Look for treatable targets when choosing osteotomy for distal radius malunions

Surgeon notes that decisions for surgical treatment should not be solely based on radiographs.

With respect to distal radius malunions, David C. Ring, MD, PhD, said that in order to help patients achieve their goals, surgeons should look for a good surgical target.

“The key is that the disability and the patient’s goals need to correspond with an impairment,” Ring said during a presentation at the American Academy of Orthopaedic Surgeons annual meeting. “And the impairment needs to be directly related to malalignment. Finally, it needs to be a malalignment that is straightforward to improve with an operation that has acceptable risks.”

Malalignment with dysfunction

He noted that some patients may have malalignment without dysfunction and warned that surgeons should not solely base decisions for surgical treatment on radiographs. “We have all treated patients who functioned much better that we would guess based on their radiographs alone,” Ring said.

An example of a good surgical target is improved supination via osteotomy that improves the alignment of the distal radioulnar joint. On the other hand, the results of performing an osteotomy for pain are unpredictable, and are best when the pain complaints fit the deformity, for example ulnocarpal impingement pain in the setting of axial shortening.

David C. Ring

Osteotomies

With the advent of locking plate fixation, the surgeon can use cancellous autograft to fill the defect created by osteotomy and realignment. This limits the defect in the iliac crest created by obtaining a structural graft.

On the other hand, Ring said, “One advantage to a structural bone graft is that a smaller implant can be used, which may limit the potential for extensor tendon irritation, particularly when dorsal implants are used.”

A dorsally angulated extra-articular malunion can be addressed from volar using the so-called extended flexor carpi radialis approach described by Jorge Orbay, which includes releases of the brachioradialis and the dorsal periosteum. Ring described this technique, which recreates the fracture site in malunions treated within 3 to 4 months of injury by taking down the callus bone, release or lengthening of the brachioradialis, elevation of the dorsal periosteum from the radial shaft, and cutting of the dorsal periosteum.

These lateral (left) and AP radiographs show a patient with a distal radius malunion with shortening, dorsal and radial tilt of the articular surface and articular malunion.

“Then it will act like a fresh fracture, at that point, and you can get a better alignment in a fairly straightforward manner,” he said.

Articular osteotomies are much easier to address when the original fracture site can still be identified. This is a particularly difficult procedure, and the most important aspect is appropriate patient and fracture selection.

Standard of care

During the discussion session, an audience member noted that there are many treatment modalities for acute injuries and that the treatment of these injuries often results in legal disputes. “In terms of malunion is there any standard of care that lawyers can really hang their hat on?” the audience member asked.

“My understanding is that distal radius malunion is a common cause of lawsuits,” Ring said. “I have reviewed a few cases. The only thing that is difficult to defend is if you do not discuss and document the risk of fracture redisplacement and malalignment, and also document that you had that discussion with the patient. … Everything else from cast immobilization, to pinning, to plating is within the standard of care.”

The patient has good motion that would be difficult to improve upon with osteotomy. Images: Ring DC

For more information:

• David C. Ring, MD, PhD, can be reached at Yawkey Center, 55 Fruit St., Yawkey 2100, Boston, MA 02114; 617-724-3953; e-mail: dring@partners.org. He receives royalties from DePuy and Wright Medical Technology; is a member of the speakers bureau for Acumed, DePuy and Synthes; is a paid consultant or employee of Acumed and Wright Medical Technology; has received research or institutional support from AcuMed, Biomet, SBI, Smith & Nephew, Tornier and Wright Medical Technology; and has stock options in Mimedex and Illuminoss.

Reference:

• David C. Ring, MD, PhD. Distal radius malunion. Symposium L: Distal radius fractures: New concepts in treatment. Presented at the American Academy of Orthopaedic Surgeons 76th Annual Meeting. Feb. 25-28, 2009. Las Vegas.