Injuries to zones I, II, and III
An early mobilization protocol is recommended. A well-motivated and reliable patient can initiate a Duran or Indianapolis protocol. Otherwise, the Kleinert protocol is applied, with rubber bands attached to hooks glued to fingernails.

Modified Kleinert protocol
In the modified Kleinert protocol, Pulleys are added at the level of the distal palm to obtain maximum DIP flexion. Rubber bands are removed at night. All patients are instructed to passively extend the PIP joint completely inside the splint to avoid flexion contractures.
• At surgery, a half (dorsal-blocking) cast is applied with the wrist at 20-30° of flexion, MCP joints at 70-80° of flexion, and IP joints straight.
• After 1 week, the cast is removed and a thermoplastic splint is applied with the joints at the same angles. All digits stay in splint. The index finger may be left free if only the ring or small finger tendon is involved. Dynamic traction is applied, with the distal palmar pulley on the involved finger. The patient begins active extension from the dorsal-blocking splint against rubber band traction. The patient performs passive PIP and DIP motion within the restraints of the dorsal-blocking splint 4 times a day.
• After 2 weeks, sutures are removed. On intermittent days, the IP joints are positioned straight, with a dorsal-blocking splint only if fixed flexion contractures are developing.
• After 4 weeks, the patient begins active composite flexion and active extension out of splint. Dorsal-blocking continues between exercises.
• After 5 weeks, the dorsal-blocking splint is discontinued. The patient may initiate blocking exercises and functional electrical stimulation (FES) as necessary.
• After 6 weeks, the patient begins gentle passive extension. A static extension splint is used for extrinsic flexor tightness if necessary.
• After 8 weeks, light strengthening exercises with a firm-but-squeezable foam ball (eg, Nerf ball), putty, or a hand helper are begun.
• After 12 weeks, the patient resumes normal activities.

Duran protocol
The Duran protocol is most frequently used and modified by hand therapists. If a flexion contracture develops, 2 options exist: initiation of the Kleinert technique or controlled passive extension of IP joints with the more proximal joints in the protected position of full flexion.
• At surgery, a half (dorsal-blocking) cast is applied with the wrist at 20-30° of flexion, the MCP joints at 70-80° of flexion, and the IP joints straight.
• At 1 week, the cast is removed and a dorsal splint is placed. The wrist is held in 20° of flexion, and the MCP joints are held in relaxed flexion. With the MCP and PIP flexed, the DIP is passively extended. Then, with the DIP and MCP flexed. The PIP is extended. Thus, FDP and FDS repairs diverge.
• After 4.5 weeks, the splint is removed and a wristband with rubber band traction is applied. While awake, the patient passively flexes all joints of the affected finger towards the palm and then actively extends the finger to the splint hood 15-25 times per hour.
• After 5.5 weeks, the patient begins active flexion with wristband removal.
• After 7.5 weeks, the patient begins resisted flexion.

Indianapolis protocol
The Indianapolis protocol is indicated for patients with 4-strand Tajima and horizontal mattress repair with an additional peripheral epitendinous suture. Patients should be motivated and understanding. Digits should have minimal or moderate edema and minimal wound complications.
Two splints are used, the traditional dorsal-blocking splint with the wrist at 20-30° of flexion, MCP joints in 50° of flexion, and IP joints in neutral and the Strickland tenodesis splint. It allows full wrist flexion and 30° dorsiflexion. Digits have full range of motion and MCP joints are restricted to 60° extension.
• For the first 1-3 weeks, the modified Duran protocol is used. The patient performs repetitions of flexion and extension to the PIP joint, DIP joint, and the whole finger 15 times per hour. Exercise is restrained by dorsal splint. Then, the Strickland hinged wrist splint is applied. The patient passively flexes digits while extending the wrist. The patient then gently contracts the digits in the palm and holds for 5 seconds.
• At 4 weeks, the patient exercises 25 times every 2 hours without any splint. A dorsal-blocking splint is worn between exercises until the sixth week. Digits are passively flexed while the wrist extends. Light muscle contraction is held for 5 seconds and the wrist drops into flexion, causing digit extension through tenodesis. The patient begins active flexion and extension of the digits and wrist. Simultaneous digit and wrist extension is not allowed.
• After 5-14 weeks, the IP joints are flexed while the MCP joints are extended, and then the IP is extended.
• After 6 weeks, blocking exercises commence if digital flexion is more than 3 cm from the DPFC. No blocking is applied to the small finger FDP.
• At 7 weeks, passive extension exercises are begun.
• After 8 weeks, progressive gradual strengthening is begun.
• After 14 weeks, activity is unrestricted.

Delayed mobilization in zone I-V injuries
Delayed mobilization in zone I-V injuries is Indicated for unreliable patients, those with poor quality flexor tendon (eg, those due to crush injuries or revascularization problems), children aged 10 years or younger, and patients with multiple anatomical structures involved other than flexor tendons.
• A dorsal-blocking splint is applied. The wrist is held at 30° flexion, the MCP joints are held at 50° flexion, and the IP joints are extended.
• At 3 weeks, active and passive motion exercises are performed within the restraints of the splint.
• After 4.5 weeks, active and motion exercises are performed outside of the splint. Protective splinting is continuous.
• After 6 weeks, the splint is discontinued and passive motion exercises are begun in extension.

Injury in zones IV-V
• At surgery, a half (dorsal-blocking) cast is applied with wrist at 30° of flexion, the MCP joints at 50° of flexion, and the IP joints at full extension.
• After 3-5 days, the cast is removed, and a dorsal-blocking splint is applied at the same angles. The splint may vary depending on which tendon is injured (wrist versus digital tendon). Passive range of motion is begun within splint restrains.
• At 3 weeks, active range of motion is begun within splint restraints. FES is initiated a few days after the initiation of active range of motion.
• After 4 weeks, active range of motion outside splint is begun.
• After 6 weeks, splint use is discontinued and passive extension is begun.

Flexor pollicis longus injury
• At surgery, a dorsal-blocking cast is applied with the wrist in 20° flexion, the MCP and IP joints in 15° flexion, and the carpometacarpal (CMC) joint in palmar abduction.
• The dynamic or static protocol used in injuries to zones I-V is used.

Excursion/differential gliding
Hook and fist positions produce more gliding of the FDP than of the FDS. In rooftop (angle) and straight fist positions, FDS excursion exceeds FDP. Greatest excursion for FDS is in straight fist position and greatest excursion for FDP is in full fist position. Maximum gliding between the FDP and the FDS is in hook position. Straight, fist, and hook positions provide maximum differential gliding for both flexors. Greatest muscle contraction is used for both in sustained fist making.

Michael Neumeister,
MD, FRCSC, FACS,
Program Director, Assistant Professor,
Department of Surgery, Division of Plastic Surgery,
Southern Illinois University School of Medicine