title: Gliding resistance versus work of flexion--two methods to assess flexor tendon repair.
abstract: Two methods for measuring the ability of the flexor tendon to glide following repair are commonly cited in the literature; gliding resistance (GR) at the tendon-pulley interface and work of flexion. The GR measures the friction force at the tendon-pulley interface, while the work of flexion characterizes whole finger function during flexion. Since a portion of the total work of flexion (TWOF), termed the internal work of flexion (IWOF), is expended due to the tendon-pulley interaction, a relationship between the work of flexion and GR should be present. The purpose of this study was to quantify this correlation. Forty-eight flexor digitorum profundus tendons in 48 mongrel dogs were transected and repaired with a modified Kessler technique and an epitenon running suture. Post-operatively, the operated paw was immobilized in a cast. Dogs were sacrificed at 1, 3, 5 or 7 days after surgery. In each repaired digit work of flexion and GR were measured. While the GR was not significantly different over the time points, the TWOF decreased at 5 days after surgery and then increased at 7 days (p<0.05). There was little correlation between TWOF and GR (r=0.25, p=0.07). However, there was a strong correlation between IWOF and GR (r=0.76, p<0.05) suggesting that measurement of GR could be used as a predictor of IWOF within the short term after tendon repair.
authors.affiliation: Biomechanics Laboratory, Department of Orthopedics, Division of Hand Surgery, Mayo Clinic/Mayo Foundation, 200 First Street SW-14A, Rochester, MN 55905, USA. pamadio@mayo.edu
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Tanaka
authors.forename: Peter C
authors.initials: PC
authors.lastname: Amadio
authors.forename: Chunfeng
authors.initials: C
authors.lastname: Zhao
authors.forename: Mark E
authors.initials: ME
authors.lastname: Zobitz
authors.forename: Kai-Nan
authors.initials: KN
authors.lastname: An
mesh_terms: D000818:Animals; D004285:Dogs; D005552:Forelimb; D009043:Motor Activity; D013708:Tendon Injuries; D013710:Tendons / Q000503:physiopathology* / Q000601:surgery; D014945:Wound Healing; D014950:Wounds, Penetrating / Q000503:physiopathology* / Q000601:surgery