What is the recommended treatment for scaphoid fracture nonunion?

Treatment of Scaphoid Fracture Nonunion

Scaphoid nonunion should be treated surgically with open reduction, internal fixation (preferably with a Herbert screw or cannulated screw), and bone grafting—either iliac crest cancellous bone graft or vascularized bone graft, particularly when avascular necrosis of the proximal pole is present. 1, 2

Surgical Approach and Technique

Standard Surgical Treatment

• Open reduction and internal fixation with bone grafting is the definitive treatment for scaphoid nonunion, achieving union rates of approximately 90% with conventional techniques 1
• K-wire fixation combined with iliac crest cancellous bone graft achieves 100% union rates in contemporary series, including 44% of cases involving proximal pole fractures 2
• Herbert screw fixation with bone grafting produces union in 82% of cases (23 of 28 fractures), though surgical approach and graft type significantly influence outcomes 3
• Cannulated screw fixation (3.0 mm) with threaded washers achieves 96.25% union rates for acute fractures and remains effective for established nonunions 4

Choice of Bone Graft

For nonunions without avascular necrosis:

• Iliac crest cancellous bone graft is highly effective, achieving 100% union when combined with K-wire fixation 2
• Iliac wedge grafts are superior for correcting humpback deformity and providing initial stabilization compared to cancellous grafts alone 3

For nonunions with avascular necrosis of the proximal pole:

• Vascularized bone grafts are the preferred treatment, particularly for proximal pole nonunions where blood supply is compromised 1, 5
• Pedicled vascularized bone graft from the distal dorsoradial radius achieves 90.28% union rates and is technically straightforward 5, 4
• Vascularized grafts offer decreased immobilization time and higher union rates compared to conventional non-vascularized grafts 5

Surgical Approach Selection

• The volar approach produces better outcomes than the dorsal approach, providing superior visualization of the nonunion site 3
• A dorsal approach may be necessary for certain fracture configurations but is associated with slightly lower success rates 3

Postoperative Management

Immobilization Duration

• Limit postoperative immobilization to avoid stiffness—prolonged immobilization beyond 3 months negatively affects functional outcomes 3
• Vascularized bone grafts allow for shorter immobilization periods compared to conventional grafting techniques 5
• Average time to union is approximately 18 weeks (17.93 weeks) following surgery with K-wire and iliac crest bone graft 2

Factors That Do NOT Affect Union

Time to union is not significantly influenced by:

• Patient age 2
• Fracture location (waist vs. proximal pole) 2
• Smoking status 2
• Alcohol use 2
• Time from injury to treatment 2

Adjunctive Therapies to AVOID

Low-intensity pulsed ultrasound (LIPUS) should NOT be used for scaphoid nonunion treatment:

• No compelling anatomical or physiological evidence supports LIPUS benefit for nonunion or stress fractures 6
• LIPUS does not represent efficient use of healthcare resources given lack of benefit on patient-important outcomes 6
• Healthcare organizations should stop reimbursements for LIPUS based on current best evidence 6

Critical Pitfalls to Avoid

• Do not delay surgical intervention—untreated scaphoid nonunions progress to carpal collapse and degenerative arthritis 1
• Do not use non-vascularized grafts for proximal pole nonunions with AVN—the compromised blood supply requires vascularized bone grafting 7, 1, 5
• Do not immobilize for longer than necessary—excessive immobilization (>3 months) causes stiffness and poor functional outcomes 3
• Do not assume nonunion rate is acceptable—even with surgical treatment, nonunion rates can reach 10%, necessitating meticulous technique 1

Expected Outcomes

• Union rates range from 82-100% depending on technique, with K-wire and iliac crest bone graft achieving the highest success 2, 3, 4
• Satisfactory functional outcomes occur in 81-94% of patients following successful union 4
• Proximal pole fractures can achieve union even with their tenuous blood supply when appropriate techniques are used 7, 2