Abstract
Introduction
The debate regarding the importance of preserving the blood supply to the femoral head (FH) and neck during hip resurfacing arthroplasty (HRA) is ongoing. Several surgeons continue to advocate for the preservation of the blood supply to the resurfaced heads for both the current HRA techniques and more biologic approaches for FH resurfacing. Despite alternative blood-preserving approaches for HRA, many surgeons continue to use the posterior approach (PA) due to personal preference and comfort. It is commonly accepted that the PA inevitably damages the deep branch of the medial femoral circumflex artery (MFCA). This study seeks to evaluate and measure the anatomical course of the ascending and deep branch of the MFCA to better describe the area in danger during the posterior approach.
Methods
In 20 fresh-frozen cadaveric hips, we cannulated the MFCA and injected a urethane compound. The Kocher-Langenbeck approach was used in all specimens. The deep branch of the MFCA was identified at the proximal border of the QF and measurements were taken. The QF was incised medially and elevated laterally, maintaining the relationship of the ascending branch and QF, and distances from the lesser trochanter were measured. The deep branch was dissected and followed to its capsular insertion to assess the course and relation to the obturatur externus (OE) tendon and the conjoint tendon (CT) of the short external rotators.
Results
Gross dissection revealed that the transition point from transverse to ascending branch of the MFCA at the anterior surface of the QF was at an average distance of 2.2 cm (range 2–2.3 cm) proximal and 1.2 cm (range 0.5–1.9 cm) medial to the lesser trochanter. The ascending branch runs caudally within fat tissue that divides the QF and OE at an average distance of 1.5 cm (range 0.7–2.3 cm) from the QF greater trochanter insertion. At the superior border of the QF, the MFCA continues as the deep branch posterior to the OE tendon at an average distance of 1.3 cm (range 0.6–1.9 cm) from the OE femoral insertion. The deep branch was noted to enter the capsule at an average distance of 0.3 cm (range 0–0.5 cm) from the distal border of the CT and 1.2 cm (range 0.6–1.9 cm) from the CT femoral insertion.
Discussion and Conclusion
The ascending branch of the MFCA runs in the anterior surface of the QF at a distance of 1.5 cm from the femoral insertion. When the QF myotomy is performed, commonly 0.5–0.8 cm from the insertion to the femur, the vessel get disrupted or stays medial to the myotomy and can stretch/disrupt when the femur is dislocated and translated anteriorly. Tenotomies of the OE and CT should stay at least 1.5 cm from the femoral insertion to preserve the deep branch of the MFCA. This study provides unreported topographic anatomy of the ascending and deep branch of the MFCA, which can help develop an improved blood-preserving posterior approach for HRA.
