The Posterior Condylar Offset Ratio.

INTRODUCTION: Posterior Condylar Offset is an area of interest in knee arthroplasty research and clinical outcome. The aim of the study is to define a quantifiable Posterior Condylar Offset Ratio, a normal value for this ratio and to confirm its reproducibility on pre-operative radiographs. METHOD: We propose a new Posterior Condylar Offset Ratio which is defined as the maximal thickness of the posterior condyle projecting posteriorly to a straight line drawn as the extension of the posterior femoral shaft cortex, divided by the maximal thickness of the posterior condyle projecting posterior to a straight line drawn as the extension of the anterior femoral shaft cortex on a true lateral radiograph of the distal quarter of the femur. We have measured this on 100 true lateral radiographs (50 females, 50 males, and mean age 65 years). RESULTS: The mean ratio was 0.44 (SD 0.02) and was shown to have good reproducibility (intra-observer error 0.899 and inter-observer error 0.882. The ratio was also very consistent between male and female patients (0.44 (SD 0.02) for the males and 0.45 (SD 0.02) for the females). Adjusting the ratio for reported posterior condyle articular cartilage thickness increased the ratio to 0.47 (SD 0.02). CONCLUSION: We suggest our Posterior Condylar Offset Ratio is a useful tool to aid further research in this area of knee arthroplasty and propose a normal value of 0.44 on radiographs and 0.47 on post-operative knee arthroplasty radiographs.

Managing shoulder pain in general practice - assessment, imaging and referral.

BACKGROUND: A case review was carried out on 112 cases of shoulder pain, referred for specialist attention. The general practitioner referral letter offered a diagnosis in 40% (45/112) of cases with 89% (40/45) of these concurring with the diagnosis made by the orthopaedic surgeon. Shoulder ultrasound had been ordered for 95/112 (85%) patients with 71/112 (63%) being combined with plain radiology. OBJECTIVE: This article presents findings of a case review examining the management of shoulder pain in general practice. DISCUSSION: The assessment of shoulder presentation suggests a lack of confidence by the referring practitioner due to the reliance on diagnostic ultrasound. Such practice can be unnecessarily expensive and would benefit from the establishment of guidelines for what imaging best suits the presenting complaint.