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.     

Hip para-articular fractures in patients over 100 years old]

Prompted by the rarity of successful treatments of patients more than 100 years of age, we report on two cases of fractures located near the hip joint. Both patients were operated urgently and discharged after a hospitalisation period of 5 and 6 weeks, respectively.     

Hip function in patients >55 years old: population reference values

The purpose of this study was to establish population values for hip function for patients of different ages using the validated WOMAC scoring system and the traditional Harris hip scoring system. A random sample of 184 individuals who had no prior history of hip or knee pain or pathology was evaluated. The average WOMAC scores for pain, function, and stiffness were 0.01, 1.8, and 0.4. The average Harris hip score was 94 +/- 8.2. No significant correlation was noted between the summary WOMAC score, the WOMAC stiffness or pain subscales, or the overall Harris hip score for any of the 3 age groups studied. Patients with complaints in other joints, such as the back and neck, had lower WOMAC and Harris hip scores. Adults who are healthy and do not have a prior history of hip or knee pathology do not show a significant decline in hip function as they grow older. A deterioration in the function of a total hip arthroplasty over time cannot be attributed solely to the aging process.     

Hip resurfacing: expectations and limitations

Background and purpose Long-term follow-up studies after total knee replacement (TKR) using an LCS rotating platform have shown survival rates of up to 97%. Few studies have evaluated short-term functional outcome and its improvement over time. We determined the time course of functional outcome as evaluated by the knee injury and osteoarthritis outcome score (KOOS) over the first 4 years after TKR using the LCS mobile bearing.

Patients and methods 50 unselected patients (mean age 70 (40–85) years, 33 women) with osteoarthritis in one knee underwent TKR with an LCS mobile bearing. Data were collected by an independent investigator preoperatively and at 6 weeks, 3 months, 6 months, 1 year, 2 years and 4 years postoperatively. KOOS, a self-assessment function score validated for this purpose, and range of motion (ROM) were determined at all follow-ups.

Results The mean KOOS pain score increased from 43 before surgery to 66 at 6 weeks and 88 at 2 years. It was 84 at 4 years. The mean KOOS activities of daily living score (ADL) increased from 49 before surgery to 73 at 6 weeks, then gradually to 90 at 2 years. It decreased to 79 at 4 years. Mean passive ROM was 112° before surgery, 78° at departure from hospital, and then gradually increased to 116° at 2 years and 113° at 4 years.

Interpretation Recovery after TKR is time-dependent. Most of the expected improvement in pain and function is achieved at 6 months postoperatively, but some further improvement can be expected up to 2 years postoperatively. ROM will also gradually improve up to 2 years after TKR, and reach the same level as before surgery.     

Hip resurfacing: expectations and limitations

Two cases of epiphyseal osteoid osteoma presented with a 1-2 year history of monarthritis with swelling and impaired function of the knee and ankle, respectively. In both cases, removal of the lesion resulted in complete recovery.     

全髋表面置换术治疗强直性脊柱炎

目的：研究金属对金属全髋表面置换术治疗强直脊柱炎性髋关节病的近期疗效,探讨该病行全髋表面置换术的适应证和技术要点。方法：对2006年2月至2008年4月11例（15髋）行全髋表面置换术的强直性脊柱炎性髋关节病患者进行随访,男9例,女2例;年龄16～53岁,平均32．5岁。对手术前后关节疼痛、活动度、畸形矫正、松动及功能的改善进行对比研究,根据Harris评分系统进行比较,分析强直性脊柱炎患者行全髋表面置换术的可行性和技术难点。结果：失访1例,实际得访10例（14髋）,10例疼痛缓解：随访时间平均16．2个月（8-34个月）。术前Harris评分平均（30．9±3．4）分（2-47分）,术后16个月平均（85．1±3．1）分（46-94分）;术前屈髋度0°-75°,术后16个月35°～105°;术前外展度0°-30°,术后16个月15°～55°。评价：优10髋,良3髋,差1髋。9例术后生活自理,其中6例可奔跑。1例疼痛部分缓解,关节功能恢。复差。无术后股骨颈骨折发生,无异位骨化。结论：经过适当患。者选择,全髋表面置换术治疗强直性脊柱炎性髋关节病可以获得满意的疗效,术中的精细操作和个体化手术设计至关重要。     

A medium-term comparison of hybrid hip replacement and Birmingham hip resurfacing in active young patients

We compared the medium-term clinical and radiological results of hybrid total hip replacement (THR) with metal-on-metal Birmingham hip resurfacing (BHR) in two groups of 54 young patients matched for age, gender, body mass index and pre-operative levels of activity. The clinical outcome was assessed by the University of California, Los Angeles (UCLA) activity score, the Oxford Hip Score (OHS) and the EuroQol scores. Radiologically, all hips were assessed for migration and osteolysis, the hybrid THRs for polyethylene wear and the BHRs for a pedestal sign. The mean follow-up of the patients with a hybrid THR was ten years and for those with a BHR, nine years. Four patients with a hybrid THR and one with a BHR had died. In each group five were lost to follow-up. The revision rate of the hybrid THRs was 16.7% (9 of 54) and of the BHRs 9.3% (5 of 54) (p = 0.195). Radiographs of a further eight hybrid THRs demonstrated wear and osteolysis, and they await revision (p = 0.008). Of the unrevised BHRs 90% had radiological changes, of which approximately 50% had progressed over the previous four years. All hybrid THRs demonstrated linear polyethylene wear with a mean of 1.24 mm (0.06 to 3.03). The BHRs recorded superior OHS (p = 0.013), UCLA (p = 0.008), and EuroQol visual analogue scores (p = 0.009). After nine years, patients with BHRs remained more active and had a lower rate of revision than those with hybrid THRs. Both groups demonstrated progressive radiological changes at medium-term follow-up.     

Transitional cell carcinoma of bladder in patients under thirty years of age.

Seventy-nine cases of transitional cell carcinoma of the bladder in the age group under thirty years have been reviewed. The diagnosis and treatment are the same as in the older age group. The tumors are usually of low grade and low stage, but they can become more aggressive and more malignant. Contrary to previously held beliefs that transitional cell tumors in the younger age group rarely if ever recur, this series had a recurrence rate of 13.9 per cent with several patients having multiple recurrences. Therefore, the follow-up care of these patients must be vigilant and persistent.     

Cementless total knee replacement in patients 50 years old and under

In this article, the authors present their initial experience with a cementless total knee prosthesis implanted in a young, active group of patients. The results compare favorably to reported cemented series.     

Hip instability in myelomeningocele: 158 patients followed for 15 years

In 158 patients with myelomeningocele, the prevalence of hip dislocation at birth and subluxation or dislocation of unoperated on hips at 2 and 15 years of age were assessed. In neonates examined during the first 10 weeks of life, 10 percent of the hips were dislocated. In children with a thoracic or L1-2 neurologic level, the cumulative incidence of dislocated hips increased from 8 to 26 percent and subluxations from 33 to 45 percent. In children with L3 and L4 levels, one fourth of the hips had dislocations and nearly half subluxations. At L5 and the sacral motor level, dislocations did not occur, but one fifth of the hips had subluxations. Children with L3 or L4 neurologic levels had bilateral hip dislocation at an earlier age than those with higher levels of paralysis. There appears to be no risk of developing hip dislocation at neurologic levels below L4, and spasticity promotes hip dislocation above L3.     

Hip resurfacing: For the right patient and surgeon

Hip resurfacing offers several advantages over traditional total hip replacement, such as femoral bone preservation, larger head size, higher activity level, and easier revision options. Now, that hip resurfacing has reached a mature state in its practice, there are substantial data that identifies patients who are most likely to benefit from these advantages. There are, however, risks that are inherent to the metal-on-metal articulation of a hip resurfacing implant. For example, there is a danger of edge loading with the hard-on-hard bearing, leading to excess production of wear debris (metallosis). Furthermore, there is the possibility of an immunologic reaction to the metal wear particles, leading to swelling, osteolysis, and potential tissue destruction. Several studies and national registries have found that male patients with a diagnosis of osteoarthritis, good bone quality, large bone size, and normal anatomy are the cohort who has the highest success rate with hip resurfacing. These patients will also likely achieve a higher activity level, making it worthwhile for them to accept the potential risks of a metal-on-metal implant. Hip resurfacing is also generally accepted to be a more technically difficult procedure than traditional hip replacement due to the need to expose the acetabulum while retaining the native femoral head and neck. Therefore, surgeons need special training to be facile with the procedure and sufficient surgical volume to advance beyond the learning curve. The metal-on-metal bearing is less forgiving than other materials and thus the placement of the implant needs to be more precise. Thus, hip resurfacing will have the greatest chance of success in the right patient and when performed by the right surgeon.