American Society for Peripheral Nerve

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The Semilunar Pulley Orthosis (SPOrt) Decreases Flexor Tendon-Phalanx Distance In Climbers With Chronic A2 Pulley Ruptures
Kate D. Bellevue, MD1; Christopher H. Allan, MD2; Nelson Hager, MS, MD3; Winston J. Warme, MD1
1University of Washington Medical Center, Seattle, WA, 2Department of Orthopaedics and Sports Medicine, University of Washington, Seattle, WA, 3F. Edward Hebert Uniformed Services University of the Health Sciences, Bethesda, MD

The Semilunar Pulley Orthosis (SPOrt) decreases flexor tendon-phalanx distance in climbers with chronic A2 pulley ruptures

A2 pulley ruptures are one of the most common injuries sustained by climbers. One study of competitive climbers found 26% of climbers had at least one pulley rupture. Ruptures lead to increases in the flexor tendon-phalanx distance (TPD) and limit active joint flexion. Interventions to date, such as taping, have been limited in their ability to adequately support the tendon sheath. We hypothesized the more rigid Semilunar Pulley Orthosis (SPOrt), would significantly reduce the flexor TPD in climbers with A2 pulley ruptures (Fig 1a).
Materials & Methods
A prospective case series of climbers with chronic A2 pulley injuries was studied. Climbers were screened with an ultrasound and those with TPD greater than 2 mm (Grade III or IV injuries) were included in the study. TPD was measured with and without the SPOrt (modified with a cut out for ultrasound, Fig 1b) in both the stressed and relaxed positions (Fig 2). The contralateral uninjured finger served as a control.
Forty-seven fingers were scanned and 15 were diagnosed with a complete A2 pulley rupture. 53% of injuries involved the middle finger, 40% involved the ring finger, and 7% involved the index finger. Average TPD in the stressed position was 3.020.67 mm without the SPOrt and 2.250.45 mm with the SPOrt applied, (p<0.0001). Average decrease in TPD was 0.780.45 mm for a 26% reduction in TPD in the stressed condition and 17% reduction at rest. With stress, the TPD was 1.66 times the TPD of the contralateral digit, which decreased to 1.23 times the TPD with the SPOrt applied (64% closer to the TPD of the control digit).
SPOrt application is a highly effective method to reduce TPD in climbers with chronic A2 pulley injuries, (p<0.0001), better than the most effective taping technique. The SPOrt is better able to decrease TPD in a stressed position than at rest, indicating that the efficacy of the SPOrt increases with activities that stress the flexor tendon sheath, such as climbing or manual labor. The SPOrt has the potential to protect injured or reconstructed pulleys as patients return to physical work or sport.
Figure 1: A) SPOrt in place. B) SPOrt modified with cut out.

Figure 2: Ultrasound images in the stressed condition A) without and B) with the SPOrt.

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