Patient must be NPO for at least 8 hours. Perform comprehensive pre-operative screening including CBC, coagulation profile, and ECG. Obtain informed surgical consent. Administer prophylactic intravenous antibiotics 30-60 minutes before skin incision. Mark the operative site and verify patient identification and surgical site through a formal time-out procedure.
Post-operative admission for 2-3 days for pain management and monitoring. Immobilization in a volar splint for the initial phase, transitioning to a cast for 6-8 weeks. Physical therapy initiated post-immobilization. Strict avoidance of heavy lifting for 3-4 months. Follow-up for wound inspection and serial radiographic evaluation to assess ligament stability and hardware placement.
Clinical Guide: Scapholunate Ligament Reconstruction (SLR)
1. Introduction and Overview
The scapholunate (SL) ligament is the primary stabilizer of the carpus, acting as the critical link between the scaphoid and the lunate bones. When this ligament is torn or chronically insufficient, the natural kinematics of the wrist are disrupted, leading to Scapholunate Advanced Collapse (SLAC) wrist.
Scapholunate Ligament Reconstruction (SLR) is a sophisticated orthopedic surgical intervention designed to restore the structural integrity of this joint. Unlike simple debridement, reconstruction involves the use of autologous tendon grafts to recreate the ligamentous tether, aiming to prevent the progressive arthritic degeneration that follows chronic instability. This guide provides an exhaustive clinical overview of the procedure, from patient selection to post-operative rehabilitation.
2. Technical Specifications and Mechanisms
The scapholunate interosseous ligament (SLIL) is a complex, C-shaped structure consisting of dorsal, proximal, and volar components. The dorsal portion is the most mechanically significant, providing the primary resistance to rotational forces.
The Biomechanics of Reconstruction
- The Goal: To recreate the dorsal SLIL tension band to stabilize the scaphoid against the lunate, preventing scaphoid flexion and lunate extension (DISI deformity—Dorsal Intercalated Segment Instability).
- Graft Selection: Typically, a slip of the Flexor Carpi Radialis (FCR) tendon or the Extensor Carpi Radialis Longus (ECRL) is utilized. The graft is passed through bone tunnels in the scaphoid and lunate to replicate the native anatomical insertion points.
- Tensioning: Achieving the correct tension is the "gold standard" challenge. Over-tensioning can lead to joint stiffness, while under-tensioning fails to provide the necessary rotational stability.
3. Clinical Indications and Usage
Indications for Surgery
Surgical intervention is indicated when non-operative management (splinting, anti-inflammatories, activity modification) has failed to control pain or when radiographic evidence suggests progressive instability.
| Indication | Clinical Criteria |
|---|---|
| Acute Injury | High-grade partial or complete tear, diagnosed within 6 weeks of injury. |
| Chronic Instability | Symptomatic "reducible" instability (ligament is attenuated but the joint remains salvageable). |
| Dynamic Instability | Painful clicking or snapping with wrist motion, confirmed by fluoroscopy/stress views. |
| Pre-Arthritic State | Evidence of SL widening on X-ray (Terry Thomas sign) without fixed arthritic changes. |
Contraindications
- Fixed SLAC Wrist: Once the scaphoid-lunate joint has developed advanced degenerative arthritis, reconstruction is no longer indicated; salvage procedures like proximal row carpectomy or wrist fusion are preferred.
- Severe Osteoporosis: Compromised bone quality makes secure anchor/tunnel placement unreliable.
- Active Infection: Systemic or localized soft tissue infection at the surgical site.
4. Pre-Operative Preparation
- Imaging Protocol:
- Standard Radiographs: PA, Lateral, and Scaphoid views to assess carpal height and SL gap.
- Stress Views: Clenched-fist PA views to demonstrate dynamic widening.
- MRI/Arthroscopy: Gold standard for assessing the integrity of the ligament components and ruling out cartilage damage.
- Patient Counseling: Patients must understand that wrist motion may be slightly restricted post-operatively and that "normal" pre-injury function is rarely 100% achievable in chronic cases.
- Anesthesia: Usually performed under regional (brachial plexus block) or general anesthesia with a pneumatic tourniquet.
5. The Surgical Procedure: A Step-by-Step Breakdown
Phase I: Exposure
A dorsal longitudinal incision is made over the radiocarpal joint. The extensor retinaculum is divided, and the third and fourth extensor compartments are elevated to expose the dorsal capsule. A T-shaped capsulotomy is performed to visualize the SL interval.
Phase II: Assessment and Debridement
The surgeon performs an arthroscopic or open inspection. If the cartilage is pristine, the reconstruction proceeds. Frayed ligament remnants are debrided to create a clean bed for healing.
Phase III: Graft Harvesting and Tunneling
- Harvest: A slip of the FCR tendon is harvested through a separate volar incision or proximal forearm incision, preserving its distal insertion.
- Tunneling: A 2.0 to 2.5 mm drill is used to create a transverse tunnel in the proximal pole of the scaphoid and the lunate.
- Passage: The graft is passed through the tunnels, effectively "tethering" the two bones together.
Phase IV: Fixation and Closure
The graft is secured using interference screws, suture anchors, or transosseous sutures. The capsule is meticulously closed to provide secondary support, and the skin is closed with non-absorbable sutures.
6. Post-Operative Recovery Protocol
The recovery process is divided into distinct phases to protect the graft during the biological incorporation phase.
- Phase 1 (Weeks 0–6): Immobilization. The wrist is placed in a thumb-spica splint or cast. No active range of motion (AROM).
- Phase 2 (Weeks 6–12): Transition to a removable orthosis. Gentle AROM is initiated under the guidance of a hand therapist. No heavy lifting or resistive exercises.
- Phase 3 (Months 3–6): Strengthening phase. Gradual introduction of progressive resistance exercises. Return to light activities.
- Phase 4 (Months 6+): Full return to contact sports or heavy manual labor, provided pain is absent and stability is confirmed.
7. Potential Complications
- Stiffness: The most common complication. Strict adherence to hand therapy is vital.
- Loss of Reduction: If the graft stretches out or the bone tunnels fail, the wrist may return to an unstable state.
- Hardware Irritation: Prominent anchors or screws may require secondary removal.
- CRPS (Complex Regional Pain Syndrome): A rare but debilitating neurovascular response to wrist surgery.
- Infection: Managed with standard antibiotic protocols and irrigation if necessary.
8. Alternative Treatments
| Procedure | Best For |
|---|---|
| Capsulodesis | Patients with mild instability where a full reconstruction is deemed excessive. |
| Proximal Row Carpectomy | Patients with early-stage SLAC arthritis. |
| Four-Corner Arthrodesis | Patients with advanced mid-carpal SLAC arthritis. |
| Wrist Denervation | Patients whose primary complaint is pain, and where motion is less of a priority. |
9. Frequently Asked Questions (FAQ)
1. How long does the surgery take?
Typically, the procedure lasts between 90 and 150 minutes, depending on the complexity of the graft harvesting.
2. Will I ever have 100% of my original wrist motion back?
It is unlikely. Most patients regain 70–80% of normal wrist range of motion.
3. Is this procedure done arthroscopically?
It can be, but "open" reconstruction is more common for complex cases to ensure accurate tunnel placement.
4. How long do I need to be off work?
Sedentary jobs may allow for return within 2 weeks. Manual labor may require 4–6 months of light-duty restrictions.
5. What is the success rate of this surgery?
Success is defined by pain reduction and improved stability. Most studies report 80–85% patient satisfaction in well-selected populations.
6. Does the graft ever "break"?
While the graft itself is strong, the primary risk is the biological integration into the bone tunnels.
7. Can I drive while in the cast?
Driving is strictly prohibited until the surgeon clears the patient, usually after the cast is removed and grip strength is sufficient for vehicle control.
8. What happens if the reconstruction fails?
Salvage options like wrist fusion or proximal row carpectomy become the next steps.
9. Is physical therapy mandatory?
Yes. Without skilled hand therapy, the risk of permanent joint stiffness is extremely high.
10. How do I know if I have a SL ligament injury?
Common symptoms include pain on the radial side of the wrist, a "clunk" or "pop" during rotation, and weakness in grip strength.
10. Clinical Conclusion
Scapholunate Ligament Reconstruction represents a major technical undertaking in hand surgery. While the procedure is demanding, it offers the only viable path to restoring natural carpal mechanics in patients with symptomatic, pre-arthritic instability. Success hinges on a triad of: precise surgical technique, appropriate patient selection, and a highly disciplined post-operative rehabilitation program. Clinicians must weigh the invasive nature of the surgery against the progressive natural history of untreated SL instability to provide the best possible long-term outcomes for their patients.