The Gliding Force and Work of Flexion in the Early Days after Primary Repair of Lacerated Flexor Tendons: an Experimental Study

Abstract

We measured the resistance to tendon mobilisation within the first 5 days after primary repair of digital flexor tendons of chickens. Forty-six long toes of 23 chickens were assigned to six surgical groups and one unoperated control group. The tendons were partially lacerated and surgically repaired. The resistance to simulated active digital flexion was assessed in six operated groups at 0, 1, 2, 3, 4 and 5 days postoperatively. The force of tendon motion and work of flexion increased gradually from day 0 to day 5. The force and work at days 4 and 5 were significantly higher than those at days 0 and 1. No statistical difference was found in the resistance at days 0, 1, 2 and 3. Our results indicate that the gliding resistance gradually increases over the first 5 days after surgery and suggest that tendon motion may be started after the first 3 days, to avoid moving during this period of increased resistance with increased risk of tendon rupture.

Biomechanical Analysis of Knotless Flexor Tendon Repair Using Large-Diameter Unidirection Barbed Suture

“…This and other characteristics of the barbed suture may affect work of flexion, a variable that was not measured in this study. Work of flexion has been correlated with multiple factors, including suture size [34] and configuration, [35] whether the FDP is repaired or partially resected [36], how the flexor tendon sheath is managed [37,38], time from injury [39], and the presence of edema [40], or compressive dressings [40]. It is certainly possible that the large diameter of the barbed suture, as well as friction between the exposed barbs or locking loop of the suture and the synovial lining of the flexor tendon sheath could have important effects on work of flexion.…”

Clinical use of a combined grasping and locking core suture technique for flexor tendon repair in zone II

“…Experimentally, the force of flexor tendon motion and work of flexion increases gradually during the first few days after repair under normal circumstances (i.e. in clean cut lacerations with no excessive digital oedema) [10]. Simulated digital oedema in experimental animals will significantly increase the work of flexion.…”

Strength of Tendon Repair Decreases in the Presence of an Intact A2 Pulley: Biomechanical Study in a Chicken Model

“…The flexor tendons, location of the major annular pulleys, and relationship between the flexor tendons and these major pulleys in chicken toes are similar to those of human fingers; this model has been previously used for investigation of digital flexor tendon surgery. [7][8][9][10][11] This study was approved by our institution and we followed guidelines for animal experimentation. The 50 white Leghorn chickens, each weighing about 1.5 kg, were killed and both feet (100 in total) were harvested from the knee joint level after tendon division and repair.…”