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Although the number of bone dysplasias and their variable forms of expression seem to be increasing almost daily, in almost all instances orthopedic disease is detected at rather specific locations--the cervical spine, the thoracic and lumbar spine, and the knee and hips--and the orthopedic deformity is surprisingly constant.
In the diagnostic work-up of acute and chronic injuries to the knee, the patient's history together with the clinical findings are of decisive importance. Injuries to the cruciate and lateral ligaments, or to the menisci, as well as osteochondritis dissecans or chronic recurrent dislocation of the patella can usually be reliably diagnosed on the basis of information provided by the patient, and diagnostic manipulations. In this connection, Lachman's test, various drawer phenomena, the pivot shift test, and tests of the internal menisci described by McMurray, Payr, Steinmann, and Cabot as well as Apley's grinding test have all been described. The Wilson test can indicate osteochondritis dissicans; in chronic recurrent dislocation of the patella, Fairbank's apprehension test is positive.
Dislocations of the patella are discussed in the light of their pathogenesis, their possible injury pattern and their consequences. An exemplary case is presented. Especially the injury to the retropatellar cartilage with following chondromalacia--sometimes initiating the development of patellofemoral osteoarthritis--renders the dislocation of the patella a severe injury of the knee region. In case of spontaneous reduction and uncertain history the diagnosis may be difficult. The dislocation of the patella can be suspected if a hemarthrosis is found without an instability of the knee ligaments. The possibilities of an operative repair are described with special regard to the cartilage injury. Importance was layed upon the shape variabilities of the patellofemoral joint predisposing to recurrent dislocation.
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.
This study compares the fixed-bearing PFC Sigma Total Knee Arthroplasty to the recently introduced rotating-platform version of the same design in 26 patients. At an average follow-up time of 46 months for the fixed-bearing side and 16 months for the rotating-platform side, no significant differences were found in terms of knee preference, knee pain, range of motion, overall satisfaction, or Knee Society scores (KSSs). No revisions, subluxations, dislocations, or infections were seen. Also no radiographic evidence of component loosening, osteolysis, or malalignment was found in any knee. The results of cementing the PFC Sigma rotating-platform, posterior-stabilized total knee show excellent patient satisfaction at 1 year and comparable clinical and radiographic results to the fixed-bearing version.
PURPOSE: To inform physicians treating sport injuries of a rare and unique form of patella dislocation, the horizontal intra-articular dislocation of the patella. CASE SUMMARY: A young male sustained a direct blow to the upper pole of the patella and came into the emergency room with a knee locked at 75 degrees of flexion. He had an irreducible dislocation of the patella in which the patella was displaced inferiorly, rotated 90 degrees, and locked into the intercondylar notch of the femur. DISCUSSION: This injury occurs most often in young men and usually requires open reduction. Literature review indicates patients presenting a knee near full extension have a better chance for successful closed reduction, possibly because of a lesser degree of patella entrapment in the intercondylar notch. RELEVANCE: Most physicians are unaware of this rare type of patella dislocation. It can, however, be recognized by its typical mechanism of injury and clinical features. Unlike the common lateral patella dislocation, on-site reduction is not possible. This injury requires closed and often open reduction under general anesthesia.
Bucket handle meniscus tears constitute about 10% of all meniscal tears. Bucket handle tears of medial meniscus is three times more than lateral meniscus. Most of these tears are associated with anterior cruciate ligament (ACL) deficiency. Lateral meniscus lesions are more common with acute ACL deficiency, where medial meniscus lesions are more associated with chronic ACL deficiency. We identified bucket handle tears of each meniscus of a 30-year-old male patient while performing diagnostic arthroscopy during ACL reconstruction procedure. We present an ACL deficient knee with bucket handle tears of medial and lateral meniscus of the same knee and discuss the treatment.
We present an interesting case of intra-articular, horizontal dislocation of an adult patella without rupture of the quadriceps muscle tendon or a patellar fracture.
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The intra-articular migration of a femoral interference screw is a rare complication after anterior cruciate ligament (ACL) reconstruction in the knee. Only a few reports of cases have been published within the last few years and different approaches toward this complication have been described. We report the case of a 23-year-old female patient who was admitted with knee pain after undergoing an ACL reconstruction 4 years previously. After the clinical examination, a knee radiograph in 2 planes revealed a dislocated femoral interference screw lying in the popliteal fossa. During arthroscopy, the interference screw was retrieved through an additional posteromedial portal to avoid an arthrotomy. The causes for intra-articular screw migration are multiple and most cases were reported in the early postoperative period. The arthroscopic removal of a screw is recommended because of the lower morbidity.
This paper describes a series of nine short clinically oriented dissection exercises as supplements for freshman gross anatomy courses. These procedures heighten and focus student interest, and they do not extensively lengthen the time required to accomplish the regular dissection assignments. The exercises are: lumbar puncture, anterior approach for shoulder arthroplasty, acromioclavicular dislocation, fenestration of the diaphragm, appendectomy, cholecystectomy, display of the facial nerve as in parotidectomy, posterior approach for hip arthroplasty, and injuries to the knee ligaments and meniscectomy.
In 16 patients with chronic, symptomatic anterior cruciate ligament-deficient knees, sagittal displacement was studied in the standing position using fluoroscopic control and a simple device to support the knee. In slight weight bearing all knees but one had normal femorotibial alignment in the lateral view. During full weight bearing sagittal displacements between 2 mm and 17 mm were recorded in 14 patients. The largest displacements were obtained at different angles of inclination of the leg and flexion of the knee joint and were independent of the point of support of the knee joint. The reproducibility of this new standing technique was within 2 mm. A high correlation with previous methods of radiographic measurements of sagittal laxity was found. By the use of the normal relationship between the tibial eminence and the femoral condyles it is possible to record and measure sagittal displacements on a single lateral radiograph of the standing knee joint.
We report three cases of recurrent posterior dislocation of primary posterior-stabilized total knee replacements. In all of the cases, reduction was not possible under sedation alone, and general anaesthesia was needed to allow disengagement of the components and reduction of the dislocation. In addition, it was noted in all cases that the ability of the patients to flex their knee replacement excessively contributed to the instability. The design of the prosthesis, and issues of operative technique are discussed with reference to this serious complication.
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Sixty-seven Insall-Burstein (Zimmer Inc, Warsaw, Indiana) posteriorly stabilized total knee replacements were implanted in knees with a preoperative alignment > 10 degrees of valgus (average: 19.5 degrees). An anteromedial approach with release of the lateral ligaments of the femur was used. A lateral patellar release was necessary in 49% of cases. Fifty-one knees (76%) were reviewed with an average follow-up of 6 years. Pain at follow-up was absent or mild in all of the knees except one with aseptic loosening of the tibial and patellar components. The average flexion was 105 degrees. The results according to the Knee Society Rating System were excellent in 53%, good in 39%, fair in 6%, and poor in 2%. A patellofemoral "clunk" was present in three knees (6%), and one knee required arthroscopic debridment. The mechanical axis was within 5 degrees of neutral in 88%. A survivorship analysis was performed using failure requiring reoperation as the end point. There were four failures due to aseptic loosening, symptomatic lateral ligamentous instability, deep infection, and recurrent patellar dislocation. The patellar component had not been implanted in the knee with recurrent patellar dislocation due to severe bony erosion. The cumulative success rate was 95% at 10 years. These results indicate that release of the contracted lateral structures and implantation of a posteriorly stabilized prosthesis achieve a stable and well-aligned knee in 66 out of 67 knees. Attention must be paid to patellar tracking and realignment of the extensor mechanism.
Three cases of isolated anterior dislocation in the proximal tibiofibular joint are presented. The common aetiological feature was that injury occurred with the knee in hyperflexion and the foot inverted and extended. The symptoms of locking, pain and giving way may lead to an erroneous diagnosis of meniscal injury. Early diagnosis in the acute case enabled easy reduction. In the inveterate cases, resection of the head of the fibula gave complete relief of symptoms.
In the international scientific literature, MRI is reported to identify anterior cruciate ligament tears with high diagnostic accuracy (80-95%). In this prospective analysis, 274 MR examinations of the knee were performed to develop a method to measure even slight sagittal dislocation of the tibia relative to the femur as a predictor of an anterior cruciate ligament tear. Ninety-eight patients presented a healthy anterior cruciate ligament and were therefore considered as a control group. In 92 cases, a complete tear of the anterior cruciate ligament was observed; in 78 cases the injury was partial and in 6 cases the posterior cruciate ligament was injured. Our results had arthroscopic, surgical or clinical confirmation in all cases. The measurements were carried out on an MR image of the sagittal midplane of the knee and served to calculate a ratio (Y/X) which quantifies the degree of possible tibial dislocation. The results served to establish a range for classifying the status of the anterior cruciate ligament in three categories: 1) undamaged ligaments (Y/X < 3), 2) interstitial injury (2.2 < Y/X < 3) and 3) complete tear (Y/X < 2.2). This simple and easy-to-apply method should be considered complementary to conventional MR examinations. The results are extremely useful in the analysis of acute injuries where other radiologic and symptomatologic techniques are not completely reliable.
As a matter of principle, all lesions of the knee associated with haemarthrosis must be examined for internal injuries. Ligament ruptures are rare; usually, there are bony ligament tears that show up on x-ray film. Examination of ligament stability in children is useful only if the x-ray is negative and after the knee joint has been punctured under anaesthesia, and can be justified only in that case. Diagnosis is possible only by means of x-ray films taken in forced extreme joint position in two planes, with lateral comparison. Treatment of all non-dislocated ligament tears is conservative; slight dislocations can be tolerated in cruciate and capsular ligaments, since the epiphyseal cartilage is not affected. Surgery should be performed only if tears are considerably dislocated. Proximal tears of collateral ligaments are epiphyseal fractures that can be treated conservatively only if there is no dislocation; if they are dislocated, surgery is absolutely mandatory.