There is a significant increase in the incidence of acetabular fractures in the elderly population[1]. The management of these fractures is both complex and costly. An excellent functional outcome and long-term survival can be achieved with open reduction and internal fixation (ORIF) of displaced acetabular fractures[2,3]. However, the surgery is often technically challenging in the elderly osteopenic or osteoporotic patient, with a higher risk of fixation failure and post-traumatic osteoarthritis. 12 to 25% of operatively or non-operatively managed fractures of this type require conversion to total hip replacement (THR). If there is non-anatomical reduction, posterior wall involvement, hip dislocation, residual displacement, femoral head or acetabular impaction, incarcerated fragments, fracture comminution, chondral damage of the femoral head, marginal impaction, non-union or fixation failure, the outcomes are poorer, and the risks of conversion to a THR are increased, predominantly due to the development of post-traumatic arthritis[4,5].

Futhermore, in the context of acetabular ORIF failure, the function and patient reported outcome measures (PROMs) following the final THR is worse than that of a primary THR in the acetabular fracture setting[6].

In the elderly, osteoporotic population, significant treatment challenges exist. This is due to the difficulty to achieve and maintain an anatomic reduction in poor quality bone, particularly where articular impaction exists[7]. The almost inevitable post-traumatic arthritis[8] renders the joint painful and stiff, propagating the cycle of further falls, fractures, and increased morbidity, with a decline in the patient's physiological reserves including muscle mass and proprioceptive qualities.

One management option is initial non-operative treatment, with delayed arthroplasty. These operations have high complication rates and are technically difficult due to fracture malunion, femoral head medialisation, loss of abductor function and periarticular fibrosis[6,9,10]. Not only is there poorer postoperative function when compared to conventional total hip arthroplasty[11], but there is evidence that the morbidity and mortality associated with these injuries is similar to the elderly neck of femur fracture population[12,13].

Open reduction with internal fixation alone is an option for these patients, with lower implant costs and quicker surgery. However, it is rare to be sufficiently confident in the fixation construct in poor quality bone to allow immediate full weight bearing[14]. It is recognised that elderly patients are often unable to non-weight bear on an injured lower limb, and this often limits their mobility to chair transfers only while waiting for the fracture to unite[15].

Consequently, treatment of certain acetabular fractures in this population with immediate total hip replacement has gained popularity, the prime advantage being that it allows immediate weight bearing, earlier rehabilitation, and a resultant reduction in the morbidity associated with prolonged immobility.

A variety of constructs and approaches have been described to reconstruct the acetabulum[16], [17], [18], [19], [20], [21], [22] with the ‘fix and replace’ concept (a term coined by the senior author). The rationale behind the concept is to restore sufficient pelvic and acetabular bone stability using ORIF, in order to allow the insertion of an acetabular cup and resultant immediate full weight-bearing by the patient.

We present a consecutive series of 57 patients treated with simultaneous acute acetabular fracture fixation and THR (‘fix and replace’), and describe our technique, present immediate post-operative and 12 month clinical and radiographic outcomes.