Sept. 23, 2022

When Keith T. Aziz, M.D., an orthopedic surgeon specializing in hand and upper extremity surgery at Mayo Clinic's campus in Florida, first saw the young basketball player, he noted the boy was not experiencing pain, yet had significant issues with range of motion (ROM).

"He had a pothole in his wrist joint," he says. "His wrist fracture healed in a bad position — and the carpal bones were stuck in the hole."

The reason for the hole present in the boy's wrist joint was an impaction fracture. It was not initially recognized and progressed to a malunion. Distinct from a nonunion, where there is no healing in the joint, a malunion indicates nonanatomic healing, which can be a complication from surgery or something that occurs when nonsurgical management doesn't maintain the appropriate position of the bones.

In the young basketball player's case, no surgery had been performed on his wrist initially, as his health care providers at the time did not recognize the extent of injury. He had a different injury pattern from what is commonly seen in the wrist. In this case, only one part of the joint surface was affected — appearing almost like a die punch in that location — where typical wrist injuries either impact a larger portion of the joint or are outside of the joint altogether. This was a fracture in the scaphoid fossa, part of the joint that supports the scaphoid bone. Though small, this injury and its subsequent malunion caused swelling and limited use of the wrist. In some patients, a wrist malunion can cause the wrist joint to become completely unusable.

Traditional versus cartilage graft wrist fracture repair

A traditional wrist fracture repair would include an osteotomy. However, this procedure, with its usual bone cutting and removal, would be difficult to perform in a contained defect in a small area of the joint surface, says Dr. Aziz.

Due to the nature of the malunion in the basketball player's case, Dr. Aziz elected to take a knee cartilage graft in a non-weight-bearing region to repair the wrist joint. Though this was a unique repair for the player's injury, his parents agreed to pursue it. As the young patient was still skeletally immature with his growth plates open, Dr. Aziz projected and accounted for his future growth in the repair. He also removed the physeal bar that developed from his wrist trauma, as the bar attaches to part of the joint, disallowing growth in line with the bar.

"A knee cartilage graft repair should last the rest of a patient's life once the joint heals correctly," says Dr. Aziz.

Dr. Aziz indicates this repair may have minimal scarring and only slightly less or equivalent ROM than on the uninjured wrist. Today, the basketball player, who had the surgery during training season, continues to do well, has no limitations and has resumed basketball activity. His ROM is now as good and functional as the side with no joint injury.

This surgery's distinction was that it represented the first time a knee cartilage graft technique for wrist malunion was used in a pediatric patient and also for this particular injury.

Applications of the knee cartilage graft for wrist malunion repair

Surgeons can perform the same type of knee cartilage graft for wrist malunion for adults as the basketball player experienced. The procedure is easier to perform in this population — considering future growth is not necessary, as it is in pediatric patients. Wrist joint injury can occur through a number of mechanisms — whether a slip in the kitchen, loss of balance on a neighborhood walk, or a fall while skiing or performing another physical activity. Older adult patients, in particular, experience wrist fractures often and tend to have more significant injuries.

Recovery from the knee cartilage graft procedure to repair the wrist includes casting for a defined period and then a removable orthosis, typically with a 6- to 8-week healing time after which the surgeon will approve use of the joint.

Suggestions for physicians performing the procedure or who elect to refer

Procedures such as cartilage grafting to repair wrist malunion typically are performed by subspecialists — hand and upper extremity orthopedic surgeons — says Dr. Aziz. He suggests the following steps are needed prior to malunion surgery:

• Advanced imaging to characterize the malunion
• Understanding the origin of the wrist malunion
• Confirmation of appropriate diagnosis

After these steps are completed, Dr. Aziz suggests developing a surgical plan or referring to a facility such as Mayo Clinic for the surgery. At the time of initial wrist injury, surgery within two weeks is crucial before the bone begins healing and becomes difficult to position. However, after malunion has occurred in the joint, the time frame in which an orthopedic surgeon must perform the procedure depends on the injury pattern.

"Though no longer considered a medical emergency, the sooner it's repaired, the better — as this protects the articular cartilage," says Dr. Aziz.

For more information

Refer a patient to Mayo Clinic.