Endoscopic Carpal Tunnel Release Dr David Hildreth , Houston, TX. - PDF document

With Thanks to Endoscopic Carpal Tunnel Release Dr David Hildreth , Houston, TX. Dr Stuart Kirkham MBBS FRACS FAOrthA Hand & Upper Limb Surgeon Sydney, Australia . CTS – epidemiology CTS – Definition : MN compression neuropathy “who gets CTS?” Majority of sufferers are idiopathic • – F,F,F,F,F,F,F ! Minority have an identifiable cause: • – Space occupying lesion “Carpal” = wrist RA, synovitis. • – Fluid retention disorders CRF, CCF, endocrine (oestrogen: peri-partum, OCP) , lymphoedema. • Hypothyroidism • – Diabetes – Peripheral neuropathies Alcohol, cis-platin, vincristine, vitamin disorders, etc. • – Vibrational tools (so called “V.A.S.”) The commonest entrapment Eg Jackhammer, motorbikes , power tools etc • neuropathy

CTS pathology Idiopathic CTS – aetiology • Either: • Fuchs et al – • Tunnel gets smaller (attachments : scaphoid, trapezium, HH & pisiform). – – biopsied tenosynovium from 177 wrists • Contents get bigger – = non inflammatory D • Mismatch in size ; nerve suffers first • SK personal view • “ multiplanar carpal chondral • Compressed nerve degeneration” MCCD – Macro : • hyper, hypo – aemia • decrease in size of • Thickened gritty FR/TCL. – Micro carpal tunnel . • Demyelination – slower conduction of AP’s • Axonal degeneration • Axonal fibrosis Multiplanar Carpal Chondral Clinical Findings Degeneration (MCCD) Dx is largely clinical & takes some experience: Hypothesis : Recognised variation in Dx accuracy between hand surgeons, orthopods, hand therapists, students, physios, nurses & GP’s & other allied. • Tunnel is reduced in 3D volume • Contents become compressed • History – Nocturnal, sleep, shakes, car, kitchen, clumsy • Excitable tissue (median N) suffers first. – Responds to splinting • Sensory symptoms precede motor, + – Duration worth noting. assoc electrical changes. • Physical – Derkan’s, Phalen’s , Tinel’s. • Path changes eg demyelination are reversible at first – Locates mechanical irritation of MN @ wrist. – Quite likely correlates with Px. • Later become irreversible , eg axonal • NCS fibrosis – I Ix on (a) malingerers/WC, (b) diagnostic dilemnas, (c) re-dos. • Symptoms may even subside in the later – Sensory : N=55m/s; 45 bad ; 35 severe. stages. – Motor : late changes. severe CTS disease.

Physical findings Non operative Rx • Splints Sensitivity Specificity – Good data , provides relief but cumbersome. Derkan’s compression test 0.87 0.90 • Steroids Phalen’s test 0.75 0.47 • Short term relief with high recurrence rates Tinel’s sign 0.60 0.67 BMC Fam Pract. 2010 Jul 29;11:54. Randomised controlled trial of local corticosteroid injections for carpal tunnel syndrome in general practice. Peters-Veluthamaningal C, Winters JC, Groenier KH, Meyboom-de Jong B Diagnosis is clinical. • • Not supported by Fuchs et al J Hand Surg Am. 1991 Jul;16(4):753-8. Synovial histology in carpal tunnel syndrome. Semmes-Weinstein 2-point sensory mapping has • Fuchs PC, Nathan PA, Myers LD. limited value in diagnosis or monitoring of CTS . • NSAID’s The likelihood of a correct diagnosis correlates with • • Rest/activity modification the experience of the examiner. Surgical Rx OCTR vs ECTR • More cost effective than a trial of Non-op-Rx • Single portal ECTR Avoids in NCS + proven cases of CTS. incision at Glabrous skin J Hand Surg Am. 2009 Sep;34(7):1193-200. The cost-effectiveness of nonsurgical versus surgical treatment for carpal tunnel syndrome. • ECTR associated with Pomerance J, Zurakowski D, Fine I. • OCTR – Less post op pain • ECTR • Less use of analgesics – Single portal –eg Agee/Microaire CTRS – Faster recovery times – Double Portal • In WC & non WC patients

OCTR before & after tourniquet release Movie : Open neurolysis ������������� ����������������� Open vs Endoscopic ��������������� ������������������ � ������������������� ���� � Glabrous skin Non- glabrous skin ��������� ������������������������������ Greater post op induration Less pain � ��������� Faster recovery (WC & non WC pts) ���������������������������� � ������������������������ �

Prior to TCL/FR Dr John Agee ; Sacramento CA division . Microaire Pty Ltd Single portal ECTR: • Mark 1 instruments c 1995 ?? • Mark 2 instruments c 1998 ?? Post TCL/FR division Surgical technique “The safe zone” The safe zone

Single portal ECTR technique The safe . Surgical goals : • The surface anatomy is only a rough guide. • 1. Completely Divide TCL (FR),distal to proximal . The blunt instruments are passed blind using • surface anatomy & palpation. 2. Avoid : SPA The endoscope is advanced under vision - only • • MN- Branch to 3 rd web space as far as the distal edge of the TCL. • Superficial palmar veins • the scalpel is deployed under endoscopic vision • which allows you to avoid the nerves and vessels. Do not cut what you cannot see ! • If you lose vision, convert to OCTR. Eg severe • tenosynovitis. Surface anatomy ; planning skin incision. Kaplan’s line safe zone surg technique Palmar veins are variable. Can bleed post op causing potential adhesions.

Surface anatomy ; planning skin incision. Kaplan’s Cardinal Line Finds : • Thenar motor br • Hook of hamate • Distal edge of the TCL (FR). PCBMN is most likely pranged during skin incision and not by the endoscope. Incision is ulnar to PL. The diagram exaggerates true position of PCBMN. Video: JS Video: Mrs NH

4 weeks 2 weeks Bruising is common 6 months 6 months

6 months Post op regime • Naropin ; & +/- Celestone . • Soft bandage , no slab or splint. • No hand therapy • Active ROM • Drive car on day 1 • RTW – Office : 3 days – Manual labour : 4 weeks. – Self employed pts : RTW 1-2 days. • ROS 2 wks • Only see again if having problems. Variations of thenar motor 3 phases of “ getting better ” after ECTR branch. All of these should 1. Nerve decompression be avoided by the suggested ECTR Immediate • single portal “I slept better that night & ever since” • technique. 2. Wound healing Measured in weeks I personally have • Skin, TCL wound, bruise, had nil iatrogenic • nerve lacerations. Gripping & leaning sore for ~ 3-4 weeks. • 3. Nerve regeneration The nerve most Slow; measured in 1-2 years. • likely to lac is the Cell bodies at DRG manufacture proteins ; axonal transport. CDN to the 3 rd web • Limited by : space , not the • (a) pre-op severity of CTS thenar motor br. – (b)Duration of CTS – (c) comorbidities. –

Variations in Arterial anatomy Ulnar nerve Variations 35% 4% 39% Problematic aa in up to 10% of pts. A : Riche-Cannieu anastamosis – motor fibres of UN & MN communicate at wrist. FPB supplied by UN in 77% cases. A>B, but not C : could pose problems during either B: communicating sensory brr between UN & ECTR or OCTR. MN at the palm. 5% 16% 1% C: variant lumbrical motor supply Variations in tendons – PL Variations in tendons –FCR PL is a highly variable m. Absent in 10% population Palmaris profundus (F) may pass through the Type D is the C tunnel & attach to the deep surface of palmar aponeurosis. only type likely to be relevant to CTS .

Abberant PL muscle Abberant PL muscle Mrs Marion B 45 yo F Feint blue discolouration pre op = m Outcomes •2002 •192 hands •Prospective RCT • 95-99% G/E results: multicenter •1 year f/u – Mild will often fully recover median n sensation – Mod some full, some partial – Severe usually partial ; will usually report less •ECTR : nocturnal sx •better functional •Less pain • Outcomes are probably determined by : •Less symptoms severity score – Pre op severity of CTS – Pre op duration of Sx •Shorter Return to – Comorbidities , ….ability for n regeneration work – Surgical avoidance of iatrogenic injury – Post op bleeding & adhesions *