Reconstruction of non-contained acetabular defects with impaction grafting, a reinforcement mesh and a cemented polyethylene acetabular component.

This review summarises the technique of impaction grafting with mesh augmentation for the treatment of uncontained acetabular defects in revision hip arthroplasty. The ideal acetabular revision should restore bone stock, use a small socket in the near-anatomic position, and provide durable fixation. Impaction bone grafting, which has been in use for over 40 years, offers the ability to achieve these goals in uncontained defects. The precepts of modern, revision impaction grafting are that the segmental or cavitary defects must be supported with a mesh; the contained cavity is filled with vigorously impacted morselised fresh-frozen allograft; and finally, acrylic cement is used to stabilise the graft and provide rigid, long-lasting fixation of the revised acetabular component. Favourable results have been published with this technique. While having its limitations, it is a viable option to address large acetabular defects in revision arthroplasty. Cite this article: Bone Joint J 2017;99-B(1 Supple A):25-30.

Hypotensive epidural anaesthesia in patients with preoperative renal dysfunction undergoing total hip replacement.

BACKGROUND: Hypotensive anaesthesia does not impair renal function after surgery in normal patients but there are no reports of hypotensive anaesthesia in patients with chronic renal dysfunction (CRD). METHODS: From a database of 1893 consecutive patients undergoing total hip replacement (THR) under hypotensive epidural anaesthesia (HEA) from 1999 to 2004, 54 patients were identified with CRD (preoperative serum creatinine > or =124 micromol litre(-1)). Fifty matched pairs were identified for patients with normal renal function who have hypertension (n=50) or no hypertension (n=50). Changes in serum creatinine and blood urea nitrogen (BUN) were recorded daily for 3 days. Acute renal failure was defined as an increase in serum creatinine of 44 micromol litre(-1). RESULTS: The mean duration of hypotension (MAP<55 mm Hg) was 94 min (range 35-305 min). The mean age was 71 yr. All patients with a creatinine level of 124 micromol litre(-1) had a creatinine clearance of <40 ml min(-1) 1.73 m(-2) (range: 13-56). Patients with CRD received more crystalloid during surgery (1755 ml) than the other two groups (1435 ml) (P<0.001). Otherwise, all three groups were similar. No patients developed evidence of acute renal dysfunction immediately after or by 24 h after surgery. Three patients with CRD had an increase in creatinine of >44 micromol litre(-1) at 48 and 72 h after surgery in the setting of volume depletion (acute blood loss in two patients and early ileus in one). Renal function subsequently improved. CONCLUSION: HEA, per se, when carefully managed does not appear to predispose patients with CRD to acute renal failure after THR.

Insufficiency subchondral fracture of the femoral head: report of 4 cases and review of the literature.

Insufficiency subchondral fractures are nontraumatic flattened lesions in the superolateral area of the femoral head, occurring in healthy adults. These lesions were recently described and are an infrequent cause of acute hip pain. We report on 4 patients who were diagnosed with an insufficiency subchondral fracture. All the patients showed radiographic progression of the lesion after 4 months, and 3 patients required a total hip arthroplasty. The etiology and the natural history of these rare lesions remain to be elucidated. These lesions should be differentiated from osteonecrosis and transient osteoporosis, because treatment and prognosis may differ.