Anatomic implications of lesser trochanterplasty

OBJECTIVE: The aim of this study was to measure the area of iliopsoas tendon attachment and the distance of sciatic nerve, medial circumflex femoral artery (MCFA) and quadratus muscle to lesser trochanter tip, before and after 5, 10, 15 mm depth excision of lesser trochanter. METHODS: A total 15 hips of 8 adult male cadavers were evaluated. Distances between lesser trochanter tip, sciatic nerve, the lower edge of quadratus muscle and MCFA; length and width of quadratus muscle insertion; area of iliopsoas muscle and quadratus muscle insertion was measured before and after sequential 5,10 and 15 mm depth trochanterplasties using 5 mm wide burr parallel to the posterior cortex. RESULTS: Each incremental 5 mm depth bone removal led to significant decrease of tendon area (p=0.001) at each stage. Mean decreases of iliopsoas tendon attachment area with incremental 5 mm burring were 22%±10 with 5 mm, 50%±13 with 10 mm, and 76% ±13 with 15 mm of burring. CONCLUSION: Up to 15 mm lesser trochanter removal did not result in complete detachment of the iliopsoas tendon. Lesser trochanter tip was detected at least 20 mm away from important anatomic structures including quadratus tendon, sciatic nerve, and the medial circumflex femoral artery.