Patient-Reported Outcomes After Revision of Metal-on-Metal Total Bearings in Total Hip Arthroplasty

Mid-term outcomes of uncemented or cemented arthroplasty revision following metal-on-metal total hip arthroplasty failure: a retrospective observational study

Objective

To retrospectively compare the mid-term outcomes of uncemented or cemented total hip arthroplasty (THA) revision for prior primary metal-on-metal (MoM) THA failure.

Methods

Data from 278 patients (278 hips) who underwent uncemented THA (UTHA) or cemented THA (CTHA) for prior primary MoM-THA failure from 2006 to 2016 were retrospectively analysed. Follow-up was performed 6 months, 1 year, 2 years, and then every 2 years after conversion. The mean follow-up time was 96 months (range, 64–128 months). The primary endpoint was the modified Harris hip score (HHS). The secondary endpoint was the major orthopaedic complication rate.

Results

The HHS showed significantly greater differences in the CTHA than UTHA group 12 months after conversion. From the 12th month after conversion to the final follow-up, CTHA yielded better functional outcomes than UTHA. There were significant differences between the UTHA and CTHA groups in the rates of re-revision (14.4% vs. 4.9%, respectively), aseptic loosening (17.3% vs. 6.8%, respectively), and periprosthetic fracture (11.5% vs. 3.9%, respectively).

Conclusion

CTHA has more advantages than UTHA in terms of improving functional outcomes and decreasing the major orthopaedic complication rate.

Revision of failed metal-on-metal total hip arthroplasty using cemented arthroplasty: a mean 10-year follow-up of 157 consecutive patients

OBJECTIVE

This study was performed to assess the outcomes of Asian patients who underwent conversion from metal-on-metal total hip arthroplasty (MoM-THA) to cemented THA (CTHA).

METHODS

One hundred and fifty-seven consecutive patients (157 hips) who underwent CTHA following primary MoM-THA from January 2005 to February 2015 were retrospectively analysed. The primary endpoints were the clinical outcomes. Follow-ups occurred at 3 months, 6 months, 1 year, 2 years, and then every 2 years following revision of MoM-THA.

RESULTS

The mean follow-up after conversion was 10 years (range, 5-14 years). Statistically significant improvements in the mean Harris hip score were observed between the preoperative and final follow-up evaluations (62.71 ± 13.85 vs. 84.03 ± 16.21, respectively). The major orthopaedic complication rate was 16.5% (26/157). Six (3.8%) patients underwent revision at a mean of 3.5 ± 1.3 years after conversion, predominantly because of prosthesis loosening or recurrent dislocation. Nine (5.7%) patients developed prosthesis loosening at a mean of 2.6 ± 1.1 years following conversion, two of whom requested revision surgery. Eleven (7.0%) patients developed prosthesis dislocation, four of whom requested revision surgery.

CONCLUSION

CTHA may yield favourable functional outcomes and a reduced rate of major orthopaedic complications.

Use of Computerized Adaptive Testing to Develop More Concise Patient-Reported Outcome Measures

Background

Patient-reported outcome measures (PROMs) are essential tools that are used to assess health status and treatment outcomes in orthopaedic care. Use of PROMs can burden patients with lengthy and cumbersome questionnaires. Predictive models using machine learning known as computerized adaptive testing (CAT) offer a potential solution. The purpose of this study was to evaluate the ability of CAT to improve efficiency of the Veterans RAND 12 Item Health Survey (VR-12) by decreasing the question burden while maintaining the accuracy of the outcome score.

Methods

A previously developed CAT model was applied to the responses of 19,523 patients who had completed a full VR-12 survey while presenting to 1 of 5 subspecialty orthopaedic clinics. This resulted in the calculation of both a full-survey and CAT-model physical component summary score (PCS) and mental component summary score (MCS). Several analyses compared the accuracy of the CAT model scores with that of the full scores by comparing the means and standard deviations, calculating a Pearson correlation coefficient and intraclass correlation coefficient, plotting the frequency distributions of the 2 score sets and the score differences, and performing a Bland-Altman assessment of scoring patterns.

Results

The CAT model required 4 fewer questions to be answered by each subject (33% decrease in question burden). The mean PCS was 1.3 points lower in the CAT model than with the full VR-12 (41.5 ± 11.0 versus 42.8 ± 10.4), and the mean MCS was 0.3 point higher (57.3 ± 9.4 versus 57.0 ± 9.6). The Pearson correlation coefficients were 0.97 for PCS and 0.98 for MCS, and the intraclass correlation coefficients were 0.96 and 0.97, respectively. The frequency distribution of the CAT and full scores showed significant overlap for both the PCS and the MCS. The difference between the CAT and full scores was less than the minimum clinically important difference (MCID) in >95% of cases for the PCS and MCS.

Conclusions

The application of CAT to the VR-12 survey demonstrated an ability to lessen the response burden for patients with a negligible effect on score integrity.

Revision total hip arthroplasty for metal-on-metal failure

Metal-on-metal (MoM) arthroplasty systems became popular in the early-2000s due to presumed advantages of improved wear characteristics and superior stability. However, subsequent reports of abnormal soft-tissue reactions to MoM implants and national registry data reporting high failure rates raised concerns. Early outcomes of revision total hip arthroplasty (THA) for adverse reaction to metal debris (ARMD) were poor, leading to development of surveillance programs and a trend towards early revision surgery. Patients with MoM arthroplasties require surveillance, comprehensive history and physical examination, imaging with ultrasound or magnetic resonance imaging (MRI), and laboratory evaluation including metal ion levels. Operative strategies for revision THA vary from exchange of modular components to extensive debridement and reconstruction with revision components. Surgeons should be aware of the increased risks of dislocation and infection following revision THA for ARMD. However, there is growing evidence that early revision surgery prior to extensive soft tissue destruction results in improved outcomes and decreased re-operation rates. It is estimated that >1 million MoM articulations have been implanted, with a large proportion still in situ. It is imperative to understand the aetiology, presentation, and management strategies for these patients to optimise their clinical outcomes.

Revision of Failed Metal-on-Metal Total Hip Arthroplasty: Midterm Outcomes of 203 Consecutive Cases

BACKGROUND

Metal-on-metal (MoM) revisions have shown high rates of complications from aseptic loosening, deep infection, and dislocation. The purpose of this study is to report on outcomes and complications of a large consecutive series of patients who were revised for failed MoM total hip arthroplasty (THA).

METHODS

We evaluated 188 patients (203 hips) who underwent revisions of failed MoM THA. Mean age at the revision was 60 years old. Gender was female in 112 hips (55%) and male in 91 hips (45%). Mean interval to failure after primary THA was 4.9 years (range, 0-18 years). The acetabular component was revised in 183 cases (92%). Clinical outcomes assessed included pain score and Harris hip score.

RESULTS

Mean follow-up from revision was 4.2 years. Harris hip score improved from 53.6 pre-revision to 73.5 at most recent follow-up (P < .001). Pain level significantly improved from 17.2 pre-revision to 32.8 post-revision (P < .001). Reoperations occurred in 28 (14%) hips. Re-revision was required in 16 hips (7.9%). The most common reasons for re-revision were aseptic loosening (5), dislocation (3), infection (2), and iliopsoas tendonitis (2). Re-revision was significantly higher in cases of pseudotumor. There was no difference in survival with ultraporous cups. Three hips required re-revision to custom triflange components. All-cause survival was 90.5% at 4.2 years. Metal ion levels significantly declined after revision.

CONCLUSION

Revisions of failed MoM THA showed improvements in clinical outcomes, but present significant surgical challenges and complications especially in cases with soft tissue damage and pseudotumor.

The Outcome of Revision Surgery for Failed Metal-on-Metal Total Hip Arthroplasty

BACKGROUND

Metal-on-metal total hip arthroplasties (MoM THAs) are frequently revised, though there is a paucity of functional outcome data. We report on outcomes and prognostic factors predictive of outcome from the largest series of MoM THA revisions to date.

METHODS

A single-center consecutive series of revisions from MoM THAs was identified. The cohort was divided by the presence or absence of symptoms prior to revision. The primary outcome was functional outcome (Oxford Hip Score [OHS]). Secondary outcomes were complication data, pre-revision and post-revision blood metal ions, and modified Oxford classification of pre-revision magnetic resonance imaging.

RESULTS

One hundred eighty revisions at median follow-up of 5.48 years were identified. Median OHS improved from 29 to 37 with revision (P < .001). Symptomatic patients experienced the greatest functional benefit (ΔOHS 6.5 vs 1.4, P = .012), while the function of asymptomatic patients was unaffected by revision (P = .4). Use of a cobalt-chromium-containing bearing surface at revision and increased body mass index were predictive of poor functional outcome.

CONCLUSION

Symptomatic patients experience greater functional benefit from revision surgery but do not regain the same level of function as patients who were asymptomatic prior to revision. Body mass index and use of cobalt-chromium-containing bearing surfaces are prognostic for poor functional outcome.

Cemented versus uncemented femoral component total hip arthroplasty in elderly patients with primary osteoporosis: retrospective analysis with 5-year follow-up

Objective

To compare medium-term clinical and radiological outcomes of primary unilateral uncemented (UN) or cemented (CE) femoral component total hip arthroplasty (THA) in elderly patients with osteoporosis.

Methods

Consecutive patients with osteoporosis who underwent primary unilateral UN or CE THAs at our institution from 2006 to 2013 were retrospectively reviewed. All consecutive procedures were managed by high-volume surgeons, using UN or CE THA approaches. Follow-up assessments occurred at 1, 3, 6, 9, and 12 months postoperatively, and yearly thereafter. Patient-related functional outcomes were assessed using the Harris Hip Score (HHS). Primary and secondary endpoints were early revision (<5 years) and functional outcome.

Results

In total, 496 primary unilateral THAs (CE, n = 184; UN, n = 182) were assessed with a median follow-up period of 75 months (range, 65–86 months). From 3 months after surgery to the final follow-up, HHS was consistently superior in the CE group. Respective prosthetic loosening rates in the UN and CE groups were 26.4% and 16.8% at a minimum of 5 years. There was a significant difference in rate of early revision (7.6% CE vs. 14.8% UN).

Conclusion

Compared with UN THA, CE THA exhibits a superior outcome in elderly patients with primary osteoporosis.

Perioperative factors associated with increased length of stay after revision of metal-on-metal total hip arthroplasty

Objective

To investigate patient factors influencing length-of-stay (LOS) after revision metal-on-metal (MoM) total hip arthroplasty (THA).

Methods

We reviewed 23 hips undergoing revision of a MoM THA with minimum 2-year follow-up. A multiple linear regression was calculated to predict LOS using multiple variables.

Results

Average length of stay (LOS) was 2.1 days. Multiple linear regression analysis identified a significant correlation between presence of an abductor injury (beta = 0.8886; p < 0.0001), patient age (beta = -0.4452, p = 0.0083), and pre-revision head size (beta = 0.4082; p = 0.0172) with LOS (R² = 0.6351, p = 0.0002).

Conclusion

Patients with abductor injury, larger femoral heads, and younger age are at risk for longer LOS.