Shoulder arthroplasty device clearance: an ancestral network analysis

BACKGROUND

The US Food and Drug Administration (FDA) oversees medical device regulation and oversight in the United States, and the majority of shoulder arthroplasty devices are cleared via the 510(k) pathway, in which a device demonstrates "substantial equivalence" to a previously cleared predicate. The purpose of this study was to determine an interconnected ancestral network of shoulder arthroplasty devices and determine equivalency ties to devices subsequently recalled by the FDA for design-related issues.

METHODS

The FDA 510(k) database was used to identify all legally marketed shoulder arthroplasty devices from May 28, 1976, to July 1, 2021. Direct predicate information obtained via clearance summary documents associated with each device was used to generate an ancestral genealogy network for all shoulder arthroplasty devices cleared between July 1, 2020, and July 1, 2021. FDA design recalls were analyzed, and the number of descendant devices was calculated for each recalled device.

RESULTS

An evaluation of all 476 510(k) premarket notification pathway-cleared shoulder devices since 1976 identified 0-313 descendant devices for each. Eighty of these devices (16.8%) have since been recalled, of which 10 recalls were directly related to implant design issues. Furthermore, among 29 of the most recently cleared devices (July 1, 2020-July 1, 2021), 16 (55.2%) claim predicates devices that have subsequently been withdrawn from the market because of design-related failures.

CONCLUSIONS

Shoulder arthroplasty devices are linked together via an interconnected FDA 510(k) equivalency approval network dating back to 1976 despite substantive changes in material specifications and device design, many of which have since been recalled. Many of the cleared modern devices claim predicates based on subsequently recalled prostheses.

Biomechanical analysis of anterior stability after 15% glenoid bone loss: comparison of Bankart repair, dynamic anterior stabilization, dynamic anterior stabilization with Bankart repair, and Latarjet

BACKGROUND

Dynamic anterior shoulder stabilization (DAS) with Bankart repair is a recently described stabilization technique thought to be more robust than an isolated Bankart repair while avoiding many coracoid transfer-related complications and technical demands. DAS involves transfer of the long head biceps through a subscapularis split to the anterior glenoid to create a sling effect. We hypothesize that DAS with Bankart repair will restore anterior stability in a human-cadaveric model with subcritical (15%) glenoid bone loss.

METHODS

Eight cadaveric shoulders were tested using an established shoulder simulator to record glenohumeral translations with an accuracy of ±0.2 mm. Shoulders were tested in 5 states-intact soft tissues, Bankart defect with 15% bone loss, isolated Bankart repair, DAS with Bankart repair, isolated DAS, and Latarjet. A 45 N anterior force was applied through the pectoralis major tendon, and translation of the humeral head was recorded and compared with repeated measures analysis of variance.

RESULTS

The anterior translation in the intact (native) glenoid was 4.7 mm at neutral position and 4.6 mm at 45° external rotation. Anterior translation significantly increased after introducing a Bankart defect with 15% glenoid bone loss to 9.1 mm (neutral, P = .002) and 9.5 mm (45° external rotation, P < .001). All repair conditions showed a significant decrease in anterior translation relative to Bankart defect. DAS with Bankart repair decreased anterior translation compared with the Bankart defect: 2.7 mm (neutral, P < .001) and 2.1 mm (45° external rotation, P < .001). DAS with Bankart repair significantly decreased anterior translation compared with the isolated Bankart repair (2.7 mm vs. 4.7 mm, P = .023) and the isolated DAS (2.7 mm vs. 4.3 mm, P = .041) in neutral position. The Latarjet procedure resulted in the greatest reduction in anterior translation compared with the Bankart defect: 1.2 mm (neutral, P < .001) and 1.9 mm (45° external rotation, P < .001).

CONCLUSIONS

DAS with Bankart repair is a viable alternative to restore anterior glenohumeral stability with a 15% glenoid defect at a greater degree than either DAS or Bankart repair alone. The Latarjet procedure was the most effective in reducing anterior translation but restrained the anterior translation significantly more than the native glenoid.

Evaluation of Feedback Systems for the Third-Year Surgical Clerkship

OBJECTIVE

To compare faculty-to-student feedback rates from 2 different data sets: direct observation cards (direct evidence) and end-of-clerkship questionnaires (ECQs, secondary student reporting). We as authors hypothesized that direct evidence from observation cards would yield higher rates of feedback, compared with student-reported ECQs.

DESIGN

Data were gathered from 2 consecutive medical classes of the third-year surgical clerkship. Data were analyzed retrospectively. Subjects and authors were blinded during data collection and analysis.

SETTING

University of Michigan Medical School (UMMS) and University of Michigan Health System (UMHS). UMHS is an academic tertiary care center, located in Ann Arbor, Michigan.

PARTICIPANTS

Data were gathered from all third-year medical students completing the surgical clerkship from 2012 to 2014. Data were available for 309 students, compared to 313 students who graduated from UMMS during that time.

RESULTS

Directly measured rates of feedback showed higher rates of midclerkship feedback (95.43% vs 83.57%, p < 0.05), feedback on an observed history-taking (97.62% vs 84.87%, p < 0.05), and feedback on an observed physical examination (99.67% vs 79.71%, p < 0.05), when compared with the ECQ.

CONCLUSION

These data suggest that solely using ECQs to assess feedback rates may be inadequate. The use of multiple methods to assess feedback may therefore be a prudent choice for surgical clerkships.