Long-Term Outcomes of Huber Opposition Transfer for Augmenting Hypoplastic Thumb Function

Area of Science:

• Orthopedic surgery
• Hand surgery
• Pediatric orthopedics

Background:

• Hypoplastic thumbs, specifically types II and IIIA, present significant functional deficits.
• The Huber opposition transfer is a surgical technique used to address thumb hypoplasia.

Purpose of the Study:

• To report the functional outcomes of the Huber opposition transfer (using the abductor digiti minimi muscle) in patients with types II and IIIA hypoplastic thumbs.
• To evaluate long-term results, with a minimum follow-up of 5 years.

Main Methods:

• A retrospective study including 21 thumbs (15 type II, 6 type IIIA) that underwent Huber opposition transfer.
• Functional outcomes assessed via range of motion, pinch strength, and validated questionnaires (PODCI, PROMIS).
• Patients were evaluated either through direct examination (12 thumbs) or medical record review (9 thumbs).

Main Results:

• Limited range of motion was observed in the interphalangeal and metacarpophalangeal joints.
• Key and tripod pinch strength were 44% and 65% of normal, respectively.
• High subjective scores (PODCI, PROMIS) indicated good global function, upper extremity use, happiness, and pain management, though parent-reported physical function showed some limitations. Revision surgery was needed in 22% of cases, mainly for instability.

Conclusions:

• The Huber opposition transfer demonstrates favorable subjective outcomes in the long term for type II and IIIA hypoplastic thumbs.
• While range of motion and strength may be compromised, the procedure effectively improves overall function and patient satisfaction.
• Persistent instability remains a concern, necessitating careful surgical technique and patient selection.