Assessment of Thumb Positioning in the Treatment of Ulnar Collateral Ligament Injuries

Abstract

In the treatment of ulnar collateral ligament injuries in the metacarpophalangeal joint of the thumb, a cast or splint is often molded with the thumb and hand positioned so the patient can return quickly to a particular sport or activity. However, it is unknown whether a given position of immobilization or whether an early rehabilitation program will compromise ligament healing by causing undue tension in the ligament. To better define acceptable positions for thumb immobilization and a safe range of motion, this laboratory study measured strain in the ulnar collateral ligament at different degrees of metacarpophalangeal joint flexion. Ligament strain was found to increase with increasing joint flexion; the most significant increases in strain occurred as the joint moved from 0 degree to 25 degrees of flexion, with the dorsal portion of the ligament demonstrating greater strain than the palmar portion. Based on these results, immobilization of the metacarpophalangeal joint in excessive flexion and unrestricted early rehabilitation exercises should be done with caution and guided by the grade of injury or the quality of repair.

A biomechanical modeling of injury, repair, and rehabilitation of ulnar collateral ligament injuries of the thumb

“…The strain results of this study compare well with those reported by Adams et al 16 and Firoozbakhsh et al 17 This study went one step further in that we were able to test the strain in the ligament during rupture and then again after subsequent suture anchor repair of the ruptured ligament complex. Although some differences were noted in the strains with active motion before and after ligament repair, the strains recorded at specific flexion angles were not statistically different before and after ligament repair.…”

“…16 The midpoint of the proper collateral ligament insertion was selected for distal marker placement. The specimen then was mounted into a custom-made fenestrated vice apparatus that allowed reproducible positioning of the specimen during testing as well as application of physiologic forces in line with the flexor and extensor tendons ( Fig.…”

“…6,7 Only preliminary biomechanical data, however, have been presented that suggest that suture anchor repair of the UCL is able to withstand the stresses of these early motion protocols. 16,17 We hypothesize that the technique of suture anchor repair of the UCL is strong enough to withstand an early active motion therapy protocol. To test this hypothesis we first sought the creation of an accurate in vitro model of a complete rupture of the UCL of the thumb.…”

Impact of Joint Position and Joint Morphology on Assessment of Thumb Metacarpophalangeal Joint Radial Collateral Ligament Integrity

“…5 The distance between the pins was measured with a digital micrometer with the MCP joint at maximum extension and at 0 , 15 , 30 , 45 , and maximum flexion for each specimen. This measurement was taken 3 separate times by the same researcher and averaged for each MCP joint position.…”

Sprains of the Metacarpophalangeal Joint of the Thumb

“…A global winding dynamic orthosis of the thumb or an analytical dynamic orthosis of the metacarpophalangeal can be made after 8 weeks if there's a persisting stiffness [ 11 ].…”