We assessed pollicizations performed by one surgeon; compared function of the pollicized digit in patients with and without forearm/wrist anomalies; and determined if hand function changed with age. A total of 42 hands were assessed an average of 5.7 years post-operatively, 21 with a forearm/wrist anomaly (Group 1) and 21 without (Group 2). Fourteen patients with 16 pollicizations were assessed on two occasions 3.5 years apart. Carpometacarpal joint motion was near normal in both groups (decreased retropulsion in Group 1). Metacarpophalangeal and interphalangeal joint flexion, grip, thumb lateral and tip pinch strengths, and Jebsen timed test were superior in Group 2. Subjective assessment by patients/parents found 72% excellent/good results for function and 94% for appearance. Doctor excellent/good assessments were 60% and 70%, respectively. Forearm/wrist anomalies significantly compromised results but are not a contraindication for pollicization. Strength and Jebsen timed test measurements improved at the second assessment of 16 thumbs, but this was consistent with age-related improvement. LEVEL OF EVIDENCE 4.