Tarsal Navicular Fracture ORIF

Surgical Indications

Absolute Indications

• Displaced intra-articular body fracture with articular step-off greater than 2 mm on the talonavicular or naviculocuneiform surface
• Open navicular fracture — urgent debridement and skeletal stabilisation
• Fracture-dislocation of the midfoot (Chopart involvement) with navicular displacement
• Displaced complete stress fracture (Saxena Type III) through the plantar cortex, or any complete stress fracture that has failed a trial of strict non-weight-bearing
• Large displaced tuberosity avulsion (greater than 5 mm) with posterior tibial tendon dysfunction, or symptomatic nonunion

Relative Indications

• Sangeorzan Type II body fracture with lesser but functionally significant displacement in a high-demand patient
• Comminuted Type III fracture where primary stable fixation is preferred over prolonged casting
• Athlete with a complete (Saxena III) stress fracture requesting the earliest reliable return to sport, after counselling on operative versus non-operative trade-offs
• Symptomatic painful accessory navicular (Type II) refractory to non-operative care, with or without avulsion of the accessory fragment

Contraindications

Absolute:

• Medically unfit for anaesthesia
• Active deep infection at the surgical site (other than an open fracture requiring debridement)
• A non-displaced stress or body fracture that will predictably unite with strict non-weight-bearing — surgery adds risk without benefit

Relative:

• Peripheral vascular disease or diabetes with neuropathy — elevated wound and nonunion risk; optimise and counsel
• Severe comminution where fixation is non-viable — consider external fixation or primary arthrodesis of the involved column
• Tobacco use — elevated nonunion risk; advise cessation before elective fixation

Classification

Sangeorzan Classification — Body Fractures

The operative planning framework for displaced intra-articular navicular body fractures.

Saxena Classification — Stress Fractures

Stratifies navicular stress fractures by completeness and guides operative decision-making.

Evidence for Non-Operative Treatment

Non-displaced body fractures

• Undisplaced or minimally displaced navicular body fractures unite reliably in a non-weight-bearing cast or boot for 6 weeks, followed by a graduated return to weight-bearing.
• Serial radiographs monitor for secondary displacement and arch collapse, which mandate conversion to ORIF.

Partial stress fractures (Saxena I and II)

• Strict non-weight-bearing in a cast or boot for 6 weeks is the foundation. Plain radiographs are frequently normal, so CT or MRI is used to confirm healing.
• Return to sport is graduated and typically takes 4 to 6 months; premature return risks propagation to a complete fracture.

Tuberosity avulsion

• Minimally displaced avulsions are managed symptomatically in a boot or cast for 4 to 6 weeks with the foot plantigrade.

Position and Articulations

The tarsal navicular is a crescent-shaped bone on the medial side of the midfoot, interposed between the talar head proximally and the three cuneiforms distally.

• Proximally — the concave proximal face articulates with the rounded talar head, forming the ball-and-socket talonavicular joint. This joint, combined with the calcaneocuboid joint, constitutes the transverse tarsal (Chopart) joint.
• Distally — the convex distal face articulates with the medial, intermediate and lateral cuneiforms at the three naviculocuneiform joints.
• Laterally — it may articulate with the cuboid at the lateral extremity.
• Medially/Plantarly — the prominent navicular tuberosity projects inferiorly and medially and receives the principal insertion of the posterior tibial tendon.

The Keystone Concept

The navicular is the keystone of both the medial longitudinal arch and the transverse arch. It sits at the apex of the medial column, transferring load from the hindfoot to the forefoot. Disruption of its position shortens the medial column and lowers the arch — the anatomical basis for post-traumatic flatfoot after malreduced navicular fractures.

Blood Supply — The Watershed Zone

The vascular anatomy explains why navicular fractures, and especially central stress fractures, are prone to delayed union, nonunion and avascular necrosis.

• Dorsal supply — branches of the dorsalis pedis artery (the medial tarsal and arcuate branches) enter the dorsal surface.
• Medial supply — branches of the posterior tibial artery, via medial plantar branches, enter at the tuberosity.
• Central zone — these dorsal/lateral and medial vascular inputs converge toward the centre but leave the central third relatively avascular, a watershed zone.

This central avascular territory is where the repetitive compressive load of gait concentrates in athletes, which is why navicular stress fractures characteristically originate in the central third and propagate toward the plantar cortex. It is also why displaced fractures through the centre and central stress fractures heal reluctantly — an anatomic reduction that protects soft-tissue attachments and a prolonged period of non-weight-bearing are mandatory.

Tendon and Ligament Attachments

Dorsal Neurovascular Anatomy — The Operative Hazards

This is the single most examined anatomy for a navicular ORIF.

Dorsalis pedis artery and deep peroneal nerve

• Run together on the dorsum of the foot between the extensor hallucis longus (EHL) and extensor digitorum longus (EDL) tendons.
• They cross the proximal navicular and the talonavicular joint, lying lateral to the EHL tendon, and the artery continues as the first dorsal metatarsal / deep plantar branch into the first webspace.
• Clinical implication: a dorsomedial approach kept between the tibialis anterior and EHL stays medial to this bundle. Lateral retraction of the EHL protects it; straying lateral to EHL endangers the artery.

Superficial peroneal nerve

• Divides into the medial dorsal cutaneous and intermediate dorsal cutaneous branches, which run subcutaneously across the dorsum.
• The medial dorsal cutaneous nerve crosses the navicular region just beneath the skin and is the structure most at risk from a dorsal incision. A transected branch forms a painful neuroma.

Posterior tibial artery and tibial nerve

• Pass posterior to the medial malleolus, behind the tibialis posterior and FDL tendons, and give off the medial plantar branches that supply the tuberosity.
• Relevant to a medial approach but not directly endangered by the standard dorsomedial incision.

Surface Landmarks

• Navicular tuberosity — palpable on the medial border of the foot, about 2 to 3 cm distal and plantar to the medial malleolus, at the insertion of tibialis posterior.
• N spot — the dorsal central prominence of the navicular, the point of maximal tenderness in a stress fracture. Palpate with the foot plantigrade.
• Talonavicular joint — just proximal to the navicular, palpable dorsomedially with passive circumduction of the foot.
• Tibialis anterior tendon — the obvious subcutaneous tendon crossing the medial dorsum to the medial cuneiform; the safe medial border of the dorsomedial incision.

Positioning and Preparation

Patient position: Supine on a radiolucent table with a small ipsilateral bump under the hip to control external rotation and bring the dorsum of the foot uppermost. The foot itself rests on a folded sheet or radiolucent support.

Anaesthesia: General or regional (popliteal/adductor canal block) anaesthesia with an ankle or thigh tourniquet. A thigh tourniquet at 250 to 300 mmHg provides a bloodless field for the dorsal exposure.

Pre-operative checks: Examine and document the dorsalis pedis and posterior tibial pulses and the cutaneous sensation on the dorsum and plantar surfaces (baseline for the medial dorsal cutaneous and plantar nerves). Confirm reduction targets on intra-operative fluoroscopy (AP, oblique and lateral) before draping.

Consent: Counsel specifically on wound complications (dorsal thin skin), hardware prominence requiring later removal, nonunion of a central/stress fracture, post-traumatic arthritis of the TN or NC joint possibly requiring later arthrodesis, and the prolonged 6-week non-weight-bearing period.

Dorsomedial Approach — Step by Step

Step 1: Incision

Mark a dorsomedial longitudinal incision centred over the navicular, running from just proximal to the talonavicular joint to the naviculocuneiform joint. Place it in the interval between the tibialis anterior tendon (medial) and the extensor hallucis longus tendon (lateral), or just dorsal to the tibialis anterior. The skin here is thin; make the incision sharply down to but not through the superficial nerves.

Step 2: Superficial Dissection and Nerve Protection

Raise full-thickness flaps at the deep subcutaneous level, identifying the medial dorsal cutaneous nerve branches and protecting them with vessel loops. Incise the extensor retinaculum and dorsal capsule in line with the skin incision, staying medial to the EHL tendon. Gently retract the EHL laterally, carrying the dorsalis pedis artery and deep peroneal nerve with it.

Step 3: Exposure and Fracture Assessment

Open the dorsal capsule to expose the navicular body and the proximal articular surfaces of the talonavicular and naviculocuneiform joints. Irrigate to clear haematoma and inspect the fracture pattern. Assess comminution, the size and vascularity of the fragments, and the integrity of both articular surfaces. Provisionally reduce the fragments and judge the extent of any bone defect that will need grafting.

Step 4: Reduction

Reduce the articular fragments directly. For a large dorsal fragment (Sangeorzan I), reduce it anatomically onto the plantar piece. For a dorsomedial shear (Sangeorzan II), restore the joint surface and correct forefoot adduction by lengthening the medial column. For comminuted patterns (Sangeorzan III), reconstruct the joint surface fragment by fragment, accepting that the construct will need buttress support. Hold the reduction with fine K-wires before definitive fixation.

Step 5: Fixation

Place definitive fixation perpendicular to the fracture line so that it acts in compression.

• Large fragments — one or two 3.5 mm cortical lag screws (or 2.7 mm for smaller fragments), with the glide hole in the near fragment and a thread hole in the far fragment. Countersink the screw head in the thin dorsal cortex to avoid hardware prominence.
• Comminuted patterns — a lag screw alone will shorten the column. Add a mini-fragment (2.0 to 2.7 mm) neutralisation or bridge plate along the dorsal or dorsomedial navicular; in highly comminuted injuries a plate may temporarily span the talonavicular or naviculocuneiform joint to maintain length, with planned removal once healed.
• Tuberosity avulsion — a small lag screw or tension band capturing the posterior tibial tendon insertion; repair the tendon to bone if the fragment is small.
• Stress fracture (Saxena III) — percutaneous or mini-open placement of one or two compression screws across the central fracture line perpendicular to it, without stripping the dorsal supply.

Step 6: Bone Grafting

For cavitary or comminuted defects in the central body (common in Sangeorzan III), back-fill with autogenous cancellous bone graft from the medial calcaneus or distal tibia, or allograft, to support the reduced articular surface and encourage union in the avascular centre.

Step 7: Closure and Immobilisation

Release the tourniquet, achieve haemostasis, and close the capsule, extensor retinaculum and skin in layers over the protected nerves. Apply a well-padded posterior splint holding the foot plantigrade. Confirm final reduction and hardware position on AP, oblique and lateral fluoroscopy and save the images.

Fixation Summary

Post-operative Protocol

Immobilisation and Weight-bearing

• 0 to 2 weeks — posterior splint, strictly non-weight-bearing, elevation, wound check at 10 to 14 days for suture removal or review.
• 2 to 6 weeks — transition to a non-removable cast or controlled-ankle-motion boot, strictly non-weight-bearing. The central avascular zone must be protected through this period.
• 6 to 10 weeks — graduated weight-bearing in the boot as radiographs/CT show progressing union; commence gentle active foot and ankle range of motion out of the boot.
• 10 to 12 weeks and beyond — wean the boot, progress to normal weight-bearing footwear, begin proprioceptive and strengthening rehabilitation.

Imaging Surveillance

• Radiographs (AP, oblique, lateral, weight-bearing when able) at 2, 6 and 10 to 12 weeks.
• For stress fractures and comminuted body fractures, a CT at 8 to 12 weeks confirms bridging before unrestricted loading — plain films underestimate healing.

Return to Function

• Desk work — 1 to 2 weeks.
• Weight-bearing work — 10 to 12 weeks.
• Driving — once full, pain-free weight-bearing and adequate control (typically 8 to 10 weeks for the right foot).
• Running sports — 4 to 6 months, after CT-confirmed union and a completed rehabilitation programme.

Special Case: Navicular Stress Fracture in the Athlete

Recognition

• Insidious dorsal midfoot pain in a runner or jumping athlete, worsening with activity and easing with rest — the classical presentation.
• Focal tenderness over the N spot (dorsal central navicular).
• Plain radiographs are frequently normal — request CT to show a fracture line or MRI for stress response.

Management Decision

• Partial fractures (Saxena I and II) — strict non-weight-bearing in a cast or boot for 6 weeks, then graduated loading. Return to sport typically 4 to 6 months.
• Complete fractures (Saxena III) — surgical fixation (percutaneous or mini-open compression screws) is favoured to reduce time to union and the nonunion rate, particularly in athletes. Displaced complete fractures are treated with open reduction and internal fixation.
• Address predisposing factors — training load, footwear, biomechanics, relative energy deficiency, and vitamin D/calcium status — before return, or recurrence is likely.

Return-to-Sport Principles

• Symptoms and signs resolved, not merely imaging healed.
• CT evidence of bridging.
• Graduated loading (walk-jog-run-sprint-plyometrics) over 6 to 8 weeks after clearance to load.

Special Case: Tuberosity Avulsion vs Accessory Navicular

Distinguishing the Two

• Acute avulsion — sharp, unilateral fragment at the tibialis posterior insertion, acute focal tenderness after an eversion injury, often with tibialis posterior dysfunction.
• Accessory navicular (os tibiale externum) — bilateral in most, smooth corticated margins, rounded, at the tendon insertion; may become symptomatic chronically. Image the contralateral foot.

Management

• Minimally displaced avulsion (less than 5 mm) — boot or cast for 4 to 6 weeks; most unite or become asymptomatic.
• Displaced avulsion (greater than 5 mm) or symptomatic nonunion — ORIF with a lag screw or tension band and repair of the tibialis posterior insertion.
• Painful accessory navicular refractory to non-operative care — excision of the accessory fragment with advancement of the tibialis posterior tendon (Kidner procedure).

Special Case: Open and Comminuted Fractures (Sangeorzan III)

Principles

• Open fractures — urgent debridement, intravenous antibiotics, tetanus cover, and temporary spanning external fixation if definitive soft-tissue cover or reduction is not achievable at the first sitting. Definitive ORIF once the soft-tissue envelope recovers.
• Severe comminution where internal fixation is non-viable — consider primary arthrodesis of the destroyed talonavicular or naviculocuneiform joint, or a spanning external fixator to maintain medial column length, converting to delayed fixation/arthrodesis.

Soft-tissue Respect

The thin dorsal skin and the watershed blood supply make repeated aggressive approaches hazardous. Plan a single, well-executed exposure, preserve soft-tissue attachments, and use spanning fixation to rest the envelope when it is compromised.