Although the principles of their management are the same as any other major bony injury, acetabular fractures are special injuries that remain the province of the specialist. This is because they are relatively rare limiting high volume personal experience and are commonly operated through major approaches not familiar to most surgeons. While the results of surgery depend on accurate reduction and stable fixation and thus on access, the commonly used approaches only allow access to one side of the acetabulum and rely on indirect reduction of the opposite column. There is very limited visualisation of the inside of the acetabulum unless a specific traction table is used and often none at all.
Surgical hip dislocation was popularised by Ganz and allows safe dislocation of the femoral head with full visualisation of the inside of the acetabulum and the femoral head. With acetabular fractures it creates the potential to evaluate and potentially treat cartilage or labral lesions and problems with the femoral head. It also allows the surgeon to monitor fracture reduction under direct vision, and check for misplaced hardware entering the joint. This report describes the use of this approach in 60 patients with acetabular fractures. Not surprisingly the authors identified substantial intra-articular cartilage damage in the areas of the femoral head and acetabulum at risk and a number of (mainly posterior) labral injuries they were even able to observe and treat potential femoral head impingement problems in a number of cases. The added visibility leads to an improvement in the rate of an anatomical reduction and thus to and improvement in the outcome when compared with previous reports. Importantly as the hip was surgically dislocated they reported no cases of avascular necrosis. This last issue is unexpected as a number of cases of AVN should have been seen in this group of patients as several of them had been dislocated at presentation. The authors even suggest that this approach, used to specifically protect the femoral head may even have a protective effect against AVN, an interesting possibility that requires further consideration. There are some disadvantages with this approach, it requires specific experience and is performed in the lateral position. This leads to major problems reducing fractures with a transverse element. In this position it is much more difficult as the weight of the leg and hip forces the reduction apart. I would still recommend operating on these fractures in a prone position where gravity is eliminated and the reduction facilitated. Overall this approach is probably most applicable to posterior wall injuries where there is often comminution, marginal impaction or intra-articular loose bodies that increase the surgical difficulty and worsen the results of reconstruction.
This report really illustrates the progress of thinking with acetabular surgeons constantly looking at ways to improve the results in reconstructive acetabular surgery. It represents the largest current series of patients operated on in this way and importantly illustrates the significant nature of the cartilage injury in these patients. The results are very good and better than historical controls. However, while useful the approach is still one familiar to few surgeons and only applicable to certain fracture patterns. Acetabular fractures, even posterior wall injuries, will and should remain the province of the specialist.
Smith RM, MD, FRCS
Department of Orthopedic Surgery, Massachusetts General Hospital, Boston, USA