What are the consequences of splinting a 61‑year‑old man’s right ring finger on the volar side with hyperextension of the distal phalanx?

Splinting a Finger on the Volar Side with Hyperextension of the Distal Phalanx: Consequences and Risks

Splinting a finger on the volar (palmar) aspect with the distal phalanx hyperextended is inappropriate and potentially harmful, as it can cause volar plate injury, flexion contracture, joint instability, and compromised finger function. 1

Why This Splinting Technique Is Problematic

Risk of Volar Plate Injury

• Hyperextension of the distal interphalangeal (DIP) joint places excessive stress on the volar plate, which is the primary restraint against hyperextension forces. 2
• Forced hyperextension can rupture the volar plate, leading to dorsal dislocation in the acute phase and chronic complications including post-traumatic hyperextension deformity or paradoxical flexion contracture. 2
• These late complications are difficult to treat but preventable with proper initial splinting technique. 2

Incorrect Immobilization Position

• For mallet finger (extensor tendon injury), the DIP joint should be immobilized in full extension or 5-10° of hyperextension only at the DIP joint itself, not with volar-sided splinting that forces the entire finger into hyperextension. 1, 3
• The splint must be rigid and positioned on the dorsal aspect of the finger to maintain DIP extension while allowing the proximal interphalangeal (PIP) and metacarpophalangeal (MCP) joints to move freely. 1
• Volar splinting that hyperextends the distal phalanx creates abnormal joint mechanics and prevents proper healing of extensor tendon injuries. 4

Risk of Adjacent Joint Stiffness

• Immobilizing multiple joints unnecessarily (which occurs with improper volar splinting) increases muscle deconditioning, promotes compensatory movement patterns, and worsens overall hand function. 1
• The PIP joint is particularly vulnerable to stiffness from unnecessary immobilization and must remain free to move during DIP joint treatment. 5, 6
• Active motion exercises of the PIP and MCP joints should begin immediately after proper splint application to prevent adjacent joint contractures. 1

Potential for Treatment Failure

• Any interruption in proper DIP extension splinting requires restarting the entire 8-week immobilization period for mallet finger injuries. 1
• Improper splint positioning (such as volar placement with hyperextension) does not maintain the correct therapeutic position and will result in treatment failure. 3

Correct Splinting Approach

For Extensor Tendon Injuries (Mallet Finger)

• Use a dorsal stack splint or custom-molded splint that immobilizes only the DIP joint in full extension or 5-10° of hyperextension for 8 weeks continuously. 1, 3
• The splint must be rigid and non-removable, as patient-controlled removal leads to treatment failure. 1
• Leave the PIP and MCP joints completely free to move. 1

For Volar Plate Injuries

• If volar plate rupture is suspected (from hyperextension trauma), the finger should be splinted in slight flexion (15-30°), not hyperextension, to allow volar plate healing. 4, 2
• Intensive physiotherapy during follow-up is essential to prevent chronic flexion contracture or hyperextension deformity. 2

Red Flags Requiring Immediate Action

• Activate emergency services if the finger appears blue, purple, or pale, indicating vascular compromise from improper splinting or underlying injury. 7, 1
• Urgent referral is required for open injuries, avulsion fractures involving ≥1/3 of the articular surface, volar subluxation on radiograph, or inability to maintain reduction. 1
• Persistent, unremitting pain while the splint is in place requires immediate re-evaluation for complications. 1

Pain Management During Proper Immobilization

• Use ice therapy for 10-20 minutes with a thin towel barrier to control pain and swelling; heat application is contraindicated. 1
• Topical NSAIDs are preferred over oral NSAIDs for safety during the immobilization period. 1