Total Hip Arthroplasty in the Setting of Post-Traumatic Arthritis Following Acetabular Fracture: A Systematic Review

Acetabular fractures are uncommon fractures historically associated with high-energy trauma in the young patient [], however are increasingly seen following low-energy trauma in the elderly [,]. Associated injuries to acetabular and femoral cartilage as well as the femoral blood supply are common [] and frequently lead to painful and debilitating post-traumatic arthritis (PTA) [,]. Furthermore, a high proportion of patient progress clinically toward requirement of total hip arthroplasty (THA) [, , ], with a number of demographic factors including age and female gender [,], alongside technical factors such as residual fracture displacement and gap [,], associated with progression to THA.

THA has been shown to yield excellent clinical results for patients regarding return to activities of daily living and reported pain relief []. However, surgeons and patients must be cognizant that anatomic distortion following initial injury alongside changes in bone stock may precipitate potential complication of the task of performing THA postacetabular fracture, leading to higher complication rates when contrasted to those reported for primary THA []. This is further compounded for those patients in whom THA follows initial open reduction internal fixation (ORIF), with additional challenges posed such as possible occult infection [], in-situ metal work, and high rates of heterotopic ossification []. In their previous systematic review, Stibolt et al. [] reported the results of 448 patients following THA in the setting of acetabular trauma, with varying rates of surgical revisions reported up to 32% despite significant improvements in functional outcomes in the medium term. However, in recent years, the literature on this topic has grown exponentially, and therefore, the authors of this study believe an updated review is warranted.

This study aids orthopaedic surgeons when planning and consenting patients for THA in the setting of PTA postacetabular fracture. This is achieved by providing a comprehensive review of the current literature which may serve as a reference, both pertaining to clinical outcomes in terms of patient-reported outcomes, implant survivorship and complications, as well as describing implants and techniques utilized. A secondary aim is to highlight the implications of previous acetabular fracture ORIF in subsequent THA procedures.

The most important finding in this study was the improvement in patient-reported clinical outcomes in all studies reporting such in patients who underwent THA in the setting of PTA following acetabular fractures. This study found that clinical improvement was reported throughout short-term and into medium-term follow-up in studies reporting outcomes of patients following THA for PTA following acetabular fractures. In their study of 78 THAs, Garcia Rey et al [] reported an increase in the HHS from the 6-month and 2-year follow-up, in both ORIF (83.0 to 89.6) and conservative (84.6 to 91.0) cohorts. These scores were maintained for both ORIF and conservative groups at the long-term follow-up (89.5 and 91.3, respectively). Therefore, satisfactory early patient-reported outcomes appear to correlate positively with potentially promising clinical outcomes in the medium- and long-term post-THA for PTA in patients with previous acetabular fractures.

Surgery setting was cited by Clarke-Jensson et al [] as a possible factor in surgical outcomes. Their study of 52 THAs across 6 Norwegian hospitals, included 40 THA performed in a specialist pelvic institution. A higher postoperative HHS score was noted for those THA performed in the pelvic center, 88 ± 13, compared to those performed in a non-specialist institution, 75 ± 6. This follows findings from general THA studies which have found an association between THA outcomes and complications with both surgeon and hospital volume [, , ].

As highlighted by Aali Reziae et al [] who observed markedly raised infection rates in their acetabular fracture THA cohort (6.9% 5 of 72) vs control (0.5% 1 of 204), infection is a major concern when performing THA for patients with a history of prior acetabular fracture. Evidence or suspicion of existing infection was commented on in several studies and posed challenges both in identification and management [,,,,,]. Ranawat et al [] identified 8 patients with a history of infection composed of 5 from their ORIF cohort and 3 from their conservative cohort. Despite a rigorous preoperative protocol including laboratory investigations, hip aspiration and 5 intraoperative cultures all returning negative, 75% of this group (6/8-4/5 ORIF, 2/3 conservative) went on to experience an infection following THA, while the 24 other patients in the study were unaffected by infection. Similarly, Yuan et al [] in a study of 30 THA, identified 5 patients with a history of infection following ORIF, for whom THA was performed in a staged format after an antibiotic holiday of 2 weeks with normal inflammatory markers following initial removal of metal with a mean interval of 12 months. Despite these 3 of the 5 hips progressed to prosthetic joint infection necessitating resection arthroplasty, with no infection reported in their other patients. It is thus advisable that surgeons counsel patients with PTA following acetabular fractures appropriately regarding the potential risk of infection and its implications. Clinical and biochemical screening for infection should be incorporated in to the routine preoperative workup of this at-risk patient cohort. Two-stage procedure with use of an antibiotic impregnated cement was used successfully on the basis of intraoperative findings or history of infection for 9 THAs in 3 studies, with no infection reported in these cases at follow-up, and thus should be considered as a means to mitigate this devastating complication [,,].