In Situ Reduction and Fixation of the Anterior Medial Fenestration Approach for Femoral Head Fracture

Abstract

Objective: To investigate the feasibility and clinical application of the anterior medial fenestration approach in the treatment of Pipkin type I and II femoral head fractures.

Methods: The hips of two anti-corrosion adult specimens treated with formalin were dissected and the anatomical structures and directional characteristics of the anterior medial main muscles, ligaments, blood vessels, and nerves were observed. The anterior medial fenestration approach was performed on bilateral hips of four fresh frozen specimens to determine the required pulling direction of the stripped muscles and ligaments during surgery. In addition, the vascular and nerve traction protection directions exposed in the approach were observed and analyzed. The feasibility of this approach was assessed, and the operative approach and critical anatomical depth were measured. We retrospectively analyzed 12 patients with Pipkin type I and II femoral head fractures who underwent in situ reduction and fixation by anterior medial fenestration in our hospital from February 2016 to April 2018. The study group included 3 men and 9 women aged 37-59 years (mean, 48.50 years). There were 8 cases of Pipkin type I and 4 cases of Pipkin type II. The operation time, blood loss, fracture healing time, last Thompson-Epstein evaluation, and Harris score were recorded.

Results: A total of 8 fresh frozen specimens from 4 bilateral hips were exposed by anterior medial fenestration. The upper boundary of observation fenestration was the pubic body (anterior acetabulum), and the outer upper boundary was the iliacus and the psoas muscle. The lateral boundary was the rectus femoris and the femoral vessels, while the lower boundary was the transverse branch of the medial femoral circumflex artery and vein. The medial boundary was the pubis muscle, the short adductor muscle, and the long adductor muscle. The pubofemoral and iliofemoral ligaments were observed during fenestration. By cutting open the joint capsule and moving the hip joint, the four quadrants of the femoral head can be exposed. Twelve patients with femoral head fractures who were treated with anterior medial fenestration underwent in situ reduction and fixation. The operation time was 96.25-118.75 min (median, 100 min), and the blood loss was 115.00 ± 22.76 mL. The follow-up time was 18.58 ± 4.48 months, and the fracture healing time was 144.17 ± 14.53 days. The last Thompson-Epstein evaluation was excellent in 6 cases, good in 4 cases, and fair in 2 cases; the excellent and good rate was 83.33%. Finally, the last Harris score was 85.08 ± 5.73 points.

Conclusions: The upper and lower boundaries, inner and outer boundaries, and rear anatomical structure of the anterior medial fenestration approach were defined. The movable hip joint can expose the four quadrants in front of the femoral head in this fenestration. Anterior medial fenestration in situ reduction and fixation surgery is feasible and safe for the treatment of Pipkin type I and II femoral head fractures.

Keywords: Anterior medial; Approach; Femoral head; Fenestration; Fracture.