Background and purpose — Intraoperative periprosthetic femoral fracture is a known complication of cementless total hip arthroplasty (THA). We determined the incidence of—and risk factors for—intraoperative calcar fracture, and assessed its influence on the risk of revision.Patients and methods — This retrospective analysis included 3,207 cementless THAs (in 2,913 patients). 118 intraoperative calcar fractures were observed in these hips (3.7%). A control group of 118 patients/hips without calcar fractures was randomly selected. The mean follow-up was 4.2 (1.8–8.0) years. Demographic data, surgical data, type of implant, and proximal femur morphology were evaluated to determine risk factors for intraoperative calcar fracture.Results — The revision rates in the calcar fracture group and the control group were 10% (95% CI: 5.9–17) and 3.4% (CI: 1.3–8.4), respectively. The revision rate directly related to intraoperative calcar fracture was 7.6%. The Hardinge approach and lower age were risk factors for calcar fracture. In the fracture group, 55 of 118 patients (47%) had at least one risk factor, while only 23 of118 patients in the control group (20%) had a risk factor (p = 0.001). Radiological analysis showed that in the calcar fracture group, there were more deviated femoral anatomies and proximal femur bone cortices were thinner.Interpretation — Intraoperative calcar fracture increased the risk of revision. The Hardinge approach and lower age were risk factors for intraoperative calcar fracture. To avoid intraoperative fractures, special attention should be paid when cementless stems are used with deviant-shaped proximal femurs and with thin cortices.

Background and purpose Previous population-based registry studies have shown that larger femoral head size is associated with reduced risk of revision for dislocation. However, the previous data have not included large numbers of hip resurfacing arthroplasties or large metal-on-metal (> 36-mm) femoral head arthroplasties. We evaluated the association between femoral component head size and the risk of revision for dislocation after THA by using Finnish Arthroplasty Register data.Patients and methods 42,379 patients who were operated during 1996–2010 fulfilled our criteria. 18 different cup/stem combinations were included. The head-size groups studied (numbers of cases) were 28 mm (23,800), 32 mm (4,815), 36 mm (3,320), and > 36 mm (10,444). Other risk factors studied were sex, age group (18–49 years, 50–59 years, 60–69 years, 70–79 years, and > 80 years), and time period of operation (1996–2000, 2001–2005, 2006–2010).Results The adjusted risk ratio in the Cox model for a revision operation due to dislocation was 0.40 (95% CI: 0.26–0.62) for 32-mm head size, 0.41 (0.24–0.70) for 36-mm head size, and 0.09 (0.05–0.17) for > 36-mm head size compared to implants with a head size of 28 mm.Interpretation Larger femoral heads clearly reduce the risk of dislocation. The difference in using heads of > 36 mm as opposed to 28-mm heads for the overall revision rate at 10 years follow-up is about 2%. Thus, although attractive from a mechanical point of view, based on recent less favorable clinical outcome data on these large heads, consisting mainly of metal-on-metal prostheses, one should be cautious using these implants.

Background and Aims: total hip arthroplasty significantly improves patient's life quality. however, total joint replacement is associated with possible complications, such as dislocations, infections, fractures and periprosthetic osteolysis. the goal of this study was to evaluate a large head metal-on-metal total hip arthroplasties and analyse short term complications related to them.Material and Methods: between 9/2005 and 6/2009, a total of 691 hip replacements were performed on 635 patients with the use of magnum m2 large head cementless metal-onmetal prosthesis in turku university hospital. all patients had a scheduled follow-up at two to three months, and at one year. the results were evaluated using X-rays, harris hip score (hhs), and evaluating post-operative complications and reasons for re-operations.Results: during our follow-up the hhs median raised from its preoperative value of 59.8 to 86.4 two to three months after the operation, and to 93.9 one year after the operation. as a complication we had five infections requiring single open debridement (early infection) or a two stage revision. seven patients had a periprosthetic femoral fracture that was operated and 11 patients were reoperated because of acetabular component malposition, fracture or early loosening. We did not observe any dislocations, n. ischiadicus damages, squeeking or complications related to high metal ion release (alVal-reactions (aseptic lymphocyte-dominated Vasculitis-associated lesion) or pseudotumours).Conclusions: the metal-on-metal bearing pair allows large femoral head size, which decreases the risk for dislocation. it may also decrease the risk for osteolysis and aseptic loosening in a long run. Early complication rate related to the bearing surface is minimal. metal-on-metal prosthesis is a good choice for young and active patients with good bone quality.

Background and Aims: large headed metal-on-metal total hip arthroplasty may produce more metal ions than hip resurfacing arthroplasty. increased metal-ion levels may be associated with higher revision rates due to adverse reaction to metal debris. the purpose of our study was to compare the survivorship of three hip resurfacing arthroplasty designs with their analogous cementless large-diameter head metal-on-metal total hip arthroplasties.Material and Methods: based on data obtained from the finnish arthroplasty register, the revision risks of three metal-on-metal hip resurfacing arthroplasty/total hip arthroplasty design couples performed during 2001-2011 were analyzed using the cox regression model.Results: in the cox regression analysis for compared design pairs adjusted for age, gender, operated side, head size, diagnosis, and implant, there was no statistically significant difference in revision risk between recap hip resurfacing arthroplasty and bimetric/recap total hip arthroplasty (risk ratio = 1.43, confidence interval = 0.95-2.14, p = 0.09) or between birmingham hip resurfacing arthroplasty and synergy/birmingham hip resurfacing total hip arthroplasty (risk ratio = 1.35, confidence interval = 0.75-2.43, p = 0.31). However, the revision risk of corail and summit/articular surface replacement total hip arthroplasty (asr Hra) was significantly increased compared to asr Hra. (risk ratio = 0.73, confidence interval = 0.54-0.98, p = 0.04).

Our results were inferior compared to some previous studies. Impaction bone grafting of acetabular defects in revision total hip arthroplasty may not always provide a reliable bone stock in long-term.