Trunnionosis in modular hip arthroplasty has recently been recognised to be clinically important. Gaining an understanding of how the material interface at the head-trunnion affects the tribology at the modular junctions has current clinical implications as well as an implication on future implant selection and material choice. This matched-cohort study aims to compare tribocorrosion between ceramic and cobalt-chromium trunnions and to investigate other factors that contribute to the difference in tribocorrosion if present.

All hip prostheses retrieved between 1999 and 2015 at one centre were reviewed. Fifty two ceramic heads were retrieved, and these were matched to a cobalt-chromium cohort according to taper design, head size, neck length and implantation time in that order. The two cohorts were similar in male:female ratio (p=0.32) and body mass index (p=0.15) though the ceramic group was younger than the cobalt-chromium group (56.6 (+/−)13.5 years for ceramic group vs 66.3 (+/−14.4) years for cobalt-chromium group; p=0.001). There was no significant difference in the reasons for revision between the two groups (p=0.42). The femoral head trunnions were examined by two independent observers using a previously published 4-point scoring technique. The trunnions were divided into three zones: apex, middle and base. The observers were blinded to clinical and manufacturing data where possible.

Ceramic head trunnions demonstrated a lower median fretting and corrosion score at the base zone (p<0.001), middle zone (p<0.001) and in the combined score (p<0.001). In a subgroup analysis by head size, ceramic heads had a lower fretting and corrosion score at 28mm head diameter (p<0.001). Within the ceramic group, taper design had a significant effect on fretting and corrosion in the apex zone (p=0.04). Taper design also had a similar effect in the cobalt-chromium group in the apex zone (p=0.03). For the ceramic trunnions, the largest effect was contributed by the difference between the 11/13 taper and the 12/14 taper. For the cobalt-chromium trunnions, the largest effect was contributed by the difference between the 5 degree 38′ 37″ taper and type 1 taper.

Ceramic head trunnions showed a significantly lower fretting and corrosion score as compared to cobalt-chromium trunnions. Ceramic heads had a lower score than cobalt-chromium heads at 28mm head diameter. Taper design had an effect on fretting and corrosion within each cohort.

Introduction: In 1979 Linburg and Comstock described anomalous tendon slips between flexor pollicus longus and the flexor digitorum profundus in 31% of individuals (Linburg, Comstock; J Hand surg 1997, Jan). The purpose of this study is to find out the incidence of Linburg-Comstock Syndrome in the British population.

Methods: A clinical examination of the hands of healthy volunteers, including office workers and medical professionals was carried out. It was determined if flexion of the thumb causes concomitant flexion of index or/and middle finger. Additionally, pain on passive extension of the fingers was also documented.

Summary of Results: 70 volunteers were included, the test for Linburg-Comstock syndrome was positive in 55% of people who had concomitant flexion of the fingers with the thumb and pain in the wrist with passive extension. In 70% of people just concomitant finger flexion was seen. In 10 cadaveric dissections no connecting tendon slips were found but one fibrinous connection between FPL and FDP was noted.

Conclusion: Our study shows that the incidence of Linburg –Comstock Syndrome is much higher than previously thought based on the clinical examination. However cadaveric dissections did not confirm a distinct structural connection except in one case where there was a fibrinous connection. It is likely that at least in some cases it is a acquired anomaly in response to repeated use/overuse of thumb and index fingers.

Introduction Unicompartmental knee arthroplasty (UKA) is well established in the treatment of OA of the knee, but has not been performed in large numbers compared with total knee arthroplasty. However, with the development of minimally invasive surgery, numbers of procedures are increasing rapidly. This study examines the results of minimally invasive UKA performed by one surgeon since august 1998.

Methods A consecutive series of 388 knees in 360 patients operated between August 1988 and February 2003 were evaluated using a prospective database. All surgeries were performed by the senior author using a minimally invasive technique in a day surgery unit. General anaesthesia was used in all cases with local anaesthesia intra-operatively, combined with an anaesthetic infusion pump. No patient received parenteral narcotics. Ninety-seven percent were medial and three percent were lateral arthroplasties.

Results Post-operatively no patients were lost to follow-up which ranged from two months to 4.5 years. Average age was 66 years. The average IKS score improved from 75 to 158 post-operatively. Most patients retained their pre-operative range of motion which averaged 120°. Average length of stay was 1.57 days with 41% of patients discharged the same day. There were five failures, due in part to osteoporosis and overcorretion. These were revised successfully to a ‘primary’ type knee prosthesis. Satisfaction rate subjectively was 98%.

Conclusions Mid term results of UKA using the Repicci technique of minimally invasive surgery with rapid mobilisation and early discharge has ahcieved excellent results for unicompartmental OA of the knee. The procedure is better tolerated with a low complication rate and higher patient satisfaction than total knee replacement in this gourp of patients.

Aims: To compare the outcome of PFN and DHS þxation of unstable proximal femoral fractures. Methods: The authors conducted a prospective study of 70 consecutive patients with acute AO/ASIF 31-A2 and A3 and complex intertrochantaric fractures. Patients underwent either PFN or DHS fracture þxation depending on surgeon experience and preference. Patients were all followed up for 6months. The main outcome measures were operative blood loss, length of hospital stay, radiographic fracture union, complication rates, independent mobility and residual hip pain at 6 months. Results: The two groups exhibited similar demographic characteristics, premorbid mobility and fracture severity. Operation duration was similar in the two groups although blood loss was signiþcantly less in the PFN group (PFN 275mls; DHS 475mls). There was a signiþcant difference in length of hospital stay (PFN 14 days; DHS 22 days). Three patients in the DHS group suffered failure of þxation, two of them had screw cut out. There were no implant failures or failure of þxation in the PFN group. At 6 months both groups showed similar mobility. Persistent severe hip pain at 6 months was PFN 3% and DHS 9%. Conclusion: The proximal femoral nail may be used successfully in the þxation of unstable femoral fractures with similar results to the DHS for mobility at 6 months. There may be advantages over the DHS in terms of reduced blood loss, shorter hospital stay and less morbidity.