Heterotopic ossification (HO) of the hip after injury to the central nervous system can lead to joint ankylosis. Surgery is usually delayed to avoid recurrence, even if the functional status is affected. We report a consecutive series of patients with HO of the hip after injury to the central nervous system who required surgery in a single, specialised tertiary referral unit. As was usual practice, they all underwent CT to determine the location of the HO and to evaluate the density of the femoral head and articular surface. The outcome of surgery was correlated with the pre-, peri- and post-operative findings. In all, 183 hips (143 patients) were included of which 70 were ankylosed. A total of 25 peri-operative fractures of the femoral neck occurred, all of which arose in patients with ankylosed hips and were associated with intra-articular lesions in 18 and severe osteopenia of the femoral head in seven. All the intra-articular lesions were predicted by CT and strongly associated with post-operative complications. The loss of the range of movement before ankylosis is a more important factor than the maturity of the HO in deciding the timing of surgery. Early surgical intervention minimises the development of intra-articular pathology, osteoporosis and the resultant complications without increasing the risk of recurrence of HO.

Even though a learning curve is necessary to achieve this extreme type of surgery, selective preoperative screening of patients is mandatory. Interesting results today confirm the feasibility of possible treatment of tumors still considered unresectable.

We aimed to report causes of readmission 30 and 90 days following a total hip arthroplasty (THA) using the direct anterior approach (DAA). Methods: Three hundred and two patients (335 hips) underwent a DAA-THA for primary osteoarthritis. Results: The main reasons for 30 and 90-day readmission were wound related problems, dislocation (rate: 0.9%) and deep infection. The readmission rates at 30 and 90 days were 1.8% and 2.7%, respectively. Age over 60 years and morbidly obese patients were at risk for complications. Conclusion: The DAA-THA was associated with low readmission rates. Obesity should be adressed preoperatively.