Dual incision: Ollier lateral + medial | subtalar + talonavicular + calcaneocuboid fusion | intermediate
- Triple arthrodesis fuses the subtalar (talocalcaneal), talonavicular and calcaneocuboid joints simultaneously, eliminating all hindfoot motion and creating a rigid plantigrade platform. The talonavicular joint is the biomechanical keystone — Astion et al showed any arthrodesis that includes it reduces remaining hindfoot motion to roughly 2 degrees — and it is the joint classically most vulnerable to non-union.
- Indications span the full spectrum of rigid, painful hindfoot deformity: posterior tibial tendon dysfunction Stage III-IV, rigid cavovarus (Charcot-Marie-Tooth disease, residual clubfoot, poliomyelitis), spastic planovalgus (cerebral palsy, stroke) and failed prior hindfoot surgery with arthritis across two or more of the three joints.
- Hindfoot alignment at fusion is the single most important determinant of outcome — fuse the heel in roughly 0-5 degrees of valgus relative to the tibial axis; any varus is unacceptable and drives lateral column overload and accelerated ankle arthritis. Pell, Myerson and Schon showed patient satisfaction was significantly associated with postoperative alignment, not with the presence of ankle arthritis.
- Non-union vulnerability runs talonavicular (highest, smallest contact area relative to the corrective moment), then calcaneocuboid, then subtalar — though per-joint rates vary between series, so quote the principle and modern overall rates in the order of a few percent per joint rather than fixed numbers.
- Stress is transferred to adjacent joints: degenerative change in the ankle and midtarsal joints, pseudarthrosis, talar avascular necrosis and residual deformity are all documented on long-term review (Angus and Cowell, 1986; 80 feet, mean 13 years). Patients must be counselled pre-operatively about this natural history.
When & Why
The indication. Triple arthrodesis is reserved for a rigid, painful hindfoot deformity or hindfoot arthritis that has failed non-operative care (a minimum 3-6 months of orthoses, physiotherapy and analgesia) and cannot be corrected by soft-tissue balancing or an isolated joint fusion. Fusing all three joints sacrifices every remaining degree of hindfoot motion, so it is a salvage operation — the goal is a stable, plantigrade, pain-free foot, not a mobile one. Absolute indications - Rigid, painful planovalgus (flatfoot) not correctable by soft-tissue procedures alone — typically posterior tibial tendon dysfunction Stage III (rigid deformity, not passively correctable) or Stage IV (associated ankle valgus).
- Rigid cavovarus from Charcot-Marie-Tooth disease, residual clubfoot or post-poliomyelitis sequelae, with documented joint degeneration or intractable lateral column pain.
- Spastic hindfoot deformity (cerebral palsy, or acquired spasticity from stroke or traumatic brain injury) causing a fixed, function-limiting valgus or equinovalgus foot.
- Severe symptomatic hindfoot arthritis across two or more of the three hindfoot joints after failure of conservative management. Relative indications - Failed previous hindfoot surgery (an isolated subtalar fusion, or a calcaneal osteotomy with secondary talonavicular arthritis) where further joint-sparing reconstruction is not feasible.
- Severe symptomatic tarsal coalition with secondary arthritic change in the adjacent hindfoot joints.
- Selected, stable neuropathic (Charcot) hindfoot deformity with good bone stock.
- Painful rigid hindfoot in inflammatory arthropathy (rheumatoid arthritis) where all three joints are involved. Contraindications - Flexible, passively correctable deformity amenable to soft-tissue balancing or an isolated joint procedure.
- Active infection within the surgical field.
- Severe peripheral vascular disease inadequate for wound healing (ABPI less than 0.5, or an absent palpable dorsalis pedis/posterior tibial pulse).
- Significant medical comorbidity precluding elective anaesthesia.
- Unrealistic expectations — the patient must accept that heel-to-toe gait and walking on uneven ground are permanently altered. Posterior tibial tendon dysfunction — where triple arthrodesis fits. PTTD is staged I to IV, and the staging dictates the operation. Triple arthrodesis is the primary surgical treatment for Stage III (rigid hindfoot valgus with arthritic change). In Stage IV (Stage III plus ankle valgus tilt) triple arthrodesis alone is insufficient and the ankle must be addressed — deltoid reconstruction or a staged total ankle replacement. It is not indicated in Stage II, where the deformity is still flexible and passively correctable and is managed by soft-tissue reconstruction (medial displacement calcaneal osteotomy, lateral column lengthening and FDL transfer). The full staging table is reproduced in Background & Evidence. Consent. Counsel specifically for: the expected loss of hindfoot motion and a permanently modified gait (difficulty on uneven ground, no running or jumping sports); a small but real non-union risk (highest at the talonavicular joint); progressive adjacent-joint (ankle and midtarsal) arthritis over years from transferred stress; lateral-foot numbness or a painful sural neuroma; lateral wound problems; and the 6-week non-weight-bearing period. Setup. Lateral decubitus position gives equal access to medial and lateral hindfoot without repositioning; a thigh tourniquet (250-300 mmHg after exsanguination) gives a bloodless field. Confirm fluoroscopy (mini or full C-arm) is available before draping — intra-operative AP, lateral and hindfoot alignment views are essential. Spinal or general anaesthesia with a popliteal sciatic block for post-operative analgesia.
The Operation
The goal is to expose all three hindfoot joints through a dual-incision approach, remove every articular surface down to bleeding cancellous bone, correct the deformity to a plantigrade foot with the heel in 0-5 degrees of valgus, and fix each joint rigidly. The exposure — a lateral Ollier incision for the subtalar and calcaneocuboid joints and a separate medial incision for the talonavicular joint — is laid out in full as the first steps below.
Operative sequence
- Lateral decubitus, operative limb uppermost; thigh tourniquet; pad all bony prominences; fluoroscopy positioned.
- Mark both incisions before inflation: the lateral Ollier incision from 1.5 cm below and posterior to the fibular tip to the base of the fourth metatarsal (approximately 8-10 cm oblique), and the medial incision as a 5-6 cm longitudinal line centred dorsomedially over the talonavicular joint (which lies roughly 3-4 cm distal to the medial malleolus tip).
- Sharp full-thickness skin incision to deep fascia with no undermining — the lateral hindfoot skin has a tenuous blood supply and full-thickness flaps are mandatory.
- Identify the sural nerve running within 1 cm of the posteroinferior wound margin, posterior to the peroneal tendons; protect it with a vessel loop for the entire case.
- Incise deep fascia in line with the peroneal tendons and retract the tendons posteriorly with a soft retractor.
- The internervous plane lies between the peroneal tendons (posterior, peroneal artery territory) and extensor digitorum brevis (anterior, anterior tibial artery territory).
- Sharply detach the EDB origin from the anterolateral calcaneus and reflect it distally — this is the key manoeuvre that exposes the sinus tarsi and gives access to both lateral joints through one wound.
- Excise the sinus tarsi fat pad sharply to expose the roof of the tarsal canal and the interosseous ligament (the sinus contains the fat pad, the interosseous talocalcaneal ligament and the cervical ligament).
- Divide the cervical ligament anteriorly and the interosseous ligament posteriorly to open the subtalar joint.
- The posterior facet is now visible — the concave posterior talar surface articulating with the convex posterior calcaneal surface (the posterior facet is the largest of the three subtalar facets and the primary weight-bearing surface). Insert a small laminar spreader to distract and visualise the cartilage.
- Continue the dissection anterolaterally along the calcaneus toward the calcaneocuboid joint — a saddle-shaped joint between the convex anterior calcaneus and concave posterior cuboid.
- Incise the CC joint capsule longitudinally and distract with a laminar spreader; the bifurcate ligament (calcaneocuboid and calcaneonavicular components) lies just medial and may be partially released for exposure.
- Confirm the level with fluoroscopy if uncertain.
- Longitudinal 5-6 cm incision over the dorsomedial talonavicular joint; blunt dissection through subcutaneous fat to protect the dorsal cutaneous branches of the superficial peroneal nerve that fan across the dorsum.
- Identify and retract the dorsalis pedis artery (with its deep peroneal nerve) dorsally — it crosses the TN joint on its dorsomedial aspect; confirm flow by palpation or Doppler.
- Open the tibialis posterior tendon sheath and retract the tendon plantarward to improve inferior access; incise the TN capsule dorsomedially and insert a laminar spreader.
- The joint is the convex talar head articulating with the concave navicular — the medial column of the acetabulum pedis. Do not begin cartilage removal until both the dorsal and plantar aspects are visible; the plantar-medial subchondral bone is the key surface for graft contact.
- This step determines fusion success. Use sharp osteotomes and curettes to remove all articular cartilage down to bleeding cancellous bone at the subtalar, talonavicular and calcaneocuboid joints.
- Critically, also remove the calcified cartilage layer and the first 1-2 mm of subchondral plate to expose cancellous bone — leaving the calcified zone is the commonest technical error causing non-union.
- Perforate the subchondral bone with a 2 mm drill (multiple holes at each joint) to stimulate vascular ingrowth — especially important at the talonavicular joint given its small contact area.
- Irrigate to remove cartilage debris.
- Planovalgus (flatfoot): correct subtalar valgus to 0-5 degrees; plantarflex and adduct the TN joint to reduce the abducted forefoot; check for residual forefoot supination (a plantarflexed first ray may need a concurrent first metatarsal plantarflexion osteotomy). If the calcaneus will not reduce to neutral through joint resection alone, add a medial-displacement or lateral-column calcaneal osteotomy.
- Cavovarus (CMT/clubfoot): the heel is in varus and must be swung to 0-5 degrees valgus — the subtalar resection is a wedge with its base medial, apex lateral. Reduce the plantarflexed, adducted navicular to neutral; residual forefoot cavus may need a dorsal closing-wedge first metatarsal osteotomy.
- Target alignment: heel 0-5 degrees valgus (never varus); forefoot plantigrade (first and fifth metatarsal heads equidistant from the ground); tibiotalar congruence maintained.
- Hold the correction manually or with bone-holding clamps and insert provisional K-wires across each joint.
- Obtain fluoroscopy — AP, lateral and a Saltzman hindfoot alignment view — and assess heel position with simulated weight-bearing.
- Do not place definitive screws until alignment is confirmed on fluoroscopy.
- Subtalar joint: two large partially-threaded cannulated screws (6.5 mm or 7.0 mm), inserted from the posterior calcaneal tuberosity across the posterior facet into the talar body (a second parallel or slightly divergent screw adds rotational control).
- Talonavicular joint: one large partially-threaded cannulated screw (6.5 mm) from the navicular tuberosity into the talar head, plus an optional 3.5 mm anti-rotation screw or staple — this joint has the highest non-union rate, so secure fixation is paramount.
- Calcaneocuboid joint: one partially-threaded screw (4.5 mm or 6.5 mm) from the calcaneus into the cuboid, or a compression staple/small plate if bone stock is poor.
- Confirm final implant position, joint compression and alignment on fluoroscopy.
- Indicated for significant bone deficit after deformity correction, poor bone stock (rheumatoid, avascular necrosis) or revision.
- Autograft from the iliac crest (gold standard for volume) or a distal tibial window (less donor morbidity); combine with local bone saved from joint preparation. Morselised cancellous allograft, demineralised bone matrix or synthetic calcium phosphate are acceptable supplements for smaller defects.
- Lateral wound: reattach the EDB origin to periosteum where possible; close capsule and periosteum with 0 or 2-0 absorbable sutures; close deep fascia over the peroneal tendons; subcutaneous 2-0 absorbable and 3-0 monofilament skin or staples; drain only if haemostasis is inadequate.
- Medial wound: close the TN capsule and re-approximate the tibialis posterior sheath; subcutaneous and skin as lateral.
- Deflate the tourniquet and check perfusion. Apply a well-padded plaster back-slab or boot with the ankle neutral and the heel protected.
Runs posterior to the peroneal tendons along the lateral border of the foot, typically within 1 cm of the calcaneocuboid joint line. It is vulnerable during the lateral (Ollier) approach. Identify it early, retract it posteriorly with a vessel loop, and avoid traction or over-coagulation. Injury causes permanent lateral-foot numbness and may form a painful neuroma.
Crosses the talonavicular joint on its dorsomedial aspect with the deep peroneal nerve, and is at risk during the medial exposure and TN screw placement. Identify it before deepening the medial dissection, retract it with a loop, and confirm pulsatile flow before closure. Injury compromises dorsal foot perfusion and wound healing.
The intermediate dorsal cutaneous branch of the superficial peroneal nerve fans across the dorsum and passes close to the medial incision margin. Use a sharp skin incision only and blunt dissection through the subcutaneous fat, with cautious retraction. Injury causes dorsal dysaesthesia and a painful scar.
The single most consequential intra-operative decision is hindfoot alignment. Fuse the heel in roughly 0-5 degrees of valgus relative to the tibial axis — any degree of varus is unacceptable and causes lateral-column overload, fifth-metatarsal stress fractures and accelerated ankle arthritis. Confirm with fluoroscopy (AP, lateral and a Saltzman hindfoot alignment view) and a manual simulated weight-bearing assessment BEFORE placing definitive screws. If correction cannot be achieved through joint resection alone, add a calcaneal osteotomy; do not accept varus to avoid a reoperation.
The TN joint has the smallest bony contact area relative to the corrective moment demanded of it and is classically the most vulnerable to non-union. Remove cartilage down to bleeding cancellous bone including the calcified layer, perforate the subchondral plate with a 2 mm drill at multiple points, and ensure the plantar-medial aspect is fully prepared — it is the most commonly incompletely prepared surface. Astion et al showed any arthrodesis including the TN joint reduces remaining hindfoot motion to roughly 2 degrees, so its alignment and fixation carry the whole construct.
In planovalgus deformity the navicular is abducted and the talonavicular joint cannot be adequately prepared or fixed through the lateral (Ollier) approach alone. A separate medial incision gives direct dorsal and plantar access to the TN joint. Examiners specifically probe whether you know the lateral approach is insufficient for TN work in an abducted flatfoot.
Lateral wound dehiscence is the leading cause of deep infection and salvage failure because the Ollier incision overlies subcutaneous bone with minimal soft-tissue padding and a tenuous blood supply (peroneal artery perforators). Maintain full-thickness flaps with no subcutaneous undermining, minimise soft-tissue stripping, and insist on smoking cessation before elective surgery.
Aftercare & Complications
Rehabilitation | Phase | Timing | Weight-bearing | Milestones | |-------|--------|----------------|------------| | Immobilisation | 0-6 weeks | Non-weight-bearing in a below-knee cast or boot | Wound check at 2 weeks; sutures out at 12-14 days; elevate for the first 48-72 hours | | Transition | 6-12 weeks | Partial then full weight-bearing in a boot from 6 weeks | Serial radiographs at 6, 10 and 14 weeks; CT if TN union is equivocal | | Recovery | 3-12 months | Footwear by 10-12 weeks | Community walking restored over 3-6 months; AOFAS score plateaus at 12-18 months | Most patients walk independently in standard footwear by 4-6 months and return to strenuous activity (hiking, manual labour) by 6-9 months. A rocker-bottom sole or cushioned insole reduces residual ankle stress. Running, jumping and pivoting sports are restricted permanently; walking on severely uneven ground remains difficult and must be forewarned. Surveillance standing ankle radiographs are taken annually or biennially from about 5 years to watch for progressive ankle arthritis. Complications
- Recognition
- Persistent TN pain beyond 4 months; no progressive bridging trabeculae on serial films; screw loosening or breakage; CT confirms absent bridging bone
- Prevention
- Meticulous cartilage removal including the calcified zone; subchondral drill perforations; rigid fixation; smoking cessation; optimise diabetes and nutrition; bone graft for high-risk patients
- Management
- Asymptomatic: observe. Symptomatic: revision fusion with hardware removal, re-preparation to bleeding bone, iliac-crest autograft and rigid fixation — counsel that revision non-union rates exceed primary
- Recognition
- Heel not at 0-5 degrees valgus on standing inspection or the Saltzman view; lateral foot and fifth-metatarsal pain; lateral ankle joint-space narrowing
- Prevention
- Intra-operative fluoroscopy (AP, lateral, Saltzman) before definitive screws; never accept varus — revise before closing
- Management
- Before solid fusion (within 3 months): return to theatre, correct and re-fix. Established malunion: a calcaneal (Dwyer) lateral closing-wedge osteotomy; address ankle arthritis if present
- Recognition
- Dusky wound edges or failure of primary healing at days 5-10; serous or purulent discharge; risks: smoking, diabetes, PVD, excess skin tension
- Prevention
- Full-thickness flaps with no undermining; minimal soft-tissue stripping; vascular assessment; mandatory smoking cessation 4 or more weeks pre-op
- Management
- Superficial without exposed implant: local care and negative-pressure dressing awaiting granulation. Deep or exposed hardware: urgent debridement, tissue culture and targeted antibiotics; plastic-surgery reconstruction for refractory wounds
- Recognition
- Gradual ankle pain years after fusion; standing films show joint-space narrowing and osteophytes; reduced walking distance (Bednarz et al found ankle arthrosis in 38% and some talar tilt in 73% of feet with mortise views)
- Prevention
- Fuse in 0-5 degrees valgus; preserve residual ankle motion; body-weight optimisation; moderate-impact activity
- Management
- Supportive footwear with a rocker-bottom sole and NSAIDs; total ankle replacement for salvage; ankle fusion as a last resort
- Recognition
- Lateral-foot or heel numbness; positive Tinel posterior to the incision; possible painful neuroma at 3-6 months
- Prevention
- Identify the sural nerve posterior to the peroneal tendons early; protect with a vessel loop; avoid traction or over-coagulation
- Management
- Neuropraxia: observe (most recover by 3-6 months). Persistent neuroma: desensitisation and gabapentin; surgical excision with burial in a muscle belly
- Recognition
- Progressive mid-foot pain; naviculocuneiform or TMT tenderness; dorsal spurring and joint-space narrowing on weight-bearing films, typically 5-15 years post-fusion
- Prevention
- Avoid over-resection of midtarsal joints; correct alignment to reduce stress concentration
- Management
- Rigid insole or rocker sole and activity modification; extend the fusion to the involved midfoot joints (naviculocuneiform, first TMT) if refractory
Managing established TN non-union. Confirm with CT — plain radiographs can mislead, with apparent bridging callus that is not true osseous union. Before any revision, optimise the reversible risk factors (glycaemic control, smoking cessation, nutrition — albumin and vitamin D). Revision requires complete take-down of the previous fixation, thorough re-preparation to fresh bleeding bone, supplemental iliac-crest autograft and rigid fixation, followed by 12-16 weeks of protected weight-bearing. Managing varus malposition. Even 5 degrees of varus markedly increases lateral forefoot pressure and accelerates ankle arthritis. If recognised intra-operatively, revise the bone resection and re-check alignment before closure; if recognised within 3 months before solid fusion, return to theatre to correct and re-fix; if it is an established malunion with solid fusion, a calcaneal (Dwyer) lateral closing-wedge osteotomy shifts the heel into valgus, with adjunct tibiotalar reconstruction if ankle arthritis is established.
Viva & Exam Focus
STCSTC — the three joints in order
FAVEFAVE — prevent malposition
Clinical Decision Scenarios
Practise clinical reasoning and management decisions out loud
“A 58-year-old woman has a 10-year history of progressive left foot deformity and pain — a rigid flatfoot with heel valgus, an abducted forefoot and uncovering of the talar head. Custom orthotics and physiotherapy for 18 months have failed. Radiographs show arthritic change across the subtalar and talonavicular joints. She is otherwise fit. What is your assessment and surgical plan?”
“A 35-year-old man with Charcot-Marie-Tooth disease has bilateral cavovarus feet, progressive lateral ankle instability, callosity under the fifth metatarsal heads and lateral foot pain. The left foot has rigid hindfoot varus, peroneal weakness and claw toes, and bracing has failed. What surgical options exist and how would you approach triple arthrodesis here?”
“Walk me through the operative steps of triple arthrodesis. What is your fixation strategy for each joint and how do you confirm alignment intra-operatively?”
Indications
- PTTD Stage III (rigid, non-correctable planovalgus with subtalar/TN arthritis) — Stage II is flexible and needs soft-tissue reconstruction, not triple arthrodesis
- Rigid cavovarus (CMT, residual clubfoot, poliomyelitis) — only when the Coleman block does NOT correct the heel
- Spastic hindfoot (cerebral palsy, stroke) with function-limiting rigid valgus or equinovalgus
- Failed prior hindfoot surgery with arthritis across two or more hindfoot joints
- Painful rigid hindfoot in inflammatory arthropathy (RA) involving all three joints
Anatomy & approaches
- Subtalar: three facets (posterior largest); tarsal sinus entry; two large cannulated screws, posterior calcaneus to talar body
- Talonavicular: convex talar head into concave navicular; biomechanical keystone; classically most vulnerable to non-union; medial incision in flatfoot
- Calcaneocuboid: lateral-column anchor; saddle joint, small contact area; one screw or staple
- Lateral (Ollier): fibular tip to fourth MT base, between peroneal tendons and EDB; protect the sural nerve 1 cm posterior
- Medial: dorsomedial over the TN joint; protect the dorsalis pedis artery dorsally; retract tibialis posterior plantarward
Operative steps
- Lateral decubitus, thigh tourniquet; mark both incisions before inflation; fluoroscopy ready
- Lateral Ollier incision: full-thickness flaps, no undermining; identify and protect the sural nerve first
- Detach EDB from the calcaneus and reflect distally — the key step exposing the sinus tarsi and both lateral joints
- Excise the sinus tarsi fat pad; divide the interosseous talocalcaneal ligament to open the posterior facet
- Medial incision: blunt subcutaneous dissection (protect SPN branches); protect dorsalis pedis; retract tibialis posterior plantarward
- Meticulous cartilage removal at all three joints — include the calcified layer and add subchondral drill perforations, especially at TN
- Provisional K-wires, then fluoroscopy (AP, lateral, Saltzman) BEFORE definitive screws; target 0-5 degrees heel valgus
- Fixation: two 6.5 mm screws subtalar; one 6.5 mm (plus optional anti-rotation) TN; one 4.5-6.5 mm or staple CC
Five danger zones
- Sural nerve: 1 cm posterior to the lateral incision — protect early; injury causes a lateral-foot neuroma
- Dorsalis pedis artery: dorsal aspect of the TN joint — identify before cartilage removal
- Dorsal cutaneous branches (SPN): at risk in the medial approach — blunt subcutaneous dissection only
- Lateral wound necrosis: full-thickness flaps, no undermining; mandatory pre-op smoking cessation
- Varus malposition: the most consequential error — never accept varus; 0-5 degrees valgus is mandatory
Technique pearls
- FAVE mnemonic: Fluoroscopy before fixation, Align 0-5 degrees valgus, Verify forefoot plantigrade, Examine ankle congruence
- Dual incision preferred for flatfoot — lateral TN access is inadequate when the navicular is abducted
- The TN joint is the keystone — its fusion abolishes hindfoot motion (Astion); prioritise its preparation and fixation
- Subchondral drill perforations at every joint (especially TN) stimulate vascular ingrowth and reduce non-union
- Coleman block test for cavovarus — a correctable heel means a first metatarsal osteotomy may avoid fusion
Complications & post-op
- TN non-union: prevent with meticulous prep, drill perforations and rigid fixation; diagnose with CT; revise with autograft
- Varus malposition (5-10%): intra-op fluoroscopy before screws; early revision; calcaneal osteotomy for established malunion
- Lateral wound dehiscence (5-15%): full-thickness flaps, no smoking, vascular assessment; NPWT for superficial, debridement for deep
- Progressive ankle arthritis (Bednarz: 38% arthrosis on mortise views): counsel pre-op; rocker sole; TAA for salvage
- Post-op: non-weight-bearing 6 weeks; partial weight-bearing in a boot at 6 weeks; radiographs at 6/10/14 weeks; footwear at 10-12 weeks
High-yield exam concepts
- Stage III vs II: II is flexible and needs soft-tissue reconstruction; III is rigid and arthritic and needs triple arthrodesis — the classic viva trigger
- Angus and Cowell (1986): 80 feet, mean 13 years; subjectively pleased but high ankle/midfoot degeneration, pseudarthrosis and talar AVN; rigid equinovarus worst
- Pell, Myerson and Schon (2000): 132 feet; satisfaction 8.3/10 and 91% would repeat; tied to alignment, not ankle arthritis
- Astion (1997): any arthrodesis including the TN joint leaves roughly 2 degrees of hindfoot motion — the keystone rationale
- Heel alignment non-negotiable: 0-5 degrees valgus; any varus is a technical failure
Background & Evidence
Epidemiology. Triple arthrodesis is performed across a wide age range for end-stage rigid hindfoot deformity. The commonest adult indication in most series is posterior tibial tendon dysfunction reaching Stage III-IV; neurological deformity (Charcot-Marie-Tooth disease is the prototype hereditary motor-sensory neuropathy driving cavovarus) and spastic conditions (cerebral palsy) predominate in younger patients. Pathoanatomy. The three joints form a functional complex. The subtalar joint has three facets (posterior, middle and anterior) with its axis oblique in all three planes (roughly 42 degrees from horizontal and 16 degrees from sagittal), giving combined inversion-eversion of about 30-40 degrees. The talonavicular joint is the convex talar head into the concave navicular, forming the medial column of the acetabulum pedis with the spring (calcaneonavicular) ligament; the navicular covers only part of the talar head, giving a small contact area relative to the corrective moment — the usual explanation for its non-union vulnerability. The calcaneocuboid joint is a saddle joint that anchors the lateral column; fusing it locks lateral-column length and prevents further forefoot abduction. Astion's cadaveric model established that including the talonavicular joint in any arthrodesis collapses remaining hindfoot motion to roughly 2 degrees, making it the biomechanical keystone.
- Findings
- Tenosynovitis, tendon intact, flexible foot
- Management
- Conservative; tendon debridement if refractory
- Findings
- Attenuated or ruptured tendon; deformity flexible and passively correctable
- Management
- Medial displacement calcaneal osteotomy, lateral column lengthening and FDL transfer — triple arthrodesis NOT indicated
- Findings
- Rigid hindfoot valgus with arthritic change
- Management
- Triple arthrodesis — the primary surgical treatment
- Findings
- Stage III plus ankle (tibiotalar) valgus tilt
- Management
- Triple arthrodesis alone is insufficient — add deltoid reconstruction or a staged total ankle replacement
Key evidence. Angus and Cowell (1986; 80 feet, mean 13-year follow-up) found most patients subjectively pleased but a high incidence of ankle and midfoot degeneration, pseudarthrosis, talar avascular necrosis and residual deformity, with rigid equinovarus producing the worst results — establishing the need for honest long-term counselling. Pell, Myerson and Schon (2000; 111 patients, 132 feet, mean 5.7 years) used rigid fixation with joint-surface realignment and no wedge resection, achieving satisfaction of 8.3 out of 10 with 91% willing to repeat the procedure; satisfaction was significantly associated with postoperative alignment (p = 0.001) but not with ankle arthritis, with only three non-unions in the series. Astion et al (1997) provided the biomechanical keystone rationale. Bednarz et al (1999; 63 feet) confirmed large functional gains (AOFAS 28 to 81) but documented ankle arthrosis in 38% and some talar tilt in 73% of feet with mortise views, with two varus and two valgus malunions and two non-unions. Wetmore and Drennan (1989; CMT, mean 21-year follow-up) showed that in progressive neuropathy nearly half of feet were rated poor at long-term review with recurrent cavovarus, supporting triple arthrodesis as salvage only in severe rigid CMT deformity.
References
Triple arthrodesis. A critical long-term review.
- Retrospective review of 80 feet followed for a mean of 13 years
- Most patients were subjectively pleased, but objective results were less favourable
- High incidence of degenerative change in the ankle and midfoot, plus pseudarthrosis, talar avascular necrosis and residual deformity
- Pre-operative rigid equinovarus deformity produced the majority of poor results
Clinical outcome after primary triple arthrodesis.
- 111 patients (132 feet), mean follow-up 5.7 years; rigid screw fixation with joint-surface realignment and no wedge resection
- Mean satisfaction 8.3 out of 10; 91% would undergo the procedure again
- Patient satisfaction was significantly associated with postoperative alignment (p = 0.001) but NOT with the presence of ankle arthritis
- Only three non-unions in the entire series; postoperative ankle arthritis was significantly more severe than pre-operatively
Motion of the hindfoot after simulated arthrodesis.
- Cadaveric model measuring residual motion after simulated single and combined hindfoot arthrodeses
- Any arthrodesis that included the talonavicular joint reduced motion of the remaining joints to roughly 2 degrees
- Isolated calcaneocuboid fusion had little effect on subtalar motion; isolated subtalar fusion preserved appreciable transverse tarsal motion
- The talonavicular joint had the greatest range of motion and is the key joint of the triple complex
Triple arthrodesis in adults using rigid internal fixation: an assessment of outcome.
- 63 feet in 57 adults, mean follow-up 30 months, treated for hindfoot deformity with secondary arthrosis
- Mean AOFAS ankle-hindfoot score improved from 28 to 81 points (p less than 0.0001); 97% would have the surgery again
- Complications included two varus and two valgus malunions and two non-unions; iliac crest graft used in 89% and heel-cord lengthening in 84%
- Of feet with mortise views, 38% showed ankle arthrosis and 73% some degree of talar tilt postoperatively
Long-term results of triple arthrodesis in Charcot-Marie-Tooth disease.
- 16 patients (30 feet) with CMT, mean age 15 years at surgery, mean follow-up 21 years
- 47% of feet rated poor and a further 30% only fair at long-term review
- Progressive muscle imbalance produced recurrent cavovarus deformity in 7 feet that initially had satisfactory alignment
- Degenerative ankle and midfoot change was seen radiographically in 23 of 30 feet
Isolated subtalar arthrodesis.
- 48 isolated subtalar fusions reviewed for outcome
- 93% satisfied; mean AOFAS ankle-hindfoot score 89
- Union achieved in all cases
The hindfoot alignment view.
- Original description of the hindfoot alignment (Saltzman) view
- Reliable coronal assessment of heel position (interobserver r = 0.97)
- Used before and after hindfoot fusion to quantify alignment
Triple arthrodesis in older adults. Results after long-term follow-up.
- 17 patients (18 feet), mean age 66, mean 42-month follow-up
- Three non-unions (one talonavicular, two calcaneocuboid)
- Progressive ankle and midfoot degeneration documented
- Premature weight-bearing and comorbidity identified as risks
Late complications of fractures of the calcaneus.
- Characterised post-traumatic subtalar and peritalar arthritis after displaced calcaneal fractures
- Established triple arthrodesis as salvage for post-traumatic hindfoot arthritis
- Relevant to understanding indications in post-traumatic deformity
Foot-pressure measurement after triple arthrodesis in adolescents with and without a unilateral spastic condition.
- Pedobarographic analysis after triple arthrodesis in adolescents, including spastic flatfoot
- Demonstrated restoration of a plantigrade pressure distribution following adequate hindfoot correction