Post-Operative Splinting and Rehabilitation After Extensor Tendon Repair in the Finger
Immediate Post-Operative Immobilization
For extensor tendon repairs in the finger, immobilize the distal interphalangeal (DIP) joint in full extension or 5–10° of hyperextension for 8 weeks continuously using a rigid DIP-extension splint (stack splint or custom-molded splint) that leaves the proximal interphalangeal (PIP) and metacarpophalangeal (MCP) joints free. 1
Critical Splinting Principles
- Use a rigid splint that immobilizes only the DIP joint while allowing the PIP and MCP joints to move freely 1
- Any interruption of the 8-week immobilization period requires restarting the entire immobilization timeline 1
- Never use removable splints for extensor tendon injuries, as patient-controlled removal leads to treatment failure 1
- Custom-fabricated splints are superior to off-the-shelf options for achieving optimal joint positioning 2
Zone-Specific Considerations
For zone III extensor tendon repairs (over the PIP joint), a relative motion flexion orthosis with dorsal hood can be used to protect the repair while allowing controlled motion 3. This approach has demonstrated effectiveness in complex cases involving combined tendon repair and fracture 3.
Early Mobilization Protocol
Begin active range-of-motion exercises of the PIP and MCP joints immediately after splint application to prevent stiffness of adjacent joints 1. This principle of early mobilization of uninjured joints is critical to prevent compensatory movement patterns and muscle deconditioning 1.
Rehabilitation Timeline
- Weeks 0–8: Continuous DIP immobilization with active PIP/MCP motion 1
- Week 8 onward: Initiate controlled DIP mobilization after confirming tendon healing 1
- For uncomplicated mallet finger injuries (dorsal avulsion fractures), strict splint immobilization for the full 8 weeks is mandatory 4
Pain and Edema Management
- Apply ice therapy for 10–20 minutes with a thin towel barrier to control pain and swelling 1
- Topical NSAIDs are preferred over oral NSAIDs for safety during the immobilization period 1
- Never apply heat to the injured finger during the acute phase 1
Red Flags Requiring Urgent Referral
Activate emergency services immediately if the finger appears blue, purple, or pale, indicating possible vascular compromise 1.
Urgent Orthopedic Referral Indications
- Open injuries of the finger 1
- Avulsion fractures involving ≥1/3 of the articular surface of the distal phalanx 1
- Volar subluxation of the distal phalanx on lateral radiograph 1
- Inability to maintain reduction of any associated fracture or dislocation 1
- Persistent, unremitting pain while the splint is in place 1
Common Pitfalls to Avoid
Over-Immobilization Errors
- Do not use resting hand splints that immobilize multiple joints unnecessarily, as this increases muscle deconditioning and promotes compensatory movement patterns 1
- Avoid immobilizing the PIP and MCP joints unless specifically indicated by the injury pattern 1
Premature Mobilization
- Any flexion of the DIP joint during the 8-week immobilization period compromises tendon healing and requires restarting the clock 1
- Patient education about the consequences of splint removal is essential to prevent treatment failure 1
Special Considerations for Complex Injuries
For combined injuries involving extensor tendon repair, phalanx fractures, and PIP joint contractures, a relative motion flexion orthosis with dorsal hood can address all three pathologies simultaneously 3. This approach has demonstrated excellent outcomes with Quick DASH score improvements of 50 points and restoration of near-normal range of motion 3.
Flexor Tendon Injuries (Differential Diagnosis)
If the injury involves forced extension of a flexed DIP joint resulting in inability to flex the fingertip, suspect flexor digitorum profundus avulsion, which typically requires surgical repair rather than splinting alone 4.