What is the treatment for a minimally displaced fracture of the base of the proximal phalanx of the 5th finger?

Treatment of Minimally Displaced Proximal Phalanx Base Fracture of the 5th Finger

For a minimally displaced fracture of the base of the proximal phalanx of the 5th finger, treat with rigid immobilization in an intrinsic-plus position (wrist extended 30°, metacarpophalangeal joint flexed 70-90°) for 3-6 weeks combined with immediate active interphalangeal joint motion exercises. 1

Initial Assessment

Before initiating treatment, obtain proper imaging and assess for features requiring surgical referral:

• Obtain at least 3-view radiographs (posteroanterior, lateral, and oblique) to properly evaluate fracture pattern, displacement, and articular involvement 1
• Examine for malrotation by having the patient actively flex all fingers into a fist—scissoring of the small finger over or under the ring finger indicates rotational malalignment requiring immediate surgical referral 1
• Assess for surgical indications: displacement >3mm, articular involvement >1/3 of joint surface, interfragmentary gap >3mm, or clinical malrotation all warrant orthopedic referral 1

Conservative Treatment Protocol

For truly minimally displaced fractures without the above surgical indications:

Immobilization Technique

• Apply rigid splinting in the intrinsic-plus position: wrist dorsiflexed 30°, metacarpophalangeal joint flexed 70-90° 2
• This position tightens the extensor aponeurosis to cover two-thirds of the proximal phalanx, providing firm fracture splinting 2
• Duration: 3-6 weeks of rigid immobilization 1
• Buddy taping to the 4th digit is an effective alternative that allows immediate mobilization and has shown excellent outcomes specifically for 5th digit proximal phalanx base fractures 3

Early Motion Protocol

• Begin immediate active interphalangeal joint exercises while maintaining metacarpophalangeal immobilization 1
• Active finger motion does not adversely affect adequately stabilized fractures and prevents the most functionally disabling complication—stiffness 4
• Instruct patients to move fingers regularly through complete range of motion to minimize stiffness risk 1

Follow-Up Monitoring

• Obtain repeat radiographs at 10-14 days to ensure fracture position is maintained 1
• Continue radiographic monitoring for 3 weeks and at cessation of immobilization 1
• A home exercise program is effective after fracture immobilization without requiring formal supervised therapy 1

Expected Outcomes

The evidence strongly supports conservative management for this specific fracture pattern:

• In a prospective study of 53 consecutive 5th digit proximal phalanx base fractures treated with buddy taping and immediate mobilization, all but one patient regained full flexion, with high overall satisfaction and only 3 cases of malrotation (none requiring surgery) 3
• Dynamic treatment protocols achieve bone healing and full active motion simultaneously in most patients by 6 weeks 2

Critical Pitfalls to Avoid

• Do not use static immobilization of all finger joints—this leads to severe stiffness and poor functional outcomes 2
• Do not miss rotational malalignment—always assess finger cascade during active flexion before initiating treatment 1
• Compression-type fractures may not be suitable for traction splinting due to tenodesis effects causing flexion deficits 5
• Reassess at 10-14 days—early loss of reduction can occur and requires prompt intervention 1