This 80-year-old man fell off of his tractor 6 months prior to examination, with a resultant chronic subluxation of his fifth digit due to radial sagittal band rupture.
This healthy 80-year-old man had ulnar deviation and inability to extend his fifth digit unless he relocated it to an extended position by using his other hand. He was pain free, but found this embarrassing and functionally awkward (▶Fig. 16.1).
The use of relative motion extension splinting for sagittal band rupture was first described in 2001 and in a series of patients successfully treated for acute sagittal band rupture in 2005. Although there are several proposed operations for chronic sagittal band rupture, all recommend immobilization postoperatively for 6 to 10 weeks. The morbidity is significantly greater with immobilization than with early active motion and function in a relative motion extension splint, placing the repaired digit in 15 to 20 degrees relatively greater MP extension than adjacent digits. Although this would likely work for any of the techniques utilized for chronic sagittal band rupture, we prefer local anesthesia with epinephrine to verify successful correction and to confirm the value of the splint to maintain correction, and we create a tendon graft pulley to avoid relying on the questionable strength of a repaired or reconstructed sagittal band. The validity of the splint protection of repair is demonstrated in a video with only a single 6–0 nylon suture placed initially to test the result without and then with a ribbon retractor relative motion extensor splint.
Creating a tendon graft pulley attached through bone in the head of the metacarpal successfully centralizes the long extensor tendon and relative motion extension splinting preserves motion without adherence or rupture. Tendon grafts have been used successfully for this purpose from the extensor indicis proprius, juncturae tendinum, extensor retinaculum, palmaris longus, and one half of the flexor carpi radialis. The author has preferred the latter two as seeming the easiest, especially the palmaris longus, when available. Burr holes are made through the dorsal cortical surface of the metacarpal head, and the tendon graft passed through bone, surrounding the extensor tendon in a centralized position and secured with a Pulvertaft weave of the tendon graft and 4–0 Prolene suture. The suture line is then rotated so it is then within the bone. A few days after surgery, the patient is placed in a relative motion extension splint and active hand use is encouraged. A video illustrates the technique, done under local anesthesia, using only an initial 6–0 nylon suture to illustrate force on the graft, without and with a ribbon retractor relative motion extensor splint.
We have successfully used nonsurgical relative motion extensor splinting as late as 6 weeks after closed sagittal band rupture if the patient is still inflamed and symptomatic while collagen remodeling is still possible, recovering lost motion and becoming pain free in the splint. The patient is splinted full time for 6 weeks and encouraged to functionally use their hand. However, when the patient develops chronic subluxations without pain or swelling, a surgical solution is necessary.