Abstract
Introduction: Flexor tendon repair in zone 2 has a high re-rupture rate. Various pulleyplasties were described to reduce gliding resistance. In an experimental study on pig trotters, we performed pulleyplasty by meshing alike split skin graft and determined its effect on breaking strength and gliding resistance of repaired tendon.
Method: Phase 1: Two pairs of middle pulley of the same pig were pulled apart from bone on Universal testing machine. One of each pair were meshed (10 rows of 1mm slits 2 mms apart longitudinally).
Phase 2: The two ends of two repaired flexor tendons were attached to a tension load cell each. The proximal end load cell was connected to Universal testing machine. Gliding resistance was measured under saline before and after meshing.
Phase 3: The test was repeated on 4 specimens using a digital load scale. Ten observations of peak resistance were obtained each with normal pulley, meshed pulley, after edge tying of the pulley.
Results: Breaking strengths were 162 and 59 N in one pair and 89 and 50 N in another. The pulleys became 1.5 – 4 times stretchable.
Meshing increased the gliding resistance by approximately 20% and 30% in phase 2 and 3 respectively. Edge tying decreased the gliding resistance by 27% below that of normal pulley
Discussion and Conclusion: Meshing weakens significantly but breaking strength stayed above 50 N, which is more than average breaking strength of a tendon repair (30N, Norris et al). Meshed pulley were dragged farther and preventing it by edge tying decreased the gliding resistance.
No animal was killed for the study.
Correspondence should be addressed to Ms Larissa Welti, Scientific Secretary, EFORT Central Office, Technoparkstrasse 1, CH-8005 Zürich, Switzerland
