Objectives. For a long time lateral release (LR) was performed as a standard procedure both, for patellofemoral pain syndrome (PFPS) and patellofemoral instability (PFI). However, recent biomechanical studies have shown that LR is not useful for decreasing the lateral force onto the patella, but is increasing not only medial but also lateral PFI. Furthermore, pain on palpation over the lateral patellofemoral joint space can result in patients treated with extensive LR. We postulate that in case of persistent PFI or PFPS after failed LR the reconstruction of the lateral retinaculum as an addition of the reconstruction of the medial patellofemoral ligament (MPFL) is necessary in terms of decreasing medial PFI as well as lateral pain. Materials and Methods. In between 03/07 and 04/09 we have seen a total of 25 patients (20 f, 5 m) with persistent PFI and palpatory pain over the lateral retinaculum due to unsuccessful treatment of PFI with a LR. These patients have undergone revision surgery with an anatomical reconstruction of the released lateral retinaculum in combination with a reconstruction of the medial patellofemoral ligament (MPFL) in an aperture-technique using the gracilis tendon. The average age at time of operation was 26.2 ± 9.8 years. Preoperatively, as well as 6 weeks, 3 months, 6 months, and 12 months postoperatively, clinical examinations were performed and subjective as well as objective scores (Kujala-, Tegner-, IKDC-score) were evaluated. Regarding radiological parameters measurement of patellar tilt and shift was carried out on axial radiographs before and after the operation. Results. During the first twelve months after the operation only one redislocation could be recorded. Pain on palpation over the reconstructed lateral retinaculum was remaining in four patients (16%). Although several patients complained about persistent patellofemoral pain on exertion or after enduring flexion of the knee, all of them reported about an improvement of their pain situation. This fact is reflected in a highly significant improved but still moderate IKDC- (from 46.5 ± 14.9 to 68.9 ± 22.7, p<0.001) and Kujala-score (from 47.7 ± 15.3 to 74.8 ± 24.8, p<0.001) at the one year follow up. As far as sports activity is concerned, a statistically significant improvement of the Tegner-score up to 4.7 ± 2.4 (preoperative 2.3 ± 1.5, p<0.001) could be achieved. The radiological analysis showed a highly significant decrease of both, patellar tilt (from 15.4 ± 6.5 to 10.3 ± 6.2, p<0.001) and patellar shift (from 4.3 ± 3.3 to 2.5 ± 1.3, p=0.002). Conclusions. After one or more unsuccessful previous efforts of stabilizing the patella by LR, the technique performed in this essay leads to a considerable improvement of subjective scores and objective clinical and radiological parameters as well as sports activity

Aims

The aim of this study was to investigate the rate of revision for distal femoral arthroplasty (DFA) performed as a primary procedure for native knee fractures using data from the Australian Orthopaedic Association National Joint Arthroplasty Registry (AOANJRR).

Background. A number of studies have reported on the early failure of the Oxford unicompartmental knee arthroplasty. However, less evidence is available regarding the outcome following revision of failed unicompartmental knee prostheses to total knee arthroplasty. The aims of this study were to determine the time to failure for the Oxford unicompartmental knee arthroplasty and to assess the short-term outcome following revision surgery. Methods. Details of consecutive patients undergoing revision of an Oxford unicompartmental knee arthroplasty to a total knee arthroplasty at our centre between January 2000 and December 2009 were collected prospectively. Data was collected on patient demographics, indication for revision surgery, and time to revision from the index procedure. Clinical and radiological outcome following revision arthroplasty was also assessed. Results. During the study period 22 (4.5%) of 494 Oxford unicompartmental knee arthroplasties were revised to a total knee arthroplasty. Mean age at the time of revision surgery was 61.8 yr and 13 (59%) patients were male. Mean time to revision surgery from the primary procedure was 3.0 yr (range 0.6–6.2 yr). The commonest reasons for revision were aseptic loosening of the femoral (n=9) or tibial component (n=2), and undiagnosed (n=5) or patellofemoral pain (n=2). All patients were revised to a cemented total knee arthroplasty with most not requiring bone grafts. During follow-up (range 0.5–4.5 yr) no further surgery was performed in the 22 patients. In addition, there were no major postoperative complications and no evidence of radiological failure. Discussion. The present study demonstrates most failures of the Oxford unicompartmental knee arthroplasty occur within three to four years following the index procedure and are due to aseptic component loosening. These findings are consistent with other published reports regarding the early failure of this particular prosthesis. The short-term outcome following revision surgery appears to be good, however longer follow-up periods are required to determine if these good results continue

Aim. The purpose of this study was to analyze the patellofemoral kinematics in neglected adult developmental dysplasia of the hip patients with patellofemoral symptoms and tried to clarify the affect of the severity of dislocation, the amount of limb length discrepancy, the deviation of mechanical axis and the changes in femoral anteversion on patellofemoral alignment. Methods. The dynamic patellofemoral CT results of 39 patients with DDH suffering from knee pain were reviewed. The mean age was 40.07 (range: 22–61). 14 of them were bilateral and 25 were unilateral neglected DDH patients. The CT results of 12 patients suffering from unilateral patellofemoral pain following the treatment of locked intramedullary nailing was taken as control group. In this patients atraumatic and asymptomatic normal site was taken as control group. Results. In unilateral neglected DDH patients there was significantly higher medial patellar displacement in 0, 15, 30, 60 degrees flexion in the knee at the site of dislocation. Again in uninvolved site medial patellar displacement in 15, 30, 60 degrees flexion was higher with respect to control group. In the involved extremity the PTA angle in 0, 15, 30, 60 degrees flexion were significantly higher than in control group. This increase in PTA angle corresponding to medial patellar tilt was observed only in involved extremity. In the knees of patients with bilateral DDH there was significant medial patellar displacement in every flexion degrees with respect to control group. Besides in bilateral DDH patients, the PTA angle in 15, 30, 60 degrees flexion were significantly higher than control group corresponding to medial patellar tilt. The amount of leg length discrepancy and the severity of dislocation as well as mechanical axis deviation were not affecting the patellofemoral parameters in both unilateral and bilateral DDH patients. Conclusion. Both in unilateral and bilateral DDH patients there are major changes in patellar tracking on femur during knee flexion. Increased medial shift and medial patellar tilt were seen in these patient groups. The neglected DDH patients suffering from knee pain should be analyzed not only for tibiofemoral abnormalities but also for patellofemoral malignment