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PubMed1975

Dysplasia of the quadriceps mechanism: hypoplasia of the vastus medialis muscle as related to the hypermobile patella syndrome.

Disturbance of the patellofemoral mechanism is the most common cause of dysfunction in the knee, especially in athletes of all age groups. This is primarily a congenital familial abnormality due to poor development in the vastus medialis. The patella develops in the line of maximum pull of this muscle group; in this congenital condition it develops in line with the stronger antagonist to the vastus medialis, the vastus lateralis muscle. Therefore, the position in the extremity that the patella assumes is the result of abnormal muscle development. This brings about other changes in the lower extremity that increase the tendency of the patella to migrate laterally. This condition, hypoplasia of the vastus medialis muscle, exists in a large number of people (about 40% of my patient population) in an asymptomatic form that predisposes them to degenerative changes of the patellofemoral articulation later in life, even without symptoms related to dysfunction of the patellofemoral mechanism. These individuals are also predisposed to disturbances of the patellofemoral mechanism which may cause symptoms, that is, the painful knee for which they seek medical attention. The symptomatic types of dysplasia of the quadriceps mechanism are usually brought on by injury to the medical quadriceps retinaculum that stretches or tears it, allowing the lateral migration to increase and producing pain in the inner aspect of the knee. Disuse atrophy of the vastus medialis accentuates the clinical picture as the condition worsens. As the asymptomatic type may progress into the midly symptomatic variant and eacy may worsen into a more serious disabling variety as reinjury occurs, it is important to recognize each type and to treat them properly.

Humans↗
PubMed1999

In vivo determination of the patella tendon and hamstrings moment arms in adult males using videofluoroscopy during submaximal knee extension and flexion.

OBJECTIVE: The determination of patella tendon and hamstrings moment arms. DESIGN: The moment-arms were determined using a videofluoroscopy imaging method. BACKGROUND: The determination of hamstrings and quadriceps moment arms is important for the examination of muscle and joint forces in biomechanical applications. METHODS: Ten males performed one knee extension-flexion movement at a very slow (non-constant) angular velocity in front of the image intensifier screen of a videofluoroscopic system. The image of a calibration phantom with 2 cm squares was also recorded. Thirty five calibration points with known coordinates were digitized for the establishment of the polynomial equations that determined the coordinates of any point in the calibration phantom from its corresponding video coordinates. Fourteen control points were digitized and the difference between the actual and predicted coordinates was measured. The patella tendon and hamstrings (biceps femoris) moment arms to the tibiofemoral contract point were calculated. RESULTS: The mean error in the digitizing of the control points using the image deformation method ranged from 0.182 mm to 0.267 mm. The mean patella tendon moment arm ranged from 36.91 (SD 3.2) mm to 42.63 (SD 4.5) mm. The hamstrings moment arm ranged from 23.93 (SD 2.59) to 28.25 (SD 3.04) mm. CONCLUSION: The patellar tendon and hamstring moment-arms were determined using a videofluoroscopy method with acceptable accuracy. These parameters can be used for the biomechanical analysis of knee joint movements in two dimensional applications.

Adult↗
PubMed1999

Intercondylar dislocation of the patella with vertical axis rotation.

A rare case is presented of intercondylar dislocation of the patella with vertical axis rotation. The injury was the result of blunt trauma directed to the lateral border of the patella. The patient presented with the knee locked in full extension and with a vertical ridge-shaped deformity caused by the medial border of the patella facing anteriorly. Reduction was accomplished under intravenous conscious sedation by manipulation.

Adult↗
PubMed1985

Arthroscopic chondroplasty of the patella.

Following failure of conservative treatment, arthroscopic chondroplasty was performed on 41 knees in 40 patients with chondromalacia of the patella as the only lesion. Within a follow-up period averaging 40 months, results were excellent in 10%, good in 39%, fair in 44% and poor in 7%. Seventy-eight percent of patients were subjectively satisfied with their surgery. Age or sex of the patients, grade of the lesion, and duration of the symptoms prior to surgery did not correlate with the final result. The method is considered safe since the few complications recorded were minor and did not affect the end result. Arthroscopic chondroplasty of the patella for chondromalacia patella has proved to be as satisfactory as or superior to more radical surgical approaches; however, conservative care should be the initial and primary method of treatment for this disease.

Adult↗
PubMed2003

Resurfacing versus not resurfacing the patella in total knee arthroplasty: 8- to 10-year results.

Patellar resurfacing in total knee arthroplasty is a topic debated in the literature. Concerns include fracture, dislocation, loosening, and extensor mechanism injury. Residual anterior knee pain has been reported when the patella is not resurfaced. One hundred patients with osteoarthritic knees were prospectively randomized to either have their patella resurfaced or left not resurfaced. All patients were treated with a single prosthesis that featured an anatomically designed patellofemoral articulation (Anatomic Medullary Knee, DePuy, Warsaw, IN) Two patients in the unresurfaced group and one in the resurfaced group required repeat surgery for patellofemoral complications. At 8- to 10-year follow-up evaluations, Knee Society Clinical Ratings scores were not different between the 2 groups. Rates of anterior knee pain with walking and stair climbing were significantly less in the resurfaced group. Eighty percent of patients with a resurfaced patella were extremely satisfied with their total knee arthroplasty versus 48% without patellar resurfacing. When satisfied and extremely satisfied patients were grouped together, there was no difference between the 2 groups.

Aged↗
PubMed2003

Theoretical use of 3D CT to predict method of patella realignment.

Procedures for the treatment of patello-femoral malalignment are grouped into two categories, proximal realignment and distal realignment. However, no clear indications in respect of these realignments have been reported. We have tried to evaluate patello-femoral alignment three-dimensionally using CT. The results lead us to group patients with recurrent patella dislocation into three types. Type 1 comprises patients with normal patello-femoral alignment. Type 2 comprises patients whose patella only deviates laterally and who need proximal realignment. Type 3 comprises patients whose patella and tibial tuberosity both deviate laterally and who need both proximal and distal realignment.

Adolescent↗
PubMed2004

An unusual double patella: a case report.

Double patella following a 'sleeve fracture' in the lower pole of the patellar is rare and even more so after surgical treatment to the original injury. We report such a case in a boy injured at the age of 10, and presenting 3 years later with weakness and effusion. The management is described, including the technique of excision of the accessory patella and the lowering of the larger patella to a normal level. We believe that this is the first such case to be reported after surgical treatment of the primary fracture.

Child↗
PubMed1998

Nail patella syndrome in a cytogenetically balanced t(9;17)(q34.1;q25) carrier.

Nail patella syndrome (NPS) is an autosomal dominant disorder characterized by dysplasia of the nails and patella, decreased mobility of the elbow, iliac horns and in some cases nephropathy. Linkage studies have localized the NPS locus to chromosome 9q34 within a 1-2 cM interval between D9S60 and the adenylate kinase gene (AK1), but the gene has remained elusive. We have identified a balanced t(9;17)(q34.1;q25) associated with NPS. By using FISH with probes from 9q the breakpoint region was narrowed to a 17.0 cM interval between D9S262 and ABL, which includes the NPS critical region. The patient showed the typical clinical features of NPS such as hypoplastic, deep-set nails, a dislocated elbow, iliac horns, and a polygonal patella. This suggests that the translocation has resulted from a break within or near the NPS gene, causing defective expression. The translocation in our patient may aid in the identification of the NPS gene.

Chromosome Painting↗
PubMedDate not supplied

Linkage analysis in two large Italian pedigrees affected with nail patella syndrome.

Nail patella syndrome (NPS) or osteo-onychodysplasia, is an autosomal dominant disorder characterised by nail dysplasia, absent or hypoplastic patellae, iliac horns and nephropathy. Previous studies have demonstrated linkage of the nail patella locus to the ABO and adenylate kinase loci on human chromosome 9q34. Recently, informative recombination events placed the NPS locus within a 1-2 cM interval within D9S60 and the AK1 gene. We describe here linkage analysis performed in two large Italian pedigrees with 10 and 11 members affected, respectively. A set of highly informative markers have been analysed and the allele segregation in the two families confirmed the linkage to chromosome 9. The presence of three recombination events allows definition of the critical region with a centrometric boundary between markers D9S1881 and D9S1840 and a telomeric boundary between markers D9S315 and D9S290.

ABO Blood-Group System↗
PubMed1998

Thickness of the subchondral mineralised tissue zone (SMZ) in normal male and female and pathological human patellae.

The objective of this paper was to analyse sex differences of the thickness of the subchondral mineralised tissue zone (SMZ), and to find out whether systematic changes of SMZ thickness are associated with naturally occurring, non-full-thickness cartilage lesions of human patellae. In 32 methyl-methacrylate-embedded specimens (16 normal, 8 with focal medial, and 8 with lateral lesions) the SMZ thickness was determined, using a binocular macroscope and an image analysing system. In each case, the thickness distribution was reconstructed throughout the entire joint surface. The maximal and mean SMZ thicknesses were significantly higher in males than in females (P < 0.01). In normal patellae and those with lateral lesions, the thickness was significantly thicker laterally than medially (P < 0.05), but it was not in specimens with medial damage. Patellae with medial damage exhibited a significantly lower total mean and lateral mean (P < 0.05). A lower SMZ thickness was found directly beneath medial lesions than beneath lateral ones, but the local thickness was always in the range of that observed in normal specimens. We conclude that differences of patellar SMZ thickness exist between males and females. Naturally occurring cartilage lesions appear, however, not to be associated with local changes of SMZ thickness, but they may be associated with an altered regional distribution pattern within the joint surface.

Aged↗
PubMedDate not supplied

Arthroscopic patella realignment: An all-inside technique.

PURPOSE: Many methods of realigning the patella have been described. Most techniques for proximal realignment involve an open medial reefing or advancement of the vastus medialis obliquus. Arthroscopically assisted methods have been described, but these all involve the need for a medial incision to tie sutures. This article describes an entirely arthroscopic technique for proximal realignment that eliminates the need for an incision, and reports the 2-year follow-up results using this technique. TYPE OF STUDY: Retrospective review. METHODS: Over a 5-year period, 26 patients (29 knees) with patellar instability were treated with an outpatient arthroscopic all-inside medial reefing and lateral release. Arthroscopic reefing was performed by percutaneous passage of suture followed by arthroscopic retrieval and knot tying inside the joint. Before knot tying, a healing response was initiated along the medial retinaculum by either gentle shaving with a whisker blade or by radiofrequency thermal response. Rehabilitation consisted of 1 week of immobilization followed by an accelerated program of range of motion exercises and vastus medialis obliquus strengthening. RESULTS: At follow-up, 93% of patients reported significant subjective improvement. The average Lysholm score improved from 41.5 to 79.3 (P <.05). Preoperative and postoperative radiographs were measured for congruence angle, lateral patellofemoral angle, and lateral patella displacement, and all showed significant improvement postoperatively (P <.05). There were no complications and no redislocations. Patients reported a significant improvement in pain, swelling, stair climbing, crepitus, and ability to return to sports (P <.05). CONCLUSIONS: Arthroscopic patella realignment is a viable technique that offers results comparable or superior to published results for open or arthroscopically assisted realignment.

Adolescent↗
PubMed2002

Vastus lateralis release for painful bipartite patella.

PURPOSE: The purpose of this study was to evaluate the efficacy of vastus lateralis release for painful bipartite patella. We have also compared the results of open method versus arthroscopic method using a holmium:YAG laser system (OmniPulse Holmium Laser System; Trimedyne Inc, Irvine, CA). TYPE OF STUDY: This study was a nonrandomized control and cross-over trial. METHODS: Fifteen patients with 17 painful bipartite patella who underwent vastus lateralis release were included in this study. The average age of patients was 14.3 +/- 2.2 years. In 7 knees of 6 patients, vastus lateralis release was performed through a skin incision over the bipartite fragment, and in 10 knees of 9 patients, we performed the procedure arthroscopically with the holmium:YAG laser. We assessed clinical and radiographic data of the patients chronologically in both groups. RESULTS: In all patients, pain over the fragment disappeared within 4 weeks after the operation, and all returned to their previous sports activities at an average of 3.1 +/- 0.9 months postoperatively. Clinical assessment was classified as excellent in 13 knees and good in 4 knees. Bone union at 6 months after the operation was complete in 11 knees (64.7%) and incomplete in 6 knees (35.3%), and none of the knees was graded as not healed. Bone union in patients with an age of 15 or younger was significantly better than that in patients over 15 years of age (P <.05). Release under arthroscopy showed statistically better results in duration of knee effusion (P <.05), return of circumference of thigh (P <.05), and return of muscle strength (P <.05). CONCLUSIONS: Because vastus lateralis release is less invasive surgery with good results, we conclude that this procedure can be a first choice of operative treatment for painful bipartite patella.

Adolescent↗
PubMed1999

Histomorphometry of the aging human patella: histologic criteria and controls.

OBJECTIVE: A histomorphometric analysis of patellae from necropsies on persons between the third and tenth decades of life was carried out to trace the natural history of osteoarthritis. DESIGN: Minutiae of the histological changes in the surface and basilar portions of the articular cartilage were developed as criteria for the quantitation. A total of 99 patellas were harvested in the stated age range. The present study reports the results of ten grossly and radiologically normal specimens from subjects 23-32 years old served as controls. RESULTS: None of the control patellae were entirely histologically normal. Abnormality of the cartilage surface did not consistently proceed remodeling at the attachment to the subchondral plate. CONCLUSIONS: This observation throws into question the concept that osteoarthritis has a single histogenesis or always arises in articular cartilage.

Adult↗
PubMed2002

Osteonecrosis of the patella and prosthetic extrusion after total knee arthroplasty.

We report the occurrence of painless patella avascular necrosis and spontaneous prosthetic extrusion after total knee arthroplasty with lateral retinacular release, a previously unreported complication. The resultant wound was debrided and closed without complication or loss of knee function. We elected not to remove the fragments in this case because the patient remained asymptomatic, and the remaining patella almost certainly will reabsorb completely. We advise clinicians to pay careful attention to patella viability and prosthetic loosening when assessing postoperative radiographs of total knee arthroplasty, especially with lateral retinacular release.

Aged↗
PubMed1979

[Chondromalacia patellae--arthrographic observations on the genesis and diagnosis of cartilaginous damage (author's transl)].

Thanks to recent advances in arthrography, diagnosis of cartilaginous lesions has increasingly become a task of the radiologist. An accurate assessment of the cartilage of the femoropatellar joint can be established via double-contrast technique and so-called "défilé" projections, whereas the axial projection of the patella without contrast medium shows only secondary arthrotic changes of bone and is unsuitable for demonstrating early cartilaginous damage. The classification of dysplastic patellae into different types according to Wiberg and Baumgartl yields a statistical correlation with the frequency of chondromalacia, but does not give any conclusive evidence in individual cases. A special influence on joint mechanics and the development of chondromalacia patellae is exercised by a cartilaginous ridge of the medial patellar facette.

Adolescent↗
PubMed1979

[The appearances of chondropathia patellae on plain films (author's transl)].

The ability to diagnose chondropathia patellae on plain radiographs was studied in 64 patients in whom the disease had been confirmed either by operation or arthroscopy. All cases of stage III chondropathia were diagnosable by radiological examination; in stage I, 67%, and in stage II, 73% could be diagnosed. The diagnosis depends on the co-existence of marginal irregularities, irregularities of the subchondral bone lamellae, spotty diffuse demineralisation, marginal osteophytes, irregularities at the insertion of the quadriceps tendon and soft tissue changes such as joint effusions. These changes are best identified on the so-called "defilée" view. Disalignment of the axis of the patella and post-traumatic defects are of particular importance for the development of chondropathia, but in the present clinical material, the existence of dysplasia of the patella or of the femoral condyle was not associated with a demonstrable increase of chondromalacia.

Cartilage Diseases↗
PubMed1998

Collagen crosslinks in chondromalacia of the patella.

The aim of the study was to determine collagen concentration and collagen crosslinks in cartilage samples from chondromalacia of the patella. To study the extracellular matrix alterations associated to chondromalacia, we determined the concentration of collagen (hydroxyproline) and its hydroxylysylpyridinoline and lysylpyridinoline crosslinks from chondromalacia foci of the patellae in 12 patients and 7 controls from apparently normal cadavers. The structure of the collagen network in 8 samples of grades II-IV chondromalacia was examined under polarized light microscopy. The full-thickness cartilage samples taken with a surgical knife from chondromalacia lesions did not show changes in collagen, hydroxylysylpyridinoline and lysylpyridinoline concentration as compared with the controls. Polarized light microscopy showed decreased birefringence in the superficial cartilage of chondromalacia lesions, indicating disorganization or disappearance of collagen fibers in this zone. It is concluded that the collagen network shows gradual disorganization with the severity of chondromalacia lesion of the patella without changes in the concentration or crosslinks of collagen.

Adult↗
PubMed1996

[Differential indications for so-called "lateral release" in treatment of chondropathia patellae].

The success rate of the operation of lateral release for pain caused by the patella is reported as being between 14% and 99%. The choice between arthroscopic or open procedures does not seem to affect the results. The wide ranges of results probably reflects differences in patients selection or the method and investigations of follow up. The early term outcome usually show better results than long term follow up. This study evaluates the indications for the operation of lateral releases and discusses the result of 36 out of a total of 42 patients who were follow up for 3 years later surgery. We found that an insufficiency of dysplasia of the vastus medialis, the laxity of the capsule and soft ligaments, and a strong lateral retinaculum were important factors in the indication for this procedure. The quadriceps angle was also of prime importance, but the minor forms of patellar dysplasia played only a minor role. In the so-called hyperpression syndrome, where the patella has a strong tendency to move laterally, the simple lateral release is the single most successful operation. The indication for procedures additionally to the lateral release is examined. We found that in a case with an insufficiently guided patella, a weak capsule and ligaments, an additional capsule roughing should be performed. The presence of early degenerative changes in the joint predisposes to poor results in operations such as abrasion and pride drilling. The results in our study were assessed using the Lysholm score. Our results show that the most successful technique was the combination of an arthroscopy and an extraarticular open operation controlled by arthroscopic means. This technique was not associated with major complications such as haemarthrosis and consecutive prolonged postoperative rehabilitation. Overall we achieved a rate of 83% of good or satisfactory results at more than 3 years using the indications and techniques described above.

Adult↗