Remodeling of the gliding surface after flexor tendon repair in a canine model in vivo

Abstract

Maintaining a smooth lubricated surface between the flexor tendon and sheath after tendon repair is very important for restoration of digit function. We studied the tendon surface after tendon repair mechanically in a canine model in vivo by measuring frictional force. One hundred and twenty flexor digitorum profundus (FDP) tendons were lacerated to 80% of their cross-section and repaired with either a modified Kessler (MK) or Becker (MGH) repair. The postoperative therapeutic regimen was either synergistic wrist and digit motion (SWM) or passive digit flexion and extension with the wrist fixed in 45" of flexion (FIX). The dogs were sacrificed at one, three, or six weeks postoperatively. Thirty six F D P tendons from normal paws served as the control group, with each control tendon tested in two different conditions: intact and immediately after partial laceration and repair (0 time), making a total of five different timing points (intact, 0 time, one week, three weeks, and six weeks) for each repair type and each postoperative therapy. Frictional force between tendon and proximal pulley was evaluatcd after breaking any adhesions. Compared to intact tendons, friction was significantly increased immediately after tendon repair. The friction of the M K repair was significantly less than that of the M G H repair at all time and therapy groups, except at six weeks in the SWM group. For the M G H repair. at six weeks friction in the SWM group was significantly less than friction in the FIX group. This study showed that postoperative tendon gliding depends on the method of tendon repair and the postoperative therapy regimen. Furthermore, we have demonstrated that the gliding surface after tendon repair remodels with time.

Gliding resistance of the extensor pollicis brevis tendon and abductor pollicis longus tendon within the first dorsal compartment in fixed wrist positions

“…While the values for gliding resistance in the neutral position, roughly 0.2 N, are similar to those seen in other normal intrasynovial tendons [24,39], the values for gliding resistance in the most adverse wrist positions approach those seen in healing, lacerated tendons [39]. We believe it is reasonable to suspect that tendons with such high gliding resistance, such as the extensor pollicis brevis tendon with septation, might be vulnerable to develop de Quervain's disease.…”

Determination of frictional conditions between electrode array and endosteum lining for use in cochlear implant models

“…Although a similar range of friction coefficients have been reported for experiments involving tendon/pulley interface (0.07) (Uchiyama et al, 1995;Moro-oka et al, 1999;Zhao et al, 2002;Schweizer et al, 2003), articular cartilage (0.01-0.12 when sliding speed was about zero) (Wang and Ateshian, 1997;Krishnan et al, 2004) and pleural tissues (0.075) (D'Angelo, 1975;D'Angelo et al, 2004), it is difficult to directly compare these results with the range of friction coefficients that have been found for EA sliding over endosteum lining (0.04-0.19) since the materials and conditions used were quite different.…”

“…Therefore, the predictive capability of models is often limited by the accuracy of frictional conditions assumed in the model. A number of researchers have experimentally studied frictional behaviour of biological tissues in contacting with each other such as salivary secretions (Gans et al, 1990), limb/prosthetic socket (Zhang et al, 1996), tendon/pulley (Uchiyama et al, 1995;Moro-oka et al, 1999;Zhao et al, 2002;Schweizer et al, 2003), articular cartilage (Wang and Ateshian, 1997;Krishnan et al, 2004) and pleural tissues (D'Angelo, 1975;D'Angelo et al, 2004). A number of different methods have been used to determine frictional conditions in artificial joints (Unsworth, 1995), ceramic/ceramic contact (Zhou et al, 1997) and tribological properties of polymerized-graft material rubbed against an alumina ceramic with water lubrication (Ikeuchi et al, 1993).…”

Gliding characteristics and gap formation for locking and grasping tendon repairs: a biomechanical study in a human cadaver model

“…The simplified in vitro testing model is appropriate, especially a model such as the one we use that has been rigorously validated compared with more complex in vitro models as well as in vivo. 52,56 Third, tendon stretching will still occur between the transducer fixation pins in our gap measurement using DVRT. However, we tried to minimize this limitation by keeping a small gauge length (within 5 mm).…”