Reconstruction of hypoplastic thumb using hemi-longitudinal metatarsal transfer

Area of Science:

• Orthopedic Surgery
• Hand Surgery
• Pediatric Orthopedics

Background:

• Pollicization is culturally unfavorable for treating hypoplastic thumbs (Blauth's type IIIb and IV) in the Chinese population, where digit preservation is preferred.
• Existing reconstructive methods may have limitations, necessitating innovative approaches.

Purpose of the Study:

• To evaluate the feasibility and outcomes of using a nonvascularized hemi-longitudinal metatarsal graft for hypoplastic thumb reconstruction.
• To assess functional hand recovery, grip strength, pinch power, and donor site complications.

Main Methods:

• Six patients with modified Blauth's type IIIb and IV hypoplastic thumbs underwent reconstruction with free nonvascularized hemi-longitudinal metatarsal grafts.
• Follow-up averaged 87.7 months, with assessments including the Jebsen hand function test and comparison of grip/pinch strength with the contralateral hand.

Main Results:

• Good overall hand function was achieved, as measured by the Jebsen hand function test.
• Grip strength and pinch power were significantly weaker compared to the unaffected contralateral hand.
• No neurovascular or wound complications occurred; the sole donor site complication was a metatarsal fracture that healed well.
• Donor metatarsals demonstrated hypertrophy and regained normal growth potential, with radiological evidence of linear growth (average 1.5 mm/year).

Conclusions:

• Free hemi-longitudinal metatarsal transfer is a feasible and effective method for reconstructing type IIIb/IV hypoplastic thumbs.
• This technique offers a good functional outcome, enabling the attainment of a five-digit hand with minimal long-term donor site morbidity.