What are the Minimum Clinically Important Difference Values for the PROMIS and QuickDASH After Carpal Tunnel Release? A Prospective Cohort Study.

BACKGROUND: To better define the clinical significance of patient-reported outcomes, the concept of a minimum clinically important difference (MCID) exists. The MCID is the minimum change that a patient will perceive as meaningful. Prior attempts to determine the MCID after carpal tunnel release are limited by methodologic concerns, including the lack of a true anchor-based MCID calculation. QUESTIONS/PURPOSES: To address previous methodologic concerns in existing studies, as well as establish a clinically useful value for clinicians, we asked: What are the MCID values for the Patient-Reported Outcomes Measurement Information System (PROMIS) Upper Extremity (UE), PROMIS Pain Interference (PI), and the QuickDASH after carpal tunnel release? METHODS: We conducted a prospective cohort study at an urban, Midwest, multihospital, academic health system. One hundred forty-seven adult patients undergoing unilateral carpal tunnel release between September 2020 and February 2022 were identified. PROMIS UE, PI, and QuickDASH scores were collected preoperatively and 3 months postoperatively. We also collected responses to an anchor-based question: "Since your treatment, how would you rate your overall function?" (much worse, worse, slightly worse, no change, slightly improved, improved, or much improved). Patients who did not respond to the 3-month postoperative surveys were excluded. A total of 122 patients were included in the final analysis (83% response proportion [122 of 147]). The mean age was 57 years (range 23 to 87 years), and 68% were women. The MCID was calculated using both anchor-based and distribution-based methods. Although anchor-based calculations are generally considered more clinically relevant because they consider patients' perceptions of improvement, an estimation of the minimum detectable change (which represents measurement error) relies on a distribution-based calculation. We determined a range of MCID values to propose a final MCID value for all three instruments. A negative MCID value for the PROMIS PI instrument represents a decrease in pain, whereas a positive value for the PROMIS UE instrument represents an improvement in function. A negative value for the QuickDASH instrument represents an increase in function. RESULTS: The final proposed MCID values were 6.2 (interquartile range [IQR] 5.4 to 9.0) for the PROMIS UE, -7.8 (IQR -6.1 to -8.5) for the PROMIS PI, and -18.2 (IQR -13.3 to -34.1) for the QuickDASH. CONCLUSION: We recommend that clinicians use the following values as the MCID after carpal tunnel release: 6 for the UE, -8 for the PI, and -18 for the QuickDASH. Surgeons may find these values useful when counseling patients postoperatively regarding improvement. Future studies could examine whether a single MCID (or small range) for PROMIS instruments is applicable to a variety of conditions and interventions. LEVEL OF EVIDENCE: Level II, therapeutic study.

Entrapment of the index finger radial collateral ligament in the metacarpophalangeal joint: A case report.

Introduction: Digital collateral ligament injuries are common hand injuries that can cause significant pain and functional impairment. Ultrasonography can be useful in the evaluation of these ligamentous injuries, as it is both cost-effective and allows for easy, dynamic evaluation during imaging. Case report: We report a rare sonographic finding of an index finger radial collateral ligament injury that was found to have a flap of the ligament entrapped within the metacarpophalangeal joint, which to our knowledge has not been described previously. We correlate this finding with an intraoperative image of the entrapment of the collateral ligament. We also report on the novel application of superb microvascular imaging to aid in the diagnosis of digital collateral ligament injury. Discussion: This particular injury pattern has not been reported in the literature previously and likely explains the patient's lack of improvement with nonoperative management. Our finding is similar to a Stener lesion seen in a thumb ulnar collateral ligament injury in which the ligament is unable to heal due to entrapment. In addition, using superb microvascular imaging (SMI), we were able to visualize hyperemia to surrounding structures and the ligament itself which suggested an acute injury. Conclusion: We anticipate that this case report will provide sonographers with knowledge and images of this specific injury pattern to the digital collateral ligaments.

Inhibition of platelet-derived growth factor signaling prevents muscle fiber growth during skeletal muscle hypertrophy.

The platelet-derived growth factor receptors alpha and beta (PDGFRα and PDGFRß) mark fibroadipogenic progenitor cells/fibroblasts and pericytes in skeletal muscle, respectively. While the role that these cells play in muscle growth and development has been evaluated, it was not known whether the PDGF receptors activate signaling pathways that control transcriptional and functional changes during skeletal muscle hypertrophy. To evaluate this, we inhibited PDGFR signaling in mice subjected to a synergist ablation muscle growth procedure, and performed analyses 3 and 10 days after induction of hypertrophy. The results from this study indicate that PDGF signaling is required for fiber hypertrophy, extracellular matrix production, and angiogenesis that occur during muscle growth.

Simvastatin reduces fibrosis and protects against muscle weakness after massive rotator cuff tear.

BACKGROUND: Chronic rotator cuff tears are a common source of shoulder pain and disability, and patients with chronic cuff tears often have substantial weakness, fibrosis, inflammation, and fat accumulation. Identifying therapies to prevent the development of these pathologic processes will likely have a positive impact on clinical outcomes. Simvastatin is a drug with demonstrated anti-inflammatory and antifibrotic effects in many tissues but had not previously been studied in the context of rotator cuff tears. We hypothesized that after the induction of a massive supraspinatus tear, simvastatin would protect muscles from a loss of force production and fibrosis. METHODS: We measured changes in muscle fiber contractility, histology, and biochemical markers of fibrosis and fatty infiltration in rats that received a full-thickness supraspinatus tear and were treated with either carrier alone or simvastatin. RESULTS: Compared with vehicle-treated controls, simvastatin did not have an appreciable effect on muscle fiber size, but treatment did increase muscle fiber specific force by 20%. Simvastatin also reduced collagen accumulation by 50% but did not affect triglyceride content of muscles. Several favorable changes in the expression of genes and other markers of inflammation, fibrosis, and regeneration were also observed. CONCLUSIONS: Simvastatin partially protected muscles from the weakness that occurs as a result of chronic rotator cuff tear. Fibrosis was also markedly reduced in simvastatin-treated animals. Whereas further studies are necessary, statin medication could potentially help improve outcomes for patients with rotator cuff tears.

Aging-associated exacerbation in fatty degeneration and infiltration after rotator cuff tear.

BACKGROUND: Rotator cuff tears are one of the most common musculoskeletal complaints and a substantial source of morbidity in elderly patients. Chronic cuff tears are associated with muscle atrophy and an infiltration of fat to the area, a condition known as "fatty degeneration." To improve the treatment of cuff tears in elderly patients, a greater understanding of the changes in the contractile properties of muscle fibers and the molecular regulation of fatty degeneration is essential. METHODS: Using a full-thickness, massive supraspinatus and infraspinatus tear model in elderly rats, we measured fiber contractility and determined changes in fiber type distribution that develop 30 days after tear. We also measured the expression of messenger RNA and micro-RNA transcripts involved in muscle atrophy, lipid accumulation, and matrix synthesis. We hypothesized that a decrease in specific force of muscle fibers, an accumulation of type IIb fibers, and an upregulation in atrophic, fibrogenic, and inflammatory gene expression would occur in torn cuff muscles. RESULTS: Thirty days after the tear, we observed a reduction in muscle fiber force and an induction of RNA molecules that regulate atrophy, fibrosis, lipid accumulation, inflammation, and macrophage recruitment. A marked accumulation of advanced glycation end products and a significant accretion of macrophages in areas of fat accumulation were observed. CONCLUSIONS: The extent of degenerative changes in old rats was greater than that observed in adults. In addition, we identified that the ectopic fat accumulation that occurs in chronic cuff tears does not occur by activation of canonical intramyocellular lipid storage and synthesis pathways.