We measured and compared critical parameters on antero-posterior radiographs from 28 patients who had undergone hybrid hip replacement (CPS/EPF), with 28 patients who had undergone cemented hip resurfacing (Cormet). All operations were performed by a single surgeon or under his supervision. We measured the femoral offset, acetabular offset, cup height and leg length on pre and post operative radiographs. The mean difference in femoral offset post-operatively was 3.52 mm (95% CI: -1.10 to 8.14 mm) in the hybrid group and -1.30 mm (95%CI: -2.88 to 0.29 mm) in the resurfacing group. Using the independent sample t test (two-tailed), the difference between these means was significant, test statistic t 2.025, p<0.05. This suggests that resurfacing restored the femoral offset more accurately than hybrid hip replacement. The mean difference in leg length post-operatively was 11.91 mm (95% CI: 8.21 to 15.62 mm) in the hybrid group and 4.87 mm (95% CI: 3.32 to 6.42 mm) in the resurfacing group. Using the independent sample t test (two-tailed), the difference between the means was significant, test statistic t 3.597, p<0.001. This suggests that resurfacing produced less change in leg length post-operatively than hybrid hip replacement. We found no statistically significant difference in ideal pre and post operative centre of rotation in the two groups. Proximal femoral anatomy was restored during hip resurfacing by resecting bone of a thickness determined by corresponding preoperative templating and implant thickness rather than relying on placement of the cutting ring at the head-neck junction. No femoral neck fractures occurred in the resurfacing group.

The treatment of Legg-Calvé-Perthes disease remains controversial. The aim of this survey was to ascertain the current management strategies of this condition amongst UK paediatric orthopaedic surgeons, with particular regard to containment procedures in the fragmentation phase. Questionnaires were distributed at the January 2006 meeting of the British Society for Children’s Orthopaedic Surgery (BSCOS) and was posted to all absent members. The results showed a great deal of variability not only in the treatment of Perthes disease, but also in the decision-making processes. Consideration must now be given to a carefully constructed national multi-centre prospective randomised controlled study into the optimum management of this disease

Hindfoot deformities are often surgically corrected with calcaneal osteotomy. These are increasingly performed via a minimally invasive approach. Identifying a neurovascular “safe zone” for this approach is important in reducing iatrogenic injury. We aimed to identify a safe zone for minimally invasive calcaneal osteotomy without neurovascular injury. Three individuals independently assessed 100 con- secutive magnetic resonance imaging ankle studies. The distance of the medial neurovascular bundle from the level of the centre of the Achilles tendon insertion was measured. The points measured were centralised in three planes (axial, sagittal and coronal). The three sets of observations were statistically analysed with confidence intervals and intraclass correlation coefficient was calculated. The mean distance measured by the three observers were 22.91 mm (range 18.2-28.5 mm); 22.81 mm (range 18.7-26.7 mm); and 23.41 mm (range 19.2- 28.4 mm); overall mean 23.0 mm. The mean inter- observer variation was 1.1 mm. 95% confidence interval for observer 1 ranges from 22.45-23.25 mm, observer 2 ranges from 22.52-23.1 mm and observer 3 ranges from 22.97-23.65 mm. Overall 95% confidence interval ranges from 22.8-23.2 mm. Intraclass correlation coefficient for inter-observer reliability is 0.7, indicating strong agreement between the observers. This radiological study suggests an anatomical “safe zone” for minimally invasive medial calcaneal osteotomy is at least 18 mm (mean: 23 mm) from the level of insertion of the Achilles tendon. Individual variation between patients must be taken in to consideration during preoperative planning.