Revision Total Hip Arthroplasty in Patients With Ankylosing Spondylitis: Long-Term Results

Revision total hip arthroplasty in patients with ankylosing spondylitis: Mid-term results

BACKGROUND

Few studies have reported on the outcome of revision total hip arthroplasty (THA) for ankylosing spondylitis (AS). Therefore, we sought to investigate the clinical and radiographic outcomes of revision THA in patients with AS.

HYPOTHESIS

The mid-term outcome of revision THA in AS patients was comparable to conventional revision THA.

MATERIALS AND METHODS

Forty-one patients with AS who underwent revision THA (on a total of 51 hips) between April 2004 and June 2018 were included. The mean follow-up duration was 7.5±3.6 years (3.0-15.8 years). Clinical outcomes were assessed using the Bath Ankylosing Spondylitis Functional Index (BASFI), Harris Hip Score (HHS), and the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index. Complications were assessed at each follow-up. Radiological outcomes were examined by reviewing postoperative plain radiographs.

RESULTS

Significant improvements were seen in BASFI, HHS, and WOMAC scores (p<0.01). Postoperative combined range of motion (ROM) was 128.9±45.3° (range, 60-300°). Complications included heterotopic ossification, periprosthetic fractures, aseptic loosening, osteolysis, reinfection, residual pain or stiffness, delayed wound healing, numbness, deep vein thrombosis, leg length discrepancy, and posterior dislocation. Five (9.8%) of the 51 hips were treated with re-revision due to aseptic loosening, re-infection, or re-fracture. The incidence of dislocation was 1.9% at 7.5 years. Implant survival for all reasons was estimated to be 96.3% at 5 years, 85.9% at 10 years and 61.0% at 15 years. Forty-two (82.4%) hip revisions were rated "satisfactory" or "very satisfactory" by the patients.

CONCLUSIONS

The mid-term result of revision THA for patients with AS is comparable to conventional revisions in terms of implant survival, despite high complication rates. The benefit-risk ratio of these indications is acceptable but deserves specific information for these patients.

LEVEL OF EVIDENCE

IV; case series.

Fourth‐Generation Ceramic‐on‐Ceramic THA in Patients with Ankylosing Spondylitis: A Minimum 10‐Year Follow‐Up

Objective

To report the long‐term outcomes of total hip arthroplasty (THA) with fourth‐generation ceramic‐on‐ceramic (CoC) bearing in patients with ankylosing spondylitis (AS).

Methods

We retrospectively identified 180 primary THAs performed in 110 patients with AS, including 100 (90.9%) men and 10 women (9.1%), from 2009 to 2011.The mean age of the patients at surgery was 33 years (range, 16 to 65 years). Cementless prostheses with fourth‐generation CoC bearings were used in all patients. Survivorship of the implants and postoperative complications were calculated. Functional improvement was assessed by the hip flexion‐extension range of motion (ROM) and Harris hip score (HHS). A special noise assessment questionnaire was performed at the last follow‐up. The cumulative incidence of noise was calculated by the Kaplan–Meier method with 95% confidence intervals (CIs). Clinical characteristics and functional outcomes were compared in the hips with noise to those without noise.

Results

The mean follow‐up was 11 years (range, 10 to 12 years), and survivorship of the implants was 99.4% at the most recent follow‐up. The complications included dislocation (one hip, 0.6%), periprosthetic joint infection (one hip, 0.6%), mild to moderate pain (five hips, 2.8%), heterotopic ossification (12 hips, 6.7%), and noise (52 hips, 28.9%). The flexion‐extension ROM improved significantly with a median from 10° (range, 0 ~ 130°) to 100° (30 ~ 130°) after THA (p < 0.001), and the HHS increased significantly from 41 ± 20 to 90 ± 8 (p < 0.001). The cumulative incidence of noise at 0.5, 5, and 10 years was 6.1% (95% CI, 2.6 ~ 9.6), 16.7% (95% CI, 11.2 ~ 22.1), and 28.9% (95% CI, 22.2 ~ 35.5), respectively, and that of squeaking at 0.5, 5, and 10 years was 4.4% (95% CI, 1.4 ~ 7.4), 13.3% (95% CI, 8.4 ~ 18.3), and 23.9% (95% CI, 17.6 ~ 30.1), respectively. None of the patients with noise generation in the hip reported it affecting daily activities or causing dissatisfaction. No differences in age, sex, BMI, disease duration, bilateral THA, the frequency of bony ankylosis, the proportion of using a 36‐mm‐diameter femoral head, pre/postoperative flexion‐extension ROM, or pre/postoperative HHS were found between hips with noise and those without noise (p > 0.05).

Conclusion

THAs with fourth‐generation CoC bearings exhibit excellent long‐term survival and clinical outcomes in patients with AS, with a very low dislocation rate. The incidence of noise associated with CoC bearings in THA performed in patients increases over time, but it does not affect postoperative hip function or daily activities.

Dysregulation of SAA1, TUBA8 and Monocytes Are Key Factors in Ankylosing Spondylitis With Femoral Head Necrosis

Introduction

The mechanism of ankylosing spondylitis with femoral head necrosis is unknown, and our study aimed investigate the effects of genetic and immune cell dysregulation on ankylosing spondylitis.

Materials and Methods

The protein expression of all ligaments in ankylosing spondylitis with femoral head necrosis was obtained using label-free quantification protein park analysis of six pairs of specimens. The possible pathogenesis was explored using differential protein analysis, weighted gene co-expression network analysis, recording intersections with hypoxia-related genes, immune cell correlation analysis, and drug sensitivity analysis. Finally, routine blood test data from 502 AS and 162 healthy controls were collected to examine immune cell differential analysis.

Results

SAA1 and TUBA8 were significantly expressed differentially in these two groups and correlated quite strongly with macrophage M0 and resting mast cells (P < 0.05). Routine blood data showed that monocytes were significantly more expressed in AS than in healthy controls (P < 0.05). SAA1 and TUBA8 were closely related to the sensitivity of various drugs, which might lead to altered drug sensitivity.

Conclusion

Dysregulation of SAA1, TUBA8 and monocytes are key factors in ankylosing spondylitis with femoral head necrosis.

Hip Replacement in Ankylosing Spondylitis Patients with Advanced Hip Involvement: Factors Associated with Bilateral Total Hip Arthroplasty

BACKGROUND

This study aimed to compare the clinical data of ankylosing spondylitis (AS) patients who underwent unilateral and bilateral total hip arthroplasty (THA) due to advanced hip involvement. Furthermore, to determine the factors associated with bilateral THA.

METHODS

Utilizing a single-institution database, we selected 373 consecutive AS patients undergoing primary THA from 2012 to 2017 and compared the clinical characteristics and anti-tumor necrosis factor (TNF) therapy of the patients who underwent unilateral and bilateral THA. Logistic regression was used to identify factors associated with bilateral THA.

RESULTS

Bilateral THA was performed in 67.3% (n=251) of the patients. Male patients had a higher frequency of undergoing bilateral THA compared with female ones (P<0.05). The proportion of the patients who had bilateral onset in hips, administration of TNF inhibitors, flexion contracture in the hip, and a BASRI-hip score of 4 was significantly higher in patients with bilateral THA than that with unilateral THA (P<0.05). Patients with bilateral THA experienced longer disease duration than those with unilateral THA (P<0.05). The results of the logistic regression showed that factors related to bilateral THA were bilateral onset in hips, administration of TNF inhibitors, a BASRI-hip score of 4, and an erythrocyte sedimentation rate (ESR) level (P<0.05).

CONCLUSION

Bilateral THA is more common in AS patients with advanced hip involvement. Bilateral onset in hips, a BASRI-hip score of 4, and a higher level of ESR are risk factors associated with bilateral THA, while anti-TNF therapy is a protective factor reducing the progression of hip involvement to bilateral THA.