Hip resurfacing and osteonecrosis: results from an independent hip resurfacing register

Introduction

Single surgeon studies from specialized centers have suggested that metal-on-metal hip resurfacing in patients with osteonecrosis of hip joint provides good implant survival and function.

Method

We tested the hypothesis that multicenter results of hip resurfacing, in terms of function and survival, are similar between patients with osteoarthritis and osteonecrosis.

Patients

192 patients (202 hips) underwent metal-on-metal hip resurfacing at different centers around the world. We compared the revision risks in 95 patients (101 hips) with osteonecrosis and 97 patients (101 hips) with osteoarthritis.

Results

The mean age at operation was 42 and 43 years and the preoperative and postoperative Harris hip scores were 62 and 96 and 58 and 95 for osteonecrosis and osteoarthritis groups. Survival with revision for any reason as the end point at last follow-up was 97.7% for osteonecrosis and 95.0% for osteoarthritis.

Conclusion

We conclude that hip resurfacing can be offered to patients with osteonecrosis.     

Subtrochanteric shortening osteotomy combined with cemented total hip arthroplasty for Crowe group IV hips

Background

Total hip arthroplasty (THA) is a challenging surgical procedure that can be used to treat severely dislocated hips. There are few reports regarding cemented THAs involving subtrochanteric shortening osteotomy (SSO), even though cemented THAs provide great advantages because the femur is generally hypoplastic with a narrow, deformed canal.

Purposes

We evaluated the utility of cemented THA with SSO for Crowe group IV hips, and assessed the relationship between leg lengthening and nerve injury. Our goal was to describe surgical techniques for optimizing surgical outcomes while minimizing the risk of nerve injury.

Methods

We retrospectively reviewed 34 cases of cemented THAs with transverse SSO for Crowe group IV. Prior to surgery, mean hip flexion was 93.1° (40°–130°). The mean follow-up period was 5.2 years (3–10 years).

Results

Bone union took an average of 7.7 months (3–24 months). Mean leg lengthening was 40.5 mm (15–70 mm) and was greater in patients without hip flexion contracture. None of the patients experienced any nerve injuries associated with leg lengthening, and radiographic evidence of loosening was not observed at the final follow-up.

Conclusions

SSO combined with cemented THA is an effective treatment for severely dislocated hips. Leg lengthening is not necessarily associated with nerve injuries, and the likelihood of this surgical complication may be related to the presence of hip flexion contracture.     

Cementless total hip arthroplasty for osteonecrosis of the femoral head in systemic lupus erythematosus: a study with 10–16 years of follow-up

Objectives

The purpose of the present study was to describe the long-term results of total hip arthroplasty (THA) for osteonecrosis of the femoral head (ONFH) in patients with systemic lupus erythematosus (SLE).

Methods

From 1994 to 2001, 18 cementless THAs (14 SLE patients) were included in the present study. Four hips (three patients) were lost to follow-up. The remaining 14 hips (11 patients) were available for evaluation. The mean follow-up period was 13.1 (range, 10.0–16.4) years. The follow-up rate was 77.8 %. The mean age at the time of surgery was 35.2 (range, 27.4–51.0) years.

Results

Mean preoperative Harris Hip Score was 37.4 (range, 17.1–63.1) points, which improved to 94.5 (range, 73.9–100) points at final follow-up. Two hips had dislocation and were treated successfully with closed reduction. No patient in this study group had deep venous thrombosis or pulmonary embolism. One hip had peroneal nerve palsy. No superficial or deep wound infection was observed. Two hips of two patients required reoperation due to dislodgement of a polyethylene insert. With revision of the acetabular component for any reason considered to be a failure, the 10-year survival rate was 93 % (95 % CI, 0.79–1).

Conclusion

We have reported the long-term results of THA for ONFH with SLE. Although several reports have noted that the results of THA for ONFH are less favorable than those for osteoarthritis, the long-term results of THA for ONFH with SLE were acceptable. THA is an acceptable option for patients with advanced-stage or an extended region of ONFH.     

Revision Surgery Occurs Frequently After Percutaneous Fixation of Stable Femoral Neck Fractures in Elderly Patients

Background

Femoral neck fractures are a major public health problem. Multiple-screw fixation is the most commonly used surgical technique for the treatment of stable femoral neck fractures.

Questions/purposes

We determined (1) the proportion of hips that had conversion surgery to THA, and (2) the proportion of hips that underwent repeat fracture surgery after percutaneous screw fixation of stable (Garden Stages I and II) femoral neck fractures in patients older than 65 years and the causes of these reoperations.

Methods

We performed a retrospective study of all patients older than 65 years with stable femoral neck fractures secondary to low-energy trauma treated surgically at our institution between 2005 and 2008. We identified 121 fractures in 120 patients older than 65 years as stable (Garden Stage I or II); all were treated with percutaneous, cannulated screw fixation in an inverted triangle without performing a capsulotomy or aspiration of the fracture hematoma at the time of surgery. The average age of the patients at the time of fracture was 80 years (range, 65–100 years). Radiographs, operative reports, and medical records were reviewed. Fracture union, nonunion, osteonecrosis, intraarticular hardware, loss of fixation, and conversion to arthroplasty were noted. Followup averaged 11 months (range, 0–5 years) because all patients were included, including those who died. The mortality rate was 40% for all patients at the time of review.

Results

Twelve patients (10%) underwent conversion surgery to THA at a mean of 9 months after the index fracture repair (range, 2–24 months); the indications for conversion to THA included osteonecrosis, nonunion, and loss of fixation. Two others had periimplant subtrochanteric femur fractures treated by surgical repair with cephalomedullary nails and two patients had removal of hardware.

Conclusions

Revision surgery after osteosynthesis for stable femoral neck fractures was more frequent in this series than previously has been reported. The reasons for this higher frequency of reoperation may be related to poor bone quality, patient age, and some technical factors, which leads us to believe other treatment options such as nonoperative management or hemiarthroplasty may be viable options for some of these patients.

Level of Evidence

Level IV, therapeutic study.     

Dislocation and its recurrence after revision total hip arthroplasty

Purpose

Dislocation is a leading cause of failure after revision total hip arthroplasty (THA). This study was conducted to examine the risk factors for dislocation as well as their recurrence after revision THA.

Methods

We retrospectively reviewed 178 revision THAs in 162 patients between 1998 and 2013. The mean patient age was 65.2 years at operation and the mean follow-up period was 6.7 years. Multivariate logistic regression was performed to identify risk factors for dislocation, and further comparison was made between patients with single and recurrent dislocations.

Results

Sixteen hips in 15 patients (9.0 %) dislocated at a mean of 9.1 months (range, 0–83 months) after revision THA. Multivariate analysis identified advanced age (odds ratio [OR]?=?2.94/10 years) and osteonecrosis of the femoral head (OR?=?7.71) as the independent risk factors for any dislocations. Risk factors for recurrent dislocations, which were observed in eight hips (50 %), were later dislocations (≥4 months) and lower BMI.

Conclusion

Dislocation is a serious problem after revision THA with multiple risk factors. Although our findings were limited to revision THAs done through posterolateral approach, recognition of these factors is helpful in patient education and surgical planning.