Courtesy: Dr. Ahlam Arnaout, MD, Paris France

Key Insight

Despite extensive research, there is no universally accepted optimal treatment, reflecting the complexity of wrist biomechanics

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Historical Understanding of SLI

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Focus on Scapholunate Interosseous Ligament (SLIL)

The SLIL was traditionally considered the primary stabilizer.

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Components of SLIL

• Dorsal portion — Strongest, main stabilizer
• Volar portion — Weaker, elastic
• Intermediate portion — Fibrocartilaginous, minimal role

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Natural Progression of Untreated Injury

• Scapholunate dissociation
• DISI deformity
• SLAC wrist arthritis

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Early Surgical Approaches

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1. Direct Ligament Repair

Techniques

• Open repair
• Transosseous sutures
• Anchor fixation

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Limitations

• Large surgical exposure
• Vascular disruption
• Anchor-related complications
• Poor long-term outcomes

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2. Tendon Reconstruction

Common Techniques

• Three-ligament tenodesis
• Brunelli procedure
• Dorsal capsulodesis

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Indications

• Irreparable SL ligament
• Reducible gap
• No arthritis

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Outcomes

• Good pain relief
• Variable functional results
• Limited long-term stability

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Key Limitation

 Tendons may not replicate:

• Ligament biomechanics
• Proprioceptive function

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Modern Concept: Scapholunate Complex

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Key Principle

 Stability depends on the entire scapholunate complex, not just the SL ligament

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Components

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Intrinsic Structure

• Scapholunate interosseous ligament

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Extrinsic Ligaments

• Dorsal intercarpal ligament (DIC)
• Dorsal capsulo-scapholunate septum (DCSS)
• Radioscaphocapitate ligament
• Long and short radiolunate ligaments
• Scaphotrapeziotrapezoid ligament

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Key Stabilizers

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Dorsal Capsulo-Scapholunate Septum (DCSS)

Role

• Secondary stabilizer
• Contains:
  • Blood supply
  • Mechanoreceptors

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Clinical Significance

• Injury — Dynamic instability, even with intact SL ligament

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Dorsal Intercarpal Ligament (DIC)

Role

• Major stabilizer of SL complex

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Key Finding

• Sectioning DIC — significant instability

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Role of Proprioception

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Concept

Wrist stability involves sensorimotor control

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Structures Containing Mechanoreceptors

• DCSS
• Dorsal capsule
• Extrinsic ligaments

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Dynamic Stabilizers

• Flexor carpi radialis (FCR)
• Forearm muscle reflexes
• Posterior interosseous nerve

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Modern Classification

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Gold Standard

Arthroscopic classification

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Geissler Classification

• Four stages based on arthroscopy

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EWAS Classification (0–4)

Represents:

• Dynamic instability
• Partial tear
• Complete tear
• Static instability

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Current Treatment Philosophy

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Modern Principle

 Treat scapholunate instability, not just the ligament

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Structures to Address

• Dorsal SL ligament
• DCSS
• DIC
• Extrinsic ligament complex

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Role of Wrist Arthroscopy

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Why It Is Gold Standard

• Dynamic assessment
• Accurate staging
• Guides treatment
• Minimizes tissue damage

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Modern Surgical Techniques

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1. Open Reconstruction

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ANAFAB Technique

• Hybrid synthetic tendon reconstruction

Targets

• SL ligament
• DCSS
• Extrinsic ligaments

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Limitations

• Extensive dissection
• Limited long-term data

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2. Arthroscopic Reconstruction Techniques

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PCO Box Technique

• Reconstructs dorsal + volar SL ligaments

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Corella Technique

• Fully arthroscopic
• Recreates SL ligaments

 Does not address extrinsic ligaments

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Smiley Suture Button

• Reconstructs:
  • DCSS
  • SL ligament
  • Extrinsic stabilizers

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3. Internal Brace (Gomez Technique)

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Key Features

• Arthroscopic
• No tendon graft
• Internal stabilization

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Options

Option A

• Stable bones
• Reconstructs SL + DCSS

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Option B

• Unstable scaphoid
• Adds DIC + STT ligament

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Option C

• Advanced instability
• Reconstructs all stabilizers

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4. Arthroscopic Dorsal Capsuloligamentous Repair (ADCLR)

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Concept

• Capsule acts as plate
• Ligament acts as bone

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Indications

• Dynamic instability
• Partial tears
• Reducible cases

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Procedure

• Arthroscopic evaluation
• Assess DCSS
• Midcarpal instability testing
• Suture capsule to ligament

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Structures Addressed

• Dorsal SL ligament
• DCSS
• Partial extrinsic support

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Outcomes

• ~800 cases reported
• Good:
  • Pain relief
  • ROM
  • Grip strength

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Return to Activity

• Work: ~9 weeks
• Athletes: return to same level

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Postoperative Protocol

• Immobilization: 6 weeks
• With K-wires: 8 weeks
• Rehab focuses on:
  • Proprioception
  • FCR strengthening

 Avoid early aggressive stretching

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Evidence-Based Treatment Algorithm (2023)

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Stage 1 (Dynamic)

• Immobilization (6 weeks)

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Stage 2–3 (Partial)

• ADCLR
• Arthroscopic pinning

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Stage 3C (Complete)

• Large ADCLR
• Reconstruction

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Stage 4 (Advanced)

• Arthroscopic/open reconstruction
• Salvage procedures

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Special Scenario: Distal Radius Fracture + SL Widening

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Early Stage (<3)

• Treat fracture only
   SL gap may heal

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Advanced Stage

• Arthroscopic stabilization required

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Advantages of Arthroscopic Surgery

• Minimal soft tissue damage
• Preserves vascularity
• Preserves proprioception
• Less stiffness

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Future Directions

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Ideal Procedure Should

• Be arthroscopic
• Address:
  • DCSS
  • SL ligament
  • DIC
• Preserve biomechanics and proprioception

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Current Reality

 No single technique meets all criteria yet

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Key Take-Home Messages

• SLI involves the entire scapholunate complex, not just SL ligament
• Arthroscopy is the gold standard for diagnosis and management
• Modern treatment focuses on:
  • Biomechanics
  • Proprioception
  • Multi-structure reconstruction
• ADCLR is highly promising for early instability