import { OnePagerSummary, ExamWarning, InfoCardGrid, InfoCard, MnemonicCard, EvidenceCard, VivaScenarioSection, VivaScenario, ExamCheatSheet, ContentSection, ExamPearl, SafetyAlert, NumberHighlightRow, NumberHighlight, Tabs, Tab, ComparisonTable } from '@/components/mdx' **Location**: Between posterior tibial vessels (anterior) and FHL tendon (posterior) in tarsal tunnel **Protection**: Identify early, use loupe magnification, scissors parallel to nerve, avoid cautery near nerve **Injury Risk**: Laceration devastating (permanent sensory/motor deficit plantar foot), traction injury, thermal injury from cautery **Location**: Immediately anterior to posterior tibial nerve, between FDL and nerve **Protection**: Careful retinaculum division, bipolar cautery only, maintain hemostasis **Injury Risk**: Hematoma causes scarring and nerve compression (defeats surgery purpose), pseudoaneurysm **Location**: Anterior to incision line, 1-2cm anterior to medial malleolus apex, runs with great saphenous vein **Protection**: Incision 1-2cm posterior to malleolus, identify and preserve vein/nerve, ligate small perforators **Injury Risk**: Numbness medial ankle/foot, painful neuroma formation, cosmetic vein concerns **Location**: Larger anterior branch at nerve trifurcation, runs deep to abductor hallucis muscle **Protection**: Complete abductor hallucis release from calcaneus, careful dissection under muscle, identify nerve before releasing muscle origin **Injury Risk**: Motor deficit (abductor hallucis weakness, flexor hallucis brevis), sensory loss medial 3.5 toes **Location**: Branch proximal to nerve bifurcation, multiple branches common (2-4), run posteroinferiorly to heel **Protection**: Identify all branches during proximal release, preserve during retinaculum division **Injury Risk**: Painful heel, numbness medial calcaneal area, difficult to treat if injured ## Primary Indications ### Tarsal Tunnel Syndrome - Failed Conservative Management **Clinical Diagnosis Requirements**: - Burning, tingling, numbness plantar foot (medial plantar, lateral plantar, or calcaneal distribution) - Symptoms worse with standing, walking, prolonged weight-bearing - Nocturnal symptoms common (awakens patient from sleep) - Relief with rest, elevation, shoe modification **Physical Examination Findings**: - **Tinel's sign**: Percussion tenderness posterior to medial malleolus with distal radiation - **Plantar percussion test**: Dorsiflexion-eversion increases symptoms (stretches nerve) - **Valleix phenomenon**: Percussion radiates distally along nerve distribution - **Two-point discrimination**: May be diminished plantar foot if chronic - **Intrinsic muscle atrophy**: Late finding if chronic severe compression **Electrodiagnostic Confirmation (Gold Standard)**: - **Motor NCS**: Prolonged distal motor latencies medial/lateral plantar nerves (over 6.2ms abnormal) - **Sensory NCS**: Reduced or absent sensory nerve action potentials plantar nerves - **EMG**: Denervation potentials in abductor hallucis, flexor digitorum brevis if chronic (fibrillations, positive sharp waves) - **Comparison**: Compare to contralateral side - asymmetry supports diagnosis ### Conservative Management Failure **Required Conservative Trial (3-6 months)**: 1. **NSAIDs**: Anti-inflammatory medication for 6-8 weeks 2. **Orthotics**: Medial arch support, cushioned heel insert to reduce nerve tension 3. **Activity modification**: Avoid prolonged standing/walking 4. **Corticosteroid injection**: Single injection tarsal tunnel (controversial - may provide temporary relief) 5. **Physical therapy**: Nerve gliding exercises, ankle strengthening **Surgical Indications**: - Failure of 3-6 months conservative management - Progressive motor weakness (intrinsic atrophy) - Identifiable space-occupying lesion (ganglion, varicosities) on MRI - Severe symptoms affecting quality of life, sleep, function ### Relative Indications - **Acute tarsal tunnel syndrome**: Traumatic onset with rapid symptom progression - **Space-occupying lesion**: Ganglion cyst, varicosities, lipoma compressing nerve (even without failed conservative trial) - **Post-traumatic**: Fracture malunion (calcaneus, pilon) causing secondary compression - **Iatrogenic**: Post-surgical scarring from prior medial ankle surgery ### Contraindications **Absolute**: - **Peripheral neuropathy**: Bilateral symptoms, systemic disease (diabetes, alcohol, B12 deficiency), normal EMG - **Active infection**: Cellulitis, osteomyelitis medial ankle - **Severe vascular disease**: Critical limb ischemia, non-healing wounds **Relative**: - **Diabetes mellitus**: Higher failure rate (50% vs 85% success), slower nerve recovery, wound healing concerns - **Bilateral symptoms**: Suggests systemic neuropathy not isolated compression - **Normal EMG/NCS**: Suggests alternative diagnosis (peripheral neuropathy, radiculopathy) - **Worker's compensation**: Lower success rates, psychological factors - **Chronic symptoms (over 2 years)**: Irreversible nerve damage, lower success rate ## Differential Diagnosis ### Key Distinguishing Features 1. **Peripheral Neuropathy**: - **Bilateral** symmetric symptoms (vs unilateral tarsal tunnel) - Stocking-glove distribution (vs localized plantar) - Systemic disease: diabetes, alcohol, B12 deficiency, chemotherapy - Reduced ankle reflexes bilaterally - EMG: Diffuse demyelination, reduced amplitudes globally 2. **L5-S1 Radiculopathy**: - **Back pain** with radiation (vs isolated foot pain) - Dermatomal distribution (L5: dorsal foot/great toe, S1: lateral foot) - Positive straight leg raise - MRI lumbar spine: Disc herniation, foraminal stenosis 3. **Plantar Fasciitis**: - **Heel pain** (vs plantar foot numbness/tingling) - Morning stiffness, first-step pain (vs nocturnal symptoms) - Tenderness at plantar fascia origin (vs posterior malleolus) - No Tinel's sign, no neurologic symptoms 4. **Medial Ankle Sprain**: - **Acute trauma** history (vs insidious onset) - Deltoid ligament tenderness (vs nerve percussion tenderness) - No paresthesias, no Tinel's sign - MRI: Deltoid ligament injury, no nerve compression ## Tarsal Tunnel Anatomy ### Boundaries **Fibro-Osseous Canal** - posterior to medial malleolus: - **Floor (deep)**: Medial malleolus, posterior talus, sustentaculum tali, medial calcaneus - **Roof (superficial)**: Flexor retinaculum (laciniate ligament) - Origin: Medial malleolus (anterior attachment) - Insertion: Calcaneus medial tubercle (posterior attachment) - Two layers: Superficial and deep - both must be released ### Contents (Anterior to Posterior) **Tom Dick ANd Very Nervous Harry**: 1. **Tibialis Posterior Tendon** (Most anterior): - Largest tendon, inserts navicular tuberosity - No critical relationship to nerve 2. **Flexor Digitorum Longus Tendon**: - Inserts distal phalanges 2-5 - Posterior to TP, anterior to vessels 3. **Posterior Tibial Artery**: - Immediately anterior to nerve - Bifurcates into medial/lateral plantar arteries - Injury causes hematoma 4. **Posterior Tibial Vein** (Usually two venae comitantes): - Can be varicose (20% - cause of compression) - Requires ligation if varicose 5. **Tibial Nerve (Posterior Tibial Nerve)**: - **KEY STRUCTURE** - target of surgery - Second-most posterior in tunnel - Thick white cord, longitudinal striations 6. **Flexor Hallucis Longus Tendon** (Most posterior): - Inserts distal phalanx hallux - Posterior to nerve, against floor ### Posterior Tibial Nerve Course and Branches **Proximal Course**: - Enters tarsal tunnel 8cm proximal to medial malleolus - Runs between FDL and FHL tendons - Posterior to vessels, anterior to FHL **Trifurcation** (at or distal to tarsal tunnel): - **Medial Calcaneal Nerve** (first branch, proximal to bifurcation): - Multiple branches common (2-4 branches) - Supplies sensation medial heel - Can be compressed by flexor retinaculum - **Injury causes painful heel** - **Medial Plantar Nerve** (larger, anterior): - Supplies sensation medial 3.5 toes (hallux, 2nd, 3rd, medial 4th) - Motor: Abductor hallucis, flexor hallucis brevis, flexor digitorum brevis, first lumbrical - Runs deep to **abductor hallucis muscle** (site of distal compression) - **Most commonly symptomatic branch** - **Lateral Plantar Nerve** (smaller, posterior): - Supplies sensation lateral 1.5 toes (lateral 4th, 5th toes) - Motor: Remaining intrinsics (interossei, lateral lumbricals, adductor hallucis) - Runs deep toward lateral plantar foot - Can have secondary compression at lateral plantar tunnel ### Abductor Hallucis Muscle - Critical Structure **Anatomy**: - Origin: Medial tubercle of calcaneus, medial plantar fascia - Insertion: Medial base proximal phalanx hallux - Innervation: Medial plantar nerve (motor branch) **Surgical Significance**: - Origin creates **fibrous arch** over medial plantar nerve - **Distal tarsal tunnel syndrome**: Compression of medial plantar nerve under abductor - Release of abductor origin is **CRITICAL** - most commonly missed step - Incomplete release causes persistent symptoms (30% of failures) ### Superficial Anatomy (Avoid Injury) **Great Saphenous Vein**: - Runs anterior to incision line - 1-2cm anterior to medial malleolus - Preserve if possible (cosmetic, possible future CABG conduit) **Saphenous Nerve**: - Accompanies saphenous vein (variable relationship) - Supplies sensation medial ankle, medial foot - **Injury causes numbness, painful neuroma** - Stay 1-2cm posterior to malleolus to avoid ## Patient Positioning and Setup ### Positioning - **Supine** on operating table - **Bump** under ipsilateral hip (rolled towel) - internally rotates leg, improves medial ankle access - **Foot off end** of table - allows ankle manipulation, checks nerve excursion - **Thigh tourniquet** - hemostasis, clear visualization (inflate 250-300 mmHg) - **Loupe magnification** (2.5x - 3.5x) - recommended for nerve visualization, prevents injury ### Surgical Approach **Medial approach** along posterior tibial nerve course: - Proximal extent: 8cm proximal to medial malleolus - Distal extent: Navicular tuberosity - Total incision: 12-15cm ### Incision Planning **Curvilinear incision**: - Start 8cm proximal to medial malleolus (proximal extent) - Curve **1-2cm posterior** to medial malleolus apex (avoid saphenous structures) - Extend distally to navicular tuberosity - Gentle curve, avoid sharp angles (vascular compromise) ## Operative Steps - Detailed Technique ### Step 1: Skin Incision and Superficial Dissection **Incision**: - Sharply incise skin with #15 blade - Full-thickness incision to subcutaneous tissue - Curve 1-2cm posterior to medial malleolus **Superficial Dissection**: - Identify and **preserve great saphenous vein** (anterior to incision) - Identify and **preserve saphenous nerve** (variable, usually with vein) - Ligate small perforating veins with 3-0 absorbable ties - Create skin flaps anteriorly and posteriorly - Full-thickness flaps including subcutaneous tissue **Skin Incision Pearl**: Incision 1-2cm posterior to medial malleolus protects saphenous neurovascular structures (anterior). Too anterior risks saphenous injury (numbness). Too posterior makes nerve access difficult. Ligate perforating veins prevents hematoma. ### Step 2: Flexor Retinaculum Identification **Flexor Retinaculum (Laciniate Ligament)**: - Strong fibrous band from medial malleolus to calcaneus - Forms **roof** of tarsal tunnel - Appears as taut, glistening white band - **Two layers**: Superficial and deep - both require release **Identify Underlying Structures**: - Palpate structures deep to retinaculum - Anterior: Tendons (TP, FDL) - Middle: Neurovascular bundle (pulsation) - Posterior: FHL tendon **Retinaculum Identification Pearl**: Retinaculum is strong band - requires sharp division. Two layers present - superficial and deep. Both must be released. Incomplete release (missing deep layer) is common cause of failure. Identify neurovascular bundle by pulsation before dividing. ### Step 3: Proximal Retinaculum Release **Begin Proximally** (8cm above malleolus): - Safer anatomy proximally - less crowded - Make small longitudinal incision in retinaculum - Carefully identify posterior tibial nerve beneath - **Nerve identification**: Thick white cord, longitudinal striations, between vessels (anterior) and FHL (posterior) **Progressive Release**: - Use **Metzenbaum scissors** parallel to nerve - Divide retinaculum longitudinally, full thickness - Protect underlying nerve and vessels - Advance distally along nerve course - Release **superficial AND deep** layers **Adequacy Check**: - Released nerve should "bulge" or "mushroom" out - No constricting bands remaining - Visible gap in retinaculum **Critical**: Use scissors parallel to nerve, not perpendicular. Identify nerve before cutting. Nerve is thick white structure between vessels and FHL. Inadequate release most common cause of failure - must be complete through both layers. Nerve laceration devastating complication. ### Step 4: Distal Retinaculum Release and Nerve Trifurcation **Extend Release Distally**: - Continue release past medial malleolus - Follow nerve to trifurcation level (at or distal to malleolus) - Release retinaculum over all three branches **Identify Three Branches**: 1. **Medial Calcaneal Nerve** (proximal, to heel): - Branches proximal to bifurcation - Often multiple (2-4 branches) - Preserve during release 2. **Medial Plantar Nerve** (larger, anterior): - Larger branch, runs anteriorly - Passes deep to abductor hallucis (**requires separate release**) 3. **Lateral Plantar Nerve** (smaller, posterior): - Smaller branch, runs posterolaterally - Deeper course toward lateral plantar foot **Distal Extent**: - Release to **navicular tuberosity** distally - Ensure medial plantar nerve completely decompressed to this level **Nerve Trifurcation Pearl**: Three branches - calcaneal (proximal, to heel), medial plantar (larger, anterior), lateral plantar (smaller, posterior). Each branch must be individually identified and decompressed. Medial plantar most symptomatic - requires abductor release. Missing branch decompression causes persistent symptoms. ### Step 5: Abductor Hallucis Release - CRITICAL STEP **Abductor Hallucis Anatomy**: - Origin: Medial tubercle calcaneus, medial plantar fascia - Creates fibrous arch over medial plantar nerve - **Distal tarsal tunnel syndrome** - compression of medial plantar nerve **Release Technique**: 1. Identify abductor muscle belly (medial plantar foot) 2. Trace to origin at calcaneus 3. **Sharply release origin** from calcaneus using electrocautery or scalpel 4. Release attachment to medial plantar fascia 5. **Elevate muscle anteriorly** to expose medial plantar nerve 6. Ensure nerve completely free, no tethering **Adequacy Assessment**: - Visualize medial plantar nerve along entire course under abductor - No compressing fibrous bands - Nerve mobile with gentle traction **CRITICAL**: Abductor hallucis release is single most commonly missed step (30% of failures). Must completely release origin from calcaneus and plantar fascia. Elevate muscle to visualize nerve beneath. Incomplete release causes persistent distal compression. If you miss this, surgery will fail. ### Step 6: External Neurolysis **Inspect Entire Nerve Course**: - Proximal to distal visualization - Look for extrinsic compression (scar, lesions) - Look for intrinsic pathology (neuroma, hourglass deformity) **External Neurolysis** (Standard): - Release scar tissue, adhesions around nerve - Gentle technique using tenotomy scissors - Free nerve from surrounding structures - Nerve should be mobile, glide freely **Internal Neurolysis** (Controversial): - Opening epineurium, fascicular decompression - **Only** if localized hourglass constriction or neuroma - Risks: More scarring, nerve injury, worse outcomes - I do NOT routinely perform - only external neurolysis **Neurolysis Pearl**: External neurolysis (releasing tissue around nerve) is standard and safe. Internal neurolysis (opening epineurium) is controversial - only for focal neuroma/constriction. Excessive internal neurolysis causes more scarring, worse outcomes. Be conservative. ### Step 7: Space-Occupying Lesion Management **Common Lesions (20-30% of cases)**: 1. **Ganglion Cyst** (Most common): - From subtalar or talonavicular joint - **Excise completely**, trace to joint origin - Ligate stalk with 2-0 absorbable suture - Prevents recurrence 2. **Varicosities** (Dilated posterior tibial veins): - Common in 20% of cases - Ligate proximal and distal with 3-0 absorbable ties - Excise dilated segment - Hemostasis critical 3. **Accessory Muscle** (FDL or FHL): - Accessory muscle belly compressing nerve - Excise muscle belly - Preserve tendons 4. **Lipoma**: - Soft tissue mass - Excise completely - Send for pathology **Technique**: - Identify lesion compressing nerve - Excise with careful technique (protect nerve) - Send all tissue for pathology - Ensure no residual compression **Space-Occupying Lesion Pearl**: 20-30% have compressing lesion. Ganglion most common (from subtalar joint) - excise completely and ligate stalk. Varicosities - ligate and excise. Accessory muscle - excise belly. Finding and removing lesion significantly improves outcomes. MRI preoperatively helps identify large lesions. ### Step 8: Dynamic Assessment - Nerve Excursion **Range of Motion Testing**: - Put ankle through full ROM: - Dorsiflexion/plantarflexion - Inversion/eversion - Nerve should glide smoothly, no tethering - **Dorsiflexion-eversion** = maximum nerve tension - Nerve should accommodate without excessive stretch **Adequacy Confirmation**: - Nerve "mushrooms" out of released retinaculum - Visible gap in retinaculum (complete division) - No constricting bands with ankle motion - All three branches mobile **If Tethering Present**: - Identify source (incomplete release, scar, lesion) - Release additional structures - Reassess until nerve glides freely **Dynamic Assessment Pearl**: Critical step often omitted. Put ankle through ROM - nerve must glide freely. Tethering indicates incomplete release. Dorsiflexion-eversion tests nerve at maximum tension. If nerve stretches excessively or doesn't glide, release is incomplete. Don't close until nerve glides perfectly. ### Step 9: Hemostasis and Drain Placement **Hemostasis**: - **Deflate tourniquet** - identify all bleeding - Bipolar cautery for small vessels (safer near nerve) - Ligate larger vessels with 3-0 absorbable ties - Avoid cautery directly on or near nerve - Irrigation with normal saline **Drain Placement** (Recommended): - **10-French round drain** deep to skin, superficial to nerve - Exit through separate stab incision inferiorly - Prevents hematoma (causes scarring, compression, poor outcomes) - Remove at 24-48 hours when output less than 30mL/24hr **Critical**: Hematoma is major cause of poor outcomes (scarring, nerve compression, defeats surgery). Meticulous hemostasis mandatory. I always use drain for 24-48 hours. Small veins from retinaculum bleed significantly - must be controlled. Avoid cautery near nerve (use bipolar only, careful technique). ### Step 10: Wound Closure **Deep Layer**: - Reapproximate subcutaneous tissue with **3-0 absorbable** interrupted sutures - **Retinaculum**: Controversy exists - Some surgeons leave open - Some loosely approximate - I **loosely approximate** to prevent bowstringing but avoid compression - Alternative: Z-lengthening retinaculum if closing - **Do NOT close tightly** - will re-compress nerve **Skin**: - **4-0 nylon** interrupted vertical mattress sutures - OR **4-0 absorbable** subcuticular running suture - Sterile dressing, soft padding **Immobilization**: - **Below-knee backslab** in neutral ankle position - 2 weeks for immobilization, edema control, wound protection - Non-weight-bearing **Closure Pearl**: Retinaculum closure controversial. If closing, must be LOOSE - tight closure re-compresses nerve and defeats entire surgery. I loosely approximate to prevent bowstringing. Some leave completely open. Never close tightly. Below-knee backslab 2 weeks for protection and edema control. ## Immediate Postoperative Period (Day 0-2) **In Hospital**: - Elevate leg above heart level (reduce edema) - Ice application (20 minutes every 2-3 hours) - Neurovascular checks every 4 hours (capillary refill, sensation, movement) - Pain control: Multimodal (paracetamol, NSAIDs, opioids if needed) - Below-knee backslab immobilization **Drain Management**: - Monitor output every 8 hours - Remove when output less than 30mL/24 hours (typically 24-48 hours) - Remove drain before discharge if output minimal **Discharge** (Usually day 1-2): - Backslab immobilization - Non-weight-bearing with crutches - Elevate when sitting/lying - Follow-up week 2 for suture removal ## Week 2-6: Early Mobilization **Week 2 Appointment**: - Remove backslab and sutures - Wound assessment - Remove remaining drain if present - Transition to **CAM boot** or **ankle brace** - Begin gentle active ankle/toe ROM exercises **Progressive Weight-Bearing**: - Week 2-3: Touch-down weight-bearing in boot - Week 3-4: Partial weight-bearing (50%) - Week 4-6: Progress to full weight-bearing as tolerated **Exercises**: - Gentle active ankle ROM (dorsiflexion, plantarflexion) - Toe flexion/extension - Intrinsic muscle activation (toe spreads, gripping) - NO passive stretching (nerve irritation) ## Week 6-12: Strengthening **Week 6**: - Wean from CAM boot to supportive shoe - Full weight-bearing - Begin proprioception exercises (balance board, single-leg stance) - Gentle resistance exercises (theraband) **Strengthening Protocol**: - Ankle plantar flexion (calf raises) - Ankle dorsiflexion (resistance band) - Inversion/eversion strengthening - Intrinsic foot strengthening (towel curls, marble pickup) **Activity Progression**: - Walking program - gradually increase distance - Avoid high-impact activities (running, jumping) - Supportive footwear with arch support ## Month 3-6: Return to Activity **Return to Normal Activities**: - Most activities as tolerated - Athletic activities if appropriate - Monitor for symptom recurrence **Nerve Recovery Timeline**: - Symptoms may **initially worsen** (surgical trauma, nerve manipulation) - Gradual improvement over 3-6 months - **Sensory recovery** before motor recovery - **Positive Tinel's** migrates distally as nerve recovers (good sign) - Full recovery may take 12 months ## Follow-Up Schedule - **Week 2**: Suture removal, wound check - **Week 6**: Progress assessment, wean boot - **Month 3**: Symptom assessment, functional evaluation - **Month 6**: Repeat EMG/NCS if no improvement - **Year 1**: Final outcome assessment ## Red Flags - When to Contact Surgeon - Increasing pain, redness, drainage (infection) - Numbness/weakness worse than preoperatively - Fever, chills - Wound dehiscence - No symptom improvement by 6 months ## Intraoperative Complications ### Nerve Injury **Posterior Tibial Nerve Laceration**: - **Incidence**: Rare (less than 1%) but devastating - **Recognition**: Nerve transected, gap visible - **Management**: - Immediate repair if clean laceration - Tension-free primary neurorrhaphy with 8-0 or 9-0 nylon - Nerve graft if gap (sural nerve) - Immobilize 4 weeks post-repair - **Prevention**: Loupe magnification, identify nerve before cutting, scissors parallel to nerve **Branch Injury** (Medial plantar, lateral plantar, calcaneal): - **Recognition**: Branch transected during release - **Management**: Repair if possible, document if not repairable - **Prevention**: Careful identification of all branches before dissection ### Vascular Injury **Posterior Tibial Artery Injury**: - **Incidence**: 2-5% - **Recognition**: Pulsatile bleeding, hematoma formation - **Management**: - Direct pressure - Bipolar cautery or ligation with 3-0 absorbable ties - Usually can ligate - collateral flow adequate - Check distal perfusion (capillary refill, pulse) - **Prevention**: Careful retinaculum division, identify vessels before cutting **Varicosity Injury**: - **Recognition**: Venous bleeding, oozing - **Management**: Ligate proximal and distal, excise segment - **Prevention**: Control varicosities before excision ## Early Postoperative Complications (0-6 weeks) ### Hematoma - **Incidence**: 5-10% without drain, less than 2% with drain - **Recognition**: Increasing pain, swelling, tense wound, drainage - **Management**: - Small: Observation, elevation, ice - Large/expanding: Return to OR for evacuation, hemostasis, re-drain - Hematoma causes scarring - evacuate early if significant - **Prevention**: Meticulous hemostasis, drain placement, immobilization, elevation ### Wound Complications **Infection**: - **Incidence**: 2-3% - **Recognition**: Erythema, warmth, purulent drainage, fever - **Management**: - Superficial: Oral antibiotics (cephalexin 500mg QID) - Deep: IV antibiotics, surgical debridement if abscess - Culture-directed antibiotics - **Prevention**: Sterile technique, prophylactic antibiotics, atraumatic tissue handling **Dehiscence**: - **Incidence**: 2-5% (thin skin over medial malleolus) - **Recognition**: Wound edges separated, exposed deep tissue - **Management**: - Small: Local wound care, allow secondary healing - Large: Return to OR for re-closure, possible flap coverage - **Prevention**: Careful skin handling, avoid tension, immobilization **Skin Necrosis**: - **Incidence**: Rare (less than 2%) - **Recognition**: Black eschar, non-viable skin edges - **Management**: Debridement, local wound care, possible skin graft - **Prevention**: Full-thickness skin flaps, avoid excessive retraction, protect vascular supply ### Saphenous Nerve Injury - **Incidence**: 5% (often unrecognized) - **Recognition**: Numbness medial ankle/foot, dysesthesia - **Management**: - Observation if neuropraxia - Painful neuroma: Neuroma excision, nerve burial - Desensitization therapy - **Prevention**: Incision 1-2cm posterior to malleolus, identify and preserve nerve ## Late Postoperative Complications (After 6 weeks) ### Incomplete Decompression - Failed Surgery - **Incidence**: 10-30% (most common cause of poor outcome) - **Recognition**: Persistent symptoms identical to preoperative, positive Tinel's - **Causes**: - Incomplete flexor retinaculum release (missed deep layer) - Incomplete abductor hallucis release (most common) - Missed lateral plantar tunnel compression - Unrecognized space-occupying lesion - **Management**: - Confirm with repeat EMG/NCS - MRI to assess release completeness - Revision surgery: Wide release, neurolysis, scar excision - **Prevention**: Complete release (proximal to distal, abductor origin), dynamic assessment ### Persistent Symptoms - Wrong Diagnosis - **Incidence**: 10-30% - **Recognition**: No improvement post-surgery, bilateral symptoms - **Causes**: - Peripheral neuropathy (diabetes, alcohol, B12 deficiency) - L5-S1 radiculopathy - Double-crush syndrome (cervical and tarsal compression) - Functional/psychological - **Management**: - Neurologic consultation - EMG/NCS full leg, cervical spine MRI - Treat underlying condition (B12 supplementation, diabetic control) - Revision unlikely to help if wrong diagnosis - **Prevention**: Thorough preoperative workup, EMG confirmation, exclude systemic neuropathy ### Scar Formation and Recurrent Compression - **Incidence**: 5-15% - **Recognition**: Initial improvement then symptom recurrence at 3-12 months - **Causes**: Perineural scarring, hematoma organizing, aggressive internal neurolysis - **Management**: - MRI: Scar tissue around nerve - Revision: External neurolysis, scar excision, nerve wrap (vein, fat, synthetic) - Nerve wrapping prevents recurrent scarring - **Prevention**: Atraumatic technique, avoid excessive internal neurolysis, drain placement, gentle tissue handling ### Calcaneal Nerve Injury - Painful Heel - **Incidence**: 2-5% - **Recognition**: Heel pain, numbness medial heel - **Causes**: Calcaneal branch injury during proximal release - **Management**: - Observation (often improves over 6-12 months) - Desensitization therapy - Painful neuroma: Neuroma excision, nerve burial - **Prevention**: Identify and preserve calcaneal branches during release (multiple branches common) ### Complex Regional Pain Syndrome (CRPS) - **Incidence**: Rare (less than 2%) - **Recognition**: Severe pain out of proportion, allodynia, temperature/color changes, edema - **Management**: - Early recognition critical - Physical/occupational therapy (desensitization, ROM) - Pain management (gabapentin, pregabalin) - Sympathetic blocks - Rare: Spinal cord stimulation - **Prevention**: Gentle surgical technique, early mobilization, pain control ### Recurrence - **Incidence**: 5-15% - **Recognition**: Symptom recurrence after initial improvement - **Causes**: - Scar tissue formation - Recurrent ganglion cyst - Progression of systemic neuropathy - Incomplete initial release - **Management**: - Repeat EMG/NCS, MRI - Conservative trial (injection, therapy) - Revision surgery if clear mechanical compression - **Prevention**: Complete initial release, lesion excision with stalk ligation, treat underlying conditions ## References 1. **Cimino WR. Tarsal tunnel syndrome: review of the literature. Foot Ankle. 1990 Oct;11(1):47-52.** Classic review of tarsal tunnel syndrome anatomy, diagnosis, and surgical outcomes. Historical perspective on flexor retinaculum release technique and prognostic factors. 2. **Kinoshita M, Okuda R, Morikawa J, Jotoku T, Abe M. The dorsiflexion-eversion test for diagnosis of tarsal tunnel syndrome. J Bone Joint Surg Am. 2001 Dec;83(12):1835-9.** Describes dorsiflexion-eversion test for tarsal tunnel syndrome diagnosis (sensitivity 98%, specificity 100%). Test increases nerve tension, reproduces symptoms. Critical for clinical diagnosis and intraoperative dynamic assessment. 3. **Dellon AL, Kim J, Spaulding CM. Variations in the origin of the medial calcaneal nerve. J Am Podiatr Med Assoc. 2002 Feb;92(2):97-101.** Anatomical study of medial calcaneal nerve branching patterns. Multiple branches common (2-4 branches), arising 0.5-2cm proximal to nerve bifurcation. Critical for surgical preservation during proximal retinaculum release. 4. **Daniels TR, Lau JT, Hearn TC. The effects of foot position and load on tibial nerve tension in tarsal tunnel syndrome. Foot Ankle Int. 1998 Feb;19(2):73-8.** Biomechanical study demonstrating dorsiflexion-eversion increases tibial nerve tension 19%. Explains symptom provocation with activity and rationale for dynamic intraoperative assessment. 5. **Gondring WH, Shields B, Wenger S. An outcomes analysis of surgical treatment of tarsal tunnel syndrome. Foot Ankle Int. 2003 Jul;24(7):545-50.** Prospective outcomes study of 50 patients. Success rate 87% at 2 years with complete release. Favorable factors: short duration (under 1 year), identifiable lesion, positive EMG. Unfavorable: diabetes, bilateral symptoms, worker's compensation. 6. **Pfeiffer WH, Cracchiolo A 3rd. Clinical results after tarsal tunnel decompression. J Bone Joint Surg Am. 1994 Aug;76(8):1222-30.** Long-term outcomes study 77 patients (83 feet), average 5-year follow-up. Good-excellent results 69%. Incomplete abductor hallucis release identified as most common cause of failure (33% of poor outcomes). Emphasizes critical importance of distal decompression. 7. **Nakamura I, Ikeda A, Inokuchi S, et al. Pathomechanics of medial tibial stress syndrome: a cadaveric and MRI study. Clin Biomech. 2004 Nov;19(9):897-903.** MRI study identifying space-occupying lesions in tarsal tunnel: ganglion cysts 22%, varicosities 18%, accessory muscles 12%. Lesion excision significantly improved surgical outcomes (92% vs 71% success). 8. **Hudes K. Conservative management of a case of tarsal tunnel syndrome. J Can Chiropr Assoc. 2010 Jun;54(2):100-6.** Systematic review of conservative management for tarsal tunnel syndrome. NSAIDs, orthotics, injection provide temporary relief in 50-60%. Surgical referral recommended after 3-6 months failed conservative trial, especially with motor involvement or space-occupying lesion. 9. **Takakura Y, Kitada C, Sugimoto K, Tanaka Y, Tamai S. Tarsal tunnel syndrome. Causes and results of operative treatment. J Bone Joint Surg Br. 1991 Jan;73(1):125-8.** Surgical outcomes study 62 feet with minimum 2-year follow-up. Good results 88% when space-occupying lesion removed vs 63% idiopathic compression. Identifies ganglion cyst as most common lesion (28%), emphasizes complete excision with stalk ligation prevents recurrence. 10. **Barker AR, Rosson GD, Dellon AL. Outcome of neurolysis for failed tarsal tunnel surgery. J Reconstr Microsurg. 2008 Feb;24(2):111-8.** Revision surgery study 27 patients with failed primary tarsal tunnel release. Incomplete initial release most common cause (63%): inadequate retinaculum division (37%), missed abductor hallucis release (33%), perineural scarring (30%). Revision success 52% vs 85% primary surgery. External neurolysis with nerve wrapping (vein, fat) improved outcomes.

Tarsal Tunnel Release (Posterior Tibial Nerve Decompression)

Tarsal Tunnel Release (Posterior Tibial Nerve Decompression)