Clinically Significant Outcome Scores in Orthopaedic Sports Medicine Shoulder and Knee Surgery Are Increasing in Prevalence but Often Reported Incorrectly.

PURPOSE: To study the prevalence and quality of application of minimal clinically important difference (MCID), substantial clinical benefit (SCB), patient-acceptable symptomatic state (PASS), and maximum outcome improvement (MOI), reported in the orthopaedic sports medicine knee and shoulder literature in recent years and to bring awareness of proper use of such metrics. METHODS: A literature review of all shoulder and knee articles published from the American Journal of Sports Medicine (AJSM), Journal of Shoulder and Elbow Surgery (JSES), and Arthroscopy from 2016 to 2020 was performed, specifically investigating whether MCID, SCB, PASS, or MOI were used or reported. Additionally, the way these metrics were reported and interpreted was recorded. RESULTS: Out of 5,039 studies, 889 shoulder and knee studies met the inclusion criteria. Overall, 16.7% reported either MCID, PASS, or SCB. MCID was the most reported across all 3 journals. MCID was reported 12.4% of the time throughout the 5 years. PASS was reported 3.2% and SCB 1.1% of the time over the 5 years. MOI was not reported by any of the journals during this period. There was a statistically significant increase in MCID reporting in 2 of the 3 journals over the 5-year course, Arthroscopy (P = .02) and AJSM (P = .05). There was no statistically significant increase in PASS or SCB reporting rates in all 3 journals. Only 39.1% of studies reported MCID correctly (i.e., defined as the number of individual patients meeting MCID/total patients in the study). CONCLUSIONS: This study shows an increasing trend in the use of clinically significant outcome metrics, such as MCID, for interpretation of patient-reported outcomes; however, these individual metrics are often not being used on the individual level and subsequently not reported accurately. We recommend determining whether the specific metric met the threshold per individual patient and then reporting those as a percentage of the sample population to achieve the full potential of these metrics and translate them accurately across various studies. CLINICAL RELEVANCE: As the usage of clinically significant outcome metrics rises, so does the need for accurate reporting. These findings will encourage future studies to follow a more standardized format.

Mechanical Effects of Lag Screw Retightening in a Simulated Hindfoot Arthrodesis Model.

BACKGROUND: Nonunion following hindfoot arthrodesis may be caused by failure to maintain compression at the arthrodesis site. The ability of lag screws, commonly used in arthrodesis, to maintain compression in hindfoot bones has not been well characterized. The aim of this work was to quantify the stress relaxation response of hindfoot bone with initial and repeated compression with a lag screw. METHODS: Ten sets of 25-mm-diameter bone cylinders were cut from the talus and calcaneus in fresh-thawed cadaveric feet. A load cell was compressed between cylinders with an 8.0-mm partially threaded cannulated lag screw simulating arthrodesis. For 7 sets, screws were tightened by 3 quarter-turns, rested for 3 minutes, retightened 1 quarter-turn, and rested for 30 minutes. Three sets served as controls in which screws were not retightened. RESULTS: Maximum compression after initial screw tightening and retightening averaged 275 and 337 N (P = .07), respectively. Compression 3 minutes after initial screw tightening and retightening averaged 199 and 278 N (P = .027), respectively. The compression recorded 3 minutes after screw retightening was an average of 40% higher than that recorded 3 minutes after initial tightening. The average compression 30 minutes after screw retightening was 255 N, a compression loss of 25% from the average maximum compression after retightening. Eighty percent of this compression loss happened in an average of 5.5 minutes. CONCLUSION: Hindfoot bones exhibit compression loss over time during simulated arthrodesis. Compression maintenance in bone is improved with screw retightening. Further work is needed to understand the mechanism of action and determine optimum time for recompression. CLINICAL RELEVANCE: Retightening lag screws before wound closure may improve compression at the arthrodesis site and thereby decrease the chance of nonunion. LEVEL OF EVIDENCE: N/A, laboratory experiment.