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PubMed1995

The double patella syndrome.

First described by A. Trillat, the double patella is an uncommon clinical feature following repetitive injuries of the extensor mechanism of the knee. The first injury is a tendo-periosteal avulsion of the suprapatellar or, less frequently, infrapatellar tendon from the corresponding patellar pole. Often these avulsions are misdiagnosed and therefore treated only with a cast or no immobilization at all. Subsequent giving-way episodes lead to extensive ossification which is adjacent to or separated from the patella. The peculiar shape of this ossification overriding or underlying the primary kneecap justifies the denomination of double patella. Surgical treatment consists of removal of the calcification and reattachment of the tendon to the patella by transosseous sutures.

Adolescent↗
PubMed1985

Recurrent dislocation of the patella treated by the modified Roux-Goldthwait procedure. A prospective study of forty-seven knees.

We studied the results in forty-seven knees in thirty-seven patients - ten male and twenty-seven female - who had recurrent dislocation of the patella and were treated by a modified Roux-Goldthwait procedure (lateral retinacular release, medial transfer of the lateral patellar tendon without advancement, plication of the medial retinaculum, and advancement of the vastus medialis). Ten of the female patients had bilateral dislocation. The results were analyzed after follow-ups ranging from 3.0 to 16.3 years (average, 5.8 years). The study confirmed that a tangential radiograph of the patellofemoral joint, made with the knee in 20 degrees of flexion, is reliable in determining patellar displacement. The results were excellent in twelve knees, good in thirty-one, fair in one, and poor in three. The fair and poor ratings were due to pain caused by severe chondromalacia patellae. The patient with a fair result had had recurrent dislocations after the Roux-Goldthwait procedure due to a very lax synovial and capsular sac. Reoperation with tightening of the sac medially and laterally eliminated hypermobility of the patella in this patient and established straight patellar tracking. There was one serious complication, a large subcutaneous hematoma with necrosis of a skin flap. The patients with mild chondromalacia improved and showed no progressive patellofemoral arthritis after simple realignment, while those with severe chondromalacia were not improved by shaving, drilling, and realignment. Preliminary results indicated that a modified Maquet procedure, in addition to realignment, may be indicated for patients with severe chondromalacia. This study demonstrated that the modified Roux-Goldthwait procedure, without advancement of the tibial attachment of the patellar ligament, can stabilize the patella without increasing patellofemoral compression. The procedure does not relieve the symptoms of severe chondromalacia of the patella but realignment is the first step in treatment of any form of patellofemoral arthrosis.

Adolescent↗
PubMedDate not supplied

Dynamic patellar brace: a new orthosis in the management of patellofemoral disorders. A preliminary report.

The diagnosis and treatment of patellofemoral dysfunction, especially subluxation of the patella, remains controversial. Many authors feel conservative treatment will give better long-term results than operative treatment. To aid in nonoperative treatment of patellofemoral conditions a dynamic patellar stabilizing brace has been developed. The brace applies an active, medially displacing force to the lateral border of the patella and maintains constant pressure during flexion, extension, and rotation of the knee. This brace consists of an elastic sleeve with a patellar cutout and two circumferentially wrapped "live" rubber arms which apply dynamic tension to a crescent-shaped lateral patellar pad. An elastic circumferential counterarm maintains proper positioning of the pad and prevents rotation of the brace. The brace, superior to other methods of patellar splinting, is felt to be useful in the diagnosis of suspected subluxation in patients without the classical stigmata of patellofemoral dysplasia. It has proven useful in the treatment of 39 cases of patellar subluxation and 4 of patellofemoral arthritis. In a number of cases symptoms were completely eliminated with prolonged use of the brace. The brace is felt to be beneficial in conjunction with vastus medialis rehabilitation in patellar subluxation in growing children; in patients with mild or occasional subluxation, especially during specific activities; in persons with dislocation or subluxation in which surgery is contraindicated or must be delayed; and in acute subluxation. The brace may also be helpful in the prevention and treatment of chondromalacia and patellar tendinitis.

Braces↗
PubMed1977

Coxofemoral luxation complicated by upward fixation of the patella in the pony.

Two cases of coxofemoral luxation complicated by upward fixation of the patella are described in the pony. Clinical signs included outward rotation of the stifle and foot and inward rotation of the hock with the stifle and hock joints fixed in extension. One case was treated by performing a medial patellar desmotomy with a resultant significant improvement in locomotion. Other cases of hip luxation reported in the literature, some complicated by upward patellar fixation, are reviewed. Hip luxation is principally seen in ponies and it is suggested that upward fixation of the patella occurring in some of these cases is a result of rotation of the limb produced by dislocation of the hip, which alters the normal anatomy and mechanics of the femoro-patellar joint and/or interferes with the normal leverage of the rectus femoris muscle.

Animals↗
PubMed1999

Etiological aspects in osteochondritis dissecans patellae.

In a retrospective study probable etiological factors of rare cases of osteochondritis dissecans of the patella were analyzed. Anamnestic data and data obtained from standardized roentgenography in the anterior-posterior, axial, and lateral views of the patella were evaluated. Anamnestic data provided no evidence of the etiology in addition to the fact that several patients mentioned a single or multiple trauma. In contrast to this, evaluation of the roentgenograms showed that most of the patients with osteochondritis patellae exhibited a flat articular surface of the patella (types I and V in Hertel's classification) and a distinct accumulation of the patellae with greater lateral than medial facet (types II and III in Wiberg's classification). Furthermore, the axial shape of the patellar groove exhibited a distinct accumulation of type III trochleae, representing a hypoplasia of the medial and hyperplasia of the lateral part of the trochlea. Evaluation of the lateromedial patellar alignment revealed in a distinct accumulation of grade II dislocation medially and laterally. Although the data were obtained from a rather small number of patients, in our opinion these results support the theory of biomechanical induction of osteochondritis dissecans patellae. Further dynamic analyses are needed to clarify biodynamic effects on the patella and the patellofemoral joint.

Adult↗
PubMed1995

MR imaging appearance of the extensor mechanism of the knee: functional anatomy and injury patterns.

Trauma to the extensor mechanism of the knee, a common clinical problem, can be accurately evaluated with magnetic resonance (MR) imaging. The extensor mechanism consists of the quadriceps muscle and tendon, patella, patellar tendon, and patellar retinacula. Injuries of these structures can be classified into partial and complete tears. Acute injuries are associated with edema, hemorrhage, and fluid collections; chronic injuries often demonstrate redundancy, atrophy, and retraction of the affected structures. MR imaging is useful in differentiating partial and complete tears and in evaluating tissue edema and hemorrhage. It also allows detection of unsuspected nondisplaced patellar fractures and chronic conditions due to repetitive trauma. Transient dislocation of the patella is an often clinically unsuspected entity for which MR imaging can serve an important diagnostic role. A detailed understanding of the functional and anatomic relationships of the extensor mechanism can greatly assist in interpretation of MR images of the traumatized knee.

Adult↗
PubMed2004

Anterior dislocation after total knee arthroplasty: a case report.

We report a case of anterior dislocation of an 11-year-old total knee arthroplasty in a 52-year-old woman with severe rheumatoid arthritis and osteoporosis. It was noteworthy that the mechanism of dislocation was unique in that massive wear of ultra-high-molecular-weight polyethylene, avulsion injuries of the medial collateral ligament and patellar tendon, and a stress fracture of the fibula secondary to the increased posterior tilt angle eventually caused anterior dislocation of the left knee without obvious trauma or infection.

Arthritis, Rheumatoid↗
PubMedDate not supplied

Recurrent dislocation of the patella in Turner's syndrome.

We report two patients with Turner's syndrome who presented with recurrent dislocation of the patella (RDP). Both had a positive family history of patellar instability. The association of RDP with Turner's syndrome has not been reported previously. A subsequent study in 14 patients with Turner's syndrome demonstrated radiographical patellofemoral incongruency in eight patients, but no clinical manifestation of patellar instability. Although the present study suggests a possible link between Turner's syndrome and patellofemoral incongruency, it could not ascertain whether or not Turner's syndrome predisposes a patient to RDP.

Adolescent↗
PubMed1980

Hip injuries in children and adolescents.

Hip injuries in children present a wide spectrum of problems. Frequently because of the severity of the trauma involved, other injuries may take precedence and may require modification of the usual approaches to treatment. However, certain precepts are essential to the successful treatment of these injuries and should be kept in mind regardless of the milieu in which they are found. In the child with a hip dislocation, the potential presence of an acetabular, femoral head, femoral shaft, patellar or tibial plateau fracture must always be considered. Specialized x-ray views are necessary for this evaluation. Laminography and arthrography may also be required. The essential feature of successful subsequent treatment is a gentle closed reduction performed within 24 hours of injury. Treatment of displaced fractures of the femoral neck remains an unresolved issue. Accurate reduction held with adequate internal fixation would appear to offer the best chance for a successful result. The possible complications of avascular necrosis, delayed union and non-union, coxa vara, premature closure of the epiphyseal plate, and shortening should be appreciated. Early institution of appropriate treatment may mitigate the ultimate effect of these potentially devastating problems.

Acetabulum↗
PubMed1980

Recurrent subluxation and dislocation of the patella in association with athletic injuries.

Seventy-one patients with 81 operations for correction of patellar instability are reviewed. Follow-up was for at least five years. The various preoperative symptoms, signs, and radiographic findings are presented. Two types of patellar instability become clear. One type is usually bilateral and secondary to general ligamentous laxity. A second type, usually unilateral with distinct physical findings, is secondary to trauma. The operative technique and results of surgery and physical therapy are discussed. A new rational approach to the operative treatment of recurrent subluxation and dislocation of the patella is proposed. The operative procedure would depend on the Q angle. For a Q angle of less than 14 degrees, a proximal realignment is sufficient. For a Q angle greater than 14 degrees, a distal realignment would be necessary in addition.

Athletic Injuries↗
PubMed1993

Dislocation following primary posterior-stabilized total knee arthroplasty.

From 1981 through 1991, 3,032 primary total knee arthroplasties were performed using the Insall-Burstein Posterior Stabilized Condylar Prosthesis (IB-I, IB-II, and IB-II modified) (Zimmer, Warsaw, IN). Fifteen posterior dislocations occurred: 4 with the IB-I system occurring 2 or more years after surgery, 10 with the IB-II system (8 occurring 6 months after surgery and 2 occurring 2-3 years after surgery), and 1 with the IB-II modified system occurring 9 months after surgery. Statistically significant differences for the rate of dislocation between both the IB-I and IB-II modified arthroplasties versus the IB-II arthroplasties were found (P < .001). In an attempt to identify a cause for these dislocations, the authors retrospectively assessed the 15 dislocated cases with respect to sex, age, weight, height, preoperative and postoperative Hospital for Special Surgery scores, preoperative and postoperative alignment, preoperative versus postoperative reconstruction dimensions, patellar thickness and height, and postoperative flexion and compared the results with those patients who did not experience dislocation. Possible etiologies and mechanisms of dislocation were sought. There were no significant differences between the control and study groups for any variable assessed, with the exception of postoperative flexion, which averaged 118 degrees for the study group and 105 degrees for the control group (P < .001). Conservative management was successful in 11 cases. In September 1988 the IB-II system was introduced; modification of the tibial insert was made in January 1990.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

Orthopedic pitfalls in emergency medicine.

Acute orthopedic problems make up a large part of everyday emergency department practice. Misdiagnosis of these injuries often results from failure to consider certain clinical entities as a cause of the patient's complaints, and may result in unnecessary complications for the patient. Indeed, missed orthopedic injuries are the leading cause of malpractice claims in emergency medicine. The orthopedic injuries that most notoriously escape detection by the primary care physician are closed tendon injuries of the hand, carpal bone injuries, occult fractures about the elbow, femoral neck fractures, posterior dislocation of the shoulder, epiphyseal plate injuries, fractures of the pubic ramus, patellar tendon rupture, Lisfranc injuries, compartment syndromes, and multiple injuries. If the physician is unaware of these entities when evaluating the patient, he will not make the diagnosis. This review is designed to heighten the primary care physician's awareness of these injuries, which are a common source of problems in the emergency department.

Aged↗
PubMed1997

Tensile stress of the lateral patellofemoral ligament during knee motion.

Abnormal patellar retinacular tension has been considered to result in patellar lateral subluxation/dislocation. In this study, an in vitro experimental model was developed to determine the tensile stress of the lateral patellofemoral ligament, the thickest portion of the retinaculum, under loading conditions simulating two knee motion patterns: passive knee motion and unweighted active knee extension. The results indicate that the tensile stress increased significantly before 30 degrees of knee flexion, which strongly supports the clinical findings that patellar subluxation/dislocation occurs at approximately 20 degrees to 30 degrees knee flexion angles.

Analysis of Variance↗
PubMed1991

Medial dislocation of the patella.

Medial dislocation of the patella is a previously unreported entity. This disorder can be disabling to the patient and may require a hospital visit for reduction. Three cases are presented in this article in which computed tomography demonstrated the dislocation. All three patients had undergone a lateral retinacular release to the involved knee for treatment of chronic knee pain or recurrent lateral patellar subluxation.

Adult↗
PubMed1992

Recurrent dislocation of patella: three kinds of surgical treatment.

The authors compare three surgical techniques for treatment of recurrent dislocation of patella. The best results, even in the correction of lateral patellar displacement, were achieved with proximal realignment, while the worst results occurred when lateral retinacular release was used alone. In distal realignment, the degree of correction necessary must be ascertained by thorough preoperative assessment of both patellar height and malalignment between femoral groove and tibial tubercle. If the medial retinacular structures are weakened, it may be necessary to perform proximal realignment. We believe that a single surgical option is insufficient, and that the best solution for each individual case should be chosen according to precise indications. The choices include proximal realignment, distal realignment, or a combination of both, while lateral release should always be used in combination with another technique.

Adolescent↗
PubMed1988

Arthroscopic lateral retinacular release using a modified superomedial portal, electrosurgery, and postoperative positioning in flexion.

A technique for utilizing a modified superomedial portal, 6 cm proximal to and in line with the medial edge of the patella, is described for observing patellar tracking and performing a lateral retinacular release. The lateral release is performed without tourniquet using electrosurgery, and the knee is positioned in 90 degree flexion for two days postoperatively. The technique was used in 53 patients with lateral patellar and soft tissue tenderness and pain, 31 of whom had lateral patellar subluxation documented on 45 degrees Merchant x-ray views. Patients with a history of dislocation or a Q angle of more than 18 degrees were excluded. Conservative treatment averaged seven months pre-operatively. Results in 75% of the patients (37 knees) were rated good or excellent at an average follow-up of 20 months. One postoperative hemarthrosis occurred. This technique facilitates patellar evaluation and lateral release under direct vision using the same portal, as well as permitting early range of motion postoperatively.

Adolescent↗