Stability of the Basal Joints of the New Thumb After Pollicization for Thumb Hypoplasia

Nathan D Trist; Michael A Tonkin; Dirk J van der Spuy; Albert Yoon; Harvinder P Singh; Richard D Lawson

doi:10.1016/j.jhsa.2015.04.024

Stability of the Basal Joints of the New Thumb After Pollicization for Thumb Hypoplasia

J Hand Surg Am. 2015 Jul;40(7):1318-26. doi: 10.1016/j.jhsa.2015.04.024.

Authors

Nathan D Trist¹, Michael A Tonkin², Dirk J van der Spuy¹, Albert Yoon¹, Harvinder P Singh¹, Richard D Lawson¹

Affiliations

¹ Department of Hand Surgery and Peripheral Nerve Surgery, Royal North Shore Hospital, Children's Hospital at Westmead, University of Sydney, Sydney, Australia.
² Department of Hand Surgery and Peripheral Nerve Surgery, Royal North Shore Hospital, Children's Hospital at Westmead, University of Sydney, Sydney, Australia. Electronic address: mtonkin@med.usyd.edu.au.

PMID: 26095054
DOI: 10.1016/j.jhsa.2015.04.024

Abstract

Purpose: To investigate the presence or absence of union of the new trapezium to the retained metacarpal base after pollicization and to relate this to stability of the new trapezium and the new carpometacarpal joint.

Methods: Thirty-six patients (46 pollicizations) were assessed at clinical review. Mean time from surgery to review was 96 months (range, 9-260 mo). Clinical assessment measured range of motion (ROM) at the carpometacarpal joint, stability of the carpometacarpal joint, and extrinsic and intrinsic strength of both hands. Radiological review evaluated 3 parameters: bony union between the new trapezium and retained metacarpal base, stability of the new trapezium in relationship to the metacarpal base, and carpometacarpal joint stability.

Results: There was radiographic nonunion between the new trapezium and the retained metacarpal base in 8 (1 treated) of 46 pollicizations. Relative risk of instability of the new trapezium was 39 times more likely if nonunion was present. Nine pollicizations were unstable at the carpometacarpal joint, 8 in those with union and 1 with nonunion. Relative risk of instability was 1.4 times more likely for those with union. For patients with nonunion, ROM and grip strength variables were reduced but only grip strength reached statistical significance. In patients with carpometacarpal joint instability, ROM and grip strength variables were reduced but none of the variables reached statistical significance.

Conclusions: This study suggests that when the surgeon is attempting to obtain union of the new trapezium to the retained metacarpal base, failure to do so results in a poorer thumb with a significantly increased risk of trapezial instability and decreased grip strength. There is a mildly increased risk of carpometacarpal joint instability with union, but significantly poorer function as a consequence of this has not been demonstrated.

Type of study/level of evidence: Therapeutic IV.

Keywords: Pollicization; carpometacarpal joint instability; function; trapezium instability.

MeSH terms

Adolescent
Carpometacarpal Joints / abnormalities*
Carpometacarpal Joints / diagnostic imaging
Carpometacarpal Joints / surgery*
Child
Child, Preschool
Female
Hand Strength / physiology
Humans
Infant
Joint Instability / diagnostic imaging
Joint Instability / physiopathology*
Male
Radiography
Range of Motion, Articular / physiology
Thumb / abnormalities*
Trapezium Bone / abnormalities
Trapezium Bone / diagnostic imaging
Trapezium Bone / surgery*
Treatment Outcome