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(1) Background: Patients treated with the two previous generations of ulnarization developed a bump related to the ulnar head becoming prominent on the radial side of the hand. To finally remedy this problem, a third generation of ulnarization was developed to keep the ulnar head contained. While still ulnar to the wrist center, the center of the wrist remains ulnar to the ulnar head, with the ulnar head articulating directly with the trapezoid and when present the trapezium. (2) Methods: Between 2019 and 2021, 22 radial club hands in 17 patients were surgically corrected with this modified version of ulnarization. (3) Results: In all 17 patients, the mean HFA (hand–forearm-angle) correction was 68.5° (range 12.2°–88.7°). The mean ulna growth was 1.3 cm per year (range 0.2–2 cm). There were no recurrent radial deviation deformities more than 15° of the HFA. (4) Conclusions: This new version of ulnarization may solve the problem of the ulna growing past the carpus creating a prominent ulnar bump. The results presented are preliminary but promising. Longer-term follow-up is needed to fully evaluate this procedure.

Radial club hand is a complex congenital abnormality of the radial or pre-axial border of the upper extremity. It has a wide range of phenotypes from hypoplasia of the thumb to complete absence of the radius and the first ray. Centralization with tendon transfer is a popular method for maintaining the correct position of radial club hand. On the other hand, various corrections were devised,e.g. radialization after distraction to emphasize the fact that the head of the ulna is positioned under the radial carpal bones and is no longer placed in a slot in the center of the carpus, microvascular epiphysis transfer, gradual correction using Ilizarov method, for Bayne Type III or Type IV. We should pay attention to the recurrence of radial deformity or circulatory impairment with the tension. Lunate excision or ulnar shortening can be selected for tension-free correction. Radialization can be indicated for avoiding the recurrence of radial flexion. However, we should pay attention of the radial protrusion of the ulnar head. For avoiding the recurrence of radial deformity or circulatory impairment, gradual correction using Ilizarov external fixation can be indicated, especially in the cases with severe radial deviation or with short forearm. In the mild cases, Bayne Type I or Type II, radius lengthening is accompanied by a soft-tissue distraction or release at the ulnar carpal joint with keeping wrist and forearm motion without producing growth plate damage.

Recurrent deformity from centralization and radialization led to the development in 1999 of a new technique by the author called ulnarization. This method is performed through a volar approach in a vascular and physeal sparing fashion. It biomechanically balances the muscle forces on the wrist by dorsally transferring the flexor carpi ulnaris (FCU) from a deforming to a corrective force. The previous problems of a prominent bump from the ulnar head and ulnar deviation instability were solved by acutely shortening the diaphysis and by temporarily fixing the station of the carpus to the ulnar head at the level of the scaphoid. This is the first report of this modified Paley ulnarization method, which the author considers a significant improvement over his original procedure.