import { OnePagerSummary, ExamWarning, InfoCardGrid, InfoCard, MnemonicCard, EvidenceCard, VivaScenarioSection, VivaScenario, ExamCheatSheet, ContentSection, ExamPearl, SafetyAlert, NumberHighlightRow, NumberHighlight, Tabs, Tab, ComparisonTable } from '@/components/mdx' **Location**: Runs between EHL and EDL tendons at ankle level, 2-3cm distal to talonavicular joint on dorsal midfoot **Protection Strategy**: Early identification after dorsal skin incision, careful retraction during tendon division, preserve adventitia, avoid electrocautery within 5mm, maintain visualization throughout dorsal dissection **Location**: Branches from posterior tibial artery/nerve 1cm distal to medial malleolus, runs 15-20mm from medial plantar border, primary supply to plantar flap **Protection Strategy**: Dissect superficial to neurovascular plane during medial approach, preserve all plantar soft tissue thickness, identify and protect before TP tendon division, maintain flap perfusion checks **Location**: Accompanies lateral plantar nerve lateral to FDL, gives calcaneal branches for heel sensation, runs deep to plantar aponeurosis **Protection Strategy**: Lateral dissection stays superficial to deep fascia, protect during peroneal tendon division, preserve calcaneal branches, maintain lateral flap thickness **Location**: Talar head (talonavicular joint) and anterior/middle facets of talus, will become exposed weight-bearing surface if arthrodesis not performed **Protection Strategy**: Careful capsular dissection to avoid gouging cartilage, smooth bone edges only (do not violate subchondral bone if preserving joint), consider arthrodesis to prevent arthrosis **Location**: Runs with dorsalis pedis artery between EHL and EDL, provides sensation to 1st web space, motor to EDB **Protection Strategy**: Identify with dorsalis pedis artery, gentle retraction only, avoid traction injury during joint exposure, divide sharply if necessary (motor loss acceptable, sensory loss problematic) ### Indications **Absolute Indications:** - Severe irreparable forefoot trauma with viable hindfoot - Diabetic forefoot gangrene/osteomyelitis with intact hindfoot perfusion - Malignant tumor of forefoot requiring negative margins - Failed multiple ray amputations with non-functional forefoot remnant - Chronic forefoot osteomyelitis unresponsive to medical/surgical management **Relative Indications:** - Severe Charcot forefoot deformity with irreparable midfoot collapse - Congenital forefoot deformity requiring reconstruction - Extensive soft tissue loss of forefoot with exposed bone - Peripheral vascular disease (PVD) when more distal amputation inadequate **Contraindications:** - Inadequate perfusion (TCPO2 less than 30mmHg, ABI less than 0.5) - Active hindfoot infection/osteomyelitis - Ischemic heel or Achilles region - Severe PVD requiring higher-level amputation - Patient non-ambulatory (consider BKA for prosthetic fitting) - Psychiatric/cognitive inability to cooperate with rehabilitation ### Evidence Base ### Australian Context - **PBS**: No specific listings for Chopart amputation medications - **Medicare MBS**: Item 50312 (midtarsal amputation) - complex procedure requiring detailed documentation - **eTG Antibiotic Guidelines**: Prophylaxis - cephazolin 2g IV pre-incision (or vancomycin if MRSA risk); therapeutic for diabetic infection - piperacillin-tazobactam 4.5g IV q8h - **AOANJRR**: Not applicable (arthroplasty registry) - **Australian epidemiology**: Diabetic foot complications account for 60% of Chopart amputations, increasing Indigenous population burden ### Surgical Anatomy **Transverse Tarsal Joint (Chopart Joint):** - Talonavicular joint (medial): Ball-and-socket, allows inversion/eversion - Calcaneocuboid joint (lateral): Modified saddle joint, more restricted motion - Joints function together as midtarsal joint complex - Preservation requires intact talus and calcaneus **Vascular Anatomy:** - **Dorsalis pedis artery**: Continuation of anterior tibial, runs between EHL/EDL, supplies dorsal skin - **Medial plantar artery**: Larger branch of posterior tibial, primary supply to plantar flap - **Lateral plantar artery**: Smaller branch, gives calcaneal branches, anastomoses with medial - **Perfusion requirement**: TCPO2 greater than 30mmHg, ABI greater than 0.5 for healing **Nerve Anatomy:** - **Medial plantar nerve**: Sensory to medial plantar skin (weight-bearing area), CRITICAL to preserve - **Lateral plantar nerve**: Sensory to lateral plantar skin, motor to intrinsics - **Deep peroneal nerve**: Runs with dorsalis pedis, 1st web space sensation - **Sural nerve**: Lateral border sensation **Muscle/Tendon Anatomy:** - **Lost with amputation**: TA, EHL, EDL (dorsiflexors), intrinsic foot muscles, FHL, FDL (distal) - **Retained**: Achilles (gastrocsoleus), TP, peroneus longus/brevis (proximal) - **Imbalance**: Achilles overpowers lost dorsiflexors causing equinus ### Biomechanics **Muscle Imbalance:** - Normal: Dorsiflexors (TA, EDL, EHL) balance Achilles plantarflexion force - Post-Chopart: Achilles unopposed causing progressive equinus contracture - Result: 30-50% equinus deformity rate without prevention **Weight Distribution:** - Normal foot: 50% hindfoot, 50% forefoot through metatarsal heads - Chopart: 100% weight on talus/calcaneus residual surfaces - Risk: Pressure ulceration if insensate or bony prominences present **Prosthetic Biomechanics:** - Short lever arm compared to Syme's/BKA - Equinus deformity prevents neutral foot position in prosthesis - AFO required in 80% to maintain alignment ### Primary Technique: Long Plantar Flap (Racquet Incision) **Standard Approach (Most Common):** - Transverse dorsal incision across talonavicular/calcaneocuboid joints - Extended medially/laterally to plantar midfoot - Plantar incision curves distally to distal forefoot/metatarsal heads - Long plantar flap rotates dorsally for coverage - Short dorsal flap discarded or trimmed minimally **Advantages:** - Sensate plantar skin for weight-bearing surface - Robust vascular supply (medial/lateral plantar arteries) - Thick padding from plantar fat and aponeurosis - Natural durability of plantar skin **Disadvantages:** - Scar on dorsal/plantar junction (prone to breakdown) - Requires excellent perfusion to heal - Risk of flap necrosis if vascular injury ### Alternative Technique: Sagittal (Medial/Lateral) Flaps **Technique:** - Medial and lateral sagittal flaps - Equal flap lengths - Less common approach **Indications:** - Dorsal/plantar tissue loss precluding racquet design - Specific vascular anatomy favoring sagittal vessels **Disadvantages:** - Non-plantar skin on weight-bearing surface (inferior durability) - Higher ulceration risk - Less sensate coverage ### Equinus Prevention Strategies **1. Achilles Lengthening (Most Common):** - Z-plasty or percutaneous triple-hemisection - Performed at index procedure - Risk: Over-lengthening causes calcaneus gait **2. Tendon Transfers:** - Anchor TA, EDL, EHL tendons to talar neck - Provides active dorsiflexion force - Technically demanding, limited evidence **3. Talocalcaneal Arthrodesis:** - Fuse talus to calcaneus at index procedure - Creates stable platform, prevents equinus - Increases surgery time, nonunion risk 10-15% - Many surgeons prefer this approach **4. Aggressive Postoperative Management:** - Serial casting to maintain neutral position - Long-term AFO use - Early detection and correction if develops ### Step 1: Vascular Assessment & Planning **CRITICAL first step - determines amputation feasibility:** - Palpate dorsalis pedis and posterior tibial pulses - Measure TCPO2 (transcutaneous oxygen pressure): MUST be greater than 30mmHg for healing - Calculate ankle-brachial index (ABI): MUST be greater than 0.5 - Assess skin quality, capillary refill, temperature - If marginal perfusion: consider vascular surgery consultation for revascularization first **Plan flap dimensions:** - Plantar flap must extend to distal forefoot (metatarsal head level) for adequate length - Measure distance from planned transverse tarsal cut to dorsum - flap must reach without tension - Mark talonavicular and calcaneocuboid joint positions (fluoroscopy helpful) **Exam Key**: "Chopart preserves the ankle joint and talus/calcaneus. Before proceeding, I MUST confirm adequate perfusion - palpable pulses, TCPO2 greater than 30mmHg, and ABI greater than 0.5. Inadequate perfusion is a contraindication requiring higher-level amputation. I plan a long plantar flap extending to the distal forefoot to ensure tension-free dorsal coverage." - Inadequate vascular assessment leads to flap failure and revision to higher level - Short plantar flap causes tension, necrosis, and wound breakdown - Wrong level selection (should consider Syme's/BKA if perfusion marginal) ### Step 2: Positioning, Preparation, and Flap Marking **Patient Positioning:** - Supine with ipsilateral hip bump (30 degrees internal rotation) - Thigh tourniquet applied (inflate to 250-300mmHg for lower extremity) - Affected foot off end of table or on radiolucent support - Prep from tourniquet to toes **Racquet Incision Marking:** - **Transverse dorsal limb**: Across talonavicular and calcaneocuboid joints (palpate, fluoroscopy confirm) - **Medial extension**: Curve distally along medial midfoot to plantar surface - **Lateral extension**: Curve distally along lateral midfoot to plantar surface - **Plantar limb**: Transverse or gently curved incision at distal forefoot/metatarsal head level - Plantar flap is LONG (6-8cm from transverse tarsal joint), dorsal flap is SHORT (1-2cm) **Exam Key**: "I use a 'racquet incision' with a long plantar flap and short dorsal flap. The plantar skin is sensate, thick, and durable - ideal for the weight-bearing surface. The flap must extend far enough distally to reach the dorsum without any tension." - Short plantar flap is the most common technical error causing flap tension and necrosis - Incision too proximal risks injury to medial/lateral plantar neurovascular bundles - Incision too distal wastes viable forefoot tissue ### Step 3: Dorsal Dissection and Neurovascular Identification **Incise dorsal skin and subcutaneous tissue:** - Sharply incise along marked transverse dorsal incision - Deepen through subcutaneous fat to extensor retinaculum **Identify and protect dorsalis pedis artery:** - Runs between EHL (medial) and EDL (lateral) tendons - Palpate pulsations, visualize artery and accompanying deep peroneal nerve - CRITICAL: This vessel supplies dorsal skin - injury causes skin necrosis **Divide extensor tendons:** - Identify TA (most medial), EHL, EDL, peroneus tertius (if present) - Tag tendons with sutures for later use (can anchor to talus to prevent equinus) - Divide tendons sharply under direct vision - Retract proximally to expose talonavicular and calcaneocuboid joint capsules **Exam Key**: "I identify the dorsalis pedis artery running between EHL and EDL tendons. I protect this vessel meticulously as it supplies the dorsal skin. I tag the extensor tendons with sutures - these can be anchored to the talar neck later to provide dorsiflexion force and help prevent equinus deformity." - Dorsalis pedis injury causes dorsal skin ischemia and wound breakdown - Deep peroneal nerve traction injury (usually not critical as motor loss to EDB only) - Inadequate joint capsule exposure leads to difficulty with disarticulation ### Step 4: Medial Dissection and Plantar Nerve Preservation **Extend medial limb of incision:** - Curve distally along medial border of foot - Deepen through skin and subcutaneous tissue **Identify tibialis posterior tendon:** - Large tendon inserting on navicular tuberosity (medial midfoot prominence) - Palpate, visualize insertion - Divide tendon sharply but DO NOT retract immediately **CRITICAL: Identify and protect medial plantar neurovascular bundle:** - Runs 15-20mm from medial plantar border, deep to skin/fat but superficial to flexor tendons - Branches from posterior tibial artery/nerve 1cm distal to medial malleolus - **PRIMARY blood supply to plantar flap** - **PRIMARY sensation to weight-bearing surface** - Dissect superficial to this bundle, preserve within plantar flap thickness **Exam Key**: "The medial plantar neurovascular bundle is CRITICAL to the success of this operation. It provides the blood supply and protective sensation to the plantar flap. I dissect carefully, staying superficial to this bundle and preserving it within the full thickness of the plantar flap. Injury here is catastrophic - the stump becomes insensate and prone to ulceration." - Medial plantar nerve injury creates insensate stump (major functional failure) - Medial plantar artery injury causes flap ischemia and necrosis - Inadvertent TP tendon avulsion from navicular causes bleeding ### Step 5: Lateral Dissection and Sural Nerve Protection **Extend lateral limb of incision:** - Curve distally along lateral border of foot - Deepen through skin and subcutaneous tissue **Identify peroneal tendons:** - Peroneus brevis: Inserts on 5th metatarsal base (palpate) - Peroneus longus: Crosses plantar to 1st cuneiform - Divide both tendons sharply **Protect sural nerve:** - Runs along lateral border of foot, supplies lateral foot sensation - Identify and protect or divide sharply under direct vision (if necessary) **Identify lateral plantar neurovascular bundle:** - Accompanies lateral plantar nerve - Gives calcaneal branches supplying heel sensation - Preserve within plantar flap **Exam Key**: "I protect the sural nerve laterally to preserve lateral foot sensation, though this is less critical than plantar nerves. The lateral plantar neurovascular bundle is preserved within the plantar flap. The calcaneal branches from this bundle provide heel sensation." - Sural nerve injury causes lateral foot numbness (usually well-tolerated) - Lateral plantar nerve injury reduces plantar sensation - Peroneal artery injury (if present) can compromise lateral flap perfusion ### Step 6: Joint Capsule Opening and Disarticulation **Expose transverse tarsal joint:** - Identify talonavicular joint capsule medially - Identify calcaneocuboid joint capsule laterally - These two joints together form the transverse tarsal (Chopart) joint **Open joint capsules:** - Sharply incise talonavicular capsule circumferentially - Sharply incise calcaneocuboid capsule circumferentially - Plantarflex foot to open joints **Disarticulate forefoot:** - Carefully disarticulate navicular from talar head - Disarticulate cuboid from calcaneus - Remove navicular, cuboid, and entire forefoot en bloc - PRESERVE talus and calcaneus articular surfaces (avoid gouging cartilage) **Exam Key**: "Chopart amputation is a true disarticulation through the transverse tarsal joint - the talonavicular joint medially and calcaneocuboid joint laterally. I carefully preserve the articular cartilage of the talus and calcaneus. These surfaces can be preserved for motion or prepared for arthrodesis depending on my equinus prevention strategy." - Damage to talar head cartilage causes arthritis if joint preserved - Calcaneal articular surface damage complicates arthrodesis if planned - Incomplete bone removal leaves sharp prominences causing ulceration ### Step 7: Plantar Flap Development **Develop full-thickness plantar flap:** - Incise plantar skin at marked distal level (metatarsal heads) - Include ALL plantar structures in flap: - Skin - Subcutaneous fat - Plantar aponeurosis - Medial and lateral plantar neurovascular bundles (CRITICAL) - Divide FHL and FDL tendons distally (preserve proximal stumps) **Assess flap perfusion:** - Release tourniquet briefly to assess flap bleeding - Ensure brisk capillary refill - Doppler medial and lateral plantar arteries to confirm flow **Trim excess tissue:** - Remove excess fat to allow flap to lie flat without bulk - DO NOT thin the flap excessively - maintain vascular plexus and nerve protection **Exam Key**: "The plantar flap contains sensate plantar skin with intact medial and lateral plantar nerves for protective sensation. I preserve the full thickness of the flap including the plantar fat and aponeurosis for durable padding. The flap must be long enough to reach the dorsum without any tension - tension is the main cause of flap failure." - Thin flap lacks padding and is prone to ulceration - Nerve injury during flap development creates insensate stump - Vascular injury causes flap necrosis - Short flap creates tension leading to ischemia and dehiscence ### Step 8: Equinus Prevention - Achilles Lengthening **CRITICAL STEP - addresses the major complication of Chopart:** Equinus deformity occurs in 30-50% due to Achilles overpull after loss of dorsiflexors. MUST address at index surgery. **Option 1A: Achilles Z-plasty Lengthening (Preferred by many):** - Make 3cm longitudinal incision over Achilles (posteromedial) - Perform Z-plasty: proximal medial hemisection, distal lateral hemisection, 3-4cm apart - Dorsiflex foot to neutral, sutures ends with knee flexed (reduces tension) - Risk: Over-lengthening causes calcaneus gait **Option 1B: Percutaneous Triple Hemisection:** - Three 1cm stab incisions over Achilles - Proximal medial, middle lateral, distal medial hemisections - Dorsiflex to neutral, allow healing with lengthening **Examiner will ask: "How much lengthening?"** - Lengthen until foot rests at NEUTRAL (90 degrees) with knee extended - Typically requires 2-3cm of lengthening - Check with foot held in dorsiflexion - should have no resistance **Exam Key**: "The MAJOR complication of Chopart amputation is equinus deformity, occurring in 30-50% of cases. This happens because the Achilles tendon overpowers the lost dorsiflexors. I address this at the index surgery with Achilles lengthening - either Z-plasty or percutaneous triple hemisection. I lengthen until the foot rests at neutral with no resistance to dorsiflexion." - Failure to address equinus leads to progressive plantarflexion contracture - Over-lengthening causes calcaneus gait and weak push-off - Under-lengthening fails to prevent equinus development ### Step 9: Equinus Prevention - Tendon Transfer (Optional) **Alternative/adjunct to Achilles lengthening:** **Anchor extensor tendons to talus:** - Use tagged TA, EDL, and EHL tendons (from Step 3) - Drill holes in talar neck (dorsal to articular surface) - Pass tendons through drill holes or anchor with suture anchors - Suture tendons under tension with foot at neutral - Provides active dorsiflexion force to balance Achilles **Advantages:** - Maintains some active dorsiflexion - Theoretically better balance than lengthening alone **Disadvantages:** - Technically demanding - Limited evidence of effectiveness - Tendons may stretch over time **Exam Key**: "Some surgeons anchor the extensor tendons to the talar neck to provide a dorsiflexion force balancing the Achilles. I drill holes in the talar neck and pass the TA, EDL, and EHL through, then suture them under tension with the foot at neutral. Evidence is limited, but theoretically this provides better muscle balance." - Drill hole through talar articular cartilage causes arthritis - Excessive tension on transfer causes necrosis - Tendon pullout if fixation inadequate ### Step 10: Equinus Prevention - Talocalcaneal Arthrodesis (Optional) **Most definitive equinus prevention - increasingly popular:** **Technique:** - Debride talar and calcaneal articular cartilage at subtalar joint - Denude to bleeding subchondral bone - Position talus and calcaneus at neutral alignment (hindfoot valgus 5 degrees) - Fix with 1-2 cannulated screws (typically 6.5-7.3mm) from calcaneus into talus - Bone graft from resected navicular/cuboid **Advantages:** - Creates stable, rigid platform - PREVENTS equinus deformity most reliably - Eliminates subtalar motion (already limited in Chopart patients) **Disadvantages:** - Increases surgery time (30-45 minutes) - Nonunion risk 10-15% - Requires protected weight-bearing longer (10-12 weeks) **Exam Key**: "Many surgeons now perform talocalcaneal arthrodesis at the time of Chopart amputation. This creates a stable platform and prevents equinus deformity most reliably. I debride the subtalar joint to bleeding bone, position the hindfoot in 5 degrees valgus and neutral dorsiflexion, and fix with cannulated screws. The nonunion risk is 10-15%, but the equinus prevention is superior." - Malposition (varus or excess valgus) causes abnormal weight-bearing - Nonunion requires revision surgery - Screw penetration into ankle joint ### Step 11: Bone Contouring **Smooth all bone surfaces:** - Use rongeur to smooth talar head and calcaneal cuboid surface - Remove any sharp edges or prominences - Create smooth contour that allows flap to lie flat - If arthrodesis NOT performed: preserve articular cartilage but smooth edges - If arthrodesis performed: ensure adequate bone opposition **Check flap fit:** - Bring plantar flap dorsally - Ensure flap lies flat over bone without tension - No bony prominences palpable through flap **Exam Key**: "I carefully smooth all bone surfaces with a rongeur. Any bony prominence will cause pressure ulceration through the flap. If preserving the joints, I avoid violating subchondral bone. If performing arthrodesis, I ensure adequate bleeding bone surfaces for fusion." - Bony prominences cause pressure ulcers - Excessive bone removal weakens structure - Violation of articular cartilage if preserving joints ### Step 12: Flap Inset and Anchoring **Position plantar flap:** - Release tourniquet and achieve hemostasis (critical - see next step) - Bring plantar flap dorsally over talus and calcaneus - Check for tension - flap MUST lie flat without any pull - If tension present: revise bone further or accept that amputation level too distal **Anchor flap to prevent migration:** - Suture plantar aponeurosis to dorsal periosteum with 2-0 absorbable sutures - Anchor to tendon stumps if available - Multiple interrupted sutures distributing load - Goal: Prevent distal migration of flap, maintain sensate plantar skin over weight-bearing surfaces **Exam Key**: "I anchor the plantar flap to dorsal structures with multiple absorbable sutures. This prevents distal migration over time and ensures the sensate plantar skin remains positioned over the weight-bearing talus and calcaneus. The flap must lie flat without any tension - tension is the number one cause of flap failure." - Tension on flap causes ischemia and necrosis (most common cause of failure) - Inadequate anchoring allows flap to migrate, exposing bone dorsally - Sutures through neurovascular bundles cause injury ### Step 13: Meticulous Hemostasis and Drainage **CRITICAL STEP - hematoma compromises flap perfusion:** **Release tourniquet:** - Deflate tourniquet completely - Allow 10 minutes for normal blood pressure to re-establish - Identify ALL bleeding vessels **Achieve hemostasis:** - Bipolar electrocautery for small vessels - Suture ligate larger vessels (avoid electrocautery near nerves) - Do NOT close until bone-dry hemostasis achieved - Hematoma is a major cause of flap failure **Place drain:** - Deep drain beneath flap - Exit lateral or medial to incision (NOT through flap) - Remove at 24-48 hours **Exam Key**: "I achieve meticulous hemostasis with the tourniquet deflated. Hematoma beneath the flap compromises perfusion and increases infection risk. I use bipolar cautery carefully, avoiding the plantar nerves. I place a deep drain to prevent fluid accumulation, exiting away from the neurovascular bundles." - Hematoma causes flap ischemia and infection - Electrocautery near plantar nerves causes nerve injury - Drain through neurovascular bundle causes injury ### Step 14: Layered Closure **Deep layer:** - Approximate subcutaneous tissue with 3-0 absorbable sutures - Reduce dead space - NO tension on skin edges **Skin closure:** - Interrupted nylon or staples - Approximate plantar flap edge to dorsal skin edge - Ensure good flap contact with underlying bone - Leave 1-2mm gaps between sutures if edema present (can tighten in dressing) **Dressing:** - Non-adherent gauze over incision - Fluffed gauze padding over entire stump - Soft roll and elastic wrap (loose - no circumferential constriction) - Posterior splint from toes to knee **CRITICAL: Splint position:** - Foot at NEUTRAL (90 degrees) - NEVER plantarflexion (encourages equinus) - Knee at 30 degrees flexion (reduces Achilles tension) **Exam Key**: "I close in layers without any tension. The key is that the plantar flap must reach the dorsum easily - if there's tension, the amputation level is wrong. I apply a bulky padded dressing and posterior splint with the foot at NEUTRAL position. Splinting in plantarflexion encourages equinus contracture." - Tension on closure causes dehiscence and flap necrosis - Splint in plantarflexion causes equinus contracture - Tight circumferential dressing causes compartment syndrome ### Complication Rates Summary - **Overall complication rate**: 60-80% (higher than Syme's or BKA) - **Revision to higher level**: 20-40% at 5 years - **Successful prosthetic fitting**: 30-50% - **Patient satisfaction**: Lower than Syme's amputation ### Why Chopart Has Fallen Out of Favor Many surgeons now preferentially perform Syme's amputation or BKA instead of Chopart due to: 1. High equinus deformity rate (30-50%) 2. High wound complication rate (15-25%) 3. Difficulty with prosthetic fitting 4. Frequent revision to higher level (20-40%) 5. Lower patient satisfaction **Chopart still indicated when:** - Patient specifically refuses higher amputation - Religious/cultural requirements for tissue preservation - Surgeon highly experienced with technique and equinus prevention strategies ### Immediate (0-2 weeks): - **Hospital stay**: 3-5 days (longer if diabetic, infection) - **Dressing**: Bulky padded dressing, posterior splint foot at neutral - **Weight-bearing**: NON-weight bearing, strict bedrest day 1 - **Drain**: Remove at 24-48 hours when output less than 30mL per 24hrs - **Analgesia**: PCA or epidural days 1-2, then oral (paracetamol, oxycodone, gabapentin for neuropathic) - **DVT prophylaxis**: Enoxaparin 40mg SC daily (mechanical if high bleeding risk) - **Glycemic control**: Target glucose 6-10 mmol/L in diabetics - **Dressing change**: First change at 48-72 hours, assess flap perfusion ### Early (2-6 weeks): - **Wound care**: Dressing changes every 2-3 days, monitor flap viability - **Splinting**: Posterior splint in neutral, change weekly to assess for equinus - **Weight-bearing**: Non-weight bearing, walker/crutches - **Suture removal**: 3-4 weeks (longer if diabetic, delayed healing) - **Serial casting**: If equinus developing, weekly casts to maintain neutral - **Physiotherapy**: Upper body strengthening, transfer training, contralateral leg strengthening ### Intermediate (6-12 weeks): - **AFO fitting**: Custom AFO to maintain neutral position, usually required long-term - **Weight-bearing progression**: Gradual progressive weight-bearing 6-8 weeks if wound healed - **Bone healing**: If arthrodesis performed, confirm union on X-ray (10-12 weeks) - **Prosthetic consultation**: Evaluate for prosthetic filler or custom prosthesis - **Gait training**: Physical therapy for gait with AFO/prosthesis ### Long-term (3+ months): - **Prosthetic fitting**: Custom shoe filler with carbon fiber plate, or custom prosthesis - **AFO**: 80% require long-term AFO for stability - **Follow-up**: 3-monthly first year, then 6-monthly - **Monitor for**: Equinus development, skin breakdown, ulceration - **Revision rate**: 20-40% require revision to higher level by 5 years ### Red Flags Requiring Urgent Review: - Flap discoloration (dusky, blue, black) - vascular compromise - Wound dehiscence with bone exposure - Fever, systemic signs of infection - Progressive equinus deformity - Pressure ulceration - Uncontrolled pain ## References 1. Pinzur MS, Stuck RM, Sage R, Hunt N, Rabinovich Z. Syme ankle disarticulation in patients with diabetes. J Bone Joint Surg Am. 2003;85(9):1667-1672. doi:10.2106/00004623-200309000-00002 2. Pinzur MS, Smith D, Osterman H. Syme ankle disarticulation in peripheral vascular disease and diabetic foot infection: the one-stage versus two-stage procedure. Foot Ankle Int. 1995;16(3):124-127. doi:10.1177/107110079501600304 3. Bowker JH, San Giovanni TP, Pinzur MS. North American experience with knee disarticulation with use of a posterior myofasciocutaneous flap. J Bone Joint Surg Am. 2000;82(11):1571-1574. 4. Sanders LJ, Dunlap G. Transmetatarsal amputation. A successful approach to limb salvage. J Am Podiatr Med Assoc. 1992;82(3):129-135. doi:10.7547/87507315-82-3-129 5. Dillon MP, Fatone S. Deliberations about the functional benefits and complications of partial foot amputation: do we know the full story? Med Hypotheses. 2013;81(4):754-761. doi:10.1016/j.mehy.2013.07.037 6. Wagner FW Jr. Amputations of the foot and ankle. Current status. Clin Orthop Relat Res. 1977;(122):62-69. 7. Early JS, Hansen ST. Surgical reconstruction of the diabetic foot: a salvage approach for midfoot collapse. Foot Ankle Int. 1996;17(6):325-330. doi:10.1177/107110079601700604 8. Catanzariti AR, Mendicino R, Haverstock B. Ostectomy for diabetic neuroarthropathy involving the midfoot. J Foot Ankle Surg. 2000;39(5):291-300. doi:10.1016/s1067-2516(00)80047-8 9. Harris WR. The classic: Syme's amputation: the technical details essential for success by Austen Harris. Clin Orthop Relat Res. 2012;470(4):947-950. doi:10.1007/s11999-011-2195-6 10. Pinzur MS, Pinto MA, Saltzman M, Batista F, Gottschalk F, Juknelis D. Health-related quality of life in patients with transtibial amputation and reconstruction with bone bridging of the distal tibia and fibula. Foot Ankle Int. 2006;27(11):907-912. doi:10.1177/107110070602701107

Chopart Amputation (Transverse Tarsal Amputation)

Chopart Amputation (Transverse Tarsal Amputation)