Mallet Finger Rehabilitation Protocol

This protocol outlines a comprehensive physical therapy rehabilitation program for Mallet Finger injuries. It is important to note that progression through each phase is dependent on individual patient progress and physician approval. This protocol is a guideline and should be adapted to each patient's specific needs.

I. Pathophysiology

Mallet finger, also known as baseball finger, is a deformity of the distal interphalangeal (DIP) joint resulting from disruption of the extensor tendon mechanism. This disruption prevents active extension of the DIP joint, causing it to rest in a flexed position. The injury can be caused by a forceful blow to the fingertip, such as being struck by a ball, or from a hyperextension force. The disruption can involve either a complete rupture of the extensor tendon or an avulsion fracture of the dorsal base of the distal phalanx where the tendon inserts. Prompt and appropriate management is crucial to prevent long-term stiffness, pain, and functional limitations. Failure to treat properly can lead to a Swan Neck Deformity.

II. Examination and Evaluation

A thorough examination is necessary to establish a baseline and guide treatment. This includes:

• Subjective History: Mechanism of injury, pain level, functional limitations, and prior treatment.
• Observation: Note the resting posture of the DIP joint (flexion), swelling, ecchymosis.
• Palpation: Assess for tenderness over the dorsal DIP joint, and any bony crepitus.
• Range of Motion (ROM): Measure active and passive DIP joint extension and flexion. Assess PIP joint ROM as well.
• Strength Testing: Assess strength of DIP joint extension. Be cautious and avoid aggressive testing in early phases.
• Sensory Examination: Rule out nerve involvement.
• Vascular Examination: Assess capillary refill.

III. Special Tests

• Mallet Finger Test: Observe the resting position of the DIP joint (flexed). Ask the patient to actively extend the DIP joint. Inability to actively extend indicates a positive test.
• Extensor Lag Test: Measure the difference between passive and active DIP joint extension. A significant difference indicates an extensor lag and a positive test.

IV. Rehabilitation Protocol

Phase I: Protection (0-6/8 Weeks)

Goals: Protect the healing extensor tendon, minimize pain and edema, maintain PIP joint mobility.

• Immobilization: Continuous splinting of the DIP joint in full extension or slight hyperextension (0-10 degrees) for 6-8 weeks. Splint should be custom-made or properly fitted to ensure adequate support and prevent skin breakdown. Ensure the PIP joint is free to move.
• Edema Management: Elevation of the hand, ice packs for 15-20 minutes several times a day. Gentle AROM of unaffected fingers (PIP and MCP joints).
• Patient Education: Proper splint care, hygiene, and importance of compliance with immobilization. Emphasize the need to avoid any DIP joint flexion during this phase.
• AROM of Unaffected Joints: Encourage AROM of the wrist, MCP, and PIP joints to prevent stiffness.

Phase II: Loading (6/8-10/12 Weeks)

Goals: Gradually restore active DIP extension, maintain PIP joint mobility, and begin light strengthening exercises.

• Splint Weaning: Begin gradual splint weaning as directed by the physician, typically involving periods of splint removal for exercise and hygiene. Start with brief periods (e.g., 3 times a day for 15 minutes initially).
• Active Range of Motion (AROM): Gentle AROM exercises for DIP extension and flexion, focusing on achieving full active extension. Start with gravity-assisted exercises and progress as tolerated.
• Blocking Exercises: PIP blocking exercises to isolate DIP extension.
• Strengthening: Begin with gentle isometric exercises for DIP extension, gradually increasing resistance as tolerated. Consider putty exercises for grip strength.
• Scar Management: If there is a scar, begin scar massage and mobilization to prevent adhesions.
• Continue Edema Management as Needed: Continue elevation and ice as needed.
• Splinting at Night: Typically, the splint will be worn at night during this phase to prevent flexion during sleep.

Phase III: Return to Function (10/12+ Weeks)

Goals: Restore full ROM and strength, improve hand function, and return to previous activity level.

• Progressive Strengthening: Increase resistance during strengthening exercises using weights, theraband, or putty.
• Functional Activities: Incorporate functional activities that mimic activities of daily living (ADLs) and work-related tasks.
• Proprioceptive Exercises: Exercises to improve joint position sense and coordination.
• Continue Scar Management as Needed.
• Gradual Return to Sport/Activity: Progressively increase the intensity and duration of activities, ensuring proper technique and avoiding re-injury. Consider protective taping or splinting during activities that pose a risk to the DIP joint.
• Monitor for Extensor Lag: Regularly assess for any recurrence of extensor lag. If an extensor lag develops, consider a period of splinting.

Important Considerations:

• Patient education is crucial throughout the rehabilitation process.
• Adherence to the splinting protocol is essential for successful healing.
• Progression through each phase should be guided by patient symptoms and clinical findings.
• Consult with the physician if there are any concerns or if the patient is not progressing as expected.
• Individualize the protocol based on the patient’s specific needs and goals.