Abstract
Introduction: The use of minimal incision THR is increasing. The purpose of this study is to determine the effects of a change in operative technique from a standard incision to a minimally invasive incision at primary THR on peri-operative blood loss, analgesia requirement, length of stay, and complication rate. Two consecutive groups are compared.
Materials and methods: All patients who underwent a primary THR (posterior approach) by the senior author during a 3month period before and after a change in technique from a standard to a minimal incision were identified. 202 patients were analysed: 105 standard incisions and 97 minimal incisions. A retrospective chart review was used to collect age, height, weight, BMI, diagnosis and length of stay for each patient. Estimated peri-operative blood loss in units of blood was calculated by a validated formula. Morphine usage by PCA in the first 24hours post-operatively was recorded. Complications were identified.
Results: There was no significant difference in the mean age, height, weight or BMI between the 2 groups. Predominant diagnosis was primary osteoarthritis. Mean wound length for the standard incision was 16.6cms. Mean wound length for the minimal incision was 11cms. There was no difference in length of stay, mean 5.4days. There was no difference in morphine usage by PCA in the first 24hours, mean 39.4mgs.
Average estimated peri-operative blood loss for the standard incision group was 3.45 units and for the minimal incision group was 3.05 units (statistically significant, p-value 0.039, 95%CI). One patient after minimal incision had a superficial wound infection, which responded to oral antibiotics. There was one dislocation (standard incision).
Conclusions: Peri-operative estimated blood loss was less with a minimal incision but there was no difference in length of stay or analgesia requirement. A prospective RCT is now underway to determine the clinical efficacy of minimally invasive THR.
The abstracts were prepared by Mr Peter Kay, Editorial Secretary. Correspondence should be addressed to British Hip Society, The Hip Centre, Wrightington Hospital, Appley Bridge, Wigan, Lancashire WN6 9EP.
