A retrospective review was conducted of patients undergoing either total hip replacement or hemiarthroplasty for intra-capsular neck of femur fractures between April 2013 and April 2014; identified from entries into the National Hip Fracture Database. PACS and the electronic database encompassing operation notes and discharge summaries were reviewed. 309 patients were identified, 3 of whom fractured both hips during the study period giving a total of 312 operations. The age range was 46 to 102 with a mean age of 82. 59 cemented bipolar hemiarthroplasties, 143 cemented unipolar hemiarthroplasties, 2 uncemented hemiarthroplasties and 108 total hip replacements were performed. 10 patients required further operations. There have been 5 dislocations: 2 underwent MUA only, 2 treated by excision arthroplasty and 1 converted to THR. 1 patient developed a haematoma requiring wound washout. There were 4 wound infections - 1 treated by a washout, 2 by excision arthroplasty and one patient has undergone first stage revision; an overall reoperation rate of 3.2% comparing well with data published elsewhere.

Stress fractures occurring in the pubis and ischium after peri-acetabular osteotomy (PAO) are not well recognised, with a reported incidence of 2% to 3%. The purpose of this study was to analyse the incidence of stress fracture after Bernese PAO under the care of two high-volume surgeons. The study included 359 patients (48 men, 311 women) operated on at a mean age of 31.1 years (15 to 56), with a mean follow-up of 26 months (6 to 64). Complete follow-up radiographs were available for 348 patients, 64 of whom (18.4%) developed a stress fracture of the inferior pubic ramus, which was noted at a mean of 9.1 weeks (5 to 55) after surgery. Most (58; 91%) healed. In 40 of the patients with a stress fracture (62.5%), pubic nonunion also occurred. Those with a stress fracture were significantly older (mean 33.9 years (16 to 50) vs 30.5 years (15 to 56), p = 0.002) and had significantly more mean pre-operative deformity: mean centre–edge angle (9.8° (-9.5 to 35) vs 12.4° (-33 to 28), p = 0.04) and mean Tönnis angle (22.8° (0 to 45) vs 18.7° (-2 to 38), p < 0.001). The pubic nonunion rate was significantly higher in those with a stress fracture (62.5% vs 7%, p < 0.001), with regression analysis revealing that these patients had 11.8 times higher risk than those without nonunion.

Cite this article: Bone Joint J 2015; 97-B:24–8.

Although there is still no absolute diagnostic test for infection of the prosthetic joint, the synovial fluid leukocyte count and neutrophil percentage have been reported as having high sensitivity and specificity but to date the cut off values for these tests are not agreed upon. We investigated whether leukocyte count and differential of aspirated joint fluid are valuable tools in the diagnosis of suspected prosthetic joint infection.

In 39 patients who underwent revision arthroplasty the cell count and differential of joint aspirates were cross-referenced with culture results and histology to confirm that these were valid tests and to determine cut off values. Cases were identified via the microbiology service of two district general hospitals: 17 patients in whom infection was identified via culture and/or histology results and 19 who were uninfected.

Receiver operator characteristic curves were used to determine the correlation between the results of the two tests and to identify a suitable threshold level. For absolute leukocyte count the area under the curve was 0.997 indicating excellent agreement between the tests. A cut off value of 2000 gave a sensitivity of 100% and a specificity of 94%. Differential count had an area under the curve of 0.94. A threshold of 50% had a sensitivity of 100% and a specificity of 77%.

Despite the low number of patients this study shows that the leukocyte count and differential of aspirated joint fluid are valuable tools in the diagnosis of suspected prosthetic joint infection.

Hip resurfacing arthroplasty is an established and effective intervention for osteoarthritis of the hip in the young active patient, relying on the principle of femoral bone-stock preservation. A recognised mode of failure is neck thinning leading to radiological evidence of neck collapse and clinical failure.

We report on a series of these slow-neck-failure patients and highlight the increased incidence of this phenomenon in post-menopausal female patients. This is a single operator, single implant series; 172 cases were identified from databases at our institution. 76 were female, mean (SD) age 52 (7) years. 96 were male, mean (SD) age 51(12) years. 15 (8.7%) patients required revision. 12 (80%) were female, 9 (75%) of these were due to slow neck failure. In the men one patient developed ALVAL requiring removal of his bilateral hip resurfacings, the other failure mode was early femoral neck failure. Mean time to failure was 6 months in men and 37 months in women. This difference in failure rates is also seen in the NJR figures.

This review confirms the relatively high incidence of premature failure in post-menopausal females. NICE guidance in 2003, currently under review, stated that resurfacing is indicated in male patients up to 65 and female patients up to 60. As a result of this study we are currently advising post-menopausal patients that this risk of early failure may make total hip replacement a preferable option to resurfacing arthroplasty.