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At least 145 records · Page 8Linked to original sources
PubMedDate not supplied

A delayed transverse avulsion fracture of the superior pole of the patella after anterior cruciate ligament reconstruction.

Patella fractures following anterior cruciate ligament (ACL) reconstruction using central one third patella-tendon autograft is a recognized although rarely reported complication of this procedure. Twelve reports of patella fractures after ACL reconstruction exist in the literature, although only half of these fractures occurred postoperatively. Two of the nonacute fractures occurred approximately 6 months postoperatively, one of them being an avulsion of the inferior pole of the patella and the other being a displaced transverse avulsion fracture of the patella. We report on a nondisplaced transverse avulsion fracture of the superior pole of the patella that occurred 1 year after ACL reconstruction despite bone grafting the defect in the patella at the time of surgery. We are unaware of any report of this kind in the literature.

Adolescent↗
PubMedDate not supplied

[Influencing factors of the patella alignment in TKR and operative soft tissue management].

UNLABELLED: The patella has a crucial effect on the postoperative result after TKR, as complication statistics demonstrate. What factors influence the patella alignment and through which surgical steps can it be centred? METHOD: Reviewing the findings from publications ranging from 1983 to 2000 and our own operative experience, we tried to establish all factors that could influence patella alignment after TKR. RESULTS: A complex overview is given about the dependency of the patella alignment on the design of the prosthesis, the soft tissue and bone preparation and the implantation technique, together with suggestions for intraoperative management for patella centralisation. CONCLUSION: To avoid any patella pathologies, it is of crucial importance to have comprehensive knowledge and to follow the described surgical steps strictly for patella centralisation, including the extensor mechanism. This is essential to achieve a satisfying functional result after TKR.

Arthroplasty, Replacement, Knee↗
PubMedDate not supplied

[Patella resurfacing in patients without substantial retropatellar knee pain symptoms?].

OBJECTIVE: The aim is of this prospective randomised study was to investigate the necessity of resurfacing the patella in combination with total knee arthroplasty in patients without or mild anterior knee pain before undergoing total knee replacement. METHODS: Between May 1999 and May 2000 fifty patients were enrolled in a prospective, randomised study. All patients received the same posterior-cruciate-sparing total knee replacement and were randomised to treatment with and without resurfacing of the patella. Inclusion criteria were primary osteoarthritis of the knee, preoperatively no pain when the patella was shifted during clinical examination, a maximal grade III radiological degeneration of the patella according to Sperner et al. and at most a mild anterior knee pain in preoperative interview. Evaluations consisted of the determination of the Knee Society clinical score, the completion of a patient satisfaction questionnaire, and radiographic assessment basing on the Knee Society roentgenographic evaluation and scoring system. All patients were examined preoperatively and 3, 6, and 12 months postoperatively. RESULTS: In all postoperative examinations patients with patella resurfacing demonstrated a higher overall Knee Society score. At month 6 the difference was statistically significant. The patient satisfaction questionnaire demonstrated no significant difference between both groups. However, regarding to relief of anterior knee pain and improvement of pain in general patients with nonresurfacing were less satisfied at all follow-ups. Furthermore, after 12 months all answers to the patient satisfaction questionnaire of the resurfaced group were better. Patella-associated revisions were performed in two patients without resurfacing. Radiographic analysis demonstrated no loosening, fracture, subluxation or dislocation. CONCLUSION: The presented study demonstrated after one year follow-up a better functional result, a higher degree of contentment and fewer complications after total knee replacement with patella resurfacing in patients without or mild preoperative anterior knee pain.

Aged↗
PubMedDate not supplied

[Position of the patella after knee endoprosthesis. A by radiology and computerized tomography controlled study].

The position of the Patellaimplant of 35 total knee arthroplasties (PCA) in regard to the other components, to patellar ligament and to correction of axis was analysed. The position of the patella was investigated with an average follow up of 38 months both radiologically and by computed tomography. A lateralisation of 4 mm on average and a lateral tilting of 4 degrees on average were found. The lateralisation of the patella in 30 and 60 degrees defilee radiographs demonstrated a significant dependence on the correction angle into valgus position. In lateral view and computed tomography the tilting of the patella is also dependent on the length of the ligamentum patellae. To avoid lateralisation and tilting of the patella in case of caudal position of the patella and a high intraoperative degree of correction into valgus position, careful check of the patella position is recommended in order to lateral release or medial capsular shift.

Adult↗
PubMed1997

Joint hypermobility in patients with chondromalacia patellae.

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 hypermobile joints and the total mobility scores were significantly higher in patients with chondromalacia patellae when compared to the control group (P < 0.001). There were more hypermobile knees among knee joints with chondromalacia patellae when compared with the knees of the control group (P < 0.01). Chondromalacia patellae were bilateral in 57% of our patients. It occurred more frequently in the longer leg and was associated with quadriceps muscle wasting in 50% of patients. Flat feet and backache were reported significantly more often in patients compared with the control group (P < 0.05). It is concluded that hypermobility of the knee joint may be a contributing factor in the pathogenesis of chondromalacia patellae.

Adolescent↗
PubMed1999

Harvest of patellar tendon (bone-tendon-bone) autograft for ACL reconstruction significantly alters surface strain in the human patella.

The purpose of this study was to measure the effect of bone-patellar tendon-bone autograft harvest for anterior cruciate ligament (ACL) reconstruction on the surface strain of the human patella. Through progressive removal of bone from the patella, three different defect shapes as well as the intact patella were tested in each of seven knees. Maximum principal strain and corresponding principal direction were determined from each of three gages around the defect for the four conditions (intact plus three defect shapes). There were no statistically significant differences in overall average surface strain between any of the defect shapes. Following graft harvest, overall average strain (all three defects combined) increased in the patella both medial (15 percent increase) and lateral (34 percent increase) to the defect, while decreasing in the region directly proximal (22 percent decrease) to the harvest site compared to the intact patella. A statistically significant 7.5 deg shift of principal direction from longitudinal toward a more transverse (lateral-superior to medial-inferior) direction was observed in the medial region when a shallow-dome defect was made. We conclude that removal of a bone block from the anterior, inferior part of the patella induces a significant redistribution of the surface strain. This results in greater local strain adjacent to the upper border of the bone block increasing the risk for patella fracture. This effect may be of importance in various complications known to occur after ACL reconstruction.

Aged↗
PubMed1999

Identification of LMX1B gene point mutations in italian patients affected with Nail-Patella syndrome.

Nail-Patella syndrome, or osteo-onychodysplasia, is an autosomal dominant disorder characterized by nail dysplasia, absent or hypoplastic patellae, iliac horns and nephropathy. Previous studies have demonstrated linkage of the Nail-Patella locus with polymorphic markers on human chromosome 9q34. Recently, point mutations in the LMX1B gene have been identified in Nail-Patella patients and in families with recurrence of Nail-Patella syndrome and open-angle glaucoma. We describe here the identification of additional point mutations in the LMX1B gene in a set of Italian patients affected with Nail-Patella syndrome: two deletions of 1 and 2 bp causing a frameshift in two sporadic patients and nonsense mutations in two familial and one sporadic cases have been identified. All the mutations affect the homeodomain of the LMX1B protein and could cause the Nail-Patella syndrome through a loss of function as well as a dominant negative effect. Haplotype analysis in the two familial cases carrying the same stop codon mutation suggests the presence of a founder effect. Finally, analysis of cDNA clones obtained from human fetal kidney has revealed the existence of two different transcripts of LMX1B gene likely due to an alternative splicing.

Alternative Splicing↗
PubMedDate not supplied

Semitendinosus tenodesis for repair of recurrent dislocation of the patella in children.

Recurrent dislocation of the patella is more common in girls than in boys. Although several predisposing factors may exist, patellar dislocation is most commonly associated with familial ligamentous laxity. Many surgical repairs have been described to stabilize the patella. We have found the semitendinosus transfer to the patella to result in a predictable, stable patellofemoral joint without risk of injury to the proximal tibial physis. Between January 1990 and December 1997, 29 children have been treated at the Children's Hospital of Eastern Ontario with a semitendinosus transfer for recurrent dislocation of the patella. Seven children were excluded from the study because of insufficient follow-up; consequently this series consisted of 22 children. Four children underwent bilateral repairs, hence 26 knees that have been operated on with this procedure were included in this study. There were three boys and 19 girls, with an average age at surgery of 14 years and 4 months, ranging from 8 years and 11 months to 17 years and 10 months. The average length of follow-up was 3 years and 2 months, ranging between 2 years and 7 years and 4 months. All children had experienced greater than three episodes of recurrent dislocation of the patella. Pain consistent with patellofemoral syndrome or chondromalacia was present in 17 of 26 knees. On clinical examination, 10 knees exhibited marked ligamentous laxity. There were nine positive patellar apprehension tests, and eight patellae were hypermobile. All children were treated with a semitendinosus transfer to the patella with concomitant tightening of the medial retinaculum and a lateral retinacular release. On long-term follow-up, 23 of the 26 knees (88%) were asymptomatic, and the child had returned to regular activities. Each child completed the Lysholm and the subjective component of the Zarins-Rowe questionnaire to determine the subjective results of the repair procedure. Three children complained of patellofemoral symptoms. One child experienced recurrence of the patellar dislocation, and one child developed medical patellar subluxation.

Adolescent↗
PubMed2001

Patella fracture after anterior cruciate ligament reconstruction with the patellar tendon: a comparison between different shaped bone block excisions.

Tensile failure of a patella after anterior cruciate ligament (ACL) reconstruction with autogenous patellar tendon graft is an uncommon but serious complication. One factor that may affect post-harvest patella strength is the shape of the bony defect. The effect of patella defect shape on ultimate tensile strength and mode of failure of the extensor mechanism has not been studied using physiologic moments. Twelve matched pair knee specimens were randomly distributed within three groups comparing rectangular versus triangular, rectangular versus circular, and circular versus triangular shaped patella defects. Specimens were loaded in tension to failure using physiologic moments. Patella fracture occurred in 21 of 24 specimens. Mean ultimate strength for all patellae with a circular defect was 2540 N (+/-651), rectangular defect was 3267 N (+/-920), and triangular defect was 3009 N (+/-1057). There was no significant difference in mean ultimate tensile strength between defect shapes or between matched pairs within the groups. Mode of failure also was similar in all three groups. No defect shape was found to be superior in this investigation comparing ultimate tensile strength or mode of failure between different shaped patella defects.

Aged↗
PubMed2003

Prospective trial of resurfaced patellaversus non-resurfaced patella in simultaneous bilateral total knee replacement.

INTRODUCTION: A prospective trial was carried out in simultaneous bilateral total knee replacement to compare the outcome of resurfaced versus non-surfaced patella. METHODS: Thirty-five patients between 1997 and 2002 had simultaneous bilateral total knee replacement with resurfaced patella on the left and non-resurfaced patella on the right knee using the same implant in both. RESULTS: There were 29 females and six males with a mean age of 65.3 years. Mean follow-up was 3.18 years. There was no significant difference between the resurfaced and non-resurfaced knees with respect to the overall Knee Society clinical score (p = 0.093 preoperative, 0.310 postoperative) or the pain (p = 0.715 preoperative, 0.395 postoperative) or function subscores (p = 0.126 preoperative, 0.317 postoperative). The postoperative range of motion was 109 and 110 degrees for the resurfaced patella and non-resurfaced patella respectively (p = 0.894). The post-operative knee scores between patients with or without pre-operative anterior knee pain (p = 0.238) and between those who were obese and non-obese (p = 0.387) were not significantly different. 82.9% of patients felt that the resurfaced knee and 80% felt that the non-resurfaced knee were much better than before. There was no major preference for either knee for climbing stairs and getting out of chair. CONCLUSION: The functional and symptomatic outcome of total knee replacement with or without patella resurfacing is the same in the local population. Also, the present study demonstrated no evidence that the weight of the patient or the presence of preoperative anterior knee pain should be considered as factors in the decision to resurface the patella.

Aged↗
PubMed2004

Comparison of patella cartilage volume and radiography in the assessment of longitudinal joint change at the patellofemoral joint.

OBJECTIVE: To compare radiological assessment of the patellofemoral (PF) joint and cartilage volume as measured by magnetic resonance imaging (MRI) in a longitudinal study. METHODS: One hundred and two subjects with osteoarthritis (OA) had baseline and followup skyline and lateral radiographs and MRI of the same knee. Duration of followup was 1.94 +/- 0.23 years. Mid-patella joint space and narrowest joint space were measured on lateral PF radiographs. Minimum joint space in the lateral and medial facets was measured on skyline radiographs. Rate of progression of PF joint OA was measured quantitatively at each site. Patella cartilage volume was measured from the MRI. The rate of change in each radiographic measure was compared to the rate of change in patella cartilage volume. RESULTS: The average loss of patella cartilage was 133 +/- 143 microm(3)/yr (4.4%). The loss of joint space over the same period on lateral radiographs was 0.7 +/- 2.6 mm at the narrowest joint space and 0.2 +/- 3.8 mm at the mid-patella joint space. On the skyline radiographs, the loss of joint space at the medial facet was 0.4 +/- 3.9 mm and 0.2 +/- 3.4 mm at the lateral facet. Only change in narrowest joint space on the lateral PF radiographs correlated with change in patella cartilage volume (R = 0.22, p = 0.03). CONCLUSION: Our data suggest that narrowest joint space measured on lateral PF radiographs correlates best with loss of patella cartilage. Further work will be needed to determine how different radiological measures of the PF joint relate to the disease process in OA.

Aged↗
PubMedDate not supplied

Radiological assessment of the patella position in the normal knee joint of adult Nigerians.

A method of determining the patella position as described by Insall and Salvati (1971) was re-evaluated. Lateral radiographs of 300 normal knee joints were obtained. The length of the ligamentum patellae was compared with the patella length. Both measurements were found to be approximately equal and the normal variation did not exceed 20%. The ratio of the length of the ligamentum patellae to the diagonal length of the patella was found to be a useful index in determining Patella height (position). Clinical value of these measurements are also discussed. It is therefore believed that these ratios irrespective of racial differences, are relatively simple, practical and reproducible. The Insall and Salvati method should therefore be preferred to other previously described methods of determining patella position.

Adult↗
PubMed2006

Determinants of change in patella cartilage volume in healthy subjects.

OBJECTIVE: To examine whether the amount of patella cartilage in healthy, middle-aged subjects is stable or changes over time, and what factors may influence the changes. METHODS: Eighty-five subjects (28 men and 57 women, mean age 55.5 yrs) had magnetic resonance imaging of their dominant knee at baseline and 2 years later. Patella and tibial cartilage volume was measured at baseline and followup. Risk factors assessed at baseline were tested for their association with change in patella cartilage volume over time. RESULTS: Mean annual percentage loss of patella cartilage was 2.1 (95% confidence interval: 1.1-3.2; p < 0.001). Age, gender, body mass index, and initial cartilage volume did not affect rate of change of patellar cartilage volume. There was a weak association between change in patellar cartilage volume and change in lateral tibial cartilage volume (R = 0.23, p = 0.03) but not medial tibial cartilage volume (R = 0.09, p = 0.43). CONCLUSION: In healthy subjects, a significant amount of patella cartilage is lost annually. The poor correlation between patella and tibial cartilage loss suggests that pathogenetic mechanisms for osteoarthritis in the patellofemoral and tibiofemoral joint may differ. Further work will be required to determine whether the rate of patella cartilage loss in healthy subjects is steady or phasic, and to determine which factors can be modified to reduce cartilage loss.

Aging↗
PubMed1990

Radiological assessment of the patella position in the normal knee of adult Nigerians.

A method of determining the patella position as described by Insall and Salvati was re-evaluated. Lateral radiographs of 300 normal knee joints were obtained. The length of the ligamentum patella was compared with the longest diagonal length of the patella. Both measurements were found to be approximately equal and the normal variation did not exceed 20%. The ratio of the length of the ligamentum patellae to the diagonal length of the patella was found to be a useful index in determining patella height (position). The clinical value of these measurements is also discussed. It is therefore believed that these ratios irrespective of racial differences, are relatively simple, practical and reproducible. The Insall and Salvati method should therefore be preferred to other previously described methods of determining patella position.

Adult↗
PubMed1994

Painful bipartite patella in young athletes. The diagnostic value of skyline views taken in squatting position and the results of surgical excision.

Nine patients with painful bipartite patella associated with young athletes were evaluated clinically and radiologically at an average of 60 months (range, 21 to 145 months) after excision of accessory nucleus of the patella. All patients were male and between 14 and 21 years of age when they were operated on. The indications for excision of separated fragments of the patella included: failure of nonoperative treatment for more than 3 months; radiographic evidence of significant irregularities of the articular surface of the separated fragment of the patella; and symptoms severe and prolonged enough to warrant surgery. Skyline views taken with the patient in a squatting position with weight bearing showed a wider separation of the accessory fragment from the main patella than did the nonweight bearing skyline views. This appears to be an important and useful diagnostic feature in a painful bipartite patellae; the authors propose that this radiographic examination should be called a "squatting position test". Histologically, the interface between the accessory and main patella was fibrocartilaginous, and the adjacent bone tissue was clearly demarcated by a dense lamina, indicating that the initial lesion was probably a traction lesion. All patients returned to full sports activity at their previous highest level within 4 to 7 weeks. The excision of accessory bone appears to be a simple and reliable procedure for avoiding prolonged postoperative treatment, reducing the length of incapacitation, and minimizing the danger of permanent stiffness of the joint.

Adolescent↗
PubMed1981

Patella alta and chondromalacia.

The Insall-Salvati (5) method of assessing the position of the patella was applied to 247 male patients made up from five different groups. Three of the groups were Greeks with normal knees (45 patients), knees already operated on for chondromalacia patellae (36 patients) and knees with a clinical diagnosis of chondromalacia patellae (57 patients). The other two groups comprised 58 African negroes and 51 Arabs, in all of whom a clinical diagnosis of chondromalacia patellae had been made. The ratio of the length of the patella to the length of the patellar tendon in the Greeks was 0.982 in the normal knees, 0.96 in the knees after operation and 0.971 in the knees with clinical chondromalacia. The ratio in Africans was 0.904 and in Arabs 0.929. Patella alta was found in 50% of the Greeks who had had operation or clinical chondromalacia, but it was more frequent in the Africans (74.1%) and the Arabs (68.6%). This difference is statistically significant (p less than 0.01 and p less than 0.05 respectively).

Adolescent↗
PubMed1978

Osteotomy of the patella in chondromalacia. Preliminary report.

There are many factors involved in the aetiology of chondromalacia of the patella. If possible, the appropriate operative procedure should be chosen for each patient, hence attempting to eliminate the cause of softening of the cartilage. Increased pressure over the lateral facet, with or without reduced pressure over the medial facet of the patella, resulting from lateral positioning or tilting of the patella, the Wiberg/Baumgartl-types III and IV, and the "Hunter's Hat" form are important causes. With reduced pressure, the cartilage is inadequately stressed and consequently receives insufficient nourishment. As the medial facet is particularly thick and has little contact with the femoral condyle, nutritional disturbance is almost a normal occurrence. Longitudinal osteotomy of the patella has been found to improve the contact of the medial surface of the patella with the femoral condylar groove. The analgesic effect of this surgical procedure may derive from the resultant reduction in subchondral interstitial pressure, presuming that the pain in chondromalacia patellae, like that of osteoarthritis, is a manifestation of raised intramedullary pressure. To ensure an improvement in patellar tracking the osteotomy is combined with a lateral capsular release.

Adult↗
PubMed2004

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

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 217 patients who had sport injuries and received arthroscopic surgery. The study group included 115 patients who had an ACL tear and received arthroscopic-assistant ACL reconstruction with middle-third bone-patella tendon-bone graft. The control group included 102 patients with internal disorders of the knee joint, including meniscus tear, plicae, or other chondral lesion, but without an ACL tear. We measured the patellar Insall-Salvati ratio [12] on the pre-operative X-ray films for all patients. The Insall-Salvati ratio in the ACL-tear study group is significantly smaller than the control group of internal disorders of the knee (0.99+/-0.11 vs 1.05+/-0.12, p=0.001). There is no significant difference in age, gender, the side of the involved knee, duration of symptoms, patella length and patella tendon length between the two groups. In conclusion, our study shows that patella infra has an association with ACL tears, and patella infra may be a risk factor for ACL tears. In patients with an ACL tear who had patella baja, the middle-third patellar tendon may not be an ideal graft for reconstruction.

Adolescent↗