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1

CHONDROMALACIA OF THE PATELLA  

Microsoft Academic Search

Chondromalacia is a precursor of osteoarthritis. It can, perhaps, be regarded as an early senescence (the changes in the intervertebral discs that begin during the second decade of life are often so described) but much more must be learnt about the chemistry of proteins and polysaccharides before such an idea can be accepted. The articular cartilage of the patella is

P. S. ANDREWS; M. B. DEVAS

1956-01-01

2

Joint hypermobility in patients with chondromalacia patellae  

Microsoft Academic Search

SUMMARY The relationship between joint mobility and chondromalacia patellae was reported in a prospective study. A total of 115 patients with chondromalacia patellae were compared with 110 healthy individuals without chondromalacia patellae, matched for age and sex, who served as a control group. The degree of joint mobility was scored on a scale of 0-9. The number of individuals with

Z. AL-RAWI; A. H. NESSAN

1997-01-01

3

Chondromalacia Patellae: Diagnosis with MR Imaging  

Microsoft Academic Search

Most previous studies of MR imaging for detection of chondromalacia have used Ti- weighted images. We correlated findings on axial MR images of the knee with arthro- scopic findings to determine MR findings of chondromalacia patellae on T2-weighted and proton density-weighted images. The study population included 52 patients who had MR examination of the knee with a 15-T unit and

Thomas R. McCauley; Ruben Kier; Kevin J. Lynch; Peter Jokl

4

Thermography in the detection and follow up of chondromalacia patellae.  

PubMed Central

Although diagnostic criteria for chondromalacia patellae exist, the disease is often accompanied by physical signs which are limited or non-diagnostic. Thermographic examination was performed in 157 patients with clinical diagnosis of chondromalacia patellae in 86 patients after surgical treatment for chondromalacia, and in 308 controls. Thermography can help the clinicians in establishing the diagnosis of chondromalacia patellae, but by itself is not sufficiently specific. The specificity of thermography was dependent on age, ranging from 90% for the 15-24 year age group to 65% for the 45-54 year age group. Sensitivity of the method was 68%. Thermography can disclose other knee disorders which imitate chondromalacia patellae. Images PMID:1768161

Vujcic, M; Nedeljkovic, R

1991-01-01

5

Chondromalacia.  

ERIC Educational Resources Information Center

Chondromalacia is the degeneration of the hyaline cartilage on the under surface of the kneecap. Its causes include patella maltracking (the kneecap does not glide properly over the joint), posttraumatic condition, and chronic overuse. The treatment can be a controlled rehabilitation program, various bracing techniques, foot orthoses, or, in…

Connors, G. Patrick

6

A Novel Biological Approach to Treat Chondromalacia Patellae  

PubMed Central

Mesenchymal stem cells from several sources (bone marrow, synovial tissue, cord blood, and adipose tissue) can differentiate into variable parts (bones, cartilage, muscle, and adipose tissue), representing a promising new therapy in regenerative medicine. In animal models, mesenchymal stem cells have been used successfully to regenerate cartilage and bones. However, there have been no follow-up studies on humans treated with adipose-tissue-derived stem cells (ADSCs) for the chondromalacia patellae. To obtain ADSCs, lipoaspirates were obtained from lower abdominal subcutaneous adipose tissue. The stromal vascular fraction was separated from the lipoaspirates by centrifugation after treatment with collagenase. The stem-cell-containing stromal vascular fraction was mixed with calcium chloride-activated platelet rich plasma and hyaluronic acid, and this ADSCs mixture was then injected under ultrasonic guidance into the retro-patellar joints of all three patients. Patients were subjected to pre- and post-treatment magnetic resonance imaging (MRI) scans. Pre- and post-treatment subjective pain scores and physical therapy assessments measured clinical changes. One month after the injection of autologous ADSCs, each patient's pain improved 50–70%. Three months after the treatment, the patients' pain improved 80–90%. The pain improvement persisted over 1 year, confirmed by telephone follow ups. Also, all three patients did not report any serious side effects. The repeated magnetic resonance imaging scans at three months showed improvement of the damaged tissues (softened cartilages) on the patellae-femoral joints. In patients with chondromalacia patellae who have continuous anterior knee pain, percutaneous injection of autologous ADSCs may play an important role in the restoration of the damaged tissues (softened cartilages). Thus, ADSCs treatment presents a glimpse of a new promising, effective, safe, and non-surgical method of treatment for chondromalacia patellae. PMID:23700485

Lee, Sang Hee

2013-01-01

7

The modified tibial tubercle osteotomy for anterior knee pain due to chondromalacia patellae in adults  

PubMed Central

Objectives To assess the effectiveness of a modified tibial tubercle osteotomy as a treatment for arthroscopically diagnosed chondromalacia patellae. Methods A total of 47 consecutive patients (51 knees) with arthroscopically proven chondromalacia, who had failed conservative management, underwent a modified Fulkerson tibial tubercle osteotomy. The mean age was 34.4 years (19.6 to 52.2). Pre-operatively, none of the patients exhibited signs of patellar maltracking or instability in association with their anterior knee pain. The minimum follow-up for the study was five years (mean 72.6 months (62 to 118)), with only one patient lost to follow-up. Results A total of 50 knees were reviewed. At final follow-up, the Kujala knee score improved from 39.2 (12 to 63) pre-operatively to 57.7 (16 to 89) post-operatively (p < 0.001). The visual analogue pain score improved from 7.8 (4 to 10) pre-operatively to 5.0 (0 to 10) post-operatively. Overall patient satisfaction with good or excellent results was 72%. Patients with the lowest pre-operative Kujala score benefitted the most. Older patients benefited less than younger ones. The outcome was independent of the grade of chondromalacia. Six patients required screw removal. There were no major complications. Conclusions We conclude that this modification of the Fulkerson procedure is a safe and useful operation to treat anterior knee pain in well aligned patellofemoral joints due to chondromalacia patellae in adults, when conservative measures have failed. PMID:23610687

Jack, C. M.; Rajaratnam, S. S.; Khan, H. O.; Keast-Butler, O.; Butler-Manuel, P. A.; Heatley, F. W.

2012-01-01

8

Anterior Knee Pain (Chondromalacia Patellae).  

ERIC Educational Resources Information Center

This article presents a pragmatic approach to the definition, diagnosis, and management of anterior knee pain. Symptoms and treatment are described. Emphasis is on active involvement of the patient in the rehabilitation exercise program. (IAH)

Garrick, James G.

1989-01-01

9

Combined Proximal and Distal Realignment Procedures to Treat the Habitual Dislocation of the Patella in Adults  

Microsoft Academic Search

Background: Habitual dislocation of the patella (HDP) is a rare condition. Many surgical procedures using proximal realignment have been reported to treat HDP in children, with around 80% satisfactory results. However, few articles have addressed the treatment of HDP associated with high-grade patellofemoral chondromalacia in adults.Hypothesis: A combination of proximal and distal realignment procedures of the patella will reduce pain

Hsain-Chung Shen; Kuo-Hua Chao; Guo-Shu Huang; Ru-Yu Pan; Chian-Her Lee

2007-01-01

10

Excessive pronation: a major biomechanical determinant in the development of chondromalacia and pelvic lists.  

PubMed

Based on statistical analysis of 97 chronic low back patients, a pelvic list model has been proposed explaining the correlation between leg length discrepancies (LLD) and sciatica. This model suggests that asymmetrical pronation patterns (one pedal arch dropping more than the contralateral pedal arch) initiates a forward downward rotation within the sacroiliac joint. Entrapment of the sciatic nerve between the piriformis muscle and sacrospinous ligament occurs. Clinically, paresis is observed: numbness, weakness and eventually paralysis of the affected limb. Based on this work, the authors have comprised a classification dividing LLD into two main categories: functional and anatomical. Functional LLD have been subdivided into two types of lists: static and dynamic. Treatment based on a combination of chiropractic and podiatric therapy is presented with a 6-month follow-up. Analysis of the success in this tandem approach is very promising. Concurrently, a chondromalacia model is proposed explaining the pathomechanical events associated with oblique tracking patellar syndrome. The authors suggest that excessive pronation is the causative factor directing asynchronous rotation between the shank and femur. This forces the patella out of its normal tracking groove, which, in turn, generates erosion between the inferior margin of the patella and femoral epicondyles. PMID:2976805

Rothbart, B A; Estabrook, L

1988-10-01

11

The mouse patella assay  

Microsoft Academic Search

An easy method of quantitating articular cartilage chondrocyte function in mice is described, using a defined and anatomically intact cartilage structure, the patella. To avoid damage to the cartilage before incubation, 35S incorporation studies were performed leaving the patellae surrounded by a minimal area of non-cartilaginous connective tissue. The patellae were then punched out so that the 35S activity incorporated

W. B. van den Berg; M. W. M. Kruijsen

1982-01-01

12

[Patella dislocation in athletes].  

PubMed

Most dislocations of the patella occur during sports activities. The entities instability, maltracking and loss of tracking should be defined by patient history, clinical examination and radiological evaluation including magnetic resonance imaging (MRI). Based on these criteria a new classification of patella dislocations (5 types) was established which allows a standardized treatment algorithm. Type 1 is a simple (traumatic) dislocation without maltracking and without instability. Type 2 has a high redislocation risk (defined as instability) without maltracking. An isolated stabilizing surgical procedure, such as medial patellofemoral ligament (MPFL) augmentation is successful in most cases. Type 3 is characterized by instability and maltracking. Maltracking can be caused by soft tissue contracture or muscular deficits (type 3a), patella alta (type 3b), pathological tibial tuberosity to trochlear groove (TT-TG) distance (type 3c), genu valgum (type 3d) and torsional deformities (type 3e). In these types an isolated soft tissue procedure is usually not sufficient. The bony pathologies additionally need to be addressed to regain physiological patella tracking. Type 4 includes severe trochlea dysplasia with loss of patella tracking. Usually trochleaplasty is needed to stabilize the patella and to prevent redislocation. Type 5 is based on patella maltracking without instability and can be found in patients with a pathological knee baseline or special forms of torsional deformities. Although patella dislocations in trained athletes are seldom due to the stabilizing muscular status, the treatment strategy is similar to that of normal persons. Additional cartilage injuries, type of sports and time for rehabilitation have to be considered for optimal treatment. PMID:25182007

Frosch, K H; Akoto, R; Schmeling, A

2014-10-01

13

Cement penetration after patella venting  

Microsoft Academic Search

There is a high rate of patellofemoral complications following total knee arthroplasty. Optimization of the cement–bone interface by venting and suction of the tibial plateau has been shown to improve cement penetration. Our study was designed to investigate if venting the patella prior to cementing improved cement penetration.Ten paired cadaver patellae were allocated prior to resurfacing to be vented or

Christopher W. Jones; Li-On Lam; Adam Butler; David J. Wood; William R. Walsh

2009-01-01

14

Asymmetrical total knee arthroplasty does not improve patella tracking: a study without patella resurfacing  

Microsoft Academic Search

It is often suggested that patella tracking after total knee arthroplasty (TKA) with an asymmetrical patella groove is more\\u000a physiological than with a symmetrical patella groove. Therefore, this study tried to address two questions: what is the effect\\u000a of TKA on patella tracking, and is patella tracking after asymmetrical TKA more physiological than patella tracking after\\u000a symmetrical TKA? The patellar

Marco Barink; Huub Meijerink; Nico Verdonschot; Albert van Kampen; Maarten de Waal Malefijt

2007-01-01

15

Plating of patella fractures: techniques and outcomes.  

PubMed

Operative treatment of displaced patella fractures with tension band fixation remains the gold standard, but is associated with a significant rate of complications and symptomatic implants. Despite the evolution of tension band fixation to include cannulated screws, surprisingly little other development has been made to improve overall patient outcomes. In this article, we present the techniques and outcomes of patella plating for displaced patella fractures and patella nonunions. PMID:24343252

Taylor, Benjamin C; Mehta, Sanjay; Castaneda, Joaquin; French, Bruce G; Blanchard, Chris

2014-09-01

16

Cement penetration after patella venting.  

PubMed

There is a high rate of patellofemoral complications following total knee arthroplasty. Optimization of the cement-bone interface by venting and suction of the tibial plateau has been shown to improve cement penetration. Our study was designed to investigate if venting the patella prior to cementing improved cement penetration. Ten paired cadaver patellae were allocated prior to resurfacing to be vented or non-vented. Bone mineral density (BMD) was measured by DEXA scanning. In vented specimens, a 1.6 mm Kirschner wire was used to breach the anterior cortex at the center. Specimens were resurfaced with standard Profix instrumentation and Versabond bone cement (Smith and Nephew PLC, UK). Cement penetration was assessed from Faxitron and sectioned images by a digital image software package (ImageJ V1.38, NIH, USA). Wilcoxon rank sum test was used to assess the difference in cement penetration between groups. The relationship between BMD and cement penetration was analyzed by Pearson correlation coefficient. There was a strong negative correlation between peak BMD and cement penetration when analyzed independent of experimental grouping (r(2)=-0.812, p=0.004). Wilcoxon rank sum testing demonstrated no significant difference (rank sum statistic W=27, p=0.579) in cement penetration between vented (10.53%+/-4.66; mean+/-std dev) and non-vented patellae (11.51%+/-6.23; mean+/-std dev). Venting the patella using a Kirschner wire does not have a significant effect on the amount of cement penetration achieved in vitro using Profix instrumentation and Versabond cement. PMID:19010682

Jones, Christopher W; Lam, Li-On; Butler, Adam; Wood, David J; Walsh, William R

2009-01-01

17

Cercaria patellae Lebour, 1911 developing in Patella vulgata is the cercaria of Echinostephilla patellae (Lebour, 1911) n. comb. (Digenea, Philophthalmidae)  

Microsoft Academic Search

The echinostome cercaria,Cercaria patellae Lebour, 1911, which develops in the limpetPatella vulgata (Prosobranchia, Diotocardia, Patellidae), was investigated by light and scanning microscopy. The highest prevalence of limpets with rediae\\/cercariae occurred on bare rocks on the upper part of the shore. The prevalence was higher in larger snails and in those which had an orange foot-sole. The cercariae penetrated into other

Astrid H. Kollien

1996-01-01

18

Introduction Nail-patella syndrome (also called hereditary onycho-  

E-print Network

Introduction Nail-patella syndrome (also called hereditary onycho- osteodysplasia) is a relatively patellae. One-third to one-half of the patients, however, also suffer from hematuria and proteinuria- type remains unclear. In 1998 the first mutations that lead to the develop- ment of nail-patella

Witzgall, Ralph - Naturwissenschaftliche Fakultät III

19

Kidney disease in nail–patella syndrome  

Microsoft Academic Search

Nail–patella syndrome (NPS) is a pleiotropic autosomal-dominant disorder due to mutations in the gene LMX1B. It has traditionally\\u000a been characterized by a tetrad of dermatologic and musculoskeletal abnormalities. However, one of the most serious manifestations\\u000a of NPS is kidney disease, which may be present in up to 40% of affected individuals. Although LMX1B is a developmental LIM-homeodomain\\u000a transcription factor, it

Kevin V. Lemley

2009-01-01

20

Recreational runners with patellofemoral pain exhibit elevated patella water content.  

PubMed

Increased bone water content resulting from repetitive patellofemoral joint overloading has been suggested to be a possible mechanism underlying patellofemoral pain (PFP). To date, it remains unknown whether persons with PFP exhibit elevated bone water content. The purpose of this study was to determine whether recreational runners with PFP exhibit elevated patella water content when compared to pain-free controls. Ten female recreational runners with a diagnosis of PFP (22 to 39years of age) and 10 gender, age, weight, height, and activity matched controls underwent chemical-shift-encoded water-fat magnetic resonance imaging (MRI) to quantify patella water content (i.e., water-signal fraction). Differences in bone water content of the total patella, lateral aspect of the patella, and medial aspect of the patella were compared between groups using independent t tests. Compared with the control group, the PFP group demonstrated significantly greater total patella bone water content (15.4±3.5% vs. 10.3±2.1%; P=0.001), lateral patella water content (17.2±4.2% vs. 11.5±2.5%; P=0.002), and medial patella water content (13.2±2.7% vs. 8.4±2.3%; P<0.001). The higher patella water content observed in female runners with PFP is suggestive of venous engorgement and elevated extracellular fluid. In turn, this may lead to an increase in intraosseous pressure and pain. PMID:24906520

Ho, Kai-Yu; Hu, Houchun H; Colletti, Patrick M; Powers, Christopher M

2014-09-01

21

Tophaceous Gout of the Patella: A Report of Two Cases  

PubMed Central

Introduction. Tophaceous gout of the patella is rare and may masquerade as a tumour or tumour-like condition. Cases. We report two patients with gout involving the patella, one complicated by a pathological fracture and the other occurring in a bipartite patella in a young adult. Discussion. Typical imaging appearances and measurement of serum urate will usually confirm the diagnosis but, occasionally, the serum urate level may be normal in active gout and in such cases, a biopsy will be required. Conclusion. Gout of the patella may masquerade as a tumour or tumour-like condition and it is important to consider gout in the differential diagnosis. PMID:23198243

Hopper, Graeme; Gupta, Sanjay; Bethapudi, Sarath; Ritchie, David; MacDuff, Elaine; Mahendra, Ashish

2012-01-01

22

Sclerochronology and geochemical variation in limpet shells (Patella vulgata): A new archive to reconstruct coastal sea  

E-print Network

Sclerochronology and geochemical variation in limpet shells (Patella vulgata): A new archive of the European limpet, Patella vulgata, accumulated in archaeological deposits can potentially provide much

Schöne, Bernd R.

23

Infrapatellar contracture syndromeAn unrecognized cause of knee stiffness with patella entrapment and patella infera  

Microsoft Academic Search

Infrapatellar Contracture Syndrome (IPCS) is an infre quently recognized cause of posttraumatic knee mor bidity. Unique to this group of patients is the combina tion of restricted knee extension and flexion associated with patella entrapment. IPCS can occur primarily as an exaggerated pathologic fibrous hyperplasia of the anterior soft tissues of the knee beyond that associated with normal healing. It

Lonnie E. Paulos; Thomas D. Rosenberg; John Drawbert; James Manning; Paul Abbott

1987-01-01

24

Patella maltracking in posterior-stabilized total knee arthroplasty.  

PubMed

Maltracking of the patella component in total knee arthroplasty usually leads to complications such as subluxation, dislocation, fracture, excessive wear, or implant failure. After using a new posterior-stabilized total knee arthroplasty and a specific protocol for the patellofemoral articulation we determined the incidence of lateral retinacular release and patella complications. We retrospectively reviewed 255 consecutive primary posterior-stabilized total knee arthroplasties with an anatomic femoral component and a three-peg offset-dome patella. Component alignment was achieved using Whiteside's lines for the femoral component, the medial border of the tubercle for the tibial component, and previously reported techniques for the patella. Lateral release was performed in 15 knees (6.2%), most of which had excessive preoperative valgus (mean, 15 degrees). There were no reoperations for the patellofemoral joint at a mean followup of 3.7 years (range, 2-7 years). Two patients had asymptomatic osteonecrosis of the patella with complete radiolucent lines, and one patella fracture was treated with immobilization. We believe patella maltracking a largely avoidable problem in total knee arthroplasty. We found a low incidence of lateral retinacular release and patella complications using these components and this protocol for the patellofemoral articulation. PMID:16936588

Lachiewicz, Paul F; Soileau, Elizabeth S

2006-11-01

25

Should the patella be resurfaced during total knee replacement?  

Microsoft Academic Search

Patellar resurfacing during total knee replacement (TKR) has been a controversial subject for many years. In 1990 a randomised prospective study was started to compare policies of resurfacing, not resurfacing and selectively resurfacing the patella. One hundred and twenty-five cases (suitable for a cruciate sparing TKR) were randomised. At the 5-year review, the group in which the patella had not

John H Newman; Christopher E Ackroyd; Nilen A Shah; Theo Karachalios

2000-01-01

26

Biomechanics of the patella in total knee replacement  

Microsoft Academic Search

An anatomical shape for the trochlea of the femoral component is an advantage in total knee design because in many cases the natural patella is preserved. The trochlea profile can be described as having a V-shape, with a wide angle and a circular base. In such cases the plastic patella should have the same profile, resulting in a generally conical

Peter S. Walker

2001-01-01

27

Early outcomes of patella resurfacing in total knee arthroplasty  

PubMed Central

Background Patella resurfacing in total knee arthroplasty is a contentious issue. The literature suggests that resurfacing of the patella is based on surgeon preference, and little is known about the role and timing of resurfacing and how this affects outcomes. Methods We analyzed 134,799 total knee arthroplasties using data from the Australian Orthopaedic Association National Joint Replacement Registry. Hazards ratios (HRs) were used to compare rates of early revision between patella resurfacing at the primary procedure (the resurfacing group, R) and primary arthroplasty without resurfacing (no-resurfacing group, NR). We also analyzed the outcomes of NR that were revised for isolated patella addition. Results At 5 years, the R group showed a lower revision rate than the NR group: cumulative per cent revision (CPR) 3.1% and 4.0%, respectively (HR = 0.75, p < 0.001). Revisions for patellofemoral pain were more common in the NR group (17%) than in the R group (1%), and “patella only” revisions were more common in the NR group (29%) than in the R group (6%). Non-resurfaced knees revised for isolated patella addition had a higher revision rate than patella resurfacing at the primary procedure, with a 4-year CPR of 15% and 2.8%, respectively (HR = 4.1, p < 0.001). Interpretation Rates of early revision of primary total knees were higher when the patella was not resurfaced, and suggest that surgeons may be inclined to resurface later if there is patellofemoral pain. However, 15% of non-resurfaced knees revised for patella addition are re-revised by 4 years. Our results suggest an early beneficial outcome for patella resurfacing at primary arthroplasty based on revision rates up to 5 years. PMID:19968604

Clements, Warren J; Miller, Lisa; Whitehouse, Sarah L; Graves, Stephen E; Ryan, Philip

2010-01-01

28

Population dynamics of patella vulgata in orkney  

NASA Astrophysics Data System (ADS)

A population of Patella vulgata has been studied at Dyke-end, in Orkney. The population had a polymodal distribution, within which several year-classes were identified. Spawning occured between January and April each year and the first signs of spat settlement were recorded between August and October. Growth was suppressed over the winter months and increased during the summer, although the mature proportion of the population showed a reduction in growth rate at the onset of gonad development. Annual fluctuations in population density were attributed to spat recruitment and subsequent mortality of animals of < 30 mm lenght; little mortality of lager animals occurred.

Baxter, J. M.

29

Stress analysis in patella by three-dimensional photoelasticity  

NASA Astrophysics Data System (ADS)

In this paper, stress distribution in patella was studied by 3-D photoelastic experiments and finite element calculations. The experimental conditions were in good agreement with that of body mechanics: (1) The ratios of m. quadriceps femoris force FQ to lig. patella force FP were 1.03 - 1.42. (2) The angles between FQ and FP were 8.4 degree(s) - 18.7 degree(s). (3) The ratio of modulus of elasticity for epoxy resin and silicon rubber matched that for patella and cartilage, i.e., 145:1. The principal stresses and their path line, normal stresses, and contact stresses between patella and ossis femoris were determined in various flexion angles (15 degree(s), 30 degree(s), 45 degree(s), 60 degree(s), 75 degree(s), 90 degree(s)). Two of the correlations were: (1) Maximum principal stress in the front of patella; (sigma) max equals 35.8Wexp(0.024(alpha) ) KPa. (2) Maximum contact stress between patella and ossis femoris; (sigma) max equals -(6.86 - 0.14(alpha) + 0.02(alpha) 2)W KPa where W was body weight subjected by a single foot. It was proved that the transverse break of patella resulted from the case that the principle stress in the front of patella exceeded ultimate tensile strength. And Tension Band Wiring (TBW) therapy conformed to the law of physiological stress field. A modified K-needles position in TBW therapy was suggested. These results are useful for further research of human patella mechanics and recovery therapy. No similar result has been found in American MEDLIN Data Bank.

Chen, Riqi; Zhang, Jianxing; Jiang, Kunsheng

1991-12-01

30

Irreducible, incarcerated vertical dislocation of patella into a Hoffa fracture.  

PubMed

Rotational dislocations of patella, which involve rotation of the patella around a horizontal or vertical axis are rare. These rotational dislocations of patella are difficult to reduce by close methods. These dislocations can have associated osteochondral and retinacular injury. We report a case of a 20-year-old male who presented with swelling and pain in the right knee following a motor cycle accident. Radiological evaluation using the computed tomography revealed a patellar dislocation with a concomitant Hoffa fracture. Patella was rotated around the vertical axis and was incarcerated into the Hoffa fracture. This is a very rare injury and first of its kind to be reported. The difficulties in diagnosis, mechanism of injury and management have been discussed. We feel closed reduction of such an injury is likely to fail and open reduction is recommended. PMID:25298564

Soraganvi, Prasad C; Narayan Gowda, Bs; Rajagopalakrishnan, Ramakanth; Gavaskar, Ashok S

2014-09-01

31

How to address the patella in revision total knee arthroplasty.  

PubMed

Patellar issues need to be carefully addressed during any revision TKA and the surgeon often faces the question of what to do with the patella at the time of revision. The choice of treatment is often made by balancing what is technically feasible with the risk of potential complications and takes into account the reason for the revision, the type of implant (i.e., metal-backing or all-polyethylene), the duration of implantation, the fixation, the stability, the sterilization technique, the wear, the presence of osteolysis, the compatibility with the femoral component, and most importantly the remaining bone stock. The various treatment options then include retention of the patellar component, revision of the patellar component, removal of the component with retention of the patellar bony shell (patelloplasty or resection arthroplasty), excision of the patella (partial or total patellectomy), secondary resurfacing, and reconstruction/augmentation of the patellar bone stock. Isolated patellar revision is associated with a high complication rate and recurrent failure when poor patellar tracking, incongruent designs and malalignment of the femoral and tibial components exist. Retention of a well-fixed all-PE (non-oxidized) patella is advocated where possible and revision of metal-backed patella is recommended (unless well fixed with poor bone stock). In the situation of a deficient patella, patelloplasty, augmentation procedures and very rarely patellectomy are other viable options. PMID:18819807

Maheshwari, Aditya V; Tsailas, Panagiotis G; Ranawat, Amar S; Ranawat, Chitranjan S

2009-03-01

32

An anatomically based patient-specific finite element model of patella articulation: towards a diagnostic tool  

Microsoft Academic Search

A 3D anatomically based patient-specific finite element (FE) model of patello-femoral (PF) articulation is presented to analyse the main features of patella biomechanics, namely, patella tracking (kinematics), quadriceps extensor forces, surface contact and internal patella stresses. The generic geometries are a subset from the model database of the International Union of Physiological Sciences (IUPS) (

J. W. Fernandez; P. J. Hunter

2005-01-01

33

Association of Increased Knee Flexion and Patella Clunk Syndrome After Mini-Subvastus Total Knee Arthroplasty  

Microsoft Academic Search

This study reviewed 747 consecutive posterior stabilized total knee arthroplasty (TKA) to explain the increased incidence of patella clunk syndrome that occurred when the surgeon switched from a medial parapatellar arthrotomy to a mini-subvastus (MIS) TKA technique. The incidence of patella clunk syndrome increased with increased postoperative knee flexion. Six weeks after surgery, knees that developed patella clunk had a

William C. Schroer; Paul J. Diesfeld; Mary E. Reedy; Angela LeMarr

2009-01-01

34

Use of a patella marker to improve tracking of dynamic hip rotation range of motion  

E-print Network

Use of a patella marker to improve tracking of dynamic hip rotation range of motion Tishya A effectiveness of a patella marker in tracking hip rotation range of motion in comparison with traditional thigh wands. In controlled trials of isolated hip internal­ external rotation, the patella marker detected 98

Valero-Cuevas, Francisco

35

A neurological phenotype in nail patella syndrome (NPS) patients illuminated by studies of murine  

E-print Network

ARTICLE A neurological phenotype in nail patella syndrome (NPS) patients illuminated by studies, University of Texas MD Anderson Cancer Center, Houston TX, USA Nail patella syndrome (NPS) is an autosomal.ejhg.5201332 Published online 24 November 2004 Keywords: nail patella syndrome; LMX1B; neuronal migration

Kharasch, Evan

36

Strapline: Original Article1 Recent changes in the distribution of a marine gastropod, Patella rustica2  

E-print Network

1 Strapline: Original Article1 Recent changes in the distribution of a marine gastropod, Patella author: fplima@fc.up.pt14 15 Running Head16 Changes in the distribution of Patella. rustica17 18 ABSTRACT19 20 Aim Recent colonization of northern Portuguese shores by Patella rustica Linnaeus, 1758, led to

Power, Anne Marie

37

Patellar Maltracking Is Prevalent Among Patellofemoral Pain Subjects with Patella Alta: An Upright, Weightbearing MRI Study  

E-print Network

Patellar Maltracking Is Prevalent Among Patellofemoral Pain Subjects with Patella Alta: An Upright is to determine if patellar maltracking is more prevalent among patellofemoral (PF) pain sub- jects with patella alta compared to subjects with normal patella height. We imaged 37 PF pain and 15 pain free subjects

Delp, Scott

38

Patella lead x-ray fluorescence measurements are independent of sample orientation.  

PubMed

In vivo x-ray fluorescence bone lead measurements assess long-term lead exposure. Tibia, calcaneus, and patella are the most commonly sampled bones. Patella measurements also include lead signals from the distal femur, proximal tibia, and synovium. It is therefore important to know whether the orientation of the patella relative to the measurement system substantially affects the measured patella lead concentrations and their measurement uncertainties. This study examined whether these parameters exhibited a dependence on the orientation of the patella with respect to the measurement system, a dependence that could arise from varying nonpatella contributions. There was no effect of orientation on measured patella lead concentration, but there was a highly significant effect of orientation on the measurement uncertainty. These data do not conclusively show that there are no nonpatella contributions to a patella lead measurement; rather, that any such contributions are not a function of measurement orientation over the range of orientations considered. Further study is required if the contribution of nonpatella tissues to a patella lead XRF-measured concentration is to be fully addressed. This study also filled a gap in the literature by quantifying the within-patella (29%) and between-patella (71%) variability of measured patella lead concentrations from replicate measures of nine patellae. PMID:11548953

Todd, A C; Godbold, J H; Moshier, E L; Khan, F A

2001-08-01

39

Patellar maltracking is prevalent among patellofemoral pain subjects with patella alta: an upright, weightbearing MRI study  

PubMed Central

The purpose of this study is to determine if patellar maltracking is more prevalent among patellofemoral (PF) pain subjects with patella alta compared to subjects with normal patella height. We imaged 37 PF pain and 15 pain free subjects in an open-configuration magnetic resonance imaging scanner while they stood in a weightbearing posture. We measured patella height using the Caton-Deschamps, Blackburne-Peel, Insall-Salvati, Modified Insall-Salvati, and Patellotrochlear indices, and classified the subjects into patella alta and normal patella height groups. We measured patella tilt and bisect offset from oblique-axial plane images, and classified the subjects into maltracking and normal tracking groups. Patellar maltracking was more prevalent among PF pain subjects with patella alta compared to PF pain subjects with normal patella height (two-tailed Fisher’s exact test, p < 0.050). Using the Caton-Deschamps index, 67% (8/12) of PF pain subjects with patella alta were maltrackers, whereas only 16% (4/25) of PF pain subjects with normal patella height were maltrackers. Patellofemoral pain subjects classified as maltrackers displayed a greater patella height compared to the pain free and PF pain subjects classified as normal trackers (two-tailed unpaired t-tests with Bonferroni correction, p < 0.017). This study adds to our understanding of PF pain in two ways - 1) we demonstrate that patellar maltracking is more prevalent in PF pain subjects with patella alta compared to subjects with normal patella height; and 2) we show greater patella height in PF pain subjects compared to pain free subjects using four indices commonly used in clinics. PMID:23165335

Pal, Saikat; Besier, Thor F.; Beaupre, Gary S.; Fredericson, Michael; Delp, Scott L.; Gold, Garry E.

2012-01-01

40

How to address the patella in revision total knee arthroplasty  

Microsoft Academic Search

Patellar issues need to be carefully addressed during any revision TKA and the surgeon often faces the question of what to do with the patella at the time of revision. The choice of treatment is often made by balancing what is technically feasible with the risk of potential complications and takes into account the reason for the revision, the type

Aditya V. Maheshwari; Panagiotis G. Tsailas; Amar S. Ranawat; Chitranjan S. Ranawat

2009-01-01

41

Spontaneous patella fracture presenting as osteomyelitis in focal dermal hypoplasia  

Microsoft Academic Search

We report the first case of the assessment and treatment of a spontaneous patellar fracture in a patient with Goltz syndrome—a rare dermal hypoplasia. This case illustrates the non-straightforward presentation of a spontaneous patellar fracture in seemingly osteoporotic bone stock further complicated by the inability to rule out osteomyelitis. In this confusing presentation, a high index of suspicion for patella

Eric L. Altschuler; Richard S. Yoon; Richard Dentico; Frank A. Liporace

42

3-D printouts of the tracheobronchial tree generated from CT images as an aid to management in a case of tracheobronchial chondromalacia caused by relapsing polychondritis.  

PubMed

This report concerns a 67 year old male patient with known advanced relapsing polychondritis complicated by tracheobronchial chondromalacia who is increasingly symptomatic and therapeutic options such as tracheostomy and stenting procedures are being considered. The DICOM files from the patient's dynamic chest CT in its inspiratory and expiratory phases were used to generate stereolithography (STL) files and hence print out 3-D models of the patient's trachea and central airways. The 4 full-sized models allowed better understanding of the extent and location of any stenosis or malacic change and should aid any planned future stenting procedures. The future possibility of using the models as scaffolding to generate a new cartilaginous upper airway using regenerative medical techniques is also discussed. PMID:24421951

Tam, Matthew David; Laycock, Stephen David; Jayne, David; Babar, Judith; Noble, Brendon

2013-08-01

43

3-D printouts of the tracheobronchial tree generated from CT images as an aid to management in a case of tracheobronchial chondromalacia caused by relapsing polychondritis  

PubMed Central

This report concerns a 67 year old male patient with known advanced relapsing polychondritis complicated by tracheobronchial chondromalacia who is increasingly symptomatic and therapeutic options such as tracheostomy and stenting procedures are being considered. The DICOM files from the patient’s dynamic chest CT in its inspiratory and expiratory phases were used to generate stereolithography (STL) files and hence print out 3-D models of the patient’s trachea and central airways. The 4 full-sized models allowed better understanding of the extent and location of any stenosis or malacic change and should aid any planned future stenting procedures. The future possibility of using the models as scaffolding to generate a new cartilaginous upper airway using regenerative medical techniques is also discussed. PMID:24421951

Tam, Matthew David; Laycock, Stephen David; Jayne, David; Babar, Judith; Noble, Brendon

2013-01-01

44

Ten-year Results of an Inset Biconvex Patella Prosthesis in Primary Knee Arthroplasty  

Microsoft Academic Search

The inset biconvex patella component is an alternative form of patella resurfacing in knee arthroplasty. We retrospectively\\u000a reviewed 433 patients in whom 521 patella prostheses were implanted before April 1997 to determine survivorship, factors associated\\u000a with failure of the implant, incidence of anterior knee pain, and factors that may be associated with the latter. We had clinical\\u000a results for 204

Sani Erak; Vaishnav Rajgopal; Steven J. MacDonald; Richard W. McCalden; Robert B. Bourne

2009-01-01

45

How are podocytes affected in nail–patella syndrome?  

Microsoft Academic Search

Nail–patella syndrome is an autosomal-dominant hereditary disease named for dysplastic fingernails and toenails and hypoplastic\\u000a or absent kneecaps evident in patients with the syndrome. Prognosis is determined by the nephropathy that develops in many\\u000a such patients. Besides podocyte foot-process effacement, pathognomonic changes in the kidney comprise electron-lucent areas\\u000a and fibrillar inclusions in the glomerular basement membrane. These characteristic symptoms are

Ralph Witzgall

2008-01-01

46

Should the patella be replaced in total knee replacement?  

Microsoft Academic Search

In 170 total knee arthroplasties for osteoarthritis 71 did not receive a patellar replacement (group A), while 99 knees had a cemented polyethylene patella (group B). The mean follow-up time was 36 months (30-50 months). In group A 10 patients underwent second-stage patellar resurfacing and in group B 2 knees underwent revision of the patellar component. Radiologically the average patellar

N. Badhe; G. Dewnany; P. J. Livesley

2001-01-01

47

Dorsal defect of the patella with fracture in a teenager  

Microsoft Academic Search

We report the case of a young boy who presented a dorsal defect of the patella (DDP) with fracture after a small sport trauma.\\u000a The patient’s parents (professional of health care) had been warned on a possible tumoral disease in a previous consultation\\u000a and claimed for an accurate diagnosis. Although fracture is rarely reported in DDP, the radiographic image strongly

Carlos Villas; Juan Pons-Villanueva

2010-01-01

48

[Diseases of the patella caused by clothing (author's transl)].  

PubMed

Fashionable clothing involving tight-fitting trousers and high heels forces human to adopt an attitude leading to diseases at the point of insertion of the tendons and of the cartilage of the patella. It is emphasized that malformations of the femoropatellar joint may possibly be caused by exogenous influences and may, therefore, be successfully treated by externally applied methods during the growth period. PMID:7222941

Rütten, M

1980-12-01

49

Management of extreme patella baja using in-situ hamstring tendon autograft.  

PubMed

Successful total knee arthroplasty requires a functioning extensor mechanism. Patella baja following total knee arthroplasty can cause extensor mechanism dysfunction and produce poor outcomes. We present a case of severe patella tendon shortening following revision total knee arthroplasty with almost complete ankylosis of the distal pole of the patella to the proximal tibia. This resulted in effective extensor mechanism dysfunction with pain and severely limited knee flexion. We report a novel method of reconstruction of the patella tendon at the time of revision arthroplasty together with the one-year clinical outcome and review of the literature. PMID:25002139

Moulton, L S; Davies, A P

2014-10-01

50

Q-angle undervalued? The relationship between Q-angle and medio-lateral position of the patella  

Microsoft Academic Search

Background. For an accurate quadriceps angle measurement, the patella must be centralised in the femoral trochlear groove, numerous authors have described lateral displacement of the patella in patellofemoral pain patients, this leads to the intriguing possibility that the Q-angle might be undervalued within patellofemoral pain patients who have laterally displaced patella.Method. 109 asymptomatic subjects (51 male, 58 female) were assessed.

Lee Herrington; Chris Nester

2004-01-01

51

Patella resurfacing: no benefit for the long-term outcome of total knee arthroplasty  

Microsoft Academic Search

. A follow-up of more than 10 years among patients who have undergone a total knee arthroplasty (TKA) was performed to determine the significance of patella resurfacing for the long-term outcome. The clinical outcome was assessed by the Knee Society Score (KSS), and the radiological outcome was determined based on the Knee Society Roentgenographic Evaluation System. The patella was preserved

Michael Ogon; Frank Hartig; Christian Bach; Michael Nogler; Iris Steingruber; Rainer Biedermann

2002-01-01

52

Cartilage of the patella. Topographical variation of glycosaminoglycan content in normal and fibrillated tissue  

Microsoft Academic Search

The variation in the glycosaminoglycan content was studied at different sites of the patella, both where the cartilage was intact and where it showed varying degrees of fibrillation. It was found that when the cartilage surface was intact the glycosaminoglycan content was the same at the different sites of the patella. Local fibrillation always gave rise to a local lowering

C Ficat; A Maroudas

1975-01-01

53

The clinical history of mobile-bearing patella components in total knee arthroplasty.  

PubMed

Two hundred fifty-six primary cementless meniscal-bearing total knee arthroplasties were performed between May 1985 and January 1989. All knees were replaced with a low contact stress metal-backed anatomic mobile patella. The average patient follow-up was 11.5 years. No patellae were revised for failure of fixation and no dislocations or subluxations were reported. One patella was revised for polyethylene wear, and one well-functioning component was removed at the time of revision to facilitate range of motion and wound closure. The survival estimate at 12 years was 99.5%. Compared to the high incidence of failure of metal-backed fixed-bearing patellae components, the anatomic rotating patella provides durable long-term results with a low incidence of complications. PMID:11866161

Jordan, Louis R; Dowd, James E; Olivo, Jane L; Voorhorst, Paul E

2002-02-01

54

Spontaneous patella fracture presenting as osteomyelitis in focal dermal hypoplasia.  

PubMed

We report the first case of the assessment and treatment of a spontaneous patellar fracture in a patient with Goltz syndrome-a rare dermal hypoplasia. This case illustrates the non-straightforward presentation of a spontaneous patellar fracture in seemingly osteoporotic bone stock further complicated by the inability to rule out osteomyelitis. In this confusing presentation, a high index of suspicion for patella fracture should be maintained for patients with knee pain and osteoporosis on x-ray with a dysplastic syndrome. PMID:22000280

Altschuler, Eric L; Yoon, Richard S; Dentico, Richard; Liporace, Frank A

2012-08-01

55

Runners knee (image)  

MedlinePLUS

... forces on the knee, such as a misaligned patella. Chondromalacia is treated with rest or immobilization and ... is a problem with the alignment of the patella that cannot be corrected with therapy.

56

Linkage analysis of the Nail-patella syndrome  

SciTech Connect

Nail-patella syndrome (NPS) is an autosomal dominant disorder characterized by dysplasia of nails and patella, decreased mobility of the elbow, iliac horns, and, in some cases, nephropathy. The disorder has been mapped to the long arm of chromosome 9, but the precise localization and identity of the NPS gene are unknown. Linkage analysis in three NPS families, using highly informative dinucleotide repeat polymorphisms on 9q33-q34, confirmed linkage of NPS to this chromosome. Recombinations were detected, by two-point linkage analysis, between NPS and the centromeric markers D9S60 and the gelsolin gene and the telomeric markers D9S64 and D9S66, in one of the families. Haplotype analysis suggested an additional recombination between NPS and the argininosuccinate synthetase (ASS) gene. These results localize the NPS gene to an interval on 9q34.1, distal to D9S60 an proximal to ASS, comprising a genetic distance of {approximately}9 cM. This represents a significant refinement in the localization of the NPS gene. 25 refs., 2 figs., 1 tab.

Campeau, E.; Watkins, D.; Rouleau, G.A. [Montreal General Hospital, Quebec (Canada); Babul, R.; Der Kaloustian, V.M. [McGill Univ., Montreal (Canada); Buchanan, J.A.; Meschino, W. [North York General Hospital (Canada)

1995-01-01

57

Skull, patella and thigh cryptococcosis after a crashing injury of the temporal bone.  

PubMed

An unusual case of triple location (skull, patella and thigh) Cryptococcus neoformans is described. The peculiarity of the case is based on the probability of direct post-traumatic bone inoculation, subsequent seeding from skull to patella, thigh and cerebral spinal fluid (CSF), patella involvement, lack of evidence of lung involvement and lack of predisposing underlying disease. The response to surgery and a combination of amphotericin B and 5-flucytosine administration was favorable without relapse at follow-up after 7-year discontinuation of therapy. PMID:1875233

Dounis, E; Giamarellou, H; Peppas, T; Sfikakis, P

1991-04-01

58

Angiotensin converting enzyme in human synovium: increased stromal [125I]351A binding in rheumatoid arthritis  

Microsoft Academic Search

OBJECTIVETo determine whether tissue angiotensin converting enzyme (ACE) is increased in synovia from patients with rheumatoid arthritis, osteoarthritis or chondromalacia patellae.METHODSSections of synovia from patients with rheumatoid arthritis (n = 7), osteoarthritis (n = 7) or chondromalacia patellae (n = 6) were tested for immunoreactivity for ACE, and for binding of the ACE inhibitor [125I]351A. The amount of ACE was

David Andrew Walsh; John Catravas; John Wharton

2000-01-01

59

Human identification through the patella--Report of two cases.  

PubMed

The human identification process is often performed by the comparison between acquired post-mortem (PM) fingerprints, dental patterns, or DNA sample with ante-mortem (AM) databases. However, in some special situations alternative sources of human identifiers reveal valuable part as forensic tools. In this context, medical records of surgical interventions and morphological bone traits are useful in the anthropological environment, specifically for the PM examination of skeletal remains. The present study reports two cases of positive human identifications by the comparative analysis between AM and PM radiographic medical records of surgically treated human patella. The present outcome highlights the importance of storing and updating medical records in order to aid human identification processes in special forensic situations. PMID:24656324

Silva, Rhonan Ferreira; Franco, Ademir; Mendes, Solon Diego Santos Carvalho; Picoli, Fernando Fortes; de Azevedo Marinho, Décio Ernesto

2014-05-01

60

Early PROMs following total knee arthroplasty--functional outcome dependent on patella resurfacing.  

PubMed

Patella resurfacing during primary total knee arthroplasty (TKA) remains controversial. Variation in published results for patella resurfacing may potentially be explained by differences in design between TKA brands. We interrogated NJR-PROMs data to ascertain whether there is an early functional benefit to resurfacing the patella, both overall and for each of the five most popular primary knee designs through use of the Oxford Knee Score. A total of 8103 resurfaced TKAs and 15,290 nonresurfaced TKAs were studied. There was a large variation in the proportion of knees undergoing patella resurfacing by brand (Nexgen=16% versus Triathlon=52%). Patellar resurfacing did not significantly influence the magnitude of improvement in overall knee function or anterior knee-specific function irrespective of TKA brand or for cruciate retaining versus sacrificing designs. PMID:23769662

Baker, Paul N; Petheram, Timothy; Dowen, Daniel; Jameson, Simon S; Avery, Peter J; Reed, Mike R; Deehan, David J

2014-02-01

61

Medial quadriceps tendon-femoral ligament: surgical anatomy and reconstruction technique to prevent patella instability.  

PubMed

Detailed anatomic dissections of the deep medial knee retinaculum have shown a consistent prominent anatomic structure extending from the distal deep quadriceps tendon to the adductor tubercle region, forming a distinct medial quadriceps tendon-femoral ligament (MQTFL). Reconstruction of this anatomic structure has yielded consistent medial stabilization of the patellofemoral joint without drilling into the patella over more than 3 years in patients with recurrent patella instability and dislocation. Results are similar to those of MPFL reconstruction but with reduced risk of patella fracture, a known and serious complication of MPFL reconstruction. The reconstruction graft is secured at the anatomic femoral origin of the MQTFL and brought under the vastus medialis such that it may be woven and attached to the deep distal medial quadriceps tendon to provide a secure, reliable reproduction of the MQTFL and excellent stabilization of the patellofemoral joint without risk of patella fracture. PMID:23875137

Fulkerson, John P; Edgar, Cory

2013-05-01

62

Medial Quadriceps Tendon-Femoral Ligament: Surgical Anatomy and Reconstruction Technique to Prevent Patella Instability  

PubMed Central

Detailed anatomic dissections of the deep medial knee retinaculum have shown a consistent prominent anatomic structure extending from the distal deep quadriceps tendon to the adductor tubercle region, forming a distinct medial quadriceps tendon–femoral ligament (MQTFL). Reconstruction of this anatomic structure has yielded consistent medial stabilization of the patellofemoral joint without drilling into the patella over more than 3 years in patients with recurrent patella instability and dislocation. Results are similar to those of MPFL reconstruction but with reduced risk of patella fracture, a known and serious complication of MPFL reconstruction. The reconstruction graft is secured at the anatomic femoral origin of the MQTFL and brought under the vastus medialis such that it may be woven and attached to the deep distal medial quadriceps tendon to provide a secure, reliable reproduction of the MQTFL and excellent stabilization of the patellofemoral joint without risk of patella fracture. PMID:23875137

Fulkerson, John P.; Edgar, Cory

2013-01-01

63

Steroid-responsive nephrotic syndrome in a patient with nail-patella syndrome  

Microsoft Academic Search

Nail-patella syndrome (NPS) is a rare disorder with autosomal dominant mode of inheritance. We report a child with NPS and steroid-responsive, frequently relapsing nephrotic syndrome. The child had dystrophic nails, flexion contractures of both elbows and normal renal functions. X-rays of the knees and pelvis showed hypoplastic patellae and iliac horns. Renal histology was unremarkable with mild focal increase in

Pankaj Hari; Mukta Mantan; Amit Dinda; Smriti Hari; Arvind Bagga

2006-01-01

64

Biomimetic design of musculoskeletal humanoid knee joint with patella and screw-home mechanism  

Microsoft Academic Search

We are trying to create a novel musculoskeletal humanoid robot which has a humanlike structure. In this paper, we present a new knee joint which is usually simplified in robotics for high controllability. The knee joint has three human mimetic points, patella, screw-home mechanism and four-linked linkage. Patella is for a longer moment arm. Screw-home mechanism is for locking knee

Yuki Asano; Hironori Mizoguchi; Masahiko Osada; Toyotaka Kozuki; Junichi Urata; Tamon Izawa; Yuto Nakanishi; Kei Okada; Masayuki Inaba

2011-01-01

65

Reducing the Lateral Force Acting on the Patella Does Not Consistently Decrease Patellofemoral Pressures  

Microsoft Academic Search

Background: Extensor mechanism procedures that decrease the lateral component of the patellar tendon or quadriceps force acting on the patella do not consistently reduce pain.Hypothesis: Patellofemoral treatments do not consistently decrease patellofemoral pressures because of variations in the moments acting on the patella.Study Design: Computer simulation study.Methods: Computational models of 4 knees were constructed to characterize the patellofemoral pressure distribution

John J. Elias; Jennifer A. Cech; David M. Weinstein; Andrew J. Cosgrea

2004-01-01

66

The influence of kinematic conditions and design on the wear of patella-femoral replacements.  

PubMed

The success rate of patella-femoral arthroplasty varies between 44% and 90% in 17 years of follow-up. Several studies have been performed previously for assessing the surface wear in the patella-femoral joint. However, they have not included all six degrees of freedom. The aim of this study was to develop a six-axis patella-femoral joint simulator to assess the wear rate for two patellae designs (round and oval dome) at different kinematic conditions. An increase in patellar rotation from 1° to 4° led to a significantly (p<0.049) increased wear rate of round dome from 8.6 mm(3)/million cycles to 12.3 mm(3)/million cycles. The wear rate for oval dome increased from 6.3 mm(3)/million cycles to 14.5 mm(3)/million cycles. However, the increase was nonsignificant (p>0.08). The increase in wear rate was likely due to the higher cross shear. A decrease in patellar medial lateral displacement from passive to constrained resulted in a nonsignificant reduction in wear (p>0.06). There was no significant difference in wear rate between the two patellae designs (p>0.28). The volumetric wear under all conditions was positively correlated with the level of passive patellar tilt (rho>0.8). This is the first report of preclinical wear simulation of patella-femoral joint in a six-axis simulator under different kinematic conditions. PMID:24477888

Maiti, Raman; Fisher, John; Rowley, Liam; Jennings, Louise M

2014-02-01

67

Arthropathy and proteinuria: nail-patella syndrome revisited  

PubMed Central

Nail-patella syndrome (NPS) is a pleiotropic autosomal-dominant disorder due to mutations in the gene LMX1B. It has traditionally been characterized by a tetrad of dermatologic and musculoskeletal abnormalities. However, one of the most serious manifestations of NPS is kidney disease, which may be present in up to 40% of affected individuals. Although diagnosis can be made at birth, it is often missed, presumably due to the rarity of the condition. A 35-year-old female presented to our clinic with history of small joint pain of 6 months duration. In addition she complained of pedal edema off and on for the last 12 years. Prior to her current presentation she had been managed by a local doctor symptomatically. On evaluation, a nephrotic syndrome was obvious, but no secondary cause could be found. However, her physical examination was characteristic of NPS and keeping in view the autosomal dominant nature of the disorder all her three siblings were screened who too showed classical features of NPS. This rare syndrome as a cause of nephrotic range proteinuria is discussed in this report. The report underlines the importance of a good physical examination in a given clinical setting. PMID:25408626

Albishri, Jamal

2014-01-01

68

Surgical treatment of a chronically fixed lateral patella dislocation in an adolescent patient.  

PubMed

Acute patellar dislocation or subluxation is a common cause for knee injuries in the United States and accounts for 2% to 3% of all injuries. Up to 49% of patients will have recurrent subluxations or dislocations. Importance of both soft tissue (predominantly, the medial patellofemoral ligament, MPFL, which is responsible for 60% of the resistance to lateral dislocation) and bony constraint of femoral trochlea in preventing subluxation and dislocation is well documented. Acute patella dislocation will require closed reduction and management typically consist of conservative or surgical treatment depending on the symptoms and recurrence of instability. Most patients are diagnosed and treated in a timely manner. We present a 15 years old male with a missed traumatic lateral patella dislocation during childhood. The patient presented as an adolescent with a chronically fixed lateral patella dislocation and was management with surgery. The key steps in the surgical reconstruction of this patient required first mobilizing the patella with a lateral retinacular release and V-Y lengthening of the shortened or contracted quadriceps tendon. Then a combination of MPFL reconstruction using the semitendinosis autograft, tibial tubercle osteotomy with anterio-medialization, and lateral facetectomy was performed. At the one-year follow-up, our patient had improved knee range of motion and decrease in pain. Chronically fixed lateral dislocated patella is a rare and complex problem to manage in older patients that will require a thorough work-up and appropriate surgical planning along with reconstruction. PMID:23888199

Li, Xinning; Nielsen, Natalie M; Zhou, Hanbing; Stein, Beth Shubin; Shelton, Yvonne A; Busconi, Brian D

2013-06-01

69

Patella resurfacing in total knee arthroplasty using metal-backed rotating bearing components: a 2- to 10-year follow-up evaluation  

Microsoft Academic Search

Management of the patella in total knee arthroplasty (TKA) has become an important issue. Patella-related complications remain a major concern and have frequently been the reason for secondary intervention, whether resurfaced or not. Common modes of failures are increased polyethylene (PE) wear, PE fractures, component dissociation (loosening or PE spinout), and patella fractures. This study evaluated 235 cases of low

Urs K. Munzinger; Jeannette Petrich; Jens G. Boldt

2001-01-01

70

A comparison between the patella and the calcaneus using ultrasound velocity and attenuation as predictors of bone mineral density  

NASA Astrophysics Data System (ADS)

The bone mineral density (BMD), ultrasound velocity (UV) and attenuation were examined in sixteen matched sets of human patellae and calcanei. For the sixteen calcanei, BMD was strongly correlated with all ultrasound parameters. Calcaneal UV appeared to be inferior to attenuation in the ability to predict BMD. For the sixteen patellae, the average UV was found to be greater in the superior/inferior direction than in the anterior/posterior and medial/lateral directions. It was found that patella BMD was significantly correlated with each of three directional ultrasound velocities. The relationship between BMD and ultrasound attenuation parameters was not significant in the patella. A comparative study of the two different bone sets demonstrated that the BMDs of the patella and calcaneus were significantly correlated with each other. Ultrasound velocity of calcaneus, measured in the medial/lateral direction, was not significantly associated with any of three directional ultrasound velocities in the patella. Similarly, ultrasound attenuation parameters of calcaneus were not significantly correlated with those of patella. The present study also demonstrated evidence that when predicting BMDs at their respective sites using ultrasound, the calcaneus appeared to be superior to the patella.

Han, S. M.; Davis, J.

1997-10-01

71

Patella retention versus replacement in total knee arthroplasty; functional and clinimetric aspects  

Microsoft Academic Search

Introduction  Whether to resurface the patella or not in total knee arthroplasty still remains undecided. Classical scores and questionnaires\\u000a might not be responsive or demanding enough. This study used two accelerometer based systems to study the hypothesis whether\\u000a performance based tests are able to detect a difference in patients with or without a resurfaced patella.\\u000a \\u000a \\u000a \\u000a Method  In this retrospective study 53 patients

Wouter L. W. van Hemert; Rachel Senden; Bernd Grimm; Arnold D. M. Kester; Matthijs J. A. van der Linde; Ide C. Heyligers

2009-01-01

72

Vertical Open Patella Fracture, Treatment, Rehabilitation and the Moment to Fixation  

PubMed Central

Patella fracture is relatively uncommon and the vertical trace fracture represents almost 12-17%. The open patella fracture expresses 6-30%. The association of these two uncommon conditions was the aim of this case report even as the treatment and the moment of fixation (definitive surgical treatment). A 27-year-old man after a motorcycle accident showed an open patella fracture classified as a Gustilo and Anderson type IIIA lesion. The patient was immediately treated with precocious surgery fixation with a modified tension band which consists of two parallel K-wires positioned orthogonal to the fracture line and a cerclage wire shaped anteriorly at patella as an eight. The premature fixation benefited the infection prevention and provided earlier joint motion, which increased the nutrition of articular cartilage. Six months postoperatively, the patient had a satisfactory joint motion with full extension and 116° of joint flexion and returned to his daily life activities without restriction. Twelve months postoperatively, the patient had full extension and 120° of knee flexion without pain, joint effusion and instability. Muscle strength force was considered normal at grade V. In conclusion, early chirurgic treatment and precocious articular mobilization improve prognosis, suggesting that the employment of these practices should be adopted whenever possible in most of the open fractures.

Larangeira, Joao Alberto; Bellenzier, Liliane; Rigo, Vanessa da Silva; Ramos Neto, Elias Josue; Krum, Francisco Fritsch Machry; Ribeiro, Tiango Aguiar

2015-01-01

73

THE ECOLOGY OF PATELLA LINNAEUS FROM THE CAPE PENINSULA, SOUTH AFRICA. 2. REPRODUCTIVE CYCLES  

Microsoft Academic Search

The gonad structure and cycles of seven Patella spp. are described. Most spawn once a year. P. cochlear, P. argenvillei, P. barbara, P. granatina and P. granularis are autumn to winter breeders spawning in May-June. P. oculus spawns in September and P. longicosta in October-November. Partial spawning was recorded for P. cochlear, prior to the attainment of maximum maturity. In

G. M. BRANCH

1974-01-01

74

Influence of patellofemoral articular geometry and material on mechanics of the unresurfaced patella.  

PubMed

Patellar resurfacing during knee replacement is still under debate, with several studies reporting higher incidence of anterior knee pain in unresurfaced patellae. Congruency between patella and femur impacts the mechanics of the patellar cartilage and strain in the underlying bone, with higher stresses and strains potentially contributing to cartilage wear and anterior knee pain. The material properties of the articulating surfaces will also affect load transfer between femur and patella. The purpose of this study was to evaluate the mechanics of the unresurfaced patella and compare with natural and resurfaced conditions in a series of finite element models of the patellofemoral joint. In the unresurfaced analyses, three commercially available implants were compared, in addition to an 'ideal' femoral component which replicated the geometry, but not the material properties, of the natural femur. Hence, the contribution of femoral component material properties could be assessed independently from geometry changes. The ideal component tracked the kinematics and patellar bone strain of the natural knee, but had consistently inferior contact mechanics. In later flexion, compressive patellar bone strain in unresurfaced conditions was substantially higher than in resurfaced conditions. Understanding how femoral component geometry and material properties in unresurfaced knee replacement alters cartilage contact mechanics and bone strain may aid in explaining why the incidence of anterior knee pain is higher in the unresurfaced population, and ultimately contribute to identifying criteria to pre-operatively predict which patients are suited to an unresurfaced procedure and reducing the incidence of anterior knee pain in the unresurfaced patient population. PMID:22727469

Fitzpatrick, Clare K; Rullkoetter, Paul J

2012-07-26

75

The Effect of Bracing on Patella Alignment and Patellofemoral Joint Contact Area  

Microsoft Academic Search

POWERS, C. M., S. R. WARD, L.-D. CHAN, Y.-J. CHEN, and M. R. TERK. The Effect of Bracing on Patella Alignment and Patellofemoral Joint Contact Area. Med. Sci. Sports Exerc., Vol. 36, No. 7, pp. 1226 -1232, 2004. Purpose: To examine the influence of two patellofemoral braces on pain response, patellar alignment, and patellofemoral joint contact area in persons with

CHRISTOPHER M. POWERS; SAMUEL R. WARD; LI-DER CHAN; YU-JEN CHEN; MICHAEL R. TERK

2004-01-01

76

Medial subluxation of the patella as a complication of lateral retinacular release  

Microsoft Academic Search

We examined 54 patients (60 knees) referred to us because of their failure to improve, or because of a worsening of their preoperative symptoms, following an arthroscopic lateral retinacular release. Thirty knees developed medial subluxation of the patella postoper atively. This disabling condition is new to us. It is previously unreported as a complication of arthroscopic lateral retinacular release. Anterior

Jack C. Hughston; Melvin Deese

1988-01-01

77

INTEGRATING EDGE DETECTION AND THRESHOLDING APPROACHES TO SEGMENTING FEMORA AND PATELLAE FROM MAGNETIC RESONANCE IMAGES  

Microsoft Academic Search

Anterior knee pain (AKP) is a common pathological condition. The most obvious problem causing knee pain is the abnormal patellar tracking mechanism. For computerized knee joint analysis, how to successfully segment the knee bones is an import issue. This paper presents a simple while effective algorithm for fully automatic femur and patella segmentation for magnetic resonance (MR) knee images through

JIANN-SHU LEE; YI-NUNG CHUNG

2005-01-01

78

Metallothionein concentrations in a population of Patella aspera: variation with size  

Microsoft Academic Search

The determination of metallothionein (MT) concentrations in species with different feeding habits is important from the ecotoxicological point of view because it provides a better understanding of the role of these proteins in metal uptake pathways. The main objective was study the variation of MT and metal (Cd, Cu and Zn) concentrations with size and weight in the limpets Patella

M. J Bebianno; A Cravo; C Miguel; S Morais

2003-01-01

79

Partitioning of trace metals between soft tissues and shells of Patella aspera  

Microsoft Academic Search

This paper describes the partitioning of iron, manganese, zinc, copper, cadmium, cobalt, nickel and lead between the soft tissues and the shells of the gastropod mollusc Patella aspera. Specimens of the limpet P. aspera were collected from a clean coastal marine site (CMS) and from an estuarine contaminated site (ECS) on the south coast of Portugal. Fe and Zn concentrations

A. Cravo; M. J. Bebianno; P. Foster

2004-01-01

80

Dye-coupling between blastomeres in early embryos of Patella vulgata (mollusca, gastropoda): Its relevance for cell determination  

Microsoft Academic Search

During the early development of the molluscPatella, the dorsoventral axis is established after the fifth cleavage due to direct interaction between the animal micromeres and one of the vegetal macromeres. This vegetal macromere is thereby induced to become the mesentoblast mother cell (3D). In this study we have examined intercellular communication in earlyPatella embryos by monitoring the transfer of the

Adriaan W. C. Dorresteijn; Huibert A. Wagemaker; Siegfried W. Laat; Jo A. M. Biggelaar

1983-01-01

81

* Corresponding author. Tel.: 916 752 6220; fax: 916 752 4158; e-mail: mlhull@ucdavis.edu  

E-print Network

causes, degeneration of the patella cartilage as a result of repeated overloading is a probable cause on the underside of the patella, the condition is called chondromalacia (Insall, 1982; Mow and Sos- lowsky, 1991; Goodfellow et al., 1976). In those cases where overloading of the patella occurs, the increased loads can

Hull, Maury

82

Metaphylogenomic and Potential Functionality of the Limpet Patella pellucida's Gastrointestinal Tract Microbiome  

PubMed Central

This study investigated the microbial diversity associated with the digestive tract of the seaweed grazing marine limpet Patella pellucida. Using a modified indirect DNA extraction protocol and performing metagenomic profiling based on specific prokaryotic marker genes, the abundance of bacterial groups was identified from the analyzed metagenome. The members of three significantly abundant phyla of Proteobacteria, Firmicutes and Bacteroidetes were characterized through the literature and their predicted functions towards the host, as well as potential applications in the industrial environment assessed. PMID:25334059

Dudek, Magda; Adams, Jessica; Swain, Martin; Hegarty, Matthew; Huws, Sharon; Gallagher, Joe

2014-01-01

83

The ''hot patella'' sign: is it of any clinical significance. Concise communication  

SciTech Connect

The presence of the ''hot patella'' sign was evaluated in a prospective study of 200 consecutive bone scans, and in a review of scans from 148 patients with various metabolic bone disorders and 61 patients with lung carcinoma. The incidence was found to be 31%, 26% and 31% respectively. This sign is an extremely common scan finding and may be seen in association with a wide variety of disorders. It is concluded that this sign cannot be considered to be of diagnostic value.

Fogelman, I.; McKillop, J.H.; Gray, H.W.

1983-04-01

84

Tunnel widening in anterior cruciate ligament reconstruction: a prospective evaluation of hamstring and patella tendon grafts  

Microsoft Academic Search

We report a prospective series evaluating the incidence and degree of tunnel widening in a well-matched series of patients\\u000a receiving a hamstring or patella tendon graft for anterior cruciate ligament (ACL) deficiency. We correlated tunnel widening\\u000a with clinical factors, knee scores, KT-1000 and isokinetic muscle strength to determine the clinical significance of this\\u000a finding. Seventy-three patients at least 12 months

M. G. Clatworthy; P. Annear; J.-U. Bulow; R. J. Bartlett

1999-01-01

85

Metaphylogenomic and Potential Functionality of the Limpet Patella pellucida's Gastrointestinal Tract Microbiome.  

PubMed

This study investigated the microbial diversity associated with the digestive tract of the seaweed grazing marine limpet Patella pellucida. Using a modified indirect DNA extraction protocol and performing metagenomic profiling based on specific prokaryotic marker genes, the abundance of bacterial groups was identified from the analyzed metagenome. The members of three significantly abundant phyla of Proteobacteria, Firmicutes and Bacteroidetes were characterized through the literature and their predicted functions towards the host, as well as potential applications in the industrial environment assessed. PMID:25334059

Dudek, Magda; Adams, Jessica; Swain, Martin; Hegarty, Matthew; Huws, Sharon; Gallagher, Joe

2014-01-01

86

Minor and trace elements in the shell of Patella aspera (Röding 1798)  

Microsoft Academic Search

Specimens of the limpet Patella aspera were collected from a clean, coastal marine site and a contaminated estuary on the south coast of Portugal. The shells were analysed individually for their minor (Mg, Sr) and trace element (Fe, Mn, Zn) content. Mean concentrations of these elements in the shell of P. aspera were 4651, 1318, 35.8, 29.9 and 5.5 ?g

A Cravo; P Foster; M. J Bebianno

2002-01-01

87

The patella and tibial condyle position after combined and after closing wedge high tibial osteotomy  

Microsoft Academic Search

High tibial osteotomy changes the patella and tibial condyle position, which makes the subsequent total knee replacement technically\\u000a demanding. From 1 January 1993 to 31 December 2000, combined osteotomy [After the first osteotomy made 2 cm distally to the\\u000a joint line, a bone wedge is removed based laterally. Its tip ends at the center of the tibial condyle (half bone wedge).

Miklós Papp; Zoltán Csernátony; Sándor Kazai; Zoltán Károlyi; László Róde

2007-01-01

88

Correlation between the Q angle and the patella position: a clinical and axial computed tomography evaluation  

Microsoft Academic Search

The purpose of this study was to evaluate the significance of the Q angle with respect to the patella position. Fifty-six\\u000a knee joints of 34 patients (15 bilateral) with chronic patellofemoral pain were prospectively evaluated. All patients were\\u000a examined by the same orthopaedic surgeon (R.M.B.) and the Q angle measured clinically and using long radiographs. Additionally,\\u000a axial computed tomography (CT)

R. M. Biedert; K. Warnke

2001-01-01

89

Patella re-alignment in children with a modified Grammont technique  

PubMed Central

Background and purpose In skeletally immature patients, surgical options due to recurrent patella dislocation are limited, because bony procedures bear the risk of growth disturbances. In this retrospective study, we report the long-term functional and radiographic outcome in skeletally immature patients using the modified Grammont surgical technique. Patients Between 1999 and 2004, 65 skeletally immature knees (49 children) were treated with a modified Grammont procedure: an open lateral release and a shift of the patella tendon insertion below the growth plate on the tuberositas tibia, allowing the tendon to medialize. At mean 8 (5.6–11) years after surgery, 58 knees in 43 patients were evaluated by clinical examination, from functional scores (Lysholm, Tegner), and from radiographs of the knees. Results Mean Lysholm score was 82 postoperatively. Tegner score decreased from 6.2 to 5. Eight knees had a single dislocation within 3 months of surgery. 3 knees had repeated late dislocations, all with a high grade of trochlea dysplasia. 6 knees showed mild signs of osteoarthritis. No growth disturbances were observed. Interpretation The modified Grammont technique in skeletally immature patients allows restoration of the distal patella tendon alignment by dynamic positioning. Long-term results showed that there were no growth disturbances and that there was good functional outcome. However, patients with a high grade of trochlea dysplasia tended to re-dislocate. PMID:23039166

2012-01-01

90

Anterior Cruciate Ligament Reconstruction: Clinical Outcomes of Patella Tendon and Hamstring Tendon Grafts  

PubMed Central

An injury to the ACL can result in significant functional impairment. It has been estimated that more than 100,000 new ACL injuries occur each year. Surgeons employ numerous techniques for reconstruction of the ACL. Of critical importance is the source of the graft to replace the damaged ACL. The graft choices include autografts (the patient's own tissue), allografts (donor tendon), and synthetic/prosthetic ligaments. Tissue harvest sites for autografting include the middle third of the patella tendon, the quadriceps tendon, semitendinosus tendon, gracilis tendon, iliotibial band, tensor fascia lata, and the Achilles tendon. Selection of the type of graft material is predicated upon the tissue's ability to tolerate high levels of stress. Likewise, the clinical presentation and functional outcome is related to the graft material selected. This manuscript specifically examined the patella tendon and hamstring tendon grafts. Numerous manuscripts that studied the outcomes of these graft materials were compiled to help the clinician appreciate the advantages and disadvantages of each of the graft materials. Outcome measures such as thigh circumference, knee range of motion, isokinetic strength, knee stability, pain, and vertical jump/1-leg hop were incorporated. The purpose of this manuscript was to compare and contrast the clinical presentation of patients who underwent an ACL reconstruction using the patella tendon versus the hamstring tendons. This information can be valuable to the clinician when considering the rehabilitation protocol after ACL reconstruction. PMID:24701126

Gulick, Dawn T.; Yoder, Heather N.

2002-01-01

91

Osteomyelitis of the patella: ensure a high index of suspicion and beware the negative aspirate.  

PubMed

We report the case of a 33-year-old man who presented several times to healthcare professionals over a 6-week period with a painful swollen right knee. He had a history of chronic osteomyelitis of the left femur and had recently stopped taking suppressive antibiotics. A joint aspirate did not demonstrate any organisms. On subsequent review by the orthopaedic team MRI was performed which revealed an isolated area of osteomyelitis and an abscess in his right patella. He underwent arthrotomy, debridement and irrigation of the joint alongside antibiotic treatment. We highlight this case, as isolated osteomyelitis of the patella is a rare condition, especially in adults. In addition, the presenting features of osteomyelitis of the patella are varied and joint fluid aspirates often do not reveal an organism. This case therefore aims to raise an awareness of this condition and thereby ensure a high index of suspicion when symptoms or signs are present and inform clinicians of the investigative steps in order to avoid a delay in diagnosis as seen in this case. PMID:25320263

Berg, Andrew James; Killen, Maire-Clare; Chauhan, Amit; Bhatia, Chandra

2014-01-01

92

Anterior cruciate ligament reconstruction. Bone-patella tendon-bone versus semitendinosus anatomic reconstruction.  

PubMed

In this article, the long term (2-10 years; mean, 4.8 years) followup results of two reconstructive procedures for the anterior cruciate ligament are compared. The bone-patella tendon-bone (with interference fit fixation) was performed on 69 knees, and the semitendinosus anatomic reconstruction was performed on 68 knees, in a population of 76 men and 52 women (age range, 15-60 years; average, 31 years). The patients in the two groups showed no difference in subjective results or activity level and no significant difference to manual testing. The semitendinosus procedure group had a slightly higher KT manual maximum failure rate than the patella tendon group (17% versus 11%). Arthrometric stability did not show deterioration, but patient satisfaction decreased in those patients who had meniscectomies. Both procedures showed satisfactory results during the long term followup. However, if the secondary restraints are compromised, the stiffer bone-patella tendon-bone construct is preferred for reconstruction of the chronic anterior cruciate ligament deficient knee. PMID:9269157

Feagin, J A; Wills, R P; Lambert, K L; Mott, H W; Cunningham, R R

1997-08-01

93

A Tale of Two Limpets (Patella vulgata and Patella stellaeformis): Evaluating a New Proxy for Late Holocene Climate Change in Coastal Areas  

NASA Astrophysics Data System (ADS)

Shells of the European limpet, Patella vulgata, from Late Holocene archaeological deposits potentially contain critical information about climate change in coastal areas. Before deciphering climate information preserved in these zooarchaeological records, we studied the controls on oxygen isotope ratios (?18O) in modern specimens. We tested the hypothesis that P. vulgata precipitates its shell in isotopic equilibrium with ambient water by comparing ?18OSHELL with expected values. Expected ?18OSHELL was constructed using the calcite-water fractionation equation, observed sea surface temperature (SST), and assuming ?18OWATER is +0.10‰ (VSMOW). Comparison between expected and measured ?18OSHELL revealed a +1.51±0.21‰ (VPDB) offset from expected values. Consequently, estimated SST calculated from ?18OSHELL was 6.50±2.45°C lower than observed SST. However, because the offset was relatively uniform, an adjustment can be made to account for this predictable vital effect and past SST can be reliably reconstructed. To further investigate the source of offset in this genus, we analyzed a fully marine tropical species (Patella stellaeformis) to minimize seasonal variation in environmental factors that influence ?18OSHELL. P. stellaeformis was evaluated to determine whether it has a similar offset from equilibrium as P. vulgata. We tested the hypotheses that: (1) ?18OSHELL in tropical species also displays vital effects; and (2) the offset from equilibrium (if any) would be constant and predictable. Our results indicated: (1) aragonite comprises most of P. stellaeformis' shell; and (2) ?18OSHELL is statistically indistinguishable from expected values calculated using the aragonite-water fractionation equation (Kolmogorov-Smirnov test statistic=0.61, D0.05[56, 57]=1.36) in contrast with our observations in P. vulgata. Differences in mineralogy or growth rates at different latitudes may play a role in mechanisms that influence vital effects.

Fenger, T. L.; Surge, D. M.; Schoene, B. R.; Carter, J. G.; Milner, N.

2006-12-01

94

Effect of femoral component design on unresurfaced patellas in knee arthroplasty.  

PubMed

Three total knee designs were evaluated to test the hypothesis that femoral component design affects the clinical and mechanical functions of the unresurfaced patella after total knee arthroplasty. Patients with the Ortholoc II, Advantim, and Profix femoral components were followed up for as many as 14 years and revision rate, anterior knee pain, and generalized knee pain were compared. A laboratory protocol was devised to evaluate pressure in the patellofemoral joint of knees from cadavers with a pressure-sensitive transducer using the same three designs at various degrees of knee flexion. Thirty Ortholoc II knee components were followed up for 14 years. Nineteen patients (63%) had severe anterior knee pain and 15 patients (50%) had reoperation to resurface the patella within 2 years. Two hundred one patients (222 knees) with Advantim components were followed up for 10 years and 305 patients (330 knees) with Profix components were followed up for 5 years. No patients with these two knee designs had severe anterior knee pain or reoperation for patellar resurfacing. A significantly higher rate of mild anterior knee pain was seen in the patients with Advantim components than in the patients with Profix components. No apparent relationship was seen between the severity of patellar wear found at the time of surgery and the incidence of anterior knee pain. Patients with rheumatoid arthritis receiving either the Advantim or Profix knee component performed as well as patients with osteoarthritis when the patella was not resurfaced. Pressure was significantly higher in the patellofemoral joints of the laboratory knee specimens with Ortholoc II components than in the specimens with either the Advantim or Profix components. The specimens with Advantim components had significantly higher pressure than did the specimens with normal knees, and the specimens with Profix components differed little from those with normal knees. PMID:12771830

Whiteside, Leo A; Nakamura, Takashi

2003-05-01

95

Fracture of highly cross-linked all-polyethylene patella after total knee arthroplasty.  

PubMed

Recent advances in polyethylene fabrication have led to the introduction of highly cross-linked polyethylene tibial and patellar components for use in total knee arthroplasty (TKA) with the goal of reducing wear-related osteolysis. However, some reports suggest decreased mechanical strength as a result of the additional thermal and sterilization treatments in the manufacturing of implants. Complications related to the patella are among the most common causes of failure in TKA, but patellar component fracture is rare. The authors report a case of a highly cross-linked all-polyethylene patellar component that failed as a result of fracture in vivo in a patient 3 years after TKA. PMID:21446631

Hambright, Dustin S; Watters, Tyler Steven; Kaufman, Adam M; Lachiewicz, Paul F; Bolognesi, Michael P

2010-12-01

96

Stifle disorders: cranial cruciate ligament, meniscus, upward fixation of the patella.  

PubMed

Stifle injury in cattle can be a debilitating condition. Stifle injuries often present as nonspecific lameness with subtle clinical signs. Physical examination with manipulation of the stifle joint, radiographs, and analysis of the joint fluid can help to make a diagnosis. Cranial cruciate and collateral ligament injuries are among the most common traumatic injuries of the stifle joint. Although the prognosis is guarded, better success and less degenerative change are expected with early diagnosis and treatment. Meniscal injuries and upward fixation of the patella are less commonly diagnosed, but their clinical signs, treatment, and prognosis are discussed in this article. PMID:24534669

Pentecost, Rebecca; Niehaus, Andrew

2014-03-01

97

Recurrent Dislocation of the Patella in Kabuki Make-Up Syndrome  

PubMed Central

Two patients with Kabuki make-up syndrome with bilateral recurrent dislocation of the patella are presented. They had generalized ligamentous laxity and patellofemoral dysplasia. Both developed patellar dislocation in adolescence and required surgery, with medial transfer of the tibial tuberosity associated with vastus medialis plasty (Insall technique). One postoperative complication occurred in one case: a nondisplaced tibia fracture at the sixth postoperative week that healed with conservative means. Final results were good in both cases. Good surgical results can be achieved in patellar dislocation in patients with Kabuki syndrome. PMID:23320229

Rouffiange, Lucie; Dusabe, Jean-Paul; Docquier, Pierre-Louis

2012-01-01

98

Host Control of Symbiont Natural Product Chemistry in Cryptic Populations of the Tunicate Lissoclinum patella  

PubMed Central

Natural products (secondary metabolites) found in marine invertebrates are often thought to be produced by resident symbiotic bacteria, and these products appear to play a major role in the symbiotic interaction of bacteria and their hosts. In these animals, there is extensive variation, both in chemistry and in the symbiotic bacteria that produce them. Here, we sought to answer the question of what factors underlie chemical variation in the ocean. As a model, we investigated the colonial tunicate Lissoclinum patella because of its rich and varied chemistry and its broad geographic range. We sequenced mitochondrial cytochrome c oxidase 1 (COXI) genes, and found that animals classified as L. patella fall into three phylogenetic groups that may encompass several cryptic species. The presence of individual natural products followed the phylogenetic relationship of the host animals, even though the compounds are produced by symbiotic bacteria that do not follow host phylogeny. In sum, we show that cryptic populations of animals underlie the observed chemical diversity, suggesting that the host controls selection for particular secondary metabolite pathways. These results imply novel approaches to obtain chemical diversity from the oceans, and also demonstrate that the diversity of marine natural products may be greatly impacted by cryptic local extinctions. PMID:24788869

Kwan, Jason C.; Tianero, Ma. Diarey B.; Donia, Mohamed S.; Wyche, Thomas P.; Bugni, Tim S.; Schmidt, Eric W.

2014-01-01

99

Plateau-patella angle in evaluation of patellar height after total knee arthroplasty.  

PubMed

The plateau-patella angle (PPA) has been proposed as a new and simpler method to describe patellar height. This method has not been used or validated in knees following total knee arthroplasty (TKA). A modified PPA (mPPA) was developed for use in this population. The method was validated by determining the interobserver and intraobserver reliability of the technique in 50 consecutive patients compared to three well-described methods of describing patellar height after TKA. Three observers then evaluated the mPPA of 297 post-operative radiographs to describe a normal range after TKA for a given technique and implant. The interobserver reliability was the highest for the mPPA compared to the other methods. The mean mPPA for the entire cohort was 21.06, 20.49, and 19.94 for the three observers. The modified plateau-patella angle is a reliable way to evaluate patellar height in patients who have undergone total knee arthroplasty. PMID:24612739

Robin, Brett N; Ellington, Matthew D; Jupiter, Daniel C; Allen, Bryce C

2014-07-01

100

Basic kinematics and biomechanics of the patellofemoral joint part 2: the patella in total knee arthroplasty.  

PubMed

Patellar and femoral component in total knee arthroplasty are inextricably linked as a functional unit. The configuration of this unit has been a matter of ongoing debate, and the myriad of different patellar and femoral components currently available reflect the lack of consensus with respect to the ideal design. One of the major challenges is to overcome the biomechanical disadvantages of a small contact area through which high contact pressures are transferred, making this mechanical construct the weakest part of the prosthetic knee. Contact areas are highly dependent on the congruency of the patellofemoral joint articulation, and are significantly smaller for dome shaped patellar components compared to those of more anatomic designs. However, when exposed to 3-dimensional movements, the contact areas of the dome shaped patella are significantly greater, indicating enhanced forgiveness regarding patellar malpositioning. Although contact stresses, a function of implant design and surface conformity, can reach levels far beyond the yield strength of UHMWPE, catastrophic failure of resurfaced patellar components, commonly seen in metal backed patellae, fashionable in the 1980s, has rarely been observed since. Although plastic deformation and wear of UHMWPE continue to represent a problem, in the absence of suitable alternatives polyethylene remains the bearing surface of choice. The appreciation of the consequences of the mechanical environment on the behaviour of the patellofemoral joint is of particular importance in the endeavour to develop knee replacement systems which provide satisfactory function together with clinical long-term success. PMID:22523923

Schindler, Oliver S

2012-02-01

101

Coccidiomycosis infection of the patella mimicking a neoplasm - two case reports  

PubMed Central

Background Coccidioidomycosis is an endemic fungal infection in the southwestern of United States. Most infections are asymptomatic or manifest with mild respiratory complaints. Rare cases may cause extrapulmonary or disseminated disease. We report two cases of knee involvement that presented as isolated lytic lesions of the patella mimicking neoplasms. Case Presentation The first case, a 27 year-old immunocompetent male had progressive left anterior knee pain for four months. The second case was a 78 year-old male had left anterior knee pain for three months. Both of them had visited general physicians without conclusive diagnosis. A low attenuation lytic lesion in the patella was demonstrated on their image studies, and the initial radiologist’s interpretation was suggestive of a primary bony neoplasm. The patients were referred for orthopaedic oncology consultation. The first case had a past episode of pulmonary coccioidomycosis 2 years prior, while the second case had no previous coccioidal infection history but lived in an endemic area, the central valley of California. Surgical biopsy was performed in both cases due to diagnostic uncertainty. Final pathologic examination revealed large thick walled spherules filled with endospores establishing the final diagnosis of extrapulmonary coccidioidomycosis. Conclusions Though history and laboratory findings are supportive, definitive diagnosis still depends on growth in culture or endospores identified on histology. We suggest that orthopaedic surgeons and radiologists keep in mind that chronic fungal infections can mimic osseous neoplasm by imaging. PMID:24548622

2014-01-01

102

Metallothionein concentrations in a population of Patella aspera: variation with size.  

PubMed

The determination of metallothionein (MT) concentrations in species with different feeding habits is important from the ecotoxicological point of view because it provides a better understanding of the role of these proteins in metal uptake pathways. The main objective was study the variation of MT and metal (Cd, Cu and Zn) concentrations with size and weight in the limpets Patella aspera. In addition investigate the relationship between MT and metal concentrations in limpets from different metal load environments of the south coast of Portugal with the aim to use MT in P. aspera as a biomarker of metal exposure. MT concentrations in the whole soft tissues of P. aspera increased with size and weight while metals decrease with size and weight. MT concentrations showed no significant relationship with Cd or Cu concentrations in the limpets from the South Portuguese Coast. However, a negative exponential relationship detected between MT and Zn concentrations suggest that Zn bound to MT might be displaced by Cd or Cu ions. The ability of limpets to store both Cd and Cu bound to MT may be responsible for the tolerance of this species to contaminated environments. The relationship between MT concentrations and Zn indicates that MT seems to play a minor role in binding Zn in Patella species. PMID:12493193

Bebianno, M J; Cravo, A; Miguel, C; Morais, S

2003-01-01

103

Life-history patterns of populations of the limpet Patella granularis : the dominant roles of food supply and mortality rate  

Microsoft Academic Search

Rates of algal production were measured at 6 rocky intertidal sites on the southwestern Cape coast, South Africa, where populations of the limpet Patella granularis occur. Rates of algal production and limpet mortality were recorded at each site and both factors affected limpet reproductive fitness. Limpet growth rates and biomass at different sites were significantly correlated with rates of algal

A. L. Bosman; P. A. R. Hockey

1988-01-01

104

Spontaneous patella fracture associated with anterior tibial tubercle pseudarthrosis in a revised knee replacement following knee Arthrodesis  

PubMed Central

Background Conversion of a knee arthrodesis to a Total Knee Arthroplasty is an uncommon procedure. Revision Total Knee Arthroplasty in this setting presents the surgeon with a number of challenges including the management of the extensor mechanism and patella. Case presentation We describe a unique case of a 69 years old Caucasian man who underwent a revision Total Knee Arthroplasty using a tibial tubercle osteotomy after a previous conversion of a knee arthrodesis without patella resurfacing. Unfortunately 9 months following surgery a tibial tubercle pseudarthrosis and spontaneous patella fracture occurred. Both were managed with open reduction and internal fixation. At 30 months follow-up the tibial tubercle osteotomy had completely consolidated while the patella fracture was still evident but with no signs of further displacement. The patient was completely satisfied with the outcome and had a painless range of knee flexion between 0-95°. Conclusions We believe that patients undergoing this type of surgery require careful counseling regarding the risk of complications both during and after surgery despite strong evidence supporting improved functional outcomes. PMID:24195600

2013-01-01

105

The Effect of Alignment of the Implant on Fractures of the Patella after Condylar Total Knee Arthroplasty  

Microsoft Academic Search

The results in thirty-six knees that had a fracture of the patella after a total condylar arthro- plasty were reviewed, and were analyzed according to the type of fracture and the alignment of the implant and the limb. Most of the fractures occurred two years or less after the initial operation. Fourteen knees were rated fair or poor and twenty-two,

HARRY E. FIGGIE; VICTOR M. GOLDBERG; MARK P. FIGGIE; ALLAN E. INGLIS; MICHAEL KELLY; MARK SOBEL

1989-01-01

106

Patellar Shape-Memory Fixator for the Treatment of Comminuted Fractures of the Inferior Pole of the Patella  

NASA Astrophysics Data System (ADS)

Comminuted and displaced fractures of the inferior pole of the patella are not easy to reduce and it is difficult to fix the fragments soundly enough to allow early movement of the knee. The purpose of this study is to evaluate the clinical effectiveness of the internal fixation technique with Patellar Shape-Memory Fixator (PSMF) in acute comminuted fractures of the inferior pole of the patella. We retrospectively studied 25 patients with comminuted fractures of the inferior pole of the patella who were treated with PSMF and followed up for a mean period of 26 months (14 to 60). All the fractures healed at a mean of 6 weeks (5 to 7). The mean grading at the final follow-up was 29.5 points (27 to 30) using the Bostman score, with no observable restriction of movement. No breakage of the PSMF or infection occurred. No delayed union, nonunion, and infection were seen. This technique preserved the length of the patella, reduced the comminuted fragments of the inferior pole and avoided long-term immobilization of the knee.

Liu, Xin-Wei; Shang, Hui-Juan; Xu, Shuo-Gui; Wang, Zhi-Wei; Zhang, Chun-Cai; Fu, Qing-Ge

2011-07-01

107

Bioaccumulation of metals in the soft tissue of Patella aspera: Application of metal\\/shell weight indices  

Microsoft Academic Search

Patella aspera limpets were taken from a marine clean site (MCS) and an estuarine contaminated site (ECS). The concentrations of Fe, Mn, Zn, Cu, Cd, Ni and Co were determined individually over the available size range. Since there were significant differences in the soft tissue weight between populations, but shell characteristics were similar (length and weight), metal\\/shell weight indices (MSI)

A. Cravo; M. J. Bebianno

2005-01-01

108

Ultrashort-Echo Time MR Imaging of the Patella with Bicomponent Analysis: Correlation with Histopathologic and Polarized Light Microscopic Findings  

PubMed Central

Purpose: To correlate short and long T2* water fractions, derived from ultrashort–echo time (TE) magnetic resonance (MR) imaging, with semiquantitative histopathologic and polarized light microscopic (PLM) assessment of human cadaveric patellae cartilage. Materials and Methods: Twenty human cadaveric patellae were evaluated by using ultrashort-TE imaging, spin-echo imaging, histopathologic analysis, and PLM, with institutional review board approval. Short and long T2* water components were evaluated for each patella by using bicomponent fitting of ultrashort-TE signal decay. Four to six regions of interest (ROIs) within each patella were chosen for correlation between ultrashort-TE bicomponent analysis, histopathologic grading (Mankin score), and PLM grading (Vaudey score). Results: Ultrashort-TE imaging with bicomponent analysis showed two distinct water components with a short T2* and a longer T2* in all patellae. ROI analysis showed that the short T2* fraction was correlated significantly with the Mankin (? = 0.66, P < .001) and Vaudey (? = 0.68, P < .001) scores. The Mankin scores were weakly positively correlated with T2 (? = 0.28, P = .13) and short T2* (? = 0.24, P = .14) but were negatively correlated with long T2* (? = ?0.55, P < .01). The Vaudey scores were weakly positively correlated with T2 (? = 0.18, P = .16) and short T2* (? = 0.22, P = .14) but were negatively correlated with long T2* (? = ?0.55, P < .01). Conclusion: Short T2* water fraction derived from ultrashort-TE imaging with bicomponent analysis correlates significantly with both the Mankin and Vaudey scores and may serve as a biomarker of cartilage degeneration. ©RSNA, 2012 PMID:22653187

Pauli, Chantal; Bae, Won C.; Lee, Michael; Lotz, Martin; Bydder, Graeme M.; D'Lima, Darryl L.; Chung, Christine B.

2012-01-01

109

Quantitative PIXE and PIGME analysis of milligram samples of biomineralized tissue in the limpet Patella vulgata  

NASA Astrophysics Data System (ADS)

Procedures have been developed to determine, by thick target PIXE and PIGME, the quantitative elemental composition of biological samples with a mass of approximately 1 mg. Systems of particular interest are the biomineralized tissues of chitons and limpets, marine invertebrates of global distribution whose radula teeth and associated tissue contain, variously, inorganic components at different stages of mineralization, e.g. Fe, Ca, P, F, Si, Cu. For the biomineralized teeth and tissue in the limpet Patella vulgata the content of Fe, Ca and P increases rapidly at an early stage of mineralization, while the Si content increases somewhat later. In fully mineralized teeth, the Fe and Si contents are comparable. These data are compared with previous results (Trends Biochem. Sci. 10 (1985) 6) obtained using the Oxford scanning proton microprobe.

Kim, K.-S.; Webb, J.; Macey, D. J.; Cohen, D. D.

1987-03-01

110

Medial Patellofemoral Ligament Reconstruction: A New Technique for Graft Fixation at the Patella Without Implants  

PubMed Central

Patellofemoral instability is a complex disorder that is often accompanied by insufficiency or tearing of the medial patellofemoral ligament. Over the past few years, several techniques using free tendon grafts for medial patellofemoral ligament reconstruction have become popular because of their reproducible effect and good outcome. Whereas most surgeons prefer femoral fixation of the graft using an interference screw, the possibilities of patellar fixation are numerous. All of the different techniques have their own advantages and pitfalls. We describe a technique in which we drill 2 blind-ending tunnels (1 cm) at the medial aspect of the patella, where the doubled graft (not the free ends) is pulled in and fixed. By using a special technique for shuttling the sutures, there is no need for an additional skin incision and no need for implants, allowing very secure graft fixation without a relevant risk of fracture. PMID:24749029

Shafizadeh, Sven; Balke, Maurice

2014-01-01

111

Treatment of habitual dislocation of patella in an adult arthritic knee  

PubMed Central

Habitual dislocation of the patella (HDP) is a common presentation in pediatric age unlike adults. Many surgical procedures using proximal realignment and distal realignment have been reported to treat HDP in children with satisfactory results. However, late presentation of habitual patellar dislocation with osteoarthritis is rare and treatment plan has not yet been established. We present a case of neglected iatrogenic habitual patellar dislocation with osteoarthritis in a 50-year-old woman. Two-staged procedure was planned, first with patellar realignment and later with definitive total knee arthroplasty. Quadricepsplasty, medial patello-femoral ligament reconstruction, lateral release and tibial tuberosity transfer was done as primary procedure and total knee arthroplasty, which was planned as secondary procedure, was deferred as the patient improved functionally. PMID:24379472

Reddy, Raghuveer K; Kondreddi, Vamsi

2013-01-01

112

Biomechanics of the Patello-Femoral Joint. Part I: A Study of the Contact and the Congruity of the Patello-Femoral Compartment and Movement of the Patella  

Microsoft Academic Search

Techniques are described for studying the pattern of contact and congruence of the patello-femoral joint, and the movement of the patella at different angles of knee flexion. The study is carried out on cadaveric knee specimens.

K Fujikawa; B B Seedhom; V Wright

1983-01-01

113

Associations of Bone Mineral Density and Lead Levels in Blood, Tibia, and Patella in Urban-Dwelling Women  

PubMed Central

Objective The objective of this study was to evaluate the relations between bone mineral density (BMD) and lead in blood, tibia, and patella and to investigate how BMD modifies these lead biomarkers in older women. Design In this study, we used cross-sectional analysis. Participants We studied 112 women, 50–70 years of age, including both whites and African Americans, residing in Baltimore, Maryland. Measurements We measured lumbar spine BMD, blood and bone lead by dual energy X-ray absorptiometry, anodic stripping voltammetry, and 109Cd-induced K-shell X-ray fluorescence, respectively. We measured vitamin D receptor and apolipoprotein E (APOE) genotypes using standard methods. Results Mean (± SD) BMD and lead levels in blood, tibia, and patella were 1.02 ± 0.16 g/cm2, 3.3 ± 2.2 ?g/dL, 19.7 ± 13.2 ?g/g, and 5.7 ± 15.3 ?g/g, respectively. In adjusted analysis, higher BMD was associated with higher tibia lead levels (p = 0.03). BMD was not associated with lead levels in blood or patella. There was evidence of significant effect modification by BMD on relations of physical activity with blood lead levels and by APOE genotype on relations of BMD with tibia lead levels. There was no evidence that BMD modified relations between tibia lead or patella lead and blood lead levels. Conclusions We believe that BMD represents the capacity of bone that can store lead, by substitution for calcium, and thus the findings may have relevance for effect-size estimates in persons with higher BMD. Relevance to clinical practice The results have implications for changes in lead kinetics with aging, and thus the related risk of health effects associated with substantial early- and midlife lead exposure in older persons. PMID:18560535

Theppeang, Keson; Glass, Thomas A.; Bandeen-Roche, Karen; Todd, Andrew C.; Rohde, Charles A.; Links, Jonathan M.; Schwartz, Brian S.

2008-01-01

114

The postoperative patella height: a comparison of additive and subtractive high tibial osteotomy in correcting the genu varum  

Microsoft Academic Search

Introduction  Intraligamentary correctional operations like a high tibial osteotomy were performed in genua valga to prevent later medial\\u000a gonarthrosis especially in younger patients. An unwanted effect of this method seems to be the inferiorization of the patella.\\u000a This is feared because of the complications in case of subsequent alloarthroplasty. Besides the classical Coventry method\\u000a as a subtractive osteotomy the hemicallotasis has

Frank Schiedel; Alexandra Probst; Tim C. Buller; Robert Rödl

2009-01-01

115

Influence of Gradual Elongation to the Patella Tendon Insertion in Rabbits  

PubMed Central

The purpose of this study was to examine the histological changes at the patella tendon (PT) insertion site under gradual elongation in rabbits. Gradual elongation of the PT was performed using external fixation for 4 weeks, with a lengthening speed of 0.5 mm/day (elongation group; n = 24). Rabbits in the sham group underwent the same surgical procedure without gradual elongation (sham group; n = 24). Eight animals were sacrificed 1, 2 and 4 weeks after surgery in each group, respectively. Average thicknesses of stained glycosaminoglycan (GAGs) areas by Safranin-O staining in the total cartilage layer and the uncalcified fibrocartilage layer in the elongation group were significantly higher than that in the sham group at 4 weeks (p < 0.05) and that in the intact PT group (n = 6, p < 0.05). In the elongation group, the peak in the average thicknesses of the stained GAGs areas in the total cartilage layer and the uncalcified fibrocartilage layer were observed at 4 weeks. Gradual elongation of PT insertion significantly affected the increase in the average thicknesses of the stained GAGs areas in the cartilage layer especially in the uncalcified fibrocartilage layer at 4 weeks in rabbits. Clinically, insertions of tendon and ligament can extend during gradual elongation using external fixation more than 4 weeks after the operation. PMID:25153635

Mutsuzaki, Hirotaka; Nakajima, Hiromi; Wadano, Yasuyoshi; Watanabe, Shintarou; Sakane, Masataka

2014-01-01

116

Medieval Warm Period Archives Preserved in Limpet Shells (Patella Vulgata) From Viking Deposits, United Kingdom  

NASA Astrophysics Data System (ADS)

The Medieval Warm Period (700-1100 YBP) represents a recent period of warm climate, and as such provides a powerful comparison to today's continuing warming trend. However, the spatial and temporal variability inherent in the Medieval Warm Period (MWP) makes it difficult to differentiate between global climate trends and regional variability. The continued study of this period will allow for the better understanding of temperature variability, both regional and global, during this climate interval. Our study is located in the Orkney Islands, Scotland, which is a critical area to understand climate dynamics. The North Atlantic Oscillation and Gulf Stream heavily influence climate in this region, and the study of climate intervals during the MWP will improve our understanding of the behavior of these climate mechanisms during this interval. Furthermore, the vast majority of the climate archive has been derived from either deep marine or arctic environments. Studying a coastal environment will offer valuable insight into the behavior of maritime climate during the MWP. Estimated seasonal sea surface temperature data were derived through isotopic analysis of limpet shells (Patella vulgata). Analysis of modern shells confirms that growth temperature tracks seasonal variation in ambient water temperature. Preliminary data from MWP shells record a seasonal temperature range comparable to that observed in the modern temperature data. We will extend the range of temperature data from the 10th through 14th centuries to advance our knowledge of seasonal temperature variability during the late Holocene.

Mobilia, M.; Surge, D.

2008-12-01

117

A Viscoelastic Constitutive Model Can Accurately Represent Entire Creep Indentation Tests of Human Patella Cartilage  

PubMed Central

Cartilage material properties provide important insights into joint health, and cartilage material models are used in whole-joint finite element models. Although the biphasic model representing experimental creep indentation tests is commonly used to characterize cartilage, cartilage short-term response to loading is generally not characterized using the biphasic model. The purpose of this study was to determine the short-term and equilibrium material properties of human patella cartilage using a viscoelastic model representation of creep indentation tests. We performed 24 experimental creep indentation tests from 14 human patellar specimens ranging in age from 20 to 90 years (median age 61 years). We used a finite element model to reproduce the experimental tests and determined cartilage material properties from viscoelastic and biphasic representations of cartilage. The viscoelastic model consistently provided excellent representation of the short-term and equilibrium creep displacements. We determined initial elastic modulus, equilibrium elastic modulus, and equilibrium Poisson’s ratio using the viscoelastic model. The viscoelastic model can represent the short-term and equilibrium response of cartilage and may easily be implemented in whole-joint finite element models. PMID:23027200

Pal, Saikat; Lindsey, Derek P.; Besier, Thor F.; Beaupre, Gary S.

2013-01-01

118

Partitioning of trace metals between soft tissues and shells of Patella aspera.  

PubMed

This paper describes the partitioning of iron, manganese, zinc, copper, cadmium, cobalt, nickel and lead between the soft tissues and the shells of the gastropod mollusc Patella aspera. Specimens of the limpet P. aspera were collected from a clean coastal marine site (CMS) and from an estuarine contaminated site (ECS) on the south coast of Portugal. Fe and Zn concentrations were significantly lower on both populations and less variable in the shells than in the soft tissues. In contrast Mn concentrations were higher in the shells than in the soft tissues at ECS. The partitioning factor (PF), defined as the ratio between the mean metal concentrations in soft tissues and in the shells, was maximum for iron and minimum for manganese. Between the soft tissues and the shells, only manganese at ECS recorded a significant relationship between metal concentrations, suggesting that the mechanism that controls the accumulation of this essential metal in both tissues was different from the others. From the obtained data, in biomonitoring sewage contamination studies, shells of P. aspera can be considered as a good indicator for Mn while the soft tissues for Zn. As copper, cadmium, nickel and cobalt concentrations were much higher in the soft tissues than in the shells (< 0.1 microg g(-1)), this indicates that the shells were not a good indicator for these metals because they do not reflect the environmental bioavailability as do the soft tissues. PMID:14664868

Cravo, A; Bebianno, M J; Foster, P

2004-03-01

119

Minor and trace elements in the shell of Patella aspera (Röding 1798).  

PubMed

Specimens of the limpet Patella aspera were collected from a clean, coastal marine site and a contaminated estuary on the south coast of Portugal. The shells were analysed individually for their minor (Mg, Sr) and trace element (Fe, Mn, Zn) content. Mean concentrations of these elements in the shell of P. aspera were 4651, 1318, 35.8, 29.9 and 5.5 microg g(-1), respectively. The elemental concentrations exhibited both a marked intra- and inter-population variability. Despite the variability within individual populations, significant differences in the trace element composition were apparent between the shells taken from the two sites. Small shells (< 2 g) provided the best resolution between sites for both manganese and iron. Differences in zinc were best resolved for larger shells. The shell of P. aspera has an extraordinarily high magnesium concentration, which is insensitive to gross salinity differences, and a trace metal assemblage that can be interpreted in terms of environmental exposure. On these grounds, it is recommended that the shell of P. aspera is a tissue for potential use in environmental trace metal monitoring. PMID:12220116

Cravo, A; Foster, P; Bebianno, M J

2002-09-01

120

AN ELECTRON MICROSCOPE STUDY OF THE CYTOLOGY OF THE PROTOZOAN EUPLOTES PATELLA  

PubMed Central

1. Structurally the "sensory bristles" in Euplotes patella are typical cilia, but no ciliary rootlets connect their bases. 2. The "neuromotor fibrils" are composed of filaments 21 mµ in diameter. At the point of junction of the filaments with the peripheral ciliary fibrils a granular structure 65 to 90 mµ in diameter is seen which has dense central and peripheral zones separated by a less dense layer. Information on the interconnection of organelles is expanded. 3. A system of subpellicular fibrils is described. The external fibrillar system described by others could not be found. 4. The motorium is shown to be a mass of intertwining rootlet filaments. 5. The micronucleus is shown to have a spongy, dense material in a less dense material, all of which is surrounded by a double-layered membrane. 6. The double-layered macronuclear membrane contains annuli whose outside diameter is 70 mµ; the macronuclear bodies are sometimes closely applied to the membrane. In the macronuclear reorganization bands, the solution plane is a fine network, while the reconstruction plane is devoid of structure at the level of resolution observed. 7. The mitochondria are composed of tubules, only occasionally oriented, usually embedded in a surrounding material of lower density. 8. Microbodies whose diameters are 250 to 350 mµ are frequently observed in close association with mitochondrial surfaces. 9. The food vacuoles, contractile vacuoles, and ciliary vacuoles are bounded by single-layered membranes. In the food vacuoles, the bacteria are surrounded by membranes individually or in small groups. 10. Cytoplasmic rods localized in the oral region, and cytoplasmic granules dispersed at random, are described. No typical ergastoplasm, endoplasmic reticulum, or Golgi material was observed. PMID:13481030

Roth, L. E.

1957-01-01

121

Quantification of midkine gene expression in Patella caerulea (Mollusca, Gastropoda) exposed to cadmium  

NASA Astrophysics Data System (ADS)

The release of cadmium into many coastal areas represents a threat to ecosystems and human health; cadmium is carcinogenic in mammals and in both marine invertebrates and vertebrates. The use of molluscs to assess the ecologic risk associated with contaminants is strongly recommended on account of their ecological role and on their highly conserved control and regulatory pathways that are often homologous to vertebrate systems. We previously identified a midkine family protein in the limpet Patella caerulea; the midkine is a recently discovered cytokines family with unequivocal informative value on repairing injury and neoplastic processes in mammals. Here we report on midkine ( mdk) and ?-tubulin ( ?-tub) gene expression patterns in P. caerulea exposed to cadmium. Limpets, collected on two occasions from a breakwater at a marina (Tyrrhenian Sea) were exposed to sublethal cadmium concentrations (0.5 and 1 mg l -1 Cd) over a 10-day exposure period. RNA was extracted from the viscera of unexposed and exposed specimens. Real time TaqMan RT-PCR was performed to measure the relative mdk and ?-tub gene expression levels. A remarkable mdk over-expression was observed in all exposed animals with respect to unexposed ones; mdk over-expression was significantly higher in both treatments when compared with un-treatment (mean expression levels: 23- and 38-fold, for 0.5 and 1 mg l -1 Cd treatment, respectively; ANOVA, for both P < 0.01). The study also indicates that the mdk up-regulation was significantly Cd-concentration dependent ( P < 0.05). A significant up-regulation of the constitutive ?-tub gene was also observed in 1 mg l -1 Cd-treated animals (mean expression level: 4-fold; ANOVA, P < 0.05). In conclusion, these data provide the first evidence paving the way for the use of the midkine as a promising new biomarker of effect in the environment risk assessment policy.

Stillitano, Francesca; Mugelli, Alessandro; Cerbai, Elisabetta; Vanucci, Silvana

2007-10-01

122

Eccentric Exercise Protocols for Patella Tendinopathy: Should we Really be Withdrawing Athletes from Sport? A Systematic Review  

PubMed Central

The 2007 review by Visnes and Bahr concluded that athletes with patella tendinopathy should be withdrawn from sport whilst engaging in eccentric exercise (EE) rehabilitation programs. However, deprivation of sport is associated with a number of negative psychological and physiological effects. Withdrawal from sport is therefore a decision that warrants due consideration of the risk/benefit ratio. The aim of this study was to determine whether sufficient evidence exists to warrant withdrawal of athletes from sport during an eccentric exercise rehabilitation program. A systematic review of the literature was performed to identify relevant randomised trials. Data was extracted to determine whether athletes were withdrawn from sport, what evidence was presented to support the chosen strategy and whether this affected the clinical outcome. Seven studies were included. None of these reported high quality evidence to support withdrawal. In addition, three studies were identified in which athletes were not withdrawn from sport and still benefited from EE. This review has demonstrated that there is no high quality evidence to support a strategy of withdrawal from sport in the management of patella tendinopathy. PMID:23248727

Saithna, Adnan; Gogna, Rajiv; Baraza, Njalalle; Modi, Chetan; Spencer, Simon

2012-01-01

123

DIFFERENTIAL CROSS-LINKING AND RADIO-PROTECTIVE EFFECTS OF GENIPIN ON MATURE BOVINE AND HUMAN PATELLA TENDONS  

PubMed Central

Gamma irradiation is a proven sterilization method, but is not widely used on allografts for anterior cruciate ligament (ACL) reconstruction (e.g., patella tendon) due to radiation-induced decreases in mechanical strength. Addressing this drawback would improve the safety and supply of allografts to meet current and future demand. It was hypothesized that genipin-induced collagen cross-linking would increase the tensile modulus of patella tendon tissue such that 5 MRad gamma irradiation would not reduce the tissue mechanical strength below the original untreated values. Optimized genipin treatment increased the tensile modulus of bovine tendons by ~2.4-fold. After irradiation, genipin treated tissue did not significantly differ from native tissue, proving the hypothesis. Optimized genipin treatment of human tendons increased the tensile modulus by ~1.3-fold. After irradiation, both control and genipin-treated tissues possessed ~50–60% of their native tendon modulus, disproving the hypothesis. These results highlight possible age- and species-dependent effects of genipin cross-linking on tendon tissue. Cross-linking of human allografts may be beneficial only in younger donor tissues. Future research is warranted to better understand the mechanisms and applications of collagen cross-linking for clinical use. PMID:22350064

Ng, Kenneth W.; Wanivenhaus, Florian; Chen, Tony; Abrams, Valarian D.; Torzilli, Peter A.; Warren, Russell F.; Maher, Suzanne A.

2013-01-01

124

Nail-Patella Syndrome in Saudi Arabia With New Features and Surgical Procedures: The First Described Study  

PubMed Central

The purpose of this study was to reveal the occurrence of nail-patella syndrome (NPS) in Saudi Arabia together with the detection of abnormal attachment of lateral meniscus in the left knee and new surgical procedures applied to the right and left knee, reported for the first time in this study. This was a case study of a 23-year-old young man presenting with bilateral knee pain, giving way and locking since the age of 15 years. Clinically, most of the NPS features were noted, including ocular problems. The complex features affected both knees, especially the previous attempted surgeries for recurrent dislocation of patellae. Deficient ligaments were reconstructed using the Leeds-Keio ligament, starting with the right knee and continuing with the left knee 6 months later. Early and late follow-up showed favorable outcome of surgery revealed as independent ambulation and stable right and left knees. In conclusion, NPS, although rare, presents a complex problem and unexpected surgical outcome, and we recommend this procedure with close follow-up. PMID:15266233

Juma, Abdullah H. A

2004-01-01

125

Comparison of two tension-band fixation materials and techniques in transverse patella fractures: a biomechanical study.  

PubMed

This study compared the biomechanical properties of 2 tension-band techniques with stainless steel wire and ultra high molecular weight polyethylene (UHMWPE) cable in a patella fracture model. Transverse patella fractures were simulated in 8 cadaver knees and fixated with figure-of-8 and parallel wire configurations in combination with Kirschner wires. Identical configurations were tested with UHMWPE cable. Specimens were mounted to a testing apparatus and the quadriceps was used to extend the knees from 90 degrees to 0 degrees; 4 knees were tested under monotonic loading, and 4 knees were tested under cyclic loading. Under monotonic loading, average fracture gap was 0.50 and 0.57 mm for steel wire and UHMWPE cable, respectively, in the figure-of-8 construct compared with 0.16 and 0.04 mm, respectively, in the parallel wire construct. Under cyclic loading, average fracture gap was 1.45 and 1.66 mm for steel wire and UHMWPE cable, respectively, in the figure-of-8 construct compared with 0.45 and 0.60 mm, respectively, in the parallel wire construct. A statistically significant effect of technique was found, with the parallel wire construct performing better than the figure-of-8 construct in both loading models. There was no effect of material or interaction. In this biomechanical model, parallel wires performed better than the figure-of-8 configuration in both loading regimens, and UHMWPE cable performed similarly to 18-gauge steel wire. PMID:19292214

Rabalais, R David; Burger, Evalina; Lu, Yun; Mansour, Alfred; Baratta, Richard V

2008-02-01

126

The "Fungia patella group" (Scleractinia, Fungiidae) revisited with a description of the mini mushroom coral Cycloseris boschmai sp. n.  

PubMed Central

Abstract The recent taxonomic history of extant free-living Cycloseris species is briefly reviewed, resulting in the description of Cycloseris boschmai sp. n. (Scleractinia, Fungiidae) and a discussion on the validity of two other recently described species. Some Cycloseris species were previously considered to belong to the Fungia patella group, which also concerned misidentified museum specimens that actually belong to the new species. Other specimens of C. boschmai sp. n. were photographed and collected in the course of 30 years of fieldwork. The new mushroom coral is compared with other free-living Cycloseris species by means of an identification key. With a maximum diameter of 50 mm, it is the smallest free-living mushroom coral discovered so far. It can also be distinguished by its large primary order costae and variable colouration. Its distribution range is limited to the Coral Triangle, where it can be observed as an uncommon species on lower reef slopes. PMID:24493954

Hoeksema, Bert W.

2014-01-01

127

Microenvironmental Ecology of the Chlorophyll b-Containing Symbiotic Cyanobacterium Prochloron in the Didemnid Ascidian Lissoclinum patella  

PubMed Central

The discovery of the cyanobacterium Prochloron was the first finding of a bacterial oxyphototroph with chlorophyll (Chl) b, in addition to Chl a. It was first described as Prochloron didemni but a number of clades have since been described. Prochloron is a conspicuously large (7–25??m) unicellular cyanobacterium living in a symbiotic relationship, primarily with (sub-) tropical didemnid ascidians; it has resisted numerous cultivation attempts and appears truly obligatory symbiotic. Recently, a Prochloron draft genome was published, revealing no lack of metabolic genes that could explain the apparent inability to reproduce and sustain photosynthesis in a free-living stage. Possibly, the unsuccessful cultivation is partly due to a lack of knowledge about the microenvironmental conditions and ecophysiology of Prochloron in its natural habitat. We used microsensors, variable chlorophyll fluorescence imaging and imaging of O2 and pH to obtain a detailed insight to the microenvironmental ecology and photobiology of Prochloron in hospite in the didemnid ascidian Lissoclinum patella. The microenvironment within ascidians is characterized by steep gradients of light and chemical parameters that change rapidly with varying irradiances. The interior zone of the ascidians harboring Prochloron thus became anoxic and acidic within a few minutes of darkness, while the same zone exhibited O2 super-saturation and strongly alkaline pH after a few minutes of illumination. Photosynthesis showed lack of photoinhibition even at high irradiances equivalent to full sunlight, and photosynthesis recovered rapidly after periods of anoxia. We discuss these new insights on the ecological niche of Prochloron and possible interactions with its host and other microbes in light of its recently published genome and a recent study of the overall microbial diversity and metagenome of L. patella. PMID:23226144

Kuhl, Michael; Behrendt, Lars; Trampe, Erik; Qvortrup, Klaus; Schreiber, Ulrich; Borisov, Sergey M.; Klimant, Ingo; Larkum, Anthony W. D.

2012-01-01

128

Gracilis tendon transfer associated with distal alignment for patella alta with recurrent dislocations: an original surgical technique.  

PubMed

Many surgical techniques for the medial patellofemoral ligament have recently been suggested, all of which included problems identifying the femoral anchorage point and determining the proper extent of knee flexion for the transplant. P. Burdin proposed a different and original approach consisting in performing a gracilis muscle transfer to the medial edge of the patella, thus obtaining progressive tension of the transfer during knee flexion by means of the myotatic reflex. We report the results herein. We retrospectively assessed 17 knees treated for patellofemoral instability using this technique. Two cases presented subjective patellofemoral instability and 15 presented objective patellofemoral instability. The patients' mean age was 17.4 years (range, 8-47 years) during the first episode of dislocation. Two cases of instability were secondary to advanced neuromuscular disease. Two knees had already undergone two stabilization attempts. Fifteen knees presented trochlear dysplasia (four stage A, eight stage B, and three stage C). The mean age at surgery was 28.2 years (range, 16-47 years). In 15 cases, the gracilis transfer was associated with lowering the anterior tibial tuberosity (mean, 10mm). No patellar fracture occurred. A persistent sensory deficit of the anterior branch of the internal saphenous nerve was observed in 15 cases. One knee remained painful and retained subjective instability; total knee arthroplasty was performed 3 years after the intervention. The mean follow-up at revision was 5.5 years (range, 1.5-16.5 years). No recurrence of dislocation was reported. Eight cases retained subjective instability. The SF-36 and IKDC scores were good or excellent in 12 cases and the KOOS was good or excellent in 13 cases. Radiologically, patellar tilt persisted in six cases out of 14, translation persisted in two cases out of 14, and secondary patella baja was observed in one. Medial patellofemoral osteoarthritis was observed in five cases: one case IWANO stage I and four cases IWANO stage II. These satisfactory results seem stable over time and were acquired using a simple procedure with reduced morbidity, making it possible to avoid significant displacement of the anterior tibial tuberosity and stabilize the extensor apparatus. It can also be hoped that the onset of secondary patellofemoral osteoarthritis, undoubtedly inevitable, has been delayed. PMID:21530441

Marteau, E; Burdin, P; Brilhault, J-M

2011-06-01

129

Spatial diversity of rocky midlittoral macro-invertebrates associated with the endangered species Patella ferruginea (Mollusca: Gastropoda) of Tunisian coastline  

NASA Astrophysics Data System (ADS)

The present study focuses on horizontal spatial variability of benthic macrofauna associated with Patella ferruginea. Thirty-six samples collected at 12 transects belonging to 4 midlittoral sites along the rocky Tunisian coastline, were examined. A total of 44 species belonging to 5 taxa were found. Multivariate analysis applied on gathered data did not show a horizontal spatial variability at small scale (between transects), but at large scale, between sites as well as sectors. Thus, three groups of communities were identified (GI: Korbous and El Haouaria; GIIa: Zembra Island and GIIb: Kelibia). The distribution of species abundance within these groups revealed that crustaceans were the most abundant taxon, due to the overwhelming dominance of Chthamalus stellatus. This substratum appeared to create favourable micro-habitats for the installation of molluscs including gastropods. Regarding the low diversity index ( H') and evenness ( J), they seemed to reflect a disturbance and a demographic unbalance within these communities. The heterogeneity of substrate surface, created by C. stellatus specimens appeared to be caused by various complex interactions established between the key components of these communities in particular suspension feeders, predators, herbivorous molluscs and macroalgae. Thus, the dynamic status of each of these communities is the result of these complex interactions.

Tlig-Zouari, Sabiha; Rabaoui, Lotfi; Fguiri, Hosni; Diawara, Moctar; Ben Hassine, Oum Kalthoum

2010-04-01

130

Statistical assessment of a sampling pattern for evaluation of changes in mercury and zinc concentrations in Patella coerulea  

SciTech Connect

The validity and representativeness of sampling, whether in temporal or in geographic terms, are always a problematical aspect of the evaluation of metal pollution in coastal sea water. Numerous field studies have underscored the great variety in metal levels in a given site, even in the very short term. The choice of sedentary test species disposes of the variation factor associated with those that move from place to place. Because they are ubiquitous and easy to collect, mollusks have very often been used for this purpose. This is particularly true of the mussel and the oyster because they are eaten by man. The limpet (Patella) is a primary herbivore consumer and would seem an equally elective test organism. Its very localized feeding habits (grazing the algae colonizing the rocks where it lives) are less prone to sudden changes than those of the filtering mollusks. Indeed, it has already been employed in campaigns evaluating pollution by hydrocarbons and metals. To be able to compare several areas in this way, however, or follow their progress over the course of time, it is essential to work out a representative sampling plan. This paper reports an investigation of this aspect of the question with regard to two metals: mercury, which is toxic and plays no part in any natural metabolic process, and zinc, a cation required in weak concentrations by certain enzyme systems.

Puel, D.; Zsuerger, N.; Breittmayer, J.P.

1987-04-01

131

Arthroscopic Assessment and Treatment of Dancers' Knee Injuries.  

ERIC Educational Resources Information Center

Arthroscopic examination of 16 dancers with dance-related knee injuries which defied conservative treatment showed 15 meniscal tears and 4 cases of chondromalacia patellae. Partial arthroscopic meniscectomy was used to treat the tears. The results were excellent, with 13 of the 16 returning to preoperative levels of dance activity. (MT)

Silver, Daniel M.; Campbell, Pat

1985-01-01

132

Bioaccumulation of metals in the soft tissue of Patella aspera: Application of metal/shell weight indices  

NASA Astrophysics Data System (ADS)

Patella aspera limpets were taken from a marine clean site (MCS) and an estuarine contaminated site (ECS). The concentrations of Fe, Mn, Zn, Cu, Cd, Ni and Co were determined individually over the available size range. Since there were significant differences in the soft tissue weight between populations, but shell characteristics were similar (length and weight), metal/shell weight indices (MSI) were calculated in order to compare populations. For both populations iron, zinc and manganese/shell weight indices were consistently higher, in the order Fe ? Zn ? Mn than those of Cu, Ni, Co and Cd. The results exhibited a marked intra- and inter-population variability. The highest intra-variability was observed at ECS, particularly where a strong effect of shell weight upon the metal accumulation in the soft tissue was evident. Due to this effect, the comparison of populations was carried out between three selected shell weight ranges representative of light shells (0.45-1.95 g), intermediate shells (2.95-4.45 g) and heavy shells (5.45-7.33 g). The results indicate that, in general, MSI at ECS (a sewage contaminated site), except for Cd, was higher than at MCS possibly reflecting a higher environmental bioavailability of these metals. The resolution between populations was higher when the smallest range of limpets was considered and it decreased with the increase of shell weight. The highest discrimination amongst populations was found for zinc/shell weight index that showed much higher values than those of Mn, Cu, Cd, Ni and Co/shell weight indices, and spatial differentiation between populations persisted amongst the selected shell weight ranges.

Cravo, A.; Bebianno, M. J.

2005-11-01

133

Sclerochronology and geochemical variation in limpet shells (Patella vulgata): A new archive to reconstruct coastal sea surface temperature  

NASA Astrophysics Data System (ADS)

Climate archives contained in shells of the European limpet, Patella vulgata, accumulated in archaeological deposits can potentially provide much needed information about Holocene environmental change in midlatitude coastal areas. Before reconstructing climate information preserved in these zooarchaeological records, we studied the controls on oxygen and carbon isotope ratios (?18O and ?13C, respectively) in modern specimens. We tested the hypothesis that P. vulgata precipitates its shell in isotopic equilibrium with the ambient water by comparing ?18OSHELL with predicted values. Predicted ?18OSHELL was constructed using observed sea surface temperature (SST) records and the equilibrium fractionation equation for calcite and water. We assumed a constant ?18OWATER value of +0.10‰ (VSMOW) based on published regional measurements. Comparison of ?18OSHELL with predicted values revealed that ?18OSHELL values were higher than expected by +1.01 ± 0.21‰. Consequently, estimated SST calculated from ?18OSHELL was 4.2 ± 2.3°C lower than observed SST. However, because of the relatively uniform offset between observed and expected ?18O, an adjustment can be made to account for this predictable vital effect. Thus past climate can be reliably reconstructed using this temperature proxy once the offset is taken into account. ?13C values have a similar cyclicity to the ?18O variation and therefore vary seasonally. However, ?13C is slightly out of phase relative to ?18O. An overall negative shift in ?13CSHELL over the lifetime of the individual indicates a vital effect associated with ontogeny. Further study of environmental and ecological factors that influence shell ?13C is required to evaluate fully the potential of carbon isotope ratios as a useful environmental proxy.

Fenger, Tracy; Surge, Donna; SchöNe, Bernd; Milner, Nicky

2007-07-01

134

A Comparison of Patella Retention versus Resurfacing for Moderate or Severe Patellar Articular Defects in Total Knee Arthroplasty: Minimum 5-year Follow-up Results  

PubMed Central

Purpose The purpose of this study is to assess the clinical and radiological results of patients who underwent patellar retention or resurfacing for moderate or severe patellar articular defects during total knee arthroplasty and evaluate the clinical efficacy of patellar resurfacing according to the articular defect of the patella. Materials and Methods From May 2003 to March 2006, 252 patients (277 cases) underwent total knee arthroplasty by one surgeon. Intraoperatively, we divided these patients into a moderate articular defect group (50-75%: group I) and a severe articular defect group (75-100%: group II) and randomly performed patellar resurfacing. The average age was 67.2 years. There were 234 female and 17 male patients. The average follow-up period was 74.6 months. Clinical outcomes were analyzed using the Knee Society (KS) knee score. Functional score, Hospital for Special Surgery (HSS) score, Feller patellar score and range of motion (ROM). Radiological outcomes were analyzed using the congruence angle, Insall-Salvati ratio and patella tilt angle. Results The KS knee score and functional score at the last follow-up were 84.4/73.1 in the retention group and 85.2/71.8 in the resurfacing group (p=0.80, p=0.63) in group I. In group II, the values were 82.1/75.1 and 87.0/71.2, respectively (p=0.51, p=0.26). The HSS score and Feller patella score were 86.7/20.3 in the retention group and 84.3/21.7 in the resurfacing group (p=0.31, p=0.29) in group I. In group II, the values were 91.6/21.2 and 85.5/22.1, respectively (p=0.37/p=0.30). The knee ROM (p=0.36/p=0.41), congruence angle (p=0.22/p=0.16), Insall-Salvati ratio (p=0.16/p=0.21) and patella tilt angle (p=0.12/p=0.19) were not statistically different between the two groups. Conclusions In this study, we could not find any correlations between the degree of patellar articular defect and patellar resurfacing in terms of the clinical and radiological results. Therefore, patellar articular defects is thought to be less meaningful in determining patellar resurfacing. PMID:22570825

Seo, Seung Suk; Moon, Sang Won

2011-01-01

135

Paleoclimate of the Neoglacial and Roman Warm Period Reconstructed from Oxygen Isotope Ratios of Limpet Shells (Patella vulgata), Northwest Scotland  

NASA Astrophysics Data System (ADS)

Paleoclimate reconstructions from different regions have reported abrupt climate change around 2800-2700 cal yr B.P. The timing of this abrupt climate change is close to the boundary between the Neoglacial (3300-2500 cal yr B.P.) and Roman Warm Period (2500-1600 cal yr B.P.). However, temporal and spatial variability observed in this climate change event raises controversies about the forcing factors driving it and why it has regional variability. Scotland lies in the North Atlantic Ocean, which responds sensitively to climate change. Therefore, even in the case of subtle climate change, the climate variability of Scotland should be able to capture such change. In this study, we expect that paleoclimate reconstructions of the Neoglacial and Roman Warm Period in Scotland will help improve our knowledge of abrupt climate change at 2800-2700 cal yr B.P. Archaeological shell deposits provide a rich source of climate proxy data preserved as oxygen isotope ratios in shell carbonate. Croig Cave on the Isle of Mull, Scotland, contains a nearly continuous accumulation of shells ranging from 800 BC-500 AD and possibly older. This range represents a broad chronology of human use from the late Bronze to Iron Ages and spans the Neoglacial through Roman Warm Period climate episodes. Here, we present seasonal temperature variability of the two climate episodes based on oxygen isotope ratios of ten limpet shells (Patella vulgata) from Croig Cave. Based on AMS dating (2 sigma calibration), the oldest shell was from 3480-3330 cal yr B.P. and the youngest shell was from 2060-1870 cal yr B.P. Our results indicated that estimated temperatures from the Neoglacial limpets average 6.44±0.56°C for coldest winters and 15.06±0.67°C for warmest summers. For the Roman Warm Period limpets, the average is 5.68±0.36°C for coldest winters and 14.14±0.81°C for warmest summers. We compared our estimated temperatures to the present sea surface temperature (SST) from 1961 to 1990 near our study area, which averages 7.40±0.35°C for coldest month and 14.12±0.54°C for warmest month. Our reconstructed temperatures from the Neoglacial limpets showed slightly (0-1°C) colder winters, similar or warmer (1-1.8°C) summers compared to present SST record. One shell captured a year without a summer likely resulting from an eruption of the Katla volcanic system in Iceland. The reconstructed temperatures from the Roman Warm Period limpets showed colder winters (up to 2°C) and similar summers compared with present SST record. Our findings represent the first insights of SST variability at seasonal time scales for these two climate episodes in northwest Scotland.

Wang, T.; Surge, D. M.; Mithen, S.

2010-12-01

136

A Microdeletion of Chromosome 9q33.3 Encompasses the Entire LMX1B Gene in a Chinese Family with Nail Patella Syndrome.  

PubMed

Nail patella syndrome (NPS) is an autosomal dominant disorder characterized by nail malformations, patellar apoplasia, or patellar hypoplasia. Mutations within the LMX1B gene are found in 85% of families with NPS; thus, this gene has been characterized as the causative gene of NPS. In this study, we identified a heterozygous microdeletion of the entire LMX1B gene using multiplex ligation-dependent probe amplification (MLPA) in a Chinese family with NPS. The determination of the deletion breakpoints by Illumina genome-wide DNA analysis beadchip showed that the deletion was located in chromosome 9q33.3 and spanned about 0.66 Mb in size. This heterozygous deletion provides strong evidence for haploinsufficiency as the pathogenic mechanism of NPS. PMID:25380522

Jiang, Shujuan; Zhang, Jiubin; Huang, Dan; Zhang, Yuanyuan; Liu, Xiaoliang; Wang, Yinzhao; He, Rong; Zhao, Yanyan

2014-01-01

137

Intraarticular reaction associated with the use of freeze-dried, ethylene oxide-sterilized bone-patella tendon-bone allografts in the reconstruction of the anterior cruciate ligament  

Microsoft Academic Search

One hundred nine patients over a 3 year period under went reconstruction for chronic ACL ruptures using a freeze-dried, ethylene oxide-sterilized bone-patella ten don-bone allograft. Seven patients (6.4%) developed a characteristic persistent intraarticular reaction. This re action was characterized by persistent synovial effusion with collagenous particulates and cellular inflammatory response. Synovial biopsies in all cases showed a similar chronic inflammatory

Douglas W. Jackson; Gary E. Windler; Timothy M. Simon

1990-01-01

138

A simple technique for reconstruction of medial patellofemoral ligament with bone-fascia tunnel fixation at the medial margin of the patella: a 6-year-minimum follow-up study  

PubMed Central

Background Medial patellofemoral ligament (MPFL) reconstruction has become an accepted technique to treat patellofemoral instability, and numerous surgical techniques have been described to reconstruct the MPFL. We describe a MPFL reconstruction procedure where bone-fascia tunnel fixation occurs at the medial margin of the patella for recurrent patellar dislocation. Objective MPFL reconstruction is the preferred operative treatment for recurrent patellar dislocation. The purpose of this study was to report a simple technique for reconstruction of medial patellofemoral ligament with bone-fascia tunnel fixation at the medial margin of the patella for recurrent patellar dislocation and to evaluate the results at 6-year-minimum follow-up. Methods The study included 65 patients (28 males, 37 females; mean age, 29.4?±?5.6 years) who underwent MPFL reconstruction using the bone-fascia tunnel fixation at the medial margin of the patella technique and who were followed for a mean duration of 78.5?±?3.8 months. Objective assessment, Kujala scale, Lysholm score, and Tegner activity score were obtained preoperatively and at the time of final follow-up. Results There were no patellar complications, including redislocation, in the present study. The congruence angle had significant improvement from 19.2°?±?6.3° before surgery to ?6.03°?±?0.50° at the last follow-up. The lateral patellar angle had significant improvement from ?6.9°?±?3.5° before surgery to 5.1°?±?2.4° at the last follow-up. The patellar tilt angle had significant improvement from 24.5°?±?5.2° before surgery to 12.30°?±?1.90° at the last follow-up. The Kujala score was significantly increased from 52.9?±?3.2 points preoperatively to 90.1?±?5.8 points postoperatively (P?patella fracture, anatomically to restore physiological kinematics and stability, and economically to reduce costs with bone-fascia tunnel fixation at the medial margin of the patella. PMID:25123919

2014-01-01

139

MRI of Cartilage: Pathological Findings  

Microsoft Academic Search

\\u000a The most important clinical indications for magnetic resonance imaging (MRI) are assessment of cartilage in osteoarthritis\\u000a (OA), chronic or acute osteochondral injury including sports injuries, osteochondritis dissecans, chondromalacia patellae,\\u000a and inflammatory arthropathies (in particular before invasive therapy). In addition dedicated cartilage imaging is required\\u000a after invasive cartilage repair procedures or conservative therapies, including pharmacological therapies, to monitor treatment\\u000a effect. MR

Thomas M. Link

140

c.194 A>C (Q65P) mutation in the LMX1B gene in patients with nail-patella syndrome associated with glaucoma  

PubMed Central

Purpose To report the clinical, ophthalmic, extraophthalmic, and genetic characteristics of nail-patella syndrome (NPS) in a Chilean family and to investigate the expressivity of open angle glaucoma (OAG) and ocular hypertension (OHT) in the family members. Methods Five family members affected with NPS and two unaffected members underwent a complete ophthalmologic examination, including computerized visual field, optical coherence tomography (OCT) of the optic disc and ultrasound pachymetry. Renal function was assessed by urinalysis and blood tests. Orthopedic evaluations were also performed, including radiological studies of the wrist, elbow and hip joints. Genomic DNA was extracted from peripheral leukocytes of the five affected and two unaffected family members. Exons 2–6 of the LIM homeobox transcription factor 1-beta (LMX1B) gene were screened for mutations by DNA sequencing of the proband. We also screened for mutations in exon 2 by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) of the other participants and 91 blood donors. Results Five living family members from three generations were positively diagnosed with NPS, three of them with varying degrees of OAG and one with OHT. Retinal nerve fiber layer (RNFL) thickness measured by spectral domain OCT was below normal values in three individuals. All subjects evaluated had normal nephrologic function. Orthopedic, clinical, and radiological alterations were compatible with NPS. Screening for mutations in exons 2- 6 of LMX1B showed a heterozygous missense mutation c.194 A>C changing glutamine to proline within exon 2 in codon 65 (Q65P) of the coding sequence. This mutation was present in all NPS subjects and absent in the unaffected family members and in 91 Chilean blood donors. Conclusions This is the first report of c.194 A>C mutation in LMX1B in a Chilean family with NPS and the second worldwide. The phenotype associated with this mutation is variable within the family, although we noted a close connection between the presence of the c.194 A>C mutation and the presence of OHT or OAG and probably also with an early onset of OHT in patients with NPS. All subjects older than 21 years had either OHT or OAG. We also suggest that the LMX1B mutation may be related to affective disorders. PMID:21850167

Romero, Pablo; Sanhueza, Felipe; Lopez, Pamela; Reyes, Loreto

2011-01-01

141

COL5A1: Genetic mapping and exclusion as candidate gene in families with nail-patella syndrome, tuberous sclerosis 1, hereditary hemorrhagic telangiectasia, and Ehlers-Danlos syndrome type II  

SciTech Connect

COL5A1, the gene for the {alpha}1 chain of type V collagen, has been considered a candidate gene for certain diseases based on chromosomal location and/or disease phenotype. We have employed 3{prime}-untranslated region RFLPs to exclude COL5A1 as a candidate gene in families with tuberous sclerosis 1, Ehlers-Danlos syndrome type H, and nail-patella syndrome. In addition, we describe a polymorphic simple sequence repeat (SSR) within a COL5A1 intron. This SSR is used to exclude COL5A1 as a candidate gene in hereditary hemorrhagic telangiectasia (Osler-Rendu-Weber disease) and to add COL5A1 to the existing map of {open_quotes}index{close_quotes} markers of chromosome 9 by evaluation of the COL5A1 locus on the CEPH 40-family reference pedigree set. This genetic mapping places COL5A1 between markers D9S66 and D9S67. 14 refs., 1 fig., 2 tabs.

Greenspan, D.S. [Univ. of Wisconsin Medical School, Madison, WI (United States)] [Univ. of Wisconsin Medical School, Madison, WI (United States); Northrup, H.; Au, K.S. [Univ. of Texas Medical School, Houston, TX (United States)] [and others] [Univ. of Texas Medical School, Houston, TX (United States); and others

1995-02-10

142

Imaging of the patellofemoral joint.  

PubMed

The patellofemoral (PF) joint is a complex articulation, with interplay between the osseous and soft tissue structures to maintain the balance between knee mobility and stability. Disorders of the PF joint can be a source of anterior knee pain (AKP). In this article, radiographic and magnetic resonance imaging of the PF joint are reviewed, including normal anatomy, imaging techniques, and imaging-based measurements. Common imaging findings associated with AKP are reviewed, including symptomatic normal variants, tendinopathy, apophysitis, osteoarthritis, chondromalacia patella, trochlear dysplasia, excessive lateralization of tibial tuberosity, patellar maltracking, patellar dislocation and fractures, anterior bursitis, Morel-Lavallée effusions, and fat pad edema. PMID:24993408

Thomas, Stephen; Rupiper, David; Stacy, G Scott

2014-07-01

143

The operative management of patella malalignment.  

PubMed

Management of patellofemoral joint pathology is challenging as a result of the unique and complex organization of static forces and dynamic factors contributing to its functional capacity. Anterior knee pain is a common musculoskeletal complaint seen daily in the practices of primary care physicians, rheumatologists, and orthopedic surgeons. The key to successful treatment lies not only in the correct diagnosis of a chondral defect, but more importantly, in the accurate identification of associated pathomechanical factors. Appreciating the pathoanatomic basis of the disease and addressing imbalances and anatomical abnormalities should guide treatment.Despite the complexity of the interplay of various components it is essential to attempt to describe patellar malalignement as a clinical entity in order to proceed with appropriate surgical management and successful outcomes. The goals of patellofemoral re- alignment surgery should be to create both a stable environment for optimal extensor mechanism performance and an appropriate load transmission for optimal cartilage wear and joint loading. In the context of this article we will review the operative management of patellofemoral malalignment; the indications for surgery, the different techniques available and the evidence regarding their effectiveness.A large number of procedures have been employed and they have all undergone various modifications over the course of the years. The majority of publications are retrospective series in poorly defined population groups. There are significant methodological inconsistencies and as a result there is lack of strong evidence base for the majority of these procedures. PMID:22927893

Iliadis, Alexios Dimitrios; Jaiswal, Parag Kumar; Khan, Wasim; Johnstone, David

2012-01-01

144

The Operative Management of Patella Malalignment  

PubMed Central

Management of patellofemoral joint pathology is challenging as a result of the unique and complex organization of static forces and dynamic factors contributing to its functional capacity. Anterior knee pain is a common musculoskeletal complaint seen daily in the practices of primary care physicians, rheumatologists, and orthopedic surgeons. The key to successful treatment lies not only in the correct diagnosis of a chondral defect, but more importantly, in the accurate identification of associated pathomechanical factors. Appreciating the pathoanatomic basis of the disease and addressing imbalances and anatomical abnormalities should guide treatment. Despite the complexity of the interplay of various components it is essential to attempt to describe patellar malalignement as a clinical entity in order to proceed with appropriate surgical management and successful outcomes. The goals of patellofemoral re- alignment surgery should be to create both a stable environment for optimal extensor mechanism performance and an appropriate load transmission for optimal cartilage wear and joint loading. In the context of this article we will review the operative management of patellofemoral malalignment; the indications for surgery, the different techniques available and the evidence regarding their effectiveness. A large number of procedures have been employed and they have all undergone various modifications over the course of the years. The majority of publications are retrospective series in poorly defined population groups. There are significant methodological inconsistencies and as a result there is lack of strong evidence base for the majority of these procedures. PMID:22927893

Iliadis, Alexios Dimitrios; Jaiswal, Parag Kumar; Khan, Wasim; Johnstone, David

2012-01-01

145

Acute Dislocation of the PatellaA Correlative Pathoanatomic Study  

Microsoft Academic Search

The objective of our study was to elucidate the char acteristic pathoanatomy associated with patellar dislo cation and report the preliminary results of early surgi cal repair. Twenty-three patients with documented patellar dislocation had standard radiographs and a magnetic resonance imaging scan. Intraarticular le sions were evaluated and treated arthroscopically fol lowed by an open exploration of the medial aspect

Peter I. Sallay; Jeffery Poggi; Kevin P. Speer; William E. Garrett

1996-01-01

146

Patella resurfacing in total knee replacement: functional evaluation and complications  

Microsoft Academic Search

Three different knee replacements, with three trochlear designs, were prospectively evaluated clinically and radiographically for patellar function and presence of patellar complications. They included the Insall-Burstein (IB) I and the IB-II (posterior cruciate ligament substituting) and the Meniscal Bearing Knee (MBK; posterior cruciate ligament recession). The trochlea of the IB-I was short and shallow with an anterior sharp edge of

P. Aglietti; A. Baldini; R. Buzzi; P. F. Indelli

2001-01-01

147

The biomechanics of the human patella during passive knee flexion  

Microsoft Academic Search

The fundamental objectives of patello-femoral joint biomechanics include the determination of its kinematics and of its dynamics, as a function of given control parameters like knee flexion or applied muscle forces. On the one hand, patellar tracking provides quantitative information about the joint's stability under given loading conditions, whereas patellar force analyses can typically indicate pathological stress distributions associated for

J. Heegaard; P. F. Leyvraz; A. Curnier; L. Rakotomanana; R. Huiskes

1995-01-01

148

Presentation and outcome of primary tumors of the patella.  

PubMed

Demographics, pathology, and outcomes of 7 patellar tumors, including 2 giant cell tumors, 2 chondroblastomas, 1 osteoid osteoma, 1 osteitis fibrosa cystica, and 1 case of myelomatous infiltration, are described. Five male and 2 female patients with a mean age of 42.5 years were followed for an average of 3.5 years. Anterior knee pain was the main presenting symptom. Two patients presented with pathologic fracture. One patient with chondroblastoma underwent curettage only; the second patient underwent curettage and bone grafting. Both patients with giant cell tumors underwent total patellectomy. Patients with osteoblastoma and osteitis fibrosa cystica underwent excision of the lesion. The patient with myeloma underwent radiotherapy. Patellar tumors represent special management problems because of their subcutaneous location, relationship to the extensor mechanism, and difficulties in interpretation of radiographs. A satisfactory outcome can be expected in the majority because of the predominantly benign nature of the lesions and straightforward operative intervention after diagnosis. PMID:18686483

Bhagat, Shaishav; Sharma, Himanshu; Bansal, Mohit; Reid, R

2008-07-01

149

The influence of patellofemoral joint loading on patella strain and patella water content in females with patellofemoral pain.  

E-print Network

??Recent research has suggested that patellofemoral pain (PFP) may be the result of elevated loading of highly-innervated subchondral bone during weight-bearing activities. Furthermore, excessive bone… (more)

Ho, Kai-Yu

2012-01-01

150

Correlation between trochlear dysplasia and anterior cruciate ligament injury.  

PubMed

PURPOSE. To evaluate the correlation between trochlear dysplasia and anterior cruciate ligament (ACL) injury METHODS. Magnetic resonance images (MRIs) of 95 knees in 54 males and 36 females aged 4 to 74 (mean, 28) years who had anterior knee pain and suspected ligamentous injury were reviewed. The MRIs were independently reviewed by 2 musculoskeletal radiologists on 2 occasions. According to the Dejour classification, trochlear dysplasia was classified into types A, B, C, and D. Intra-articular injuries/ disorders of the patients included patellofemoral osteoarthritis, chondromalacia patella, meniscal tears, and ligamentous injuries. Intra- and inter-observer variability was calculated. RESULTS. 58 of the knees had trochlear dysplasia, 38 of which were Dejour type A. The intra- and inter-observer variability was good to excellent (Kappa=0.76-1). ACL tear was the most common injury (n=13). No ACL injury occurred in patients without trochlear dysplasia. The odds of having sustained an ACL injury were 8.8 fold greater in Dejour type-A knees than in non-type-A knees (p=0.023). CONCLUSION. Dejour type-A trochlear dysplasia was associated with ACL injuries. PMID:24014781

Botchu, Rajesh; Obaid, Haron; Rennie, W J

2013-08-01

151

Clinical and radiological outcome of medial patellofemoral ligament reconstruction with a semitendinosus autograft for patella instability  

Microsoft Academic Search

Background: Recurrent patellar instability is a common problem after dislocation. The medial patellofemoral ligament (MPFL) contributes 40–80% of the total medial restraining forces. This study assessed the clinical and radiological outcome after a follow-up of 4 years after linear MPFL reconstruction using an ipsilateral Semitendinosus tendon autograft. Study design and methods: 15 knees in 12 patients were examined with a mean

PB Schöttle; SF Fucentese; J Romero

2005-01-01

152

The determination of ultrasound velocity in the os calcis, thumb and patella during childhood  

Microsoft Academic Search

Maximising the accumulation of bone tissue during growth and puberty is one of the most important aims in the prevention of osteoporosis. For prevention studies in children it is necessary to develop methods for skeletal status without radiation. Ultrasonic velocity (speed of sound=SOS) has been proposed as an alternative method. Using a new ultrasonic system (Osteoson K4, Minhorst, Germany), we

Eckhard Schönau; Anja Radermacher; Ulrike Wentzlik; Klaus Klein; Dietrich Michalk

1994-01-01

153

Universite Paris-Sud Ecole Doctorale 534 Mipege  

E-print Network

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 Patella vulgata . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 2.2 Foli´e crois´e : Patella vulgata . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 2

Paris-Sud XI, Université de

154

Jumper's knee. Review of the literature.  

PubMed

Jumper's knee is an overuse disease. The initial subjective complaints are well-localized pain, usually occurring after physical activities and often at the lower pole of the patella. The diagnosis of jumper's knee is usually easily established after acquiring a detailed history and a carefully performed physical examination, but the lesion can be mistaken for other disorders or injuries, such as bursitis, meniscal injuries or chondromalacia (1) or other causes of the patellofemoral pain syndrome. Today ultrasonography is the method of choice for the evaluation of jumper's knee as it is both time and cost saving, non-invasive, repeatable, accurate and allows a dynamic image of the tendon, guided injections and control of treatment. Conservative therapy is the treatment of choice in the early stages and includes adequate warm-up, stretching of the quadriceps muscle and physical activity with respect to the pain, and ice pack application after activity. When the pain disappears, the training intensity can be increased. NSAID (Non-Steroidal Anti-Inflammatory Drugs) and local peritendinous injections with long-acting steroids can be a helpful and safe adjuvant to the conservative treatment and should be tried before surgery. Surgical treatment is indicated only if a prolonged and well-supervised conservative treatment program fails in chronic jumper's knee (including local injection with steroid) or in acute total rupture. Review papers concerning jumper's knee are already published (2-5), but in this review the importance of ultrasonography to make the diagnosis, to plan therapy and control the treatment and the safety of peritendinous injection with steroid is pointed out. The scientific documentation for the recommanded treatment (conservative, steroid injection and operation) is, however, insufficient. Many more controlled studies are needed. Ultrasonography and placebo-controlled, double-blinded, cross-over studies for treatment with local injection of steroid are ongoing (6, 7). PMID:10220839

Fredberg, U; Bolvig, L

1999-04-01

155

AT1 receptor characteristics of angiotensin analogue binding in human synovium.  

PubMed Central

1. Angiotensin II (AII) reduces blood flow, modulates vascular remodelling and is a growth factor. Human inflammatory arthritides are characterized by synovial hypoperfusion, hypoxia and proliferation. We aimed to localize and characterize receptors for AII in human synovium. 2. We used quantitative in vitro receptor autoradiography with [125I]-(Sar1, Ile8)AII and [125I]-AII on human synovium from patients with chondromalacia patellae, osteoarthritis and rheumatoid arthritis. 3. [125I]-(Sar1, Ile8)AII and [125I]-AII bound to similar sites on synovial blood vessels, lining cells and stroma. Binding to microvessels (< 100 microns diameter) was more dense than to arteriolar media, and vascular binding was more dense than that to lining cells and stroma. 4. Microvessels and arterioles which displayed angiotensin converting enzyme-like immunoreactivity also displayed specific binding of [125I]-(Sar1, Ile8)AII. 5. Specific binding of [125I]-(Sar1, Ile8)AII to each structure was completely inhibited by 10 microM dithiothreitol and was inhibited by unlabelled ligands with the rank order of potency (Sar1, Ile8)AII > AII > losartan = SKF108566 > PD123319 indicating an AT1 subclass of angiotensin receptor. 6. GTP gamma S (1 microM) abolished specific binding of [125I]-AII and abolished the high affinity component of the binding inhibition curve for AII against [125I]-(Sar1, Ile8)AII, indicating G protein coupling. 7. The distribution of [125I]-(Sar1, Ile8)AII binding sites was similar in all disease groups and no significant differences in binding densities, affinities or specificities were observed between disease groups. 8. Locally generated AII may act on synovial AT1 receptors to modulate synovial perfusion and growth. Specific AT1 receptor antagonists should help elucidate the role of angiotensins in human arthritis. Images Figure 1 Figure 2 PMID:8075862

Walsh, D. A.; Suzuki, T.; Knock, G. A.; Blake, D. R.; Polak, J. M.; Wharton, J.

1994-01-01

156

The 3-in-1 Procedure for Recurrent Dislocation of the Patella in Skeletally Immature Children and Adolescents  

Microsoft Academic Search

Background: Recurrent patellar dislocations are common injuries in children and adolescents. The subjective and functional results of soft tissue surgical management in a population that was skeletally immature at the time of surgery have not been reported.Hypothesis The 3-in-1 procedure is an effective treatment for recurrent patellar dislocation in skeletally immature patients.Study Design: Case series; Level of evidence, 4.Methods: Twenty-five

Francesco Oliva; Mario Ronga; Umile Giuseppe Longo; Vittorino Testa; Giovanni Capasso; Nicola Maffulli

2009-01-01

157

Comparison of the Insall–Salvati ratio of the patella in patients with and without an ACL tear  

Microsoft Academic Search

The object of this prospective study is to compare the Insall–Salvati ratio between the patients who have an anterior cruciate ligament (ACL) tear and receive arthroscopic–assistant ACL reconstruction and the patients who have no ACL tear but do have an internal disorder of the knee and receive arthroscopic surgery. We prospectively and consecutively collected into two groups a total of

Chien-Fu Jeff Lin; Jiunn-Jer Wu; Teng-Shung Chen; Tung-Fu Huang

2005-01-01

158

Patellamide A and C biosynthesis by a microcin-like pathway in Prochloron didemni, the cyanobacterial symbiont of Lissoclinum patella  

PubMed Central

Prochloron spp. are obligate cyanobacterial symbionts of many didemnid family ascidians. It has been proposed that the cyclic peptides of the patellamide class found in didemnid extracts are synthesized by Prochloron spp., but studies in which host and symbiont cells are separated and chemically analyzed to identify the biosynthetic source have yielded inconclusive results. As part of the Prochloron didemni sequencing project, we identified patellamide biosynthetic genes and confirmed their function by heterologous expression of the whole pathway in Escherichia coli. The primary sequence of patellamides A and C is encoded on a single ORF that resembles a precursor peptide. We propose that this prepatellamide is heterocyclized to form thiazole and oxazoline rings, and the peptide is cleaved to yield the two cyclic patellamides, A and C. This work represents the full sequencing and functional expression of a marine natural-product pathway from an obligate symbiont. In addition, a related cluster was identified in Trichodesmium erythraeum IMS101, an important bloom-forming cyanobacterium. PMID:15883371

Schmidt, Eric W.; Nelson, James T.; Rasko, David A.; Sudek, Sebastian; Eisen, Jonathan A.; Haygood, Margo G.; Ravel, Jacques

2005-01-01

159

Rate of blunt impact loading affects changes in retropatellar cartilage and underlying bone in the rabbit patella.  

PubMed

Our laboratory has developed a small animal model using Giant Flemish rabbits to examine chronic degradative changes in joint tissues following a blunt impact. Historically, we observe surface fissuring and decreases in the elastic modulus of retropatellar cartilage along with thickening of the underlying subchondral bone. Previous studies resulted in load insults that peaked in approximately 5ms, while loads that occur during automotive accidents or heavy exercise can produce longer rise times. The objective of the current study was to examine the influence of blunt impact loading rate using our established model. We hypothesized that the extent of fissuring and softening of retropatellar cartilage following impact would not be significantly different for a high (5ms to peak) versus low (50ms to peak) rate of loading experiment. Eight animals were impacted with a high rate of loading blunt impact, while ten animals were subjected to the same impact load at a low rate of loading. An additional eight animals served as a control population. All animals were sacrificed 12 months post-impact. The study yielded unexpected results for the first hypothesis. The high rate of loading experiments generated more surface fissuring of the retropatellar cartilage than the low rate of loading experiments. However, the degree of softening was similar for the two rates, which supported the second hypothesis. Furthermore, the study documented more thickening of bone underlying retropatellar cartilage following the high versus the low rate of loading experiments. The current study suggested that chronic injury mechanisms may be highly dependent on the rate of impact loading. These data could become extremely relevant in the development of high-velocity "safety" devices, such as knee air bags, that are needed to help position an unbelted occupant in an automobile crash. PMID:12020994

Ewers, B J; Jayaraman, V M; Banglmaier, R F; Haut, Roger C

2002-06-01

160

Fincke, O. M., L. Higgins and E. Rojas. 1990. Parasitism of Nephila clavipes (Araneae, Tetragnathidae) by an ichneumonid (Hymenoptera, Polyspinctini) in Panama. J. Arachnol.,  

E-print Network

on BCI and the size of the spider was measured by the tibia-patella length. The cephalothorax-abdomen length of female spiders was highly correlated with tibia- patella length (r = 0.96, N = 21 females, P patella

Fincke, Ola M.

161

Low-grade fibromyxoid sarcoma around the knee involving the proximal end of the tibia and patella: A rare case report  

PubMed Central

Low-grade fibromyxoid sarcoma (LGFMS) is a distinctive variant of fibrosarcoma. LGFMS is a rare soft tissue tumor that tends to develop in the deep soft tissue of young adults and has the potential for local recurrence or distant metastasis. The current case report presents a 22-year-old male complaining of a slow growing painless mass in the right knee over a period of 10 years. Following complete evaluation by radiological and histopathological examination, a diagnosis of LGFMS was confirmed and a wide excision was performed. Currently, the patient has been under follow-up for the last five years without any evidence of metastasis. The present case report provides further information concerning the diagnosis, imaging and management of LGFMS. PMID:24944715

BAJPAI, JEETENDRA; SHUKLA, SAURAV; JAH, MOAZZAM; SINGH, ALOK KUMAR; GOEL, MOHIT; MOURYA, AMIT; SACHDEVA, NIKHIL

2014-01-01

162

Periprosthetic fracture of the tibia associated with osteolysis caused by failure of rotating patella in low-contact–stress total knee arthroplasty  

Microsoft Academic Search

Periprosthetic fracture of the tibial plateau associated with osteolysis resulting from mechanical failure of the rotating patellar component after total knee arthroplasty with the New Jersey Low-Contact-Stress (LCS) knee (DePuy, Warsaw, IN) has not been reported previously. A 67-year-old woman with rheumatoid arthritis of the left knee had a LCS prosthesis implanted without cement, using a rotating patellar component. Seven

Tetsu Watanabe; Tetsuya Tomita; Masakazu Fujii; Motoharu Kaneko; Hironobu Sakaura; Eiji Takeuchi; Kazuomi Sugamoto; Hideki Yoshikawa

2002-01-01

163

Periprosthetic fracture of the tibia associated with osteolysis caused by failure of rotating patella in low-contact-stress total knee arthroplasty.  

PubMed

Periprosthetic fracture of the tibial plateau associated with osteolysis resulting from mechanical failure of the rotating patellar component after total knee arthroplasty with the New Jersey Low-Contact-Stress (LCS) knee (DePuy, Warsaw, IN) has not been reported previously. A 67-year-old woman with rheumatoid arthritis of the left knee had a LCS prosthesis implanted without cement, using a rotating patellar component. Seven years later, a fracture of the lateral tibial plateau occurred owing to an osteolytic defect with no traumatic accident. The rotating patellar bearing over-rotated and locked; consequently, wear occurred between the patellar metal tray and the femoral component. Immunohistochemistry revealed CD68-positive macrophages in the osteolytic region and phagocytosis of metal particles. The osteolytic region was filled with autogenous bone, and all components were exchanged and cemented. The patient's condition became satisfactory with relief of pain. PMID:12478519

Watanabe, Tetsu; Tomita, Tetsuya; Fujii, Masakazu; Kaneko, Motoharu; Sakaura, Hironobu; Takeuchi, Eiji; Sugamoto, Kazuomi; Yoshikawa, Hideki

2002-12-01

164

Posterior Cruciate Ligament Reconstruction Using Single-Bundle Patella Tendon Graft With Tibial Inlay Fixation2- to 10Year Follow-up  

Microsoft Academic Search

Purpose: Reconstruction of the posterior cruciate ligament (PCL) using the tibial inlay fixation has been reported as an alternative to the transtibial tunnel technique. Previous failures in PCL reconstruction and early reports raising potential biomechanical and clinical advantages have spurred interest in this technique. The purpose of this study was to evaluate the minimum 2-year results of PCL reconstruction using

Daniel E. Cooper; Donna Stewart

2004-01-01

165

Forces Acting on the Patella during Maximal Voluntary Contraction of the Quadriceps femoris Muscle at Different Knee Flexion\\/Extension Angles  

Microsoft Academic Search

From knee extension moments measured with a dynamometer, the quadriceps muscle force, the patellar ligament force and the reaction force in the patellofemoral joint at various knee angles (0–90°) were estimated. The information needed to calculate the combined effect of both patellofemoral and tibiofemoral joint on the mechanical advantage of the muscle was obtained from lateral-view radiographs of autopsy knees.The

W. A. Weijs; E. K. Kouwenhoven; J. Verburg

1987-01-01

166

MRI evaluation of anterior knee pain: predicting response to nonoperative treatment  

Microsoft Academic Search

Objective  Tibial tubercle lateral deviation and patellofemoral chondromalacia are associated with anterior knee pain (AKP). We hypothesized\\u000a that increased tibial tubercle lateral deviation and patellofemoral chondromalacia on magnetic resonance imaging correlates\\u000a with the presence of AKP and with failure of nonoperative management.\\u000a \\u000a \\u000a \\u000a Materials and methods  In this retrospective comparative study, a blinded musculoskeletal radiologist measured tibial tubercle lateral deviation\\u000a relative to the

Jocelyn R. Wittstein; Seth D. O’Brien; Emily N. Vinson; William E. Garrett

2009-01-01

167

Jumper's Knee (Patellar Tendonitis) (For Parents)  

MedlinePLUS

... tissue that joins the patella (kneecap) to the tibia (shin bone). Jumper's knee is an overuse injury ( ... function properly: Bones like the femur (thighbone), the tibia (shinbone), and the patella (kneecap) give the knee ...

168

Marine Biodiversity and Climate To use a combination of archival and contemporary data to  

E-print Network

, Semibalanus balanoides, Fucus serratus, Osilinus lineatus and Patella vulgata. ·Current scenarios suggest. 182. Right:Patella aspera Left: Current distribution Right:Semib- alanus balanoides Left: Current

Power, Anne Marie

169

MFR PAPER 1282 Relationship Between Size Composition and Ex-Vessel Value of  

E-print Network

. PATELLA ABSTRACT- This paper describes the effect on ex-vessel value of size com- position of reported Charles W. Caillouet and Frank J. Patella are with the Galveston Laboratory, Southeast Fisheries Center

170

MEXUS-Gulf Shrimp Research, 1978-84 EDWARD F. KLIMA, REFUGIO GMO. CASTRO MELENDEZ, NEAL BAXTER,  

E-print Network

, FRANK J. PATELLA, TERRY J. CODY, and LOREnA F. SULLIVAN Introduction Mexico and the United States share. Klima, K. Neal Baxter, Frank 1. Patella, and Loretta F. Sullivan are with the Galveston Laboratory

171

CHARLES W. CAILLOUET, DENNIS B. KOI, and WILLIAM B. JACKSON Relationship Between Ex-vessel Value and  

E-print Network

, NOAA. Gal veston, Tex similar to those used by Caillouet and Patella (1978) and Caillouet et al. (1979 Caillouet and Patella (1978) and Caillouet et al. (1979). 2Not determined. Calculations were made only

172

The Influence of Running on Patellar Water Content and Bone Marrow Edema in Females with and without Patellofemoral , H. H. Hu2  

E-print Network

marrow region; (b) local BME. Fig. 2. Both PFP subjects showed local BME on the lateral facet of patella local BME on the lateral facet of patella (Fig. 2). After running, PFP subjects reported an average

Southern California, University of

173

Kneecap dislocation - aftercare  

MedlinePLUS

Your kneecap (patella) sits over the front of your knee joint. As you bend or straighten your knee, the underside of ... 2010;29:81-106. Steiner T, Parker RD. Patella: subluxation and dislocation. 2. Patellofemoral instability: recurrent dislocation ...

174

Neuron, Vol. 18, 959968, June, 1997, Copyright 1997 by Cell Press The Efficiency of Sensory Information Coding  

E-print Network

the neuron was patella. It has seven to eight cuticular slits, ranging fromallowed to generate a receptor of the cost of encoding on the anterior-ventral surface on the patella, suggestanalog signals into action

Juusola, Mikko

175

In-vivo assessment of patellofemoral joint stress using a finite-element analysis , S. Farrokhi2  

E-print Network

components were the femur, the tibia, the patella, the patellar cartilage, and the femoral cartilage to fix them in space, while applying the quadriceps forces to the patella, which has 6 degrees of freedom

Valero-Cuevas, Francisco

176

438 IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 18, NO. 1, JANUARY 2003 High-Frequency Digital PWM Controller IC for  

E-print Network

Controller IC for DC­DC Converters Benjamin J. Patella, Aleksandar Prodic´, Student Member, IEEE, Art Zirger Electronics Center. Recommended by Associate Editor S. B. Leeb. B. J. Patella is with the Hewlett

Prodiæ, Aleksandar

177

In the simulation of human and animal bodies, complicated mechanical contact between nonlinearly  

E-print Network

(initial) position (right). Note that the patella slides over the head of the femur. Fig. 3. Skin surface natural looking sliding contact between skin areas, skin and bones/muscles, patella and femur. The complex

State, Andrei

178

Journal of Biomechanics 35 (2002) 10291037 ASB pre-doctoral young investigator award 2001  

E-print Network

the patella and reattached to one of the knee flexor tendons. The outcomes of this procedure are variable surgery, the distal tendon of the rectus femoris is detached from the patella and reattached to one

Delp, Scott

179

Multi-Angle Deformation Analysis of Hoffa's Fat Pad Kevin Stevensona, Mark Schweitzerb, Ghassan Hamarneha  

E-print Network

, inferior to the patella and dorsal to the patellar tendon. The fat pad is covered by synovial membrane of the infrapatellar (Hoffa) fat pad in relation to the patella, femur and tibia. Corresponding author: hamarneh

Hamarneh, Ghassan

180

I.G.I. Onlus -Bari ISTITUTO GRUPPOANALITICO ITALIANO  

E-print Network

alla Facolt� di Medicina e Chirurgia dell'Universit� degli Studi `Aldo Moro' di Bari Alberto Patella istituzionali. ANALISTA SUPERVISORE Prof. Alberto Patella h. 13.30: REGISTRAZIONE h. 14.15 - 15.30: PRIMA

Lanubile, Filippo

181

TRENDS TOWARD DECREASING SIZE OF BROWN SHRIMP, PENAEUS AZTECUS, AND WHITE SHRIMP, PENAEUS SETIFERUS, IN  

E-print Network

, IN REPORTED ANNUAL CATCHES FROM TEXAS AND LOUISIANA1 CHARLES W. CAILLOUET, FRANK J. PATELLA, AND WILUAM B and larval phases offshore (Cail- louet and Patella 1978), thus recruitment to the fishery begins

182

Universittsmedizin Gttingen Publikationen und Hochschulschriften 2010  

E-print Network

dislocations considering trochlear dysplasia, patella alta, and tibial tuberosity-trochlear groove distance and tibial tubercle-trochlear groove distance is more pronounced in women who dislocate the patella. AM J

Gollisch, Tim

183

Routine patellar resurfacing using an inset patellar technique  

Microsoft Academic Search

The management of the patella in total knee arthroplasty still causes controversy. Whether or not to resurface the patella\\u000a in primary total knee arthroplasty remains unclear. In this study we examined 220 consecutive total knee replacements, by\\u000a a single surgeon, where the patella was routinely resurfaced using the inset technique. All patellae were suitable for resurfacing.\\u000a Patellar thickness was not

Conor Hurson; Abdalla Kashir; Robert Flavin; Ian Kelly

2010-01-01

184

In vivo and Noninvasive Load Sharing among the Vasti in Patellar Malalignment  

E-print Network

on the patella by the medial and lateral vasti and passive structures. Imbalanced torques gen- erated with patellar malalignment and maltracking in the femoral groove (26,15,29). The net force on the patella in PFP of the patella (29). Imbalanced torque distribution (load sharing) among the VMO, VML and VL in PFP patients

Makhsous, Mohsen

185

Is cartilage thickness different in young subjects with and without patellofemoral pain?  

E-print Network

and individuals with patellofemoral pain. Methods: The articular cartilage thickness of the patella and anterior: On average, males had 22% and 23% thicker cartilage than females in the patella (P at the patella may be one mechanism of patellofemoral pain in male subjects, but is unlikely to be a dominant

Delp, Scott

186

APPLIED SCIENCES Biodynamics  

E-print Network

, it is not clear how individual quadriceps components pull and rotate the patella three dimensionally. The purpose fluoroscopy and in vitro cadaver measurements. Results: Vastus medialis (VM) mainly pulled the patella first and second in the lateral directions. The oblique portion (VMO) of the VM pulled the patella mainly medially

187

Journal of Orti~opaedicResearch 9:91&931 Raven Press, Ltd., New York  

E-print Network

of the trabecular architecture of the human patella. They identified zones of single or mixed orientation within the patella that suggest a sheet-and-rod #12;ANALYZING STRUCTURE OF CANCELLOUSBONE model of the trabecular trabecular archi- tecture and principal stresses calculated from a fi- nite element model of the patella

188

The podocyte-specific inactivation of Lmx1b, Ldb1 and E2a yields new insight into a transcriptional network in podocytes  

E-print Network

; accepted 11 January 2007 Available online 18 January 2007 Abstract Patients with nail-patella syndrome gene in patients with nail-patella syndrome. © 2007 Elsevier Inc. All rights reserved. Keywords: LMX1B; LDB1; E2A; Podocyte; Slit diaphragm; Foot processes; Nail-patella syndrome Introduction Latest since

Witzgall, Ralph - Naturwissenschaftliche Fakultät III

189

Differences in Patellofemoral Kinematics between Weight-Bearing and Non-Weight-Bearing Conditions in Patients with Patellofemoral Pain  

E-print Network

, non-weight-bearing. We compared patellofemoral kinematics measured from the images. The patella than those of the non-maltrackers. In subjects with excessive lateral patellar translation, the patella and 308 (p ¼ 0.001). However, in subjects with normal patellar translation, the patella translated more

Delp, Scott

190

Ccile FAUVELOT , Francesca BERTOZZI  

E-print Network

ABBIATI 1 2 3 Lower genetic diversity in the limpet Patella caerulea on urban coastal structures compared bottom species. We conducted a population genetic analysis on the limpet Patella caerulea sampled30 39 Key words: Patella caerulea; genetic diversity; microsatellites; Adriatic Sea; null alleles

Paris-Sud XI, Université de

191

A Modeling Framework to Estimate Patellofemoral Joint Cartilage Stress In Vivo  

E-print Network

stress in the cartilage of the femur or patella. This article presents a modeling pipeline to estimate squat. Results: The quasistatic finite element simulation reproduced the orientation of the patella highest in the central, lateral aspect of the patella cartilage with a peak of 2.5 MPa. The corresponding

Delp, Scott

192

Menstrual Cycle Mediates Vastus Medialis and Vastus Medialis Oblique Muscle Activity  

E-print Network

to the patella and thus has different functional properties than the proximal VM, which has fibers running more longitudinal to the patella (13,22). Anatomical studies have also shown that while the middle VM and the VMO extension force (13), whereas the VMO medially vectors the patella (18,24) because of its insertion

Griffin, Lisa

193

In vivo patellar tracking induced by individual quadriceps components in individuals with patellofemoral pain  

E-print Network

history: Accepted 28 August 2009 Keywords: Patella Tracking In vivo Kinematics Patellofemoral pain and translation of the patella induced by selective activation of individual quadriceps components would differ in PFP subjects. This could be due to anatomical differences in the VMO insertion on the patella

Makhsous, Mohsen

194

Pour obtenir le grade de DOCTEUR DE L'UNIVERSIT DE GRENOBLE  

E-print Network

/MARIE-MAGDELEINE Th�se dirig�e par Regiane/FORTES-PATELLA et codirig�e par Nicolas/MARCHAND pr�par�e au sein des Grenoble, Pr�sident du jury Mme Regiane FORTES-PATELLA Professeure de Grenoble-INP, Directrice de th�se M/MARIE-MAGDELEINE Th�se dirig�e par Regiane/FORTES-PATELLA et codirig�e par Nicolas/MARCHAND pr�par�e au sein des

Paris-Sud XI, Université de

195

Ballet injuries: the Australian experience.  

PubMed

There is a distinct difference between ballet injuries and sports injuries in general, and the sports medicine physician needs to study the technique of dance and the specific injuries that it may produce in order to treat dancers effectively. In Australia, which is typical of other countries where ballet is performed, ballet injuries include strained lumbar muscles, sprained ankle, Achilles tendinitis, clicking hip, jumper's knee, chondromalacia, stress fractures, patellar subluxation, and other knee and tendon problems. PMID:6652700

Quirk, R

1983-11-01

196

A Randomized, Prospective, Double-Blind Study to Investigate the Effectiveness of Adding DepoMedrol to a Local Anesthetic Injection in Postmeniscectomy Patients With Osteoarthritis of the Knee  

Microsoft Academic Search

Background: Patients with osteoarthritis of the knee are at risk for poorer outcomes after arthroscopic meniscectomy. Intra-articular corticosteroid injections have been shown to be efficacious both in patients with osteoarthritis and postarthroscopy patients. Hypothesis: A postoperative, intra-articular methylprednisolone and lidocaine injection in patients with chondromalacia under- going meniscectomy will improve patient-rated pain and function compared with control patients. Study Design:

Loukas Koyonos; Adam B. Yanke; Allison G. McNickle; Spencer S. Kirk

197

Iliotibial band release as an adjunct to the surgical management of patellar stress fracture in the athlete: a case report and review of the literature  

Microsoft Academic Search

Stress fracture of the patella is rare. In this report, a case of patellar stress fracture occurring in an amateur athlete is presented, and an operative adjunct to the surgical management of this condition is proposed. A review of the English literature identified 21 previous cases of stress fracture of the patella, the majority in young athletes. None of these

Anthony Keeley; Paul Bloomfield; Peter Cairns; Robert Molnar

2009-01-01

198

Diagnosis and Treatment of Patients with Patellofemoral Pain  

Microsoft Academic Search

The patient-athlete with patellofemoral pain requires precise physical examination based on a thorough history. The nature of injury and specific physical findings, including detailed examination of the retinacular structure around the patella, will most accurately pinpoint the specific source of anterior knee pain or instability. Radiographs should include a standard 30° to 45° axial view of the patellae and a

John P. Fulkerson

2002-01-01

199

Patellar position after total knee arthroplasty  

Microsoft Academic Search

Patellar shift, tilt, and rotation were analyzed in 7 cadaveric knee specimens during simulated quadriceps loading, in the intact knee, and after implant reconstruction. Femoral component medialization, lateralization, and external rotation were also investigated. Relative motion of the patella with respect to the femur was measured using an electromagnetic tracking system. The spatial position of the patella did not change

April D Armstrong; Heather J. C Brien; Cynthia E Dunning; Graham J. W King; James A Johnson; David G Chess

2003-01-01

200

Preliminary Study of a Pendulum in Vivo Electromechanical Generator for Orthopedic Implants  

E-print Network

. The prosthesis operating conditions change over time: wear due to friction, the patient body mass changes replacement. Tibia or shinbone Stemmed tibial plate Femoral component Femur or thigh bone Patella or kneecap Patella or kneecap Polyethylene patellar component Stemmed Tibial plate Polyethylene articulating surface

Paris-Sud XI, Université de

201

Accuracy of haptic assessment of patellar symmetry in total knee arthroplasty1  

Microsoft Academic Search

Resection resulting in asymmetrically thick patellar arthroplasty in knee arthroplasty may lead to increased compression forces, wear, fracture, or loss of quadriceps power. Assessing the cut patella between the thumb and forefinger (haptic assessment) represents a convenient way to recognize asymmetry. In 2 test series, 8 orthopedic surgeons evaluated 24 precut solid foam patellae of varying asymmetric thickness by feeling

James K. DeOrio; John P. Peden

2004-01-01

202

Using Real-Time MRI to Quantify Altered Joint Kinematics in Subjects with Patellofemoral Pain and to Evaluate the Effects of a Patellar Brace  

E-print Network

during weight-bearing knee extension. Pain subjects were also imaged while wearing a patellar.Femaleswithpatellofemoral painexhibited increased lateraltranslation ofthe patella for knee flexion angles between 08and 508 (p ¼ 0 the lateral translation of the patella; however, the brace reduced lateral displacement more than the sleeve

Delp, Scott

203

Pressure distribution on the anatomic landmarks of the knee and the effect of kneepads  

Microsoft Academic Search

This study examines stress transmitted to anatomic landmarks of the knee (patella, combined patella tendon and tibial tubercle) while in static kneeling postures without kneepads and while wearing two kneepads commonly worn in the mining industry. Ten subjects (7 male, 3 female) simulated postures utilized in low-seam mines: kneeling in full flexion; kneeling at 90° of knee flexion; and kneeling

William L. Porter; Alan G. Mayton; Susan M. Moore

2010-01-01

204

Accuracy of haptic assessment of patellar symmetry in total knee arthroplasty 1 1 No benefits or funds were received in support of the study  

Microsoft Academic Search

Resection resulting in asymmetrically thick patellar arthroplasty in knee arthroplasty may lead to increased compression forces, wear, fracture, or loss of quadriceps power. Assessing the cut patella between the thumb and forefinger (haptic assessment) represents a convenient way to recognize asymmetry. In 2 test series, 8 orthopedic surgeons evaluated 24 precut solid foam patellae of varying asymmetric thickness by feeling

James K DeOrio; John P Peden

2004-01-01

205

Untrawlable Bottom in Shrimp Statistical Zones of the Northwest Gulf of Mexico  

E-print Network

Bottom Area I used Patella's (1975) estimates for the known amount of area in the Gulf zones (Fig. I). The total for all zones is 30,90 I,394.3 ha or, more simply, about 31 million ha. Patella's estimates

206

LibroRojode losInvertebrados  

E-print Network

Maquetación, egmasa) y SanPrint, S.L. Fotografía de portada: Patella ferruginea Gmelin, 1791. Julio De la Rosa. y Arroyo, M. C. 2008. Patella ferruginea Gmelin, 1791. Pp. 308-319. En: Barea-Azcón, J. M

Maldonado, Manuel

207

THE JOURNAL OF THE ACOUSTICAL SOCIETV OF AMERICA VOLUME 30. NUMBER 5 MAY. 1958 Biological and Medical Acoustics  

E-print Network

. Sectionthroughmid- patella,B. section6.33 cmbelowA, C. section1.27cmbelowB, D. section10.16cm below C (mid-calf). 1. Patella, 2. femur, 3. roedialepicondyle,4. lateral epicondyle,5. gastrocnemiusten- don(lateralhead),6

Illinois at Urbana-Champaign, University of

208

N: 2009 ENAM XXXX Arts et Mtiers ParisTech -Centre de Paris  

E-print Network

: Farid BAKIR Co-encadrement de la thèse : Sofiane KHELLADI T H � S E Jury Mme. Regiane FORTES PATELLA de thèse. Mme. Fortes Patella, merci pour votre présidence et votre disponibilité. Merci, M. Nogueira

Paris-Sud XI, Université de

209

Preprint typeset in JHEP style -HYPER VERSION BNL-NT-07/56 IFUP-TH/2007-36  

E-print Network

, Cambridge CB3 0EH, UK E-mail: b.lucini@swansea.ac.uk Agostino Patella Scuola Normale Superiore, Piazza dei-mail: agostino.patella@sns.it Claudio Pica Physics Department, Brookhaven National Lab Upton, NY 11973-5000, USA

210

Compressive behavior of trabecular bone in the proximal tibia using a cellular solid model  

E-print Network

Posterior cruciate ligament (PCL) Patellar surface of femur Lateral surface of femur Anterior cruciate ligament (ACL) Lateral meniscus Fibular (lateral) Collateral Ligament Femoral component Tibial component Patella component Porous... Posterior cruciate ligament (PCL) Patellar surface of femur Lateral surface of femur Anterior cruciate ligament (ACL) Lateral meniscus Fibular (lateral) Collateral Ligament Femoral component Tibial component Patella component Porous...

Prommin, Danu

2005-11-01

211

Evaluation of a computational model used to predict the patellofemoral contact pressure distribution  

Microsoft Academic Search

One possible cause of patellofemoral pain syndrome is excessive lateral force acting on the patella. Although several treatment methods focus on decreasing the lateral force acting on the patella, the relationship between the lateral force and the patellofemoral contact pressure distribution is unclear. A computational model has been developed to determine how loading variations alter the patellofemoral force and pressure

John J. Elias; David R. Wilson; Robert Adamson; Andrew J. Cosgarea

2004-01-01

212

Fast identification & modelling of osteoarthritic holes in the human knee with contour interpolated radial basis functions.  

PubMed

In this article, we propose a new method for the fast 3D reconstruction of simulated osteoarthritic holes in a human patella. Initially, clean patella slices were extracted from MRI scans of the knee using Region-Based Segmentation (region-growing) and Bounding Box techniques. Osteoarthritic (OA) holes were then simulated in the patella slices. Our contour interpolation/RBF (CI/RBF) method was then used to detect the hole automatically and reconstruct 3D models of both the patella and OA hole separately. The method presented here proves fast, reliable and efficient for reconstructing a 3D model of the patella from MRI images with an extremely low error of 0.33%. PMID:24110718

Javaid, Zarrar; Unsworth, Charles P; Boocock, Mark; McNair, Peter

2013-01-01

213

Mygalomorph spiders (Araneae: Dipluridae) from the Lower Cretaceous Crato Lagerstätte, Araripe Basin, north-east Brazil  

E-print Network

setae). Abbreviations used in the figures. 1, 2, 3, 4, walking leg numbers; bl1, bl2, book-lung covers 1 and 2; car, carapace; ch, chelicera; cx, coxa; f, fovea; fe, femur; mt, metatarsus; op, opisthosoma; ot, ocular tubercle; pa, patella; pa or, palpal... 4Æ10 (basal segment 1Æ24, middle segment 1Æ35, distal segment 1Æ48). Podomere lengths: pedipalp femur 1Æ98; Leg 1: femur 3Æ05, patella 2Æ92, tibia 3Æ24, metatarsus 2Æ84, tarsus 1Æ92; Leg 2: trochanter 0Æ67, femur 3Æ05, patella 2Æ14, tibia 2Æ86...

Selden, Paul A.; Casado, Fabio da Costa; Mesquita, Marisa Vianna

2006-01-01

214

BY ALYSSA SCHNUGG Staff Writer  

E-print Network

the standards of renovations of the Mississippi Department of Archives and History. See VENTRESS on Page 3B at the junction of the kneecap (patella) and thighbone (femur), is one of the most common problems in sports

Tchumper, Gregory S.

215

How I Manage Osteochondritis Dissecans.  

ERIC Educational Resources Information Center

Osteochondritis dissecans, a lesion found most often on the femur at the knee joint, occurs most frequently in active adolescents. This article describes treatment for preadolescents, adolescents, and adults. Osteochondritus dissecans of the patella is also presented. (MT)

DiStefano, Vincent J.

1986-01-01

216

Meniscus Tears  

MedlinePLUS

... of three bones: the thighbone (femur), the shinbone (tibia), and the kneecap (patella), as well as the ... that connects them. Between your femur and your tibia are two C-shaped discs of cartilage that ...

217

Internet Journal of Medical Update, Vol. 3, No. 2, Jul-Dec 2008 Original Work Copyrighted by Dr. Arun Kumar Agnihotri. All right reserved  

E-print Network

for gender determination. Fingerprints were obtained from 115 normal healthy adults and comprised of 57 male shape,5 femoral head,6 foot and shoe dimensions,7 patella,8 teeth,9 and radial and ulnar bone lengths.10

Nagurka, Mark L.

218

Total knee replacement for patellofemoral disease.  

PubMed

This study evaluates the technical results and outcomes of total knee replacement (TKR) in a group of patients with isolated patellofemoral disease based on the amount of bone loss and patella subluxation seen at the time of surgery. Thirty-three TKRs in 25 patients comprised the study group. All patients had radiographic evidence of isolated end-stage disease in the patellofemoral joint and had cemented tri-compartmental knee replacements. All patellae could be resurfaced. Average follow-up was 5.2 years (range: 3.8-8.4 years). Average Knee Society Scores was 62 preoperatively and 96 at final follow-up. There was no correlation in outcomes related to either the amount of patellar wear, size of the patella, or amount of subluxation of the patella. Total knee replacement is an effective means of managing end-stage arthritis of the patellofemoral joint. PMID:16262008

Dalury, David F

2005-10-01

219

Accuracy of haptic assessment of patellar symmetry in total knee arthroplasty.  

PubMed

Resection resulting in asymmetrically thick patellar arthroplasty in knee arthroplasty may lead to increased compression forces, wear, fracture, or loss of quadriceps power. Assessing the cut patella between the thumb and forefinger (haptic assessment) represents a convenient way to recognize asymmetry. In 2 test series, 8 orthopedic surgeons evaluated 24 precut solid foam patellae of varying asymmetric thickness by feeling the patella between thumb and forefinger, without visualization. Of 384 responses, in 73.2% asymmetry was underestimated, 10.4% assessments were exact, and in 16.4% asymmetry was overestimated. Specifically, 35.9% were correct within 1 mm, 60.7% within 2 mm, 81% within 3 mm, and 91.4% within 4 mm. The thickest half of the patella was correctly identified in 90.6% of responses. Haptic assessment of patellar symmetry is a useful technique in knee arthroplasty. PMID:15284985

DeOrio, James K; Peden, John P

2004-08-01

220

Vibration arthrometry in the patients with failed total knee replacement  

Microsoft Academic Search

This is a preliminary research on the vibration arthrometry of artificial knee joint in vitro. Analyzing the vibration signals measured from the accelerometer on patella, there are 2 speed protocols in knee kinematics: 1) 20\\/s, the signal is called \\

Ching-Chuan Jiang; Ju-Hong Lee; Tung-Tai Yuan

2000-01-01

221

Opto-numerical procedures supporting dynamic lower limbs monitoring and their medical diagnosis  

NASA Astrophysics Data System (ADS)

New optical full-field shape measurement systems allow transient shape capture at rates between 15 and 30 Hz. These frequency rates are enough to monitor controlled movements used e.g. for medical examination purposes. In this paper we present a set of algorithms which may be applied for processing of data gathered by fringe projection method implemented for lower limbs shape measurement. The purpose of presented algorithms is to locate anatomical structures based on the limb shape and its deformation in time. The algorithms are based on local surface curvature calculation and analysis of curvature maps changes during the measurement sequence. One of anatomical structure of high medical interest that is possible to scan and analyze, is patella. Tracking of patella position and orientation under dynamic conditions may lead to detect pathological patella movements and help in knee joint disease diagnosis. Therefore the usefulness of the algorithms developed was proven at examples of patella localization and monitoring.

Witkowski, Marcin; Kujawi?ska, Malgorzata; Rapp, Walter; Sitnik, Robert

2006-01-01

222

21 CFR 888.3550 - Knee joint patellofemorotibial polymer/metal/metal constrained cemented prosthesis.  

Code of Federal Regulations, 2010 CFR

...component may be attached to the resected patella either with a metallic screw or bone cement. All stemmed metallic components within this generic type are intended for use with bone cement (§ 888.3027). (b) Classification. Class III....

2010-04-01

223

Modified pre-curved patellar basket plate, reconstruction of the proper length and position of the patellar ligament--a biomechanical analysis.  

PubMed

Biomechanical properties of basket plate fixation for fracture dislocation in the distal part of the patella were studied on 22 fresh-frozen lower extremities (human cadaveric knees). The patella and the patellar ligament with the proximal tibia were removed. A comminuted fracture of the distal part of the patella was created with a chisel. The fractured patella, patellar ligament and tibial tuberosity of each specimen were fixed with a basket plate and mounted into the jaws of the testing machine. The measured load to failure was 421.66+/-45.90 N, which is approximately 70% higher than the results in other studies. The results of the measurements verified the results of finite element analysis. The modified precurved patellar basket plate developed in this study showed improved performance compared to the pre-existing fixation methods. PMID:17433694

Krkovic, M; Bombac, D; Balazic, M; Kosel, F; Hribernik, M; Senekovic, V; Brojan, M

2007-06-01

224

Renal phenotype in heterozygous Lmx1b knockout mice ( Lmx1b +\\/? ) after unilateral nephrectomy  

Microsoft Academic Search

The nail-patella syndrome (NPS) is a rare autosomal-dominant disorder which is caused by loss-of-function mutations in the\\u000a transcription factor LMX1B. NPS is characterized by dysplastic nails, absent or hypoplastic patellae, minor skeletal abnormalities\\u000a and nephropathy (in 20–40% of the cases), which is the most severe aspect of the disorder. The current data suggest that genetic\\u000a modifiers in the outbred human

Sabine Endele; Sabine Klein; Sabine Richter; Tina Molter; Kerstin Amann; Bernd Klanke; Ralph Witzgall; Randy L. Johnson; Karl F. Hilgers; Andreas Winterpacht

2007-01-01

225

Determination of Safe Depth of Pin Penetration for Repair of Distal Femoral Physeal Fractures in Immature Dogs: A Comparison of Normograde and Retrograde Pin Placement  

Microsoft Academic Search

Objective—The purpose of this study was to determine the depth that implants may be safely placed into the distal femoral epiphysis (DFE) for the repair of distal femoral physeal fractures.\\u000aStudy Design—The depth of the DFE was related to the radiographic thickness of the patella in this experimental study.\\u000aAnimals or Sample Population—Twenty immature canine cadavers.\\u000aMethods—Patella thicknesses were measured

Dragan Lorinson; Darryl L. Millis; Ronald M. Bright

1997-01-01

226

Differences in patellofemoral contact stresses between mobile-bearing and fixed-bearing total knee arthroplasties: a dynamic in vitro measurement  

Microsoft Academic Search

Introduction  Anterior knee pain is one of the most common problems after total knee arthroplasty (TKA). Mobile-bearing designs should improve\\u000a patella tracking with a reduced rate of patella tilt as well as reduced patellofemoral contact stresses and improve knee flexion.\\u000a The aim of this dynamic in vitro investigation was to evaluate the changes of patellofemoral contact stresses after TKA using\\u000a fixed

Adrian Skwara; Carsten O. Tibesku; Sven Ostermeier; Christina Stukenborg-Colsman; Susanne Fuchs-Winkelmann

2009-01-01

227

Hallux valgus and hallux flexus associated with cerebral palsy: analysis and treatment.  

PubMed

Hallux valgus and hallux flexus associated with cerebral palsy foot deformity may be due to equinovalgus and/or metatarsus primus adductus or combinations of these. Occasionally the condition occurs in equinovarus feet. Hallux flexus or "dorsal bunion" is usually due to a weak extensor hallucis longus, overpull of the anterior tibial muscle on the first metatarsal and spasticity or contracture of the flexor hallucis longus or brevis. A weak peroneus longus muscle has not caused this deformity. The condition is usually predictable in the growing child if all factors related to gait, collagen stability and foot alignment are observed. Treatment includes soft-tissue and bone realignment. Release of the adductor hallucis, lateral collateral ligaments of the metatarsophalangeal joint, plication of the medial capsule and of the abductor hallucis and centralization of the extensor hallucis longus will realign the first ray. The flexor hallucis longus is transferred to athe extensor hallucis longus proximal to the metatarsophalangeal joint and the anterior tibial tendon is transferred to the second metatarsal. An osteotomy at the base of the first metatarsal and at the base of the proximal phalanx will realign the skeleton. Twenty-six great toes in 16 patients have been observed for two to 20 years. The correction has been maintained without arthrodesis of the metatarsophalangeal joint except where chondromalacia occurred. Once the pattern of deformity is evident, progression is unrelenting and treatment is indicated in order to prevent chondromalacia of the articular cartilage. PMID:7249469

Goldner, J L

1981-06-01

228

Implant design and techniques for patellar resurfacing in total knee arthroplasty.  

PubMed

There are two basic techniques for resurfacing of the patella in total knee arthroplasty. The inset patellar component recesses a circular dome with a single fixation peg into a reamed patella while the onlay component is placed onto the cut surface of patella. Onlay patellar components have a wide variety of shapes, designs, and methods of fixation. There are differences in technique and possible complications with the inset and onlay patellar components. However, neither method has proved to be superior. Fixation of an onlay patellar component is usually with cement, but successful cementless porous-coated designs exist. Fixation of an all-polyethylene patellar component occurs by cementing a component with either a single central peg or three smaller peripheral pegs; although one method is not preferred over the other, there have been reports of breakage with three pegs. The design and fabrication of these components are important to prevent peg breakage with repeated shear stress. There are few clinical data implicating the different shapes or methods of patella component fixation with the complications of anterior knee pain, wear, patella fracture, and component breakage. Attention to detail during surgery is likely the most critical factor to the success of patellar resurfacing in total knee arthroplasty. PMID:15116612

Lachiewicz, Paul F

2004-01-01

229

Automatic anatomical structures location based on dynamic shape measurement  

NASA Astrophysics Data System (ADS)

New image processing methods and active photonics apparatus have made possible the development of relatively inexpensive optical systems for complex shape and object measurements. We present dynamic 360° scanning method for analysis of human lower body biomechanics, with an emphasis on the analysis of the knee joint. The anatomical structure (of high medical interest) that is possible to scan and analyze, is patella. Tracking of patella position and orientation under dynamic conditions may lead to detect pathological patella movements and help in knee joint disease diagnosis. The processed data is obtained from a dynamic laser triangulation surface measurement system, able to capture slow to normal movements with a scan frequency between 15 and 30 Hz. These frequency rates are enough to capture controlled movements used e.g. for medical examination purposes. The purpose of the work presented is to develop surface analysis methods that may be used as support of diagnosis of motoric abilities of lower limbs. The paper presents algorithms used to process acquired lower limbs surface data in order to find the position and orientation of patella. The algorithms implemented include input data preparation, curvature description methods, knee region discrimination and patella assumed position/orientation calculation. Additionally, a method of 4D (3D + time) medical data visualization is proposed. Also some exemplary results are presented.

Witkowski, Marcin; Rapp, Walter; Sitnik, Robert; Kujawinska, Malgorzata; Vander Sloten, Jos; Haex, Bart; Bogaert, Nico; Heitmann, Kjell

2005-09-01

230

Automatic Insall-Salvati ratio measurement on lateral knee x-ray images using model-guided landmark localization  

NASA Astrophysics Data System (ADS)

The Insall-Salvati ratio (ISR) is important for detecting two common clinical signs of knee disease: patella alta and patella baja. Furthermore, large inter-operator differences in ISR measurement make an objective measurement system necessary for better clinical evaluation. In this paper, we define three specific bony landmarks for determining the ISR and then propose an x-ray image analysis system to localize these landmarks and measure the ISR. Due to inherent artifacts in x-ray images, such as unevenly distributed intensities, which make landmark localization difficult, we hence propose a registration-assisted active-shape model (RAASM) to localize these landmarks. We first construct a statistical model from a set of training images based on x-ray image intensity and patella shape. Since a knee x-ray image contains specific anatomical structures, we then design an algorithm, based on edge tracing, for patella feature extraction in order to automatically align the model to the patella image. We can estimate the landmark locations as well as the ISR after registration-assisted model fitting. Our proposed method successfully overcomes drawbacks caused by x-ray image artifacts. Experimental results show great agreement between the ISRs measured by the proposed method and by orthopedic clinicians.

Chen, Hsin-Chen; Lin, Chii-Jeng; Wu, Chia-Hsing; Wang, Chien-Kuo; Sun, Yung-Nien

2010-11-01

231

Patellar position after total knee arthroplasty: influence of femoral component malposition.  

PubMed

Patellar shift, tilt, and rotation were analyzed in 7 cadaveric knee specimens during simulated quadriceps loading, in the intact knee, and after implant reconstruction. Femoral component medialization, lateralization, and external rotation were also investigated. Relative motion of the patella with respect to the femur was measured using an electromagnetic tracking system. The spatial position of the patella did not change with standardized total knee arthroplasty (P <.05). After malpositioning of the femoral component, patellar rotation also did not change (P >.05); however, patellar tilt was altered by femoral component external rotation malposition (P <.05), and patellar shift was affected by all femoral component malpositions (P <.05). The spatial position of the patella relative to the femoral shaft was changed with any femoral component malposition, suggesting that the soft tissues were abnormally tensioned. This could result in subsequent wear on the patellar component and, therefore, early failure. PMID:12820089

Armstrong, April D; Brien, Heather J C; Dunning, Cynthia E; King, Graham J W; Johnson, James A; Chess, David G

2003-06-01

232

Surgical reconstruction of severe patellofemoral maltracking.  

PubMed

Dysfunction of the patellofemoral mechanism presents in many ways. Results from different realignment procedures show great variability in patient outcome. A surgical technique is presented that attempts to correct all the abnormalities of patellofemoral maltracking. The procedure consists of a lateral release, a vastus medialis (obliquus) tendon advancement, and a tibial tubercle transfer. Along with being moved medially, the tubercle also is moved distally to correct patella alta and elevated anteriorly to reduce patellofemoral joint reaction forces. One hundred seven knees in 84 patients were reviewed. Fifty-five percent of patients had frank dislocation. The remaining patients had anterior knee pain and had abnormal patella tracking on examination. The mean followup was 5.6 years. Seventy-nine percent of patients had a good to excellent functional outcome and 84% of patients stated they would have the operation again. Two patients with marked generalized ligamentous laxity had recurrent dislocation of the patella. PMID:15021145

Palmer, Simon H; Servant, Christopher T J; Maguire, John; Machan, Simone; Parish, Erin N; Cross, Mervyn J

2004-02-01

233

Genitopatellar syndrome: a case report of a rare entity with 11 years of follow-up.  

PubMed

Genitopatellar syndrome is one of the syndromes described in the last decade. It is characterized by agenesis of the corpus callosum, absent or hypoplastic patellae, extremity contractures, skeletal anomalies, urogenital anomalies, and facial dysmorphic features. While writing this report, only 15 cases have been reported in the literature. The etiology, clinical features, management, and natural history of this syndrome are not yet well established. Past reports in the literature have not been able to identify the exact genetic etiology but it somewhat coincides with nail patella syndrome and short patella syndrome. We would like to introduce this terminology to the orthopedic community and highlight the clinical features of the genitopatellar syndrome. To the best of our knowledge, this is a single case report with the longest follow-up of 11 years in the literature. PMID:22568963

To, Michael; Negandhi, Rajiv; Cheung, Kenneth; Cheung, Wai Yuen; Chow, Wang

2013-07-01

234

The knee: Surface-coil MR imaging at 1. 5 T  

SciTech Connect

Seven normal knees (in five volunteers) and seven injured knees (in seven patients) were examined by high-resolution magnetic resonance (MR) imaging at 1.5 T with a surface coil. Seven medial meniscal tears, three anterior cruciate ligament tears, one posterior cruciate ligament avulsion, an old osteochondral fracture, femoral condylar chondro-malacia, and one case of semimembranous tendon reinsertion were identified. MR images correlated well with recent double-contrast arthrograms or results of surgery. All tears were identified in both the sagittal and coronal planes. Because of its ability to demonstrate small meniscal lesions and ligamentous injuries readily, MR imaging with a surface coil may eventually replace the more invasive arthrography.

Beltran, J.; Noto, A.M.; Mosure, J.C.; Weiss, K.L.; Zuelzer, W.; Christoforidis, A.J.

1986-06-01

235

Communicating pork value to the retailer  

E-print Network

muscles were cut into pork cubes (UPC 3196). Fresh hams (IMPS 401) were first skinned and defatted. Os coxae, femur, patella and tibia were removed yielding a boneless ham. The ham then was separated into a boneless tip roast (UPC 3410), boneless top... muscles were cut into pork cubes (UPC 3196). Fresh hams (IMPS 401) were first skinned and defatted. Os coxae, femur, patella and tibia were removed yielding a boneless ham. The ham then was separated into a boneless tip roast (UPC 3410), boneless top...

Lorenzen, Carol Lee

2012-06-07

236

Clinical, roentgenographic, and scintigraphic results after interruption of the superior lateral genicular artery during total knee arthroplasty  

SciTech Connect

Forty-eight patients treated by primary bilateral simultaneous total knee arthroplasty, in which one knee had a lateral release and the other did not, were evaluated clinically and roentgenographically from one to 12 years postoperatively. Thirty of these patients also had a technetium-99 bone scan. Mean clinical scores at the last follow-up examination were 90 for both groups. Roentgenographically, there were no subluxations, dislocations, or fractures in either group. There were two metal-backed patellae (one in each group) with signs of polyethylene wear and developed debris. Bone scans showed no difference between the two groups and no signs of osteonecrosis of the patella.

Ritter, M.A.; Keating, E.M.; Faris, P.M. (Center for Hip and Knee Surgery, Mooresville, IN (USA))

1989-11-01

237

Midterm results of mobile-bearing total knee arthroplasty in patients younger than 65 years.  

PubMed

This study evaluated 117 patients younger than 65 years (average, 56 years) in whom mobile-bearing total knee arthroplasties were inserted. All patellae were resurfaced with a mobile-bearing patella implant. Followup averaged 102 months (range, 60-171 months). The average knee score was 91 points, with a pain score of 27 points (possible 30 points). There were eight (7%) revision surgeries in this series, with four malpositioned implants, one infection, and one case of osteolysis. Two patients had bearing revisions for bearing dislocation and polyethylene wear. Survivorship at 14 years was 88%. PMID:11550865

Sorrells, R B; Stiehl, J B; Voorhorst, P E

2001-09-01

238

Medial patellofemoral ligament reconstruction with semitendinosus autograft.  

PubMed

Patellar instability is a common complaint after traumatic dislocation of the patella. Traumatic dislocation always leads to tearing of the medial patellofemoral ligament (MPFL). Treatment consists of recovery from the traumatic injury, followed by reconditioning and physical therapy to strengthen the dynamic stabilizers of the patella. In patients with recurrent instability, detailed evaluation of the cause is required to determine the needed interventions. In patients with an incompetent MPFL and recurrent instability, reconstruction is indicated, along with other procedures to address other contributing factors. This article details our technique for MPFL reconstruction using semitendinosus autograft, which can be performed alone or in concert with other realignment procedures. PMID:24400192

Wylie, James D; Burks, Robert T

2013-01-01

239

Medial Patellofemoral Ligament Reconstruction With Semitendinosus Autograft  

PubMed Central

Patellar instability is a common complaint after traumatic dislocation of the patella. Traumatic dislocation always leads to tearing of the medial patellofemoral ligament (MPFL). Treatment consists of recovery from the traumatic injury, followed by reconditioning and physical therapy to strengthen the dynamic stabilizers of the patella. In patients with recurrent instability, detailed evaluation of the cause is required to determine the needed interventions. In patients with an incompetent MPFL and recurrent instability, reconstruction is indicated, along with other procedures to address other contributing factors. This article details our technique for MPFL reconstruction using semitendinosus autograft, which can be performed alone or in concert with other realignment procedures. PMID:24400192

Wylie, James D.; Burks, Robert T.

2013-01-01

240

Genetic Disorders of Glomerular Basement Membranes  

Microsoft Academic Search

This review provides current information about glomerular disorders that arise directly from inherited abnormalities in extracellular matrix proteins intrinsic to the glomerular basement membrane (Alport syndrome, thin basement membrane nephropathy, HANAC syndrome and Pierson syndrome). The authors also discuss disorders involving genetic defects in cellular proteins that result in structural defects in glomerular basement membranes (MYH9-related disorders, nail-patella syndrome).

Clifford E. Kashtan; Yoav Segal

2011-01-01

241

Fax +41 61 306 12 34 E-Mail karger@karger.ch  

E-print Network

. In the kidney, the LIM homeodomain transcription factor LMX1B is specifically synthesized in podocytes, and mutations in LMX1B lead to nail-patella syn- drome and the associated nephropathy. Other transcrip- tion the synthesis of these pro- teins. Our review will highlight the current knowledge on gene regulation

Witzgall, Ralph - Naturwissenschaftliche Fakultät III

242

Influence of patellar thickness on results of total knee arthroplasty: does a residual bony patellar thickness of  

PubMed

With patellar thickness averaging 24.0 mm and 21.9 mm in Singapore men and women undergoing total knee arthroplasty, achievement of precut thickness is difficult if the recommended residual bony thickness of 15 mm is maintained. We retrospectively compared the clinical outcome of 56 patellae resurfaced patellae resurfaced >12 mm (mean residual thickness, 13.7 mm). Both groups were comparable in terms of demographic characteristics, presentation, precut patellar thickness, and operative details (P> .05). Knee scores (P= .627), extensor mechanism function (P= .625), and postoperative range of motion (P= .344) were comparable. Differences in the overall (P= .167) and patellar (P= .061) complication rates as determined by chi-square test on the SPSS 10.0 program were not significant, although there were 4 patella-related complications in group 2. Increased patella-related complications may be associated with an excessive patellar composite of the patellofemoral articulation. A residual patellar thickness of <12 mm did not appear to affect the clinical outcome in this series. PMID:11805925

Koh, J S B; Yeo, S J; Lee, B P H; Lo, N N; Seow, K H; Tan, S K

2002-01-01

243

Biomechanical analysis of parameters related to patellofemoral pain syndrome  

Microsoft Academic Search

From multifactorial etiology, patellofemoral pain syndrome (PFPS) affects 7 to 15% of the population, causes diffuse pain, anterior or behind patella and is exacerbated during functional activities. However, both the evaluation process and the evolution of treatment are based fundamentally in the reporting of pain by the patient and in the functional disability. A correct diagnostic of the disorder would

Heloyse U. Kuriki; Danilo Santos Catelli; Fábio M. Azevedo; Carlos Eduardo de Albuquerque; Eduardo Alexandre Loth; Rúben F. Negrão Filho; Neri Alves; Brasil Carlos

244

Electrical stimulation of vastus medialis and stretching of lateral thigh muscles in patients with patello-femoral symptoms  

Microsoft Academic Search

Thirty patients with unilateral patello-femoral symptoms and a hypotrophic vastus medialis muscle were treated with transcutaneous electrical stimulation of the vastus medialis obliquus and stretching of the lateral thigh muscles twice daily for 10 weeks. Before and after treatment the position of the patella at fixed knee flexion angles and the area of the vastus medialis and vastus lateralis muscles

S. Werner; H. Arvidsson; I. Arvidsson; E. Eriksson

1993-01-01

245

Microcephaly, short stature, and developmental delay associated with a chemotactic defect and transient hypogammaglobulinaemia in two brothers  

Microsoft Academic Search

Two brothers presented with unusual facial features, microcephaly, developmental delay, and severe postnatal growth retardation. They both developed eczema in infancy and have had recurrent infections. Additional physical findings in both boys included hypogonadism, flexion contractures, hypoplastic patellae, and scoliosis. Their facial similarity was striking with sloping foreheads, beaked noses, large, protruding ears, and micrognathia. Low levels of serum gammaglobulins

B Say; N Barber; G C Miller; S E Grogg

1986-01-01

246

ETIOLOGY OF PATELLOFEMORAL PAIN SYNDROME: A PROXIMAL LINK TO A DISTAL PROBLEM  

Microsoft Academic Search

Patellofemoral pain syndrome (PFPS) is one of the most common, but least understood, knee disorders. Fulkerson (1997) believes that pathology may result from an excessive valgus force being applied to the patella. Researchers have historically examined quadriceps strength and neuromuscular activity and knee kinematics. However, results from these works have not provided conclusive answers. Powers (2003) has theorized that other

Lori Ann Bolgla

2005-01-01

247

Examination of Porous-CoatedPatellar Components and Analysis of the Reasons for Their Retrieval  

E-print Network

of a wide variety of designs were examined for type and amount of tissue ingrowth and for wear and creep bone stock that fracture of the patella becomes a very real possibility, or over-stuffing of the joint reasons often reveal the presence of particulate polyethylene wear debris at the margins of the bone

248

Fracture of the femoral component associated with polyethylene wear and osteolysis after total knee arthroplasty  

Microsoft Academic Search

Fracture of the femoral component associated with polyethylene wear and osteolysis after total knee arthroplasty (TKA) has not been well reported before. A 63-year-old man with osteoarthritis of the right knee underwent TKA with a New Jersey LCS Knee, with cementing on the tibia and patella but not on the femoral component. After 42 months, in addition to wearing of

Chun-Hsiung Huang; Chyun-Yu Yang; Cheng-Kung Cheng

1999-01-01

249

This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research  

E-print Network

regions at 7 anatomical locations in 21 human cadaver patellae. For our analysis, T2 relaxation time's personal copy Prediction of glycosaminoglycan content in human cartilage by age, T1r and T2 MRI K.E. Keenan of Bioengineering, Stanford University, Stanford, CA, USA a r t i c l e i n f o Article history: Received 25 June

Delp, Scott

250

Reducing Capacity in U.S. Managed An analysis of overcapacity and the cost of a vessel  

E-print Network

Rogers, Eric Thunberg, John Walden, Will Daspit, Brad Stenberg, Steve Freese, Jim Hastie, Stephen Holiman. Kirkley, John M. Ward, James Nance, Frank Patella, Karyl Brewster-Geisz, Chris Rogers, Eric Thunberg, John Walden, Will Daspit, Brad Stenberg, Steve Freese, Jim Hastie, Stephen Holiman, and, Mike Travis NOAA

251

Soft Tissue Restraints to Lateral Patellar Translation in the Human Knee  

Microsoft Academic Search

The purpose of this investigation was to identify and quantify the soft tissue restraints, both medially and laterally, to lateral patellar translation. These restraints to lateral patellar translation at 20° of knee flexion were tested biomechanically on a universal testing instrument in nine fresh-frozen cadaveric knees. After preconditioning the tissues, the patella of each intact knee was translated laterally to

Stephen M. Desio; Robert T. Burks; Kent N. Bachus

1998-01-01

252

Bipolar infrapatellar tendon rupture.  

PubMed

Traumatic patella alta in children occurs either distal to the patellar tendon as a tibial tubercle apophyseal fracture or proximally as an osteochondral sleeve fracture of the inferior patellar pole. Acute surgical exploration in a pediatric case of a knee extensor mechanism rupture revealed both proximal and distal (bipolar) patellar tendon pathology. PMID:7790483

Berg, E E

1995-01-01

253

Trace metals with seasonal considerations in coastal algae and molluscs from Beirut, Lebanon  

Microsoft Academic Search

Twelve species of intertidal algae and molluscs from Ras Beirut, Lebanon have been investigated for their heavy metal content. Atomic absorption spectrophotometric analysis showed that the algae and molluscs concentrated similar levels of most metals. However, of the twelve organisms, Brachydontes variabilis had the highest copper, Patella coerulea and Colpomenia sinuosa had the highest iron, and Pinctada radiata had the

J. G. Shiber

1980-01-01

254

Baseline Trace Metals in Seagrass, Algae, and Mollusks in a Southern Tyrrhenian Ecosystem (Linosa Island, Sicily)  

Microsoft Academic Search

Trace elements were analyzed in organisms collected at five sampling stations along coastal areas of Linosa Island, Sicily\\u000a (southern Tyrrhenian Sea, Italy). Concentrations of Cd, Cr, Cu, Pb, and Zn were measured in Posidonia oceanica L. Delile tissues, the two brown algae Padina pavonica (L.) Thivy and Cystoseira sp., and the two gastropod mollusks Monodonta turbinata Born and Patella caerulea

Marcelo Enrique Conti; Beatrice Bocca; Marta Iacobucci; Maria Grazia Finoia; Mauro Mecozzi; Anna Pino; Alessandro Alimonti

2010-01-01

255

Patellofemoral ligament reconstruction in a patient with Rubinstein-Taybi syndrome.  

PubMed

Recurrent dislocation of patella may occur in patients with ligament laxity. Method of treatment in this condition is controversial but patellofemoral ligament reconstruction is the most accepted method. We present a patient with Rubinstein-Taybi syndrome and recurrent patellar dislocation who managed successfully by patellofemoral ligament reconstruction. PMID:24901727

Mirzatolooei, Fardin

2014-01-01

256

Arthroscopic extraarticular reconstruction of the medial patellofemoral ligament with gracilis tendon autograft - surgical technique.  

PubMed

The standard approach to reconstruct the medial patellofemoral ligament (MPFL) is by mini-open incision at its patellar insertion and femoral origin. At the medial patella rim, the MPFL insertion may be visualized in most cases by dissection during surgery. On the femur, it is more difficult to localize the MPFL remnants by a mini-open incision due to soft tissue covering the anatomical origin. Therefore, the femoral MPFL origin is usually identified by intraoperative lateral fluoroscopy. However, the insertion and origin of the MPFL at the patella and femur might be directly visualized using an arthroscopic extraarticular approach from the knee joint through a window of the synovial layer. This is especially helpful on the femoral side but also at the patella to find the individual anatomical MPFL footprints. Arthroscopic extraarticular reconstruction may then be performed using one additional medial mid-parapatellar portal. The major advantages of this technique are an individualized anatomical procedure, which is minimal invasive and cosmetically appealing. The aim of this study was to describe the arthroscopic extraarticular approach to the MPFL insertion at the patella and origin at the femur through synovial windows and to explain the procedure of arthroscopic MPFL reconstruction with a gracilis tendon autograft. Level of evidence Expert opinion, surgical technique, Level V. PMID:22484369

Siebold, Rainer; Borbon, Carlo Angelo V

2012-07-01

257

Evaluation of patellar height and measurement methods after valgus high tibial osteotomy  

Microsoft Academic Search

Several controversies exist regarding the surgical difficulties and the results of total knee arthroplasty performed after failed valgus high tibial osteotomy (HTO), and the main subject is the change in patellar height that results as patella baja or infera. The purpose of this retrospective study was to evaluate patellar height after valgus HTO and the measurement methods that were actually

Hayrettin Kesmezacar; Rifat Erginer; Tahir Ogut; Aksel Seyahi; Muharrem Babacan; Yuksel Tenekecioglu

2005-01-01

258

Patellar tendon length following opening wedge high tibial osteotomy using an external fixator with particular reference to later total knee replacement  

Microsoft Academic Search

The aim of this retrospective study was to examine a cohort of patients who had undergone high tibial osteotomy (HTO) using the method of opening wedge hemicallotasis, and who later required conversion to total knee replacement (TKR). The incidence of patella infra and any technical difficulties encountered during TKR operation were examined.A consecutive series of 76 valgus osteotomies in 65

J. Kitson; A. E. Weale; A. S. Lee; A. G. MacEachern

2001-01-01

259

Proximal medial tibial biplanar retrotubercle open wedge osteotomy in medial knee arthrosis  

Microsoft Academic Search

The patellar tendon length changes and patella infera occurs in medial open wedge osteotomies. We hypothesized that patellar tendon length in the sagittal plane would not change in a proximal medial tibial biplanar retrotubercle open wedge osteotomy. Proximal medial tibial biplanar retrotubercle open wedge osteotomies were conducted on 23 knees of 22 patients; the mean patient age was 59±7years (range,

Irfan Esenkaya; Koray Unay

260

Aggressive Quadriceps Loading Can Induce Noncontact Anterior Cruciate Ligament Injury  

Microsoft Academic Search

Background: The force responsible for noncontact anterior cruciate ligament (ACL) injuries remains controversial. The patella tendon to tibial shaft angle causes an anterior tibial shear force with quadriceps activation.Hypothesis: An aggressive quadriceps contraction can injure the ACL.Methods: The authors characterized noncontact ACL injury and kinematics with aggressive quadriceps loading. Thirteen freshfrozen knees were potted in a jig held in 20

Gene Demorat; Paul Weinhold; Troy Blackburn; Steven Chudik; William Garrett

2004-01-01

261

Evaluation of the Roux-Elmslie-Trillat procedure for knee extensor realignment  

Microsoft Academic Search

One method for correction of patellofemoral malalign ment in acute and recurrent dislocations and sublux ations of the patella involves a lateral retinacular release, medial capsular reefing, and medial displace ment of the infrapatellar tendon insertion. The proce dure was originally described by Roux and later mod ified and popularized by Elmslie and Trillat. It allows adequate evaluation and easy

Jay S. Cox

1982-01-01

262

Axial computed tomography of the patellofemoral joint with and without quadriceps contraction  

Microsoft Academic Search

Computed tomography was used to analyze the patellofemoral relationship during the first 60° of knee flexion in patients with chronic patellofemoral pain syndrome (49 knees) and a healthy control group (15 knees). The patellofemoral joints were imaged axially through the center of the patella articular cartilage with the knee flexed 0°, 0° with maximal quadriceps muscle contraction, 30°, and 60°.

R. M. Biedert; C. Gruhl

1997-01-01

263

COMPARAÇÃO DO ALINHAMENTO ANATÔMICO DE MEMBROS INFERIORES ENTRE INDIVÍDUOS SAUDÁVEIS E INDIVÍDUOS COM TENDINOSE PATELAR  

Microsoft Academic Search

Comparison of the anatomical alignment of lower limbs between healthy individuals and those with patellar tendinosis Background: Tendinosis is a degenerative condition in tendons caused by excessive stress. If not treated adequately, it may develop into total rupture of the tendon. Misalignment of the patella and\\/or structural abnormalities of the foot are considered risk factors for patellar tendinosis. However, no

S. T. Fonseca; Luciana De Michelis Mendonça

264

Articular Cartilage Contact Pressure after Tibial Tuberosity TransferA Cadaveric Study  

Microsoft Academic Search

Medial transfer of the tibial tuberosity has been commonly used for treatment of recurrent dislocation of the patella and patellofemoral malalignment. In this study, six fresh human cadaveric knees were used. Static intrajoint loads were recorded using Fuji Prescale pressure-sensitive film for contact pressure and contact area determination in a closed kinetic chain knee testing protocol. Peak pressures, average contact

Ryosuke Kuroda; Helen Kambic; Antonio Valdevit; Jack T. Andrish

2001-01-01

265

Clinical characteristics of patellar disorders in young athletes  

Microsoft Academic Search

The clinical histories of 50 young athletes who com plained of patellar instability or pain were analyzed, and their physical findings were compared to those of 50 controls. The patients were divided into three groups, based on their symptoms. Analysis of their physical findings confirmed the validity of these divi sions. Those who complained of frank dislocation of the patella

Bruce Reider; John L. Marshall; Russell F. Warren

1981-01-01

266

Effect of Q-angle on patellar positioning and thickness of knee articular cartilages.  

PubMed

The purpose of the present study was to investigate whether an increased quadriceps angle (Q-angle) has an effect on patellar positioning and/or the thickness of the medial and lateral tibiofemoral and patellofemoral articular cartilage and menisci, in a group of young asymptomatic individuals. These individuals were detected in a previous study with a decreased anatomical cross-sectional area of the vastus medialis and lateralis as a result of an increased Q-angle. Patellar positioning and the thickness of the articular cartilages were determined in 19 asymptomatic male individuals with high Q-angle (HQ-angle) (18.5° ± 2.6°) using magnetic resonance imaging (MRI). Seventeen male counterparts with low Q-angle (10.1° ± 1.9°) were used for comparison. The position of the patella was determined by measuring the sulcus angle, the lateral patella tilt, the patella-lateral condyle index and the bisect offset (BSO) with the quadriceps relaxed. The BSO, was also measured with the quadriceps under maximum isometric voluntary contraction. The thickness of the articular cartilages of the lateral and medial femoral condyles, the tibial condyles, the patellar facets and the menisci were also measured. Our data revealed that healthy individuals with HQ-angle are unlikely to demonstrate any changes in the position of the patella and/or the thickness of the knee articular cartilages. The decreased anatomical area of the vastus medialis and an almost equally atrophied vastus lateralis, which was previously observed in this group of individuals may prevent in part the misalignment of the patella and early wear of the tibiofemoral and patellofemoral articular cartilages. PMID:20798938

Tsakoniti, Aikaterini E; Mandalidis, Dimitris G; Athanasopoulos, Spyros I; Stoupis, Christoforos A

2011-03-01

267

[Chronic patellofemoral instability].  

PubMed

Chronic patellofemoral instability may lead to pain and early osteoarthrosis. Recurrent dislocations of the patella, lateral subluxation and chronic dislocation are summarized under this generic term. There are five different factors which may be responsible of the development of chronic patellofemoral instability: 1) elongation of the medial patellofemoral ligament (MPFL), 2) patella alta, 3) increased distance between tibial tuberosity and trochlea groove (TTTG) distance, 4) trochlea dysplasia and 5) torsional malalignment. To rule out these factors clinical examination, radiological diagnostics (luxation, subluxation in the Defilée view, trochlea morphology, patella alta) and magnetic resonance imaging (MRI) of TTTG distance and trochlea morphology are crucial. The indications of operative treatment are chronic pain with subluxation, chronic dislocation and recurrent dislocation. Currently the former frequently and universally used lateral release is only indicated in cases of subluxation and positive tilt. Biomechanical studies have shown that a lateral release will otherwise increase patellofemoral instability. The choice of the surgical technique depends on the factors underlying patellofemoral instability, the conditions of growth plate and cartilage damage. Among the different surgical options proximal and distal realignment procedures are differentiated. In cases of MPFL elongation and mild passive instability a medial reefing might be successful. In cases of MPFL elongation, high passive instability up to 30° of flexion (with or without trochlear dysplasia) MPFL reconstruction may be the treatment of choice. A trochleoplasty is rarely indicated. This treatment may be considered in cases of high grade trochlea dysplasia and passive instability at more than 30° of flexion. If the TTTG distance is increased (>20 mm) or in cases of patella alta distal realignment with tibial tubercle transfer should be considered. This operation might also be useful in the presence of lateral cartilage damage as an anteromedialization of the patella. PMID:22588526

Petersen, W; Forkel, P; Achtnich, A

2012-05-01

268

Patellofemoral contact patterns before and after total knee arthroplasty: an in vitro measurement  

PubMed Central

Background Patellofemoral complications are one of the main problems after Total Knee Arthroplasty (TKA). Retropatellar pressure distribution after TKA can contribute to these symptoms. Therefore we evaluated retropatellar pressure distribution subdivided on the ridge, medial and lateral surface on non-resurfaced patella before and after TKA. Additionally, we analyzed axial femorotibial rotation and quadriceps load before and after TKA. Methods Seven fresh frozen cadaver knees were tested in a force controlled knee rig before and after TKA (Aesculap, Tuttlingen, Germany, Columbus CR) while isokinetic flexing the knee from 20° to 120° under weight bearing. Ridge, medial and lateral retropatellar surface were defined and pressure distribution was dynamically measured while quadriceps muscles and hamstring forces were applied. Aside axial femorotibial rotation and quadriceps load was recorded. Results There was a significant change of patella pressure distribution before and after TKA (p?=?0.004). In physiological knees pressure distribution on medial and lateral retropatellar surface was similar. After TKA the ridge of the patella was especially in higher flexion grades strongly loaded (6.09 +/?1.31 MPa) compared to the natural knee (2.92 +/?1.15 MPa, p?patella maltracking. Changing the design of the prosthesis or a special way of patella shaping might increase the conformity of the patella to trochlea to maintain natural contact patterns. PMID:23802712

2013-01-01

269

A subdivision-based parametric deformable model for surface extraction and statistical shape modeling of the knee cartilages  

NASA Astrophysics Data System (ADS)

Subdivision surfaces and parameterization are desirable for many algorithms that are commonly used in Medical Image Analysis. However, extracting an accurate surface and parameterization can be difficult for many anatomical objects of interest, due to noisy segmentations and the inherent variability of the object. The thin cartilages of the knee are an example of this, especially after damage is incurred from injuries or conditions like osteoarthritis. As a result, the cartilages can have different topologies or exist in multiple pieces. In this paper we present a topology preserving (genus 0) subdivision-based parametric deformable model that is used to extract the surfaces of the patella and tibial cartilages in the knee. These surfaces have minimal thickness in areas without cartilage. The algorithm inherently incorporates several desirable properties, including: shape based interpolation, sub-division remeshing and parameterization. To illustrate the usefulness of this approach, the surfaces and parameterizations of the patella cartilage are used to generate a 3D statistical shape model.

Fripp, Jurgen; Crozier, Stuart; Warfield, Simon K.; Ourselin, Sébastien

2006-03-01

270

Ultrastrukturelle Untersuchungen zur Morphologie und Genese der Spermien von Archaeogastropoda  

NASA Astrophysics Data System (ADS)

The sperm cells of Patella coerulea (Patellacea), Monodonta turbinata, and Gibbula tumida (Trochacea) were investigated by means of transmission electron microscopy. They belong to the primitive type (sensu Franzén) and have more features in common with primitive Bivalvia sperms than with Neritacea. Their head contains an apical acrosome and a roundish nucleus followed by 4 or 5 mitochondria and a centriolar apparatus which consists of two centrioles, one of which bears a flagellum. The sperm cells of Monodonta and Gibbula are very similar to each other and differ mainly in size; Patella exhibits more differences (very small acrosome, subacrosomal space, variable number of spherical mitochondria (origin of spermic dimorphism ?). The development of the sperm cells shows no peculiarities.

Kohnert, R.; Storch, V.

1983-03-01

271

Isolated revision of failed metal-backed patellar components: outcome with minimum 4-year follow-up.  

PubMed

Several reports document high failure rates of metal-backed patellar components, but few report the outcome of revising these components to all-polyethylene, cemented implants. At a mean 87.2-month follow-up, we describe a series of 36 patients (40 knees) who underwent isolated metal-backed patellar revision to a cemented, all-polyethylene patellar component. After the patellar revision, 5 patients (6 knees) underwent additional surgery, but no patellar components required revision. The additional surgeries were performed at an average of 77.6 months after patellar revision and included 3 tibial insert exchanges for polyethylene wear, 2 revisions of femoral and tibial components for osteolysis, and 1 realignment procedure for recurrent subluxation of the patella. We conclude that revision of a failed metal-backed patellar component to a cemented, all-polyethylene patella is a durable, successful procedure. PMID:16376254

Burke, W Vincent; Ammeen, Deborah J; Engh, Gerard A

2005-12-01

272

Bilateral, spontaneous and simultaneous rupture of the quadriceps tendon in chronic renal failure and secondary hyperparathyroidism. Report of five cases.  

PubMed

Bilateral and simultaneous rupture of the quadriceps tendon of the knee without significant trauma in five patients, two males and three females, with chronic renal failure and secondary hyperparathyroidism is reported. Ruptures of the extensor mechanism are relatively rare injuries. Unilateral rupture is more common. Bilateral, simultaneous and spontaneous rupture is a very rare condition and only eleven cases have been reported in patients with a number of systemic diseases. Two cases have also been described in healthy subjects. The following points contribute to the diagnosis of quadriceps tendon rupture: 1) sudden pain and inability to extend the knee, 2) a palpable defect above the patella, 3) lateral x-rays with technique for soft tissue, reveal a defect and anterior tilting of the proximal pole of the patella. Operative repair of the ruptured tendon was the treatment in all our cases and gave excellent results. PMID:1785948

Provelegios, S; Markakis, P; Cambouroglou, G; Choumis, G; Dounis, E

1991-01-01

273

The medial patellofemoral ligament revisited: an anatomical study.  

PubMed

The purpose of this study was to provide a comprehensive description of the anatomy of the medial patellofemoral ligament (MPFL). The anterior and medial aspects of 4 unpreserved and 16 preserved cadaveric human knees were dissected with particular attention being paid to the relationship of the various layers to one another and to the place of the MPFL within these layers. We confirmed that the MPFL is a distinct structure lying within layer II. Its bulk varies considerably between individuals but not from side to side in a given individual. The visualisation, attachments, and gross morphology of the ligament are described. The attachments of the MPFL and the orientation of its fibres suggest that it may have a role in limiting lateral excursion of the patella. The common attachment of the tendon of the vastus medialis muscle and the ligament to the superomedial patella suggests that there may be a dynamic element to such a stabilising function. PMID:8536025

Feller, J A; Feagin, J A; Garrett, W E

1993-01-01

274

Distal realignment (tibial tuberosity transfer).  

PubMed

Although tibial tuberosity (TT) transfer has for many years been the basis of many protocols for the management of patellar instability, the role of pure medial transfer in particular appears to be declining. In contrast, the greater recognition of the importance of patella alta as a predisposing factor to recurrent patellar dislocation has resulted in a resurgence in the popularity of distal TT transfer. When TT transfer is performed, the direction and amount of transfer is based on the patellar height and the lateralization of the TT relative to the trochlear groove. Patellar height is best assessed on a lateral radiograph with the knee in flexion using a ratio that uses the articular surface of the patella in relation to the height above the tibia. Assessment of lateralization of the TT relative to the trochlear groove can be made using either computed tomography or magnetic resonance imaging scans. PMID:22878656

Feller, Julian Ashley

2012-09-01

275

Reconstruction of a ruptured patellar tendon using ipsilateral semitendinosus and gracilis tendons with preserved distal insertions: two case reports  

PubMed Central

Background Acute patellar tendon ruptures with poor tissue quality. Ruptures that have been neglected are difficult to repair. Several surgical techniques for the repair of the patellar tendon have been reported, however, these techniques remain difficult because of contractures, adhesions, and atrophy of the quadriceps muscle after surgery. Case presentation We report the cases of 2 Japanese patients (Case 1: a 16-year-old male and Case 2: a 43-year-old male) with patellar tendon ruptures who were treated by reconstruction using semitendinosus-gracilis (STG) tendons with preserved distal insertions. Retaining the original insertion of the STG appears to preserve its viability and provide the revascularization necessary to accelerate healing. Both tendons were placed in front of the patella, in a figure-of-eight fashion, providing stability to the patella. Conclusion Both patients recovered near normal strength and stability of the patellar tendon as well as restoration of function after the operation. PMID:24010848

2013-01-01

276

Double-Bundle Medial Patellofemoral Ligament Reconstruction With a Single Patellar Tunnel  

PubMed Central

Medial patellofemoral ligament (MPFL) reconstruction is an established method to prevent patellofemoral instability. Nevertheless, the anatomy and the biomechanical behavior of native MPFL are still under investigation, but in recent years they have become more defined. We propose a technique for MPFL reconstruction based on the results of recent anatomic studies regarding the patellar insertion of the MPFL. A double-bundle MPFL is reconstructed by use of the semitendinosus tendon passed through a single patellar tunnel, which crosses the patella from the midpoint of its medial border until its superolateral corner is reached. This method permits a strong patellar fixation, potentially reducing the risk of patellar fracture compared with double–patellar tunnel techniques. Moreover, it requires no fixation devices at the patella and only a single interference screw on the femoral side. PMID:24400189

Zanon, Giacomo; Marullo, Matteo; Benazzo, Francesco

2013-01-01

277

Locomotor advantages of Neandertal skeletal morphology at the knee and ankle  

Microsoft Academic Search

We quantified Neandertal knee extensor and ankle plantarflexor moments to determine whether di?erences between Neandertal and recent human skeletal morphology represent important functional di?erences. Neandertal skeletal di?erences in the patella, tibial tuberosity, and calcaneus were used to modify a computer model of recent humans to calculate the moment arms and moments of Neandertal knee extensor and ankle plantarflexor muscles. We

M. Melissa

278

The podocyte-specific inactivation of Lmx1b, Ldb1 and E2a yields new insight into a transcriptional network in podocytes  

Microsoft Academic Search

Patients with nail-patella syndrome, which among other symptoms also includes podocyte-associated renal failure, suffer from mutations in the LMX1B gene. The disease severity among patients is quite variable and has given rise to speculations on the presence of modifier genes. Promising candidates for modifier proteins are the proteins interacting with LMX1B, such as LDB1 and E47. Since human kidney samples

Hani Suleiman; Daniel Heudobler; Anne-Sarah Raschta; Yangu Zhao; Qi Zhao; Irmgard Hertting; Helga Vitzthum; Marcus J. Moeller; Lawrence B. Holzman; Reinhard Rachel; Randy Johnson; Heiner Westphal; Anne Rascle; Ralph Witzgall

2007-01-01

279

The human LMX1B gene: transcription unit, promoter, and pathogenic mutations  

Microsoft Academic Search

LMX1B is a LIM-homeodomain transcription factor required for the normal development of dorsal limb structures, the glomerular basement membrane, the anterior segment of the eye, and dopaminergic and serotonergic neurons. Heterozygous loss-of-function mutations in LMX1B cause nail patella syndrome (NPS). To further understand LMX1B gene regulation and to identify pathogenic mutations within the coding region, a detailed analysis of LMX1B

Jennifer A. Dunston; Jeanette D. Hamlington; Jayshree Zaveri; Elizabeth Sweeney; Julie Sibbring; Catherine Tran; Maria Malbroux; John P. O'Neill; Roger Mountford; Iain McIntosh

2004-01-01

280

A new in vivo technique for determination of femoro-tibial and femoro-patellar 3D kinematics in total knee arthroplasty.  

PubMed

Aim was to develop an in vivo technique which allows determination of femoro-tibial and of femoro-patellar 3D-kinematics in TKA simultaneously. The knees of 20 healthy volunteers and of eight patients with TKA (PCR, rotating platform) were investigated. Kinematics analysis was performed in an open MR-system at different flexion angles with external loads being applied. The TKA components were identified using a 3D-fitting technique, which allows an automated 3D-3D-registration of the TKA. Femoro-patellar and femoro-tibial 3D-kinematics were analyzed by image postprocessing. The validity of the postprocessing technique demonstrated a coefficient of determination of 0.98 for translation and of 0.97 for rotation. The reproducibility yielded a coefficient of variation (CV%) for patella kinematics between 0.17% (patello-femoral angle) and 6.8% (patella tilt). The femoro-tibial displacement also showed a high reproducibility with CV% of 4.0% for translation and of 7.1% for rotation. While in the healthy knees the typical screw-home mechanism was observed, a paradoxical anterior translation of the femur relative to the tibia combined with an external rotation occurred after TKA. Fifty percent of the TKA's experienced a condylar lift-off of >1mm predominately on the medial side. Regarding patellar kinematics significant changes were found in both planes in TKA with an increased patella height in the sagittal plane and patella tilt and shift in the transversal plane. The results demonstrate that the presented 3D MR-open based method is highly reproducible and valid for image acquisition and postprocessing and provides--for the first time--in vivo data of 3D-kinematics of the tibio-femoral and simultaneously of the patello-femoral joint during knee flexion. PMID:17475270

von Eisenhart-Rothe, R; Vogl, T; Englmeier, K-H; Graichen, H

2007-01-01

281

Multicenter-study of operative treatment of intraligamentous tears of the anterior cruciate ligament in children and adolescents  

Microsoft Academic Search

Tears of the anterior cruciate ligament in skeletally immature patients were operated with four different methods and their outcome compared to each other. Sixty-eight patients (33 males, 35 females), mean 12.5 years, were treated in four different centers from 1984 to 2001. Twenty-eight patients underwent the ACL-reconstruction with hamstring grafts, 16 patients with bone–patella–bone autografts, 12 patients with quadriceps grafts and

F. Gebhard; A. Ellermann; F. Hoffmann; J.-H. Jaeger; N. F. Friederich

2006-01-01

282

Sewage pollution and extinction risk: an endangered limpet as a bioindicator?  

Microsoft Academic Search

The mollusc Patella ferruginea, endemic to the Mediterranean, is the most endangered marine species on the list of the European Council Directive 92\\/43\\/EEC\\u000a and it is under serious risk of extinction. In spite of the low abundances and restricted distribution of this limpet, important\\u000a populations have been found in the harbour of Ceuta, north Africa. The main objective of the

F. Espinosa; J. M. Guerra-García; J. C. García-Gómez

2007-01-01

283

Association familiale d'une transposition pénoscrotale et diphallia (pénis double) à une aplasie rotulienne  

Microsoft Academic Search

Background. - Diphallia and penoscrotal transposition are rare, generally sporadic, abnormalities.Case reports. - Case 1: A 2-1\\/2-month old boy was admitted in hospital because he suffered from complete penoscrotal transposition, with moderate hypospadias for which he was operated on. Examination at the age of 6 years showed hypoplastic and dislocated patellae. Case 2: A 2-month-old boy, brother of case 1,

H Dodat; D Rosenberg; I James-Pangaud

1995-01-01

284

Coordination of murine limb muscle, skeleton and connective tissue development by Lmx1b  

Microsoft Academic Search

The underlying genetic defects of a congenital disease Nail-Patella Syndrome are loss-of-function mutations in the LMX1B gene. Lmx1b encodes a LIM-homeodomain transcription factor that is expressed specifically in the dorsal limb bud mesenchyme. Gain- and loss-of-function experiments suggest that Lmx1b is both necessary and sufficient to specify dorsal limb patterning. However, how Lmx1b coordinates patterning of the dorsal tissues in

Ying Li

2009-01-01

285

Non-Contact Evaluation of Osmosis-Induced Shrinkage and Swelling Behavior of Articular Cartilage In-Situ Using High-Frequency Ultrasound  

Microsoft Academic Search

The aim of the present study was to use high?frequency ultrasound for the investigation of the transient osmosis?induced free shrinkage?swelling behaviors of normal articular cartilage in situ. Full?thickness cartilage?bone specimens were prepared from normal bovine patellae. The transient shrinkage and swelling strains of the cartilage induced by changing the bathing solution between physiological saline (0.15 M) and hypertonic saline (2 M) were

Q. Wang; Y. P. Zheng

2006-01-01

286

The influence of patellar bracing on patellar and knee load-distribution and kinematics: an experimental cadaver study  

Microsoft Academic Search

The aim of this study was to analyze the biomechanical consequences of patella bracing in order to evaluate possible mechanisms\\u000a supporting its clinical application. The hypothesis is that the patellar bracing reduces patellofemoral pressure by influencing\\u000a patellar and knee kinematics, and load distribution. Physiologic isokinetic knee extension motions were simulated on ten human\\u000a knee cadaver specimens using a knee kinematic

Michael Bohnsack; Andre Halcour; Phillip Klages; Arne Wilharm; Sven Ostermeier; Oliver Rühmann; Christof Hurschler

2008-01-01

287

Retropatellar contact characteristics in total knee arthroplasty with and without patellar resurfacing  

Microsoft Academic Search

Total knee replacement with and without patellar resurfacing was performed in 6 cadaver specimens. The contact pressure and\\u000a contact area between femur and patella was measured at 60° of flexion. In comparison to specimens without resurfacing the\\u000a specimens with small size resurfacing showed a significant decrease in contact area, whereas average and maximum pressure\\u000a were unchanged. In specimens with medium

S. Fuchs; G. Schütte; H. Witte; D. Rosenbaum

2000-01-01

288

Effects of the Balanced Gap Technique on Femoral Component Rotation in TKA  

Microsoft Academic Search

Femoral component rotation from a total knee prosthesis can be determined by either a measured resection technique or a balanced\\u000a gap technique. With the balanced gap implantation technique, femoral component rotation can vary freely within the restrictions\\u000a produced by soft tissue structures. Because internal rotation might cause patella problems, the effect of ligament releases\\u000a on femoral component rotation in a

Petra J. C. Heesterbeek; Wilco C. H. Jacobs; Ate B. Wymenga

2009-01-01

289

Dissemination of metals from a failed patellar component made of titanium-base alloy  

Microsoft Academic Search

Complications related to the patella are the most common problems in total knee arthroplasty and major reasons for revision surgery. Among patellofemoral problems, metal-to-metal contact between patellar and femoral components is the worst. We measured levels of titanium, aluminum, and vanadium in serum and urine samples and compared these measures from cases in which metal-to-metal contact of the patellar component

Shinro Takai; Nobuyuki Yoshino; Yoshiaki Kusaka; Yoshinobu Watanabe; Yasusuke Hirasawa

2003-01-01

290

Some geographical components in population dynamics: Possibilities and realities in some littoral species  

NASA Astrophysics Data System (ADS)

Inability to repopulate adequately probably sets the northern limit of Chthamalus montagui, Patella vulgata, P. aspera, Gibbula umbilicalis and Monodonta lineata, creates unstables populations in adjacent regions, and may result in greater sizes and life-spans in the north. Incomplete data support expectations of summer breeding in the north, winter breeding in the south. Poor years in the north do not result from gonad failure.

Lewis, J. R.; Bowman, R. S.; Kendall, M. A.; Williamson, P.

291

Patello-femoral and tibio-femoral contact forces during kicking type of activity  

SciTech Connect

In this paper patello-femoral and tibia-femoral contact forces during kicking type of activity is presented by means of a dynamic model of the knee joint which includes tibio-femoral and patello-femoral articulations, and the major ligaments of the joint. The model shows that the patella can be subjected to very large transient patello-femoral contact forces during a strenuous lower limb activity such as kicking even under conditions of small knee-flexion angles.

Engin, A.E. [Univ. of South Alabama, Mobile, AL (United States); Tumer, S.T. [Middle East Technical Univ., Ankara (Turkey)

1996-12-31

292

The Coffin-Siris syndrome.  

PubMed

We report a white female infant with typical features of Coffin-Siris syndrome including thick eyebrows, flat nasal bridge, anteverted, wide nose tip, generalised hypertrichosis, scalp hypotrichosis, absence of the fifth fingernails and toenails, absence of the distal phalanges of the fifth fingers and of the second to fifth toes, small patellae, inguinal hernia, and sucking and feeding difficulties. There was decreased fetal activity and intrauterine growth retardation. PMID:2352263

Qazi, Q H; Heckman, L S; Markouizos, D; Verma, R S

1990-05-01

293

Mosaic tetrasomy 9p in a girl with multiple congenital anomalies: cytogenetic and molecular-cytogenetic studies  

Microsoft Academic Search

We report on a 16-year-old girl with tetrasomy 9p mosaicism. Clinical investigations disclosed a malformation syndrome with\\u000a craniofacial abnormalities, dysplasia of the right clavicle, short neck with cervical ribs, patella dislocation, Dandy-Walker\\u000a malformation, mental retardation and blindness. Karyotype analysis of blood lymphocytes indicated an additional marker in\\u000a the size of a C-group chromosome with a large heterochromatic block in 88%

M. Stumm; H. Tönnies; U. Mandon; A. Götze; P. Krebs; P. F. Wieacker

1999-01-01

294

Regional variations in human patellar trabecular architecture and the structure of the proximal patellar tendon enthesis.  

PubMed

Proximal patellar tendinopathy occurs as an overuse injury in sport and is also characteristic of ankylosing spondylitis patients. It particularly affects the posteromedial part of the patellar tendon enthesis, although the reason for this is unclear. We investigated whether there are regional differences in the trabecular architecture of the patella or in the histology of the patellar tendon enthesis that could suggest unequal force transmission from bone to tendon. Trabecular architecture was analysed from X-rays taken with a Faxitron radiography system of the patellae of dissecting room cadavers and in magnetic resonance images of the knees of living volunteers. Structural and fractal analyses were performed on the Faxitron digital images using MatLab software. Regional differences at the enthesis in the thickness of the uncalcified fibrocartilage and the subchondral plate were evaluated histologically in cadaveric material. The radiological studies showed that the quantity of bone and the apparent trabecular thickness in the patella were greatest medially, and that in the lateral part of the patella there were fewer trabeculae which were orientated either antero-posteriorly or superiorly inferiorly. The histological study showed that the uncalcified fibrocartilage was most prominent medially and that the subchondral plate was thinner laterally. Overall, the results indicate that mechanical stress at the proximal patellar tendon enthesis is asymmetrically distributed and greater on the medial than on the lateral side. Thus, we suggest that the functional anatomy of the knee is closely related to regional variations in force transmission, which in turn relates to the posteromedial site of pathology in proximal patellar tendinopathy. PMID:16420378

Toumi, H; Higashiyama, I; Suzuki, D; Kumai, T; Bydder, G; McGonagle, D; Emery, P; Fairclough, J; Benjamin, M

2006-01-01

295

The trisomy 8 syndrome: two additional mosaic cases  

PubMed Central

Two patients with trisomy 8 mosaicism, confirmed by trypsin-Giemsa banding are described. While the majority of patients with this aneuploidy have been mosaics, the phenotypes of the complete and mosaic trisomies closely resemble each other. Mosaic trisomy 8 results in specific clinical findings which include skeletal dysplasia, particularly absent patellae, deep furrowing of the soles of the feet, and periarticular changes resulting in camptodactyly and progressive limitation of joint mobility. Images PMID:4443989

Crandall, B. F.; Bass, H. N.; Marcy, S. M.; Glovsky, M.; Fish, C. H.

1974-01-01

296

Consideration of growth factors and bio-scaffolds for treatment of combined grade II MCL and ACL injury  

Microsoft Academic Search

The literature suggests that a Grade II medial collateral ligament (MCL) injury in combination with anterior cruciate ligament\\u000a (ACL) injury will heal naturally and not compromise patient outcome following ACL reconstruction. Evidence based on bone-patella\\u000a tendon-bone autograft use is stronger than evidence supporting anatomically placed soft tissue graft use. Current ACL reconstruction\\u000a practices make greater use of soft tissue grafts,

Natasha Anoka; John Nyland; Mark McGinnis; Dave Lee; Mahmut Nedim Doral; David N. M. Caborn

297

Comparative uptake from sea water and tissue distribution of 60Co in marine mollusks  

Microsoft Academic Search

Five different species of marine mollusks, Mytilus galloprovincialis Lmk., Tapes decussatus L., Cerastoderma (Cardium) edule (L.), Donax vittatus (da Costa) and Patella vulgata L., were exposed to ⁶°Co-labelled sea water under laboratory conditions. After a 1-mo exposure, tested species reached different whole-body ⁶°Co concentration factors (CF) over radioactive sea water of 73 +\\/- 27, 22 +\\/- 10, 84 +\\/- 25,

Fernando P. Carvalho

1987-01-01

298

Medial Patellofemoral Ligament Reconstruction Using Hamstring Autograft in Children and Adolescents  

PubMed Central

We introduce an anatomic reconstruction technique for the medial patellofemoral ligament using a free hamstring autograft in skeletally immature patients. We dock the 2 ends of the graft in the superior-medial patella using sockets and secure the femoral graft attachment in a socket tunnel distal to the physis. This technique minimizes the risk of injury to the growth plate and still enables accurate and successful anatomic positioning of the hamstring autograft. PMID:23875142

Ladenhauf, Hannah N.; Berkes, Marschall B.; Green, Daniel W.

2013-01-01

299

Patellofemoral contact pressure following high tibial osteotomy: a cadaveric study  

Microsoft Academic Search

Patella infera is a known complication of high tibial osteotomy (HTO) that can cause anterior knee pain due to excessive stresses\\u000a associated with abnormal patellofemoral (PF) joint biomechanics. However, the translation of these abnormal biomechanics to\\u000a native cartilage pressure has not been explored. The present study was designed to compare the PF contact pressures of three\\u000a different HTOs in a

Karl Stoffel; Craig Willers; Omar Korshid; Markus Kuster

2007-01-01

300

The Coronal Plane High Tibial Osteotomy. Part 1: A Clinical and Radiographic Analysis of Intermediate Term Outcomes  

Microsoft Academic Search

The coronal plane high tibial osteotomy is a novel technique that is used to treat tibiofemoral malalignment. The authors\\u000a hypothesize that the coronal plane high tibial osteotomy is (1) efficacious in treating both varus and valgus tibiofemoral\\u000a malalignment; (2) does not alter the slope of the proximal tibia; and (3) does not alter the relationship between the patella\\u000a and tibial

Keith M. Baumgarten; Stephen Fealy; Stephen Lyman; Thomas L. Wickiewicz

2007-01-01

301

The influence of open and closed high tibial osteotomy on dynamic patellar tracking: a biomechanical study  

Microsoft Academic Search

High tibial osteotomy (HTO) can cause alterations in patellar height, depending on the surgical technique, the amount of correction\\u000a and the postoperative management. Alterations in patella location after HTO may lead to postoperative complications. However,\\u000a information on changes in dynamic patellar kinematics following HTO is very limited. We conducted a biomechanical study, to\\u000a analyze the effect of open (OWO) and

Robert Gaasbeek; R. T. C. Welsing; Marco Barink; Nico Verdonschot; Albert van Kampen

2007-01-01

302

Effect of errors in the identification of anatomical landmarks on the accuracy of Q angle values  

Microsoft Academic Search

Objective. To determine the effect of error in the location of the anterior superior illiac spine, and the centres of the patella and tibial tuberosity, on the measured value of the quadriceps angle.Background. The quadriceps angle is said to be relevant in the etiology and management of patello-femoral pain. However, the issues around measurement accuracy have not been reported.Methods. Errors

Christopher Nester

2001-01-01

303

Quadriceps cross-sectional area changes in young healthy men with different magnitude of Q angle  

Microsoft Academic Search

Abstract Knee pain and dysfunction has been often associated with an ineffective pull of the patella by the vastus medialis relative to the lateralis, particularly in individuals with knee joint malalignment. Such changes,in muscular,behaviour may,be attributed,to muscle inhibition and\\/or atrophy that precede the onset of symptoms. The aim of this study was to investigate possible effects of knee joint malalignment,

Aikaterini E. Tsakoniti; Christoforos A. Stoupis; Spyros I. Athanasopoulos

2008-01-01

304

Traumatic Bone Bruises in the Athlete's Knee  

PubMed Central

Context: Mobile water within the bone marrow is a physiological phenomenon that is identifiable on magnetic resonance (MR) imaging, and signal changes can result from blood pooling, reactive hyperemia, edema, and microfracture. When these MR lesions are associated with an acute traumatic event, the findings are referred to as bone bruises and so represent a unique manifestation of injury. This review discusses bone bruises in anterior cruciate ligament (ACL) tears, patella dislocations, occult fractures, and contusions. Methods: A PubMed search of the literature from 1982 to December 2009 was conducted with the terms knee and bone bruise. Results: Bone bruises are associated with ACL tears, patella dislocations, occult fractures, and contusions. For each injury, a unique pattern of bone bruising is found on MR imaging, which results from the acute trauma. When acute trauma produces a subchondral lesion with low T1-weighted and high T2-weighted signal intensity, the resulting bony contusion is best described as a bone bruise. Conclusions: Bone marrow edema is identified using MR imaging and may result from traumatic or atraumatic causes. Bone bruises can be characterized by their pattern at presentation, by the mechanism of injury, and by their associated injuries. This type of bone edema can accompany contact and noncontact ACL ruptures as well as patella dislocations. Although increased marrow edema can be associated with an occult fracture, the long-term significance of these lesions is unclear. PMID:23015967

DeAngelis, Joseph P.; Spindler, Kurt P.

2010-01-01

305

A case of patellar fractures in monozygotic twin gymnasts  

PubMed Central

We present a case of near identical patellar fractures in adolescent monozygotic twins who are both high-level competitive gymnasts. These patients presented 14 months apart with almost identical history and clinical findings. Both had an intense training regime involving over 30 hours per week of load-bearing exercise. Clinical and radiological examinations suggested avulsion or sleeve fracture of the inferior pole of the patella with minimal displacement. Diagnoses of patellar stress fracture with avulsion of the distal pole and symptomatic bipartite patella could not be reliably excluded. Both fractures were treated conservatively with immobilisation of the knee in extension. An excellent functional result was observed in both patients with return to full activity at 8 weeks. This is the first published case of identical injury to the patella in monozygotic twins. A significant genetic influence on bone mineral density (BMD) has been reported and low BMD is associated with increased susceptibility to fracture. These injuries corroborate a genetic influence on susceptibility to fracture. There is a requirement for further work to investigate genetic factors influencing susceptibility to fracture. PMID:22691448

2012-01-01

306

Maternal Dietary Intake of Polyunsaturated Fatty Acids Modifies the Relationship between Lead Levels in Bone and Breast Milk1,2  

PubMed Central

Whereas dietary fats are known to influence bone mineral density, little is known about their effect on the skeletal stores of lead that are a pervasive source of fetal and infant lead exposure from heightened mobilization during pregnancy and lactation. This cross-sectional study examined the potential influence of maternal dietary intake of saturated and unsaturated fats on the relationship of lead levels in bone and breast milk during lactation. Lead was measured in blood, breast milk, and bone (patella and tibia) at 1 mo postpartum in 310 women in Mexico City. Dietary nutrient intake was assessed using a validated FFQ. Multivariate linear regression analyses were used to study the influence of dietary saturated and unsaturated fats on the association between bone and breast milk lead. In multivariate models that included both the dietary intake of SFA and PUFA, an interquartile range increase in patella lead [~20 µg/g (0.097 µmol/g)] was associated with a 24% (95% CI = 5–43) higher increase in breast milk lead in women in the lowest tertile of PUFA intake compared with those in the highest tertile of PUFA intake. Monounsaturated fatty acids did not modify the relationship between lead levels in patella and breast milk. In conclusion, higher maternal dietary intake of PUFA may limit the transfer of lead from bone to breast milk. PMID:18156407

Arora, Manish; Ettinger, Adrienne S.; Peterson, Karen E.; Schwartz, Joel; Hu, Howard; Hernandez-Avila, Mauricio; Tellez-Rojo, Martha Maria; Wright, Robert O.

2008-01-01

307

Effect of mechanical convection on the partitioning of an anionic iodinated contrast agent in intact patellar cartilage.  

PubMed

To determine if mechanical convection accelerates partitioning of an anionic contrast agent into cartilage while maintaining its ability to reflect the glycosaminoglycan (GAG) content in contrast-enhanced computed tomography (CECT) of cartilage. Bovine patellae (N?=?4) were immersed in iothalamate and serially imaged over 24?h of passive diffusion at 34°C. Following saline washing for 14?h, each patella was serially imaged over 2.5?h of mechanical convection by cyclic compressive loading (120N, 1?Hz) while immersed in iothalamate at 34°C. After similar saline washing, each patella was sectioned into 15 blocks (n?=?60) and contrast concentration per time point as well as GAG content were determined for each cartilage block. Mechanical convection produced 70.6%, 34.4%, and 16.4% higher contrast concentration at 30, 60, and 90?min, respectively, compared to passive diffusion (p?

Entezari, Vahid; Bansal, Prashant N; Stewart, Rachel C; Lakin, Benjamin A; Grinstaff, Mark W; Snyder, Brian D

2014-10-01

308

Patellar options in revision total knee arthroplasty.  

PubMed

There are numerous options that need to be considered by the surgeon at the time of revision total knee arthroplasty (TKA). One needs to consider the reason for the revision, the type of patella in place, and the length of time the patella has been in place. The surgeon also needs to consider the status of the patellar bone stock, the stability of the patellar component (well-fixed or loose), and the component type (cemented or metal-backed). Assuming that the existing prosthesis is not metal-backed and has minimal PE wear, then it is preferable to retain a well-fixed all-PE cemented patellar button. However, if the button is metal-backed, then it probably is best to remove the button and replace it with an all-PE domed patellar component. Assuming more than 8 mm of patellar bone stock is remaining, it usually is best to cement an all-PE dome-shaped patella. However, if less than 8 mm is remaining, then that patient can be left with a patelloplasty, recognizing that this individual is going to continue with a high likelihood of anterior knee pain, subluxation, and poor functional results. In that situation, it may be preferable to consider a bone stock augmentation. PMID:14646744

Rorabeck, Cecil H; Mehin, Ramin; Barrack, Robert L

2003-11-01

309

A cladistic phylogeny of the family Patellidae (Mollusca: Gastropoda)  

PubMed Central

A phylogenetic hypothesis for the patellid limpets is reconstructed by cladistic analysis of morphological characters from 37 species, representing all but one of the living members of the family. Characters included in the analysis are derived from shell shape and microstructure, headfoot and pallial complex, radula and sperm. The species fall into four clades, providing the basis for a new phylogenetic classification into four monophyletic genera: Helcion (four species; southern Africa), Cymbula (eight species; southern Africa, eastern Atlantic, southern Indian Ocean), Scutellastra (17 species; southern and southwestern Africa, Australia, Indo-West Pacific, Eastern Pacific) and Patella (nine species; northeastern Atlantic and Mediterranean). The analysis suggests sister-group relationships between Helcion and Cymbula, and between Scutellastra and Patella. In combination with present-day patterns of geographical distribution, this phylogenetic hypothesis is used to discuss the historical biogeography of the Patellidae. Scutellastra may have originated in southern Africa and dispersed across the Pacific, or alternatively may be a primitively Tethyan group. Both Helcion and Cymbula appear to have originated in southern Africa, but three Cymbula species have dispersed respectively to northwest Africa, St Helena and the southern Indian Ocean. The patellids of the northeastern Atlantic form a single clade, Patella (including P. pellucida), which may have arrived by northward dispersal of an ancestor from southern Africa, or possibly by vicariance of a widespread ancestral Tethyan distribution. The known fossil record of patellids is too fragmentary to permit choice between these alternatives.

Ridgway, S. A.

1998-01-01

310

Patellar instability.  

PubMed

Patella instability can cause significant pain and functional limitations. Several factors can predispose to patella instability, such as ligamentous laxity, increased anterior TT-TG distance, patella alta, and trochlear dysplasia. Acquired factors include MPFL injury or abnormal quadriceps function. In many cases, first-time dislocation can successfully be managed with physical therapy and other nonoperative management; however, more than one dislocation significantly increases the chance of recurrence. Surgical management can improve stability, but should be tailored to the injuries and anatomic risk factors for recurrent dislocation. Isolated lateral release is not supported by current literature and increases the risk of iatrogenic medial instability. Medial repair is usually reserved for patients with largely normal anatomy. MPFL reconstruction can successfully stabilize patients with medial soft tissue injury but is a technically demanding procedure with a high complication rate and risks of pain and arthrosis. Tibial tubercle osteotomy can address bony malalignment and also unload certain articular cartilage lesions while improving stability. Trochleoplasty may be indicated in individuals with a severely dysplastic trochlea that cannot otherwise be stabilized. A combination of procedures may be necessary to fully address the multiple factors involved in causing pain, loss of function, and risk of recurrence in patients with patellar instability. PMID:24993410

Koh, Jason L; Stewart, Cory

2014-07-01

311

MR imaging of patellar instability: injury patterns and assessment of risk factors.  

PubMed

First-time patellar dislocation typically occurs with twisting knee motions, during which the medial ligamentous stabilizers rupture, and the patella strikes against the lateral femoral condyle. The typical injury pattern is a tear of the medial patellofemoral ligament (MPFL) and bone bruises of the patella and the lateral femoral condyle. Additionally, complex injuries to bone, cartilage, and ligaments may occur. The ensuing loss of medial restraint favors future patellar dislocations, especially if additional risk factors are present. Recurrent patellar dislocations usually occur in individuals with anatomic variants of the patellar stabilizers, such as trochlear dysplasia, patella alta, and lateralization of the tibial tuberosity. Magnetic resonance (MR) imaging is reliable in identifying risk factors for chronic patellar instability and in assessing knee joint damage associated with patellar dislocation. MR imaging can thus provide important information for individually tailored treatment. Patients with primary patellar dislocation without severe internal derangement who lack major risk factors can be treated conservatively. Patients with pronounced ligamentous tears or large osteochondral lesions require prompt surgery. In addition, surgical correction of anatomic variants will help reduce the potential for chronic instability. The most common procedures, in addition to MPFL reconstruction, include trochleoplasty, medialization of the tibial tuberosity, and medial capsular plication. For comprehensive assessment of patellar dislocation, a radiologist should be able to identify typical injury patterns, know standard methods to assess risk factors for patellar instability, and be familiar with surgical options. PMID:20631363

Diederichs, Gerd; Issever, Ahi S; Scheffler, Sven

2010-01-01

312

A novel technique for reconstruction of the medial patellofemoral ligament in skeletally immature patients.  

PubMed

Habitual or recurrent dislocation of the patella in the skeletally immature patient is a particularly demanding problem since the etiology is frequently multifactorial. The surgical techniques successfully performed in adults with patellar instability may risk injury to an open growth plate if applied to children. We present a technique that preserves femoral and patellar insertion anatomy of medial patellofemoral ligament (MPFL) using a free semitendinosus autograft together with tenodesis to the adductor magnus tendon without damaging open physis on the patellar attachment of MPFL. A 3-cm long longitudinal skin incision is performed 10 mm distal to the tibial tuberosity on the anteromedial side. The semitendinosus tendon is harvested with the stripper. The semitendinosus tendon is placed on a preparation board and cleaned of muscle tissue. The usable part of the tendon should be at least 20 cm long and 4 mm wide. The two free ends of the graft are sutured with Krakow technique. A medial longitudinal incision 2 cm in length is made to expose the MPFL and to abrade the patellar attachment of vastus medialis obliquus. The first patellar tunnel is created with 4.5 mm drill at the mid aspect of the medial patella in the anteroposterior and proximal-distal direction. The drill hole is formed parallel to the articular surface of the center of the patella. The second tunnel is created with 3.2 mm drill and the entry point is localized at the center of the patella. These two tunnels intersect to form a single tunnel. The semitendinosus autograft is run through the bone tunnel in the patella. Double-stranded semitendinosus autograft is placed in the presynovial fatty plane between the second and the third layer of the medial retinaculum, and tenodesis to adductor magnus tendon is applied by a moderate medial force with the knee flexed at 30°. Aftercare includes immobilization of the joint limited to 30° flexion using an above-knee splint for 2 weeks. No recurrent dislocation was observed in three patients (4 knees) at a mean follow-up time of 17.7 months. Both range of motion and radiological finding were restored to normal limits. PMID:21479862

Yercan, Hüseyin S; Erkan, Serkan; Okcu, Güvenir; Ozalp, R Taçk?n

2011-08-01

313

Seasonality Records From Stable Isotopes and Trace Elements in Mussel and Limpet Shells From Archaeological Sites on Gibraltar  

NASA Astrophysics Data System (ADS)

Seasonal resolution climate records from mid and high latitudes would allow investigation of the role of seasonality in controlling mean climate on diverse timescales, and of the evolution of climate systems such as the North Atlantic Oscillation (NAO). But achieving such seasonal resolution is difficult for regions outside the growth range of surface corals. Marine mollusc shells provide a possible archive and contain growth increments varying in scale from tidal to annual. However, finding and dating sequences of marine mollusc shells spanning long periods of time is difficult due to sea-level change and the destructional nature of most coastal environments. In this study, we have made use of the habit of hominins on Gibraltar to collect molluscs for food over at least the last 120 kyr. In archaeological excavations of two caves (Gorham's and Vanguard Caves), mollusc shells were found, in habitation levels and in sediment blown into the caves. Existing 14C, OSL, and U-series chronologies provide a chronological framework for this suite of samples. The species found are predominantly Mytilus (mussels) or Patella (limpets). Gibraltar is an interesting location for paleoclimate reconstruction due to its proximity to the boundary of modern day climate belts but also due to its anthropological and archaeological importance. To gain a quantitative understanding of the local controls on stable isotopes and trace elements within Gibraltarian shells, we have initiated a water-sampling programme; emplaced a temperature and salinity logger near the sampling site; and marked live Patella and Mytilus with fluorescent dye to firmly establish growth rates and controls on chemical composition. We have also conducted stable-isotope and trace-element analysis of modern and fossil Patella and Mytilus shells by micromilling. Recent Patella and Mytilus shells show that the oxygen isotope composition of modern shells allow the accurate reconstruction of the full seasonal range in sea-surface temperature. Analysis of three fossil Mytilus samples contained within a Neanderthal occupation level from approximately 115 kyr show clear annual cycles in ? 18O but with different absolute values. Patella samples have also been analysed from the last glacial and from 800-300B.C. Results allow an assessment of past changes in seasonality and of the utility of this archeological shell material as an archive for past change.

Fa, D.; Ferguson, J. E.; Atkinson, T. C.; Barton, R. N.; Ditchfield, P.; Finlayson, G.; Finlayson, J. C.; Henderson, G. M.

2007-12-01

314

Dietary and environmental determinants of blood and bone lead levels in lactating postpartum women living in Mexico City.  

PubMed Central

Despite the recent declines in environmental lead exposure in the United States and Mexico, the potential for delayed toxicity from bone lead stores remains a significant public health concern. Some evidence indicates that mobilization of lead from bone may be markedly enhanced during the increased bone turnover of pregnancy and lactation, resulting in lead exposure to the fetus and the breast-fed infant. We conducted a cross-sectional investigation of the interrelationships between environmental, dietary, and lifestyle histories, blood lead levels, and bone lead levels among 98 recently postpartum women living in Mexico City. Lead levels in the patella (representing trabecular bone) and tibia (representing cortical bone) were measured by K X-ray fluorescence (KXRF). Multivariate linear regression models showed that significant predictors of higher blood lead included a history of preparing or storing food in lead-glazed ceramic ware, lower milk consumption, and higher levels of lead in patella bone. A 34 micrograms/g increase in patella lead (from the medians of the lowest to the highest quartiles) was associated with an increase in blood lead of 2.4 micrograms/dl. Given the measurement error associated with KXRF and the extrapolation of lead burden from a single bone site, this contribution probably represents an underestimate of the influence of trabecular bone on blood lead. Significant predictors of bone lead in multivariate models included years living in Mexico City, lower consumption of high calcium content foods, and nonuse of calcium supplements for the patella and years living in Mexico City, older age, and lower calcium intake for tibia bone. Low consumption of milk and cheese, as compared to the highest consumption category (every day), was associated with an increase in tibia bone lead of 9.7 micrograms Pb/g bone mineral. The findings of this cross-sectional study suggest that patella bone is a significant contributor to blood lead during lactation and that consumption of high calcium content foods may protect against the accumulation of lead in bone. Images Figure 1. Figure 1. Figure 2. Figure 2. PMID:8930549

Hernandez-Avila, M; Gonzalez-Cossio, T; Palazuelos, E; Romieu, I; Aro, A; Fishbein, E; Peterson, K E; Hu, H

1996-01-01

315

A Dominant-Negative Mutation of Mouse Lmx1b Causes Glaucoma and Is Semi-lethal via LBD1-Mediated Dimerisation  

PubMed Central

Mutations in the LIM-homeodomain transcription factor LMX1B cause nail-patella syndrome, an autosomal dominant pleiotrophic human disorder in which nail, patella and elbow dysplasia is associated with other skeletal abnormalities and variably nephropathy and glaucoma. It is thought to be a haploinsufficient disorder. Studies in the mouse have shown that during development Lmx1b controls limb dorsal-ventral patterning and is also required for kidney and eye development, midbrain-hindbrain boundary establishment and the specification of specific neuronal subtypes. Mice completely deficient for Lmx1b die at birth. In contrast to the situation in humans, heterozygous null mice do not have a mutant phenotype. Here we report a novel mouse mutant Icst, an N-ethyl-N-nitrosourea-induced missense substitution, V265D, in the homeodomain of LMX1B that abolishes DNA binding and thereby the ability to transactivate other genes. Although the homozygous phenotypic consequences of Icst and the null allele of Lmx1b are the same, heterozygous Icst elicits a phenotype whilst the null allele does not. Heterozygous Icst causes glaucomatous eye defects and is semi-lethal, probably due to kidney failure. We show that the null phenotype is rescued more effectively by an Lmx1b transgene than is Icst. Co-immunoprecipitation experiments show that both wild-type and Icst LMX1B are found in complexes with LIM domain binding protein 1 (LDB1), resulting in lower levels of functional LMX1B in Icst heterozygotes than null heterozygotes. We conclude that Icst is a dominant-negative allele of Lmx1b. These findings indicate a reassessment of whether nail-patella syndrome is always haploinsufficient. Furthermore, Icst is a rare example of a model of human glaucoma caused by mutation of the same gene in humans and mice. PMID:24809698

Cross, Sally H.; Macalinao, Danilo G.; McKie, Lisa; Rose, Lorraine; Kearney, Alison L.; Rainger, Joe; Thaung, Caroline; Keighren, Margaret; Jadeja, Shalini; West, Katrine; Kneeland, Stephen C.; Smith, Richard S.; Howell, Gareth R.; Young, Fiona; Robertson, Morag; van t' Hof, Rob; John, Simon W. M.; Jackson, Ian J.

2014-01-01

316

Tensile properties of the medial patellofemoral ligament: The effect of specimen orientation  

PubMed Central

For recurrent patellar dislocation, reconstruction of the medial patellofemoral ligament (MPFL) with replacement autografts has often been performed but with only little data on the tensile properties of the MPFL to guide graft selection. With its complex anatomy and geometry, these properties are difficult to obtain. In this study, we showed how the orientation of the femur-MPFL-patella complex (FMPC) during uniaxial tensile testing can have a significant effect on its structural properties. Twenty two FMPCs were isolated from porcine stifle joints and randomly assigned to two groups of 11 each. For the first group, the specimens were loaded to failure with the patella oriented 30 degrees away from the direction of the applied load to mimic its orientation in situ, called natural orientation. In the second group, the patella was aligned in the direction of the tensile load, called non-natural orientation. The stiffness for the natural orientation group was 65 ± 13 N/mm, 32% higher than that for the non-natural orientation group (50 ± 17 N/mm; p < 0.05). The ultimate loads were 438 ± 128 N and 386 ± 136 N, respectively (p > 0.05). Ten out of 11 specimens in the natural orientation group failed at the femoral attachment (the narrowest portion of the MPFL) compared to 6 out of 11 in the non-natural orientation group. Our findings suggest that the specimen orientation that mimics the in-situ loading conditions of the MPFL should be used to obtain more representative data for the structural properties of the FMPC. PMID:24332616

Kim, Kwang E.; Hsu, Shan-Ling; Woo, Savio L-Y.

2014-01-01

317

Computational wear simulation of patellofemoral articular cartilage during in vitro testing.  

PubMed

Though changes in normal joint motions and loads (e.g., following anterior cruciate ligament injury) contribute to the development of knee osteoarthritis, the precise mechanism by which these changes induce osteoarthritis remains unknown. As a first step toward identifying this mechanism, this study evaluates computational wear simulations of a patellofemoral joint specimen wear tested on a knee simulator machine. A multibody dynamic model of the specimen mounted in the simulator machine was constructed in commercial computer-aided engineering software. A custom elastic foundation contact model was used to calculate contact pressures and wear on the femoral and patellar articular surfaces using geometry created from laser scan and MR data. Two different wear simulation approaches were investigated--one that wore the surface geometries gradually over a sequence of 10 one-cycle dynamic simulations (termed the "progressive" approach), and one that wore the surface geometries abruptly using results from a single one-cycle dynamic simulation (termed the "non-progressive" approach). The progressive approach with laser scan geometry reproduced the experimentally measured wear depths and areas for both the femur and patella. The less costly non-progressive approach predicted deeper wear depths, especially on the patella, but had little influence on predicted wear areas. Use of MR data for creating the articular and subchondral bone geometry altered wear depth and area predictions by at most 13%. These results suggest that MR-derived geometry may be sufficient for simulating articular cartilage wear in vivo and that a progressive simulation approach may be needed for the patella and tibia since both remain in continuous contact with the femur. PMID:21453922

Li, Lingmin; Patil, Shantanu; Steklov, Nick; Bae, Won; Temple-Wong, Michele; D'Lima, Darryl D; Sah, Robert L; Fregly, Benjamin J

2011-05-17

318

Trace element levels in mollusks from clean and polluted coastal marine sites in the Mediterranean, Red and North Seas  

NASA Astrophysics Data System (ADS)

The trace element contamination levels in mollusks were evaluated for different marine coastal sites in the Mediterranean (Israeli coast), Red (Israeli coast) and North (German coast) Seas. Three bivalve species (Mactra corallina, Donax sp, and Mytilusedulis) and two gastropod species (Patella sp.and Cellana rota) were sampled at polluted and relatively clean sites, and their soft tissue analyzed for Hg, Cd, Zn, Cu, Mn and Fe concentrations. Representative samples were screened for organic contaminants [(DDE), polychlorinated biphenyls PCBs and polycyclic aromatic hydrocarbons (PAHs)] which exhibited very low concentrations at all sites. In the Red Sea, the gastropod C. rota showed low levels of Hg (below detection limit) and similar Cd concentrations at all the examined sites, while other trace elements (Cu, Zn, Mn, Fe) were slightly enriched at the northern beach stations. Along the Mediterranean coast of Israel, Hg and Zn were enriched in two bivalves (M. corallina and Donax sp.) from Haifa Bay, both species undergoing a long-term decrease in Hg based on previous studies. Significant Cd and Zn enrichment was detected in Patella sp. from the Kishon River estuary at the southern part of Haifa Bay. In general, Patella sp. and Donax sp. specimens from Haifa Bay exhibited higher levels of Cd compared to other sites along the Israeli Mediterranean coast, attributed to the enrichment of Cd in suspended particulate matter. Along the German coast (North Sea) M. edulis exhibited higher concentrations of Hg and Cd at the Elbe and Eider estuaries, but with levels below those found in polluted sites elsewhere.

Herut, Barak; Kress, Nurit; Shefer, Edna; Hornung, Hava

319

The very surface states on GaAs(001) surface by means of electronic and optical techniques  

NASA Astrophysics Data System (ADS)

Until now, Reflectance-Anisotropy Spectroscopy (RAS) in the visible has been the most used technique to quantify the anisotropy of these surfaces [1]. Low-energy electrons are believed to perturb more than photons and have not been employed to this purpose, despite their shorter penetration depth. In our presentation we show experimental results of High-Resolution Electron-Energy-Loss Spectroscopy (HREELS) applied to investigate the anisotropy of the GaAs(001)-c(4x4) and beta2(2x4) surfaces. We demonstrate the higher surface sensitivity of HREELS compared to RAS. Measurements are performed on high-quality samples grown in situ by Molecular Beam Epitaxy (MBE). The loss spectra taken in the two orthogonal surface directions have different intensities, particularly close to the fundamental gap, where surface like resonances, involving dimers, are observed. We discuss our HREELS and RAS data to identify the source of the anisotropy close to the critical point transitions where surface and bulk like excitations coexist. Our data are in very good agreement with DFT-LDA calculations for loss energies up to 3.5 eV [2]. The exposure of the reconstructed surfaces to molecular oxygen affects strongly the spectral features. [1] D.E.Aspnes, J.P.Harbison, A.A.Studna, L.T.Florez, Phys. Rev. Lett. 59 (1987) 1687; I.Kamiya, D.E.Aspnes, L.T.Florez, and J.T.Harbison, Phys. Rev. B 46 (1992) 15894. [2] A.Balzarotti, F.Arciprete, M.Fanfoni, F.Patella, E. Placidi, G.Onida, R.Del Sole, Surf. Sci. Lett. 524, L71 (2003); A.Balzarotti, E.Placidi, F.Arciprete, M.Fanfoni, F.Patella, Physical Review B, 67 115332 (2003); F.Arciprete, C. Goletti, E. Placidi, M.Fanfoni, F.Patella, P. Chiaradia, C. Hogan and A. Balzarotti, Phys. Rev. B 68 125328 (2003).

Placidi, Ernesto

2004-03-01

320

Detection of changes in articular cartilage proteoglycan by T1? magnetic resonance imaging  

PubMed Central

The purpose of this work is to demonstrate the feasibility of T1?-weighted magnetic resonance imaging (MRI) to quantitatively measure changes in proteoglycan content in cartilage. The T1? MRI technique was implemented in an in vivo porcine animal model with rapidly induced cytokine-mediated cartilage degeneration. Six pigs were given an intra-articular injection of recombinant porcine interleukin-1? (IL-1?) into the knee joint before imaging to induce changes in cartilage via matrix metalloproteinase (MMP) induction. The induction of MMPs by IL-1 was used since it has been extensively studied in many systems and is known to create conditions that mimic in part characteristics similar to those of osteoarthritis. The contralateral knee joint was given a saline injection to serve as an internal control. T1?-weighted MRI was performed on a 4 T whole-body clinical scanner employing a 2D fast spin-echo-based T1? imaging sequence. T1? relaxation parameter maps were computed from the T1?-weighted image series. The average T1? relaxation rate, R1? (1/T1?) of the IL-1?-treated patellae was measured to be on average 25% lower than that of saline- injected patellae indicating a loss of proteoglycan. There was an average reduction of 49% in fixed charge density, measured via sodium MRI, of the IL-1?-treated patellae relative to control corroborating the loss of proteoglycan. The effects of IL-1?, primarily loss of PG, were confirmed by histological and immunochemical findings. The results from this study demonstrate that R1? is able to track proteoglycan content in vivo. PMID:15607881

Wheaton, Andrew J.; Dodge, George R.; Borthakur, Arijitt; Kneeland, J. Bruce; Schumacher, H. Ralph; Reddy, Ravinder

2010-01-01

321

Patellar Cartilage: T2 Values and Morphologic Abnormalities at 3.0-T MR Imaging in Relation to Physical Activity in Asymptomatic Subjects from the Osteoarthritis Initiative1  

PubMed Central

Purpose: To study the interrelationship between patella cartilage T2 relaxation time, other knee abnormalities, and physical activity levels in asymptomatic subjects from the Osteoarthritis Initiative (OAI) incidence cohort. Materials and Methods: The study had institutional review board approval and was HIPAA compliant. One hundred twenty subjects from the OAI without knee pain (age, 45–55 years) and with risk factors for knee osteoarthritis (OA) were studied by using knee radiographs, 3.0-T knee magnetic resonance (MR) images (including intermediate-weighted fast spin-echo and T2 mapping sequences), and the Physical Activity Scale for the Elderly. MR images of the right knee were assessed by two musculoskeletal radiologists for the presence and grade of abnormalities. Segmentation of the patella cartilage was performed, and T2 maps were generated. Statistical significance was determined by using analysis of variance, ?2 analysis, correlation coefficient tests, the Cohen ?, and a multiple linear regression model. Results: Cartilage lesions were found in 95 (79.0%) of 120 knees, and meniscal lesions were found in 54 (45%) of 120 knees. A significant correlation between patella cartilage T2 values and the severity and grade of cartilage (P = .0025) and meniscus (P = .0067) lesions was demonstrated. Subjects with high activity levels had significantly higher prevalence and grade of abnormalities and higher T2 values (48.7 msec ±4.35 vs 45.8 msec ±3.93; P < .001) than did subjects with low activity levels. Conclusion: Middle-aged asymptomatic individuals with risk factors for knee OA had a high prevalence of cartilage and meniscus knee lesions. Physically active individuals had more knee abnormalities and higher patellar T2 values. Additional studies will be needed to determine causality. © RSNA, 2010 PMID:20019141

Liebl, Hans; Krug, Roland; Lane, Nancy E.; Nevitt, Michael C.; Lynch, John; McCulloch, Charles E.; Link, Thomas M.

2010-01-01

322

A dominant-negative mutation of mouse Lmx1b causes glaucoma and is semi-lethal via LBD1-mediated dimerisation.  

PubMed

Mutations in the LIM-homeodomain transcription factor LMX1B cause nail-patella syndrome, an autosomal dominant pleiotrophic human disorder in which nail, patella and elbow dysplasia is associated with other skeletal abnormalities and variably nephropathy and glaucoma. It is thought to be a haploinsufficient disorder. Studies in the mouse have shown that during development Lmx1b controls limb dorsal-ventral patterning and is also required for kidney and eye development, midbrain-hindbrain boundary establishment and the specification of specific neuronal subtypes. Mice completely deficient for Lmx1b die at birth. In contrast to the situation in humans, heterozygous null mice do not have a mutant phenotype. Here we report a novel mouse mutant Icst, an N-ethyl-N-nitrosourea-induced missense substitution, V265D, in the homeodomain of LMX1B that abolishes DNA binding and thereby the ability to transactivate other genes. Although the homozygous phenotypic consequences of Icst and the null allele of Lmx1b are the same, heterozygous Icst elicits a phenotype whilst the null allele does not. Heterozygous Icst causes glaucomatous eye defects and is semi-lethal, probably due to kidney failure. We show that the null phenotype is rescued more effectively by an Lmx1b transgene than is Icst. Co-immunoprecipitation experiments show that both wild-type and Icst LMX1B are found in complexes with LIM domain binding protein 1 (LDB1), resulting in lower levels of functional LMX1B in Icst heterozygotes than null heterozygotes. We conclude that Icst is a dominant-negative allele of Lmx1b. These findings indicate a reassessment of whether nail-patella syndrome is always haploinsufficient. Furthermore, Icst is a rare example of a model of human glaucoma caused by mutation of the same gene in humans and mice. PMID:24809698

Cross, Sally H; Macalinao, Danilo G; McKie, Lisa; Rose, Lorraine; Kearney, Alison L; Rainger, Joe; Thaung, Caroline; Keighren, Margaret; Jadeja, Shalini; West, Katrine; Kneeland, Stephen C; Smith, Richard S; Howell, Gareth R; Young, Fiona; Robertson, Morag; van T' Hof, Rob; John, Simon W M; Jackson, Ian J

2014-05-01

323

Biomechanical comparison of extensile exposures in total knee arthroplasty.  

PubMed

The "banana peel" exposure is a novel technique for knee joint exposure that consists of partially peeling the patellar tendon off the tibia, leaving the extensor mechanism intact distally and laterally. Although good clinical results have been reported with this technique with no disruption of the extensor mechanism, concerns exist that it could cause extensor lag, quadriceps weakness, or patellar tendon rupture. We compared the banana peel exposure repair to tibial tubercle osteotomy repair, which we chose as our benchmark procedure because much is known about its associated healing and rehabilitation protocols. In our study of 16 paired, fresh-frozen human knee specimens, the 2 techniques were used alternately for the right and left knees. To measure acute strength, 10 pairs were tested. The patella was clamped and pulled superiorly at 25 mm/min until failure. For cyclical testing (6 pairs), the knee was extended from 90 degrees of flexion to 0 degrees for 2000 cycles at 0.25 Hz while we monitored the distance between the inferior pole of the patella and the tibial diaphysis using a passive optical kinematic measuring system. Mean failure strengths of the banana peel and osteotomy groups were 2642+/-1104 N and 2123+/-562 N, respectively, suggesting that the banana peel repair is not weaker than the osteotomy repair. Neither group had a significant increase (via paired Student t test, P>.05) in the distance between the inferior pole of the patella and the tibial diaphysis, suggesting that neither exposure would result in extensor lag. PMID:20806776

Wall, Simon J; Rose, David M; Khanuja, Harpal S; Sutter, Edward G; Knight, Trevor A; Belkoff, Stephen M; Mears, Simon C

2010-06-01

324

Taping for knee osteoarthritis.  

PubMed

Taping can be used to reduce pain in knee osteoarthritis. There are different methods of taping, but the common effect is to exert a medially directed force on the patella to increase the patellofemoral contact area, thereby decreasing joint stress and reducing pain. Taping can be performed by a physiotherapist, but self taping can be taught, which enhances self management. Taping for knee osteoarthritis has National Health and Medical Research Council (NHMRC) Level I evidence of efficacy for pain relief and is associated with negligible adverse effects that generally include minor skin irritation. PMID:24130976

2013-10-01

325

Inhibition of the spider heartbeat by gravity and vibration  

NASA Technical Reports Server (NTRS)

The rate and vigor of the spider heartbeat is controlled by an external pacemaker. A mechanical feature of the spider cardio-vascular system is the production of high serum pressure in the prosoma and the legs. This appears to be the source for leg extension. The lyriform organ on the patella of the leg is sensitive to vibratory and kinesthetic stimuli. This sensitivity depends upon the degree of leg extension. Thus the activity of the heart and the response characteristics of the sense receptor are related. The effect of a supra-threshold vibratory or gravitational stimulus is to produce an inhibition and a tachycardia of the spider heartbeat.

Finck, A.

1984-01-01

326

Musculoskeletal injuries in adolescents.  

PubMed

This article reviews the anatomy of the physis and the most common classification of injuries or fractures through the physis. The common apophyseal injuries of Osgood-Schlatter, Severs disease and iliac apophysitis, are reviewed in addition to a review of the most common osteochondritides, including Panner's disease and Osteochondritis Dessicans of the femur and talus. An understanding of these is key to diagnosis and treatment of adolescent musculoskeletal injuries. This article also reviews slipped capital femoral epiphysis, little leaguer's elbow, anterior cruciate and collateral ligament injuries, patella problems, ankle sprains and several common fractures in children. PMID:9469924

Kaeding, C C; Whitehead, R

1998-03-01

327

Intracellular coagulation inhibits the extraction of proteins from Prochloron  

NASA Technical Reports Server (NTRS)

Protein extraction from the prokaryotic alga Prochloron LP (isolated from the ascidian host Lissoclinum patella) was complicated by an irreversible loss of cell fragility in the isolated algae. Accompanying this phenomenon, which is termed intracellular coagulation, was a redistribution of thylakoids around the cell periphery, a loss of photosynthetic O2 production, and a drastic decrease in the extractability of cell proteins. Procedures are described for the successful preparation and transport of cell extracts yielding the enzymes glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase as well as other soluble proteins.

Fall, R.; Lewin, R. A.; Fall, L. R.

1983-01-01

328

Malalignment and cartilage lesions in the patellofemoral joint treated with autologous chondrocyte implantation  

Microsoft Academic Search

Purpose  The aim of our current study is to present the 12.6 years’ follow-up results in patients with cartilage lesions of the patellofemoral\\u000a joint, treated with autologous chondrocyte implantation (ACI) with the use of periosteum.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Ninety-two patients having patella or trochlea lesion participated in this study. Lysholm and Tegner questionnaires were completed\\u000a 12.6 years (SD 2.3 years) after the surgery. The patients were asked

Haris S. Vasiliadis; Anders Lindahl; Anastasios D. Georgoulis; Lars Peterson

2011-01-01

329

Contrary view: wear is not an issue.  

PubMed

Wear was not an issue with total knee replacements that had a round-on-round design such as the Total Condylar and the Insall-Burstein prostheses. As long as designs do not try to reproduce normality in kinematics, wear will not be an issue. To date, there are no data that mobile-bearing knee replacements will decrease wear complications as compared with round-on-round fixed designs. Wear is not an issue if the total knee replacement is done with a round-on-round design with a cobalt chrome femoral component, monoblock tibial component, and an all-polyethylene patella, all with cemented fixation. PMID:12439244

Dorr, Lawrence D

2002-11-01

330

Diurnal rhythm in the cell-division frequency of prochloron (prochlorophyta) in nature  

NASA Technical Reports Server (NTRS)

Frequencies of cell division stages in suspensions of Prochloron cells, expressed at regular intervals throughout a natural day-night cycle from several colonies of four species of host didemnid, are given. The proportion of dividing cells of Prochloron living symbiotically in colonies of a didemnid, Diplosoma virens, rises from about 4% during the night (20.00-04.00 hrs.) to about 13% in the morning (0,.00-12.00 hrs.), and then falls again in the afternoon. Similiar, though less pronounced, changes were observed among Prochloron cells in two other symbiotic didemnids, Lissoclinum patella and L. voeltzkowi.

Lewin, R. A.; Cheng, L.; Matta, J.

1983-01-01

331

Lead Exposure and Fear-Potentiated Startle in the VA Normative Aging Study: A Pilot Study of a Novel Physiological Approach to Investigating Neurotoxicant Effects  

PubMed Central

Background Physiologically-based indicators of neural plasticity in humans could provide mechanistic insights into toxicant actions on learning in the brain, and perhaps prove more objective and sensitive measures of such effects than other methods. Objectives We explored the association between lead exposure and classical conditioning of the acoustic startle reflex (ASR)—a simple form of associative learning in the brain—in a population of elderly men. Fifty-one men from the VA Normative Aging Study with cumulative bone lead exposure measurements made with K-X-Ray-Fluorescence participated in a fear-conditioning protocol. Results The mean age of the men was 75.5 years (standard deviation [sd]=5.9) and mean patella lead concentration was 22.7?g/g bone (sd=15.9). Baseline ASR eyeblink response decreased with age, but was not associated with subsequent conditioning. Among 37 men with valid responses at the end of the protocol, higher patella lead was associated with decreased awareness of the conditioning contingency (declarative learning; adjusted odds ratio [OR] per 20 ?g/g patella lead=0.91, 95% confidence interval [CI]: 0.84, 0.99, p=0.03). Eyeblink conditioning (non-declarative learning) was 0.44sd less (95% CI:?0.91, 0.02; p=0.06) per 20 ?g/g patella lead after adjustment. Each result was stronger when correcting for the interval between lead measurement and startle testing (awareness: OR=0.88, 95% CI: 0.78, 0.99, p = 0.04; conditioning: ?0.79sd less, 95% CI: ?1.56, 0.03, p = 0.04). Conclusions This initial exploration suggests that lead exposure interferes with specific neural mechanisms of learning and offers the possibility that the ASR may provide a new approach to physiologically explore the effects of neurotoxicant exposures on neural mechanisms of learning in humans with a paradigm that is directly comparable to animal models. PMID:23603705

Grashow, Rachel; Miller, Mark W.; McKinney, Ann; Nie, Linda H.; Sparrow, David; Hu, Howard; Weisskopf, Marc G.

2013-01-01

332

Lateral Patellofemoral Ligament Reconstruction Using a Quadriceps Tendon Graft  

PubMed Central

Medial patellar subluxation (MPS) is normally described after a lateral retinacular release. However, isolated MPS in the absence of a previous lateral release does occur. This type of patellar instability is often overlooked, and a high index of suspicion is needed for appropriate diagnosis and treatment. This report describes a technique developed in response to episodes of isolated MPS. The technique uses a partial-thickness graft from the quadriceps tendon to reconstruct the lateral patellofemoral ligament and provide stability to the lateral side of the patella.

Saper, Michael G.; Shneider, David A.

2014-01-01

333

An analytical model to predict interstitial lubrication of cartilage in migrating contact areas.  

PubMed

For nearly a century, articular cartilage has been known for its exceptional tribological properties. For nearly as long, there have been research efforts to elucidate the responsible mechanisms for application toward biomimetic bearing applications. It is now widely accepted that interstitial fluid pressurization is the primary mechanism responsible for the unusual lubrication and load bearing properties of cartilage. Although the biomechanics community has developed elegant mathematical theories describing the coupling of solid and fluid (biphasic) mechanics and its role in interstitial lubrication, quantitative gaps in our understanding of cartilage tribology have inhibited our ability to predict how tribological conditions and material properties impact tissue function. This paper presents an analytical model of the interstitial lubrication of biphasic materials under migrating contact conditions. Although finite element and other numerical models of cartilage mechanics exist, they typically neglect the important role of the collagen network and are limited to a specific set of input conditions, which limits general applicability. The simplified approach taken in this work aims to capture the broader underlying physics as a starting point for further model development. In agreement with existing literature, the model indicates that a large Peclet number, Pe, is necessary for effective interstitial lubrication. It also predicts that the tensile modulus must be large relative to the compressive modulus. This explains why hydrogels and other biphasic materials do not provide significant interstitial pressure under high Pe conditions. The model quantitatively agrees with in-situ measurements of interstitial load support and the results have interesting implications for tissue engineering and osteoarthritis problems. This paper suggests that a low tensile modulus (from chondromalacia or local collagen rupture after impact, for example) may disrupt interstitial pressurization, increase shear stresses, and activate a condition of progressive surface damage as a potential precursor of osteoarthritis. PMID:24275436

Moore, A C; Burris, D L

2014-01-01

334

Long-term impacts of human harvesting on shellfish: North Iberian top shells and limpets from the Upper Palaeolithic to the present  

NASA Astrophysics Data System (ADS)

Humans have contributed to phenotypic and demographic changes in their prey from very early on in the colonization of Europe, including the harvesting of shellfish in coastal ecosystems. We estimated trends in population growth (variation in the number of individuals) from DNA sequences of modern specimens in two North Iberian molluscs, top shells (Osilinus lineatus, from 24 sequences and 14 haplotypes) and limpets (Patella vulgata, taken from the bibliography), which were subjected to very different levels of harvesting pressure during the Upper Palaeolithic (~ 20000 to ~ 6000 years ago). The less harvested Osilinus top shells experienced fluctuations in population numbers coincident with climatic oscillations. Patella limpets, which were harvested in greater numbers, suffered clear and uninterrupted decreases in their numbers during the Upper Palaeolithic. These trends coincided with morphological changes in shell size (length or width) in the same direction (i.e., shell size decreased when population size decreased and vice versa). The differing trends seen in taxa subjected to different intensities of harvesting pressure suggest that climate effects were overcome by anthropogenic selection (leading to a smaller average length) in limpets. We suggest that intense fishing pressure may have induced irreversible shell length decreases in the most exploited species.

Turrero, Pablo; Muñoz-Colmenero, A. Marta; Prado, Andrea; Garcia-Vazquez, Eva

2014-11-01

335

Evaluating factors affecting patellar component fixation strength in total knee arthroplasty.  

PubMed

Complications related to the patellofemoral joint after total knee arthroplasty (TKA) represent up to 50% of TKA reoperations. Shear forces across the knee produce wear and occasionally result in failure of fixation of all-polyethylene patellar components. We conducted a study to evaluate the effect of 2 factors on the shear strength of patellar component fixation: time between cement mixing and application of the patellar component, and amount of pressure applied during implantation. Fifty-four patellae were harvested from 27 cadavers and were prepared as for a TKA, allowing 3 different amounts of time for the cement to set or cure before application, and using 3 different pressures. The patellae were mounted and tested for fixation strength with a materials testing machine. Fixation was significantly stronger (P = .006) at 42 pounds of pressure after curing the cement for 8 minutes (compared with 2 minutes) and was significantly stronger (P = .005) after 2 minutes of curing at 42 pounds of pressure (compared with 62 pounds of pressure). We concluded that allowing the cement to cure while cementing the femoral and tibial components does not jeopardize fixation of the patellar component and that excessive compression of a patellar clamp may weaken fixation. PMID:24078966

Wagner, Russell A; Lesley, Nathan E; Coté, René E; Tayag, Tristan J

2013-09-01

336

A new isometric quadriceps-strengthening exercise using EMG-biofeedback  

PubMed Central

A new isometric contraction quadriceps-strengthening exercise was developed to restore the quadriceps strength lost after knee surgery more rapidly. This study evaluated the results of this new method. Patients were taught to perform the isometric quadriceps-strengthening exercise in the unaffected knee in the supine position, and then they performed it in the affected knee. First, patients were taught the classical isometric quadriceps-strengthening exercise, and then they were taught our new alternative method: “pull the patella superiorly tightly and hold the leg in the same position for 10 seconds”. Afterward, the quadriceps contraction was evaluated using a non-invasive Myomed 932 EMG-biofeedback device (Enraf-Nonius, The Netherlands) with gel-containing 48 mm electrodes (Türklab, The Turkey) placed on both knees. The isometric quadriceps-strengthening exercise performed using our new method had stronger contraction than the classical method (P < 0.01). The new method involving pulling the patella superiorly appears to be a better choice, which can be applied easily, leading to better patient compliance and greater quadriceps force after arthroscopic and other knee surgeries. PMID:25356122

Kesemenli, Cumhur C; Sarman, Hakan; Baran, Tuncay; Memisoglu, Kaya; Binbir, Ismail; Savas, Yilmaz; Isik, Cengiz; Boyraz, Ismail; Koc, Bunyamin

2014-01-01

337

Photoadaptation and protection against active forms of oxygen in the symbiotic procaryote Prochloron sp. and its ascidian host  

SciTech Connect

Superoxide dismutase, ascorbate, peroxidase, and catalase activities were studied in the symbiotic photosynthetic procaryote Prochloron sp. and its ascidian host Lissoclinum patella. The protein-specific activities of these antioxidant enzymes in the Prochloron sp. and L. patella collected at different depths from the Great Barrier Reef, Australia, were directly proportional to irradiance, whereas the pigment concentrations in the Prochloron sp. were inversely proportional to irradiance. The presence of a cyanide-sensitive superoxide dismutase, presumably a Cu-An metalloprotein, in the Prochloron sp. extends the possible phylogenetic distribution of this protein. The concentration of UV-absorbing mycosporine-like amino acids in inversely proportional to irradiance in both the host and symbiont, suggesting that these compounds may not provide sufficient protection against UV radiation in high-irradiance environments. The significant differences in the specific activities of these antioxidant enzymes, cellular photosynthetic pigment concentrations, and UV-absorbing compounds from high- and low-irradiance habitats constitute an adaptive response to different photic environments. These photoadaptive responses are essential to prevent inhibition of photosynthesis by high fluxes of visible and UV radiation.

Lesser, M.P.; Stochaj, W.R. (Univ. of Maine, Orono (USA))

1990-06-01

338

Dual tunnel medial patellofemoral ligament reconstruction for patients with patellar dislocation using a semitendinosus tendon autograft.  

PubMed

The purpose of this study was to describe a safer and more anatomical technique of MPFL reconstruction and to report the short-term results. The subjects included 20 patients with patellar dislocation with a mean age of 23. The operation was performed using a double-looped autogenous semitendinosus tendon graft. Two small bone tunnels were made at the medial edge of the patella, mimicking the wide patellar insertion of the MPFL and a bone tunnel was made at the femoral insertion site. The free ends of the graft attached to the patella and the loop end was fixed to the femoral side. Five patients were available for follow-up interviews by telephone and the remaining 15 were directly examined by physical examination and radiographic evaluation at 2 years or longer postoperatively. The average follow-up period was 30 months. Re-dislocation or patellar fracture was not seen in any patients. The average Kujala's score was 96 with a range from 84 to 100. Six patients were classified as excellent and 14 as good, according to the Crosby and Insall grading system. Radiographically, narrowing of the patellofemoral joint space was observed in 2 cases with previous osteochondral fracture out of those who were directly examined. The dual tunnel MPFL reconstruction produces favorable results in subjective and functional assessment of outcome without complications. PMID:20684880

Toritsuka, Yukiyoshi; Amano, Hiroshi; Mae, Tatsuo; Uchida, Ryohei; Hamada, Masayuki; Ohzono, Kenji; Shino, Konsei

2011-08-01

339

[Axial correction in knee revision arthroplasty].  

PubMed

Implant malalignment is a major cause for early loosening, increased wear, painful limitation of motion, and patient dissatisfaction in total knee arthroplasty. Validated diagnostic algorithms and a deeper understanding of the pathological mechanisms underlying functional deficits and pain resulting from malalignment explain the increasing number of revision operations on unloosened prostheses, which are now nearly as common as revisions for implant loosening. Common reasons are component malpositioning are a shifted joint line, or a non-physiological patella position. The success of any revision procedure basically depends on: (1) correct component positioning, (2) equal and symmetrical flexion and extension gaps, (3) restoration of joint line, and (4) a physiological patella height. The adequate grade of implant constraint has to be determined intra-operatively. A higher loosening rate of constrained implants as well as increased wear and painful limitation of motion in case of instability have to be taken into account. In the present work, a diagnostic and therapeutic algorithm for malalignment of knee prostheses is presented. PMID:16362140

Perka, C; Tohtz, S; Matziolis, G

2006-02-01

340

[Iatrogenic "metalloma" (titanoma) caused by implant failure in "metal-backed" patellar joint surface replacement].  

PubMed

Patellofemoral problems frequently provide the cause for revisions after total knee replacements (TKR). Problems with metal-backed patellae, in particular, have been reported on in the past, with a failure rate of 33%. As a result of implant failure, there is an increase of polyethylene and metallic wear, which eventually leads to a synovialitis and metallosis. We report a case of a iatrogenic induced metallosis of the knee joint resulting from failure of a metal-backed patella component with the formation of a substantial pseudotumor within the popliteal fossa. Intraoperatively, a browny-grey, knotted and hard structure was to be seen, which histologically imposed as a hyalinated scar tissue with black particular deposits. Energy dispersive X-ray microanalysis showed a high level of titanium within the intra- and extracellular deposits. In differential diagnosis these findings were postulated as "metalloma" (titanoma). In cases of periprosthetic pseudotumors, particular those with implant failure, a iatrogenic-induced metalloma should be considered. PMID:11995225

Büttner-Janz, Karin; Müller, M; Müller, K M; Friemann, J

2002-03-01

341

Assessment of the damage in retrieved patellar components.  

PubMed

Patellofemoral complications are cited as a leading cause for revision surgery following total knee arthroplasty. Despite widespread clinical use, the decision to resurface the patella, or not, is controversial and remains surgeon dependent. Damage to the patellar component can lead to revision surgery; however, little work exists investigating the damage they sustain in vivo. Twenty-four retrieved patellar components were assessed for damage. There was a wide variation in wear scar morphology, although the mean wear scar area spanned mediolaterally in a band across the articular surface and was 364.32±64.7 mm2 in area. Maximum linear penetration was located in the lateral region of the articular surface. Assessment of damage mode grading indicated that it was more severe in the lateral quadrant, although the method's lack of consideration of the chronological progression of wear creates uncertainty over this finding. Volume change ranged from ?1.3 to ?45.16 mm3/year, and maximum penetration was in the lateral region. Damage to the patellar component of knee replacement has been shown to be significant. The number of components in the study was too small to determine a difference in damage in all-polyethylene and metal-backed designs; however, the volume loss of all-polyethylene patellae was found to be significant. PMID:21284589

Ellison, Peter; Fisher, John

2010-01-01

342

Mechanical and morphological evaluation of osteochondral implants in dogs.  

PubMed

The mechanical behavior of osteochondral defects was evaluated in this study with the intention of developing alternative procedures. Cylindrical pins (5.00 mm in diameter and in height) made of pHEMA hydrogel covered ultra-high molecular weight polyethylene (UHMWPE) or beta-tricalcium phosphate (beta-TCP) matrix were used. Ostoechondral defects were caused in the knees of adult dogs and the evaluation was carried out after a 9-month follow-up period. The mechanical behavior of the implants was evaluated by means of an indentation creep test that showed that the UHMWPE matrix maintained its viscoelastic behavior even after follow-up time, while the beta-TCP matrix osteochondral implants presented significant alterations. It is believed that the beta-TCP osteochondral implants were unable to withstand the load applied, causing an increase of complacency when compared to the UHMWPE osteochondral implants. Based on micro and macroscopic analysis, no significant wear was observed in either of the osteochondral implants when compared to the controls. However, morphological alterations, with fragmentation indices in the patella, were observed either due to friction with the hydrogel in the first postoperative months or due to forming of a dense conjunctive tissue. This wear mechanism caused on the counterface of the implant (patella) was observed, notwithstanding the osteochondral implant studied. PMID:18370946

Bavaresco, Vanessa P; Garrido, Luiz; Batista, Nilza A; Malmonge, Sônia M; Belangero, William D

2008-04-01

343

Custom rotating-hinge total knee replacement in patients with spina bifida and severe neuromuscular dysfunction.  

PubMed

Spina bifida (SB) is a congenital disorder which may result in a number of musculoskeletal problems. Total knee replacement (TKR) in this patient group is technically demanding due to bone deformity, soft tissue contracture, muscle tone abnormality and ligament insufficiency. This is a retrospective review of three patients with SB and disabling knee arthritis who were managed with a custom rotating-hinge (RHK) total knee system. All patients reported an improvement in knee pain and stability at mean follow-up 47 months (43-53). Mean Oxford Knee score improved from 21 preoperatively to 32 at final follow-up. One patient required revision of tibial and patella components at 37 months for lateral patella instability and excessive wear. Custom RHK for patients with SB, severe neuromuscular dysfunction and bone deformity relieves pain, restores stability and improves early knee function; however there is a significant risk of extensor mechanism complications and functional outcome is worse than primary TKR in the general population. PMID:22718075

Sewell, M D; Al-Hadithy, N; Hanna, S A; Al-Khateeb, H; Carrington, R W J; Blunn, G W; Skinner, J A; Briggs, T W R

2012-09-01

344

Amino acid geochronology of raised beaches in south west Britain  

NASA Astrophysics Data System (ADS)

Based on (1) the epimerization of L:isoleucine to D:alloisoleucine ( {D}/{L} ratios) in Patella vulgata, Littorina littorea, L. littoralis, L. saxatilis, Littorina species and Nucella lapillus from raised beaches in south west Britain, (2) statistical analysis of the {D}/{L} ratios, and (3) lithostratigraphic and geomorphic evaluation, three ( {D}/{L}) Stages are proposed. The {D}/{L} ratios for all the species measured are converted to a Patella vulgata standard. The three ( {D}/{L}) Stages are: (1) The Minchin Hole ( {D}/{L}) Stage, {D}/{L} ratios 0.175 ± 0.014, defined at a stratotype in Minchin Hole Cave, Gower, Wales. (2) A provisionally defined, but as yet, unamed ( {D}/{L}) Stage, because of the current unavailability of a suitable stratotype, with {D}/{L} ratios of 0.135 ± 0.014 (3) The Pennard ( {D}/{L}) Stage, {D}/{L} ratios 0.105 ± 0.016, defined at a stratotype in Minchin Hole Cave, Gower, Wales. Two geochronological models of the three high sea-level events representing the {D}/{L} Stages are constrained by uranium-series age determinations on stalagmite interbedded with marine beds in Minchin Hole and Bacon Hole Caves, Gower, Wales. A potential 'fixed point' in model evaluation is an age determination which is equivalent to Oxygen Isotope Sub-stage 5e (122 ka). The two models are:

Bowen, D. Q.; Sykes, G. A.; Reeves (nee Henry), Alayne; Miller, G. H.; Andrews, J. T.; Brew, J. S.; Hare, P. E.

345

Arthritis in a Glyptodont (Mammalia, Xenarthra, Cingulata)  

PubMed Central

Arthritic lesions have been frequently diagnosed in the fossil record, with spondyloarthropathy (a type of erosive and pan-mammalian arthritis) being one of the most common types described to date for mammals, though not restricted to this group. Here, we identify spondyloarthropathy in fossil bones from the late Pleistocene in Brazil assignable to a large glyptodont individual. Bone erosions in the peripheral joints (viz., the ulna, radius, left femur and tibiae-fibulae) associated with osteosclerosis allow the diagnosis of spondyloarthropathy. The presence of osteophytes in seven bones of the forelimbs (viz., the ulna and radius) and hind limbs (viz., the tibiae-fibulae, left femur and patellae) and a subchondral cyst in one element (viz., the left femur) indicate secondary osteoarthritis. A calcified deposition on the articular surface of the left patella indicates the presence of calcium pyrophosphate deposition disease, which, like the observed osteoarthritic alterations, likely represents a complication of spondyloarthropathy. This is the first report of spondyloarthropathy for xenarthrans. PMID:24551126

Barbosa, Fernando Henrique de Souza; Porpino, Kleberson de Oliveira; Fragoso, Ana Bernadete Lima; Oliveira, Edison Vicente

2014-01-01

346

Longitudinal changes in bone lead levels: the VA Normative Aging Study  

PubMed Central

Objective Bone lead is a cumulative measure of lead exposure that can also be remobilized. We examined repeated measures of bone lead over 11 years to characterize long-term changes and identify predictors of tibia and patella lead stores in an elderly male population. Methods Lead was measured every 3–5 years by k-x-ray fluorescence and mixed-effect models with random effects were used to evaluate change over time. Results 554 participants provided up to 4 bone lead measurements. Final models predicted a ?1.4% annual decline (95%CI: ?2.2,?0.7) for tibia lead and piecewise linear model for patella with an initial decline of 5.1% per year (95%CI: ?6.2,?3.9) during the first 4.6 years but no significant change thereafter (?0.4% (95% CI: ?2.4, 1.7)). Conclusions These results suggest that bone lead half-life may be longer than previously reported. PMID:21788910

Wilker, Elissa; Korrick, Susan; Nie, Linda H; Sparrow, David; Vokonas, Pantel; Coull, Brent; Wright, Robert O.; Schwartz, Joel; Hu, Howard

2011-01-01

347

Principal component analysis in construction of 3D human knee joint models using a statistical shape model method.  

PubMed

The statistical shape model (SSM) method that uses 2D images of the knee joint to predict the three-dimensional (3D) joint surface model has been reported in the literature. In this study, we constructed a SSM database using 152 human computed tomography (CT) knee joint models, including the femur, tibia and patella and analysed the characteristics of each principal component of the SSM. The surface models of two in vivo knees were predicted using the SSM and their 2D bi-plane fluoroscopic images. The predicted models were compared to their CT joint models. The differences between the predicted 3D knee joint surfaces and the CT image-based surfaces were 0.30 ± 0.81 mm, 0.34 ± 0.79 mm and 0.36 ± 0.59 mm for the femur, tibia and patella, respectively (average ± standard deviation). The computational time for each bone of the knee joint was within 30 s using a personal computer. The analysis of this study indicated that the SSM method could be a useful tool to construct 3D surface models of the knee with sub-millimeter accuracy in real time. Thus, it may have a broad application in computer-assisted knee surgeries that require 3D surface models of the knee. PMID:24156375

Tsai, Tsung-Yuan; Li, Jing-Sheng; Wang, Shaobai; Li, Pingyue; Kwon, Young-Min; Li, Guoan

2015-05-01

348

Barriers to gene flow in the marine environment: insights from two common intertidal limpet species of the Atlantic and Mediterranean.  

PubMed

Knowledge of the scale of dispersal and the mechanisms governing gene flow in marine environments remains fragmentary despite being essential for understanding evolution of marine biota and to design management plans. We use the limpets Patella ulyssiponensis and Patella rustica as models for identifying factors affecting gene flow in marine organisms across the North-East Atlantic and the Mediterranean Sea. A set of allozyme loci and a fragment of the mitochondrial gene cytochrome C oxidase subunit I were screened for genetic variation through starch gel electrophoresis and DNA sequencing, respectively. An approach combining clustering algorithms with clinal analyses was used to test for the existence of barriers to gene flow and estimate their geographic location and abruptness. Sharp breaks in the genetic composition of individuals were observed in the transitions between the Atlantic and the Mediterranean and across southern Italian shores. An additional break within the Atlantic cluster separates samples from the Alboran Sea and Atlantic African shores from those of the Iberian Atlantic shores. The geographic congruence of the genetic breaks detected in these two limpet species strongly supports the existence of transpecific barriers to gene flow in the Mediterranean Sea and Northeastern Atlantic. This leads to testable hypotheses regarding factors restricting gene flow across the study area. PMID:23239977

Sá-Pinto, Alexandra; Branco, Madalena S; Alexandrino, Paulo B; Fontaine, Michaël C; Baird, Stuart J E

2012-01-01

349

Vastus medialis obliquus muscle morphology in primary and recurrent lateral patellar instability.  

PubMed

The morphology of the vastus medialis obliquus (VMO) muscle in the anatomical setting of an unstable patella has not been described. Therefore, the purpose of this study was to investigate the morphological parameters of the VMO muscle that delineate its importance in the maintenance of patellofemoral joint stability. Eighty-two consecutive subjects were prospectively enrolled in this study. The groups were composed of thirty patients with an acute primary patellar dislocation, thirty patients with recurrent patellar dislocation, and twenty-two controls. Groups were adjusted according to sex, age, body mass index, and physical activity. Magnetic resonance imaging was used to measure the VMO cross-sectional area, muscle-fiber angulation, and the craniocaudal extent of the muscle in relation to the patella. No significant difference was found with respect to all measured VMO parameters between primary dislocation, recurrent dislocation, and control subjects with a trend noted for only the VMO cross-sectional area and the VMO muscle-fiber angulation. This finding is notable in that atrophy of the VMO has often been suggested to play an important role in the pathophysiology of an unstable patellofemoral joint. PMID:24868524

Balcarek, Peter; Oberthür, Swantje; Frosch, Stephan; Schüttrumpf, Jan Philipp; Stürmer, Klaus Michael

2014-01-01

350

Medial Patellofemoral Ligament Reconstruction Procedure Using a Suspensory Femoral Fixation System  

PubMed Central

Recurrent patellar dislocation has recently been treated with anatomic medial patellofemoral ligament (MPFL) reconstruction using a semitendinosus muscle tendon. Although it is necessary to add tension to fix the tendon graft without loading excess stress on the patellofemoral joint, adjustment of the tension can be difficult. To resolve this problem, we developed an MPFL reconstruction procedure using the ToggleLoc Fixation Device (Biomet, Warsaw, IN), in which the semitendinosus muscle tendon is folded and used as a double-bundle tendon graft and 2 bone tunnels and 1 bone tunnel are made on the patellar and femoral sides, respectively. The patellar side of the tendon graft is fixed with an EndoButton (Smith & Nephew, London, England), and the femoral side is fixed with the ToggleLoc. Stepless adjustment of tension of the tendon graft is possible by reducing the size of the loop of the ToggleLoc hung onto the tendon graft. It may be useful to position the patella in the center of the femoral sulcus by confirming the patellofemoral joint fitting. Stability can be confirmed by loading lateral stress on the patella in the extended knee joint. This procedure is less invasive because opening of the lateral side of the femur is not necessary, and it may be useful for MPFL reconstruction. PMID:24892014

Nakagawa, Shuji; Arai, Yuji; Kan, Hiroyuki; Ueshima, Keiichiro; Ikoma, Kazuya; Terauchi, Ryu; Kubo, Toshikazu

2013-01-01

351

A minimally invasive medial patellofemoral ligament arthroscopic reconstruction.  

PubMed

The medial patellofemoral ligament reconstruction is recognized as a good choice for patients with recurrent patellar dislocation. Most techniques of the medial patellofemoral ligament reconstruction are open surgeries. Recently, we present a minimally invasive medial patellofemoral ligament arthroscopic reconstruction technique as a possible alternative method for recurrent patellar dislocation. The aim of the study was to describe a safe and effective technique to perform medial patellofemoral ligament reconstruction. The graft was prepared in shape to "Y." Two 5-mm incisions were made in the skin above the medial edge of the patella. Two docking bone tunnels were drilled from medial edge to the center of the patella, mimicking the wide patellar insertion of the medial patellofemoral ligament, and a bone tunnel was made at the femoral insertion site. Two free ends of the graft were fixed into the patellar tunnels by lateral cortical suspension, and the folded end was fixed into the femoral tunnel by bioabsorbable interference screw. Average patellar tilt and the congruence angle were 30.7° ± 7.5° and 52.7° ± 7.3° and were reduced to 12.8° ± 0.9° and 2.3° ± 11.5° after treatment. The Kujala score was increased from 63.0 ± 9.0 to 91.0 ± 7.0. The minimally invasive medial patellofemoral ligament arthroscopic reconstruction in this paper seems to be helpful to increase safe of operation and treatment effect and reduce complications. PMID:23412307

Zhou, Jian-Wei; Wang, Cheng-Hai; Ji, Gang; Ma, Long-Fei; Wang, Juan; Zhang, Feng; Dong, Jiang-Tao; Wang, Fei

2014-02-01

352

Barriers to Gene Flow in the Marine Environment: Insights from Two Common Intertidal Limpet Species of the Atlantic and Mediterranean  

PubMed Central

Knowledge of the scale of dispersal and the mechanisms governing gene flow in marine environments remains fragmentary despite being essential for understanding evolution of marine biota and to design management plans. We use the limpets Patella ulyssiponensis and Patella rustica as models for identifying factors affecting gene flow in marine organisms across the North-East Atlantic and the Mediterranean Sea. A set of allozyme loci and a fragment of the mitochondrial gene cytochrome C oxidase subunit I were screened for genetic variation through starch gel electrophoresis and DNA sequencing, respectively. An approach combining clustering algorithms with clinal analyses was used to test for the existence of barriers to gene flow and estimate their geographic location and abruptness. Sharp breaks in the genetic composition of individuals were observed in the transitions between the Atlantic and the Mediterranean and across southern Italian shores. An additional break within the Atlantic cluster separates samples from the Alboran Sea and Atlantic African shores from those of the Iberian Atlantic shores. The geographic congruence of the genetic breaks detected in these two limpet species strongly supports the existence of transpecific barriers to gene flow in the Mediterranean Sea and Northeastern Atlantic. This leads to testable hypotheses regarding factors restricting gene flow across the study area. PMID:23239977

Sa-Pinto, Alexandra; Branco, Madalena S.; Alexandrino, Paulo B.; Fontaine, Michael C.; Baird, Stuart J. E.

2012-01-01

353

Painful Knee Prosthesis: Surgical Approach  

PubMed Central

A painful knee prosthesis is, unfortunately, a condition whose possible causes are not always easily diagnosed. As a consequence, it can be difficult to resolve. Common causes of prosthetic failure, such as aseptic loosening, infection, instability, progressive patellar arthropathy and recurrent synovitis are associated with clearly defined radiographic and/or clinical evidence. Blood chemistry tests for indicators of infection and synovial fluid culture are always to be considered of primary importance in the diagnostic work up of a painful prosthesis, given that, in this situation, prosthetic infection should always be considered first, and remain a possibility until some other causes has been demonstrated. In the presence of an infected prosthesis we carry out a two-step revision, first using an articulating antibiotic-impregnated cement spacer with two mono-compartment components to preserve the range of movement; subsequently, after the infection has been resolved, we carry out new prosthetic surgery, generally using prostheses of increasing stability and bone grafts, depending on the residual bone stock. Aseptic loosening of a knee prosthesis is a complication that is easily identified radiographically due to the presence of lines of radiolucency at the bone/prosthesis interface, associated with migration or angulation of the components. In these cases, it is necessary to revise the prosthesis, increasing its stability with diaphyseal shafts. With regard to this problem, we have, recently, also been evaluating the opportuneness and efficacy of pre- and post-operative treatment with bone-forming agents in patients with poor bone quality, in order to reduce the risk of loosening and extend the life of the prosthesis. Varus-valgus, anteroposterior, global patellofemoral instability are failures, often due to technical errors, that can be diagnosed through clinical examination. In the presence of a painful prosthesis associated with frank instability, we perform revision using superstabilised or constrained implants, depending on the particular case. Nevertheless, the diagnosis and treatment of a painful knee prosthesis can be extremely difficult if there is no clear evidence of any of the most common causes of failure. In the presence of prosthetic components having large diaphyseal shafts, a sharp pain can be detected; in these situations, it is sometimes possible to observe, on radiographic examinations, effects of periprosthetic stress shielding. To resolve the problem the component would have to be replaced with one having a shaft with a smaller diameter. A painful prosthesis accompanied by a patellar clunk can be attributed to the formation of a subquadricipital fibrous nodule proximal to the patella which can be responsable of impingement with the anterior margin of the posterior-stabilising femoral component box. Arthroscopic removal of the fibrous nodule will, in this case, resolve the pain. Recurrent synovitis can also be effectively treated arthroscopically. If pain is of patellofemoral origin, it is necessary, in the case of a prosthetic patella, to evaluate the stability of the component and any alterations in its motion. As far as the surgical technique is concerned, in cases in which patellar lateralisation is performed, medialising the button so as to obtain improved tracking, we recommend not using too small a patellar component and performing an oblique osteotomy laterally to the button in order to reduce the risk of pain due to non-lined patella/femoral component interference. In the presence of a natural patella progressive arthropathy can often cause late-onset knee pain at anterior patellar level; in this case, prosthetic patella insertion is needed with, in the event of altered tracking, lateral release. In some cases patellofemoral pain is related to misalignment of the components, which can be evaluated precisely through the superimposition of references in CT images. In this situation it is essential to perform a revision of the prosthesis, seeking to obtain the correct rotations and correct m

Villano, M.; Puccini, S.; Soderi, S.; Innocenti, M.

2010-01-01

354

A Clinical and Radiographic Approach for Establishing Proper Tibial Tubercle Transfer when using Quad Active Femoral Nerve Stimulation  

PubMed Central

Background The tibial tubercle-trochlear groove measurement (TT-TG), which measures the lateral offset of the tibial tubercle relative to the trochlear groove of the femur, has been utilized as an intraoperative tool to help establish maximum patellofemoral congruency in patients who suffer from patellar instability. We have previously published our approach of establishing how far to transfer the tibial tubercle using intraoperative femoral nerve stimulation in order to achieve congruency from 0-30° of flexion. The technique and clinical outcomes have previously been published in this journal and elsewhere. Here we describe the use of the TT-TG distance to determine how far to transfer the tibial tubercle to achieve our goals and have found that it varies according to the clinical exam features. Purpose We intended to determine the effectiveness of using the preoperatively established TT-TG to predict the degree of intraoperative me- dialization of the tibial tubercle to achieve our goal of establishing dynamic congruency of the patella in the trochlear groove when using the previously described femoral nerve stimulation method of estimating dynamic tracking of the patella. Methods From the study group of patients used in other publications, we examined 20 knees in 18 patients who had a history of recurrent lateral dislocations and underwent a Fulkerson tibial tubercle transfer. Each knee was dynamically assessed preoperatively by obtaining an MRI at 30° of flexion and complete hyperextension while voluntarily contracting their quadriceps. These were then compared to the intraoperative transfer of the tibial tubercle required to achieve maximum congruency when the femoral nerve was stimulated. We then looked at the preoperative TT-TG measurement to determine its role in predicting what was required at achieving congruency in the context of the quad active MRI findings. Results Thirteen knees preoperatively demonstrated a positive J-sign defined as the patella subluxated greater than or equal to 5mm lateral in full extension compared to 30° of flexion. In these patients, the TT-TG was accurate if the distance medialized was 1:1 with the measured TT-TG. In 7 out of the 20 knees, the patella demonstrated a false negative J-sign where the patella was radio- graphically subluxated at 30° of flexion as well as at hyperextension. In this group, the TT-TG underestimated the transfer required for congruency on average 5mm even when using the 1:1 ratio. Conclusions The preoperative use of the J-sign is of value when determining the role of the TT-TG measurement and estimating the distance required to intraoperatively achieve congruency when using the femoral nerve stimulation technique. Those that demonstrated a positive J-sign of 5mm or greater, a 1:1 ratio of TT-TG to medialization is most reliable at establishing congruency of the patellofemoral joint. Whereas, those that demonstrated a false negative J-sign even the 1:1 ratio remains inadequate at producing congruency and more medialization is required. Level of evidence Level III, Retrospective Observational/Comparative Study PMID:24027466

McDermott, Scott E.; Anthony, Chris A.; McCunniff, Pete; Duchman, Kyle; Albright, John P.

2013-01-01

355

Cumulative lead exposure in community-dwelling adults and fine motor function: comparing standard and novel tasks in the VA Normative Aging Study  

PubMed Central

Background and Aims Lead exposure in children and occupationally-exposed adults has been associated with reduced visuomotor and fine motor function. However, associations in environmentally-exposed adults remain relatively unexplored. To address this, we examined the association between cumulative lead exposure—as measured by lead in bone—and performance on the Grooved Pegboard (GP) manual dexterity task, as well as on handwriting tasks using a novel assessment approach, among men in the VA Normative Aging Study (NAS). Methods GP testing was done with 362 NAS participants, and handwriting assessment with 328, who also had tibia and patella lead measurements made with K-X-Ray Fluorescence (KXRF). GP scores were time (sec) to complete the task with the dominant hand. The handwriting assessment approach assessed the production of signature and cursive lowercase l and m letter samples. Signature and lm task scores reflect consistency in repeated trials. We used linear regression to estimate associations and 95% confidence intervals (CI) with adjustment for age, smoking, education, income and computer experience. A backward elimination algorithm was used in the subset with both GP and handwriting assessment to identify variables predictive of each outcome. Results The mean (SD) participant age was 69.1 (7.2) years; mean patella and tibia concentrations were 25.0 (20.7) ?g/g and 19.2 (14.6) ?g/g, respectively. In multivariable-adjusted analyses, GP performance was associated with tibia (? per 15 ?g/g bone = 4.66, 95% CI: 1.73, 7.58, p=0.002) and patella (? per 20 ?g/g = 3.93, 95% CI: 1.11, 6.76, p = 0.006). In multivariable adjusted models of handwriting production, only the lm-pattern task showed a significant association with tibia (? per 15 ?g/g bone = 1.27, 95% CI: 0.24, 2.29, p = 0.015), such that lm pattern production was more stable with increasing lead exposure. GP and handwriting scores were differentially sensitive to education, smoking, computer experience, financial stability, income and alcohol consumption. Conclusions Long-term cumulative environmental lead exposure was associated with deficits in GP performance, but not handwriting production. Higher lead appeared to be associated with greater consistency on the lm task. Lead sensitivity differences could suggest that lead affects neural processing speed rather than motor function per se, or could result from distinct brain areas involved in the execution of different motor tasks. PMID:23370289

Grashow, Rachel; Spiro, Avron; Taylor, Kathryn M.; Newton, Kimberly; Shrairman, Ruth; Landau, Alexander; Sparrow, David; Hu, Howard; Weisskopf, Marc

2013-01-01

356

Role of pathophysiology of patellofemoral instability in the treatment of spontaneous medial patellofemoral subluxation: a case report  

PubMed Central

Introduction Medial patellar subluxation is usually seen after lateral retinacular release. Spontaneous medial subluxation of the patella is a very rare condition. There are few reports in the literature on the pathophysiology of iatrogenic medial patellar subluxation. To our knowledge, there are no reports of the pathophysiology of non-iatrogenic medial patellar subluxation in the English literature. In this study we present a case of spontaneous medial patellar instability that is more prominent in extension during weight bearing. We also try to define the treatment protocol based on pathophsiology. Case presentation We report the case of a 21-year-old Turkish man with spontaneous medial patellar instability. He had suffered right knee pain, clicking and popping sensation in the affected knee for three months prior to presentation. Clinical examination demonstrated medial patellar subluxation that is more prominent in extension during the weight bearing phase of gait and while standing. Increased medial tilt was observed when the patella was stressed medially. Conventional anterior to posterior, lateral and Merchant radiographs did not reveal any abnormalities. After three months of physical therapy, our patient was still suffering from right knee pain which disturbed his gait pattern. Throughout the surgery, medial patellar translation was tested following the imbrication of lateral structures. He still had a medial patellar translation that was more than 50% of his patellar width. Patellotibial ligament augmentation using an iliotibial band flap was added. When examined after surgery, the alignment of the patella was effectively corrected. Conclusions Chronic imbalance between the strengths of vastus lateralis and vastus medialis results in secondary changes in passive ligamentous structures and causes additional instability. Physical therapy modalities that aim to strengthen the vastus lateralis might be sufficient for the treatment of spontaneous medial instability. There would be no need for any surgical intervention if spontaneous medial instability was recognized before the additional instability occured. If necessary, lateral imbrication followed by lateral patellotibial ligament augmentation can be performed, and these would effectively correct spontaneous medial patellofemoral instability. PMID:20492715

2010-01-01

357

Mathematical simulations of photon interactions using Monte Carlo analysis to evaluate the uncertainty associated with in vivo K X-ray fluorescence measurements of stable lead in bone  

NASA Astrophysics Data System (ADS)

This research utilized Monte Carlo N-Particle version 4C (MCNP4C) to simulate K X-ray fluorescent (K XRF) measurements of stable lead in bone. Simulations were performed to investigate the effects that overlying tissue thickness, bone-calcium content, and shape of the calibration standard have on detector response in XRF measurements at the human tibia. Additional simulations of a knee phantom considered uncertainty associated with rotation about the patella during XRF measurements. Simulations tallied the distribution of energy deposited in a high-purity germanium detector originating from collimated 88 keV 109Cd photons in backscatter geometry. Benchmark measurements were performed on simple and anthropometric XRF calibration phantoms of the human leg and knee developed at the University of Cincinnati with materials proven to exhibit radiological characteristics equivalent to human tissue and bone. Initial benchmark comparisons revealed that MCNP4C limits coherent scatter of photons to six inverse angstroms of momentum transfer and a Modified MCNP4C was developed to circumvent the limitation. Subsequent benchmark measurements demonstrated that Modified MCNP4C adequately models photon interactions associated with in vivo K XRF of lead in bone. Further simulations of a simple leg geometry possessing tissue thicknesses from 0 to 10 mm revealed increasing overlying tissue thickness from 5 to 10 mm reduced predicted lead concentrations an average 1.15% per 1 mm increase in tissue thickness (p < 0.0001). An anthropometric leg phantom was mathematically defined in MCNP to more accurately reflect the human form. A simulated one percent increase in calcium content (by mass) of the anthropometric leg phantom's cortical bone demonstrated to significantly reduce the K XRF normalized ratio by 4.5% (p < 0.0001). Comparison of the simple and anthropometric calibration phantoms also suggested that cylindrical calibration standards can underestimate lead content of a human leg up to 4%. The patellar bone structure in which the fluorescent photons originate was found to vary dramatically with measurement angle. The relative contribution of lead signal from the patella declined from 65% to 27% when rotated 30°. However, rotation of the source-detector about the patella from 0 to 45° demonstrated no significant effect on the net K XRF response at the knee.

Lodwick, Camille J.

358

Illness perceptions and activity limitations in osteoarthritis of the knee: a case report intervention study.  

PubMed

This case report describes the process and outcome of an intervention where illness perceptions (IPs) were targeted in order to reduce limitations in daily activities. The patient was a 45-year-old woman diagnosed with posttraumatic secondary osteoarthritis of the lateral patella-femoral cartilage of the right knee. At baseline, the patient reported maladaptive IPs on the Brief Illness Perception Questionnaire Dutch Language Version and limitations in walking stairs, cycling and walking. Fewer limitations in daily activities are hypothesized by changing maladaptive IPs into more favourable IPs. In this case report, discussing maladaptive IPs with the patient was the main intervention. A participatory decision making model was used as a design by which the maladaptive IP were discussed. Six out of eight maladaptive IPs changed favourably and there was a clinically relevant decrease in limitations of daily activities. The Global Perceived Effect was rated as much improved. PMID:24011782

de Raaij, Edwin J; Pool, Jan; Maissan, François; Wittink, Harriët

2014-04-01

359

Bone Ingrowth in Well-Fixed Retrieved Porous Tantalum Implants  

PubMed Central

While first generation porous coatings have had clinical success, aseptic loosening remains a leading cause of revision. The purpose of this study was to investigate the reason for revision and to assess the amount of bone ingrowth in retrieved porous tantalum components. In a prospective multicenter retrieval program, 76 porous tantalum acetabular shells, 5 femoral stems, 7 patellas and 36 tibial trays were collected from revision surgeries. A subset of the implants were analyzed for bone ingrowth. The main reason for revision was infection for acetabular shells (1.4 year implantation time) and instability for tibial trays (1.8 years implantation time). Two of the thirty primary surgery acetabular shells and one of the thirty-six primary surgery tibial trays were revised for implant loosening. We observed full depth penetration of bone into the porous tantalum layer for the acetabular shells and femoral stems. PMID:23518432

Hanzlik, Josa A.; Day, Judd S.

2013-01-01

360

Clinical results of patellofemoral arthroplasty.  

PubMed

Isolated patellofemoral arthritis can be a disabling condition that can be challenging to treat. Patients with symptoms recalcitrant to conservative measures are considered for total or partial knee arthroplasty. This retrospective study reports the results of patellofemoral arthroplasty at a single center using a variety of implant designs. Thirty patients (37 knees) with isolated patellofemoral disease treated with patellofemoral arthroplasty with a minimum of one year follow-up were evaluated. The majority of patients were female (83%) and the underlying diagnosis was osteoarthritis in 98% of knees. Reported follow-up averaged 31 months. Average Knee Society Pain, Functional, and Clinical Scores improved from pre-op to most recent follow-up. Two complications (5.4%) required intervention. One patient was converted to a total knee arthroplasty secondary to patella instability. PMID:23790605

Morris, Michael J; Lombardi, Adolph V; Berend, Keith R; Hurst, Jason M; Adams, Joanne B

2013-10-01

361

Anatomic reconstruction of the medial patellofemoral ligament in children and adolescents using a pedicled quadriceps tendon graft.  

PubMed

Reconstruction of the medial patellofemoral ligament (MPFL) has recently become a popular procedure for children and adolescents with patellofemoral instability. Nevertheless, high complication rates of up to 26% have been reported. The traditionally used technique requires patellar bone tunnels that may place the proportionately smaller patella at higher risk of fracture. Because of the adjacent physis of the femoral insertion, anatomic reconstruction of the MPFL has the risk of injury to the growth plate. This technical report therefore presents a technique for anatomic reconstruction of the MPFL in a skeletally immature population using a pedicled superficial quadriceps tendon graft, hardware-free patellar graft attachment, and anatomic femoral fixation distal to the femoral physis. The advantages of this technique include avoidance of bony patellar complications, an anatomically truer reconstruction, a single incision, and sparing of the hamstring tendons for reconstruction of any future ligamentous injuries. PMID:24904782

Nelitz, Manfred; Williams, Sean Robert M

2014-04-01

362

The use of rapid prototyped implants to simulate knee joint abnormalities for in vitro testing: a validation study with replica implants of the native trochlea.  

PubMed

To investigate the biomechanical effect of skeletal knee joint abnormalities, the authors propose to implant pathologically shaped rapid prototyped implants in cadaver knee specimens. This new method was validated by replacing the native trochlea by a replica implant on four cadaver knees with the aid of cadaver-specific guiding instruments. The accuracy of the guiding instruments was assessed by measuring the rotational errors of the cutting planes (on average 3.01° in extension and 1.18° in external/internal rotation). During a squat and open chain simulation, the patella showed small differences in its articulation with the native trochlea and the replica trochlea, which could partially be explained by the rotational errors of the implants. This study concludes that this method is valid to investigate the effect of knee joint abnormalities with a replica implant as a control condition to account for the influence of material properties and rotational errors of the implant. PMID:25205750

Van Haver, Annemieke; De Roo, Karel; De Beule, Matthieu; Van Cauter, Sofie; Labey, Luc; De Baets, Patrick; Claessens, Tom; Verdonk, Peter

2014-08-01

363

Bone ingrowth in well-fixed retrieved porous tantalum implants.  

PubMed

While first generation porous coatings have had clinical success, aseptic loosening remains a leading cause of revision. The purpose of this study was to investigate the reasons for revision and to assess the amount of bone ingrowth in retrieved porous tantalum components. In a prospective multicenter retrieval program, 76 porous tantalum acetabular shells, 5 femoral stems, 7 patellas and 36 tibial trays were collected from revision surgeries. A subset of the implants was analyzed for bone ingrowth. The main reason for revision was infection for acetabular shells (1.4 years implantation time) and instability for tibial trays (1.8 years implantation time). Two of the thirty primary surgery acetabular shells and one of the thirty-six primary surgery tibial trays were revised for implant loosening. We observed full depth penetration of bone into the porous tantalum layer for the acetabular shells and femoral stems. PMID:23518432

Hanzlik, Josa A; Day, Judd S

2013-06-01

364

Report of prochloron research, IPE-7 (Palau, February 1982)  

NASA Technical Reports Server (NTRS)

Various aspects of Prochloron research are discussed. At suitable low-tide periods about 5-6 new sites were surveyed as possible convenient sources of symbiotic didemnids. The Kanori Channel site peviously surveyed during IPE-VI remains by far the best, in terms of species, quantities and accessibility. Prochloron from the six major species of symbiotic didemnids was compared serum, cell size and vacuolation, etc. Tadpoles from Lissoclinum patella colonies were observed emerging from cloacal apertures; about 400 were collected. All but 4 carried a girdle of symbiotic Prochloron cells (about 40,000 per larva). Observations were made on cell viability indicated that a marked increase in protoplasm viscosity of the cell contents was associated with cell death. Living cells, in 5 microlitres of buffered sea water under a coverslip, when pressed with a 2 kg weight for 10 seconds, attempts made to culture Prochloron in sea-water media.

Lewin, R. A.; Cheng, L.

1983-01-01

365

The effect of McConnell taping on vastus medialis and lateralis activity during squatting in adults with patellofemoral pain syndrome  

PubMed Central

This study aims to examine the effect of McConnell taping to patients with patellofemoral pain syndrome on the change of the muscle activity of vastus medialis and vastus lateralis during squatting. The total numbers of participants are 16 patients with pain in their knee. There are three different experiments: no-taping, placebo taping, and McConnell taping. As a result, both the muscle activity of vastus medialis and muscle activity ratio of vastus medialis to vastus lateralis increased in placebo taping compared to no-taping, which wasn’t statistically significant. However, the muscle activity of vastus medialis and muscle activity ratio of vastus medialis to vastus lateralis increased in McConnell taping compared to no-taping, which was statistically significant. These results suggest that McConnell taping affects the activity of quadriceps by changing the position of the patella, and thus can effectively be applied in the treatment of patellofemoral pain syndrome. PMID:24278879

Lee, Sung-Eun; Cho, Sung-Hyoun

2013-01-01

366

Comparison of three-dimensional patellofemoral joint reaction forces in persons with and without patellofemoral pain.  

PubMed

The purpose of this study was to determine if persons with patellofemoral pain (PFP) exhibit differences in patellofemoral joint reaction forces (PFJRFs) during functional activities. Forty females (20 PFP, 20 controls) underwent two phases of data collection: (1) magnetic resonance imaging (MRI) and (2) biomechanical analysis during walking, running, stair ascent, and stair descent. A previously described three-dimensional model was used to estimate PFJRFs. Resultant PFJRFs and the orthogonal components were reported. The PFP group demonstrated lower peak resultant PFJRFs and posterior component and superior component of the PFJRFs compared with the control group across all conditions. However, the PFP group had a higher peak lateral component of the PFJRF in three out of the four conditions evaluated. The lower resultant PFJRFs suggested that individuals with PFP may employ strategies to minimize patellofemoral joint loading, but it did not result in diminished lateral forces acting on the patella. PMID:24603612

Chen, Yu-Jen; Powers, Christopher M

2014-08-01

367

The Prochloron symbiosis  

NASA Technical Reports Server (NTRS)

Colonies of L. patella were collected from inshore water adjacent to small islets near Babelthaup Island, Republic of Palau, for the purpose of studying Prochloron symbionts. Examination of the algal symbionts after fixing, dehydrating, and embedment in Epon, showed Prochloron's central body to consist of a granular ground substance with a few electron-dense inclusions and to be enclosed by prominent photosynthetic membranes. Also found around the central body were thylakoids in a concentric pattern. After comparing the results with those of former studies, it was suggested that Prochloron morphology is host specific. Finally the network of host tissue extensions that entraps the symbionts was noted as possibly being a site for metabolic exchange.

Pardy, R. L.; Lee, K.; Lewin, R. A.

1984-01-01

368

Patellotibial external fixation for ruptures of the distal extensor apparatus of the knee  

Microsoft Academic Search

Summary\\u000a Objectives  The Marburg external patellotibial (Mpt) fixator is designed to temporarily protect a reconstructed distal extensor apparatus\\u000a of the knee. It allows an early functional aftercare.\\u000a \\u000a \\u000a \\u000a \\u000a Indications  Acute and chronic disruptions of the distal extensor apparatus.\\u000a \\u000a \\u000a \\u000a Contraindications  Severe metabolic diseases.\\u000a \\u000a Previous bone and\\/or soft tissue infection.\\u000a \\u000a \\u000a Uncooperative patient.\\u000a \\u000a \\u000a \\u000a \\u000a Surgical Technique  \\u000a Assembly A: insertion of a threaded pin into the patella perpendicular to

Bernd Ishaque; Ewgeni Ziring; Jörg Petermann; Leo Gotzen

2000-01-01

369

Post impingement in posterior stabilised total knee arthroplasty.  

PubMed

Posterior stabilised implants are a well-proven treatment for patients requiring primary total knee arthroplasty. Concerns about the posterior stabilised (PS) design have been raised and recent studies suggest that the post-cam articulation can be an additional source of polyethylene wear debris. In this study, the authors report impingement of the tibial post against the patellar component in deep flexion in posterior stabilised total knee arthroplasty. Their data suggest that "post impingement" is associated with a raised joint line, patella infera, too anterior placement of the tibial component and a smaller femoral component size. "Post impingement" may lead to extensor mechanism problems and additional polyethylene wear and therefore may affect the longterm functional results of posterior stabilised total knee arthroplasty. PMID:15055317

Verborgt, Olivier; Victor, Jan

2004-02-01

370

Dissemination of metals from a failed patellar component made of titanium-base alloy.  

PubMed

Complications related to the patella are the most common problems in total knee arthroplasty and major reasons for revision surgery. Among patellofemoral problems, metal-to-metal contact between patellar and femoral components is the worst. We measured levels of titanium, aluminum, and vanadium in serum and urine samples and compared these measures from cases in which metal-to-metal contact of the patellar component occurred with those in cases in which only polyethylene wear occurred. Serum levels of the metals in cases with metal-to-metal contact were over 10 times higher than those in cases without metal-to-metal contact. This suggests that different ranges of serum metal ion levels could eventually be correlated with a variety of mechanisms of patellar failure. Therefore, cases with metal-to-metal contact should be distinguished from cases without metal-to-metal contact. These should not be considered as a single group in patellar component failure. PMID:14566752

Takai, Shinro; Yoshino, Nobuyuki; Kusaka, Yoshiaki; Watanabe, Yoshinobu; Hirasawa, Yasusuke

2003-10-01

371

The use of limpets as monitor of PAHs pollution in the Cantabrian coast  

NASA Astrophysics Data System (ADS)

The concentrations of 24 parental and methylated polycyclic aromatic hydrocarbon (PAH) levels in common limpet ( Patella vulgata) were measured in 15 coastal localities of the southern Bay of Biscay and 2 sites per locality for 2 years (spring and autumn of 2004 and 2005, respectively). Although the average concentrations shown a wide variability among the sites and the season, several sites showed a remarkable high concentration (PAH tot>900 ng g -1 d.w.) or medium (300-800 ng g -1 d.w) levels, but in most of the cases the initial high concentrations decreased sharply from one campaign to the following. Moreover, based on ratios of individual isomers concentration, petrogenic and pyrolitic sources were distinguished suggesting more than one source. Finally, based on the results of this work and comparing with previously reported data, it can concluded that limpets can be used as sentinel organisms in coastal environmental monitoring, even when oil spills are involved.

Bartolomé, L.; Bustamante, M.; Navarro, P.; Tajadura, J.; Gorostiaga, J. M.; Díez, I.; Zuloaga, O.; Etxebarria, N.

2011-11-01

372

Low-pass filtering of noisy field Schlumberger sounding curves. Part II: Application  

SciTech Connect

The basic principles of the application of the linear system theory for smoothing noise-degraded d.c. geoelectrical sounding curves were recently established by Patella. A field Schlumberger sounding is presented to demonstrate first their application and validity. To achieve this purpose, firstly it is pointed out that the required smoothing or low-pass filtering can be considered as an intrinsic property of the transformation of original Schlumberger sounding curves into pole-pole (two-electrode) curves. Then the authors sketch a numerical algorithm to perform the transformation, opportunely modified from a known procedure for transforming dipole diagrams into Schlumberger ones. Finally they show a field example with the double aim of demonstrating (i) the high quality of the low-pass filtering, and (ii) the reliability of the transformed pole-pole curve as far as quantitative interpretation is concerned.

Ghosh, N.; Wadhwa, R.S.; Shrotri, B.S.; Patella, D.

1986-02-01

373

Imaging of the skeleton and soft tissue in children.  

PubMed

Normal metaphyses in infants contain a step-off not to be confused with child abuse. Extension of physeal lucency into the metaphyses can be a sign of healing child-abuse fracture of experimental physeal fracture, as well as deferoxamine overdose. Sonography can reveal costochondral dislocation, the pattern of healing fracture callus, the patellar tendon in jumper's knee, synovium of rheumatoid arthritis, sequestrum in advanced osteomyelitis, the unossified dislocated patella, and, even after 2 years of age, the dislocated femoral head. Further developments concern bone scanning, MR imaging, CT, and plain films of specific trauma, tumor, and infectious, metabolic, and orthopaedic conditions. Ultrasound has been proven useful for radiologist removal of soft tissue foreign bodies, whereas CT can be helpful for osteoid osteoma nidus removal under imaging control. PMID:1751298

Oestreich, A E

1991-12-01

374

Minimally invasive Oxford unicompartmental knee arthroplasty: functional results at 1 year and the effect of surgical inexperience.  

PubMed

Oxford medial unicompartmental arthroplasty (UCA) is now routinely performed through a short incision without dislocation of the patella. We present the 1 year results of the first 104 knees operated in Oxford using this technique and the learning curve associated with it. The patient's average age at surgery was 68 years. The average American Knee Society 'knee score' improved from 37 to 94 points and the average 'functional score' from 50 to 92 points. Average maximum flexion improved from 117 to 131 degrees. The average knee score during a surgeon's first 10 cases was 88 points, which was significantly less (P<0.03) than the score achieved for subsequent cases after the first 10 (95 points). These data suggest for the first time that a learning curve exists with worse results being achieved during a surgeon's first 10 cases. However, the results during the learning curve are still similar to that achieved after total knee arthroplasty. PMID:15351410

Rees, J L; Price, A J; Beard, D J; Dodd, C A F; Murray, D W

2004-10-01

375

Microcephaly, short stature, and developmental delay associated with a chemotactic defect and transient hypogammaglobulinaemia in two brothers.  

PubMed Central

Two brothers presented with unusual facial features, microcephaly, developmental delay, and severe postnatal growth retardation. They both developed eczema in infancy and have had recurrent infections. Additional physical findings in both boys included hypogonadism, flexion contractures, hypoplastic patellae, and scoliosis. Their facial similarity was striking with sloping foreheads, beaked noses, large, protruding ears, and micrognathia. Low levels of serum gammaglobulins and defective chemotaxis were present in both boys in infancy. The hypogammaglobulinaemia was transient and improved, reaching normal levels by 3 1/2 years and 15 months, respectively. Defective chemotaxis and recurrent infections have persisted to the present. Both parents were normal. The mode of inheritance was not clear, as both X linked and autosomal recessive patterns were possible. Although patients with congenital malformations who also had immunodeficiency have previously been reported, immune system abnormalities, especially those of a transient nature, may frequently go unrecognised. Images PMID:3746838

Say, B; Barber, N; Miller, G C; Grogg, S E

1986-01-01

376

Comparison of robot surgery modular and total knee arthroplasty kinematics.  

PubMed

The kinematics of seven knee specimens were measured from 0 to 120 degrees flexion using an up-and-down crouching machine. Motion was characterized by the positions of the centers of the lateral and medial femoral condyles in the anterior-posterior direction relative to a fixed tibia. A modular unicompartmental knee, trochlea flange, and patella resurfacing (multicompartmental knee [MCK] system) were implanted using a surgeon-interactive robot system that provided accurate surface matching. The MCK was tested, followed by standard cruciate retaining (CR) and posterior stabilized (PS) knees. The motion of the MCK was close to anatomic, especially on the medial side, in contrast to the CR and PS knees that showed abnormal motion features. Such a modular knee system, accurately inserted, has the potential for close to normal function in clinical application. PMID:24227400

Yildirim, Gokce; Fernandez-Madrid, Ivan; Schwarzkopf, Ran; Walker, Peter S; Karia, Raj

2014-04-01

377

Isolated avulsion of the vastus lateralis tendon insertion in a weightlifter: a case report  

PubMed Central

Introduction We report a case of isolated, unilateral avulsion of the vastus lateralis tendon from its insertion at the patella. This was diagnosed by magnetic resonance imaging, and underwent successful surgical repair. Case presentation A healthy 32-year-old national level power lifter presented with an isolated avulsion of the vastus lateralis tendon. After a failed course of conservative therapy he underwent surgical repair and a graded physical therapy programme. One year later he returned to full training with no evidence of re-rupture. Conclusion This is the first reported case of an isolated vastus lateralis avulsion. Our experience suggests that magnetic resonance imaging is invaluable in the diagnosis of this condition and that surgical repair provides a good outcome in high demand patients. PMID:19918436

Trikha, Paul S; Wood, David G

2009-01-01

378

Patellofemoral pain: an update on diagnostic and treatment options.  

PubMed

Patellofemoral pain is a frequent and often challenging clinical problem. It affects females more than males and includes many different pathologic entities that result in pain in the anterior aspect of the knee. Diagnosis of the specific cause of pain can be difficult and requires assessment of lower extremity strength, alignment, and range of motion, as well as specific patella alignment, tracking, and mobility. The treatment for patellofemoral pain is usually conservative with anti-inflammatory medications, activity modification, and a specific physical therapy program focusing on strengthening and flexibility. Infrequently, surgical treatment may be indicated after a non-operative program fails. The outcomes of surgical management may include debridement, lateral release, and realignment of the extensor mechanism to unload the patellofemoral articulation are favorable. PMID:23456237

McCarthy, Moira M; Strickland, Sabrina M

2013-06-01

379

First-time patellar dislocation: surgery or conservative treatment?  

PubMed

Primary patellar dislocation injures the medial patellofemoral ligament (MPFL), the major soft-tissue stabilizer of the patella, which may lead to recurrent patellar instability. Recurrent patellar dislocation are common and may require surgical intervention. The variation in location of injury of the MPFL and the presence of an osteochondral fracture produces challenges in clinical decision making between nonoperative and operative treatment, including the surgical modality, to repair or reconstruct the MPFL. Current evidence suggests that not all primary dislocations should undergo the same treatment. MPFL reconstruction may theoretically be more reliable than repair, but the optimal time to perform additional bony corrections is not known. A normal or minor dysplastic patellofemoral joint may be suitable for nonoperative treatment, whereas a higher grade of trochlear dysplasia or other significant abnormalities may benefit from surgical treatment. In this paper, we present a treatment algorithm for primary patellar dislocation. PMID:22878653

Sillanpää, Petri J; Mäenpää, Heikki M

2012-09-01

380

The role of trochlear dysplasia in patellofemoral instability.  

PubMed

Trochlear dysplasia is characterized by abnormal trochlear morphology and a shallow groove. It is associated with recurrent patellar dislocation, but it is unclear whether the dysplasia is congenital, the result of lateral tracking and chronic instability, or caused by a combination of factors. Lateral radiographs elucidate the crossing sign and characteristic trochlear prominence. Recurrent patellofemoral instability is multifactorial, and each component must be considered in determining treatment. Managing other factors associated with recurrent instability may compensate for a deficient trochlea and provide stability. Medial patellofemoral ligament reconstruction is recommended for patellofemoral instability in the presence of trochlear dysplasia in patients without patella alta or increased tibial tubercle-trochlear groove distance. Trochleoplasty should be reserved for severe dysplasia in which patellofemoral stability cannot otherwise be obtained. PMID:21205763

Bollier, Matthew; Fulkerson, John P

2011-01-01

381

Modern management of patellar instability.  

PubMed

Recurrent patellofemoral instability is a disabling condition, attributed to a variety of anatomical aetiologies. Trochlear dysplasia, patella alta, an increased tibial tubercle trochlear groove distance of greater than 20 mm and soft tissue abnormalities such as a torn medial patellofemoral ligament and inadequate vastus medialis obliquus are all factors to be considered. Management of this condition remains difficult and controversial and knowledge of the functional anatomy and biomechanics of the patellofemoral joint, a detailed history and clinical examination, and an accurate patient assessment are all imperative to formulate an appropriate management plan. Surgical treatment is based on the underlying anatomical pathology with an aim to restore normal patellofemoral kinematics. We summarise aspects of assessment, treatment and outcome of patellofemoral instability and propose an algorithm of treatment. PMID:23052278

Rhee, Shin-Jae; Pavlou, George; Oakley, Jeremy; Barlow, David; Haddad, Farres

2012-12-01

382

The Elmslie-Trillat procedure for recurrent patellar subluxation after total knee arthroplasty.  

PubMed

Patellofemoral problems are the most common complications after total knee arthroplasty (TKA). We report a patient who had patellar subluxation twice within 7 months after primary TKA. Postoperative radiographs and computed tomography scans revealed a valgus knee with no evidence of malposition of the prostheses. To eliminate the recurrent patellar subluxation, we finally performed an Elmslie-Trillat procedure in combination with extensive lateral release and succeeded in achieving normal patellar tracking. At 1-year postoperative follow-up, the patient was satisfied with the results. The patella tracked well in the femoral trochlear groove during knee flexion after the revision surgery. This procedure, in combination with lateral release, should be considered as a useful surgical treatment that can eliminate patellar subluxation after TKA in cases without component malposition. PMID:20888547

Nakajima, Arata; Watanabe, Hitoshi; Rokkaku, Tomoyuki; Koda, Masao; Yamada, Toshiyuki; Murakami, Masazumi

2010-10-01

383

Valgus instability as a cause for recurrent lateral patellar dislocation: a new mechanism for patellofemoral instability?  

PubMed

An association between lateral patellar dislocation (LPD) and medial collateral ligament injury (MCL) has recently been demonstrated on MRI. The same valgus injury that disrupts the femoral MCL insertion can also cause a simultaneous MPFL tear at its femoral insertion, due to the close anatomical relationship of both ligamentous structures. Valgus laxity due to MCL-deficiency increases the Q-angle and further adversely affects patellar stability. A knee diagnosed with a severe MCL tear, should be evaluated for patellofemoral instability, as a temporary patella dislocation could have been caused by the same injury and an acute LPD indicating a tear of the MPFL can be associated with a concomitant injury of the MCL. In case of recurrent symptoms of patellofemoral instability in a MCL-deficient knee, both the MPFL and MCL should be managed operatively. An isolated MPFL reconstruction in this knee is likely to fail due to a persistent increase of the Q-angle. PMID:24350508

Hermans, Kristof; Claes, Steven; Bellemans, Johan

2013-10-01

384

The role of trochleoplasty in patellofemoral instability.  

PubMed

The management of recurrent patellofemoral instability is challenging. The etiology of the instability is multifactorial, requiring the examination of lower limb alignment, relationship of the patella to the trochlear groove and tibial tubercle, and the soft-tissue restraints. As initial surgical efforts were aimed at isolated soft-tissue repair or reconstruction, patients often had continued instability. Thus, a heightened interest in trochleoplasty has occurred as trochlear dysplasia has been found in 85% of patients with recurrent instability. Different types of trochleoplasties have been developed depending on the type of dysplasia including the trochlear lengthening osteotomy, the proximal open trochleoplasty, the deepening trochleoplasty, and the arthroscopic deepening trochleoplasty. The techniques, benefits, and results of these trochleoplasties will be presented in this review. PMID:22878658

Duncan, Stephen T; Noehren, Brian S; Lattermann, Christian

2012-09-01

385

The Role of Trochleoplasty in Patellofemoral Instability  

PubMed Central

The management of recurrent patellofemoral instability is challenging. The etiology of the instability is multifactorial, requiring the examination of lower limb alignment, relationship of the patella to the trochlear groove and tibial tubercle, and the soft-tissue restraints. As initial surgical efforts were aimed at isolated soft-tissue repair or reconstruction, patients often had continued instability. Thus, a heightened interest in trochleoplasty has occurred as trochlear dysplasia has been found in 85% of patients with recurrent instability. Different types of trochleoplasties have been developed depending on the type of dysplasia including the trochlear lengthening osteotomy, the proximal open trochleoplasty, the deepening trochleoplasty, and the arthroscopic deepening trochleoplasty. The techniques, benefits, and results of these trochleoplasties will be presented in this review. PMID:22878658

Duncan, Stephen T.; Noehren, Brian S.; Lattermann, Christian

2014-01-01

386

Severe cartilage damage of the knee joint in two young women with hypermobility.  

PubMed

The purpose of this pictorial assay is to show the arthroscopic findings of two patients with hypermobility syndrome and patellofemoral malalignment. Severe chondral damage and recurrent bleeding were common findings in these patients. One patient also had a meniscal impingement syndrome. A dynamic assessment of the patellofemoral joint as well as the evaluation of the lateral and medial retinaculum was performed by arthroscopy. Pictures of damaged area on the articular cartilage were obtained through a 5-mm arthroscope using standard portals. A lack of the patellae retinaculum involvement was proved arthroscopically in both cases. Mechanical complaints and recurrent effusion, even without history of trauma, should alert physicians who manage patients with hypermobility. In patients with joint hypermobility, the damage of the cartilage is real and often a therapeutic challenge. PMID:21881992

Checa, Angel

2012-11-01

387

Efficacy and mid term results of lateral parapatellar approach without tibial tubercle osteotomy for primary total knee arthroplasty in fixed valgus knees.  

PubMed

The lateral parapatellar approach, despite providing direct access to the pathological area has not been widely accepted for knee arthroplasty in valgus deformities. We performed a modified lateral (Keblish) approach which consisted of coronal z plasty of lateral retinaculum, quadriceps snip, titrated sequential lateral release and closure with expanded lateral structures in 32 arthritic fixed valgus knees. In 30 knees, either tendon of popliteus or lateral collateral ligament or both could be preserved. At an average follow-up of 5 years, the valgus alignment improved from 25.4° (11°-60°) to 4° (0°-10°) and knee society score improved from 34 to 95 points. There was no late instability or revisions. This approach is rational, eliminates patella maltracking, is applicable in severe deformities and with titrated release, can preserve the posterolateral knee stabilizers that are necessary for long term implant survival. PMID:23702269

Satish, Bhava R J; Ganesan, Jutty C; Chandran, Prakash; Basanagoudar, Praveen L; Balachandar, Damodharasamy

2013-12-01

388

The trivector approach for minimally invasive total knee arthroplasty: a technical note.  

PubMed

One of the main criticisms of minimally invasive approaches in total knee arthroplasty has been their poor adaptability in cases of major deformity or stiffness of the knee joint. When they are used in such cases, excessive soft-tissue tension is needed to provide appropriate joint exposure. Here, we describe the "mini trivector approach," which has become our standard approach for total knee replacement because it permits us to enlarge the indication for minimally or less invasive total knee replacement to many knees where quad sparing, a subvastus approach, or a mini quad or mini midvastus snip may not be sufficient to achieve correct exposure. It consists of a limited double snip of the VMO and the quadriceps tendon that reduces tension on the extensor mechanism and allows easier verticalization of the patella as well as good joint exposure. PMID:22527151

Benazzo, Francesco; Rossi, Stefano Marco Paolo

2012-09-01

389

Subject-specific evaluation of patellofemoral joint biomechanics during functional activity.  

PubMed

Patellofemoral joint pain is a common problem experienced by active adults. However, relatively little is known about patellofemoral joint load and its distribution across the medial and lateral facets of the patella. In this study, biomechanical experiments and computational modeling were used to study patellofemoral contact mechanics in four healthy adults during stair ambulation. Subject-specific anatomical and gait data were recorded using magnetic resonance imaging, dynamic X-ray fluoroscopy, video motion capture, and multiple force platforms. From these data, in vivo tibiofemoral joint kinematics and knee muscle forces were computed and then applied to a deformable finite-element model of the patellofemoral joint. The contact force acting on the lateral facet of the patella was 4-6 times higher than that acting on the medial facet. The peak average patellofemoral contact stresses were 8.2±1.0 MPa and 5.9±1.3 MPa for the lateral and medial patellar facets, respectively. Peak normal compressive stress and peak octahedral shear stress occurred near toe-off of the contralateral leg and were higher on the lateral facet than the medial facet; furthermore, the peak compressive stress (11.5±3.0 MPa) was higher than the peak octahedral shear stress (5.2±0.9 MPa). The dominant stress pattern on the lateral patellar facet corresponded well to the location of maximum cartilage thickness. Higher loading of the lateral facet is also consistent with the clinical observation that the lateral compartment of the patellofemoral joint is more prone to osteoarthritis than the medial compartment. Predicted cartilage contact stress maps near contralateral toe-off showed three distinctly different patterns: peak stresses located on the lateral patellar facet; peak stresses located centrally between the medial and lateral patellar facets; and peak stresses located superiorly on both the medial and lateral patellar facets. PMID:24998901

Akbarshahi, Massoud; Fernandez, Justin W; Schache, Anthony G; Pandy, Marcus G

2014-09-01

390

Prenatal Lead Exposure and Weight of 0- to 5-Year-Old Children in Mexico City  

PubMed Central

Background: Cumulative prenatal lead exposure, as measured by maternal bone lead burden, has been associated with smaller weight of offspring at birth and 1 month of age, but no study has examined whether this effect persists into early childhood. Objective: We investigated the association of perinatal maternal bone lead, a biomarker of cumulative prenatal lead exposure, with children’s attained weight over time from birth to 5 years of age. Methods: Children were weighed at birth and at several intervals up until 60 months. Maternal tibia and patella lead were measured at 1 month postpartum using in vivo K-shell X-ray fluorescence. We used varying coefficient models with random effects to assess the association of maternal bone lead with weight trajectories of 522 boys and 477 girls born between 1994 and 2005 in Mexico City. Results: After controlling for breast-feeding duration, maternal anthropometry, and sociodemographic characteristics, a 1-SD increase in maternal patella lead (micrograms per gram) was associated with a 130.9-g decrease in weight [95% confidence interval (CI), –227.4 to –34.4 g] among females and a 13.0-g nonsignificant increase in weight among males (95% CI, –73.7 to 99.9 g) at 5 years of age. These associations were similar after controlling for concurrent blood lead levels between birth and 5 years. Conclusions: Maternal bone lead was associated with lower weight over time among female but not male children up to 5 years of age. Given that the association was evident for patellar but not tibial lead levels, and was limited to females, results need to be confirmed in other studies. PMID:21715242

Peterson, Karen E.; Sanchez, Brisa N.; Cantonwine, David; Lamadrid-Figueroa, Hector; Schnaas, Lourdes; Ettinger, Adrienne S.; Hernandez-Avila, Mauricio; Hu, Howard; Tellez-Rojo, Martha M.

2011-01-01

391

Comparison of articulating and static spacers regarding infection with resistant organisms in total knee arthroplasty  

PubMed Central

Introduction The result of treatment of infections involving antibiotic-resistant organisms in total knee arthroplasty (TKA) is often poor. We evaluated the efficacy of 2-stage revision in TKAs infected with resistant organisms and compared the clinical outcomes with articulating and conventional static spacers, in terms of both infection control and function. Methods In a prospective manner, from June 2003 to January 2007 selected patients with a TKA infected with resistant organisms were enrolled and treated with 2-stage re-implantation. The 45 patients were divided into 2 groups: group A (23 patients) implanted with the articulating spacers and group S (22 patients) implanted with static spacers. All patients followed the same antibiotic protocols and had the same re-implantation criteria. The efficacy of infection control was evaluated using re-implantation rate, recurrence rate, and overall success rate. The functional and radiographic results were interpreted with the Hospital of Special Surgery (HSS) knee score and the Insall-Salvati ratio. Results With mean 40 (24–61) months of follow-up, 22 of 23 knees were re-implanted in group A and 21 of 22 were re-implanted in group S. Of these re-implanted prostheses, 1 re-infection occurred in group A and 2 occurred in group S. Range of motion after re-implantation, the final functional scores, and the satisfaction rate were better in group A. One third of the patients in group S, and none in group A, had a patella baja. Interpretation After 2-stage re-implantation of TKAs originally infected with resistant organisms, the clinical outcome was satisfactory—and similar to that reported after treatment of TKAs infected with low-virulence strains. Treatment with an articulating spacer resulted in better functional outcome and lower incidence of patella baja. PMID:21883049

2011-01-01

392

Load-dependent variations in knee kinematics measured with dynamic MRI.  

PubMed

Subtle changes in knee kinematics may substantially alter cartilage contact patterns and moment generating capacities of soft tissues. The objective of this study was to use dynamic magnetic resonance imaging (MRI) to measure the influence of the timing of quadriceps loading on in vivo tibiofemoral and patellofemoral kinematics. We tested the hypothesis that load-dependent changes in knee kinematics would alter both the finite helical axis of the tibiofemoral joint and the moment arm of the patellar tendon. Eight healthy young adults were positioned supine in a MRI-compatible device that could impose either elastic or inertial loads on the lower leg in response to cyclic knee flexion-extension. The elastic loading condition induced concentric quadriceps contractions with knee extension, while an inertial loading condition induced eccentric quadriceps contractions with knee flexion. Peak internal knee extension moments ranged from 23 to 33 N m, which is comparable to loadings seen in normal walking. We found that anterior tibia translation, superior patella glide, and anterior patella translation were reduced by an average of 5.1, 5.7 and 2.9 mm when quadriceps loading coincided with knee flexion rather than knee extension. These kinematic variations induced a distal shift in the finite helical axis of the tibiofemoral joint and a reduction in the patellar tendon moment arm. We conclude that it may be important to consider such load-dependent changes in knee kinematics when using models to ascertain soft tissue and cartilage loading during functional tasks such as gait. PMID:23806309

Westphal, Christopher J; Schmitz, Anne; Reeder, Scott B; Thelen, Darryl G

2013-08-01

393

The effect of overstuffing the patellofemoral joint on the extensor retinaculum of the knee.  

PubMed

Overstuffing the patellofemoral compartment during TKR leads to complications such as maltracking and wear, predisposing to early failure. However, there is no data describing how the patellar construct thickness affects the retinacula. This study instrumented cadaveric knees that had a Genesis II (Smith & Nephew, Memphis, TN, USA) TKR in situ. Sutures were passed along the medial patellofemoral ligament (MPFL) and the deep transverse fibre band of the lateral retinaculum, from the ilio-tibial band (ITB) to the patella. These sutures were attached to displacement transducers. Length changes in the retinacula were measured during knee flexion-extension against the actions of 175 N quadriceps and 30 N ITB tensions. This was done with the natural patellar thickness, then repeated with the patella 2 mm thinner, 2 mm thicker and 4 mm thicker (overstuffed). Each thickness change caused a significant overall slackening or stretching of the MPFL (P < 0.0001 by ANOVA), with 2.3 mm mean stretching (P < 0.001 all angles of knee flexion by post-testing) at 4 mm thicker. The ITB-patellar band was not slackened (P = 0.491) or stretched (P = 0.346) significantly by 2 mm thickness changes. 4 mm thickening stretched the lateral retinaculum 1.1 mm (P = 0.0108). Patellar thickness affected the MPFL more than the lateral retinaculum. This difference reflected the mobile attachment of the lateral retinaculum to the ITB, whereas the MPFL was stretched directly between bony attachments. 2 mm overstuffing did not stretch the retinacula sufficiently to cause mechanical effects. PMID:19526222

Ghosh, K M; Merican, A M; Iranpour, F; Deehan, D J; Amis, Andrew A

2009-10-01

394

Mid-term results with a highly congruous mobile-bearing knee prosthesis.  

PubMed

Two hundred and six consecutive total knee arthroplasties were performed in 180 patients with a highly congruous mobile-bearing knee prosthesis. At mean follow-up of 78 months (range: 60-102 months), the outcomes of 181 knees in 158 patients were evaluated using the American Knee Society's Knee and Functional scoring system and Radiological scoring system. Mean values for Knee and Function scores were 92.6 and 81.1, respectively versus 51.8 and 43.4 preoperatively; mean flexion range was 113.6 degrees versus 110.8 degrees preoperatively. There were no cases of bearing dislocation and no radiological signs of loosening or osteolysis. Secondary patella resurfacing was done in 7 of 52 knees in which the patella was not primarily resurfaced. Arthroplasty survival with revision for aseptic loosening as the endpoint was 100% (95% CI: 97.7-100) at 5 years and at 8 years (95% CI: 87.2-100); with revision of the arthroplasty for any reason including one revision for infection as the endpoint, survival was 99.5% (95% CI: 96.9-100) at 5 years and at 8 years (95% CI: 86.9-100). The overall results were satisfactory and compared with those of other mobile-bearing knee prostheses featuring full or partial congruence. No significant differences were noted for range of motion, knee scores and function scores between two subsets of knees that received a bearing allowing only rotation or rotation and 5 mm anteroposterior translation. Longer follow-up is needed to evaluate possible benefits of high congruence and of specific modes of bearing mobility with respect to wear and bony fixation. PMID:19701626

Lemaire, Roger G

2010-02-01

395

[Ligament instability in total knee arthroplasty--causal analysis].  

PubMed

Ligament instability is a common reason for revision total knee arthroplasty (TKA). A meticulous analysis of the type of instability is very important in order to revise such a knee successfully. The objective of this study was to analyze the different reasons for ligament instability in revision TKA. A total of 135 knee revisions performed by one surgeon were analyzed pre- (clinical and x-ray) and intraoperatively for the cause of failure. X-ray analysis included the assessment of each component for position. Intraopertive analysis included stability testing in extension and 30 degrees , and 90 degrees of flexion, wear pattern, patella motion (shifting and tilting) and patella height. In 32.6 % of all cases, ligament instability was the primary reason for revision. In another 21.6%, ligament instability was identified as a secondary reason for revision. Analysis of the different instability forms showed combined instability in extension and flexion as the most common cause, followed by isolated instability in flexion (31.8%) and isolated instability in extension (9.1%). The high correlation between instability and malpositioning of the prostheses was obvious. Often, an isolated femoral malposition, in particular for rotation, was found, as well as an isolated malposition of the tibia component. In summary, ligament instability is a common reason for revision TKA. Many different forms of instability can be found either as isolated or combined instability types. Correct anatomical positioning of the components and balanced ligaments in the different extension and flexion positions are important for good clinical results, a stable joint, good function and longevity. PMID:17581739

Graichen, H; Strauch, M; Katzhammer, T; Zichner, L; von Eisenhart-Rothe, R

2007-07-01

396

Influence of Prenatal Lead Exposure on Genomic Methylation of Cord Blood DNA  

PubMed Central

Background Fetal lead exposure is associated with adverse pregnancy outcomes and developmental and cognitive deficits; however, the mechanism(s) by which lead-induced toxicity occurs remains unknown. Epigenetic fetal programming via DNA methylation may provide a pathway by which environmental lead exposure can influence disease susceptibility. Objective This study was designed to determine whether prenatal lead exposure is associated with alterations in genomic methylation of leukocyte DNA levels from umbilical cord samples. Methods We measured genomic DNA methylation, as assessed by Alu and LINE-1 (long interspersed nuclear element-1) methylation via pyrosequencing, on 103 umbilical cord blood samples from the biorepository of the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) study group. Prenatal lead exposure had been assessed by measuring maternal bone lead levels at the mid-tibial shaft and the patella using a spot-source 109Cd K-shell X-ray fluorescence instrument. Results We found an inverse dose–response relationship in which quartiles of patella lead correlated with cord LINE-1 methylation (p for trend = 0.01) and and tibia lead correlated with Alu methylation (p for trend = 0.05). In mixed effects regression models, maternal tibia lead was negatively associated with umbilical cord genomic DNA methylation of Alu (?= ?0.027; p = 0.01). We found no associations between cord blood lead and cord genomic DNA methylation. Conclusions Prenatal lead exposure is inversely associated with genomic DNA methylation in cord blood. These data suggest that the epigenome of the developing fetus can be influenced by maternal cumulative lead burden, which may influence long-term epigenetic programming and disease susceptibility throughout the life course. PMID:19750115

Pilsner, J. Richard; Hu, Howard; Ettinger, Adrienne; Sanchez, Brisa N.; Wright, Robert O.; Cantonwine, David; Lazarus, Alicia; Lamadrid-Figueroa, Hector; Mercado-Garcia, Adriana; Tellez-Rojo, Martha Maria; Hernandez-Avila, Mauricio

2009-01-01

397

The manipulation of strain, when stress is controlled, modulates in vivo tendon mechanical properties but not systemic TGF-?1 levels  

PubMed Central

Modulators of loading-induced in vivo adaptations in muscle–tendon complex (MTC) mechanical properties remain unclear. Similarly contentious, is whether changes in MTC characteristics are associated with growth factor levels. Four groups were subjected to varying magnitudes of stress/strain: Group 1 trained with the MTC at a shortened position (MTCS; n = 10); Group 2 at a lengthened position (MTCL; n = 11; stress levels matched to MTCS); Group 3 over a wide range of motion (MTCX; n = 11); and Group 4 (n = 10) was the control population (no training). Patella tendon Stiffness (P < 0.001), Young's modulus, and quadriceps torque (P < 0.05) increments (only seen in the training groups), showed MTCL and MTCX groups responses to be superior to those of MTCS (P < 0.05). In addition, MTCL and MTCX better maintained adaptations compared to MTCS (P < 0.05) following detraining, with a pattern of slower loss of improvements at the early phase of detraining in all training groups. There were no significant changes (P > 0.05) in antagonist cocontraction, patella tendon dimensions or circulating transforming growth factor beta (TGF-?1) levels following training or detraining in any of the groups. We conclude that chronically loading the MTC in a relatively lengthened position (which involves greater strains) enhances its mechanical properties, more so than loading in a shortened position. This is true even after normalizing for internal stress. The underlying endocrine mechanisms do not appear to be mediated via TGF-?1, at least not at the systemic level. Our findings have implications with regard to the effectiveness of eccentric loading on improved tendon structural and mechanical properties. PMID:24303165

McMahon, Gerard E; Morse, Christopher I; Burden, Adrian; Winwood, Keith; Onambele-Pearson, Gladys L

2013-01-01

398

Anterior Knee Pain in Patients with Cerebral Palsy  

PubMed Central

Background The aim of this study was to identify the risk factors for anterior knee pain in patients with cerebral palsy. Methods This prospective study investigated the risk factors for anterior knee pain in 127 ambulatory patients with spastic cerebral palsy in terms of walking pain, resting pain, and provocative pain. Demographic data analysis and physical examination for measuring the knee flexion contracture and unilateral and bilateral popliteal angles were performed. Patellar height was measured on radiographs, and patella alta was identified. The risk factors for anterior knee pain were analyzed using multivariate analysis with a generalized estimating equation. Results Seventy-seven patients were found to have patella alta based on the radiographic measurements (60.6%). Overall, sixteen patients (12.6%) had either unilateral or bilateral anterior knee pain. Of these, 6 patients showed a visual analogue scale (VAS) ? 3, 9 patients showed 3 < VAS ? 7, and one patient showed a VAS > 7. Age was found to be a significant risk factor for walking pain and resting pain with odds ratios (ORs) of 1.08 (95% confidence interval [CI], 1.02 to 1.14) and 1.09 (95% CI, 1.03 to 1.15), respectively. In the multivariate analysis, knee flexion contracture was a significant protective factor with an OR of 0.92 (95% CI, 0.85 to 0.98). Conclusions Approximately 12.6% of ambulatory patients with spastic cerebral palsy were found to have anterior knee pain in our hospital-based cohort study. Age was found to be a significant risk factor for anterior knee pain while walking and resting.

Choi, Young; Lee, Sang Hyeong; Chung, Chin Youb; Park, Moon Seok; Lee, Kyoung Min; Sung, Ki Hyuk; Won, Sung Hun; Lee, In Hyeok; Choi, In Ho; Cho, Tae-Joon; Yoo, Won Joon

2014-01-01

399

Paleolithic hominin remains from Eshkaft-e Gavi (southern Zagros Mountains, Iran): description, affinities, and evidence for butchery.  

PubMed

Eshkaft-e Gavi is a cave located in the southern Zagros Mountains of Iran and is one of the few archaeological sites in the region to preserve both Middle Paleolithic and Upper Paleolithic occupations. Excavation of the site in the 1970s yielded an assemblage of lithic and faunal remains, including ten hominin specimens: a mandibular molar, four cranial fragments, a clavicular diaphysis, the proximal half of a metacarpal, a fragment of os coxa, the proximal diaphysis of a juvenile femur, and a patella. The bones derive from a minimum of four individuals, including two juveniles. Although many of these remains could be Epi-Paleolithic in age, one of the juvenile specimens-the mandibular molar-occurs at the base of the cave's Upper Paleolithic sequence. The remains are very fragmentary, but those that preserve diagnostic morphology indicate that they represent modern humans. The molar is taxonomically diagnostic, thus confirming the association of the Aurignacian-like Baradostian Industry with modern humans. Four of the specimens-a piece of frontal bone, the clavicle, the juvenile femur, and the patella-display clear evidence for intentional butchery in the form of stone-tool cutmarks. These cutmarked specimens, along with a fragment of parietal bone, are also burned. Although this evidence is consistent with cannibalism, the small sample makes it difficult to say whether or not the individuals represented by the hominin remains were butchered and cooked for consumption. Nevertheless, the cutmarked Eshkaft-e Gavi specimens add to a growing sample of hominin remains extending back into the Plio-Pleistocene that display evidence of intentional defleshing. PMID:19660782

Scott, Jeremiah E; Marean, Curtis W

2009-09-01

400

Extra articular arthroscopic release in post-traumatic stiff knees: a prospective study of endoscopic quadriceps and patellar release.  

PubMed

Knee stiffness due to mismanaged trauma is still common in underdeveloped countries. Many patients with distal femoral fractures, patellar injuries or other local trauma present with intra-articular and extra-articular adhesions between the quadriceps and anterior femur. Nineteen knees with post trauma stiffness due to combined intra- and extra- articular aetiology were taken up for arthroscopic aided release after failing an aggressive physiotherapy protocol. Ultrasound was used to identify the extra-articular adhesions. The intra-articular part of the release was done by a standard protocol involving the release of all infrapatellar, suprapatellar and gutter adhesions, and then the extra-articular proximal adhesions were released by using special long periosteal elevators and arthroscopic scissors. We were able to release the adhesions as high as 9 inches above the patella, and in one case bony ankylosis between the patella and the femur was arthroscopically osteotomised (after 11 years of stiffness). Delay before surgery averaged 2.7 years (6 months-11.3 years). Mean active flexion at one year follow-up improved from 27.3 degrees to 119.3 degrees (average increase: 92 degrees). Mean preoperative extension lag reduced from 6 degrees to 1 degrees postoperatively. No CPM machine was available, and patients had to undergo daily manual and assisted therapy, with appropriate analgesia. Overall patient satisfaction was excellent; one patient developed a supracondylar fracture (infected old fracture with bone loss and severe contracture) and was retrospectively a wrong case selection. Arthroscopic aided quadriceps adhesion release is a good option in cases of neglected trauma; results are excellent even without sophisticated CPM machines, and the periosteal elevators needed are cheap and indigenous. PMID:16152854

Dhillon, Mandeep S; Panday, Awadesh K; Aggarwal, Sameer; Nagi, Onkar N

2005-04-01

401

Southwick-Fulkerson Osteotomy with Intraoperative Femoral Nerve Guidance  

PubMed Central

Background Patellofemoral instability is a complex problem with most previous treatment plans addressing static alignment and static stabilizers. Although the quadriceps muscles are known to affect the tracking of the patella, they are rarely taken into account during a surgical procedure. Purpose The purpose of this study is to determine the two year minimum results of 37 knees which received a Southwick-Fulkerson Osteotomy and MPFL repair or reconstruction both under the guidance of femoral nerve stimulation Methods Patients underwent a Southwick-Fulk- erson Osteotomy and either medial patellofemoral ligament (MPFL) repair or reconstruction using femoral nerve stimulation as a means of dynamic intraoperative evaluation of patello-femoral con- gruity in terminal extension. Two year minimum outcomes of 26 patients, 31 knees (84% return rate) were evaluated using KOOS and IKDC scores, and physical exam features of apprehension and assessment of dynamic tracking in the last 30 degrees of knee extension. Variables were evaluated with t-tests and ANOVA. Results 29/31 knees reported they were happy with the procedure and reported they would do it again. One knee (3%) reportedly “redislocated”, but did not return for verification by exam. 30/31 had non-pathologic tracking. One knee displayed a small but residual J sign. 4/16 knees with MPFL repair only and 0/15 with MPFL repair and reconstruction exhibited a positive apprehension sign. Increased age and apprehension were correlated with lower outcome scores. Conclusions Intraoperative femoral nerve stimulation is an effective way of evaluating patellar tracking intraoperatively that leads to 97% stable patellae with near congruent patello-femoral tracking. MPFL reconstruction is superior to MPFL repair in eliminating the persistence of the apprehension sign. PMID:24027467

Mellecker, Scott; Ebinger, Thomas; Butler, Paul; Albright, John

2013-01-01

402

Does form follow function in trochlear dysplasia? Case report of patellar instability in a below-knee amputee?  

PubMed Central

INTRODUCTION Patellar instability can be considered as a rapidly increasing musculoskeletal subject of interest. It is now well accepted that multiple factors can produce this pathological condition, isolated, but more often in concert. One major static compound is found to be in trochlear dysplasia. It has been stated that the form of the trochlear surface is primary and genetically bilaterally determined already before use. According to these data, recurrent dislocation of the patella has been described as a hereditary disease with autosomal dominant transmission. Against this assumption, we hypothesize that subjects may devise a flattened trochlea when there is no significant biomechanical interplay and thus input between the patella and the distal femur during developmental growth; according to the assumption form follows function. PRESENTATION OF CASE In this context, we report the case of a 16-year old male who previously suffered from a traumatic patellar dislocation during sporting activity in his below-knee amputated lower extremity, which occured at age of 18 months. The patient was allocated with a high-grade trochlear dysplasia in his previously amputated limb, while presenting a normal trochlear shape at his healthy contralateral leg. DISCUSSION This rare case therefore reprents the history of an individuum with identic genetic predisposition and different biomechanical influences during childhood, which makes it of high clinical interest. In presence of trochlear dysplasia the patient suffered reluxation and concurrent subjective instability on the lower limb affected by the amputation which was treated with medial patellofemoral ligament (MPFL) plasty using an autologous gracilis graft. CONCLUSION One has to consider that a certain biomechanical input may be required for the development of a physiologic trochlear groove. PMID:24441714

Salzmann, Gian M.; Dovi-Akue, David; Watzig, Klaus; Sudkamp, Norbert P.; Niemeyer, Philipp

2013-01-01

403

Medial patellofemoral ligament (MPFL) reconstruction for the treatment of patellofemoral instability.  

PubMed

Patellofemoral instability can be a disabling problem. Numerous techniques are employed for its treatment. Medial patellofemoral ligament (MPFL) reconstruction in combination with other procedures has been explored by many orthopedic surgeons. The purpose of the study was to determine the effectiveness of isolated MPFL reconstruction in treating the symptoms associated with patellofemoral instability, preventing recurrence of patella dislocation, and returning patients to preinjury level of activity. This is a case series study. We conducted a clinical follow-up study on 56 knees (49 patients) after MPFL reconstruction for recurrent patellar instability with a mean follow-up of 4.3 years (range, 1.1-6.8). A single MPFL reconstruction technique was performed in all cases. Patient outcomes were evaluated using: International Knee Documentation Committee (IKDC) subjective knee form, Tegner activity score, functional hop test, and radiographs. Mean age at time of surgery was 24 years old (range, 13-49). Females comprised 75% of the sample. Mean interval from injury to surgery was 7.2?±?8.6 years (range, 51 days-37 years). At follow-up, there were no recurrent dislocations reported, patella subluxation in 6 (11%) cases, and radiographic degenerative changes were none to mild in all patients. The series mean IKDC scores at follow-up was 76.3?±?19.2 (range, 30-99), and Tegner activity scores were 5.6?±?2.5. MPFL reconstruction is an option for treating the symptoms of patellar instability, preventing recurrent dislocation, and returning patients near to their preinjury level of activity. The level of evidence is IV. PMID:24227396

Csintalan, Rick P; Latt, L Daniel; Fornalski, Stefan; Raiszadeh, Kian; Inacio, Maria Cs; Fithian, Donald C

2014-04-01

404

The controversy of patellar resurfacing in total knee arthroplasty: Ibisne in medio tutissimus?  

PubMed

Early arthroplasty designs were associated with a high level of anterior knee pain as they failed to cater for the patello-femoral joint. Patellar resurfacing was heralded as the saviour safeguarding patient satisfaction and success but opinion on its necessity has since deeply divided the scientific community and has become synonymous to topics of religion or politics. Opponents of resurfacing contend that the native patella provides better patellar tracking, improved clinical function, and avoids implant-related complications, whilst proponents argue that patients have less pain, are overall more satisfied, and avert the need for secondary resurfacing. The question remains whether complications associated with patellar resurfacing including those arising from future component revision outweigh the somewhat increased incidence of anterior knee pain recorded in unresurfaced patients. The current scientific literature, which is often affected by methodological limitations and observer bias, remains confusing as it provides evidence in support of both sides of the argument, whilst blinded satisfaction studies comparing resurfaced and non-resurfaced knees generally reveal equivalent results. Even national arthroplasty register data show wide variations in the proportion of patellar resurfacing between countries that cannot be explained by cultural differences alone. Advocates who always resurface or never resurface indiscriminately expose the patella to a random choice. Selective resurfacing offers a compromise by providing a decision algorithm based on a propensity for improved clinical success, whilst avoiding potential complications associated with unnecessary resurfacing. Evidence regarding the validity of selection criteria, however, is missing, and the decision when to resurface is often based on intuitive reasoning. Our lack of understanding why, irrespective of pre-operative symptoms and patellar resurfacing, some patients may suffer pain following TKA and others may not have so far stifled our efforts to make the strategy of selective resurfacing succeed. We should hence devote our efforts in defining predictive criteria and indicators that will enable us to reliably identify those individuals who might benefit from a resurfacing procedure. Level of evidence V. PMID:22484417

Schindler, Oliver S

2012-07-01

405

Levels of lead in breast milk and their relation to maternal blood and bone lead levels at one month postpartum.  

PubMed Central

Despite the many well-recognized benefits of breast-feeding for both mothers and infants, detectable levels of lead in breast milk have been documented in population studies of women with no current environmental or occupational exposures. Mobilization of maternal bone lead stores has been suggested as a potential endogenous source of lead in breast milk. We measured lead in breast milk to quantify the relation between maternal blood and bone lead levels and breast-feeding status (exclusive vs. partial) among 310 lactating women in Mexico City, Mexico, at 1 month postpartum. Umbilical cord and maternal blood samples were collected at delivery. Maternal breast milk, blood, and bone lead levels were obtained at 1 month postpartum. Levels of lead in breast milk ranged from 0.21 to 8.02 microg/L (ppb), with a geometric mean (GM) of 1.1 microg/L; blood lead ranged from 1.8 to 29.9 microg/dL (GM = 8.4 microg/dL); bone lead ranged from < 1 to 67.2 microg/g bone mineral (patella) and from < 1 to 76.6 microg/g bone mineral (tibia) at 1 month postpartum. Breast milk lead was significantly correlated with umbilical cord lead [Spearman correlation coefficient (rS) = 0.36, p < 0.0001] and maternal blood lead (rS= 0.38, p < 0.0001) at delivery and with maternal blood lead (rS = 0.42, p < 0.0001) and patella lead (rS= 0.15, p < 0.01) at 1 month postpartum. Mother's age, years living in Mexico City, and use of lead-glazed ceramics, all predictive of cumulative lead exposure, were not significant predictors of breast milk lead levels. Adjusting for parity, daily dietary calcium intake (milligrams), infant weight change (grams), and breast-feeding status (exclusive or partial lactation), the estimated effect of an interquartile range (IQR) increase in blood lead (5.0 microg/dL) was associated with a 33% increase in breast milk lead [95% confidence interval (CI), 24 to 43%], whereas an IQR increase in patella lead (20 microg/g) was associated with a 14% increase in breast milk lead (95% CI, 5 to 25%). An IQR increase in tibia lead (12.0 microg/g) was associated with a 5% increase in breast milk lead (95% CI, -3% to 14%). Our results indicate that even among a population of women with relatively high lifetime exposure to lead, levels of lead in breast milk are low, influenced both by current lead exposure and by redistribution of bone lead accumulated from past environmental exposures. PMID:15175184

Ettinger, Adrienne S; Tellez-Rojo, Martha Maria; Amarasiriwardena, Chitra; Gonzalez-Cossio, Teresa; Peterson, Karen E; Aro, Antonio; Hu, Howard; Hernandez-Avila, Mauricio

2004-01-01

406

The TOPGAME-study: effectiveness of extracorporeal shockwave therapy in jumping athletes with patellar tendinopathy. Design of a randomised controlled trial  

PubMed Central

Background Patellar tendinopathy is a major problem for many athletes, especially those involved in jumping activities. Despite its frequency and negative impact on athletic careers, no evidence-based guidelines for management of this overuse injury exist. Since functional outcomes of conservative and surgical treatments remain suboptimal, new diagnostic and therapeutic strategies have to be developed and evaluated. Extracorporeal shockwave therapy (ESWT) appears to be a promising treatment in patients with chronic patellar tendinopathy. ESWT is most often applied after the known conservative treatments have failed. However, its effectiveness as primary therapy has not been studied in athletes who keep playing sports despite having patellar tendon pain. The aim of this study is to determine the effectiveness of ESWT in athletes with patellar tendinopathy who are still in training and competition. Methods/design The TOPGAME-study (Tendinopathy of Patella Groningen Amsterdam Maastricht ESWT) is a multicentre two-armed randomised controlled trial with blinded participants and outcome assessors, in which the effectiveness of patient-guided focussed ESWT treatment (compared to placebo ESWT) on pain reduction and recovery of function in athletes with patellar tendinopathy will be investigated. Participants are volleyball, handball and basketball players with symptoms of patellar tendinopathy for a minimum of 3 to a maximum duration of 12 months who are still able to train and compete. The intervention group receives three patient-guided focussed medium-energy density ESWT treatments without local anaesthesia at a weekly interval in the first half of the competition. The control group receives placebo treatment. The follow-up measurements take place 1, 12 and 22 weeks after the final ESWT or placebo treatment, when athletes are still in competition. Primary outcome measure is the VISA-P (Victorian Institute of Sport Assessment - patella) score. Data with regard to pain during function tests (jump tests and single-leg decline squat) and ultrasound characteristics are also collected. During the follow-up period participants also register pain, symptoms, sports participation, side effects of treatment and additional medical consumption in an internet-based diary. Discussion The TOPGAME-study is the first RCT to study the effectiveness of patient-guided ESWT in athletes with patellar tendinopathy who are still in training and competition. Trial registration Trial registration number NTR1408. PMID:20144188

2010-01-01

407

Simultaneous segmentation of the bone and cartilage surfaces of a knee joint in 3D  

NASA Astrophysics Data System (ADS)

We present a novel framework for the simultaneous segmentation of multiple interacting surfaces belonging to multiple mutually interacting objects. The method is a non-trivial extension of our previously reported optimal multi-surface segmentation. Considering an example application of knee-cartilage segmentation, the framework consists of the following main steps: 1) Shape model construction: Building a mean shape for each bone of the joint (femur, tibia, patella) from interactively segmented volumetric datasets. Using the resulting mean-shape model - identification of cartilage, non-cartilage, and transition areas on the mean-shape bone model surfaces. 2) Presegmentation: Employment of iterative optimal surface detection method to achieve approximate segmentation of individual bone surfaces. 3) Cross-object surface mapping: Detection of inter-bone equidistant separating sheets to help identify corresponding vertex pairs for all interacting surfaces. 4) Multi-object, multi-surface graph construction and final segmentation: Construction of a single multi-bone, multi-surface graph so that two surfaces (bone and cartilage) with zero and non-zero intervening distances can be detected for each bone of the joint, according to whether or not cartilage can be locally absent or present on the bone. To define inter-object relationships, corresponding vertex pairs identified using the separating sheets were interlinked in the graph. The graph optimization algorithm acted on the entire multiobject, multi-surface graph to yield a globally optimal solution. The segmentation framework was tested on 16 MR-DESS knee-joint datasets from the Osteoarthritis Initiative database. The average signed surface positioning error for the 6 detected surfaces ranged from 0.00 to 0.12 mm. When independently initialized, the signed reproducibility error of bone and cartilage segmentation ranged from 0.00 to 0.26 mm. The results showed that this framework provides robust, accurate, and reproducible segmentation of the knee joint bone and cartilage surfaces of the femur, tibia, and patella. As a general segmentation tool, the developed framework can be applied to a broad range of multi-object segmentation problems.

Yin, Y.; Zhang, X.; Anderson, D. D.; Brown, T. D.; Hofwegen, C. Van; Sonka, M.

2009-02-01

408

Below Knee Impact Responses using Cadaveric Specimens.  

PubMed

Knee injuries represent about 10% of all injuries suffered during car crashes. Efforts to assess the injury risk to the posterior cruciate ligament (PCL) have been based on a study available in the literature (Viano et al., 1978), in which only two of the five knees tested had PCL ruptures. The aims of the current study were to repeat the study with a higher number of samples, study the effects of other soft tissues on knee response, and assess the adequacy of the experimental setup for the identification of a PCL tolerance. A total of 14 knees were tested using a high-speed materials testing machine. Eight were intact knees (with the patella and all the muscular and ligamentous structures), three were PCL-only knees (patella and all the muscular and ligamentous structures other than the PCL removed), and the last three were PCL-only knees with the tibia protected from bending fracture. Of the eight intact knees tested, only one had PCL mid substance rupture, one had a partial articular fracture of the tibia below the plateau, and six had simple transverse fracture of the tibial metaphysis. Of the three PCL-only knees without tibial protection, one had PCL mid substance rupture, one had avulsion at the posterior intercondylar attachment point, and the last one had a simple oblique fracture of the tibial metaphysis. Of the three PCL only knees with tibia protection, two had PCL mid-substance ruptures and the third one had an avulsion at the tibial insertion site with partial articular fracture of the lateral plateau. Overall, the results of the current study were similar to those observed by Viano et al. (1978). The average displacement at failure for all PCL related injuries was 17.2+/-2.8 mm for the current study (n=6) and 16.2+/-3.9 mm for Viano et al. (1978) (n=4). This value is higher than the Injury Assessment Reference Value of 15 mm proposed by Mertz (1984) and used in various regulations. Both studies suggest that the existence of the soft tissues other than the PCL affect the injury outcome and that the intact knee would suffer predominantly tibial metaphyseal fractures possibly due to bending. Consequently, it is concluded that the current experimental setup can produce isolated PCL injuries but the data available are inadequate to characterize PCL tolerance. A Hybrid III knee equipped with a ball bearing knee slider was also tested using a pendulum setup. Apart from the initial higher stiffness, the overall response of this knee lies within the force-deflection corridors defined using the response of the cadaver knees with PCL mid-substance failure. PMID:17230262

Balasubramanian, Sriram; Beillas, Philippe; Belwadi, Aditya; Hardy, Warren N; Yang, King H; King, Albert I; Masuda, Mitsutoshi

2004-11-01

409

New intermediate phenotype between MED and DD caused by compound heterozygous mutations in the DTDST gene.  

PubMed

DTDST mutations cause a spectrum of diastrophic dysplasia disorders characterized by defects of proteoglycans sulfation. Reduction of sulfate/chloride antiporter activity is manifested by lower sulfate uptake and depends on a combination of mutations in DTDST. We analyzed a family with an autosomal recessive form of bone dysplasia. Three affected brothers from this family are compound heterozygotes for C653S/A715V mutations. We classified their phenotype as a new intermediate form between diastrophic dysplasia and multiple epiphyseal dysplasia, manifested by shortening of stature, metatarsus adductus/club foot, mild brachydactyly, proximally placed thumbs and clinodactyly of the fifth fingers. Radiographs document platyspondyly most marked in the lower thoracic and upper lumbar spine, epiphyseal dysplasia affecting predominantly the femoral heads, widening of the metaphyses, narrow growth cartilage and multilayered patellae. Exaggerated lesser trochanters of femur, that is, "monkey wrench" sign, elevated greater trochanters, thin upper pubic rami, grossly normal carpal/tarsal bones and severe, early onset osteoarthritis were other notable features. PMID:21077204

Czarny-Ratajczak, Malwina; Bieganski, Tadeusz; Rogala, Piotr; Glowacki, Maciej; Trzeciak, Tomasz; Kozlowski, Kazimierz

2010-12-01

410

Inverse relationship of the anterolateral and anteromedial thigh flap perforator anatomy.  

PubMed

Background?When anterolateral thigh (ALT) perforators are inadequate, exploration of the contralateral thigh or a new flap may be required. If the anteromedial thigh (AMT) perforators were useable in these instances, harvest could proceed from a single donor site. The purposes of this study were to define the AMT perforator anatomy and examine the relationships between the AMT and ALT perforators. Methods?A total of 100 consecutive thighs were explored. The ALT and AMT perforator size and number were documented. The relationship between ALT and AMT size and number was examined using Fisher exact test, logistic regression, and linear regression. Results?The main blood supply to the AMT flap was the rectus femoris branch (RFB) off the descending branch of the lateral circumflex femoris artery. AMT perforators were only present in 51% of the thighs and most likely a single perforator near the midpoint and 3.2 cm medial to the line connecting the anterior superior iliac spine and the patella (perforator B location). Patients with one or fewer ALT perforators had fourfold increased chance of an AMT perforator. Patients with small or no ALT perforators usually had a large AMT perforator. After assigning numeric values to perforators based on size, lower ALT perforator scores were significantly related to higher AMT scores. Conclusion?The RFB is the main vascular pedicle of the AMT flap. There is an inverse relationship between size and number of ALT and AMT perforators: when ALT perforators are inadequate, AMT perforators are typically useable. PMID:24995393

Yu, Peirong

2014-09-01

411

Characterization of microgravity effects on bone structure and strength using fractal analysis  

NASA Technical Reports Server (NTRS)

The effect of micro-gravity on the musculoskeletal system has been well studied. Significant changes in bone and muscle have been shown after long term space flight. Similar changes have been demonstrated due to bed rest. Bone demineralization is particularly profound in weight bearing bones. Much of the current techniques to monitor bone condition use bone mass measurements. However, bone mass measurements are not reliable to distinguish Osteoporotic and Normal subjects. It has been shown that the overlap between normals and osteoporosis is found for all of the bone mass measurement technologies: single and dual photon absorptiometry, quantitative computed tomography and direct measurement of bone area/volume on biopsy as well as radiogrammetry. A similar discordance is noted in the fact that it has not been regularly possible to find the expected correlation between severity of osteoporosis and degree of bone loss. Structural parameters such as trabecular connectivity have been proposed as features for assessing bone conditions. In this report, we use fractal analysis to characterize bone structure. We show that the fractal dimension computed with MRI images and X-Ray images of the patella are the same. Preliminary experimental results show that the fractal dimension computed from MRI images of vertebrae of human subjects before bedrest is higher than during bedrest.

Acharya, Raj S.; Shackelford, Linda

1995-01-01

412

A biomechanical evaluation of hinged total knee replacement prostheses.  

PubMed

The number of total knee replacements being performed worldwide is undergoing an unprecedented increase. Hinged total knee replacements, used in complex salvage and revision procedures, currently account for a small but growing proportion of prostheses implanted. Modern hinged prostheses share the same basic configuration, allowing flexion-extension and tibial rotation. One aspect on which designs differ is the anteroposterior location of the hinge. A more posterior hinge is designed to increase the patellar tendon moment arm, reducing the quadriceps force required for a given activity and benefiting the patient. Five commonly used total knee replacements were evaluated in terms of quadriceps force and patellar tendon moment arm using a laboratory-based rig. Significant differences were identified between the five prostheses in quadriceps force and patellar tendon moment arm. Analysis of the correlation between these two parameters indicates that while patellar tendon moment arm influences quadriceps force, it is not the only factor. Also important is the lever function of the patella, and it is suggested here that the non-physiological nature of the prosthetic patellofemoral geometry may result in unnatural joint function. Thus, a thorough understanding of the resulting kinematic function of hinged total knee replacements is becoming increasingly important in complex revision total knee replacement to meet rising patient expectations and functional demands. PMID:23722496

Long, Robin; Gheduzzi, Sabina; Bucher, Thomas A; Toms, Andrew D; Miles, Anthony W

2013-08-01

413

Arthroscopic treatment of chronic patellar tendinopathy in high-level athletes  

PubMed Central

Summary To present the results of arthroscopic treatment of patellar tendinopathy in high-level competition athletes. Eleven high-level athletes presented chronic patellar tendinopathy which did not respond to long term conservative treatment. Average age of the patients was 24.8 ±3.4 years old. All patients received an arthroscopic procedure with osteoplasty of the distal patellar pole, debridement of the underlying Hoffa fat pad and of the degenerated areas of the proximal posterior patella tendon and cauterization of the visible neo-vessels. Mean duration of follow-up was 17.4±4 months. Patients showed a major improvement in the Lysholm score from 49.9±5.2 to 92.5±7 and in the VISA P score from 41.2±5.2 to 86.8±14.9 on tenth post-operative week. All patients had returned to sports activities by the twelfth postoperative week. Arthroscopic treatment of chronic patellar tendinopathy found to be a minimal invasive and safe technique which produced satisfactory results. PMID:23738308

Alaseirlis, Dimosthenis Artemis; Konstantinidis, George Athanasios; Malliaropoulos, Nikolaos; Nakou, Lamprini Stefanos; Korompilias, Anastasios; Maffulli, Nicola

2012-01-01

414

Arthroscopic treatment of chronic patellar tendinopathy in high-level athletes.  

PubMed

To present the results of arthroscopic treatment of patellar tendinopathy in high-level competition athletes. Eleven high-level athletes presented chronic patellar tendinopathy which did not respond to long term conservative treatment. Average age of the patients was 24.8 ±3.4 years old. All patients received an arthroscopic procedure with osteoplasty of the distal patellar pole, debridement of the underlying Hoffa fat pad and of the degenerated areas of the proximal posterior patella tendon and cauterization of the visible neo-vessels. Mean duration of follow-up was 17.4±4 months. Patients showed a major improvement in the Lysholm score from 49.9±5.2 to 92.5±7 and in the VISA P score from 41.2±5.2 to 86.8±14.9 on tenth post-operative week. All patients had returned to sports activities by the twelfth postoperative week. Arthroscopic treatment of chronic patellar tendinopathy found to be a minimal invasive and safe technique which produced satisfactory results. PMID:23738308

Alaseirlis, Dimosthenis Artemis; Konstantinidis, George Athanasios; Malliaropoulos, Nikolaos; Nakou, Lamprini Stefanos; Korompilias, Anastasios; Maffulli, Nicola

2012-10-01

415

Anterior Cruciate Ligament Reconstruction in Patients with Generalized Joint Laxity  

PubMed Central

Generalized joint laxity is a genetically determined component of overall joint flexibility. The incidence of joint laxity in the overall population is approximately 5% to 20%, and its prevalence is higher in females. Recently it was noticed that individuals with generalized joint laxity are not only prone to anterior cruciate ligament injuries but also have inferior results after a reconstruction. Therefore, an anterior cruciate ligament reconstruction in patients with generalized laxity should be undertaken with caution due to the higher expected failure rate from the complexity of problems associated with this condition. It is also necessary to identify the risk factors for the injury as well as for the post operative outcome in this population. A criterion that includes all the associated components is necessary for the proper screening of individuals for generalized joint laxity. Graft selection for an anterior cruciate reconstruction in patients with ligament laxity is a challenge. According to the senior author, a hamstring autograft is an inferior choice and a double bundle reconstruction with a quadriceps tendon-bone autograft yields better results than a single bundle bone-patella tendon-bone autograft. Future studies comparing the different grafts available might be needed to determine the preferred graft for this subset of patients. Improved results after an anterior cruciate ligament reconstruction can be achieved by proper planning and careful attention to each step beginning from the clinical examination to the postoperative rehabilitation. PMID:20808583

Kim, Sung-Jae; Kumar, Praveen

2010-01-01

416

Porous tantalum in reconstructive surgery of the knee: a review.  

PubMed

Porous tantalum represents an alternative metal for primary and revision total knee arthroplasty (TKA) with several unique properties. Tantalum is a transition metal, which in its bulk form has shown excellent biocompatibility and is safe to use in vivo as evidenced by its current application in pacemaker electrodes, cranioplasty plates, and as radiopaque markers. Current designs for orthopedic implants maintain a high volumetric porosity (70%-80%), low modulus of elasticity (3 MPa), and high frictional characteristics, making this metal conducive to biologic fixation. The low modulus of elasticity of such components allows for more physiologic load transfer and relative preservation of bone stock. Its more bioactive nature and ingrowth properties have led to its use in primary as well as revision knee components with good early clinical results reported. In revision arthroplasty, it has been used as a structural bone graft substitute. Formation of a bone-like apatite coating in vivo affords strong fibrous ingrowth properties and allows for substantial soft-tissue attachment with the potential for use in cases such as mega-prostheses and patella salvage. Although porous tantalum is in its early stages of evolution, the initial clinical data and basic science studies support its use as an alternative to traditional orthopedic implant materials. PMID:17665779

Levine, Brett; Sporer, Scott; Della Valle, Craig J; Jacobs, Joshua J; Paprosky, Wayne

2007-07-01

417

Hip Abduction Can Prevent Posterior Edge Loading of Hip Replacements  

PubMed Central

Edge loading causes clinical problems for hard-on-hard hip replacements, and edge loading wear scars are present on the majority of retrieved components. We asked the question: are the lines of action of hip joint muscles such that edge loading can occur in a well-designed, well-positioned acetabular cup? A musculoskeletal model, based on cadaveric lower limb geometry, was used to calculate for each muscle, in every position within the complete range of motion, whether its contraction would safely pull the femoral head into the cup or contribute to edge loading. The results show that all the muscles that insert into the distal femur, patella, or tibia could cause edge loading of a well-positioned cup when the hip is in deep flexion. Patients frequently use distally inserting muscles for movements requiring deep hip flexion, such as sit-to-stand. Importantly, the results, which are supported by in vivo data and clinical findings, also show that risk of edge loading is dramatically reduced by combining deep hip flexion with hip abduction. Patients, including those with sub-optimally positioned cups, may be able to reduce the prevalence of edge loading by rising from chairs or stooping with the hip abducted. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1172–1179, 2013. PMID:23575923

van Arkel, Richard J; Modenese, Luca; Phillips, Andrew TM; Jeffers, Jonathan RT

2013-01-01

418

High-flexion mobile-bearing knees: impact on patellofemoral outcomes in 159 patients.  

PubMed

Ethnic cultural demands of the patient have encouraged surgeons to use high-flexion designs. It has been speculated that these high-flexion designs may produce higher incidence of patellofemoral complications over conventional designs. We wish to report 5- to 7-year follow-up of this design with special emphasis on patellofemoral outcomes. We performed a prospective study involving 159 patients who underwent computer-assisted simultaneous bilateral total knee arthroplasty (TKA) with high-flexion design. Patients were evaluated clinically using Knee Society score (KSS), Western Ontario and McMaster University Osteoarthritis (WOMAC) score, and Hospital for Special Surgery patella score with a minimum follow-up period of 5 years. At last follow-up, mean scores were KSS (88.7), WOMAC (48.5), and HSS (86.7). All the scores improved postoperatively. Average preoperative range of motion was 108 degrees, which improved to 132 degrees postoperatively. There was no evidence of loosening or spin out in our study. Our study shows that TKA done using high-flexion rotating platform design results in near normal patellofemoral tracking patterns with improvement in function. The level of evidence of the study is IV. PMID:23955183

Jain, Sanjeev; Wasnik, Sandeep; Hegde, Chintan; Mittal, Amber

2014-04-01

419

Effects of Open and Closed Kinetic Chains of Sling Exercise Therapy on the Muscle Activity of the Vastus Medialis Oblique and Vastus Lateralis  

PubMed Central

[Purpose] The muscle strength of the quadriceps muscle is critical in patellofemoral pain syndrome. The quadriceps muscle supplies the power for dynamic patellar movement, and the vastus medialis oblique (VMO) and vastus lateralis (VL) enable the patella to stabilize during tracking. We followed the theories about open and closed kinetic chain exercises to design two exercises, sling open chain knee extension (SOCKE) exercise and sling closed chain knee extension (SCCKE) exercise. The purpose of our study was to research the changes in quadriceps muscle activity during both exercises. [Methods] Electromyographic analysis was used to explore the different effects of the two exercises. The MVC% was calculated for the VMO and VL during exercise for analysis. [Results] We found that the mean MVC% values of the VMO and VL during the SOCKE exercise were higher than those during the SCCKE exercise. The ratio of the VMO to VL was 1.0 ± 0.19 during the SOCKE exercise and 1.11 ± 0.15 during the SCCKE exercise. [Conclusions] The SOCKE exercise is targeted at quadriceps muscle training and has a recruitment effect on the VMO. The beneficial effect of the SOCKE exercise is better than that of the SCCKE exercise. PMID:25276016

Chang, Wen-Dien; Huang, Wei-Syuan; Lee, Chia-Lun; Lin, Hung-Yu; Lai, Ping-Tung

2014-01-01

420

Quadriceps tendon tear rupture in healthy patients treated with patellar drilling holes: clinical and ultrasonographic analysis after 36 months of follow-up  

PubMed Central

Summary Background: quadriceps tendon subcutaneous rupture is an uncommon injury affecting predominantly middle-aged men as a result of direct or indirect trauma; aim of this work is to evaluate clinical outcome and tendon morphology in patients treated surgically with transpatellar drilling suture. Methods: 20 patients (20 male) with an average age of 54 (42–59) were evaluated with a mean follow-up of 36 months. Measurements of range of motion (ROM) and of tight circumference were collected. Lysholm and Rougraff Score were also performed. All the patients underwent a US evaluation the morphologic changes of the repaired tendon. Results: mean active ROM was 1°–117°; average difference in the circumference of the quadriceps was 2.6% 10 C and 3.3% 15 C. The mean Lysholm Score calculated was 88/100; the mean Rougraff Score 17/25. At ultrasonographic evaluation all tendons were continuous; heterotopic ossification was present in 18 quadriceps tendons. Thickness was augmented in 18 quadriceps tendons and in 5 patellar tendons. Vascularization was always conserved. Lateral subluxation of patella was reported in 1 case. Conclusions: patellar drilling holes repair is a non-demanding procedure, inexpensive and technically uncomplicated. US evaluation confirms tendon healing; tendon remodeling does not affect patient’s clinical outcome and quality of life. Level of incidence: IV PMID:25332935

Verdano, Michele Arcangelo; Zanelli, Matteo; Aliani, Davide; Corsini, Tiziana; Pellegrini, Andrea; Ceccarelli, Francesco

2014-01-01

421

The genera Anafroptilum Kluge, 2011 and Neocloeon Traver, 1932, reinstated status, in North America, with remarks about the global composition of Centroptilum Eaton, 1869 (Ephemeroptera: Baetidae).  

PubMed

The mayfly genus Centroptilum Eaton, 1869, s.s., (Ephemeroptera: Baetidae), as presently understood, is not known to occur in North America. Nearctic species recently classified there belong either to Anafroptilum Kluge, 2011 or to Neocloeon Traver, 1932, reinstated genus. The North American endemic Neocloeon differs fundamentally from Anafroptilum in that it possesses a patella-tibial suture on the foreleg of larvae and female adults, a characteristic that is shared with certain other baetid genera. Neocloeon includes the obligate parthenogen N. triangulifer, new combination, and a sexual species, N. alamance, reinstated combination. Nearctic Anafroptilum include: A. album (McDunnough, 1926), new combination, A. asperatum (Traver, 1935), new combination, A. bifurcatum (McDunnough, 1924), A. conturbatum (McDunnough, 1929), new combination, A. minor (McDunnough, 1926), new combination, A. ozarkense (Wiersema & Burian, 2000), new combination, A. semirufum (McDunnough, 1926), new combination, and A. victoriae (McDunnough, 1938), new combination. Further study will be required to determine the species composition of Anafroptilum and Centroptilum, s.s., in the Palearctic and Oriental realms. Anafroptilum and Neocloeon are part of the Cloeon complex of genera, but Centroptilum, s.s., is not. PMID:24943435

Jacobus, Luke M; Wiersema, N A

2014-01-01

422

Manual Khalifa Therapy in Patients with Completely Ruptured Anterior Cruciate Ligament in the Knee: First Results from Near-Infrared Spectroscopy  

PubMed Central

Background: Manual Khalifa therapy has been practiced in Hallein, Austria, for more than 30 years; however, there are no scientific results available on the topic. Aims: The goal of the present study was to investigate possible acute effects of Khalifa therapy on regional oxygen saturation of knee tissues in patients with completely ruptured anterior cruciate ligament. Materials and Methods: We investigated 10 male patients (mean age ± standard deviation (SD) 35.9 ± 6.1 year) using a four-channel oximeter. The sensors were applied anterolaterally and anteromedially, beside the patella, on both the injured and the healthy (control) knee. Results: The results of the controlled study showed that values of oxygen saturation on the knee with the ruptured ligament were significantly increased (P < 0.001) immediately after Khalifa therapy, whereas the values on the control knee showed insignificant increases. Baselines values of the anterolateral side of the injured knee were significantly (P < 0.001) different from those of the anterolateral side of the control knee. The same effect was present on the anteromedial side; however, with a lower degree of significance (P < 0.05). Conclusions: Khalifa therapy was clinically successful in all 10 patients. Further, investigations and analyzes are necessary to explain the underlying mechanism. PMID:23814763

Litscher, Gerhard; Ofner, Michael; Litscher, Daniela

2013-01-01

423

Effect of 4 weeks of Acu-TENS on functional capacity and beta-endorphin level in subjects with chronic obstructive pulmonary disease: a randomized controlled trial.  

PubMed

Our recent studies showed that one session of transcutaneous electrical nerve stimulation on acupoints (Acu-TENS) improved forced expiratory volume in 1s (FEV(1)) in patients with chronic obstructive pulmonary disease (COPD). This study investigated the effect of 4-week Acu-TENS on physical and psychosocial function in these patients. Twenty-eight patients were randomly allocated to receive 4-weeks of 45-min, 5-days/week, of either Acu-TENS (over Dingchuan), Placebo-TENS (same protocol without electrical output), or Sham-TENS (over the patellae). Variables measured before and after intervention included FEV(1), forced vital capacity (FVC), 6-min walk distance (6MWD), St. George's Respiratory Questionnaire score (SGRQ), beta-endorphin and blood inflammatory marker levels. Only the Acu-TENS group attained significant improvement in FEV(1) (p=0.046), physical activity (p=0.007) and total SGRQ score (p=0.028). The increase in beta-endorphin (p=0.012) correlated positively with the improvement in FEV(1) (r=0.526, p=0.008). To conclude, 4 weeks of Acu-TENS improved the functional capacity of patients with COPD, probably due to the bronchodilation induced by beta-endorphin elevation. PMID:20601209

Ngai, Shirley P C; Jones, Alice Y M; Hui-Chan, Christina W Y; Ko, Fanny W S; Hui, David S C

2010-08-31

424

Role of uppermost superficial surface layer of articular cartilage in the lubrication mechanism of joints  

PubMed Central

The uppermost superficial surface layer of articular cartilage, the ‘lamina splendens’ which provides a very low friction lubrication surface in articular joints, was investigated using atomic force microscopy (AFM). Complementary specimens were also observed under SEM at ?10 °C without dehydration or sputter ion coating. Fresh adult pig osteochondral specimens were prepared from the patellas of pig knee joints and digested with the enzymes, hyaluronidase, chondroitinase ABC and alkaline protease. Friction coefficients between a pyrex glass plate and the osteochondral specimens digested by enzymes as well as natural (undigested) specimens were measured, using a thrust collar apparatus. Normal saline, hyaluronic acid (HA) and a mixture of albumin, globulin, HA (AGH) were used as lubrication media. The surface irregularities usually observed in SEM studies were not apparent under AFM. The articular cartilage surface was resistant to hyaluronidase and also to chondroitinase ABC, but a fibrous structure was exhibited in alkaline protease enzymes-digested specimens. AFM analysis revealed that the thickness of the uppermost superficial surface layer of articular cartilage was between 800 nm and 2 ?m in adult pig articular cartilage. The coefficient of friction (c.f.) was significantly higher in chondroitinase ABC and alkaline protease enzymes digested specimens. Generally, in normal saline lubrication medium, c.f. was higher in comparison to HA and AGH lubrication media. The role of the uppermost, superficial surface layer of articular cartilage in the lubrication mechanism of joints is discussed. PMID:11554503

KUMAR, P.; OKA, M.; TOGUCHIDA, J.; KOBAYASHI, M.; UCHIDA, E.; NAKAMURA, T.; TANAKA, K.

2001-01-01

425

Micro-anatomical response of cartilage-on-bone to compression: mechanisms of deformation within and beyond the directly loaded matrix  

PubMed Central

The biomechanical function of articular cartilage relies crucially on its integration with both the subchondral bone and the wider continuum of cartilage beyond the directly loaded contact region. This study was aimed at visualizing, at the microanatomical level, the deformation response of cartilage including that of the non-directly loaded continuum. Cartilage-on-bone samples from bovine patellae were loaded in static compression until a near-equilibrium deformation was achieved, and then chemically fixed in this deformed state. Full-depth cartilage–bone sections, incorporating the indentation profile and beyond, were studied in their fully hydrated state using differential interference contrast microscopy. Morphometric measurements of the indented profile were used in combination with a force analysis of the tangential layer to investigate the extent to which the applied force is attenuated in moving away from the directly loaded region. This study provides microscopic evidence of a structure-related response in the transitional zone of the cartilage matrix. It is manifested as an intense chevron-type shear discontinuity arising from the constraints provided by both the strain-limiting articular surface and the osteochondral attachment. The discontinuity persists well into the non-directly loaded continuum of cartilage and is proposed as a force attenuation mechanism. The structural and biomechanical analyses presented in this study emphasize the important role of the complex microanatomy of cartilage, highlighting the interconnectivity and optimal recruitment of the load-bearing elements throughout the zonally differentiated cartilage depth. PMID:17062019

Thambyah, Ashvin; Broom, Neil

2006-01-01

426

Osteology of the pelvic limb of the African elephant (Loxodonta africana).  

PubMed

The pelvic girdle was characterized by large, transversely-placed ilial wings. The femur was the longest bone of the skeleton and its fovea capitis was situated caudomedially between the epiphyseal line and the articular surface of the femoral head. A wedge-shaped patella articulated with the femoral trochlea. The bones of the crus were approximately half as long as the femur and consisted of the sturdy tibia and slender fibula. The condyles of the tibia were concave and the femoro-tibial joint was congruent with rudimentary menisci. The tarsus consisted of seven bones which were arranged in three rows. There were five metatarsal bones. Only four digits were present, the third and fourth consisted of three phalanges each while the second and fourth digits were smaller and consisted of two phalanges each. The first digit was represented by one proximal sesamoid bone only. A large, cartilagenous rod or prehallux was attached to the first tarsal and metatarsal bones. Proximal sesamoid bones were present on the plantar aspect of the trochleae of metatarsal bones 1-V. The pes was found to be digitigrade and the digits rested on a thick pad of elastic connective tissue and fat. PMID:7898898

Smuts, M M; Bezuidenhout, A J

1994-03-01

427

Localized accumulation of lead within and among bones from lead-dosed goats  

SciTech Connect

The principal aim of this study was to gain a better understanding of where lead (Pb) accumulates and how it is distributed, within the bones of dosed goats. Adult goats were periodically dosed with Pb over a number of years for the primary purpose of producing blood pools containing endogenously bound Pb, for the New York State Blood Lead Proficiency Testing Program. Bone samples (e.g., primarily tibia, femur, humerus, and radius) were collected post-mortem from 11 animals and were analyzed for Pb content by acid digestion and electrothermal atomic absorption spectrometry (ETAAS or GFAAS). Average tibia Pb levels were found to correlate strongly with the cumulative Pb dose (r{sup 2}=0.81). However, the concentration of Pb in different bones and even within a small area of the same bone varied tremendously. Blood-rich trabecular (spongy) bone, such as the patella and calcaneus, were much more enriched in Pb than was cortical (compact) bone. In some dosed animals, the Pb concentration in the tibia was markedly higher at the proximal and distal ends of the bone compared to the mid-shaft. The implications of these findings with regard to the noninvasive measurement of lead in bone by XRF methods are discussed.

Cretacci, Yan [Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, New York State Department of Health, P.O. Box 509, Albany, NY 12201-0509 (United States) [Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, New York State Department of Health, P.O. Box 509, Albany, NY 12201-0509 (United States); Department of Environmental Health Sciences, School of Public Health, The University at Albany, P.O. Box 509, Albany, NY 12201-0509 (United States); Parsons, Patrick J., E-mail: pparsons@wadsworth.org [Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, New York State Department of Health, P.O. Box 509, Albany, NY 12201-0509 (United States); Department of Environmental Health Sciences, School of Public Health, The University at Albany, P.O. Box 509, Albany, NY 12201-0509 (United States)

2010-01-15

428

Limpets counteract ocean acidification induced shell corrosion by thickening of aragonitic shell layers  

NASA Astrophysics Data System (ADS)

Specimens of the patellogastropod limpet Patella caerulea were collected within (pHlow-shells) and outside (pHn-shells) a CO2 vent site at Ischia, Italy. Four pHlow-shells and four pHn-shells were sectioned transversally and scanned for polymorph distribution by means of confocal Raman microscopy. The pHlow-shells displayed a twofold increase in aragonite area fraction and size normalised aragonite area. Size normalised calcite area was halved in pHlow-shells. Taken together with the increased apical and the decreased flank size normalised thickness of the pHlow-shells, these data led us to conclude that low pH exposed P. caerulea specimens counteract shell dissolution by enhanced shell production. The latter is different from normal elongation growth and proceeds through addition of aragonitic layers only, while the production of calcitic layers is confined to elongation growth. Therefore aragonite cannot be regarded as a per se disadvantageous polymorph under ocean acidification conditions.

Langer, G.; Nehrke, G.; Baggini, C.; Rodolfo-Metalpa, R.; Hall-Spencer, J.; Bijma, J.

2014-08-01

429

T2 relaxation time measurements are limited in monitoring progression, once advanced cartilage defects at the knee occur  

PubMed Central

Purpose To study the natural evolution of cartilage T2 relaxation times in knees with various extents of morphological cartilage abnormalities, assessed with 3T MRI from the Osteoarthritis Initiative. Materials and Methods Right knee MRIs of 245, 45–60 year old individuals without radiographic OA were included. Cartilage was segmented and T2 maps were generated in five compartments (patella, medial and lateral femoral condyle, medial and lateral tibia) at baseline and two-year follow-up. We examined the association of T2 values and two-year change of T2 values with various Whole-Organ MR Imaging Scores (WORMS). Statistical analysis was performed with ANOVA and Students t-tests. Results Higher baseline T2 was associated with more severe cartilage defects at baseline and subsequent cartilage loss (P<0.001). However, longitudinal T2 change was inversely associated with both baseline (P=0.038) and follow-up (P=0.002) severity of cartilage defects. Knees that developed new cartilage defects had smaller increases in T2 than subjects without defects (P=0.045). Individuals with higher baseline T2 showed smaller T2 increases over time (P<0.001). Conclusion An inverse correlation of longitudinal T2 changes versus baseline T2 values and morphological cartilage abnormalities suggests that once morphological cartilage defects occur, T2 values may be limited for evaluating further cartilage degradation. PMID:24038491

Jungmann, P.M.; Kraus, M.S.; Nardo, L.; Liebl, H.; Alizai, H.; Joseph, G.B.; Liu, F.; Lynch, J.; McCulloch, C.E.; Nevitt, M.C.; Link, T.M.

2014-01-01

430

The effect of breed-type and castration on bone growth and distribution in cattle.  

PubMed

Data from carcasses of 210 cattle (119 bulls and 91 steers) from 4 breed types, serially slaughtered from approximately 200-800 kg kg liveweight were used to test the hypothesis of similar gender dimorphism among breeds in relation to carcass bone growth and distribution. Relative to total bone weight, breed types tended to have similar growth rates for all bones other than the cervical vertebrae, ribs, tibia and fibula, and tarsus. Adjusted to the same total bone weight there were significant differences among breed types in bone weight distribution, but the differences were very small and probably of little economic importance. Castration stimulated growth of the lumbar vertebrae, hindlimb bones, patella and hindquarter bones but inhibited growth of the ribs, scapula, carpus, forelimb bone, and forequarter bone. At the same total bone weight, steers as compared to bulls showed a shift in bone weight distribution towards the hindquarter, pistol and long bones. There were small but significant breed x gender interactions in the distribution of some bones. PMID:1292480

Shahin, K A; Berg, R T; Price, M A

1992-01-01

431

Automatic knee cartilage delineation using inheritable segmentation  

NASA Astrophysics Data System (ADS)

We present a fully automatic method for segmentation of knee joint cartilage from fat suppressed MRI. The method first applies 3-D model-based segmentation technology, which allows to reliably segment the femur, patella, and tibia by iterative adaptation of the model according to image gradients. Thin plate spline interpolation is used in the next step to position deformable cartilage models for each of the three bones with reference to the segmented bone models. After initialization, the cartilage models are fine adjusted by automatic iterative adaptation to image data based on gray value gradients. The method has been validated on a collection of 8 (3 left, 5 right) fat suppressed datasets and demonstrated the sensitivity of 83+/-6% compared to manual segmentation on a per voxel basis as primary endpoint. Gross cartilage volume measurement yielded an average error of 9+/-7% as secondary endpoint. For cartilage being a thin structure, already small deviations in distance result in large errors on a per voxel basis, rendering the primary endpoint a hard criterion.

Dries, Sebastian P. M.; Pekar, Vladimir; Bystrov, Daniel; Heese, Harald S.; Blaffert, Thomas; Bos, Clemens; van Muiswinkel, Arianne M. C.

2008-03-01

432

Automatic segmentation of the bone and extraction of the bone cartilage interface from magnetic resonance images of the knee  

NASA Astrophysics Data System (ADS)

The accurate segmentation of the articular cartilages from magnetic resonance (MR) images of the knee is important for clinical studies and drug trials into conditions like osteoarthritis. Currently, segmentations are obtained using time-consuming manual or semi-automatic algorithms which have high inter- and intra-observer variabilities. This paper presents an important step towards obtaining automatic and accurate segmentations of the cartilages, namely an approach to automatically segment the bones and extract the bone-cartilage interfaces (BCI) in the knee. The segmentation is performed using three-dimensional active shape models, which are initialized using an affine registration to an atlas. The BCI are then extracted using image information and prior knowledge about the likelihood of each point belonging to the interface. The accuracy and robustness of the approach was experimentally validated using an MR database of fat suppressed spoiled gradient recall images. The (femur, tibia, patella) bone segmentation had a median Dice similarity coefficient of (0.96, 0.96, 0.89) and an average point-to-surface error of 0.16 mm on the BCI. The extracted BCI had a median surface overlap of 0.94 with the real interface, demonstrating its usefulness for subsequent cartilage segmentation or quantitative analysis.

Fripp, Jurgen; Crozier, Stuart; Warfield, Simon K.; Ourselin, Sébastien

2007-03-01

433

Automated planning of MRI scans of knee joints  

NASA Astrophysics Data System (ADS)

A novel and robust method for automatic scan planning of MRI examinations of knee joints is presented. Clinical knee examinations require acquisition of a 'scout' image, in which the operator manually specifies the scan volume orientations (off-centres, angulations, field-of-view) for the subsequent diagnostic scans. This planning task is time-consuming and requires skilled operators. The proposed automated planning system determines orientations for the diagnostic scan by using a set of anatomical landmarks derived by adapting active shape models of the femur, patella and tibia to the acquired scout images. The expert knowledge required to position scan geometries is learned from previous manually planned scans, allowing individual preferences to be taken into account. The system is able to automatically discriminate between left and right knees. This allows to use and merge training data from both left and right knees, and to automatically transform all learned scan geometries to the side for which a plan is required, providing a convenient integration of the automated scan planning system in the clinical routine. Assessment of the method on the basis of 88 images from 31 different individuals, exhibiting strong anatomical and positional variability demonstrates success, robustness and efficiency of all parts of the proposed approach, which thus has the potential to significantly improve the clinical workflow.

Bystrov, Daniel; Pekar, Vladimir; Young, Stewart; Dries, Sebastian P. M.; Heese, Harald S.; van Muiswinkel, Arianne M.

2007-03-01

434

Osteology and radiographic anatomy of the pelvis and hind limb of healthy ring-tailed lemurs (Lemur catta).  

PubMed

In family Lemuridae, anatomical variations exist. Considering its conservation status (near threatened) and presence of similarities between strepsirrhines and primitive animals, it was thought to be beneficial to describe the gross osteology and radiographic anatomy of the pelvis and hind limb of ring-tailed lemurs (Lemur catta) as a reference for clinical use and species identification. Radiography was performed in 14 captive adult ring-tailed lemurs. The radiographic findings were correlated with bone specimens from two adult animals. Additionally, computed tomography of the hind limbs was performed in one animal. The pelvic bone has a well-developed caudal ventral iliac spine. The patella has a prominent tuberosity on the cranial surface. The first metatarsal bone and digit 1 are markedly stouter than the other metatarsal bones and digits with medial divergence from the rest of the metatarsal bones and digits. Ossicles were seen in the lateral meniscus, inter-phalangeal joint of digit 1 and in the infrapatellar fat pad. Areas of mineral opacity were seen within the external genitalia, which are believed to be the os penis and os clitoris. Variations exist in the normal osteology and radiographic appearance of the pelvis and hind limb of different animal species. The use of only atlases from domestic cats and dogs for interpretative purposes may be misleading. PMID:23651234

Makungu, M; Groenewald, H B; du Plessis, W M; Barrows, M; Koeppel, K N

2014-06-01

435

Changes in chondrocyte gene expression following in vitro impaction of porcine articular cartilage in an impact injury model  

PubMed Central

Our objective was to monitor chondrocyte gene expression at 0, 3, 7, and 14 days following in vitro impaction to the articular surface of porcine patellae. Patellar facets were either axially impacted with a cylindrical impactor (25 mm/sec loading rate) to a load level of 2000 N or not impacted to serve as controls. After being placed in organ culture for 0, 3, 7, or 14 days, total RNA was isolated from full thickness cartilage slices and gene expression measured for 17 genes by quantitative real-time RT-PCR. Targeted genes included those encoding proteins involved with biological stress, inflammation, or anabolism and catabolism of cartilage extracellular matrix. Some gene expression changes were detected on the day of impaction, but most significant changes occurred at 14 days in culture. At 14 days in culture, 10 of the 17 genes were differentially expressed with col1a1 most significantly up-regulated in the impacted samples, suggesting impacted chondrocytes may have reverted to a fibroblast-like phenotype. PMID:23027577

Ashwell, Melissa S.; Gonda, Michael G.; Gray, Kent; Maltecca, Christian; O'Nan, Audrey T.; Cassady, Joseph P.; Mente, Peter L.

2012-01-01

436

[Disease picture of dysplasia epiphysealis hemimelica].  

PubMed

Dysplasia epiphysealis hemimelica - an epiphyseal developmental disturbance of the skeleton - is combined with exostose-like, tumor-simulating cartilaginous hypertrophy of bone tissue, mainly located at the epiphyses of the lower extremities and at the tarsal bones. In the case of multiple involvement the unilateral type prevails (hemimele type); within the epiphyses it is mostly the medial part which is undergoing changes. Rare sites are patella, head of the hip bone, shoulder joint, carpalia, more commonly affected are talus as well as other tarsal bones, distal femoral epiphysis and proximal and distal tibial epiphysis. Histologically, dysplasia epiphysealis hemimelica is identical to cartilaginous exostosis. Bone formation is taking place by enchondral ossification (epiphyseal osteochondroma). The ratio between male and female is 3:1. As a rule, this disease becomes manifest in early childhood or adolescence by indolent swellings of the joint region, restricted movement, axis shift, sometimes by differences in the length of the legs. Therapeutic guidelines are not unanimous. On one hand, correction osteotomy is not recommended until the completion of growth, while on the other hand excision of the cartilaginous hypertrophy in early childhood (before the age of 4) is postulated. Since there are less than 100 cases described in literature, another 8 cases of this extremely rare disease are to be presented here. PMID:3087078

Timm, C; Immenkamp, M; Roessner, A

1986-01-01

437

Optimization of the geometry of total knee implant in the sagittal plane using FEA.  

PubMed

The aim of this research was to investigate the optimization of the geometry of an UHMWPE type of knee implant in the sagittal plane with minimum amount of wear. Finite element analysis has been used to analyze our proposed 780 models consisting of different design parameters. Maximum stress occurring in the whole tibial component, on the surface or subsurface of the plate, was considered as a design parameter to evaluate the wear condition. By avoiding the small contact area and high stresses in the tibial part, the maximum safe flexion angles have been determined. Other effective design factors such as implant stability, roll back distance, patella lever arm, and minimum bone resection have also been considered. Taking into account the variable parameters in the geometry of the implant parts, all possible models for the femoral component, which is made from metal, and the tibial component, which is made from UHMWPE, have been built in ANSYS and analyzed in the sagittal plane. By considering the effective mechanisms of wear in polyethylene, the results of the analyses were used to find the optimized geometry of a knee implant. This is the model, which is expected to experience the minimum wear, besides having some other properties of an ideal knee prosthesis. PMID:14646058

Dargahi, Javad; Najarian, Siamak; Amiri, Shahram

2003-01-01

438

Optimizing femoral component rotation in total knee arthroplasty.  

PubMed

Femoral component rotation is important in total knee arthroplasty to optimize patellofemoral and tibiofemoral kinematics. More recently, the epicondylar axis has been cited as the definitive landmark for femoral component rotation. However, there are few studies to support the validity of this rotational landmark and its effect on the patellofemoral and tibiofemoral articulations. In the current study, a total knee arthroplasty was done in 11 knees from cadavers. The knees were tested with various femoral component rotations from 5 degrees internal rotation to 5 degrees external rotation referenced to the epicondylar axis and to the posterior femoral condyles. Each knee acted as its own internal control. The knees were actively ranged from 0 degrees to 100 degrees by a force on the quadriceps tendon in an Oxford knee simulator. Three-dimensional kinematics of all three components were measured whereas a multiaxial transducer imbedded in the patella measured patellofemoral forces. Femoral component rotation parallel to the epicondylar axis resulted in the most normal patellar tracking and minimized patellofemoral shear forces early in flexion. This optimal rotation also minimized tibiofemoral wear motions. These beneficial effects of femoral rotation were less reproducibly related to the posterior condyles. Rotating the femoral component either internal or external to the epicondylar axis worsened knee function by increasing tibiofemoral wear motion and significantly worsening patellar tracking with increased shear forces early in flexion. Based on the current study, the femoral component should be rotationally aligned parallel to the epicondylar axis to avoid patellofemoral and tibiofemoral complications. PMID:11716411

Miller, M C; Berger, R A; Petrella, A J; Karmas, A; Rubash, H E

2001-11-01

439

International multi-centre survivorship analysis of mobile bearing total knee arthroplasty.  

PubMed

We retrospectively reviewed the experience of a large international multi-centre study of primary total knee arthroplasty with mobile bearing design and modifications of the tibial component to allow for bicruciate preservation, posterior cruciate retention, or sacrifice. Twenty-seven surgeons performed 4,743 total knee replacements between 1981 and 1997. Implants inserted were 324 that retained both cruciate ligaments, 2,165 that retained the posterior cruciate, and 2,254 that sacrificed both cruciates. The patella was resurfaced in 2,838 and unresurfaced in 1,905. With failure defined as revision or reoperation for any reason, the overall survivorship was 79% at 16 years' follow-up. Revision occurred in 259 (5.4%) knees out of the entire cohort. The risk adjusted rates of failure were higher in females, younger patients, osteoarthritis, post-traumatic arthritis, and in patients who had a meniscal bearing prosthesis or patellar resurfacing. The most common cause of revision was bearing-related issues including chronic instability, bearing subluxation, bearing dislocation, or bearing wear in 2.3%. PMID:16547718

Stiehl, James B; Hamelynck, Karel J; Voorhorst, Paul E

2006-06-01

440

Biological activity of polyethylene wear debris produced in the patellofemoral joint.  

PubMed

Polyethylene wear is considered a threat to the long-term survival of total knee replacements. The aim of this study was to investigate the contribution that resurfacing the patella makes to wear debris-induced osteolysis following total knee replacement. Ultra-high molecular-weight polyethylene wear particles were isolated from simulator lubricant. Particle shape, size, and volume distributions were recorded allowing the osteolytic potential of the wear debris produced in the patellofemoral joint to be estimated using the concept of specific biological activity and functional biological activity. Values were compared with those reported for the tibiofemoral joint. Specific biological activity for the patellofemoral joint was not significantly different from the values for the tibiofemoral joint of total knee replacement devices, and therefore, has a similar potential to stimulate osteolytic cytokine release from macrophages. Functional biological activity was significantly lower for the patellofemoral joint compared with the tibiofemoral joint. Functional biological activity was significantly lower for the patellofemoral joint compared with the fixed bearing and rotating platform total knee replacement devices. However, as patellar resurfacing is commonly fitted as part of a total knee replacement system, this results in a 20% increase in overall functional biological activity for the system. Therefore, implanting a patellar resurfacing will increase the potential for osteolysis in the knee. PMID:22720390

Ellison, Peter; Tipper, Joanne L; Jennings, Louise M; Fisher, John

2012-05-01