Outcome-based commissioning of knee arthroplasty in the NHS: system error in a national monitoring programme and the unintended consequences on achieving the Best Practice Tariff.

AIMS: Our unit was identified as a negative outlier in the national patient-reported outcome measures (PROMs) programme, which has significant funding implications. As a centre that carries out a high volume of unicompartmental knee arthroplasty (UKA), our objectives were: 1) to determine whether the PROMs programme included primary UKA when calculating the gain in Oxford Knee Score (OKS); and 2) to determine the impact of excluding primary UKA on calculated OKS gains for primary knee arthroplasty. MATERIALS AND METHODS: National PROMs data from England (2012 to 2016) were analyzed. Inclusion of UKA cases in the national PROMs programme was determined using clinical codes. Local OKS gain was calculated for UKA and TKA and compared with the published PROMs results for 2012/13. RESULTS: Use of the recommended codes for primary UKA excluded 99.6% of UKAs locally and 97% nationally from PROMs programme analysis. Inclusion of primary UKAs in PROMs analysis improved our OKS gain from 15.1 (below average) to 16.3 (above average) for 2012/13 for primary knee arthroplasty. CONCLUSION: Exclusion of UKA patients from the PROMs programme is a nationwide issue that potentially introduces bias when comparing OKS gain between centres. Where commissioning decisions are based on routinely collected data, it is imperative that the underlying methodology is appropriate to generate valid results.

A survival analysis of 1084 knees of the Oxford unicompartmental knee arthroplasty: a comparison between consultant and trainee surgeons.

AIMS: The aim of this to study was to compare the previously unreported long-term survival outcome of the Oxford medial unicompartmental knee arthroplasty (UKA) performed by trainee surgeons and consultants. PATIENTS AND METHODS: We therefore identified a previously unreported cohort of 1084 knees in 947 patients who had a UKA inserted for anteromedial knee arthritis by consultants and surgeons in training, at a tertiary arthroplasty centre and performed survival analysis on the group with revision as the endpoint. RESULTS: The ten-year cumulative survival rate for revision or exchange of any part of the prosthetic components was 93.2% (95% confidence interval (CI) 86.1 to 100, number at risk 45). Consultant surgeons had a nine-year cumulative survival rate of 93.9% (95% CI 90.2 to 97.6, number at risk 16). Trainee surgeons had a cumulative nine-year survival rate of 93.0% (95% CI 90.3 to 95.7, number at risk 35). Although there was no differences in implant survival between consultants and trainees (p = 0.30), there was a difference in failure pattern whereby all re-operations performed for bearing dislocation (n = 7), occurred in the trainee group. This accounted for 0.6% of the entire cohort and 15% of the re-operations. CONCLUSION: This is the largest single series of the Oxford UKA ever reported and demonstrates that good results can be achieved by a heterogeneous group of surgeons, including trainees, if performed within a high-volume centre with considerable experience with the procedure. Cite this article: Bone Joint J 2016;(10 Suppl B):22-7.

The clinical symptom profile of early radiographic knee arthritis: a pain and function comparison with advanced disease.

PURPOSE: Early knee OA is a significant problem that can be disabling. The purpose of this study was to understand the symptomatic profile of patients with early knee OA when compared to those with end-stage knee OA. METHODS: A cross-sectional case control study design was used to compare those with early structural change to those with advanced structural change. In total, 100 consecutive patients with early radiographic knee OA presenting to the knee service outpatient clinic from December 2010 to August 2011 were prospectively identified on the basis of their radiographic changes. All met the symptomatic and radiological diagnostic criteria of early knee OA as defined by Luyten et al. They were compared with 200 knees with full thickness anteromedial knee OA and 200 knees with full thickness tricompartmental knee OA for their demographic, pain and functional profile. RESULTS: Patients with early knee OA were younger than those with full thickness disease. However, 78% of individual patients with early radiographic OA had pain and function scores equal to individual patients presenting for UKA, whilst 74% of individual patients with early radiographic OA had pain and function scores that are equal to or worse than individual patients presenting for TKA. CONCLUSIONS: Patients with early radiographic knee OA demonstrate considerable overlap in the severity of their symptoms with those demonstrating end-stage structural changes within the knee. Patients with early structural changes of arthritis should not be assumed by clinicians to have mild disease. In many cases, their symptoms are as bad as those with end-stage structural changes. This work will help clinicians to identify and categorise those with early arthritis and thereby assist in guiding appropriate treatments.

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.

Displacement of the common peroneal nerve in posterolateral corner injuries of the knee.

We reviewed the relationship between the pattern of damage to the posterolateral corner of the knee and the position of the common peroneal nerve in 54 consecutive patients with posterolateral corner disruption requiring surgery. We found that 16 of the 18 patients with biceps avulsions or avulsion-fracture of the fibular head had a displaced common peroneal nerve. The nerve was pulled anteriorly with the biceps tendon. None of the 34 proximal injuries resulted in an abnormal nerve position. Whenever bone or soft-tissue avulsion from the fibular head is suspected, the surgeon should expect an abnormal position of the common peroneal nerve and appreciate the increased risk of iatrogenic damage.