DANA MEARS TRIRADIATE APPROACH FOR ACETABULAR SURGERY: ADVANTAGES AND DISADVANTAGES

Abstract

Purpose: Among 80 surgical treatments for acetabular fracture, the Dana Mears approach was used in 15. The purpose of this study was to analyse functional and radiological outcome of these fractures at a mean follow-up of 41 months.

Material and methods: The AO classification was used for fractures of the acetabulum : 12 class B (80%) with five B1a2 five B2a1 and two B1a1, and three class C (20%). There was one deformed callus (B1a2) at 120 days Two patients had associated pelvic injuries, eight a hip dislocation, and two an initial sciatic palsy. There were also two osteochondral fractures of the femoral head. The Dana Mears approach was modified slightly in the anterior part passing in front of the tensor muscle to preserve innervation. The gluteal muscles were raised by trochanterotomy. The displacement, the head/ roof congruency and the head/acetabulum congruency were assessed according to the 1981 SOFCOT criteria on the initial x-rays (AP pelvis, oblique ala and obturator) and computed tomographies. The quality of the reduction was assessed with the Matta and Duquesnoy-Senegas criteria. Clinical results were assessed with the Postel Merle d’Aubigné (PMA) score.

Results: Radiographically, there was an anatomic reduction in 73.3% of the cases and perfect head/roof congruency in 80%. Functional outcome was excellent or good in 80% of the patients. Postoperative complications included 11 ossifications, and one transient sciatic paralysis. There was one late aseptic osteonecrosis of the femoral head.

Discussion: The functional prognosis of these fractures is significantly correlated with the quality of reduction (p < 0.05). The advantage of this approach is the direct access to the roof without disinsertion of the gluteal muscles from the iliac crest, allowing more rapid recovery (seven to eight months) of medius gluteus function. In principal drawback is the very high rate of ossifications (one patient required revision for arthrolysis).

Conclusion: The Dana Mears triradiate approach is an integral part of the surgical treatment of acetabular fractures, particularly for B1a2 and B2a1 fractures, but also for B1a1 transtectal fractures. Conversely, this approach is insufficient for reduction of type C fractures requiring and extensive access to the iliac wing and for surgery of deformed calluses where an endopelvic approach is indispensable to control the vessels.