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Ligamentous laxity is common in Trisomy 21 (Down's syndrome). The literature has numerous reports of atlanto-axial instability, patellar instability, carpal instability and other manifestations of joint instability. To date, no report has been published in the English literature describing non-traumatic unilateral or bilateral wrist dislocation either in trisomy 21 or in any other condition.
Throughout the ages, physicians have listened to sounds and felt vibrations from human joints in their attempts to diagnose pathology. They have used a wide vocabulary to describe these phenomena, but technology has been slow to provide recording and analytic equipment. Lately, accelerometers have been used with considerable success in a new noninvasive method now known as vibration arthrometry (formerly "arthrography"). The technique has been used in early detection of congenital dislocation of the hip and also in diagnosis of meniscal pathology. More recently, patellar vibration has been used to assess the mechanical properties of articular cartilage. Vibration arthrometry has also yielded new information on a possible damage mechanism associated with shock vibration that arises during cavitation of synovial fluid. Joint vibrations are therefore useful aids to diagnosis and may even be etiologic in orthopedic disease.
A kinematic magnetic resonance (MR) imaging technique for assessment of malalignment of the patella, involving the acquisition of multiple sequential axial images of the patellofemoral joint during the early increments of passive knee flexion, was used to evaluate 130 patients (235 symptomatic patellofemoral joints) showing clinical evidence of having patellar tracking abnormalities. Twenty-three of the patellofemoral joints had undergone previous surgical procedures for patellar realignment. In addition, 14 (28 patellofemoral joints) asymptomatic control subjects were studied. Normal patellar tracking was observed in all of the asymptomatic subjects and in 43 (17%) of the 260 patellofemoral joints in the patient population, 18 (7%) of which were symptomatic. Sixty-nine (26%) of the patellofemoral joints had lateral subluxation of the patella, 106 (41%) had medial subluxation of the patella, 21 (8%) had excessive lateral pressure syndrome, 19 (7%) had lateral-to-medial subluxation of the patella, and two (1%) had dislocation of the patella. Of the 235 patellofemoral joints with suspected abnormalities, 217 (93%) had patellar malalignment. Of the 23 patellofemoral joints that had undergone prior surgery, 20 (87%) had abnormal patellar tracking. Thirteen of 14 (93%) patellofemoral joints that had undergone a prior arthroscopic lateral retinacular release had a medially displaced patella.
The influence of lateral release of retinaculum on patellofemoral kinematics and contact characteristics after total knee arthroplasty was investigated in vitro. Lateral release altered the patellar tracking in patellar flexion, rotation, tilting, and translation. The contact force was decreased at high flexion angles. The contact area was slightly decreased and the contact region shifted laterally on the patellar button and medially on the femoral component at most of the flexion angles. The results suggest that the lateral release in total knee arthroplasty can change some patellar tracking and patellofemoral joint contact characteristics.
Concerning the therapy of fractures of the patella one has to discern between non-dislocated fractures being treated conservatively and all other kinds needing an operation. Between 1984 and 1987 172 patients with fractures of the patella were treated at the University Clinic of Traumatologic Surgery in Innsbruck. Transverse and vertical fractures were the majority. 84 patients were operated and most of them by means of tension band wiring principle. After operation patients normally received a plaster for approximately five weeks. Accompanying injuries were observed in several times. In five cases we had to do a reosteosynthesis because of secondary diastasis. One patient with a refracture could finally by cured with conservative methods.
Dysfunction of the patellofemoral mechanism presents in many ways. Results from different realignment procedures show great variability in patient outcome. A surgical technique is presented that attempts to correct all the abnormalities of patellofemoral maltracking. The procedure consists of a lateral release, a vastus medialis (obliquus) tendon advancement, and a tibial tubercle transfer. Along with being moved medially, the tubercle also is moved distally to correct patella alta and elevated anteriorly to reduce patellofemoral joint reaction forces. One hundred seven knees in 84 patients were reviewed. Fifty-five percent of patients had frank dislocation. The remaining patients had anterior knee pain and had abnormal patella tracking on examination. The mean followup was 5.6 years. Seventy-nine percent of patients had a good to excellent functional outcome and 84% of patients stated they would have the operation again. Two patients with marked generalized ligamentous laxity had recurrent dislocation of the patella.
Patellar instability is often missed by conventional axial views because transient subluxation of the patella essentially occurs during the first degrees of knee flexion (0 to 30 degrees), a position in which bilateral routine axial views are impossible to obtain. However, simple radiographic methods enable detection of both patellar instability and the often associated trochlear depth insufficiency. Every lateral radiograph of the knee depicts the depth of the proximal trochlear groove which is superior to 5 mm in a normal population. Upper trochlear depth insufficiency is frequently observed in the case of major patellar instability. Lateral views of the knee recorded during the first degrees of flexion (0 degrees-15 degrees) enable detection of patellar maltracking through the patellar tilt always associated with significant subluxation of the patella. Patellar maltracking may be studied dynamically by lateral fluoroscopy during progressive flexion of the knee. Unilateral 30 degrees axial radiographs with forced lateral rotation of the leg are definitely superior to conventional axial views in detecting transient patellar subluxation. These simple radiographic modalities should replace computed tomography in the search for patellar instability.
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Fractures of the patella occurred following implantation of 36 condylar total knee arthroplasties in 35 patients. The end results were evaluated in relation to fracture type after an average 4.5-year follow-up period. The follow-up observations included a physical examination, quantitative knee score, and roentgenographic evaluations of extremity alignment and implant position. Twenty-two of the 36 knees had a good or excellent knee score and 14 had a fair or worse score at the time of the latest follow-up evaluation. The satisfactory knees had an average arc of motion of 100 degrees, while the unsatisfactory knees had an average arc of motion of 80 degrees. Fourteen fractures through the mid-body or superior pole of the patella not involving the implant, cement, or quadriceps mechanism (Type I) and two nondisplaced fractures through the inferior pole of the patella (Type IIIB) were managed nonoperatively, with all knees rating either a good or excellent score. Fractures of the patella disrupting the quadriceps mechanism or implant/bone/cement composite (Type II) were managed operatively in the six knees. Fractures of the inferior pole of the patella with disruption of the patellar ligament (Type IIIA) were managed operatively in seven of eight knees (one patient refused surgery). Lateral fracture-dislocations were managed operatively in all six knees. Six of the knees operated upon had a good or better score, and nine knees were rated as poor or failed. Those fractures alignment and implant position were seen had the more severe patellar fractures and poorest outcomes.(ABSTRACT TRUNCATED AT 250 WORDS)
In studying the long-term follow-up of 39 cases of patellofemoral instability operated in our department for recurrent dislocation, we also analyzed their morphological appearance on X-ray. We compared the data given by Maldague and Malghem, Dejour and Walch for the pathological conditions of our cases with the same number of normal knees. This comparative analysis showed that measuring the bulging of the upper part of the trochlea and the depth of its groove on a lateral view is a reliable method to evaluate patellar instability. The classical axial view gives less useful information to quantify the instability. However, this axial view shows a particular aspect in the cases of severe instability: the fulcrum of the trochlea is displaced inwards while the inner trochlear facet is smaller or even absent. This precise radiological examination and the complete clinical examination with an analysis of the "morphotype" (Lerat) are necessary in the screening, diagnosis and treatment of severe patellofemoral instability.
In revising knee replacements 3 wear patterns have been noted; severe single facet wear which only occurs when the patella is dislocated or severely tilted, mild single facet wear from contact with the trochlear groove, and double facet wear. Double facet wear can occur when the knee flexes to more than 105-110 degrees, the edges of the patellar component then making contact with the edges of the femoral condyles across the cruciate gap. This double facet wear is potentially serious and may result in the patellar component wearing through.
The role and significance of acute arthroscopy have been evaluated in the treatment of knee joint injuries on the basis of findings during 59 arthroscopic operations which were conducted within two weeks after the accident. The injuries developed isolated in more than half of the cases (65%) whereas they appeared in a combination of two or more in 26% and in 9%, respectively. Injuries requiring operation were found in 91.5%, most of which were ruptures of the ACL (33 cases) and menisci (23 cases). In the case of ACL rupture, in the acute phase on sportsmen and physical workers primary arthroscopically assisted transligamental replacement was performed with patellar graft while in the case of proximal rupture of the ACL reinsertion and augmentation were carried out with semitendinosus tendon. The ruptures of dislocated eminentia were refixed in each case. In the case of the rupture of meniscus the refixation of the meniscus of resection of the ruptured part was attempted. By means of acute arthroscopy the lesion of the intraarticular structures or that of their combinations can be exactly diagnosed. Depending on the findings of arthroscopy the injuries can be treated immediately or operated on at a later time, thus preventing the joint from further deterioration.