What is the treatment for avulsion fractures and possible flexor tendon avulsion of the fifth digit of the left hand?

Treatment of Avulsion Fractures and Possible Flexor Tendon Avulsion of the Fifth Digit

For your fifth digit injury with suspected bony avulsion fragments at the PIP joint and possible flexor tendon involvement, immediate surgical referral is indicated, as all flexor digitorum profundus (FDP) tendon avulsions should be surgically repaired as soon as possible regardless of fracture pattern. 1

Initial Diagnostic Workup

Your current radiographs showing small bony densities are insufficient for complete evaluation:

• Obtain at least 3-view radiographs of the affected digit to properly assess fracture pattern, displacement, and articular involvement 2, 3
• MRI is the definitive imaging modality if flexor tendon avulsion is suspected, with sensitivity of 92-100% and specificity of 100% for detecting tendon injuries, level of retraction, and associated pulley injuries 2
• Critical pitfall: Fracture patterns on x-ray are unreliable in predicting the actual location of retracted tendon ends—the tendon often retracts farther than radiographs suggest 1

Surgical Timing and Indications

Urgent surgical repair within 7-10 days is mandatory for the following reasons:

• All FDP avulsion injuries seen within 10 days require operative reattachment of the profundus tendon 4
• Delayed diagnosis beyond 10-14 days significantly complicates treatment and worsens functional outcomes 4, 5
• Surgical intervention is specifically indicated when:
  • Displacement >3mm is present 3
  • More than one-third of articular surface is involved 2, 3
  • Interfragmentary gap >3mm exists 3
  • Any flexor tendon avulsion is confirmed or suspected 1, 4

Surgical Approach

• Single midlateral incision allows access to both the avulsed bony fragment and retracted tendon 6
• Bony fragments should be replaced and fixed with 1.5mm screws when adequate size permits 6
• Direct tendon reattachment to bone is performed when fragment is too small for fixation 4
• Intraoperative assessment must evaluate: pulley system integrity, tendon quality, and degree of retraction 2, 7

Post-Operative Management

Rigid immobilization for 3-6 weeks followed by aggressive early motion is the standard protocol:

• Splinting protects the repair during initial healing 3
• Active finger motion exercises must begin immediately after immobilization period to prevent stiffness, which is the most functionally disabling complication 3
• Critical pitfall: Failure to encourage early finger motion leads to significant stiffness that becomes extremely difficult to treat after fracture healing 3
• Home exercise programs moving fingers through complete range of motion are effective and minimize stiffness risk 3

Special Considerations for Fifth Digit

Your injury pattern may represent an unclassified variant of FDP avulsion:

• Fifth digit injuries can involve intra-articular fractures with multiple fragments, one attached to retracted tendon and another incarcerated at the A4 pulley 7
• These complex patterns require individualized surgical planning based on MRI findings 7, 6
• Simultaneous dorsal and volar base fractures, though rare, have been reported in the fifth digit and require comprehensive fixation 6

Antibiotic Prophylaxis

• Not indicated for closed avulsion fractures
• Only required if there is open fracture with soft tissue disruption 3

Follow-Up Red Flags

Unremitting pain during follow-up warrants immediate reevaluation as this may indicate:

• Inadequate fixation 3
• Pulley system injury 2
• Tendon adhesions or re-rupture 2