We present the results of Chiari pelvic osteotomy in the treatment of adolescent hip incongruence, with special interest in identifying possibilities, limitations and complications. In a series of 86 patients treated by Chiari pelvic osteotomy (13 operated bilateraly) at the Institute for Orthopaedic Surgery “Banjica” with a follow-up period more than 48 months, we analyzed the relation of Chiari-specific parameters collected from postoperative radiograms (osteotomy angle and heigth, and displacement index) to various preoperative and postoperative parameters (Sharp acetabular angle, Wiberg CE angle, Heyman and Herndon femoral head extrusion index (FHEI), Acetabular depth ratio (ADR), Shenton-Menard arch integrity, limb length discrepancy, gait quality) and functional result according to HHS and McKay scoring systems. We found highly significant improvements of Sharp angle (from 47.2±6.1° preoperatively to 38.6±7.8° finally, p<0.01), Wiberg CE angle (from 10.2±16.8° to 38.9±14.6°, p<0.01) and FHEI (from from 53.4±21% to 1.9±70.7%, p<0.01). In adition, HHS was also improved from 76±15.1 to final 87.9±9.4, p<0.01). We also assessed the satisfaction of both patients (index 4.2 out of 5) and surgeons (index 3.7 out of 5). Chiari pelvic osteotomy is useful surgical procedure in the selected cases of adolescent hip incongruence with disturbance of hip centering and coverage

Purpose. Exeter stem was introduced to Japanese market at 1996. Since then, owing to its excellent clinical results, the number of the stem used has been increased year by year and more than 2000 stems have been implanted during the year 2009. The present study aims to prove its efficacy for Japanese patients by evaluating short term results of four major dedicated hip centers. Method. We present the short-term multi-center results of primary THA with Exeter stem combined with modern cementing technique in 881 patients (1000 hips). The average age of the patients at operation was 62.3years (ranging 23 to 89 years). Mean postoperative follow up period was 4.0 (ranging 2 to 9) years. Results. Intraoperative complications such as femoral fracture were observed in 6 hips. Postoperative cementing grade using Barrack's classification was judged as A for 735 hips, as B for 246 hips, and as C for 4 hips, respectively. Twenty-four patients died with unrelated disease and 52 patients were lost during follow-up period. Follow-up ratio was 94.8%. Thirty postoperative complications which include 9 infections, 14 dislocations, 5 deep vein thrombosis, and 2 sciatic nerve palsies were observed. Symptomatic pulmonary embolization or femoral fracture was not observed. Re-operations for infection and dislocation were performed for 8 and 6 hips, respectively. At the final follow-up, no radiolucent line at bone-cement interface was observed. Cortical hypertrophy was observed in 9.6% at Gruen zone 2 to 6. Kaplan-Meier survivorship analysis predicted a rate of survival at 5 years of 100% with radiolucent line at bone-cement interface of the femur as the endpoint, and of 98.8% when re-operation for any reason was used. Conclusion. The present study revealed excellent short-term result was obtained using Exeter stem combined with modern cementing technique for primary THAs in Japan

Introduction. It was the purpose to evaluate the biomechanical changes that occur after optimal and non-optimal component placement of a hip resurfacing (SRA) by using a subject specific musculoskeletal model based on CT-scan data. Materials and Methods. Nineteen hips from 11 cadavers were resurfaced with a BHR using a femoral navigation system. CT images were acquired before and after surgery. Grey-value segmentation in Mimics produced contours representing the bone geometry and identifying the outlines of the 3 parts of the gluteus medius. The anatomical changes induced by the procedure were characterised by the translation of the hip joint center (HJCR) with respect to the pelvic and femoral bone. The contact forces during normal gait with ‘optimal’ component placement were calculated for a cement mantle of 3 mm, a socket inclination of 45° and anteversion of 15°. The biomechanical effect of ‘non-optimal placement’ was simulated by varying the positioning of the components. Results. There was a significant (p<0.01) shortening of the muscle length with the ‘optimal’ component placement for all parts of the gluteus medius with the largest shortening of the posterior part by 6mm. This was caused by a significant shortening of the femoral offset by 2.3mm (p<0.01). Because of a significant (p<0.01) medialisation of the HJCR by 4 mm, there was no significant increase in contact force. The hip joint contact forces increased by 0.5% per mm HJCR displacement. Each millimeter of cranial and lateral displacement of the femoral HJCR increased the contact force by 0.5% and 1%, respectively. The contact stresses changed significantly by 0.8% and 0.2% per degree of socket inclination and anteversion. The contact force increased 1% per mm lateral displacement of the acetabular HJCR. Discussion. Optimal placement of the SRA components did not completely restore the biomechanics of the native hip joint. The contact forces were not increased due to the compensatory effect of the medialisation of the acetabular HJCR. This suggests that reaming to the acetabular floor should be conducted in SRA. Femoral component displacement in the cranial and lateral direction significantly increased the hip joint loading. Errors of socket placement in the coronal and sagital plane significantly increased the contact stresses. Accumulative errors of both component displacements could lead to increased contact stresses of 18% to 23% with socket inclinations of 50° and 55°. Surgeons should reconsider continuing the SRA procedure if a neck length loss and lateralisation of the HCJR by >5 mm is anticipated as this would increase the contact stresses by >12%

Aims

Bone health assessment and the prescription of medication for secondary fracture prevention have become an integral part of the acute management of patients with hip fracture. However, there is little evidence regarding compliance with prescription guidelines and subsequent adherence to medication in this patient group.