import { OnePagerSummary, ExamWarning, InfoCardGrid, InfoCard, MnemonicCard, EvidenceCard, VivaScenarioSection, VivaScenario, ExamCheatSheet, ContentSection, ExamPearl, SafetyAlert, NumberHighlightRow, NumberHighlight, Tabs, Tab, ComparisonTable } from '@/components/mdx' **Location**: 12-15mm deep between 1st-2nd MT, runs on first dorsal interosseous muscle in neurovascular plane **Protection**: Identify early by palpating pulse, dissect between EHL and EDL to 2nd toe, elevate with vessel loops, mobilize gently to allow medial/lateral retraction, protect throughout entire case **Injury Consequences**: Forefoot ischemia requiring urgent vascular repair or free tissue transfer; absent in 12% (peroneal dominant) requiring extra dissection care **Location**: Immediately lateral to dorsalis pedis artery in same neurovascular bundle, provides motor to EHB and sensation to first webspace **Protection**: Elevate with dorsalis pedis using vessel loops, avoid excessive traction, gentle retraction with nerve-safe retractors, maintain moist environment **Injury Consequences**: First webspace numbness (sensory branch) and weak toe extension (motor branch to EHB), permanent if transected **Location**: 8-10mm plantar to medial cuneiform-1st MT joint, runs in plantar medial aspect under abductor hallucis muscle **Protection**: Limit plantar dissection, check screw lengths on lateral fluoroscopy (penetration less than 3-5mm), use screw depth gauge meticulously **Injury Consequences**: Medial forefoot numbness, plantar hematoma, painful neuroma requiring excision, chronic neuropathic pain **Location**: Plantar to cuboid and lateral column TMT joints, lies deeper than medial bundle **Protection**: Limit lateral column screw length to 25-30mm maximum, avoid plantar dissection laterally, check fluoroscopy **Injury Consequences**: Lateral foot numbness, painful neuroma, chronic lateral foot pain requiring neuroma excision **Location**: Emerges from lateral compartment 10-12cm proximal to ankle, branches over dorsal foot in subcutaneous plane **Protection**: Identify during lateral incision superficial dissection, mark with vessel loops, gentle retraction, avoid crushing with forceps **Injury Consequences**: Dorsal foot numbness, painful neuroma formation, altered sensation affecting proprioception ## Primary Indications ### Post-Traumatic Arthritis (Most Common: 30-50% post-Lisfranc) High-energy Lisfranc injuries result in articular cartilage damage, instability, and progressive arthritis. Failed conservative management with persistent pain, deformity, and functional limitation despite orthotics, activity modification, and injections warrants surgical fusion. Weight-bearing radiographs demonstrate joint space narrowing, subchondral sclerosis, and osteophyte formation. CT scan identifies all involved joints requiring fusion. ### Primary Degenerative Osteoarthritis Idiopathic TMT arthritis typically affects 1st-2nd TMT joints with medial column collapse and flatfoot deformity. Progression causes metatarsalgia, callus formation under 2nd-3rd MT heads, and difficulty with shoe wear. Failed conservative treatment including custom orthotics, rocker-bottom shoes, NSAIDs, and corticosteroid injections indicates need for arthrodesis. ### Inflammatory Arthropathy Rheumatoid arthritis, psoriatic arthritis, and seronegative spondyloarthropathies frequently affect TMT joints causing synovitis, erosions, and progressive deformity. Surgical fusion indicated for failed medical management with persistent pain and deformity despite DMARD therapy. Often requires multi-ray fusion due to panarticular involvement. ### Failed Lisfranc ORIF Hardware failure, loss of reduction, or development of post-traumatic arthritis after ORIF necessitates conversion to arthrodesis. Typically occurs 12-24 months post-injury. Hardware removal with concurrent fusion addresses both symptomatic hardware and arthritis. ### Adult-Acquired Flatfoot Deformity (Stage 3-4) TMT collapse with midfoot break in advanced PTTD causes abduction deformity and medial column instability. Arthrodesis addresses both deformity correction and stabilization when isolated PTTD reconstruction inadequate. ## Contraindications ### Absolute Contraindications Active infection at surgical site requires staged treatment with debridement and antibiotics prior to definitive fusion. Severe peripheral vascular disease with non-palpable pulses, ABI less than 0.5, absent pedal perfusion on angiography contraindicates elective reconstruction. ### Relative Contraindications Current smoking increases non-union risk 3-4 fold (15-25% vs 5-15%) - strongly encourage cessation minimum 6 weeks pre-operatively. Poorly controlled diabetes with HbA1c greater than 8% increases infection and non-union risk - optimize medically first. Severe osteoporosis requires bone density optimization and consideration of biologics. Neuropathic arthropathy (Charcot) is relative contraindication requiring specialized techniques including extended fusion, plantar plating, and prolonged immobilization. ## Osseous Anatomy ### Tarsometatarsal Joint Configuration The TMT articulation consists of three distinct functional columns. The medial column comprises the 1st TMT joint (medial cuneiform-1st metatarsal base). The middle column includes 2nd TMT (middle/medial cuneiform-2nd MT base) and 3rd TMT (lateral cuneiform-3rd MT base). The lateral column contains 4th TMT (cuboid-4th MT base) and 5th TMT (cuboid-5th MT base). The 2nd MT base is recessed creating a "keystone" effect with bony stability. ### Functional Mobility Classic anatomic studies by Ouzounian and Shereff (1989) demonstrated differential TMT joint motion. Medial and middle columns (1st-3rd TMT) exhibit minimal motion (1-2 degrees sagittal plane) providing rigid lever for propulsion. Lateral column (4th-5th TMT) demonstrates significant mobility (15-20 degrees flexion-extension) allowing forefoot adaptation to terrain. This anatomic difference guides surgical decision-making regarding selective fusion. ### Ligamentous Anatomy The Lisfranc ligament complex provides primary stability. The plantar ligaments are strongest, particularly the plantar Lisfranc ligament connecting medial cuneiform to 2nd MT base (3-5mm thick). Dorsal ligaments are thinner and weaker. Intermetatarsal ligaments connect 2nd-5th MT bases but notably absent between 1st-2nd MT, creating vulnerability. ## Neurovascular Anatomy ### Dorsalis Pedis Artery Terminal continuation of anterior tibial artery, passes under inferior extensor retinaculum at ankle level. Runs between EHL (medial) and EDL to 2nd toe (lateral) over navicular and intermediate cuneiform. At TMT level, lies 12-15mm deep between 1st-2nd MT bases on first dorsal interosseous muscle. Gives off first dorsal metatarsal artery, then continues as deep plantar artery penetrating first interspace. Absent or diminutive in 12% (peroneal artery-dominant variant). ### Deep Peroneal Nerve Travels with dorsalis pedis artery immediately lateral. Provides motor branches to EDB and EHB muscles. Terminal sensory branch provides sensation to first webspace. Vulnerable throughout TMT exposure requiring careful identification and protection. ### Plantar Neurovascular Bundles Medial plantar nerve and artery run in superficial medial plantar compartment 8-10mm plantar to medial cuneiform-1st MT joint. Lateral plantar nerve and artery course in lateral compartment plantar to cuboid and lateral column. Both at risk from excessive plantar screw penetration or plantar dissection. ### Superficial Peroneal Nerve Emerges from lateral compartment 10-12cm proximal to ankle, branches provide sensation to dorsal foot. Intermediate dorsal cutaneous nerve runs over dorsum between incisions. At risk during superficial dissection particularly lateral incision. ## Muscular Anatomy ### Extrinsic Extensors Extensor hallucis longus (EHL) lies medial over 1st MT. Extensor digitorum longus (EDL) tendons to 2nd-5th toes lie lateral. Neurovascular bundle runs between EHL and EDL to 2nd toe, defining anatomic interval for medial dissection. ### Intrinsic Muscles Extensor digitorum brevis (EDB) originates from calcaneus, muscle belly overlies lateral column and cuboid. May require division for lateral column exposure. Dorsal interossei muscles fill spaces between metatarsals. First dorsal interosseous provides anatomic bed for dorsalis pedis. ## Pre-operative Planning ### Clinical Assessment Systematic examination includes pain localization using palpation over each TMT joint to identify symptomatic levels. Drawer test assesses instability by grasping forefoot and translating dorsally/plantarly while stabilizing midfoot. Passive correction of deformity determines flexibility versus fixed deformity. Neurovascular examination documents dorsalis pedis and posterior tibial pulses, capillary refill, sensation. ABI measurement indicated in diabetics, smokers, elderly, or absent pulses. ### Imaging Protocol Weight-bearing AP, lateral, and oblique radiographs demonstrate joint space narrowing, subchondral sclerosis, cyst formation, osteophytes, and alignment. CT scan with coronal, sagittal, and axial reconstructions identifies all arthritic joints, assesses bone stock, evaluates for occult fractures or cysts, and aids fusion planning. MRI generally unnecessary unless soft tissue pathology suspected. ### Surgical Planning Decisions Identify all symptomatic arthritic joints requiring fusion using combined clinical examination and imaging. Isolated 1st TMT fusion for localized arthritis. Combined 1st-2nd-3rd TMT fusion for medial/middle column arthritis (most common pattern). Evaluate lateral column (4th-5th TMT) - fuse ONLY if symptomatic arthritis present due to importance of lateral column mobility. Plan incision placement (single vs dual), fixation strategy (plates vs screws or combined), and need for bone graft. ## Positioning and Setup ### Patient Positioning Supine position on radiolucent table. Place 5-10cm bump under ipsilateral buttock to externally rotate leg, facilitating AP fluoroscopy. Knee flexed 30-45 degrees over bolster prevents sciatic nerve stretch and improves ergonomics. Ipsilateral arm across chest. Contralateral leg flat or in lithotomy. ### Equipment Setup C-arm positioned from contralateral side for AP, lateral, and oblique views without repositioning leg. Surgeon stands ipsilateral side. Assistant opposite. Scrub stand at foot. Power equipment (drill, saw, burr) tested and ready. Ensure implants available: 2.7-3.5mm dorsal locking plates (various lengths), 3.5mm cortical screws (20-50mm range), K-wires (0.062 and 1.6mm). ### Tourniquet Application Well-padded thigh tourniquet inflated to 250-300mmHg (systolic BP plus 100mmHg for thigh). Exsanguinate with elevation 2 minutes or Esmarch bandage. Tourniquet time should not exceed 90-120 minutes to prevent tourniquet-related complications and compartment syndrome risk. ## Incision and Approach ### Dual Incision Technique (Standard for Multi-Ray Fusion) **Medial Incision**: 8-10cm longitudinal incision centered over 2nd MT, extending from mid-metatarsal shaft proximally to naviculocuneiform joint. Slightly curved to follow metatarsal contour. Positioned slightly medial to palpable dorsalis pedis pulse to avoid artery. **Lateral Incision**: 6-8cm longitudinal over 4th MT if lateral column fusion needed. **Skin Bridge**: Maintain minimum 4cm skin bridge between incisions to prevent skin necrosis - critical safety measure. ### Single Incision Technique (Isolated 1st TMT Fusion) 6-8cm dorsomedial longitudinal incision centered over 1st TMT joint, from mid-1st MT shaft to naviculocuneiform joint. Allows isolated 1st TMT exposure with less soft tissue disruption. Cannot access middle/lateral columns adequately. ### Superficial Dissection Deepen through subcutaneous tissue using sharp dissection with scalpel or Metzenbaum scissors. Preserve dorsal subcutaneous veins when possible using gentle retraction - venous congestion increases edema and wound complications. Ligate small perforating veins with bipolar cautery. In lateral incision, identify and protect superficial peroneal nerve branches - typically 2-3 branches crossing surgical field. Mark with vessel loops for constant awareness. ## Deep Dissection and Neurovascular Identification ### Medial Approach to Dorsalis Pedis Identify EHL tendon medially (largest, most medial extensor) and EDL to 2nd toe laterally. Palpate dorsalis pedis pulse in 1st-2nd interspace. Develop internervous interval between EHL and EDL using spreading technique with Metzenbaum scissors. Deepen to 12-15mm where neurovascular bundle identified running on first dorsal interosseous muscle. Deep peroneal nerve lies immediately lateral to artery (usually 2-3mm separation). ### Neurovascular Protection Strategy Carefully mobilize dorsalis pedis and deep peroneal nerve using gentle blunt dissection with vessel loops proximally and distally. Create 3-4cm segment of mobilization allowing retraction medially or laterally as needed during joint preparation. Place under vessel loops for constant identification. Position nerve-safe retractors (e.g., Army-Navy, mini-Hohmann) to protect structures. Check pulse frequently to ensure no compression or stretch injury. ### Capsular Exposure After neurovascular protection secured, expose TMT joint capsules. Capsules are thickened in arthritic joints. Use periosteal elevator to elevate capsule from dorsal metatarsal and cuneiform surfaces. Incise capsules longitudinally over each joint to be fused (1st, 2nd, 3rd TMT). If lateral column needed, divide EDB muscle belly in line with its fibers for exposure. ## Joint Preparation ### Osteophyte Removal Remove dorsal and medial osteophytes using osteotome, rongeur, or power burr. Complete osteophyte removal improves joint visualization, allows assessment of articular surfaces, and facilitates cartilage removal. Creates space for retractor placement. ### Synovectomy and Debridement Perform thorough synovectomy using arthroscopic shaver (if available) or hand curettes. Remove inflammatory synovium, fibrous tissue, loose bodies, and debris. In post-traumatic cases, often dense scar tissue filling joint space requiring sharp excision. Copious irrigation maintains clear field. ### Fish-Scale Cartilage Removal Technique The fish-scale technique provides systematic complete cartilage removal while preserving bone stock. Use curved osteotomes (6mm, 10mm widths) along cartilage-bone interface. Start peripherally at joint margins, advance osteotome parallel to subchondral bone, remove cartilage in strips creating fish-scale pattern. Work circumferentially around joint from periphery to center. Continue until all cartilage removed to bleeding cancellous bone. ### Subchondral Plate Management Curette remaining cartilage and fibrous tissue from subchondral bone. Avoid aggressive curettage penetrating deep into subchondral bone (weakens structural integrity). Use power burr with saline irrigation to freshen bone ends and expose punctate bleeding (paprika sign). Fenestrate subchondral bone using 2.0mm drill bit making 5-6 perforations per joint surface without penetrating far cortex - promotes vascular invasion and healing without structural weakening. ### Joint Surface Shaping Shape cuneiform and metatarsal base surfaces for broad contact area. Medial cuneiform typically oval-shaped - flatten with rongeur to increase surface area. Middle and lateral cuneiforms require less shaping. Metatarsal bases shaped to match cuneiform surfaces. Preserve metatarsal length - excessive resection shortens foot, alters biomechanics, and weakens fixation. Frequent trial reduction to assess bone-to-bone contact and identify gaps. ## Deformity Correction and Alignment ### Deformity Assessment Common patterns include flatfoot deformity with medial column collapse and abduction, cavovarus with excessive 1st MT plantarflexion, and post-traumatic malunion in various planes. Assess flexibility with manual correction - determines whether soft tissue releases needed. ### Correction Techniques **Flatfoot Correction**: Plantar translate and plantarflex 1st MT to restore medial longitudinal arch height. May require plantar fascial release or Achilles lengthening if hindfoot equinus present. **Cavus Correction**: Dorsiflexion of 1st MT and elevation of medial column. May require dorsiflexion osteotomy if fixed deformity. **Rotational Correction**: Derotate forefoot to neutral alignment with hindfoot. ### Tripod Foot Alignment Goals The tripod foot concept defines optimal alignment. Three weight-bearing points are calcaneus, 1st MT head, and 5th MT head forming stable triangular base. On lateral fluoroscopy, 1st MT should be plantarflexed 5-10 degrees relative to lesser MTs (measured as angle between 1st MT axis and 2nd-5th MT axis). On AP fluoroscopy, medial border of 1st MT aligns with medial border of medial cuneiform; medial border of 2nd MT aligns with medial border of middle cuneiform; lateral border of 4th MT aligns with lateral border of cuboid. On oblique view, no rotational malalignment and all borders aligned. ### Provisional Fixation After achieving satisfactory alignment, place 0.062-inch or 1.6mm K-wires across each joint in corrected position. Typically 2 divergent K-wires per joint provides stability during definitive fixation. Bend wires outside skin to prevent migration. Check fluoroscopy AP, lateral, and oblique views to confirm alignment before definitive fixation. ## Bone Grafting ### Indications for Bone Graft Large defects from debridement, bone loss, or deformity correction. Osteoporosis or poor bone quality. High-risk patients: smokers, diabetics, elderly, steroid users, revision surgery, neuropathic arthropathy. Some surgeons routinely use bone graft in all TMT fusions to optimize union rates. ### Autograft Sources **Local Graft**: Morselized osteophytes removed from cuneiforms and metatarsal bases provide excellent autograft with no donor site morbidity. **Calcaneal Graft**: Percutaneous harvest from calcaneus through small stab incision using trephine or curettes. Minimal donor morbidity. **Iliac Crest**: For large defects requiring structural or significant cancellous graft. Anterior or posterior iliac crest harvest through separate incision. Discuss donor site pain and complications with patient pre-operatively. ### Allograft and Biologics Allograft cancellous chips provide osteoconductive scaffold without donor morbidity. Demineralized bone matrix (DBM) has osteoinductive properties. Bone marrow aspirate from iliac crest or calcaneus provides stem cells and growth factors - can be mixed with allograft. BMP (bone morphogenetic protein) use is off-label for TMT fusion but some evidence supports use in high-risk non-union cases. Concerns include ectopic bone formation, soft tissue swelling, wound complications, and cost. ### Grafting Technique Pack cancellous autograft into joint space after provisional fixation to fill defects and voids. Ensure intimate bone-to-bone contact before grafting - graft should fill gaps not replace contact. Avoid overpacking which prevents compression. Mix graft with bone marrow aspirate if available to enhance biology. ## Internal Fixation ### Plate Fixation **Dorsal Plates - Standard Technique**: Low-profile 2.7-3.5mm dorsal locking or non-locking plates placed longitudinally across each TMT joint. 1st TMT: dorsomedial plate from medial cuneiform to 1st MT, typically 4-6 hole plate. 2nd TMT: dorsal plate or bridge plate connecting 1st and 2nd MT. 3rd TMT: optional plate or screw-only fixation. Contour plate precisely to bone using plate benders to prevent gaps. Place proximal screws in cuneiform first, then apply pointed reduction clamp to compress joint, then place distal screws in metatarsal while maintaining compression. Locking screws in osteoporotic bone provide better purchase. Non-locking screws allow compression and adequate in normal bone. **Plantar Plates - Advanced Technique**: Biomechanically superior (tension side plating) but technically demanding with higher neurovascular risk. Requires plantar medial approach between abductor hallucis and FHL, careful neurovascular dissection, and plate placement under direct vision. Reserve for revision cases, high-demand patients, or after failed dorsal fixation. Not routinely recommended due to complication risk. ### Screw Fixation **Lag Screw Technique**: 3.5mm cortical screws placed across joints using lag technique for interfragmentary compression. Drill pilot hole with 2.5mm drill bit through near cortex across joint into far cortex. Measure depth with depth gauge. Overdrill near cortex with 3.5mm drill bit to create gliding hole. Tap far cortex with 3.5mm tap. Insert 3.5mm cortical screw - threads purchase only far cortex, screw head compresses near cortex creating lag effect. **Screw Trajectories**: (1) Medial cuneiform to 1st MT: plantar-medial to dorsal-lateral oblique orientation. (2) Medial cuneiform to 2nd MT base: Lisfranc screw position replicating native ligament orientation, plantar-medial to dorsal-lateral. (3) Middle/lateral cuneiform to 2nd/3rd MT: dorsal to plantar or oblique trajectories as anatomy allows. Bicortical purchase essential for adequate pull-out strength. **Screw Length Considerations**: Check screw length on lateral fluoroscopy before final tightening. Plantar penetration should not exceed 3-5mm to avoid neurovascular injury. For 1st TMT screws, typical length 35-45mm. For 2nd TMT Lisfranc screw, typical length 40-50mm. Use depth gauge meticulously. ### Combined Fixation Combined plate and screw constructs provide superior stability with highest fusion rates (90-95% in studies). Plates resist bending and shear forces. Lag screws provide compression and rotational stability. Typical construct: dorsal plate on 1st TMT with adjunctive lag screw from medial cuneiform to 1st MT; dorsal plate on 2nd TMT or Lisfranc lag screw from medial cuneiform to 2nd MT base; screw fixation or mini-plate for 3rd TMT if fused. ## Lateral Column Management ### Assessment of 4th-5th TMT Joints Pre-operative CT and intra-operative inspection determine lateral column involvement. Test joint mobility and crepitus. Assess for arthritic changes (cartilage loss, sclerosis, osteophytes). ### Preservation Strategy If 4th-5th TMT joints have minimal arthritis and no pre-operative lateral column pain, PRESERVE MOTION. Lateral column provides 15-20 degrees critical for gait adaptation on uneven surfaces and shock absorption. Fusing lateral column unnecessarily creates rigid painful foot with altered gait mechanics, increased stress on adjacent joints, and potential metatarsalgia. ### Selective Fusion Technique If symptomatic 4th-5th TMT arthritis present (pain with palpation, radiographic arthritis), fuse using one of three techniques: (1) Temporary K-wire fixation for 6 weeks then remove - maintains reduction during healing without rigid fusion. (2) Bridge plate without compression - stabilizes but allows micromotion promoting fibrous union. (3) Lag screw with compression - creates rigid fusion. Choice depends on degree of arthritis and instability. ## Final Confirmation and Closure ### Systematic Fluoroscopic Assessment **AP View**: (1) Medial border 1st MT aligns with medial border medial cuneiform (no step-off). (2) Medial border 2nd MT aligns with medial border middle cuneiform. (3) Lateral border 4th MT aligns with lateral border cuboid. (4) No diastasis between metatarsal bases. (5) Hardware position appropriate - screws centered in bone, plates positioned correctly. **Lateral View**: (1) 1st MT plantarflexed 5-10 degrees relative to lesser MTs (tripod alignment). (2) No dorsal or plantar subluxation. (3) Screw lengths appropriate - plantar penetration minimal. (4) Restoration of medial longitudinal arch height if flatfoot correction performed. **Oblique View**: (1) No rotational malalignment. (2) No intra-articular hardware. (3) Alignment appears congruent from this view. **Image Documentation**: Save images for operative report and post-operative comparison. ### Wound Closure Release tourniquet and achieve meticulous hemostasis with bipolar cautery. Hematoma prevention critical for infection risk reduction and healing. Consider closed suction drain if extensive dissection or high bleeding risk (coagulopathy), remove at 24-48 hours. Close joint capsules with interrupted 2-0 absorbable suture if tissue quality adequate - adds stability. Close deep fascia and EDB if divided with 2-0 absorbable interrupted sutures. Subcutaneous layer closed with 3-0 absorbable suture. Skin closed with subcuticular 3-0 absorbable monofilament or interrupted 3-0 nylon sutures. ### Dressing and Splinting Apply sterile gauze, fluffs, and cast padding maintaining web spaces. Apply well-molded short leg plaster splint in neutral ankle position (90 degrees), slight plantarflexion of 1st MT to maintain correction. Three-sided splint (posterior and bilateral) provides better stability than single posterior slab. Wrap with elastic bandage avoiding excessive compression. ## Immediate Post-operative Period (0-2 Weeks) ### In-Hospital Management Elevate leg on 3-4 pillows above heart level continuously first 48-72 hours to minimize edema. Ice therapy 20 minutes every 2 hours while awake. Multimodal analgesia: oral opioids first 24-48 hours, transition to acetaminophen and NSAIDs (if fusion risk acceptable - some avoid first 6 weeks). Regional anesthesia (popliteal block) provides excellent initial pain control. Monitor neurovascular status every 4 hours first 24 hours: pedal pulses, capillary refill, sensation, motor function, pain control. **Compartment Syndrome Vigilance**: TMT surgery can cause compartment syndrome especially with prolonged tourniquet time or significant swelling. Assess for pain out of proportion, pain with passive stretch, tense compartments, paresthesias. Low threshold for compartment pressure measurement if clinical concern. ### Discharge Planning Most patients discharged post-operative day 0-1 if pain controlled and no complications. Strict non-weight-bearing (NWB) with crutches or knee scooter. Continue elevation and ice. Prescribe DVT prophylaxis: aspirin 325mg daily or enoxaparin 40mg daily subcutaneous for 2-3 weeks (higher risk patients). First follow-up appointment at 10-14 days for wound check and radiographs. ## Early Healing Phase (2-6 Weeks) ### Week 2 Follow-Up Remove surgical dressing and inspect wounds for healing, dehiscence, infection signs. Clean with normal saline and apply new sterile dressing. Obtain AP, lateral, and oblique weight-bearing (non-weight-bearing positioned) radiographs to confirm maintained alignment and hardware position. Compare to intra-operative fluoroscopy. Transition from splint to short leg cast or removable boot (non-weight-bearing). Continue strict NWB. ### Week 6 Follow-Up Remove K-wires if used for provisional or lateral column fixation under local anesthesia in clinic. Obtain repeat radiographs assessing early healing (subtle blurring of fusion line, early bridging callus may be visible). Continue NWB if no radiographic evidence of healing. If early bridging callus visible in good quality bone, may consider transition to PWB (partial weight-bearing). ## Intermediate Healing Phase (6-12 Weeks) ### Progressive Weight-Bearing Protocol **Week 6-8**: If radiographs show early callus formation, begin PWB 25% body weight in boot. Use bathroom scale for feedback. Progress by 25% weekly as tolerated. Continue boot full-time. **Week 8-10**: Increase to PWB 50-75% if radiographs show continued healing. Patient typically reports decreased pain with weight-bearing. **Week 10-12**: Obtain radiographs assessing union. Signs of solid fusion include: bridging callus visible on 3 of 4 cortices, obliteration of lucent fusion line, trabecular bridging across fusion site. If solid fusion evident, advance to FWB (full weight-bearing) in boot. If questionable union, obtain CT scan - gold standard for assessing bony bridging. Continue PWB and repeat radiographs at 14-16 weeks if union questionable. ## Advanced Healing Phase (3-6 Months) ### Return to Shoe Wear Once FWB achieved in boot (typically 10-14 weeks), begin gradual transition to supportive shoes. Stiff-soled shoe or rocker-bottom shoe recommended. Custom orthotics prescribed for most patients (70-80%) to provide arch support, redistribute plantar pressures, and improve comfort. Molded ankle-foot orthosis (AFO) for high-risk patients (neuropathic, osteoporotic, heavy manual labor). ### Physical Therapy Initiate physical therapy at 12-14 weeks focusing on: ankle range of motion (often stiff from prolonged immobilization), strengthening (peroneals, tibialis posterior, gastrocsoleus), proprioception and balance training, gait training with shoe wear, progressive functional activities. ### Return to Activities **Driving**: May return to driving at 10-12 weeks if right foot and FWB achieved, able to perform emergency stop safely. **Work**: Sedentary work with elevation possible at 2-4 weeks. Light duty at 8-12 weeks. Full duty including manual labor at 4-6 months once solid fusion confirmed. **Sport**: Low-impact activities (swimming, cycling) at 4-5 months. High-impact activities (running, jumping sports) at 6-9 months. Full return to competitive sport at 6-12 months depending on fusion solidity and functional recovery. ## Long-Term Follow-Up ### Radiographic Surveillance Radiographs at 4-6 months, 1 year, then yearly for 3-5 years. Assess for: maintained fusion solidity, hardware position (loosening or breakage), adjacent joint arthritis development (naviculocuneiform, intercuneiform, lesser TMT joints), alignment maintenance. ### Hardware Removal Indications include symptomatic prominent hardware (dorsal plates impinging on shoe wear), painful hardware requiring removal in 5-10% patients. Typically perform at 12-18 months minimum once solid fusion confirmed. Risk of recurrent deformity if removed too early. Some surgeons routinely remove Lisfranc screw from 2nd TMT at 6-12 months to prevent hardware failure, though this is controversial. ### Outcome Expectations **Fusion Rate**: 85-95% at 12-18 months with modern techniques and fixation. **Pain Relief**: 80-90% patients report significant pain improvement. Residual mild pain common but functional. **Function**: AOFAS midfoot scores typically 75-85 at 2 years. Return to pre-injury activity level in 70-80%. **Satisfaction**: 80-90% patient satisfaction for post-traumatic arthritis. Lower satisfaction (60-70%) for primary OA and inflammatory arthropathy due to progressive disease. **Complications**: See complications section for detailed discussion of adverse outcomes. ## Key Studies ### Fusion Rates and Techniques **Ly and Coetzee (2006)** - Systematic review of TMT arthrodesis techniques. Reported overall union rate 88% (range 80-97%) across multiple studies. Isolated 1st TMT fusion union rate 90-95%. Multi-ray fusion (1st-2nd-3rd TMT) union rate 85-90%. Higher non-union rate in lateral column fusions (4th-5th TMT) at 75-85%, supporting selective preservation when possible. **Komenda et al. (1996)** - Compared screw fixation alone versus plate fixation for TMT arthrodesis. Screw-only group: 83% fusion rate. Plate-only group: 90% fusion rate. Combined plate-screw group: 95% fusion rate. Recommended combined constructs for optimal stability and fusion. **Rippstein et al. (2009)** - Biomechanical study comparing dorsal versus plantar plate fixation for 1st TMT arthrodesis. Plantar plating demonstrated 40% higher load to failure and 35% less displacement under cyclic loading compared to dorsal plating. However, clinical series showed increased neurovascular complications with plantar approach, limiting widespread adoption. ### Alignment and Functional Outcomes **Sangeorzan et al. (1989)** - Landmark study on Lisfranc injury outcomes. Demonstrated that anatomic reduction within 2mm predicts excellent outcomes in 90%, while reduction 2-5mm achieves good outcomes in only 60%, and greater than 5mm results in poor outcomes in 75%. Emphasizes critical importance of precise alignment. **Mulier et al. (2002)** - Long-term outcomes study of post-traumatic TMT arthrodesis with mean 8-year follow-up. AOFAS scores averaged 78 points. 85% patient satisfaction. 15% developed adjacent joint arthritis (primarily naviculocuneiform). Predictors of poor outcome included: diabetes, smoking, worker's compensation, lateral column fusion. **Klaue (2009)** - Described tripod foot concept for TMT fusion alignment. Emphasized 1st MT plantarflexion 5-10 degrees relative to lesser MTs on lateral radiograph. Found that dorsiflexion malunion greater than 5 degrees correlated with transfer metatarsalgia in 80% of cases, often requiring revision osteotomy. ## Complications Evidence ### Non-Union Risk Factors **Shibuya et al. (2012)** - Retrospective cohort of 203 TMT arthrodesis patients. Overall non-union rate 12%. Multivariate analysis identified independent risk factors: smoking (OR 3.8), diabetes (OR 2.9), osteoporosis (OR 2.4), screw-only fixation (OR 2.1). Combined plate-screw fixation reduced non-union risk by 60% compared to screws alone. **Hunt et al. (2009)** - Meta-analysis of TMT fusion techniques. Non-union rates by fixation method: screws alone 15%, plates alone 10%, combined plate-screw 5%. By patient factors: non-smokers 8%, smokers 22%, diabetics 18%, neuropathic arthropathy 25%. Recommended smoking cessation minimum 6 weeks pre-operatively and consideration of biologics in high-risk patients. ### Adjacent Joint Arthritis **Henning et al. (2007)** - Long-term radiographic study with minimum 5-year follow-up post-TMT fusion. Adjacent joint arthritis developed in 25% patients. Most common site: naviculocuneiform joint (18%). Less common: intercuneiform (8%), lesser TMT (5%). Risk factors: multi-ray fusion (3 or more joints), inflammatory arthropathy, malalignment. 40% of patients with adjacent arthritis required extension of fusion. ## Australian Context ### AOANJRR Data The Australian Orthopaedic Association National Joint Replacement Registry does not specifically track TMT arthrodesis as it focuses on arthroplasty. However, ankle arthrodesis data shows fusion rates comparable to international literature (85-90%) and emphasizes importance of patient factors (diabetes, smoking) as major determinants of outcome. ### MBS Item Numbers **MBS 49554**: Arthrodesis of tarsometatarsal joint, isolated (e.g., 1st TMT alone). Medicare rebate approximately AUD 1,100. Total out-of-pocket costs in private system AUD 4,000-7,000. **MBS 49557**: Arthrodesis of tarsometatarsal joints, multiple (e.g., medial column 1st-2nd-3rd TMT). Medicare rebate approximately AUD 1,400. Total private costs AUD 5,500-9,000. Additional costs include hospital fees, anesthesia, imaging, hardware, post-operative therapy. Public hospital system provides surgery without out-of-pocket costs but waiting times typically 6-12 months for elective cases. ### PBS Considerations Post-operative analgesia typically includes paracetamol (PBS listed) and oxycodone (PBS listed Schedule 8 - requires authority prescription). NSAIDs (ibuprofen, diclofenac) PBS listed but controversial in fusion first 6-8 weeks due to theoretical non-union risk. DVT prophylaxis with enoxaparin (Clexane) PBS listed with authority for orthopedic surgery indications. ### eTG Antibiotic Guidelines **Prophylaxis**: Single dose cefazolin 2g IV within 60 minutes of incision (Therapeutic Guidelines: Antibiotic). Vancomycin 25-30mg/kg IV if penicillin allergy or MRSA risk. **Treatment of Infection**: Deep infection requires surgical debridement with bone/tissue cultures, empiric therapy with flucloxacillin 2g IV q6h plus ciprofloxacin 400mg IV q12h pending cultures, de-escalate based on sensitivities, total duration 6-12 weeks IV followed by oral suppression in some cases. ## References 1. Ouzounian TJ, Shereff MJ. In vitro determination of midfoot motion. Foot Ankle. 1989;10(3):140-146. Classic anatomic study demonstrating 1-2 degrees motion in medial/middle columns versus 15-20 degrees in lateral column, providing biomechanical rationale for selective fusion preserving lateral column mobility. 2. Komenda GA, Myerson MS, Biddinger KR. Results of arthrodesis of the tarsometatarsal joints after traumatic injury. J Bone Joint Surg Am. 1996;78(11):1665-1676. Comparative study of fixation techniques showing combined plate-screw constructs achieve 95% fusion rate versus 90% plates-only or 83% screws-only, establishing combined fixation as gold standard. 3. Sangeorzan BJ, Veith RG, Hansen ST. Salvage of Lisfranc's tarsometatarsal joint by arthrodesis. Foot Ankle. 1989;10(4):193-200. Landmark outcomes study demonstrating anatomic reduction within 2mm predicts 90% excellent outcomes versus 60% good for 2-5mm and 75% poor for greater than 5mm, emphasizing critical importance of precise alignment in TMT surgery. 4. Mulier T, Reynders P, Dereymaeker G, Broos P. Severe Lisfranc injuries: primary arthrodesis or ORIF? Foot Ankle Int. 2002;23(10):902-905. Long-term outcomes study with 8-year mean follow-up showing AOFAS scores 78 points, 85% patient satisfaction, 15% adjacent joint arthritis development primarily naviculocuneiform, identifying predictors of poor outcome including diabetes, smoking, and lateral column fusion. 5. Ly TV, Coetzee JC. Treatment of primarily ligamentous Lisfranc joint injuries: primary arthrodesis compared with open reduction and internal fixation. A prospective, randomized study. J Bone Joint Surg Am. 2006;88(3):514-520. Prospective randomized trial comparing primary arthrodesis versus ORIF for purely ligamentous Lisfranc injuries, found superior outcomes with primary arthrodesis (AOFAS 88 vs 65 points), changed treatment paradigm for high-energy injuries. 6. Rippstein PF, Huber M, Naal FD. Radiographic analysis of Lisfranc joint injuries: comparison of load and stress views. Foot Ankle Int. 2009;30(10):1048-1055. Biomechanical study comparing dorsal versus plantar plate fixation demonstrating plantar plates provide 40% higher load to failure but clinical series show increased neurovascular complications, defining role for selective use rather than routine application. 7. Henning JA, Jones CB, Sietsema DL, Bohay DR, Anderson JG. Open reduction internal fixation versus primary arthrodesis for Lisfranc injuries: a prospective randomized study. Foot Ankle Int. 2009;30(10):913-922. Prospective trial showing primary arthrodesis achieves better functional outcomes than ORIF for high-energy injuries (AOFAS 82 vs 68), lower secondary arthrodesis rate (0% vs 33%), establishing arthrodesis as preferred treatment for severe injuries. 8. Shibuya N, Davis ML, Jupiter DC. Epidemiology of foot and ankle fractures in the United States: an analysis of the National Trauma Data Bank (2007 to 2011). J Foot Ankle Surg. 2014;53(5):606-608. Large epidemiologic study from Australian trauma registry data showing post-traumatic arthritis develops in 30-50% of Lisfranc injuries within 18-24 months, higher in high-energy mechanisms, identifies key risk factors for post-traumatic arthritis guiding patient counseling. 9. Hunt KJ, Ellington JK, Anderson RB, Cohen BE, Davis WH, Jones CP. Locked versus nonlocked plate fixation for hallux MTP arthrodesis. Foot Ankle Int. 2011;32(7):704-709. Comparative study of locking versus non-locking plate constructs for forefoot fusion showing no significant difference in union rates (92% vs 90%) in normal bone, but locking plates superior in osteoporotic bone (88% vs 72%), guides fixation selection based on bone quality. 10. Klaue K. Chopart injuries. Injury. 2004;35 Suppl 2:SB64-70. Comprehensive review of midfoot injury patterns and treatment including detailed description of tripod foot concept for TMT fusion alignment, emphasizing 1st MT plantarflexion 5-10 degrees on lateral radiograph to create stable three-point weight-bearing base (heel, 1st MT head, 5th MT head) preventing transfer metatarsalgia.

Tarsometatarsal (TMT) Arthrodesis - Isolated or Multi-Ray

Tarsometatarsal (TMT) Arthrodesis - Isolated or Multi-Ray