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PubMedDate not supplied

Lateral retinacular release in patellofemoral subluxation. Indications, results, and comparison to open patellofemoral reconstruction.

A consecutive series of patients who have undergone arthroscopy and lateral retinacular release for patellofemoral subluxation was evaluated so that the results could be compared to an earlier series of open patellofemoral reconstructions. Of 96 patients, 4 had bilateral releases; therefore, 100 knees were evaluated. The average age was 28 years. Specific symptoms and signs were reviewed. All patients were initially treated conservatively with specific exercises. Failure of the exercise program to improve symptoms significantly, the patient's inability to perform normal daily activities, or expected associated pathology were indications for surgery. The surgical technique consisted of arthroscopy with treatment of associated pathology and lateral retinacular release using the Smillie meniscotome through the inferior lateral portal. The patella could be tilted approximately 90 degrees medially when the release was accomplished. Pain, function, and patellar instability were evaluated preoperatively and postoperatively by signs of tenderness on the retinaculum or bone, patellar mobility, effusion, muscle atrophy, and tone. Range of motion was also evaluated. Average followup was 36 months. When evaluated subjectively by the patients, pain improved from a mean preoperative grade of 3.4 to 1.7 postoperatively, function improved from 3.4 to 1.7, and instability from 3.4 to 1.6. Objective evaluation found that tenderness on the patella improved from a mean preoperative grade of 3.3 to 1.7 postoperatively. Tenderness on the retinaculum improved from 3.2 to 1.7. Patellar mobility improved from 3.3 to 1.7. Effusion dropped from 3.2 preoperatively to 1.5 postoperatively; quadriceps atrophy from a mean preoperative grade of 3.2 to 1.5, and quadriceps tone from 3.2 to 1.6.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1999

Evaluation of the association between medial patellar luxation and hip dysplasia in cats.

OBJECTIVE: To investigate the association between hip dysplasia (HD) and medial patellar luxation (MPL) in cats. DESIGN: Cross-sectional prevalence study. ANIMALS: 78 cats. PROCEDURE: A complete history was obtained. Cats were examined to detect MPL and HD. Radiographs of the stifle and hip joints were obtained. Hip joints were evaluated by use of Norberg angle, distraction index, and scoring consistent with that established by the Orthopedic Foundation for Animals. RESULTS: There were 43 male and 35 female cats mean age, 2.5 years). Eleven cats had clinical signs of disease in the pelvic limbs. Medial subluxation of the patella (subgrade 1) was seen in 31 of 33 cats with otherwise normal stifle joints. Medial patellar luxation was found in 45 of 78 (58%) cats, and 35 of 45 (78%) had grade-1 MPL. Bilateral MPL was seen in 32 of 45 (71%) cats. A weak association existed between MPL and HD, because cats were 3 times more likely to have HD and patellar luxation than to have either condition alone. Concurrent MPL and HD were detected in 19 of 78 (24%) cats, and HD was diagnosed radiographically in 25 of 78 (32%) cats (19 mild, 4 moderate, 2 severe). Eighteen of the 25 cats with HD had bilateral HD. CONCLUSIONS AND CLINICAL RELEVANCE: Clinically normal cats may have a certain degree of laxity in the stifle joint, evident as medial patellar subluxation (< grade 1). There is a weak association between MPL and HD, and both conditions may develop, alone or in combination, more frequently than has been reported.

Animals↗
PubMed1989

Lateral facet syndrome of the patella. Lateral restraint analysis and use of lateral resection.

Thirty-eight knees in 34 patients with an average age of 22 years were diagnosed as having lateral facet syndrome (LFS), a painful compressive arthropathy of the lateral facet of the patella. This diagnosis was based on the physical findings of tenderness at the lateral patellofemoral joint line, tenderness over the vastus lateralis obliquus (VLO) tendon just above the patella, a positive medial apprehension test, and marked resistance to medial patellar displacement with the knee flexed 30 degrees. The most common complaints were patellar pain with activity, pain with prolonged knee flexion, intermittent knee swelling, and giving way. At surgery, the VLO, the lateral retinaculum (LR), and the anterior fibers of the iliotibial tract (ITT) were sequentially divided from the lateral border of the patella. Each was temporarily reattached to a cuff of soft tissue left on the patella using surgical clamps to determine its contribution to lateral restraint. The VLO was found to be the primary restraint in one-half of the knees. In one-third of the knees, all three of the structures contributed equally. In six knees, the primary restraint was the anterior fibers of the ITT, whereas the LR was the primary restraint in only two. The distal ends of these three structures were then resected to prevent rescarring and retethering. At a minimum follow-up period of two years, 87% had satisfactory relief of their patellar pain, had returned to normal activities, and had no or minimal physical findings of LFS. The procedure is recommended for patients who have failed other procedures and in those whose symptoms cannot be controlled by activity modification, exercises, bracing, or medication.

Adolescent↗
PubMed1978

[Modified bridle-plasty in recurrent luxation of the patella].

For local operative correction of slipping patella, we recommend a modified plasty of the patellar retinaculum apparatus. This simple operation can even be performed on adolescents with still open epiphyseal cartilages. The technique of our operation is described. The early results during the last 30 months are very good. None of our 20 patients noted a reluxation, and all have resumed their sports.

Adolescent↗
PubMed1998

Clinical classification of patellofemoral pain and dysfunction.

The patellofemoral joint is a complex articulation based on its dependence on both dynamic and static restraints for stability. Classification of patellofemoral disorders has been frought with confusion. However, progress has been made in the classification and understanding of these disorders by improved understanding of the biomechanics of the joint and by clarification of the terminology to describe patellofemoral pathology. The term chondromalacia patella, although once used as an all-inclusive term for anterior knee pain, is now widely accepted as a term used to describe pathologic lesions of the patellar articular cartilage found at arthroscopy or arthrotomy. An adequate classification system should aid in proper diagnosis and treatment of specific problems. If properly devised, it should also aid in the comparison of results between different treatment centers. In addition, it should be a system that is simple and useful in the clinical setting with minimal use of complicated imaging techniques. From a clinical perspective, patellofemoral problems in the skeletally mature patient fall into three broad categories: 1) patellofemoral instability, i.e., subluxation or dislocation; 2) patellofemoral pain with malalignment but no episodes of instability; and 3) patellofemoral pain without malalignment. The myriad of patellofemoral disorders then fall into subclassifications of these categories. Treatment algorithms can be broadly developed based on the general category, with specific treatments based on the subclassification. In this paper, the authors will present a review of the pertinent literature documenting patellofemoral classification systems and develop concepts of clinical classification of patellofemoral disorders based on the three categories described above.

Adolescent↗
PubMed1980

Patellar malalignment: a treatment rationale.

A general review of present-day treatment for patellofermoral malalignment is presented. These regimens are viewed in light of known anatomical, biomechanical, and pathophysiological principles. We stress the need for a sound knowledge of biomechanical and pathophysiological principles prior to the initiation of surgical or rehabilitative techniques. Three major categories of surgery are discussed: 1) simple lateral release, 2) proximal "dynamic" realignment, and 3) distal patellar tendon realignment. A comprehensive rehabilitation program is presented based on sound biomechanical principles and known surgical techniques. We wish to stress the "non-surgical," conservative approach to patellofemoral malalignment through the use of a well-orgainzed and structured rehabilitation program.

Biomechanical Phenomena↗
PubMed1998

Surgical repair of patellar luxation in llamas: 7 cases (1980-1996).

OBJECTIVE: To evaluate anatomy of the stifle in llamas and determine outcome of llamas that underwent surgery for repair of patellar luxation. DESIGN: Anatomic and retrospective study. ANIMALS: 6 llamas with unilateral patellar luxation and 1 llama with bilateral luxations. PROCEDURE: 6 stifles from llama cadavers were dissected to determine anatomy. Medical records were reviewed to identify history, procedure, outcome, and complications of llamas that underwent surgery. RESULTS: 6 llamas had lateral patellar luxation (including the llama with bilateral luxations), and 1 had medial patellar luxation. Six llamas had a history of trauma before onset of clinical signs. Two llamas underwent tibial tuberosity transposition, but luxation recurred in both and 1 had problems with breakage of implants. The other 5 llamas underwent imbrication and release procedures; however, luxation recurred in 4 of the 5. Surgery was repeated in 2 llamas, with successful outcomes. CLINICAL IMPLICATIONS: Results suggest that imbrication and release procedures may be useful for correction of patellar luxation in llamas without other bony abnormalities. However, long (20 cm) imbrication and release incisions are needed for a successful outcome. Use of a sling after surgery, to allow a gradual return to weight bearing and exercise, may also be important.

Animals↗
PubMed1996

Patellar tilt and subluxation following subvastus and parapatellar approach in total knee arthroplasty. Implication for surgical technique.

Eighty-nine posterior-stabilized total knee arthroplasties (TKAs) were studied using a Merchant view to assess patellar tilt or subluxation. Forty TKAs were performed via the subvastus approach (SVA) and 49 via the standard parapatellar approach (PPA). Intraoperative tracking was assessed using a "no thumbs" test, and a lateral release was performed if necessary. Following the SVA, 40.0% of patellas tracked centrally compared to 44.9% for the PPA. With the SVA, a lateral release was necessary in 27.5% of procedures compared to 51.0% for the PPA. The data suggest that the no thumbs test may overestimate the need for lateral release following the PPA. Since there are fewer lateral releases following the SVA, reapproximation of the medial retinaculum to assess intraoperative tracking may result in fewer lateral release being performed without adversely affecting patellar position. Medial tilting of the patella is also found to be common; 29.7% of the patellas tilted this way, including 40.0% of knees operated via the SVA. Why this occurs is unclear, but the incidence of medial tilting increased after posterior-stabilized TKA.

Biomechanical Phenomena↗
PubMed1994

Frequency and distribution of medial and lateral patellar luxation in dogs: 124 cases (1982-1992).

From the medical records of 124 dogs, patellar luxations were classified as congenital or acquired, medial or lateral, and unilateral or bilateral; were graded 1 to 4; and were subdivided according to size of dog. The 4 breed-size categories were based on guidelines from American Kennel Club standards for adult height and weight. Findings from these records were compared with the results from dogs with other orthopedic problems. A majority of dogs had congenital (91; 82%), as opposed to acquired (17; 15%) patellar luxations. Distribution of dogs with patellar luxations according to breed size included 54 (98%) with medial patellar luxations (MPL) and 1 (2%) with lateral patellar luxation (LPL) in small breeds, 17 (81%) with MPL and 4 (19%) with LPL in medium breeds, 35 (83%) with MPL and 7 (17%) with LPL in large breeds; and 4 (67%) with MPL and 2 (33%) with LPL in giant breeds. Medial patellar luxation was observed in 110 dogs and 14 dogs had LPL. Cases of MPL and LPL in the same stifle or of medial and lateral patellar luxation in contralateral stifles in the same dog were not observed. Surgical correction was performed primarily in dogs with grade-3 and grade-4 patellar luxations. Medial patellar luxations and LPL were detected in all breed categories. Small-breed dogs were admitted almost exclusively with MPL. Lateral patellar luxation was found uncommonly; however, it was observed more often in larger-breed dogs. Prevalence of MPL was greater, when compared with that for LPL, in every size/breed category.

Animals↗
PubMedDate not supplied

Computed tomography of the normal patellofemoral joint.

Radiographic assessment of the patellofemoral joint (PFJ) is problematic because conventional views are cumbersome, difficult to standardize, and not reliable for displaying this joint with flexion of the knee less than about 30 degrees. We used computed tomography (CT) to obtain conveniently a direct transaxial view of the PFJ in ten normal human volunteers at different 0 degree, 20 degrees, and 45 degrees of knee flexion and during both contraction and relaxation of the quadriceps muscle. From the CT images we measured femoral trochlear angle, patellar centralization, femoral trochlear depth, and patella tilt angle. In full extension, with the quadriceps muscle relaxed, 19 of 20 knees showed the patella well centered in the femoral trochlear groove. The tilt and centralization of the patella were largely unchanged at 20 and 45 degrees of knee flexion with quadriceps contraction. CT appears to be an optimal method of studying the PFJ. The normal relationships described in this report can be the basis for evaluating patients with known or suspicious history of recurrent subluxation or dislocation of the patella.

Adult↗
PubMedDate not supplied

The problem of chondromalacia patellae.

Daily activity subjects the human patella to forces often several times the individual's body weight. Healthy cartilage can adjust to these forces if they are not too excessive, concentrated, or repetitive. Such abnormal stresses most frequently occur with the disturbance of normal patellar mechanical function. Chondromalacia patellae is the result common to a wide variety of unusual traumata. Treatment must be directed primarily not toward the damaged patellar cartilage but toward a correction of the mechanical abnormality causing it. Until proven otherwise, a young female complaining of knee joint pain, particularly if bilateral, should be considered as suffering from a subluxating patella, with or without chondromalacia patellae.

Adolescent↗
PubMedDate not supplied

Use of allografts in Pemberton osteotomies.

SUMMARY: Twenty patients treated with 26 Pemberton osteotomies with allograft bone wedges were retrospectively evaluated radiographically. Two patients undergoing four osteotomies were excluded because of incomplete records or <1 year of follow-up. Eleven of the remaining 18 patients had other procedures performed. Osteotomies all united radiographically within 3 months. The acetabular index improved from 33 degrees before surgery to 18 degrees after surgery, and the lateral migration index improved from 60% to 26%. This new technique of Pemberton osteotomy with patellar allograft wedges allows good correction of acetabular dysplasia with immediate graft stability. This stability often obviates the need for postoperative spica casting, even for patients undergoing bilateral procedures, thereby allowing more rapid rehabilitation.

Acetabulum↗
PubMed1974

[Clinical data on the use of estriol-testosterone combinations in small animal practice].

A combination of oestriol and testosterone oenanthate was tried in 14 different indications on 110 dogs and 5 cats of both sexes. Two formulations were used, containing in 1 ml either 0.15 mg oestriol and 2.25 mg testosterone or 1.15 mg of the former and 2.25 mg of the latter. Dosage was 0.2 ml per kg body weight, by i/m injection. The criterion for success was the degree of functional restitution, without taking into account pathological changes, which were generally unaffected. Good or very good results were obtained in hip dysplasia, arthitis and patellar luxation. None of the 50 bitches treated showed signs of oestrus or irregularities in the cycle. The formulation containing the lower drug concentration seemed to give the best therapeutic results.

Age Factors↗
PubMed1986

Patellofemoral incongruence in chondromalacia and instability of the patella.

We measured the patellofemoral congruence in tangential radiographic projections according to Merchant in 64 patients with unilateral patellar pain. The congruence angle was usually within normal limits. However, compared with the asymptomatic side, the angle was increased in chondromalacia and instability of the patella. A comparison of congruence angles of the two knees seems more valuable than a comparison with normal values.

Adolescent↗
PubMed1992

Preoperative computed tomography scanning and arthroscopy in predicting outcome after lateral retinacular release.

We initiated a study to look at preoperative, flexed-knee, midpatellar computed tomography (CT) scans and intraoperative arthroscopic findings of lateral patellar articular degeneration in predicting the results after lateral retinacular release for failed nonoperative treatment of anterior knee pain. Twenty patients with 30 painful knees underwent preoperative flexed-knee, midpatellar CT scans that were retrospectively classified by the method of Fulkerson into normal alignment, lateral subluxation, lateral patellar tilt, and combined tilt and subluxation. Arthroscopy was performed before open lateral release. The lateral facet of the patella was graded as either minimal changes (Outerbridge I or II) or advanced (Outerbridge III or IV) changes. Patients were followed for a minimum of 2 years and graded on a standard patellofemoral rating scale. Only 22 of 30 knees that were thought to be clinically malaligned, actually were malaligned by CT scan; eight CT scans were interpreted as normal. The results were further stratified into group A (CT-documented tilt, minimal facet changes), group B (CT-documented tilt, advanced facet changes), and group C (normal CT). Ninety-two percent of group A were rated good or excellent. Twenty-two percent of Group B rated good/excellent, 33% fair, 44% poor. Only 13% of group C rated good (one patient). Based on the results of the study, we recommend lateral release for anterior knee patients with CT-proven patellar tilt who have not responded to conservative treatment and have minimal facet changes with minimal or no subluxation. Lateral retinacular release should not be offered as a treatment to the patient with a normally aligned patella because poor results will most likely result.

Adolescent↗
PubMedDate not supplied

Anteromedialization of the tibial tuberosity for patellofemoral malalignment.

Anteromedialization of the tibial tuberosity is a new and highly effective technique for transferring the tibial tuberosity when anteriorization is desired in addition to medial shift of the patellar tendon insertion. Prompt primary bone healing can be achieved, allowing rapid rehabilitation with substantially improved patellofemoral mechanics. No bone grafting is necessary to achieve anteriorization, although only slight to moderate anteriorization is possible in most cases. Realignment of the patellofemoral mechanism and relief of patellofemoral contact stress can be achieved in one procedure.

Adolescent↗
PubMed1981

Guepar total knee prosthesis. Experience at the Vancouver General Hospital.

Eighty-three Guepar valgus-hinge prostheses and 30 prostheses with collinear femoral and the tibial components were inserted in 97 patients at Vancouver General Hospital between March 1975 and May 1978. One hundred and nine arthroplasties were reviewed between January 1979 and April 1980, after an average follow-up of 19 months. It was found that the amount of bone resected made arthrodesis difficult, that there was a very high incidence of patellar instability and that the disintegration of the Silastic bumper created a severe chemical synovitis. The results were excellent in 32, good in 23, fair in 8, and poor in 30. Patellar subluxation occurred in 28 per cent of the valgus prostheses, and in 10 per cent with the straight prostheses; it did not occur with the straight prostheses in rheumatoid joints. The chemical synovitis led to failure with devastating complications necessitating further operations in some knees.

Adult↗
PubMed2005

Bone plug length and loading angle determine the primary stability of patellar tendon-bone grafts in press-fit ACL reconstruction.

The present study was conducted to evaluate the influence of bone-plug length on the primary stability of patellar tendon-bone grafts, using a femoral press-fit fixation technique. Forty-eight human PTB grafts with a patellar bone-plug length of 15 mm and 25 mm were obtained from 24 human cadavers (mean age 72 years) and implanted to porcine femora in a press-fit fixation technique. Tensile loading was performed at 10 mm/s until failure at varying loading angles of 0 degrees, 30 degrees and 60 degrees. Compared to 25 mm, a significant decrease of primary graft stability was recorded in the testing of 15-mm bone plugs. For both plug lengths, the ultimate load to failure increased with rising the loading angles. While axial graft loading exclusively caused plug dislocation, the predominant mode of failure was tendon rupture at 60 degrees loading angle. We conclude that 15-mm bone plugs do not result in a sufficient stability for early aggressive rehabilitation and therefore 25-mm bone plugs are recommended for the femoral press-fit technique.

Aged↗