The Effect of Surgeon and Hospital Volume on Total Hip Arthroplasty Patient-Reported Outcome Measures: An American Joint Replacement Registry Study

Time to Achieve the Minimal Clinically Important Difference in Primary Total Hip Arthroplasty: Comparison of Anterior and Posterior Surgical Approaches

BACKGROUND

Controversy remains over outcomes between total hip arthroplasty approaches. This study aimed to compare the time to achieve the minimal clinically important difference (MCID) for the Hip Disability and Osteoarthritis Outcome Score-Physical Function Short Form (HOOS-PS) and the Patient-Reported Outcomes Measurement Information System (PROMIS) Global-Physical for patients who underwent anterior and posterior surgical approaches in primary total hip arthroplasty.

METHODS

Patients from 2018 to 2021 with preoperative and postoperative HOOS-PS or PROMIS Global-Physical questionnaires were grouped by approach. Demographic and MCID achievement rates were compared, and survival curves with and without interval-censoring were used to assess the time to achieve the MCID by approach. Log-rank and weighted log-rank tests were used to compare groups, and Weibull regression analyses were performed to assess potential covariates.

RESULTS

A total of 2,725 patients (1,054 anterior and 1,671 posterior) were analyzed. There were no significant differences in median MCID achievement times for either the HOOS-PS (anterior: 5.9 months, 95% confidence interval [CI]: 4.6 to 6.4; posterior: 4.4 months, 95% CI: 4.1 to 5.1, P = .65) or the PROMIS Global-Physical (anterior: 4.2 months, 95% CI: 3.5 to 5.3; posterior: 3.5 months, 95% CI: 3.4 to 3.8, P = .08) between approaches. Interval-censoring revealed earlier times of achieving the MCID for both the HOOS-PS (anterior: 1.509 to 1.511 months; posterior: 1.7 to 2.3 months, P = .87) and the PROMIS Global-Physical (anterior: 3.0 to 3.1 weeks; posterior: 2.7 to 3.3 weeks, P = .18) for both surgical approaches.

CONCLUSIONS

The time to achieve the MCID did not differ by surgical approach. Most patients will achieve clinically meaningful improvements in physical function much earlier than previously believed.

LEVEL OF EVIDENCE

Level III, Retrospective Comparative Study.

Influence of Surgeon Experience and Clinic Volume on Subjective Knee Function and Revision Rates in Primary ACL Reconstruction: A Study from the Swedish National Knee Ligament Registry

Background

Anterior cruciate ligament reconstruction (ACLR) performed by high-volume surgeons/clinics has been associated with increased graft individualization and decreased operating times, complication rates, and total costs.

Purpose

To investigate the influence of surgeon/clinic volume on subjective knee function and revision surgery rates at 2 years after primary ACLR.

Study Design

Cohort study; Level of evidence, 3.

Methods

Data from the Swedish National Knee Ligament Registry were used to study patients who underwent primary ACLR between 2008 and 2019. Surgeons/clinics were categorized based on a combination of total caseload volume (cutoff: 50 ACLRs/surgeon, 500 ACLRs/clinic) and annual volume (cutoff: 29 ACLRs/year/surgeon, 56 ACLRs/year/clinic). The thresholds of minimal important change (MIC), Patient Acceptable Symptom State (PASS), and treatment failure (TF) relative to the Knee injury and Osteoarthritis Outcome Score (KOOS) and KOOS4 (mean score of the KOOS Pain, Symptoms, Sports/Rec, and QoL subscales) were applied. Adjusted multivariable logistic regression was performed to assess variables influencing the MIC, PASS, or TF of the KOOS and KOOS4. Adjusted Cox regression analysis was conducted to determine the hazard ratio of subsequent ACLR.

Results

Of 35,371 patients, 16,317 had 2-year follow-up outcome data and were included. Patients who underwent primary ACLR by high-volume surgeons had significantly higher MIC and PASS rates and lower TF rates when compared with patients who underwent the procedure by low-volume surgeons: MICKOOS4: 70.6% vs 66.3%; PASSKOOS4: 46.0% versus 38.3%; and TFKOOS4: 8.7% versus 11.8% (all P < .02). Significantly decreased odds of achieving MICKOOS4 (OR, 0.74; 95% CI, 0.62-0.88) and PASSKOOS4 (OR, 0.71; 95% CI, 0.60-0.84) were found for ACLRs performed by low-volume surgeons. Clinic volume did not influence the odds of reaching MIC, PASS, or TF. Overall, 804 patients (2.3%) underwent subsequent ACLR at <2 years, with significantly higher revision rates among patients operated on at high-volume clinics (2.5% vs 1.7%; P < .001). However, in the adjusted Cox regression, surgeon/clinic volume had no influence on subsequent ACLR rates. High-volume surgeons/clinics had decreased time to surgery, operating time, perioperative complication rates, and use of thromboprophylaxis and nonroutine antibiotics (P < .001).

Conclusion

Patients who underwent primary ACLR by high-volume surgeons experienced increased improvement and satisfaction regarding subjective knee function. Factors other than surgical volume influenced subsequent surgery rates. Patients might benefit from undergoing primary ACLR by high-volume providers.

Most Military Arthroplasty Surgeons Have a Low Volume Practice in the Military Health System

Background

The purpose of this study is to investigate hospital and surgeon joint arthroplasty volume in the Military Health System (MHS). A secondary aim is to look at interruption in physician practice during the study period.

Methods

Review of all patients undergoing hip or knee arthroplasty in the MHS over >5-year period to examine hospital and surgeon volume for total joint arthroplasty (TJA). We stratified hospital and surgeon volume into low, medium, and high volumes.

Results

Fifty surgeons performed at least 50 hip and/or knee arthroplasties during this period. These surgeons accounted for 75% of TJA in the MHS. When stratified by cases per year, the median primary total hip arthroplasty (THA) per year was 31.4 and primary total knee arthroplasty (TKA) was 47.3 per year. Regarding the volume threshold for primary and revision TJA, all hospitals were classified as having low volumes for both THA and unicompartmental knee arthroplasty/TKA. There were 0 high volume, 7 (21.9%) medium volume, and 25 (78.1%) low volume THA surgeons; there was 1 high volume TKA surgeon, 17 (34.7%) medium volume, and 31 (63.3%) low volume TKA surgeons. The average duration of clinical activity for fellowship-trained surgeons over the study period was 4.0 years, and the average duration of clinical inactivity was 263.7 days (17.9% of practice period).

Conclusions

The highest-volume military arthroplasty surgeons have low volume when compared to their civilian colleagues. There are also long periods of clinical practice interruption. These findings stress the need to establish civilian-DOD or DOD-VA working relationships so that MHS patients experience the best possible care by high-volume surgeons in high-volume surgical centers.

Recovery Curves for Patient Reported Outcomes and Physical Function After Total Hip Arthroplasty

INTRODUCTION

Patient reported outcome measures (PROMs) are frequently used for evaluating patient satisfaction and function following total hip arthroplasty (THA). Functional measures along with chronologic modeling may help set expectations perioperatively. Our goal was to define the trajectory of recovery and function in the first year following THA.

METHODS

Prospective data from 1,898 patients in a multicenter study was analyzed. The PROMs included the Hip disability and Osteoarthritis Score for Joint Replacement (HOOS-JR) and EuroQol-5 dimension (EQ5D). Physical activity was recorded on a wearable technology. Data was collected pre-operatively and at one, three, six, and twelve months post-operatively. Generalized estimating equations were used to evaluate outcomes over time.

RESULTS

Significant improvement occurred between pre- and post-operative time points for all PROMs. The PROMs showed the greatest proportional recovery within the first month post-operatively, each improving by at least one minimal clinically important difference (MCID). Daily steps and flights of stairs took longer to reach at least one MCID (three months and one year, respectively). Gait speed and walking asymmetry returned to baseline by three months, but did not reach a MCID of improvement by one-year.

CONCLUSION

Patients can be counseled that the greatest proportional improvement in PROMs is within one month after THA, while function surpasses pre-operative baselines by three-months, and gait quality may not improve until after one-year. This can help set realistic expectations and target interventions toward patients deviating from the norm.