In an adult patient presenting with post‑traumatic wrist pain, swelling, decreased grip strength, and a clicking sensation, how should a scapholunate ligament tear be evaluated and managed?

Evaluation and Management of Scapholunate Ligament Tear

Begin with conventional radiographs, then proceed directly to CT arthrography for definitive diagnosis, as it achieves nearly 100% sensitivity and specificity—superior to all other imaging modalities—and initiate conservative management for 3-6 months before considering surgical intervention. 1, 2, 3

Initial Diagnostic Evaluation

Clinical Assessment

Look specifically for:

• Watson's scaphoid shift test to assess dynamic instability 4
• Scapholunate ballottement test for joint laxity 4
• Tenderness in the anatomic snuffbox and over the scapholunate interval 4
• Decreased grip strength compared to contralateral side 4
• Clicking or clunking with radial-ulnar deviation 4

Imaging Algorithm

Step 1: Conventional Radiographs

• Obtain PA, lateral, and oblique views with careful attention to positioning 1, 3
• Assess for scapholunate diastasis >4 mm (Terry Thomas sign) 5, 3
• Look for dorsal lunate tilt >10° indicating dorsal intercalated segmental instability (DISI) 5, 3
• Note that radiographs are often normal in low-grade injuries 5

Step 2: Advanced Imaging (if radiographs are normal or nonspecific)

CT arthrography is the gold standard:

• Achieves nearly 100% sensitivity and specificity for scapholunate ligament tears 1, 2, 3
• Detects partial tears more accurately than MR arthrography 1, 3
• Provides greater interobserver agreement than other modalities 1, 3
• Superior for detecting tears of the biomechanically critical dorsal ligament fibers 5

Alternative imaging options (in order of preference):

• MR arthrography (sensitivity 63-100%): Identifies which specific ligament segments are torn—critical for surgical planning 1, 5, 3
• 3T MRI without contrast (sensitivity 65-89%, specificity 90-97%): Commonly used but less accurate than arthrography 1, 5
• High-frequency ultrasound with dynamic "clenched fist" maneuvers (sensitivity 46-100%, specificity 92-100%): Useful for dorsal band tears but operator-dependent 1, 5, 3

Critical Imaging Pitfalls

• Standard 1.5T MRI has only moderate sensitivity (70%) and should not be relied upon for surgical planning 1
• Both MRI and MR arthrography have poor to moderate sensitivity for partial tears 1, 5
• Dynamic instability may be missed on MRI unless sequences are performed in pronation and supination 1, 5
• Do not use MRI alone to assess extrinsic ligaments—accuracy is unknown 1

Management Algorithm

Conservative Management (First-Line for 3-6 Months)

Immobilization Phase (0-6 weeks):

• Immobilize the wrist initially but never exceed 6 weeks to prevent muscular atrophy and joint stiffness 2
• Apply cryotherapy through wet towel for 10-minute periods during acute phase 2
• Modify activities to reduce pain-provoking movements while maintaining some motion 2

Rehabilitation Phase (6 weeks onward):

• Begin gentle range of motion exercises once acute pain subsides (typically 3-6 weeks) 2
• Progress from isometric to eccentric strengthening exercises 2
• Incorporate tensile loading exercises to stimulate collagen production and guide normal collagen fiber alignment 2
• Continue structured rehabilitation focusing on progressive strengthening 3

Expected Outcomes:

• Conservative management achieves significant pain reduction and functional recovery in the majority of patients, particularly when secondary stabilizers remain intact 2

Critical Management Pitfalls

• Never inject corticosteroids into the ligament substance—this inhibits healing, reduces tensile strength, and may cause spontaneous rupture 2
• Avoid prolonged immobilization beyond 6 weeks—leads to muscular atrophy and joint stiffness 2

Follow-Up Protocol

• Assess pain levels, range of motion, and functional improvement regularly 2
• Re-evaluate at 3-6 months: If symptoms persist despite appropriate conservative management, obtain CT arthrography to evaluate for progression or associated injuries 2
• Consider surgical consultation if conservative measures fail by 6 months 2

Surgical Considerations

Indications for Surgery

• Failure of conservative management after 3-6 months 2
• Complete ligament tears with persistent instability 6
• Progressive carpal malalignment on radiographs 6

Surgical Options

The evidence shows no significant difference in outcomes between capsulodesis and ligament reconstruction for chronic scapholunate instability 7:

• Postoperative wrist extension/flexion: 56°/45.6° for capsulodesis vs. 40.9°/47.3° for reconstruction 7
• Scapholunate angle: 60.3° after capsulodesis vs. 56.5° after reconstruction 7
• Scapholunate gap: 3.44 mm after capsulodesis vs. 2.72 mm after reconstruction 7

Important Surgical Caveats

• Current surgical procedures have not consistently maintained radiographic alignment at long-term follow-up 6
• Surgery results in decreased wrist range of motion and strength compared to the contralateral side 6
• Left untreated, scapholunate dissociation can lead to posttraumatic wrist arthritis 6
• Consider combined repair if TFCC injury is also present—arthroscopy may reveal both injuries 8

Prognosis

• Strong evidence (level 1 or 2) for surgical management is lacking 9
• Choice of procedure depends on extent of tear, quality of ligament remnants, and reducibility of the joint 9
• Chronic scapholunate ligament injury can lead to carpal instability and degenerative arthritis if left untreated, with subsequent loss of function and disability 4