Early Results of Our International, Multicenter, Multisurgeon, Double-Blinded, Prospective, Randomized, Controlled Trial Comparing Metal-on-Metal With Ceramic-on-Metal in Total Hip Arthroplasty.

BACKGROUND: The aim of our prospective, multicenter, randomized, controlled trial (titled M2A-38 Ceramic-on-Metal RCT, NCT00754520) is to demonstrate noninferiority of a ceramic-on-metal (CoM) articulation compared with metal-on-metal (MoM) in total hip arthroplasty. The study arms are at 8 years since implantation, with metal ion and functional score analysis at 5 years. METHODS: We recruited 211 patients between 2009 and 2011. The patients were randomized to ceramic or metal. A cohort of these patients had whole blood metal ions performed yearly, and all patients underwent annual radiographic and clinical outcome assessment. All revisions were recorded and some explants were analyzed. Recruitment ceased earlier than planned owing to concerns raised with failure of MoM implants. RESULTS: No significant difference was seen in patient demographics, radiographic parameters, or functional outcomes at any time point. Lower cobalt ion levels were seen in the CoM group (P < .01) at all time points. Chromium levels were significantly lower in the CoM group up to 3 years, but raised at 5 years. There were slightly fewer revisions for adverse reaction to metal debris in the CoM group. Explant analysis suggested a different wear pattern to those seen in the MoM group. CONCLUSION: The results demonstrated that the CoM articulation behaved the same as the MoM in terms of functional outcome and radiographic parameters. The CoM coupling also demonstrates raised metal ions beyond 3 years and increasing revisions for adverse reaction to metal debris. It remains difficult to see a clinical application for CoM and further exploration or use is not warranted.

Early MRI diagnosis and non-surgical management of spontaneous osteonecrosis of the knee.

Spontaneous osteonecrosis of the knee (SONK) is generally associated with a poor prognosis but the outcome depends on the clinical and radiological stage at which the patients present. The earliest stage of this condition does not necessarily progress in every patient, but discriminatory radiological information is lacking in order to differentiate these patients so that unnecessary surgical intervention can be avoided. We describe 20 sequential cases of early SONK diagnosed by magnetic resonance imaging (MRI) in which non-operative management led to the spontaneous resolution of symptoms and MRI changes. Our data was compared to published series in order to derive more accurate prognostic criteria that may then be used to determine appropriate management. Average age of patients was 52 years (42-64). All patients' symptoms resolved with conservative treatment at an average of 4.8 (3-8) months after symptoms began. All MRIs returned to normal. MRI prognostic criteria that appear to indicate a benign course are the absence of focal epiphyseal contour depression and the absence of lines of low signal intensity deep in the condyles. The presence of high signal T2 rim and a length >14 mm and depth >4 mm of the low signal T2 lesion did not necessarily indicate a bad prognosis. Early SONK in this group of patients resolves without surgical intervention. The group is typically middle aged, present with acute focal pain in the knee, have no secondary cause of osteonecrosis, have minimal or no changes on plain radiographs, and have focal changes on MRI. Recognition of this group using MRI identifies the earliest changes in SONK and gives prognostic information that avoids inappropriate surgical intervention.

Undisplaced intracapsular hip fractures: results of internal fixation in 375 patients.

Three hundred seventy-five patients with an undisplaced intracapsular proximal femoral fracture were treated with internal fixation. Nonunion occurred in 24 patients (6.4%) and avascular necrosis occurred in 15 patients (4.0%). Reoperation with an arthroplasty was required in 29 patients (7.7%). The age, walking ability of the patient, and degree of impaction seen on the anteroposterior radiograph or angulation seen on the lateral radiographs were of statistical significance in predicting fracture healing complications. The results for this series of patients were compared with the results in published reports identified by a comprehensive literature search. Summation of the results indicated that the overall risk of redisplacement or nonunion of the fracture was 4.3% (95% confidence interval, 3.4%-5.3%) with internal fixation of an undisplaced intracapsular fracture. For conservative treatment, the failure rate was 19.6% (95% confidence interval, 17.2%-22.1%). The incidence of avascular necrosis with internal fixation at 1 year was 2.2% (95% confidence interval, 1.6%-2.9%) compared with 2.8% (95% confidence interval, 1.9%-4.0%) with nonoperative treatment. Internal fixation is recommended for the treatment of undisplaced intracapsular hip fractures.

Orthopaedic Specialist Registrar training and attitudes to spine surgery in the United Kingdom: reasons for poor recruitment and suggestions for improvement.

In order to improve the provision of spinal surgery in the United Kingdom, the number of Specialist Spinal Surgeons and Surgeons with an Interest in Spinal Surgery needs to increase by 25% from the existing 175 surgeons. A survey of Specialist Orthopaedic Registrars was performed, which quantifies the predicted shortfall in the number intending to practise spinal surgery. The attitudes towards and perceptions of this field were obtained to identify factors that could be discouraging an interest in spine surgery.