exoskeleton was added to the musculoskeletal models and its compliance with the hand movements was evaluated. Our results show that the proposed exoskeleton design does not influence fingers' joints angles, the coefficient of determination between the model with and without exoskeleton being consistently high (R 2 ¯=0.93) and the nRMSE consistently low (nRMSE¯ = 5.42°). These results are promising and this approach combining musculoskeletal and robotic modeling driven by motion capture data could be a key factor in the ergonomics validation of the design of orthotic devices and exoskeletons prior to manufacturing. Copyright © 2017 Elsevier Ltd. All rights reserved.

Advances in Patellofemoral Arthroplasty.

PubMed

Strickland, Sabrina M; Bird, Mackenzie L; Christ, Alexander B

2018-06-01

To describe current indications, implants, economic benefits, comparison to TKA, and functional and patient-reported outcomes of patellofemoral arthroplasty. Modern onlay implants and improved patient selection have allowed for recent improvements in short- and long-term outcomes after patellofemoral joint replacement surgery. Patellofemoral arthroplasty has become an increasingly utilized technique for the successful treatment of isolated patellofemoral arthritis. Advances in patient selection, implant design, and surgical technique have resulted in improved performance and longevity of these implants. Although short- and mid-term data for modern patellofemoral arthroplasties appear promising, further long-term clinical studies are needed to evaluate how new designs and technologies will affect patient outcomes and long-term implant performance.

Nikolaus Rüdinger (1832-1896), His Description of Joint Innervation in 1857, and the History of Surgical Joint Denervation.

PubMed

Gohritz, Andreas; Kaiser, Erich; Guggenheim, Merlin; Dellon, Arnold Lee

2018-01-01

 Selective joint denervation has become a reliable palliative treatment, especially for painful joints in the upper and lower extremity.  This article highlights the life and work of Nikolaus Rüdinger (1832-1896) who first described joint innervation which became the basis of later techniques of surgical joint denervation. The historical evolution of this method is outlined.  Rüdinger made a unique career from apprentice barber to military surgeon and anatomy professor in Munich, Germany. His first description of articular innervation of temporomandibular, shoulder, elbow, wrist, finger, sacroiliac, hip, knee, ankle, foot, and toe joints in 1857 stimulated the subsequent history of surgical joint denervation. Comparing his investigations with modern joint denervation methods, developed by pioneers like Albrecht Wilhelm or A. Lee Dellon, shows his great exactitude and anatomical correspondence despite different current terminology. Clinical series of modern surgical joint denervations reveal success rates of up to 80% with reliable long-term results.  The history of joint denervation with Rüdinger as its important protagonist offers inspiring insights into the evolution of surgical techniques and exemplifies the value of descriptive functional anatomy, even if surgical application may not have been realized until a century later. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Biomechanics of unilateral and bilateral sacroiliac joint stabilization: laboratory investigation.

PubMed

Lindsey, Derek P; Parrish, Robin; Gundanna, Mukund; Leasure, Jeremi; Yerby, Scott A; Kondrashov, Dimitriy

2018-03-01

OBJECTIVE Bilateral symptoms have been reported in 8%-35% of patients with sacroiliac (SI) joint dysfunction. Stabilization of a single SI joint may significantly alter the stresses on the contralateral SI joint. If the contralateral SI joint stresses are significantly increased, degeneration may occur; alternatively, if the stresses are significantly reduced, bilateral stabilization may be unnecessary for patients with bilateral symptoms. The biomechanical effects of 1) unilateral stabilization on the contralateral SI joint and 2) bilateral stabilization on both SI joints are currently unknown. The objectives of this study were to characterize bilateral SI joint range of motion (ROM) and evaluate and compare the biomechanical effects of unilateral and bilateral implant placement for SI joint fusion. METHODS A lumbopelvic model (L5-pelvis) was used to test the ROM of both SI joints in 8 cadavers. A single-leg stance setup was used to load the lumbar spine and measure the ROM of each SI joint in flexion-extension, lateral bending, and axial rotation. Both joints were tested 1) while intact, 2) after unilateral stabilization, and 3) after bilateral stabilization. Stabilization consisted of lateral transiliac placement of 3 triangular titanium plasma-sprayed (TPS) implants. RESULTS Intact testing showed that during single-leg stance the contralateral SI joint had less ROM in flexion-extension (27%), lateral bending (32%), and axial rotation (69%) than the loaded joint. Unilateral stabilization resulted in significant reduction of flexion-extension ROM (46%) on the treated side; no significant ROM changes were observed for the nontreated side. Bilateral stabilization resulted in significant reduction of flexion-extension ROM of the primary (45%) and secondary (75%) SI joints. CONCLUSIONS This study demonstrated that during single-leg loading the ROMs for the stance (loaded) and swing (unloaded) SI joints are significantly different. Unilateral stabilization for SI joint dysfunction significantly reduces the ROM of the treated side, but does not significantly reduce the ROM of the nontreated contralateral SI joint. Bilateral stabilization is necessary to significantly reduce the ROM for both SI joints.

Laser Fabrication and Characterization of Adhesive-Free Joints for Encapsulation of Biomedical Implant Devices

DTIC Science & Technology

2005-01-01

excitation sources should be helpful in overcoming this problem. CONCLUSIONS Biocompatible joints between polyimide and titanium-coated borosilicate...Technology, 46025 Port St., Plymouth, MI 48170, U.S.A. ABSTRACT Laser-fabricated joints of sub-millimeter widths between biocompatible , dissimilar materials...method of a very promising system, polyimide /titanium-coated borosilicate glass, and present and discuss results from characterization of such laser

Joint angle sensors for closed-loop control

NASA Astrophysics Data System (ADS)

Ko, Wen H.; Miao, Chih-Lei

In order to substitute braces that have built-in goniometers and to provide feedback signals for closed loop control of lower extremity Functional Neuromuscular System in paraplegics, a stretchable capacitive sensor was developed to accurately detect angular movement in joints. Promising clinical evaluations on the knee joints of a paraplegic and a volunteer were done. The evaluations show great promise for the possibility of implantation applications.

Multifunctional Coatings to Simultaneously Promote Osseointegration and Prevent Infection of Orthopaedic Implants

PubMed Central

Raphel, Jordan; Holodniy, Mark; Goodman, Stuart B.; Heilshorn, Sarah C.

2016-01-01

The two leading causes of failure for joint arthroplasty prostheses are aseptic loosening and periprosthetic joint infection. With the number of primary and revision joint replacement surgeries on the rise, strategies to mitigate these failure modes have become increasingly important. Much of the recent work in this field has focused on the design of coatings either to prevent infection while ignoring bone mineralization or vice versa, to promote osseointegration while ignoring microbial susceptibility. However, both coating functions are required to achieve long-term success of the implant; therefore, these two modalities must be evaluated in parallel during the development of new orthopaedic coating strategies. In this review, we discuss recent progress and future directions for the design of multifunctional orthopaedic coatings that can inhibit microbial cells while still promoting osseointegration. PMID:26851394

Tribochemical Characterization and Tribocorrosive Behavior of CoCrMo Alloys: A Review

PubMed Central

Toh, Wei Quan; Liu, Erjia; Tor, Shu Beng

2017-01-01

Orthopedic implants first started out as an all-metal hip joint replacement. However, poor design and machinability as well as unsatisfactory surface finish subjected the all-metal joint replacement to being superseded by a polyethylene bearing. Continued improvement in manufacturing techniques together with the reality that polyethylene wear debris can cause hazardous reactions in the human body has brought about the revival of metal-on-metal (MOM) hip joints in recent years. This has also led to a relatively new research area that links tribology and corrosion together. This article aims at reviewing the commonly used tribochemical methods adopted in the analysis of tribocorrosion and putting forward some of the models and environmental factors affecting the tribocorrosive behavior of CoCrMo alloys, a widely-used class of biomaterial for orthopedic implants. PMID:29278375

Tribochemical Characterization and Tribocorrosive Behavior of CoCrMo Alloys: A Review.

PubMed

Toh, Wei Quan; Tan, Xipeng; Bhowmik, Ayan; Liu, Erjia; Tor, Shu Beng

2017-12-26

Orthopedic implants first started out as an all-metal hip joint replacement. However, poor design and machinability as well as unsatisfactory surface finish subjected the all-metal joint replacement to being superseded by a polyethylene bearing. Continued improvement in manufacturing techniques together with the reality that polyethylene wear debris can cause hazardous reactions in the human body has brought about the revival of metal-on-metal (MOM) hip joints in recent years. This has also led to a relatively new research area that links tribology and corrosion together. This article aims at reviewing the commonly used tribochemical methods adopted in the analysis of tribocorrosion and putting forward some of the models and environmental factors affecting the tribocorrosive behavior of CoCrMo alloys, a widely-used class of biomaterial for orthopedic implants.

Dynamic optical imaging of vascular and metabolic reactivity in rheumatoid joints.

PubMed

Lasker, Joseph M; Fong, Christopher J; Ginat, Daniel T; Dwyer, Edward; Hielscher, Andreas H

2007-01-01

Dynamic optical imaging is increasingly applied to clinically relevant areas such as brain and cancer imaging. In this approach, some external stimulus is applied and changes in relevant physiological parameters (e.g., oxy- or deoxyhemoglobin concentrations) are determined. The advantage of this approach is that the prestimulus state can be used as a reference or baseline against which the changes can be calibrated. Here we present the first application of this method to the problem of characterizing joint diseases, especially effects of rheumatoid arthritis (RA) in the proximal interphalangeal finger joints. Using a dual-wavelength tomographic imaging system together with previously implemented model-based iterative image reconstruction schemes, we have performed initial dynamic imaging case studies on a limited number of healthy volunteers and patients diagnosed with RA. Focusing on three cases studies, we illustrated our major finds. These studies support our hypothesis that differences in the vascular reactivity exist between affected and unaffected joints.

Protective effect of sensory denervation in inflammatory arthritis (evidence of regulatory neuroimmune pathways in the arthritic joint)

PubMed Central

Kane, D; Lockhart, J; Balint, P; Mann, C; Ferrell, W; McInnes, I

2005-01-01

Case report: The patient developed arthritis mutilans in all digits of both hands with the exception of the left 4th finger, which had prior sensory denervation following traumatic nerve dissection. Plain radiography, ultrasonography and nerve conduction studies of the hands confirmed the absence of articular disease and sensory innervation in the left 4th digit. Methods: This relationship between joint innervation and joint inflammation was investigated experimentally by prior surgical sensory denervation of the medial aspect of the knee in six Wistar rats in which carrageenan induced arthritis was subsequently induced. Prior sensory denervation—with preservation of muscle function—prevented the development of inflammatory arthritis in the denervated knee. Discussion: Observations in human and animal inflammatory arthritis suggest that regulatory neuroimmune pathways in the joint are an important mechanism that modulates the clinical expression of inflammatory arthritis. PMID:15155371

Electro-mechanical heat switch for cryogenic applications

DOEpatents

van den Berg, Marcel L.; Batteux, Jan D.; Labov, Simon E.

2003-01-01

A heat switch includes two symmetric jaws. Each jaw is comprised of a link connected at a translatable joint to a flexible arm. Each arm rotates about a fixed pivot, and has an articulated end including a thermal contact pad connected to a heat sink. The links are joined together at a translatable main joint. To close the heat switch, a closing solenoid is actuated and forces the main joint to an over-center position. This movement rotates the arms about their pivots, respectively, forces each of them into a stressed configuration, and forces the thermal contact pads towards each other and into compressive contact with a cold finger. The closing solenoid is then deactivated. The heat switch remains closed due to a restoring force generated by the stressed configuration of each arm, until actuation of an opening solenoid returns the main joint to its starting open-switch position.

In-game Management of Common Joint Dislocations

PubMed Central

Skelley, Nathan W.; McCormick, Jeremy J.; Smith, Matthew V.

2014-01-01

Context: Sideline management of sports-related joint dislocations often places the treating medical professional in a challenging position. These injuries frequently require prompt evaluation, diagnosis, reduction, and postreduction management before they can be evaluated at a medical facility. Our objective is to review the mechanism, evaluation, reduction, and postreduction management of sports-related dislocations to the shoulder, elbow, finger, knee, patella, and ankle joints. Evidence Acquisition: A literature review was performed using the PubMed database to evaluate previous and current publications focused on joint dislocations. This review focused on articles published between 1980 and 2013. Study Design: Clinical review. Level of Evidence: Level 4. Results: The clinician should weigh the benefits and risks of on-field reduction based on their knowledge of the injury and the presence of associated injuries. Conclusion: When properly evaluated and diagnosed, most sports-related dislocations can be reduced and initially managed at the game. PMID:24790695

The Pathology of Orthopedic Implant Failure Is Mediated by Innate Immune System Cytokines

PubMed Central

Landgraeber, Stefan; Jäger, Marcus; Jacobs, Joshua J.; Hallab, Nadim James

2014-01-01

All of the over 1 million total joint replacements implanted in the US each year are expected to eventually fail after 15–25 years of use, due to slow progressive subtle inflammation at the bone implant interface. This inflammatory disease state is caused by implant debris acting, primarily, on innate immune cells, that is, macrophages. This slow progressive pathological bone loss or “aseptic loosening” is a potentially life-threatening condition due to the serious complications in older people (>75 yrs) of total joint replacement revision surgery. In some people implant debris (particles and ions from metals) can influence the adaptive immune system as well, giving rise to the concept of metal sensitivity. However, a consensus of studies agrees that the dominant form of this response is due to innate reactivity by macrophages to implant debris where both danger (DAMP) and pathogen (PAMP) signalling elicit cytokine-based inflammatory responses. This paper discusses implant debris induced release of the cytokines and chemokines due to activation of the innate (and the adaptive) immune system and the subsequent formation of osteolysis. Different mechanisms of implant-debris reactivity related to the innate immune system are detailed, for example, danger signalling (e.g., IL-1β, IL-18, IL-33, etc.), toll-like receptor activation (e.g., IL-6, TNF-α, etc.), apoptosis (e.g., caspases 3–9), bone catabolism (e.g., TRAP5b), and hypoxia responses (Hif1-α). Cytokine-based clinical and basic science studies are in progress to provide diagnosis and therapeutic intervention strategies. PMID:24891761

[Application of distal palm perforator mini-flap in repair of scar contracture of digital web-spaces].

PubMed

Zhou, Xiao; Xu, Yajun; Rui, Yongjun; Shou, Kuishui; Yao, Qun

2011-02-01

To discuss the effectiveness of distal palm perforator mini-flap in the treatment of scar contracture of digital web-spaces. Between August 2008 and March 2010, 6 cases of scar contracture of digital web-spaces were treated, including 4 males and 2 females and aging 16-68 years (mean, 45 years). The causes were burn injury, twisting injury, and crush injury in 2 cases, respectively. The disease duration was from 3 months to 3 years. The affected digital web-spaces were from index finger to middle finger in 2 cases, from middle finger to ring finger in 3 cases, and from ring finger to small finger in 1 case. The maximum abduction degree of digital web-spaces was 5-10 degrees. The sizes and the depths of reshape of digital web-spaces disappeared. The defect size ranged from 20 mm x 8 mm to 30 mm x 13 mm after opening digital web-spaces. The size of the distal palm perforator mini-flap ranged from 25 mm x 10 mm to 35 mm x 15 mm. The donor sites were sutured directly. All 6 flaps survived and got primary healing. Incisions at donor sites healed by first intention. All patients were followed up 6-12 months. The reconstructed digital web-spaces had good appearance and soft texture. The range of motion of metacarpophalangeal joint was normal. The sizes and the depths of reshape of digital web-spaces were similar to normal ones. The maximum abduction degree of digital web-spaces was 40-60 degrees. There was no scar contracture of incision of palm. The shape of flaps and function of the fingers were satisfactory after 6-12 months of follow-up. It is an ideal method to treat scar contracture of digital web-spaces with distal palm perforator mini-flap.

Biological Strategies for Improved Osseointegration and Osteoinduction of Porous Metal Orthopedic Implants

PubMed Central

Riester, Scott M.; Bonin, Carolina A.; Kremers, Hilal Maradit; Dudakovic, Amel; Kakar, Sanjeev; Cohen, Robert C.; Westendorf, Jennifer J.

2015-01-01

The biological interface between an orthopedic implant and the surrounding host tissue may have a dramatic effect upon clinical outcome. Desired effects include bony ingrowth (osseointegration), stimulation of osteogenesis (osteoinduction), increased vascularization, and improved mechanical stability. Implant loosening, fibrous encapsulation, corrosion, infection, and inflammation, as well as physical mismatch may have deleterious clinical effects. This is particularly true of implants used in the reconstruction of load-bearing synovial joints such as the knee, hip, and the shoulder. The surfaces of orthopedic implants have evolved from solid-smooth to roughened-coarse and most recently, to porous in an effort to create a three-dimensional architecture for bone apposition and osseointegration. Total joint surgeries are increasingly performed in younger individuals with a longer life expectancy, and therefore, the postimplantation lifespan of devices must increase commensurately. This review discusses advancements in biomaterials science and cell-based therapies that may further improve orthopedic success rates. We focus on material and biological properties of orthopedic implants fabricated from porous metal and highlight some relevant developments in stem-cell research. We posit that the ideal primary and revision orthopedic load-bearing metal implants are highly porous and may be chemically modified to induce stem cell growth and osteogenic differentiation, while minimizing inflammation and infection. We conclude that integration of new biological, chemical, and mechanical methods is likely to yield more effective strategies to control and modify the implant–bone interface and thereby improve long-term clinical outcomes. PMID:25348836

Laser welding and syncristallization techniques comparison: “Ex vivo” study

PubMed Central

Meleti, Marco; Vescovi, Paolo; Merigo, Elisabetta; Rocca, Jean-Paul

2013-01-01

Background and aims: Stabilization of implant abutments through electric impulses at high voltage for a very short time (electrowelding) was developed in the Eighties. In 2009, the same procedure was performed through the use of laser (laser welding) The aim of this study is to compare electrowelding and laser welding for intra-oral implant abutments stabilization on “ex vivo models” (pig jaws). Materials and methods: Six bars were welded with two different devices (Nd:YAG laser and Electrowelder) to eighteen titanium implant abutment inserted in three pig jaws. During the welding process, thermal increase was recorded, through the use of k-thermocouples, in the bone close to the implants. The strength of the welded joints was evaluated by a traction test after the removal of the implants. For temperature measurements a descriptive analysis and for traction test “values unpaired t test with Welch's correction” were performed: the significance level was set at P<0.05. Results: Laser welding gives a lower thermal increase than Electrowelding at the bone close to implants (Mean: 1.97 and 5.27); the strength of laser welded joints was higher than that of Electrowelding even if nor statistically significant. (Mean: 184.75 and 168.29) Conclusion: Electrowelding seems to have no advantages, in term of thermal elevation and strength, while laser welding may be employed to connect titanium implants for immediate load without risks of thermal damage at surrounding tissues. PMID:24511205

Influence of Four Different Abutment Materials and the Adhesive Joint of Two-Piece Abutments on Cervical Implant Bone and Soft Tissue.

PubMed

Mehl, Christian; Gassling, Volker; Schultz-Langerhans, Stephan; Açil, Yahya; Bähr, Telse; Wiltfang, Jörg; Kern, Matthias

The main aim of this study was to evaluate the influence of four different abutment materials and the adhesive joint of two-piece abutments on the cervical implant bone and soft tissue. Sixty-four titanium implants (Camlog Conelog; 4.3 ± 9 mm) were placed bone level into the edentulous arches of four minipigs. Four different types of abutments were placed at implant exposure: zirconium dioxide, lithium disilicate, and titanium bonded to a titanium luting base with resin cement; one-piece titanium abutments served as the control. The animals were sacrificed 6 months after implant exposure, and the bone-to-implant contact (BIC) area, sulcus depth, the length of the junctional epithelium and the connective tissue, the biologic width, and first cervical BIC-implant shoulder distance were measured using histomorphometry and light and fluorescence microscopy. Overall, 14 implants were lost (22%). At exposure, the implant shoulder-bone distance was 0.6 ± 0.7 mm. Six months later, the bone loss was 2.1 ± 1.2 mm measured histomorphometrically. There was a significant difference between the two measurements (P ≤ .0001). No significant influence could be found between any of the abutment materials with regard to bone loss or soft tissue anatomy (P > .05), with the exception of zirconium dioxide and onepiece titanium abutments when measuring the length of the junctional epithelium (P ≤ .01). The maxilla provided significantly more soft tissue and less bone loss compared with the mandible (P ≤ .02). All tested abutment materials and techniques seem to be comparable with regard to soft tissue properties and the cervical bone level.

Influence of the middle ear anatomy on the performance of a membrane sensor in the incudostapedial joint gap.

PubMed

Koch, Martin; Seidler, Hannes; Hellmuth, Alexander; Bornitz, Matthias; Lasurashvili, Nikoloz; Zahnert, Thomas

2013-07-01

There is a great demand for implantable microphones for future generations of implantable hearing aids, especially Cochlea Implants. An implantable middle ear microphone based on a piezoelectric membrane sensor for insertion into the incudostapedial gap is investigated. The sensor is designed to measure the sound-induced forces acting on the center of the membrane. The sensor mechanically couples to the adjacent ossicles via two contact areas, the sensor membrane and the sensor housing. The sensing element is a piezoelectric single crystal bonded on a titanium membrane. The sensor allows a minimally invasive and reversible implantation without removal of ossicles and without additional sensor fixation in the tympanic cavity. This study investigates the implantable microphone sensor and its implantation concept. It intends to quantify the influence of the sensor's insertion position on the achievable microphone sensitivity. The investigation considers anatomical and pathological variations of the middle ear geometry and its space limitations. Temporal bone experiments on a laboratory model show that anatomical and pathological variations of the middle ear geometry can prevent the sensor from being placed optimally within the incudostapedial joint. Beyond scattering of transfer functions due to anatomic variations of individual middle ears there is the impact of variations in the sensor position within the ossicular chain that has a considerable effect on the transfer characteristics of the middle ear microphone. The centering of the sensor between incus and stapes, the direction of insertion (membrane to stapes or to incus) and the effect of additional contact points with surrounding anatomic structures affect the signal yield of the implanted sensor. The presence of additional contact points has a considerably impact on the sensitivity, yet the microphone sensitivity is quite robust against small changes in the positioning of the incus on the sensor. Signal losses can be avoided by adjusting the position of the sensor within the joint. The findings allow the development of an improved surgical insertion technique to ensure maximally achievable signal yield of the membrane sensor in the ISJ and provides valuable knowledge for a future design considerations including sensor miniaturization and geometry. Measurements of the implanted sensor in temporal bone specimens showed a microphone sensitivity in the order of 1 mV/Pa. This article is part of a special issue entitled "MEMRO 2012". Copyright © 2012 Elsevier B.V. All rights reserved.

Fluorescence optical imaging and 3T-MRI for detection of synovitis in patients with rheumatoid arthritis in comparison to a composite standard of reference.

PubMed

Thuermel, Klaus; Neumann, Jan; Jungmann, Pia M; Schäffeler, Christoph; Waldt, Simone; Heinze, Alexander; Beckmann, Alexander; Hauser, Christine; Hasenau, Anna-Lena; Wildgruber, Moritz; Clotten, Sigrun; Sievert, Matti; Haller, Bernhard; Woertler, Klaus; Harasser, Norbert; Rummeny, Ernst J; Meier, Reinhard

2017-05-01

To address whether Indocyanine Green (ICG) enhanced fluorescence optical imaging (FOI) is more sensitive than magnetic resonance imaging (MRI) in the detection of synovitis of the wrist and finger joints in rheumatoid arthritis and to analyze the performance of FOI depending on the grade of synovitis. Twenty patients with highly active rheumatoid arthritis (mean DAS28-ESR 5.25±1.0) and thirteen healthy volunteers underwent clinical examination, FOI and contrast-enhanced 3T-MRI. Joints were rated by three independent readers semiquantitatively (grade 0-3: no, low, moderate and high grade synovitis) and compared to a semiquantitative composite standard of reference (cSOR, grade 0-3) that incorporated clinical parameters, FOI and MRI results. 2.868 evaluations in 956 joints were performed. FOI had an overall sensitivity of 57.3% and a specificity of 92.1%, whereas MRI had a sensitivity of 89.2% and a specificity of 92.6%. The sensitivity of FOI increased with the degree of synovitis to 65.0% for moderate and severe synovitis (specificity 88.1%) and 76,3% for severe synovitis (specificity 80.5%). The performance of FOI decreased with the degree of synovitis with false negative results predominantly for mild (156/343, 45.5%) and moderate (160/343, 46.6%) synovitis and false positive FOI evaluations predominantly based on weak (grade 1) signals (133/163, 81,6%). FOI has a lower sensitivity than 3T-MRI in the detection of synovitis of the hand and finger joints. The diagnostic performance of FOI decreases with the degree of synovitis and with the strength of FOI signals. Copyright © 2017 Elsevier B.V. All rights reserved.

Postural and Intention Tremors: A Detailed Clinical Study of Essential Tremor vs. Parkinson’s Disease

PubMed Central

Sternberg, Eliezer J.; Alcalay, Roy N.; Levy, Oren A.; Louis, Elan D.

2013-01-01

Background: An estimated 30–50% of essential tremor (ET) diagnoses are incorrect, and the true diagnosis in those patients is often Parkinson’s disease (PD) or other tremor disorders. There are general statements about the tremor in these ET and PD, but published data on the more subtle characteristics of tremor are surprisingly limited. Postural tremor may occur in both disorders, adding to the difficulty. There are several anecdotal impressions regarding specific features of postural tremor in ET vs. PD, including joint distribution (e.g., phalanges, metacarpal-phalangeal joints, wrist), tremor directionality (e.g., flexion-extension vs. pronation-supination), and presence of intention tremor. However, there is little data to support these impressions. Methods: In this cross-sectional study, 100 patients (ET, 50 PD) underwent detailed videotaped neurological examinations. Arm tremor was rated by a movement disorder neurologist who assessed severity and directionality across multiple joints. Results: During sustained arm extension, ET patients exhibited more wrist than metacarpal-phalangeal and phalangeal joint tremor than did PD patients (p < 0.001), and more wrist flexion-extension tremor than wrist pronation-supination tremor (p < 0.001). During the finger-nose-finger maneuver, intention tremor was present in approximately one in four (28%) ET patients vs. virtually none (4%) of the Parkinson’s patients (p < 0.001). Conclusions: We evaluated the location, severity, and directionality of postural tremor in ET and PD, and the presence of intention tremor, observing several clinical differences. We hope that detailed phenomenological data on tremor in ET and PD will help practicing physicians delineate the two diseases. PMID:23717300

The Neurological-Impress Method of Teaching Reading.

ERIC Educational Resources Information Center

Partridge, Susan

In the neurological impress method the teacher sits slightly behind the child, a book is held jointly, and the teacher and child read aloud simultaneously with the teacher directing his/her voice into the child's ear as the child slides a finger along each line following the words as they are spoken. No attempt is made to teach sounds or word…

21 CFR 888.3150 - Elbow joint metal/polymer constrained cemented prosthesis.

Code of Federal Regulations, 2010 CFR

2010-04-01

... use with bone cement (§ 888.3027). (b) Classification. Class II. The special controls for this device...) “Guidance Document for Testing Orthopedic Implants with Modified Metallic Surfaces Apposing Bone or Bone... Biomaterials (Nonporous) for Surgical Implant with Respect to Effect of Material on Muscle and Bone,” (v) F...

21 CFR 888.3150 - Elbow joint metal/polymer constrained cemented prosthesis.

Code of Federal Regulations, 2012 CFR

2012-04-01

... use with bone cement (§ 888.3027). (b) Classification. Class II. The special controls for this device...) “Guidance Document for Testing Orthopedic Implants with Modified Metallic Surfaces Apposing Bone or Bone... Biomaterials (Nonporous) for Surgical Implant with Respect to Effect of Material on Muscle and Bone,” (v) F...

21 CFR 888.3150 - Elbow joint metal/polymer constrained cemented prosthesis.

Code of Federal Regulations, 2014 CFR

2014-04-01

... use with bone cement (§ 888.3027). (b) Classification. Class II. The special controls for this device...) “Guidance Document for Testing Orthopedic Implants with Modified Metallic Surfaces Apposing Bone or Bone... Biomaterials (Nonporous) for Surgical Implant with Respect to Effect of Material on Muscle and Bone,” (v) F...