Anterolateral muscle sparing approach total hip arthroplasty： an anatomic and clinical study

Background Many kinds of approaches have been used for minimally invasive surgery of total hip arthroplasty （MIS-THA）. However, until now when considering the balance of efficacy and associated surgical injury there is no approach widely accepted for MIS-THA. In this study, a modified anterolateral muscle sparing approach was developed to optimize MIS-THA. Methods Twenty adult cadaver specimens （40 hips） were used for anatomic research. The distance from anterior origin of the gluteus medius on the iliac crest to the anterior superior iliac spine was measured; the course of the superior gluteal nerve and the distances from the nerve to the regional anatomic landmarks were recorded. Simulated surgeries were performed in three fresh cadaver specimens to evaluate the soft tissues injury around incisions. From October 2004 to June 2006, 57 patients （57 hips） were treated with anterolateral muscle sparing minimally invasive total hip arthroplasty, of which 17 were femoral neck fractures, 9 osteoarthritis, 16 developmental dysplasia of hip （DDH） and 15 avascular necrosis （AVN）. All the operations were performed by the same senior surgeon. Operation time, blood loss and drainage volume were recorded and the correlation between the local complications and the native anatomical characteristics was especially noted. All cases were followed for at least 12 months. Results The distance from the anterior origin of the gluteus medius to anterior superior iliac spine along the iliac crest was （61±4） mm （range, 55-68 mm）, and the distance from inferior branch of the superior gluteal nerve to the anterior tubercle of the greater trochanter was （74±6）mm （range, 60-88 mm）. In simulated surgeries, excessive distraction of tissue was found to be the main cause of the anterior border injury of the gluteus medius muscle. Of the 57 patients treated with anterolateral muscle sparing MIS-THA, the average incision length was 9 cm （range 7.5-13 cm）. Blood transfusions were performed in 11 patients. During the operations, anterior border injury in deep layers of the gluteus medius was found in 9 patients. Posteromedial perforation of the prosthesis stem on the femoral side was found in 2 patients, which were revised immediately. No positive Trenderlenburg sign was found during the 12 months of follow-up. Conclusions The incision of the anterolateral muscle sparing approach should be directed from the anterior tubercle of the greater trochanter toward 6 cm posterior to the anterior superior iliac spine. The proximal part of the incision should be within 6 cm from the anterior tubercle of the greater trochanter, and it is safe to be extended distally. The anterolateral muscle sparing approach is a minimally invasive approach for total hip arthroplasty, through which the surgeon can operate on the acetabulum and femoral sides in a single incision without muscle detachment, and fluoroscopy assistance is not needed. The surgeon should pay more attention to protecting the gluteus medius from injury by distraction before femoral neck cutting and during the preparation of the femoral side.

Horizontal platform supported total hip replacement

Objective To investigate the effect of horizontal platform supported (HPS) prosthesis on cementless total hip replacement for surgical treatment of arthritis in a long-term follow-up study.Methods Clinical and radiographic follow-up of 65 consecutive primary cementless porous coated HPS total hip replacements, which were implanted in 60 patients between 1982 and 1989, was carried out.Results The 53 hips in 50 patients were evaluated both clinically and radiographically. The average follow-up was 6.8 years (range: 5 to 12 years). According to the Harris hip score, 52 (98%) of the hips had sustained an excellent or good result with an average score of 92. At the time of final assessment, no patient experienced anterior thigh pain. There were two revisions performed early in the series due to technical failures. Radiographically, osteolysis and bone re-modelling were assessed. Conclusion The findings suggest that the clinical and radiographic results after cementless total hip replacement for primary hip arthroplasty may be favourably influenced by the use of the proximal stress loaded HPS femoral component.

Combined use of extensively porous coated femoral components with onlay cortical strut allografts in revision of Vancouver B2 and B3 periprosthetic femoral fractures

Background Periprosthetic femoral fractures following total hip arthroplasty are getting more prevalent. The aim of this study was to evaluate the clinical results of combined use of uncemented extensively porous coated femoral components with onlay cortical strut allografts in revision of Vancouver type B2 and B3 periprosthetic femoral fractures. Methods Thirteen hips after total hip arthroplasty in 13 patients who suffered a Vancouver B2 or B3 periprosthetic fracture were treated with an uncemented extensively porous coated femoral component combined with onlay cortical strut allografts. Each patient was assigned a Harris hip score, and a visual analog scale （VAS） score for pain and satisfaction. Radiographs were examined for component stability, fracture site and allograft-host union and allograft reconstruction. Results At an average of 5.3-year follow-up, no patient required repeat revision. The average Harris hip score was （71.8±6.3） points, the pain VAS score was （16.6±4.3） points, and the patient satisfaction VAS score was （81.5±5.7） points Radiographic examination showed no detectable loosening of the prostheses, and 12 cases were presented fixation by osseointegration and the other one was stable fibrous ingrown fixation. All fractures united for （5.2±1.4） months in average. And all onlay strut allografts united to host bone for about （11.5±2.6） months. Conclusions Combined use of uncemented, long stemmed, extensively porous coated implant with cortical onlay strut allografts can achieve good clinic results and high rate of union for both fracture site and allograft-host bone junction. This technique could be used routinely to augment fixation and healing of Vancouver B2 and B3 periprosthetic fractures.