How to manage a 2-month-old 4th metacarpal (fourth finger) fracture?

Management of a 2-Month-Old 4th Metacarpal Fracture

At 2 months post-injury, this fracture is already healed or healing in malposition, making this a question of managing an established malunion rather than an acute fracture. The key decision is whether the current position is functionally acceptable or requires corrective surgery.

Assessment of Current Functional Status

The critical factors determining whether intervention is needed include:

• Rotational deformity: Any malrotation causing finger overlap during flexion is unacceptable and requires surgical correction 1, 2
• Angulation: Dorsal angulation >30 degrees in the 4th metacarpal may warrant correction, though the 4th and 5th metacarpals tolerate more angulation than the 2nd and 3rd due to greater carpometacarpal mobility 3, 4
• Shortening: >5 mm of shortening can cause functional impairment and may require correction 3, 4
• Articular involvement: Any residual articular incongruency or step-off requires surgical consideration 4

Management Algorithm

If Functionally Acceptable (No rotational deformity, angulation <30°, shortening <5mm):

• Accept the current position and focus on rehabilitation 4
• Initiate aggressive hand therapy to restore range of motion, as stiffness is the primary concern at this stage 1, 2
• Early mobilization is critical to prevent permanent stiffness, even though the fracture healing window has passed 1, 5

If Functionally Unacceptable:

• Surgical correction with corrective osteotomy and internal fixation is indicated 1, 2
• Plate and screw fixation provides the most stable construct for malunion correction, allowing early postoperative motion 1, 2
• Intramedullary fixation or K-wires are less suitable for correcting established malunion 2

Critical Pitfalls to Avoid

• Do not attempt closed reduction at 2 months - the fracture is already consolidated, and closed manipulation will fail 4
• Do not immobilize further - additional immobilization at this stage will only worsen stiffness without improving alignment 5, 4
• Rotational deformity is the most disabling complication - even small degrees of malrotation cause finger scissoring and functional impairment that will not improve with time 1, 2

Specific Treatment Approach

If surgery is not indicated, the patient needs:

• Immediate referral to hand therapy for range of motion exercises 1, 5
• Focus on metacarpophalangeal joint flexion (60-90 degrees) and full finger extension 3
• Buddy taping may assist with mobilization if stiffness is present 3

If surgery is indicated:

• Corrective osteotomy at the malunion site with rigid internal fixation (preferably plate and screws) 1, 2
• Postoperative protocol emphasizing early mobilization to prevent stiffness 1, 5