Soft tissue injury related to choice of entry point in antegrade femoral nailing: piriform fossa or greater trochanter tip

Intramedullary nailing through the piriform fossa results in some cases in loss of abduction strength and persistent pain. Nail insertion at the tip of the greater trochanter may be favourable. The aim of this study was to assess (possible) iatrogenic injury to the abductor and external rotator musculature, branches of the superior gluteal nerve and branches of the MFCA in relation to the two different entry points. In 10 fresh human cadaver femurs, five unreamed femoral nails (UFN) were inserted through the piriform fossa and five AO prototype nails (AFN) through the trochanteric tip. The iatrogenic injury at each nailing procedure was assessed. Various muscles and tendons, branches of the MFCA along with the hip joint capsule were injured or largely at risk during nail insertion through the piriform fossa. Most of these structures were not exposed during insertion through the trochanteric tip. The reported clinical morbidity after nailing through the piriform fossa may find its origin in direct soft tissue injury and may be reduced by choosing a lateral nail entry point.