What's New in Hip Replacement

A bibliometric analysis of classic publications in web of science category of orthopedics

Background

The past century has witnessed the rapid development of operation technique, surgical instruments, and knowledge of the diseases in orthopedics. In the academic history, a number of classic papers boosted the advancement for surgery. In this paper, we performed a bibliometric analysis, aiming to determine the most influential studies within the field.

Methods

Articles were searched from the publication year of 1900 to 2016 according to the Science Citation Index Expanded database of the Clarivate Analytics Web of Science Core Collection database. Two citation indicators TC_year and C_year were employed to characterize the classic articles and the articles were identified and analyzed.

Results

A total of 30 classic articles with TC₂₀₁₆ ≥ 1000 in Web of Science category of orthopedics were identified, all written in English between 1961 and 2007 by nine countries. The minimal value of TC₂₀₁₆ was 1010; the maximum 3570; and the average 1591. Thirty classic articles were published in eight journals that were listed in the Web of Science category of orthopedics in 2016, and in two other orthopedics journals that were no longer tracked by Web of Science category of orthopedics as of 2016. Among the top 10 cited articles in both TC₂₀₁₆ and C₂₀₁₆, five articles barely received attention in the first few years after their publication, while they became cited more and more frequently in the last decade.

Conclusion

This study evaluated the development and trend of orthopedics research by adopting bibliometric analysis. It serves as a guide for investigators in the future research.

The effect of surgical approach on gait mechanics after total hip arthroplasty

BACKGROUND

Few studies have compared the biomechanical outcomes of different surgical approaches for hip arthroplasty. The purpose of this study was to compare hip, pelvic, and trunk kinematics and kinetics between individuals who underwent a posterior or anterolateral approach.

METHODS

Forty-five individuals between 40 and 80 years old underwent motion analysis during overground gait prior to hip arthroplasty and 3 months after surgery. Walking speed, hip flexion angle, hip extension angle, adduction angle and moment, trunk angle, trunk lean, and pelvis drop were compared between approaches.

FINDINGS

There were 30 subjects in the posterior group and 15 subjects in the anterolateral group. The groups did not change differently over time as there were no significant interaction effects. However, there were main effects for time; walking speed increased 19.9% (p < .001), hip flexion angle increased 3.3 degrees (p = 0.014) and peak hip extension increased 4.5 degrees (p = .001), and peak hip adduction significantly increased 1.9 degrees (p = .004) for the sample as a whole. Trunk angle (p = .283) and trunk lean (p = .401) did not significantly change between time points, but there was a significant increase in pelvic drop (p = .003).

INTERPRETATION

Surgical approach did not affect biomechanical outcomes 3 months after arthroplasty. Both groups showed improvement in sagittal plane hip kinetics and kinematics. However, increased pelvic drop may be indicative of residual hip weakness in both groups.

Are Readmissions After THA Preventable?

BACKGROUND

Readmissions after total joint arthroplasty have become a key quality measure in elective surgery in the United States. The Affordable Care Act includes the Hospital Readmission Reduction Program, which calls for reduced payments to hospitals with excessive readmissions. This policy uses a method to determine excess readmission ratios and calculate readmission payment adjustments to hospitals, however, it is unclear whether readmission rates are an effective quality metric. The reasons or conditions associated with readmission after elective THA have been well established but the extent to which readmissions can be prevented after THA remains unclear.

QUESTIONS/PURPOSES

(1) Are unplanned readmissions after THA associated with orthopaedic or medical causes? (2) Are these readmissions preventable? (3) When during the course of aftercare are orthopaedic versus medical readmissions more likely to occur?

METHODS

We retrospectively evaluated all 1096 elective THAs for osteoarthritis performed between January 1, 2011 and June 30, 2014 at a major academic medical center. Of those, 69 patients (6%) who met inclusion criteria were readmitted in our healthcare system within 90 days of discharge after the index procedure during the study period. Fifty patients were readmitted within 30 days of discharge after the index procedure (5%). We defined a readmission as any unplanned inpatient or observation status admission to the hospital spanning at least one midnight. A panel of physicians not involved in the care of these patients used available criteria and existing consensus guidelines to evaluate the medical records, radiographs, and operative reports to identify whether the underlying reason for readmission was orthopaedic versus medical. They subsequently were classified as either nonpreventable or potentially preventable readmissions, based on any care that may have occurred during the index hospitalization. To make such determinations, consensus specialty society guidelines were used whenever possible for each readmission diagnosis.

RESULTS

A total of 50 of 1096 patients (5% of those who underwent THA during the period in question) were readmitted within 30 days and 69 of 1096 (6%) were readmitted within 90 days of their index procedures. Thirty-one patients were readmitted for orthopaedic reasons (31/69; 45%) and 38 of 69 were readmitted for medical reasons (55%). Three readmissions (three of 69; 4%) were identified as potentially preventable. Of these potentially preventable readmissions, one was orthopaedic (hip dislocation) and two were medical. Thirty-day readmissions were more likely to be orthopaedic than 90-day readmissions (odds ratio, 4.06; 95% CI, 1.18-13.96; p = 0.026).

CONCLUSIONS

Using a panel of expert reviewers, available existing criteria, and consensus methodology, it appears only a small percentage of readmissions after THA are potentially preventable. Orthopaedic readmissions occur earlier during the postoperative course. Currently, existing policies and readmission penalties may not serve as valuable external quality metrics. The readmission rates in our study may represent the threshold for expected readmission rates after THA. Future studies should enroll larger numbers of patients and have independent review panels in efforts to refine criteria for what constitutes preventable readmissions.

LEVEL OF EVIDENCE

Level III, therapeutic study.