In an adult with scaphoid non‑union advanced collapse wrist and positive ulnar variance, is proximal row carpectomy combined with ulnar shortening osteotomy the preferred first‑line treatment, and what are its indications, contraindications, and expected outcomes?

Proximal Row Carpectomy for SNAC Wrist

What is Proximal Row Carpectomy?

Proximal row carpectomy (PRC) is a motion-preserving salvage procedure that involves surgical excision of the scaphoid, lunate, and triquetrum bones, creating a new articulation between the capitate and the lunate fossa of the radius. 1, 2

Indications for PRC in SNAC Wrist

PRC is indicated for stage II scaphoid nonunion advanced collapse (SNAC) wrist where degenerative changes are limited to the radioscaphoid joint without capitolunate arthritis. 3, 1, 4

• The procedure is appropriate when the capitate articular surface remains intact, as the success of PRC depends on a healthy capitate-lunate fossa articulation. 2, 4
• PRC is particularly suitable for patients who require shorter postoperative immobilization (3 weeks versus 8-12 weeks for four-corner fusion) and can accept moderate grip strength reduction. 3, 1
• Younger, active patients who prioritize range of motion over maximal grip strength are ideal candidates. 1, 4

Contraindications

The presence of advanced capitolunate arthritis (stage III SNAC) is an established contraindication to PRC, as pain relief may be unsatisfactory and progression to radiocarpal arthritis is likely. 2, 4

• When capitolunate arthritis exists, four-corner fusion with scaphoid excision is recommended instead. 4
• Inflammatory arthropathy affecting the radiocarpal joint is a relative contraindication. 4

PRC Combined with Ulnar Shortening Osteotomy

In patients with positive ulnar variance, combining PRC with ulnar shortening osteotomy addresses both the carpal collapse and ulnocarpal impaction, though this specific combination lacks high-quality comparative evidence. 3

• Positive ulnar variance can cause ulnar-sided wrist pain and accelerate degenerative changes in the ulnocarpal joint. 3
• The ulnar shortening component should be performed to achieve neutral or slightly negative ulnar variance (typically 2-4mm shortening). 3
• This combined approach requires longer immobilization (6-8 weeks) compared to isolated PRC due to the osteotomy healing requirements. 3

Expected Outcomes

PRC achieves 57% of contralateral wrist extension-flexion arc (averaging 75 degrees total), 52% of radial-ulnar deviation (averaging 33 degrees), and 50% of grip strength compared to the unaffected side. 1

• Pain with strenuous activity is reduced by 40%, and resting pain is reduced by 77%. 1
• The mean DASH (Disabilities of Arm, Shoulder, and Hand) score postoperatively is 27.4, indicating mild-to-moderate functional limitation. 1
• Recent meta-analysis demonstrates PRC provides significantly greater postoperative extension, ulnar deviation, and improvement in visual analog scale pain scores compared to four-corner fusion. 5
• Range of motion improvements continue for at least 12 months postoperatively and do not decline with time. 4

Comparative Advantages Over Four-Corner Fusion

PRC demonstrates superior outcomes with lower complication rates compared to four-corner fusion: only 5.2% of PRC patients require conversion to total wrist arthrodesis versus 11% after four-corner fusion. 5, 6

• PRC avoids fusion-specific complications including 8.9% nonunion rate, 2.2% hardware removal rate, and dorsal impingement syndrome seen with four-corner fusion. 5, 6
• Technical ease and shorter immobilization (3 weeks versus 8-12 weeks) favor PRC. 1, 4
• Both procedures provide equivalent grip strength and pain relief. 4, 5, 6

Long-Term Considerations and Complications

The primary long-term concern with PRC is development of radiocarpal arthritis, occurring in approximately 10-15% of patients, though the majority remain asymptomatic. 4, 6

• Three-view wrist radiographs are essential for initial assessment and should include posteroanterior, lateral, and oblique views to evaluate carpal collapse and ulnar variance. 3
• CT without IV contrast should be obtained when detailed surgical planning is needed or when assessing bone deformity prior to PRC. 3
• MRI without contrast is appropriate for screening proximal scaphoid pole viability and detecting associated soft-tissue injuries that may alter the surgical approach. 3

Postoperative Management

Standard postoperative care includes immobilization in a plaster cast for 3 weeks, during which active finger-motion exercises must be performed to prevent finger stiffness, a common disabling complication. 3

• Progressive mobilization and strengthening begin after cast removal once the patient is pain-free. 3
• Clinical follow-up focuses on pain-free status and functional restoration rather than routine repeat imaging. 3

Critical Pitfalls to Avoid

Do not perform PRC in the presence of capitolunate arthritis, as this leads to unsatisfactory pain relief and high conversion rates to total wrist arthrodesis. 2, 4

• Obtaining fewer than three radiographic views can lead to missed diagnoses of capitolunate involvement and inappropriate patient selection. 3
• Proximal-pole scaphoid fractures carry higher risk of avascular necrosis; these patients need MRI evaluation before proceeding with PRC. 3
• Failure to address concomitant positive ulnar variance may result in persistent ulnar-sided pain despite successful PRC. 3