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PubMed2005

Effects of lateral retinacular release on the lateral stability of the patella.

The objective of this cadaveric study was to evaluate quantitatively the effects of lateral retinacular release on the lateral stability of the patella. A materials testing machine was used to displace the patella of seven cadaveric specimens 10 mm laterally while measuring the required force, with 175 N quadriceps tension. The patella was connected via a ball-bearing patellar mounting 10 mm deep to the anterior surface to allow rotations. Patellar force--displacement behaviour was tested from 0 degrees to 60 degrees knee flexion. At 0 degrees , 10 degrees and 20 degrees flexion the mean force required to displace the patella 10 mm laterally was reduced significantly due to lateral retinacular release, by 16-19%. The average force required to displace the patella was also reduced for larger flexion angles, although this was not statistically significant. These findings suggest that lateral retinacular release may not be appropriate in treatment of patellar lateral instability.

Aged↗
PubMed2004

Lateral retinacular release: a survey of the International Patellofemoral Study Group.

PURPOSE: The purpose of this investigation was to determine current views regarding lateral release among experienced knee surgeons with a specific interest in the patellofemoral joint. TYPE OF STUDY: Scientific survey. METHODS: A questionnaire was developed and mailed to all members of an international group with a specific interest in disorders of the patellofemoral joint. Frequencies and percentages of responses were calculated for each question to determine surgeon consensus. We measured agreement among responses using the kappa statistic. This provided an indication of consistency for each question as well as correlation among the responses to different questions. RESULTS: The survey response rate was 60%. Isolated lateral release was estimated to account for only 1 to 5 surgical cases per respondent per year, or 2% of cases performed annually. In the setting of arthroscopy or exploration, 74% of respondents believed that lateral release calls for specific informed consent. Strong consensus was found that objective evidence is needed to justify lateral release, but agreement was poor as to what clinical evidence provides the most appropriate indication for the procedure. CONCLUSIONS: Even among experienced knee surgeons with a special interest in diseases of the patellofemoral articulation, isolated lateral release is rarely performed. Strong consensus was found that isolated lateral release should not be undertaken without prior planning in the form of objective clinical indications and preoperative informed consent. LEVEL OF EVIDENCE: Level V.

Arthroscopy↗
PubMed2005

Minimally invasive "crescentic" imbrication of the medial patellofemoral ligament for chronic patellar subluxation.

Chronic patellar subluxation is one of the many causes of anterior knee pain. Nonoperative management of this disorder is successful in many patients, but surgical intervention may be necessary for refractory cases. We present a surgical technique for chronic patellar subluxation that is minimally invasive and is focused specifically on the medial patellofemoral ligament.

Arthroscopy↗
PubMed2005

Long-term results of lateral retinacular release.

PURPOSE: We evaluated the outcomes of lateral retinacular release (LRR) after a long-term follow-up period of 5 to 12 years. TYPE OF STUDY: Long-term retrospective clinical follow-up study. PATIENTS AND METHODS: Between 1986 and 1994, 120 LRRs were performed in the Orthopaedic Department of the Catholic University of Rome. A total of 100 patients were evaluated. We divided the patients into 2 groups: group I contained 50 patients with patellar pain and no signs of instability; the remaining 50 patients, with clear signs of patellar instability, made up group II. Standard weight-bearing radiographs, axial views of the knee at 45 degrees , and dynamic computed tomography scans were performed in all patients preoperatively and at follow-up evaluation. Chondral damage was classified at the time of lateral release according to the criteria of Outerbridge and Dunlop. We used the Lysholm II score, which was modified for patellofemoral pathology and a clinical grading system of Busch and de Haven, to evaluate clinical outcomes at follow-up evaluation. RESULTS: In group I (pain), 70% reported satisfactory outcomes at follow-up evaluation compared with 50% in group II (P < .05) (instability). Compared with a previously published analysis of 3-year outcomes in this same patient population, there was very little change in group I patients, whereas group II showed a significant decrease in good outcomes over time. The worst results were obtained in cases with serious cartilage damage and exposure of the subchondral bone at the time of lateral release. CONCLUSIONS: LRR is a procedure offering a good percentage of success in the management of a stable patella with excessive lateral pressure and elective location of pain on the lateral retinaculum. In patellar instability the results are less favorable in long-term follow-up evaluation. The presence of high-grade joint surface injury is a poor prognostic indicator for lateral release. LEVEL OF EVIDENCE: Level IV.

Adult↗
PubMed2004

The contribution of the medial retinaculum and quadriceps muscles to patellar lateral stability--an in-vitro study.

Patellofemoral joint stability is a result of the restraining effects of the quadriceps muscles, the retinacular structures, and engagement of the bones. The role and significance of these mechanisms in restraining patellar lateral displacement was investigated in this study by measuring the force needed to cause 5 mm lateral displacement (i.e. the mechanical stability, or 'stabilising force') of the patella. Six cadaver knees had 175 N quadriceps load distributed among three muscle groups. With a force ratio matching the muscles physiological cross sectional areas, no significant change occurred in the patellar stabilising force between 0 and 60 degrees knee flexion, but a significant increase occurred between 60 and 90 degrees, presumably reflecting the contribution of the femoral groove. Variation of the quadriceps force distribution changed the stability significantly. Relaxing the vastus lateralis increased the patellar lateral stabilising force 52+/-8%, while relaxing vastus medialis reduced the stabilising force 47+/-9%. The minimum stabilising force was at 30 degrees knee flexion. Transection of the medial retinaculum reduced the lateral stabilising force 34% in the extended knee. This effect disappeared by 45 degrees knee flexion. It was concluded that the quadriceps muscles had a significant and consistent effect across the whole range of knee flexion, but the contribution of the medial retinaculum was restricted to extended knee postures.

Aged↗
PubMed2006

Patients with Ehlers Danlos syndrome and CRPS: a possible association?

Rare patients are left with chronic pain, vasodysregulation, and other symptoms that define complex regional pain syndrome (CRPS), after limb traumas. The predisposing factors are unknown. Genetic factors undoubtedly contribute, but have not yet been identified. We report four CRPS patients also diagnosed with the classical or hypermobility forms of Ehlers Danlos syndrome (EDS), inherited disorders of connective tissue. These patients had been diagnosed using standard diagnostic criteria for CRPS and for EDS. All had sustained joint injury; in three this had been surgically treated. The association of these two diagnoses leads us to hypothesize that EDS might contribute to the development of CRPS in one or more of the following ways: via stretch injury to nerves traversing hypermobile joints, increased fragility of nerve connective tissue, or nerve trauma from more frequent surgery. We review the clinical presentation of the different Ehlers Danlos syndromes and provide clinical criteria that can be used to screen CRPS patients for EDS for clinical or research purposes.

Adult↗
PubMed2002

Knee fractures in the athlete.

Sports-related fractures of the knee, although uncommon, do occur during athletic participation. The assessment and management of each fracture type have been emphasized in this article to provide a guideline for treating these acute knee injuries to a successful return to sports-specific competition. Anatomic fracture reduction is necessary to have optimal joint function in the knee as well as stability of fracture for early joint motion, promote bone healing, and avoid traumatic arthritis. This is especially crucial to the injured athlete, as residual deficits of the knee can greatly affect performance. Selection of low-profile implants at the time of surgery to prevent soft tissue irritation and possible implant removal must also be considered with the return to athletic activity.

Adolescent↗
PubMed2003

Sports participation of children with Down syndrome.

Patients with Down syndrome, by virtue of ligamentous laxity, are prone to a number of orthopedic problems with potentially serious sequelae. These disorders need to be evaluated throughout childhood and, when detected, appropriately managed. Given such management, the child with Down syndrome should be able to participate actively in and derive benefits from sports activities.

Athletic Injuries↗
PubMed2006

[Factors affecting reliability of TT-TG measurements before and after medialization: A CT-scan study].

PURPOSE OF THE STUDY: The purpose of this study was to evaluate the practical application of computed tomography (CT) measurements of the TT-TG (tibial tuberosity--trochlear groove) distance in patients undergoing surgery for patellar instability. MATERIAL AND METHODS: We reviewed retrospectively 42 patients (30 women, 12 men) who underwent surgery for patellar instability between 1989 and 2002. Objective evidence of unilateral instability was present in 36 patients and of bilateral instability in 6. Pre- and postoperative CT-scans of both knees were examined for each patient to measure the TT-TG distance for both knees (n = 48 knees). We also studied the difference in two consecutive TT-TG measurements made on 36 non operated knees. For the 48 operated knees, we compared the CT measurement of medialization (difference between the pre- and postoperative TT-TG) and the measurement made intraoperatively. RESULTS: For the 36 non-operated knees, the mean difference between two consecutive TT-TG measurements was 3.2 mm (range 0-13 mm). This difference was significant. For the 48 operated knees, medialization measured on the CT-scan was 8.6 mm on average. Medialization effectively measured intraoperatively was 6.9 mm on average for the same series of knees. Comparing these two types of measurement, the difference expressed in absolute value was 4.6 mm (range 0-20 mm). This corresponded to a 67% difference (4.6/6.9) for the TT-TG measurement compared with surgically performed medialization. DISCUSSION: For some authors, preoperative measurement of the TT-TG distance remains a useful tool for establishing therapeutic choices for patellar instability. It must be recalled however that the measurement error is to the order of 3.25 mm. Use of the TT-TG for postoperative assessment is however a much more difficult technique since the anatomic landmarks have been modified by surgery. A rigorously applied standard radiographic protocol is required. The surgeon can then conduct a critical analysis of the landmarks retained, the slices used and the values obtained.

Adult↗
PubMed2002

Comparison of three standard radiologic techniques for screening of patellar subluxations.

The presence of many "abnormal" types of PF joints in asymptomatic cases and the frequent unilateral complaints in morphologically symmetric joints indicate that emphasis must be placed on factors that cause "abnormal" PF joints to decompensate, rendering them symptomatic. These factors include hyperlaxity, puberty, overuse, or athletic activities. It is our conviction that full understanding of PF problems needs dynamic, three-dimensional motion analysis of patellofemoral relationships. At the present time these imaging techniques do not exist, as they require more powerful computer capacities. The absence of strict and reliable relationships between radiographic anomalies and clinical symptoms brings two reflections about the treatments in symptomatic cases: It is common sense to treat PPS by conservative methods first. Our study indicates that the goal should be to turn the symptomatic patella into an asymptomatic one, rather than correcting maltracking by vastus medialis training. The high failure rates at long-term follow-up of patellar maltracking correction by surgical methods such as lateral release and tibial tubercle transfer show us that correction of part or all of the anomalies does not always make the symptoms disappear. A nice lesson in humility for the orthopedist.

Female↗
PubMed2002

The immature athlete.

The skeletally immature athlete poses unique problems in diagnosis and treatment of injuries to the extensor mechanism of the knee. An accurate and detailed history and physical examination of the knee are essential for making a specific diagnosis and formulating an appropriate treatment plan. This article presents an overview of acute and chronic injuries of the extensor mechanism of the knee that are unique to skeletally immature athletes. The subjects of femoral trochlear dysplasia and medial subluxation of the patella are briefly discussed. The etiopathology, clinical evaluation, and management (non-operative and operative) of sleeve fractures of the patella and avulsion fractures of the tibial tubercle in children and adolescents are discussed. The pathoanatomy, clinical features, and management of synovial plica syndrome, Hoffa's syndrome, Osgood-Schlatter disease, and Sinding-Larsen-Johansson disease are presented.

Adipose Tissue↗
PubMed2003

Quantitative measurement of patellofemoral joint stability: force-displacement behavior of the human patella in vitro.

Patellofemoral joint instability is a common clinical problem. However, little quantitative data are available describing the stability characteristics of this joint. We measured the stability of the patella against both lateral and medial displacements across a range of knee flexion angles while the quadriceps were loaded physiologically. For eight fresh-frozen knee specimens a materials testing machine was used to displace the patella 10 mm laterally and 10 mm medially while measuring the required force, with 175 N quadriceps tension. The patella was connected via a ball-bearing patellar mounting 10 mm deep to the anterior surface to allow natural tilt and other rotations. Patellar force-displacement behavior was tested at flexion angles of 0 degrees, 10 degrees, 20 degrees, 30 degrees, 45 degrees, 60 degrees, and 90 degrees. Significant differences were found between the lateral and medial restraining forces at 10 mm displacement. For lateral displacement, the restraining force was least at 20 degrees of knee flexion (74 N at 10 mm displacement), rising to 125 N at 0 degrees and 90 degrees of knee flexion. The restraining force increased progressively with knee flexion for medial patellar displacement, from 147 N at 0 degrees to 238 N at 90 degrees. With quadriceps tension, the patella was more resistant to medial than lateral displacement. Our finding that lateral patellar displacement occurred at the lowest restraining force when the knee was flexed 20 degrees agrees with clinical experience of patellar instability.

Aged↗
PubMed2003

Bilateral patellar component dissociation in a patient with total knee arthroplasties.

We present a case of bilateral patellar component dissociation 6 years after bilateral total knee arthroplasty. The patient had undergone arthroscopic lateral releases bilaterally for patellar maltracking. After repetitive trauma, the patient experienced patellar component dissociation, which was treated arthroscopically by removing the patellar components and leaving the patellae unresurfaced. The patient's symptoms improved substantially. Our case highlights certain features of the etiology as well as the management of patellar component dissociation in the total knee arthroplasty, showing the important role of arthroscopy.

Aged↗
PubMed2004

Patellar fracture following surgery for patellar instability.

We present a case of patellar fracture in a teenager that followed a soft tissue realignment surgery for patellar instability. We propose that this fracture was due to disruption of the blood supply to the patella as a result of the procedure. To our knowledge this complication, which has been documented following Total Knee Arthroplasty, has not been documented in the English literature before.

Adult↗
PubMed2003

Synovial chondromatosis in the quadriceps tendon.

We present a case of synovial chondromatosis originating from the quadriceps tendon sheath, which caused a complete quadriceps tendon rupture. The patient was treated using marginal excision. The ruptured quadriceps tendon was repaired. This is the first description of a quadriceps tendon rupture associated with synovial chondromatosis.

Adolescent↗