Treatment of Scapholunate Ligament Tear with Widening and Increased Angle
For scapholunate ligament tears with widened scapholunate interval and increased scapholunate angle (indicating static instability), surgical reconstruction is required—specifically, the SwiveLock technique (SWT) demonstrates superior biomechanical outcomes compared to traditional three-ligament tenodesis or Mark-Henry techniques, though acute injuries within 4-6 weeks should undergo direct ligament repair with bone anchor fixation.
Acute vs. Chronic Injury Determines Treatment Path
The critical decision point is timing from injury:
Acute Injuries (< 4-6 weeks)
- Direct ligament repair with bone anchor fixation is the treatment of choice 1, 2
- Open reduction with minianchor (MITEK) reinsertion achieves 88% excellent or good functional outcomes at 32-month follow-up 1
- Early arthroscopic diagnosis within this window is mandatory, as proper ligament repair must occur within 4-6 weeks after trauma 2
- Your patient's widened interval and increased scapholunate angle indicate complete ligament disruption requiring surgical intervention
Chronic Injuries (> 4-6 weeks)
Since your patient has established static instability (widened interval + increased angle), reconstruction rather than repair is indicated:
The SwiveLock technique is biomechanically superior 3:
- Most effectively reduces scapholunate distance widening
- Only technique that normalizes scapholunate angle to match intact wrists
- Addresses both scaphoid flexion deformity AND lunate extension deformity
- Less technically complex than traditional methods, reducing operative time and complication risk from multiple incisions and transosseous tunnels
Why Traditional Approaches Fall Short
Direct ligament repair with capsulodesis fails in static instability 4:
- Only 2 of 17 patients achieved excellent/good clinical outcomes
- Failed to maintain carpal alignment (average scapholunate angle returned from corrected 47° to 72°)
- Did not provide consistent pain relief
- This poor outcome data is from 1998 but remains relevant for understanding why reconstruction is needed over simple repair in established instability
The three-ligament tenodesis (3LT) and Mark-Henry technique (MHT) have limitations 3:
- 3LT reconstructs only dorsal ligament, providing insufficient stability
- MHT adds volar reconstruction but is technically complex
- Neither addresses rotational deformities as effectively as SWT
Critical Pitfalls to Avoid
Do not attempt conservative treatment when radiographic evidence shows:
- Scapholunate interval widening > 2mm (adult standard)
- Increased scapholunate angle (normal ~47°)
- These findings indicate complete ligament disruption with static instability 5
Conservative treatment only works for partial tears without dissociation 5. Your patient's radiographic findings exclude this option.
Assess secondary stabilizers before surgery 6, 5:
- Evaluate extrinsic ligaments (DIC, LRL, RSC, DRC, STT)
- 44% of scapholunate injuries have accompanying extrinsic ligament damage 5
- This influences surgical planning and prognosis
Surgical Timing Urgency
Operate as soon as possible to prevent progression to scapholunate advanced collapse (SLAC) wrist 2:
- Isolated scapholunate ligament injury progresses to abnormal joint mechanics
- Leads to degenerative cartilage changes
- Treatment aims to arrest this degenerative process by restoring ligament continuity and normalizing carpal kinematics