Avulsion fractures of the tip of the olecranon are a common traumatic injury. Kirshner-wire fixation (1.6mm) with a figure of eight tension band wire (1.25mm) remains the most popular technique. Hardware removal mat be required in up to 80% of cases. Modern suture materials have very high tensile strength coupled with excellent usability. In this study we compare a repair using 1.6mm k-wires with a 1.25mm surgical steel, against a repair that uses two strands of 2 fibrewire. Twelve Pairs of cadaveric arms were harvested. A standard olecranon osteotomy was performed to mimic an avulsion fracture. In each pair one was fixed using standard technique, 2 × 1.6mm transcortical ?-wire plus figure of 8 loop of 1.25mm wire. The other fixed with the same ?-wires with a tension band suture of 2.0 fibrewire (two loops, one figure of 8 and one simple loop). The triceps tendon was cyclically loaded (10-120 Newtons) to simulate full active motion 2200 cycles. Fracture gap was measured with the ‘Smart Capture’ motion analysis system. The arm was fixed at 90 degrees and triceps tendon was loaded until fixation failure, ultimate load to failure and mode of failure was noted. The average gap formation at the fracture site for the suture group was 0.91mm, in the wire group 0.96mm, no specimen in either group produced a significant gap after cyclical loading. Mean load to failure for the suture group was 1069 Newtons (SD=120N) and in the wire group 820 Newtons (SD=235N). Both types of fixation allow full early mobilisation without gap formation. The Suture group has a significantly higher load to failure (p=0.002, t-test). Tension Band suture allows a lower profile fixation, potentially reducing the frequency of wound complications and hardware removal.
In relation to the conduct of this study, one or more of the authors is in receipt of a research grant from a non-commercial source.
Reported rates of dislocation after primary and revision total hip replacement (THR) vary widely, whereas subluxation after THR is not commonly reported. Importantly, it is now recognised that reported dislocation rates are likely to be an underestimate of the true dislocation rate. The primary aim of this study was to develop and validate a Patient Hip Instability Questionnaire and subsequently to use this questionnaire to determine the incidence of dislocation, subluxation and symptoms due to hip instability following primary and revision THR. In addition the associated costs, morbidity, disability and effects on health-related quality of life were examined. A retrospective review of dislocation rates from 1996 to 1998 identified problems in determining the true dislocation rate from standard hospital and database records. Therefore, a patient-completed Hip Instability Questionnaire was developed and validated to monitor dislocation and subluxation rates. This was then mailed to patients three and 12 months following primary or revision THR. All dislocations were then confirmed by telephone interview and radiographs. Telephone interviews and patient completion of the SF-36 questionnaire were used to assess morbidity, disability and quality of life. Costs of treating patients with hip dislocation were also determined. The response rate to the mailed questionnaire was greater than 95%. The questionnaire was shown to be a valid measure of the true rate of dislocation following THR and confirmed the inaccuracies in previous methods of determining dislocation rate based on hospital and database records. Using this questionnaire, the rate of subluxation was higher than previously reported and the significant morbidity and health care costs associated with with this complication were identified. The use of this questionnaire will allow better assessment of morbidity and costs due to complications following THR.