Surgical treatment of acetabulum posterior wall fractures: Comparison between undercountering and marginal impaction reconstruction method with odd methods

Abstract

Background

Modern treatment principles for posterior wall fractures have become widespread in the last decade in many countries by means of international or local courses. The purpose of this study was to compare the clinical and radiologic outcomes of acetabulum posterior wall fractures using unconventional methods of fixation, including plates placed in unusual directions, or, in the case of reoperation, only interfragmentary screws. In addition, we examined acetabulum posterior wall fractures treated by open reduction and internal fixation with standard undercountered plates from ischion to iliac bone in latter cases.

Methods

Twenty-one patients who had open reduction and internal fixation of an unstable unilateral fracture of the posterior wall of the acetabulum between 2009 and 2013 were included. Group 1 was composed of 10 former patients who were treated with unconventional methods that included a compression technique with a direct plate or solely screw fixation. Group 2 was composed of latter 11 patients who were treated with standard surgery that included undercountered plates oriented from the ischial tuberosity to the iliac bone proximally and reconstruction of marginal impaction if necessary. The functional outcome was evaluated with the use of the clinical grading system adopted by Merle d'Aubigné and Postel. The Kellgren–Lawrence radiologic criteria were used for the radiologic assessments. The reduction of the fracture, posterior dislocation, marginal impaction, mean fracture particle amount, trochanteric osteotomy and avascular necrosis were compared between the two groups and examined with the Mann–Whitney U test.

Results

In Groups 1 and 2, the median score of the modified Merle d'Aubigné and Postel clinical scoring system was 16 (8–18) and 18 (14–18), respectively. The clinical scores between the two groups were statistically significant (p < 0.01). When two groups were compared using the Kellgren–Lawrence radiographic criteria for the development of osteoarthritis, the median value in Groups 1 and 2 was 3 (0–4) and 1 (0–3), respectively (p < 0.01).

Conclusions

This study displays the evolution of the surgical treatment of acetabular fractures of the posterior wall in our clinic. The older methods failed in terms of exposure, diagnosis of fracture anatomy and fixation techniques. Patients treated after the surgeons took courses in this field showed evidence of superior clinical and radiological scores. We attribute these benefits to exposure, definition and treatment of marginal impaction and fixation principles.

Introduction

Although the operative treatment of acetabular fractures has become widespread in the last three decades, only a few centres have the technical expertise to effectuate a prompt treatment of these fractures.^1,2 Currently, open reduction and rigid fixation is typically the first choice in the treatment of acetabular fractures.^2,3 In Turkey especially in the last 5 years, the standard surgical techniques have become more common since the introduction of the AO trauma and the Turkish Society of Orthopaedics and Traumatology (TOTBİD) pelvis and acetabular fractures courses.

Posterior wall fracture is among the most commonly seen types of acetabular fractures. This type of fracture is also the most frequently underestimated and may often be met with suboptimal care because of the simple appearance of the fracture pattern even without awareness of marginal impaction or other features. However, current studies show that progressive posttraumatic osteoarthritis can develop after displacements of more than 1 mm; also, functional and radiologic scores decrease after non-anatomical reduction.^4,5 Anatomical reduction and marginal impaction reconstruction of the weight-bearing surfaces of the acetabulum (acetabular roof), consistence of femoral head and condition of the acetabulum are important factors in retaining normal hip functions.⁶

Considering the simplicity of the fracture pattern in posterior wall fractures, we wanted to determine if it is necessary to rigidly comply with the AO trauma and Letournal fixation principles or if unconventional surgical methods would also work. The objective of our study was to compare the treatment of acetabular posterior wall fractures with unconventional methods in former patients and standard methods in latter patients, by means of clinical, functional and radiological criteria.