A2 and A4 flexor pulley biomechanical analysis: comparison among gender and digit.

Rock climbing has become increasingly more popular in the USA over the past two decades. Accordingly, with increased participation comes an increase in climbing-related injuries. Rooks et al noted that three-quarters of elite and recreational climbers will suffer upper extremity injuries, approximately 60% involving the hand or wrist and 40% divided evenly between the shoulder and elbow. Most of these injures will be strains, microtrauma, and tendonitis; however, 30-50% represent trauma to the proximal interphalangeal region. The purpose of this study was to investigate the biomechanical properties of the A2 and A4 pulley and compare biomechanical properties among gender and digit. A specially designed materials testing machine, shown in the included figure, measured maximum breaking load, displacement and stiffness of the A2 and A4 pulleys of ten cadaveric hands using an S hook to apply a steady force until complete pulley rupture. The A2 and A4 biomechanical properties of breaking load, displacement, and stiffness did not significantly differ among the index, middle, ring, and little fingers. Additionally, there was no significant difference in A2 or A4 pulley biomechanics between male and female specimens. The A2 and A4 pulleys among differing digits and genders have similar biomechanical properties in regards to maximum breaking load, displacement, and stiffness.

Minimally invasive A2 flexor tendon pulley and biomechanical comparison with two accepted techniques.

The increasing popularity of rock climbing and its associated injury of closed traumatic pulley A2 rupture has sparked investigator interest in pulley biomechanics. Biomechanically, the A2 and A4 pulleys are important for preventing bowstringing of the flexor tendon upon digital flexion. The literature is replete with reparative techniques for A2 pulley rupture. These techniques include direct fibrous tissue repair, as well as the use of palmaris longus autograft for single- and double-loop reconstruction. Through a previously undescribed minimally invasive double-anchor technique, we used palmaris longus tendon and 2-mm bioabsorbable suture anchors to reconstruct the A2 pulley at its anatomical location in a cadaver model. Then the ultimate load to failure of this reconstruction was tested against 2 known reconstructive techniques, namely, single-loop and double-loop palmaris repair. There was no significant difference between the strength of the previously described single-loop technique and our novel double-anchor technique. Furthermore, our minimally invasive repair obviated the need for the circumferential dissection and soft tissue trauma associated with the single- and double-loop repairs.

Experience with transtrapezium approach for transverse carpal ligament release in patients with coexisted trapeziometacarpal joint osteoarthritis and carpal tunnel syndrome.

An experience with transtrapezium approach for carpal tunnel release is reported. This technique seems to be successful in cases when carpal tunnel syndrome and first carpometacarpal joint osteoarthritis coexist and surgical treatment is indicated for both conditions. The transtrapezium approach to carpal tunnel release allows for complete carpal tunnel release without increasing the risk of surgical complications.