Anatomic reconstruction of the MPFL that respects the distal femoral physis in skeletally immature patients is a safe and effective technique for the treatment of patellofemoral instability and allows patients to return to sports without redislocation of the patella.

Combined anatomical reconstruction of the MPFL and femoral derotation osteotomy resulted in significant improvement of knee function and good patient satisfaction in young patients with severely increased femoral anteversion. No re-dislocation of the patella occured.

D. Dejour's classification is valid for typing trochlear dysplasia and is particularly useful in separating low-grade from high-grade dysplasia.

Conventional treatment of mild slipped capital femoral epiphysis consists of fixation in situ with wires or screws. Recent contributions to the literature suggest that even a mild slip may lead to early damage of the acetabular labrum and adjacent cartilage by abutment of a prominent femoral metaphysis. It has been suggested that the appropriate treatment in mild slipped capital femoral epiphysis should not only prevent further slipping of the epiphysis, but also address potential femoroacetabular impingement by restoring the anatomy of the proximal femur. Between October 1984 and December 1995 we treated 16 patients for unilateral mild slipped capital femoral epiphysis by fixation in situ with Kirschner wires. In this study we have reviewed these patients for clinical and radiological evidence of femoroacetabular impingement. There was little clinical indication of impingement but radiological evaluation assessing the femoral head-neck ratio and measuring the Nötzli alpha angle on the anteroposterior and cross-table radiographs showed significant alterations in the proximal femur. None of the affected hips had a normal head-neck ratio and the mean alpha angle was 86 degrees (55 degrees to 99 degrees ) and 55 degrees (40 degrees to 94 degrees ) on the anteroposterior and lateral cross-table radiographs, respectively. While our clinical data favours conventional treatment, our radiological findings are in support of restoring the anatomy of the proximal femur to avoid or delay the development of femoroacetabular impingement following mild slipped capital femoral epiphysis.

Failure to consider additional risk factors, technical intra-operative errors and inappropriate patient selection were identified as reasons for revision surgery after MPFL reconstruction. Identifying the potential causes of failure can help to treat and possibly prevent future complications.

Combined anatomic reconstruction of the MPFL and trochleoplasty reliably improved the stability of the patellofemoral joint in patients with severe trochlear dysplasia and no or mild degenerative changes. In addition, the described procedure showed significant improvement of knee function and good patient satisfaction without any episode of redislocations of the patella.

Quantitative measurements of the femoral trochlea have shown to be of limited value for the assessment of trochlear dysplasia. None of the quantitative measurements of the trochlea on transverse images could be assigned to the four-grade descriptive classification of trochlear dysplasia of Dejour. Additionally, measurements could not be reliably performed in high-grade trochlear dysplasia. However, trochlear inclination, trochlear facet asymmetry and depth of trochlear groove may help to distinguish between low-grade and high-grade dysplasia.

Radiographic measurements are commonly used to quantify the treatment results of hip dysplasia and assess further need of operative treatment. We investigated the interobserver and intraobserver reliability of the commonest radiographic techniques in the assessment of hip dysplasia in skeletally mature adults. Three observers independently analysed 100 hip radiographs of patients with hip dysplasia aged between 16 and 32 years. We measured centre-edge angle of Wiberg, acetabular angle of Sharp, acetabular index of the weightbearing zone, acetabular index of depth to width, ACM-angle, MZ-distance, acetabular head index, lateral subluxation and neck-shaft angle. In addition, the radiographs were reviewed a second time 3 months apart by two of the observers to assess intraobserver reliability. We found a high correlation (intraclass correlation coefficient) for interobserver reliability (0.76-0.87) and intraobserver reliability (0.70-0.92) for all radiographic measurements except acetabular index of depth to width, ACM-angle and MZ-distance. Depending on the clinical question we therefore recommend the use of one of the reliable measurements to assess the radiograph of a dysplastic hip.