Carpal Tunnel Release - Endoscopic Technique (Single Portal)

Indication. Symptomatic carpal tunnel syndrome (CTS) - numbness and tingling in the median distribution, nocturnal waking, thenar weakness if severe, a positive Phalen's test and Tinel's sign - confirmed electrodiagnostically (EMG/NCS showing moderate-to-severe median nerve slowing across the wrist), that has failed conservative management (a nocturnal wrist splint, activity modification, NSAIDs and at least one corticosteroid injection). The corticosteroid injection gives reliable short-term relief (around three months) but surgery is superior long-term. Assess suitability for the endoscopic route specifically. Endoscopic CTR trades a smaller scar and faster recovery for a restricted view and a learning curve, so it is a technique for correctly selected patients in correctly trained hands.

Consent specifically for the endoscopic-specific risks: an incomplete release rate of 2-8 percent (higher than open at 1-3 percent, and higher again in the learning curve), nerve injury 0.5-2 percent, and the possibility of intraoperative conversion to open (1-5 percent). Document that long-term outcomes are equivalent to open CTR. Counselling and contemporaneous consent documentation are essential in any medico-legal environment. Setup. Supine with the arm abducted 90 degrees on a hand table, an upper-arm tourniquet (250 mmHg, exsanguinate with an Esmarch bandage or elevation). The wrist is extended 20-30 degrees on a commercial holder or folded towels; the fingers are relaxed in natural cascade with NO traction; the forearm is fully supinated. Loupe magnification is recommended and a working monitor is positioned for the surgeon's direct viewing. Anaesthesia is most commonly a regional block (axillary or supraclavicular); wide-awake local anaesthesia no tourniquet (WALANT, 1 percent lidocaine with 1:100,000 epinephrine) is an alternative - the patient can move the fingers to demonstrate the release - though bleeding may obscure the endoscopic view.

The goal: divide the transverse carpal ligament (TCL) completely from its proximal to its distal edge under endoscopic vision, with the median nerve held safely on the ulnar side of the screen and the blade cutting radially away from it, stopping at the distal fat pad, then inspect for completeness before a splint-free closure. The portal and exposure are laid out in full below - they are the heart of the operation.

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Rehabilitation | Phase | Timing | Management | Milestones | |-------|--------|-----------|------------| | 1 | 0-48 hours | Soft dressing only, NO splint; elevate; begin finger/thumb active ROM hourly; ice 20 min on/off | Pain control, neurovascular checks | | 2 | Day 1 to 2 weeks | Remove bulky dressing for a simple adhesive bandage; keep dry until sutures out (7-10 days); light ADLs; start scar massage once epithelialised | Return to office/light work 7-14 days | | 3 | 2-6 weeks | Therapy putty and graded grip strengthening; moderate activities | Grip 50 percent of baseline by 2 weeks, 80 percent by 6 weeks | | 4 | 6-12 weeks | Heavy activities, manual labour, contact sports based on grip recovery | Grip 80-90 percent by 6 weeks, full by 12-16 weeks | | 5 | 3-12 months | Scar maturation; address any residual pillar pain | Final strength plateau by 4-6 months | Return to work depends on demand: office/sedentary 7-14 days (about 5-7 days earlier than open); light manual 2-3 weeks; moderate manual 3-6 weeks; heavy manual 6-12 weeks. Around 90-95 percent report significant symptom relief, with 85-90 percent satisfaction and 2-5 percent recurrence at 5-10 years (the same as open). Simple analgesia (paracetamol, a short opioid course) covers postoperative pain; an anti-staphylococcal antibiotic is first-line if infection occurs, guided by local antimicrobial policy. Liaise with the relevant workers-compensation insurer for a structured return-to-work plan where applicable. Complications

The condition. Carpal tunnel syndrome is compression of the median nerve beneath the transverse carpal ligament at the wrist. When it persists despite a splint and a corticosteroid injection, surgical division of the ligament is the definitive treatment. Endoscopic release divides the same ligament and decompresses the same nerve as open release - it simply does so through a smaller wrist incision under camera vision, in exchange for a restricted view and a learning curve. Applied anatomy for the endoscopic route. The TCL (flexor retinaculum) is a dense band 2-3 cm long and 2-3 mm thick, attaching radially to the scaphoid tubercle and trapezium ridge and ulnarly to the pisiform and hook of hamate. When fully divided it gaps 5-10 mm and its edges retract. The median nerve enters the tunnel radial to the centre and courses ulnarly; in the endoscopic view it must sit on the ulnar (left) side of the screen throughout. The tunnel also carries the nine digital flexor tendons (4 FDS, 4 FDP, FPL) ulnar to the nerve. The superficial palmar arch (chiefly the ulnar artery) lies 1-2 cm distal to the TCL; the palmar cutaneous branch leaves the median nerve 5-8 cm proximally and runs between PL and FCR. Relevant variants include a persistent median artery (about 10 percent), a bifid median nerve (1-3 percent), and anomalous lumbrical origins or accessory FDS bellies (2-3 percent) - all are reasons to choose open.

Single-portal versus two-portal. The single-portal (Agee) technique uses one proximal wrist incision with the blade and camera in one assembly; it cannot directly see the palmar cut surface of the TCL but has a shorter learning curve and no palmar incision, and is the most widely used route internationally. The two-portal (Chow) technique adds a distal palm portal so both sides of the TCL can be seen, at the cost of a palmar incision (more early palmar pain) and a higher superficial arch injury risk, with a longer learning curve. Meta-analyses show no significant difference in outcomes, complications or incomplete-release rates between the two - surgeon familiarity drives the choice.

Key evidence. The defining trial of this technique is the original Agee multicentre RCT (1992): a 10-centre study of 122 patients (147 hands) in which median return to work for single-affected-hand patients was 21.5 days earlier with the endoscopic device, with two reoperations (only one a true incomplete release) and two transient ulnar neurapraxias. The Vasiliadis Cochrane review (2014, 28 trials, 2586 hands) found equivalent long-term symptom relief and an equal major complication rate, with return to work about 8 days earlier after endoscopic (mean difference -8.1 days, 95 percent CI -14.3 to -1.9) but more transient nerve symptoms. The Scholten Cochrane review of surgical techniques (2007, 33 trials) found no alternative superior to standard open release and an earlier return to work with endoscopic (weighted mean difference -6 days, 95 percent CI -9 to -3). The Atroshi 5-year RCT confirmed durable equivalence in symptom severity, function, pillar-type pain and reoperation (3 per group). The consistent message - equivalent long-term outcomes and faster recovery, but a higher incomplete-release rate that falls with experience - is why strict patient selection, cutting to the distal fat pad, and meticulous re-inspection are the operation's safety spine, and why this is a perennial viva topic.