Intrasynovial Tendon Graft for Chronic Flexor Tendon Laceration of the Finger: A Case Report
The patient was a 25-year-old, right-handed man presenting with limited flexion of his right ring finger. He had sustained a knife injury at the base of the right ring finger. He visited a surgeon at a local clinic, who sutured the wound; the patient was then informed that the flexor tendon was intact. However, since the limited flexion persisted even 4 months after the injury, he was referred to our hospital. On examination, the active ROM of the right ring finger was found to be 88°, 68°, and 12° of flexion and 0°, 10°, and 0° of extension for the metacarpophalangeal (MP) joint, proximal interphalangeal (PIP) joint, and distal interphalangeal (DIP) joint, respectively. The total active motion (TAM) was 168° (percent TAM, 62%) (Fig. ). Grip strength was 24 kg for the right hand and 41 kg for the left hand. The disabilities of the arm, shoulder, and hand (DASH) score was 31 points.\nThe patient was diagnosed with flexor digitorum profundus (FDP) tendon laceration at the A2 pulley level. Flexor tendon reconstruction from the palm to the fingertip was then performed using the left second-toe flexor tendon as a graft at 5.5 months after the injury, under general anesthesia. The left side was chosen because his right foot was dominant. Through a volar zigzag skin incision, the involved flexor system was exposed from the A2 to the A5 pulleys. All pulleys were intact. Frayed and degenerated distal stump and enlargement of the swollen proximal stump of the FDP tendon were noted (Fig. ). The flexor digitorum superficialis (FDS) tendon was found to have been transected and attached to the PIP joint volar plate. A separate skin incision was made over the A1 pulley to locate the proximal stump of the FDP tendon.\nThe left second-toe flexor tendon was harvested by the method described by Leversedge et al. []. Thereafter, the grafted tendon was advanced distally through a series of fibrous pulleys in the ring finger. Since the graft was not easily maneuvered through the A2 pulley with the FDS tendon attached to the volar plate, the FDS tendon was cut. The size and shape of the graft tendon were suitable for the ring finger synovial space. A distal juncture was created by a modification of the classic Bunnell tendon-to-bone pull-out technique. For the proximal juncture, 3 weaves of the grafted tendon were applied to the proximal stump of the FDP tendon (Fig. ).\nOn postoperative day 1, modified Kleinert’s early motion was initiated with a dorsal extension block splint, and active flexion was initiated 3 weeks after surgery. At 7 months after surgery, the TAM was 194° (percent TAM: 71%). Magnetic resonance imaging (MRI) of the ring finger revealed that the configuration of the grafted tendon was almost normal (Fig. ). Since the patient wished to gain further active flexion of the right ring finger, tenolysis was performed 7 months after surgery. The appearance of the graft tendon from the second toe was normal, without apparent degenerative findings (Fig. ). Adhesion was observed from the palm to the insertion point at the base of the distal phalanx, especially, at the proximal juncture site in the extrasynovial area. Release of the grafted tendon from the surrounding structures was easily accomplished. Immediate active ROM exercises were encouraged. At 1.5 years after tenolysis, the active ROM was 90° of flexion and 12° of extension for the MP joint, 100° of flexion and 16° of extension for the PIP joint, and 80° of flexion and -2° of extension for the DIP joint. TAM was 268° (percent TAM: 99%) (Fig. ). Grip strength was 46 kg for the right hand. The DASH score was 5.8 points. Although limited flexion of the second toe was evident, the patient’s gait was normal and he experienced no further morbidity at the donor site.