There is conflicting evidence about the merits of mobile bearings in total knee replacement, partly because most randomised controlled trials (RCTs) have not been adequately powered. We report the results of a multicentre RCT of mobile versus fixed bearings. This was part of the knee arthroplasty trial (KAT), where 539 patients were randomly allocated to mobile or fixed bearings and analysed on an intention-to-treat basis. The primary outcome measure was the Oxford Knee Score (OKS) plus secondary measures including Short Form-12, EuroQol EQ-5D, costs, cost-effectiveness and need for further surgery.

There was no significant difference between the groups pre-operatively: mean OKS was 17.18 (sd 7.60) in the mobile-bearing group and 16.49 (sd 7.40) in the fixed-bearing group. At five years mean OKS was 33.19 (sd 16.68) and 33.65 (sd 9.68), respectively. There was no significant difference between trial groups in OKS at five years (-1.12 (95% confidence interval -2.77 to 0.52) or any of the other outcome measures. Furthermore, there was no significant difference in the proportion of patients with knee-related re-operations or in total costs.

In this appropriately powered RCT, over the first five years after total knee replacement functional outcomes, re-operation rates and healthcare costs appear to be the same irrespective of whether a mobile or fixed bearing is used.

Cite this article: Bone Joint J 2013;95-B:486–92.

We report a prospective study of the feasibility of employing specially trained physiotherapists to screen neonates for congenital dislocation of the hip. During ten years 42,241 babies were screened, using clinical tests; 255 were diagnosed and treated by a Pavlik harness. In the same period 13 children presented late with congenital dislocation of the hip which had not been detected by the screening programme.

Two cases of delayed median nerve division after laceration of the wrist by glass are described. In both there was no neurological damage at the time of the original injury. However, retained fragments of glass were subsequently responsible for division of the median nerve in both cases and of the surrounding tendons in one. Radiographs were an important diagnostic aid in treating the delayed injury.

A 21-year-old female athlete presented with bilateral lumps in her calves which became painful on exercise. Exploration revealed entrapment of the superficial peroneal nerves. Her symptoms were relieved by fasciectomy.

Despite widespread use of gentamicin beads in the treatment of chronic infections of bone and soft tissue, no serious complications have been reported. This report describes a rupture of the femoral vein which occurred during the attempted removal of a chain of beads after radical excision of a chronically discharging Girdlestone arthroplasty. The patient later had a disarticulation at the hip. In the light of our experience with this and other cases we offer some suggestions as to the positioning of gentamicin beads, as well as the timing and method of their extraction.

Fracture separation of the capital femoral epiphysis occurring during attempted closed reduction of a traumatic dislocation of the hip is described in two adolescents. Although this complication is extremely rare, the prognosis of fracture separation with dislocation of the epiphysis is known to be poor. Avascular necrosis subsequently developed in both cases. The importance of gentle manipulative reduction under general anaesthesia with complete muscle relaxation is emphasised.