Disruption of the Finger Flexor Pulley System in Elite Rock Climbers

Abstract

We treated 13 elite rock climbers for isolated disruptions of the pulleys of the long fingers. Diagnosis and treatment were based on the clinical finding of bow-stringing, which was confirmed by magnetic resonance imaging. Eight patients had bowstringing indicating incomplete disruption of the major pulley A2 and were treated nonoperatively (group A). Five patients showed bowstringing indicating complete disruption of the pulley A2. After failed nonoperative treatment, the pulleys were reconstructed (group B). The mechanism of injury and clinical and subjective results were evaluated. At a 31-month follow-up (range, 18 to 43 months), loss of extension in the proximal interphalangeal joint measured 5.6 degrees (range, 0 degree to 10 degrees) in group A and 4 degrees (range, 0 degree to 10 degrees) in group B. Circumference of the finger section was increased 4.2 mm in group A (range, 0 to 10 mm) and 4.8 mm in group B (range, 0 to 10 mm). Grip strength decreased 20 N in group A (range, 10 to 50 N) and 12 N in group B (range, 10 to 30 N). Four patients in group A and one in group B had bowstringing at clinical evaluation. On follow-up magnetic resonance images, bowstringing remained unchanged in group A but was reduced in all patients in group B. Good subjective results were seen in both groups.

Friction between human finger flexor tendons and pulleys at high loads

“…During rock climbing, the A2 pulley and the A4 pulley are stressed in a way that injuries and overuse are very common (Bollen, 1990;Cartier et al, 1985;Gabl et al, 1998;Tropet et al, 1990). Foremost the so-called crimp grip position where the PIP joint is flexed 901 or more and the DIP joint is hyperextended results in a distinct bowstringing (Schweizer, 2001) and stresses the distal edge of the A2 pulley mostly.…”

“…The presence of friction would explain also why rock climbers can resist immense forces by the finger flexors during the grip of very small holds although they do not show proportionally greater concentric muscular force compared to non-climbing subjects (Watts et al, 1996). Furthermore, friction would explain the mechanism of injury to the A2 pulleys in rock climbers more exactly (Bollen, 1990;Gabl et al, 1998), (A2 pulley: annular like ligament, part of the flexor tendon sheath, at the volar side of the proximal phalanx, prevents flexor tendons from bowstringing). Until now there is only evidence that friction between flexor tendons and pulleys may be apparent in a few in vitro measurements (Uchiyama et al, , 1997.…”

Diagnosis of finger flexor pulley injury in rock climbers: A systematic review

“…Two papers were studies of diagnostic accuracy (18,19). The remainder of the articles included seven reviews (10,13,(15)(16)(17)24,34), two case studies (8,9), eight comparative studies (12,14,22,23,27,28,30,31), and 10 noncomparative studies (2,3,11,20,21,25,26,29,32,33), of varying quality. The findings are presented below in three sections corresponding to the three research questions.…”

Evaluation of finger A3 pulley rupture in the crimp grip position—a magnetic resonance imaging cadaver study

“…The prevalence of closed flexor tendon pulley rupture in rock climbers, as first described by Bollen [31] and Tropet [32] in the 1980s, is still growing with the higher popularity of sport climbing and is today a frequently encountered injury in sport climbing and non-climbing activities alike [1,4]. Recent studies have suggested conservative treatment for single pulley rupture without clinical bowstringing [1,33].…”

“…Closed flexor tendon annular (A) pulley ruptures are frequently encountered injuries in sport climbing, but can also occur in non-climbing activities of daily life [1][2][3][4]. The A2, A3 and A4 pulleys are most prone to injury and typically rupture in the middle and ring fingers [5] when subjected to high loads in the crimp grip position [6,7].…”