Skyline patellofemoral radiographs can only exclude late stage degenerative changes.

Accurate preoperative assessment of the patellofemoral joint is especially important in compartment specific knee arthritis. This study aims to show the actual intraoperative grade of patellofemoral cartilage damage that may be reliably detected or excluded by preoperative standard radiographic views. 100 consecutive knees awaiting arthroplasty underwent preoperative lateral and skyline radiographs and were scored using the Ahlback score. Intraoperative cartilage damage was assessed using the Collins score. The sensitivity and specificity were calculated for each grade of cartilage damage. Preoperative anterior knee pain and function were assessed and correlated to the degree of cartilage damage. The lateral radiograph shows poor sensitivity for all grades of disease (0.05-0.23). The skyline shows good sensitivity for grade 4 (large full thickness) damage (0.90) but decreases substantially for grades 1-3 (0.19-0.46). Significantly more people with skyline radiograph joint space narrowing complained of anterior knee pain than those with a normal radiograph (p<0.001). There was only a poor correlation between preoperative anterior pain and intraoperative patellofemoral cartilage damage (r=0.24). The lateral radiograph cannot exclude even large areas of full thickness cartilage damage whereas a normal skyline radiograph can reliably exclude significant (grade 4) patellofemoral disease and should be used in addition to the lateral view.

The implications of damage to the lateral femoral condyle on medial unicompartmental knee replacement.

With medial unicompartmental osteoarthritis (OA) there is occasionally a full-thickness ulcer of the cartilage on the medial side of the lateral femoral condyle. It is not clear whether this should be considered a contraindication to unicompartmental knee replacement (UKR). The aim of this study was to determine why these ulcers occur, and whether they compromise the outcome of UKR. Case studies of knees with medial OA suggest that cartilage lesions on the medial side of the lateral condyle are caused by impingement on the lateral tibial spine as a result of the varus deformity and tibial subluxation. Following UKR the varus and the subluxation are corrected, so that impingement is prevented and the damaged part of the lateral femoral condyle is not transmitting load. An illustrative case report is presented. Out of 769 knees with OA of the medial compartment treated with the Oxford UKR, 59 (7.7%) had partial-thickness cartilage loss and 20 (2.6%) had a full-thickness cartilage deficit on the medial side of the lateral condyle. The mean Oxford Knee Score (OKS) at the last follow-up at a mean of four years was 41.9 (13 to 48) in those with partial-thickness cartilage loss and 41.0 (20 to 48) in those with full-thickness loss. In those with normal or superficially damaged cartilage the mean was 39.5 (5 to 48) and 39.7 (8 to 48), respectively. There were no statistically significant differences between the pre-operative OKS, the final review OKS or of change in the score in the various groups. We conclude that in medial compartment OA, damage to the medial side of the lateral femoral condyle is caused by impingement on the tibial spine and should not be considered a contraindication to an Oxford UKR, even if there is extensive full-thickness ulceration of the cartilage.

Radiological features of osteoarthritis of the acromiclavicular joint and its association with clinical symptoms.

PURPOSE: To determine whether increasing age is associated with increased radiological features of osteoarthritis of the acromioclavicular joint (ACJ) in a general population, and whether clinical symptoms correlate with radiological features. METHODS: Anteroposterior and axillary shoulder radiographs of 240 patients aged 20 to 80 years were randomly selected. The presence of stigmata of osteoarthritis of the ACJ including sclerosis, cysts, lysis, and osteophytes were recorded, and the width of the ACJ was measured. To determine the correlation between clinical symptoms and radiological features, the same radiological features were assessed for 100 further patients who had undergone either arthroscopic subacromial decompression (ASD) alone (n=50) or ASD plus ACJ excision (n=50, age-matched controls) based on clinical examination. RESULTS: Radiological features of osteoarthritis of the ACJ increased significantly with increasing age but were not related to gender or the side affected. Of the 10 features, only medial acromial sclerosis and superior clavicular osteophytes were more prevalent in patients with ASD plus ACJ excision than in those with ASD alone (p=0.016). The sensitivity, specificity, positive and negative predictive values of these features were poor. Therefore, clinical symptoms were not associated with radiological features of osteoarthritis of the ACJ. CONCLUSION: Radiological features should only be used as an adjunct in the decision to excise the ACJ. A thorough clinical examination is crucial in the assessment of ACJ pathology.