While an increasing amount of arthroplasty articles report comorbidity measures, none have been validated for outcomes. In this study, we compared commonly used International Classification of Diseases-based comorbidity measures with re-operation rates after total hip replacement (THR). Scores used included the Charlson, the Royal College of Surgeons Charlson, and the Elixhauser comorbidity score. We identified a nationwide cohort of 134 423 THRs from the Swedish Hip Arthroplasty Register. Re-operations were registered post-operatively for up to 12 years. The hazard ratio was estimated by Cox’s proportional hazards regression, and we used C-statistics to assess each measure’s ability to predict re-operation. Confounding variables were age, gender, type of implant fixation, hospital category, hospital implant volume and year of surgery.

In the first two years only the Elixhauser score showed any significant relationship with increased risk of re-operation, with increased scores for both one to two and three or more comorbidities. However, the predictive C-statistic in this period for the Elixhauser score was poor (0.52). None of the measures proved to be of any value between two and 12 years. They might be of value in large cohort or registry studies, but not for the individual patient.

Cite this article: Bone Joint J 2013;95-B:1184–91.

In a prospective randomised study 31 patients were allocated to either arthrodesis or Mayo resection of the first metatarsophalangeal joint as part of a total reconstruction of the rheumatoid forefoot. Of these, 29 were re-examined after a mean of 72 months (57 to 80), the Foot Function Index was scored and any deformity measured. Load distribution was analysed using a Fscan mat in 14 cases, and time and distance were measured in 12 of these patients using a 3D Motion system. We found excellent patient satisfaction and a significant, lasting reduction of the Foot Function Index, with no statistically significant differences between the groups. There were no significant differences in recurrence of the deformity, the need for special shoes, gait velocity, step length, plantar moment, mean pressure or the position of the centre of force under the forefoot. The cadence was higher and the stance phase shorter in the fusion group.

These results suggest that a Mayo resection may be an equally good option for managing the first metatarsophalangeal joint in reconstruction of the rheumatoid forefoot.

We analysed the axis of movement in the normal elbow during flexion in vivo using radiostereometric analysis (RSA). The results show an intraindividual variation in the inclination of the axis ranging from 2.1° to 14.3° in the frontal and from 1.6° to 9.8° in the horizontal plane analysed at 30° increments. The inclination of the mean axis of rotation varied within a range of 12.7° in the frontal and 4.6° in the horizontal plane. In both planes, the mean axes were located close to a line joining the centres of the trochlea and capitellum. The intra- and interindividual variations of the axes of flexion of the elbow were greater than previously reported. These factors should be considered in the development of elbow prostheses.

We conducted an epidemiological study of osteosarcoma in Sweden from 1971 to 1984 to investigate whether the typical features of the disease had changed. Of 294 osteosarcoma patients reviewed, 249 had primary skeletal tumours, and for these the mean annual incidence was 2.1 per million, without any clear trend over time. The mean male/female ratio for the period was 1.6 again with no consistent pattern over time; nor was there any significant change in the distribution of tumours according to location. The only feature which showed a significant change over the 14-year period was the mean age of the patients, being at its lowest (19 years) in 1972 and at its highest (40 years) in 1981. Excluding the 22 patients with craniofacial tumours, the remaining 227 also showed a significant increase in mean age. Analysis of the annual age distribution disclosed an increasing fraction of patients older than those in the classical age peak between 10 and 29 years. A large number of trials have shown improved survival in osteosarcoma over the last 15 years, which has been attributed mainly to adjuvant chemotherapy. The change we have observed in age distribution should also be taken into account in the evaluation of the results of treatment; it may be that older patients have a better prognosis.