What is the recommended treatment for a young to middle-aged adult with a proximal lunate fracture, negative ulnar variance, and a dorsally angulated articular fracture?

Management of Proximal Lunate Fracture with Negative Ulnar Variance and Dorsally Angulated Articular Fracture

This fracture pattern requires surgical intervention with open reduction and internal fixation to restore articular congruity and prevent post-traumatic arthritis, followed by early active motion protocols. 1

Surgical Indications and Approach

Intra-articular fractures with displacement require surgical fixation to restore joint congruity, particularly when involving the lunate facet with dorsal angulation. 1 The negative ulnar variance in this case increases shear stresses on the lunate, making anatomic reduction critical to prevent progressive carpal instability and avascular necrosis. 2

Surgical Technique Selection

• Open reduction and internal fixation with screws or plates is recommended for complex articular fractures involving the lunate facet. 1
• For dorsally angulated fragments, volar locking plate (VLP) fixation provides stable buttress support, though attention must be paid to capturing small articular fragments. 3
• Post-reduction radiographic parameters should aim for less than 3 mm of radial shortening and less than 10° of dorsal tilt. 1
• Intra-articular gap should be reduced to less than 1 mm to minimize risk of post-traumatic arthritis. 4

Critical Technical Considerations

The dorsally angulated articular fragment requires careful assessment of fragment size and displacement. Studies show that articular portions of dorsal rim fragments measured arthroscopically are smaller than determined by CT, meaning preoperative imaging may overestimate the true articular involvement. 5 However, anatomic reduction remains essential as malunion of the lunate facet is associated with both early functional impairment and late degenerative changes. 4

Postoperative Management Protocol

Immediate Postoperative Period

• Early active motion is critical to prevent stiffness and should be initiated as soon as fracture stability allows. 1
• Finger motion exercises should be initiated immediately after stable fixation is achieved to prevent hand stiffness, one of the most functionally disabling complications. 6, 7
• Buddy taping with adjacent digits provides stability while allowing early active motion. 1
• Dorsal night splinting in 10° flexion helps maintain proper alignment during healing. 1

Rehabilitation Timeline

• Regular radiographic evaluation for the first 3 weeks and at cessation of immobilization is recommended to monitor for loss of reduction. 1
• Early active range-of-motion exercises including all joints of the affected digit should be performed within the first postoperative days. 7, 1
• Above chest level activities should be restricted until fracture healing is evident. 1
• Overly aggressive physical therapy should be avoided as it may increase the risk of fixation failure. 1

Prognostic Factors and Complications

Avascular Necrosis Risk

The negative ulnar variance increases mechanical stress on the lunate, raising concern for avascular necrosis. However, avascular changes of the carpus following wrist injury do not preclude a good result if anatomic reduction of the articular surface is achieved. 8 Early resolution of avascular changes can occur by 9 months with appropriate surgical management. 8

Post-Traumatic Arthritis Prevention

Intra-articular fractures have risk of post-traumatic arthritis if anatomic reduction is not achieved. 1 The goal is to restore articular congruity with less than 1 mm step-off. 4 Displaced dorsal rim fragments in dorsally displaced fractures do not adversely affect wrist clinical outcomes when the articular portion is small (less than 2 mm), but larger fragments require direct fixation. 5

Joint Stiffness Prevention

Joint stiffness is the most common complication, minimized by early active motion. 1 Prolonged immobilization leads to significantly poorer functional outcomes. 7 The balance between stable fixation and early mobilization is critical—fixation must be rigid enough to allow immediate motion protocols. 7

Advanced Imaging Considerations

MRI without IV contrast or CT without IV contrast is usually appropriate as the next imaging study when initial radiographs show acute wrist fracture to fully characterize the fracture pattern and assess for associated ligamentous injuries. 6 MRI shows concomitant ligament injuries, including tears of the scapholunate ligament, which may affect surgical treatment. 6

Salvage Options for Delayed Presentation

If this fracture presents in a delayed fashion with established malunion, early intra-articular corrective osteotomy significantly improves wrist range of motion, grip strength, and functional outcomes when performed within 6 months of injury. 4 For extensive lunate destruction with established Kienböck's disease, proximal row carpectomy may be indicated as a salvage procedure. 2