Issue: March 2020
Disclosures: Erdman is a committee member for the Orthopaedic Trauma Association. Ghiassi has stock options in Carbofix and is on the editorial/governing board for the Journal of Hand Surgery. Nakata and Nicholson report no relevant financial disclosures.
March 16, 2020
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50-year-old woman with ulnar-sided wrist pain

Issue: March 2020
Disclosures: Erdman is a committee member for the Orthopaedic Trauma Association. Ghiassi has stock options in Carbofix and is on the editorial/governing board for the Journal of Hand Surgery. Nakata and Nicholson report no relevant financial disclosures.
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Joshua D. Johnson

A 50-year-old right-hand-dominant woman with a history of a left distal radius fracture presented to the orthopedic clinic 5 weeks after a ground-level fall. She was told at the time of her initial injury that she had sustained a distal radius fracture, but she did not feel an urgency to follow up because she had a low-demand occupation. At her initial visit, there was no gross motion at the fracture site and the patient was not interested in operative intervention. Subsequently, she was lost to follow-up until 3 months post-injury. At that time, she reported a pain-free period after her last visit followed by new onset ulnar-sided left wrist pain that occurred mostly during pushing and pulling activity. On exam, the patient was noted to have minimal radial- sided tenderness. On the ulnar side, there was significant tenderness over the extensor carpi ulnaris. Range of motion testing revealed 20° less wrist extension compared with the contralateral side.

Nicholas A. Trasolini

Radiographs demonstrated a healed distal radius fracture with 3-mm shortening, 26° volar angulation and 9° greater radial inclination compared with the contralateral side (Figures 1 and 2). The patient had a positive ulnar variance of 2 mm vs. neutral ulnar variance in the uninjured wrist.

Presentation 
1. Posteroanterior (PA) and lateral radiographs of the left wrist demonstrate a volar shear type distal radius malunion with more than 2 mm of ulnar variance, 34° radial inclination and 26° volar angulation.2. PA and lateral radiographs of the contralateral wrist show 0 mm of ulnar variance, 25° radial inclination and neutral angulation in the sagittal plane.

What is your diagnosis?

See answer on the next page.

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Distal radius malunion

After radiographs revealed a distal radius malunion with positive ulnar variance, surgical options were discussed with the patient including distal radius osteotomy, ulnar shortening osteotomy and distal ulnar resection. The patient ultimately elected to have a distal radius osteotomy for correction of her malunion. Five months after injury, the patient underwent left distal radius volar opening wedge osteotomy with internal fixation using a volar locking plate. She was transitioned to a removable, short arm wrist brace with progressive range of motion at 6 weeks postoperatively and was allowed to begin weight-bearing 8 weeks after surgery. At final follow-up 20 weeks after surgery, the patient was pain free, non-tender, and had regained 50° wrist flexion and 50° wrist extension. Radiographs showed bony union, neutral tilt and radial inclination improved to 31° (Figure 3).

Discussion

Distal radius fractures account for 3% of all upper extremity fractures, totaling nearly 640,000 distal radius fractures a year in the United States. Distal radius malunion has been associated with poor functional outcomes, leading to an increasing incidence of operative management of these injuries. Paul J. MacKenney, MD, FRCS (Tr & Orth), and colleagues reported that nearly one-third of patients treated with in situ cast immobilization and two-thirds of those treated with closed reduction and casting would have otherwise gone on to malunion if not converted to operative treatment. Moreover, approximately 20% of patients who underwent nonoperative management would develop functional impairments negatively affecting their clinical outcomes. While the definition of malunion varies, it has been described by Muhanned Ali, MD, and colleagues as dorsal angulation greater than 10°, 3 mm of positive ulnar variance and/or radial inclination of less than 15°.

Whether treated nonoperatively or operatively, distal radius malunion is a potential adverse outcome and management principles are important to understand for all who treat distal radius fractures. Improper restoration of the orientation of the preinjury articular surface can lead to radial shortening and, subsequently, radioulnar disturbances that can cause disruption in radioulnar joint biomechanics. Specifically, ulnar-sided wrist pain is common in the setting of distal radius malunion and may be attributed to triangular fibrocartilage injury, distal radioulnar joint (DRUJ) incongruity or secondary ulnar impaction syndrome. An increased radioulnar variance of just 2.5 mm can increase the ulnocarpal joint forces by 42%, a study by Andrew K. Palmer, MD, and colleagues showed.

Multiple surgical options can address distal radius malunion. For most patients, corrective osteotomy of the radius is the mainstay of treatment. However, depending on the degree of malunion and the patient’s functional requirements, ulnar shortening osteotomy and distal ulnar resection are alternative options for the management of ulnar-sided wrist pain.

Distal radius corrective osteotomy is the preferred option to treat most distal radius malunions if the articular surface is intact or has minimal damage. By restoring anatomic parameters of the distal radius, secondary benefits include restoration of DRUJ congruity, restoration of carpal alignment and alleviation of ulnocarpal impaction. Options for corrective osteotomy include opening and closing wedge osteotomy. Opening wedge osteotomy carries the advantage of restoring distal radial length. Opening wedge osteotomy has traditionally employed the use of bone graft or bone graft substitute, however this notion has been challenged by recent literature, which suggests bone graft is not necessary. In a study by Kagan Ozer, MD, and colleagues, there was no difference in the maintenance of radiographic alignment, time to union, union rate or DASH scores when comparing patients who did or those who did not receive bone graft at the time of opening wedge osteotomy. An alternative option is a closing wedge osteotomy, which allows for direct bone-to-bone contact. As it shortens an already short radius, concomitant ulnar shortening osteotomy is typically indicated.

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Ulnar side symptoms

12 weeks postop 
3. PA and lateral radiographs 12 weeks after osteotomy and open reduction and internal fixation show bony healing, radial inclination of 31° and radioulnar deviance of -1.5 mm.

For older patients and patients with lower functional requirements who have a distal radius malunion, addressing the symptomatic ulnar side of the wrist is an option that has been associated with shorter operative time, fewer complications, a lower incidence of hardware removal and more reliable correction of radioulnar variance. Distal ulna resection (the Darrach procedure) involves resection of the ulnar head and has been associated with dorsopalmar instability of the proximal ulna and loss of grip strength. This is often reserved for refractory cases or low-demand patients.

The patient in the present case underwent an opening wedge distal radius osteotomy without bone graft. She had evidence of union on follow-up, resolution of her ulnar impaction syndrome and regained a flexion-extension arc of 100°.

Key points are as follows:

Distal radius fractures are a common injury and, when treated nonoperatively, can go on to malunion and cause significant disability;

The treatment for distal radius malunion involves varying osteotomy options with or without bone graft, but it is important to consider the 3D nature of this problem; and

The primary treatment option should be radial osteotomy to restore the native anatomy, but ulnar-sided procedures may be indicated in a sub-group of patients.

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Disclosures: Erdman is a committee member for the Orthopaedic Trauma Association. Ghiassi has stock options in Carbofix and is on the editorial/governing board for the Journal of Hand Surgery. Nakata and Nicholson report no relevant financial disclosures.

Editor's Note: This article was updated on April 13, 2020, to correct the order in which Figures 1 and 3 appear.