Many surgical procedures have been developed over the years to treat the deformity of Radial Club Hand. Some of these procedures include:
Distal Ulnar Osteotomy
Centralization is a technique in which the carpus is placed over the center of the distal end of the ulna. It was considered the gold standard for RCH treatment for many years. However, the treatment was plagued by partial or complete recurrence of the RCH deformity.
An alternative to Centralization was proposed by Buck-Gramcko, which he termed Radialization. With Radialization, the hand and carpal bones are translocated to the ulnar side of the ulnar head. In addition, the extensor and flexor carpi radialis (FCR) tendons are transferred to the ulnar side to weaken the forces of radial deviation and strengthen the ulnar motors. The name Radialization refers to conversion of the ulna into a radius. Buck-Gramcko’s technique resulted in much lower recurrence rates compared to Centralization. The radialization technique works using the following rationale:
Create a fulcrum to the radial deviation forces of the forearm without impeding wrist motion
Balance muscle forces on the radial and ulnar sides of the wrist using tendon transfers
In 1999 Dr. Paley developed a new procedure to treat RCH based on a modification of the Buck-Gramcko Radialization. He termed the procedure an Ulnarization to describe the direction of movement of the carpus relative to the forearm (ulna) and to distinguish it from Radialization, which is performed differently.
The development of the Ulnarization procedure was based on some of Dr. Paley’s observations of the Radialization procedure. First, Radialization is performed through a dorsal incision (top of the hand), resulting in poor to no visualization of the neurovascular structures as well as excessive dissection of the ulna. In Dr. Paley’s Ulnarization approach, the incision is volar (palm side) which allows visualization of the neurovascular structures of the hand and limits dissection of the ulna. Second, the flexor and extensor carpi radialis tendons, which are transferred to balance the wrist in the Radialization procedure, are usually absent and thus unavailable for transfer. In the Ulnarization technique, the flexor carpi ulnaris (FCU) is transferred to balance the wrist. Unlike the other tendons, the FCU is always present and never hypoplastic. Lastly, the term Radialization is confusing in English. Ulnarization more accurately describes the procedure.
One of the major goals of the Ulnarization surgery is to correct the poor grip strength in individuals with RCH. Poor grip strength is due to:
Lack of a fulcrum
Forearm shortening affects muscle length curve
Excessive palmar flexion pull: dorsi flexion of hand increases grip strength
To easily understand this, try flexing your wrist downwards, palm side down, and then try and make a fist. You will find it is much more difficult to make a fist then it is with your wrist in a neutral position. In order to correct this, Dr. Paley transfers the flexor carpis ulnaris (FCU) tendon which will give a stronger grip force.
To learn more about the Ulnarization, read our recent publication in SICOT:
The Paley ulnarization of the carpus with ulnar shortening osteotomy for treatment of radial club hand
In the Ulnarization technique, Dr. Paley converts the head of the ulna into the fulcrum. This makes recurrence impossible since the ulna physically blocks the wrist from reverting to the deformed position. The FCU is transferred from the palmar side to the dorsum (top) of the wrist. The FCU is a very strong tendon and transferred becomes the new extensor for the wrist, allowing increased grip strength and finger range of motion.