Distal Extension of the Anterior Approach to the Hip Using the Femoral Interbundle Technique: Surgical Technique and Case Series.

BACKGROUND: The direct anterior approach (DAA) is becoming more popular as the standard surgical approach for primary total hip arthroplasty. However, it has been associated with an increased incidence of intraoperative femoral fractures in particular during the learning curve. Distal extension of the approach may be needed in case of intraoperative complications. The aim of the present study is to describe the distal extension of the DAA using the femoral interbundle technique. METHODS: A stepwise approach based on a cadaveric study to extend the DAA distally is presented. The interval between the neurovascular bundles running to the vastus lateralis is used to gain access to the femur. Clinical and electromyography results of 5 patients undergoing a revision of the femoral component through an extended anterior approach are reported. RESULTS: In 2 cases, the proximal bundle was exposed whereas in 3 cases the interval between the proximal and distal bundle was developed and cerclage wires were applied around the isthmus of the femur. All fractures had healed at 6 months of follow-up. Four cases had a normal electromyography, and 1 case demonstrated a neuropraxia of a branch to the vastus lateralis. All cases had a 5/5 extension power of the quadriceps muscle clinically. CONCLUSION: The interbundle technique is an alternative way to gain additional exposure of the femur during the DAA and is based on precise knowledge of the periarticular neurovascular structures. This approach can be helpful to safely deal with intraoperative complications such as fractures requiring proximal femoral cerclage wiring during the anterior approach.

Distal Extension of the Direct Anterior Approach to the Hip: A Cadaveric Feasibility Study.

BACKGROUND: The direct anterior approach (DAA) is becoming more popular as the standard surgical approach for primary total hip arthroplasty. However, femoral complications of up to 2.8% have been reported. Therefore, it is important for surgeons to understand the periarticular neurovascular anatomy in order to safely deal with intraoperative complications. METHODS: Anatomic dissections were performed on 20 cadaveric hips. The neurovascular structures anterior to the femur and distal to the intertrochanteric line were dissected and its position was described in relation to anatomic landmarks easily identified through the DAA: anterior superior iliac spine (ASIS), the insertion of the gluteus minimus (GM), and the lesser trochanter (LT). RESULTS: Two clearly distinguishable neurovascular bundles running to the vastus lateralis were seen in 17 of 20 specimens. The average distances to the landmarks were as follows: ASIS-1st bundle = 12.3 cm (range, 9.7-14.5); GM-1st bundle = 3.2 cm (range, 2.2-4); LT-1st bundle = 1.6 cm (range, 0.7-2.8); 1st bundle-2nd bundle = 3.3 cm (range, 1.8-6.1). CONCLUSION: A consistent pattern of 2 clearly distinguishable neurovascular bundles was seen in 85% of the specimens. Knowledge of the position of these neurovascular bundles in relation to the anatomic landmarks makes distal femoral extension of the DAA feasible. Further clinical studies are needed to confirm the safety of the extensile anterior approach.