Tibial Intramedullary Nailing

Surgical Indications

Indications

• Diaphyseal (shaft) tibial fractures — the great majority of displaced closed fractures and many open fractures
• Unstable fracture patterns — those that fail to maintain acceptable alignment in a cast (shortening, angulation, rotation)
• Polytrauma / multiple injuries — to allow early mobilisation and reduce systemic complications
• Segmental fractures — where nailing spans both fracture levels with a single load-sharing device
• Most open tibial shaft fractures — after debridement and antibiotics; nailing is generally preferred over external fixation for definitive management of many open shafts

Relative Indications / Harder Cases

• Very proximal (metaphyseal) fractures — nail control is harder; consider suprapatellar entry, blocking screws, or plating
• Very distal (metaphyseal) fractures — limited distal segment for interlocks; multiplanar locking, blocking screws and fibular fixation help; plating is an alternative
• Fractures with intra-articular extension — may need supplementary screw fixation of the joint surface first

Contraindications

Absolute:

• Active sepsis at the entry site or within the canal
• Skeletal immaturity with open physes (risk to the proximal tibial physis from the entry point)

Relative:

• Severe contamination precluding internal fixation (consider temporary external fixation, then convert)
• Pre-existing deformity or a very narrow / obliterated medullary canal
• Patellofemoral pathology if a suprapatellar approach is planned (the portal traverses the patellofemoral joint)

Biomechanics of the Intramedullary Nail

• An IM nail is a load-sharing device positioned along the mechanical axis — it shares load with the surrounding bone, unlike a plate which is largely load-bearing
• Working length is the unsupported length of nail between the proximal and distal points of fixation across the fracture; a longer working length reduces bending and torsional stiffness, so reducing comminution gap and using a well-fitting nail matters
• A larger-diameter (reamed) nail has greater bending and torsional stiffness and allows larger interlocking screws
• Interlocking screws control length and rotation, converting the nail into a stable construct in unstable patterns

Reamed versus Unreamed Nailing

• Reaming enlarges the canal, allowing a larger, stiffer nail and more cortical contact; it deposits osteogenic reaming debris but transiently disrupts the endosteal blood supply (the periosteal supply, important in open fractures, is preserved)
• Closed fractures: reamed nailing is favoured — it reduces the rate of reoperation events compared with unreamed nailing (SPRINT)
• Open fractures: the SPRINT trial found NO significant difference between reamed and unreamed nailing — either is acceptable after debridement
• Practical compromise: ream to roughly 1-1.5 mm above the chosen nail diameter with sharp sequential reamers to balance fit against thermal and vascular insult

Approaches — Infrapatellar versus Suprapatellar

• Infrapatellar (traditional): knee flexed over a bolster; entry through the patellar tendon (transtendinous) or just medial to it (medial paratendinous). Familiar and quick, but the flexed-knee position and extensor pull predispose proximal-third fractures to apex-anterior and valgus deformity, and anterior knee pain is common
• Suprapatellar (semi-extended): the knee is in slight flexion ("semi-extended"); a portal is made through the quadriceps tendon and the nail instrumentation passes through the patellofemoral joint within a protective sleeve. The semi-extended position relaxes the deforming forces, makes imaging and reduction of proximal-third and segmental fractures easier, and avoids a transtendinous patellar tendon split. It requires a healthy patellofemoral joint and meticulous cartilage protection
• Randomised and pooled evidence comparing the two approaches shows the suprapatellar approach yields less anterior knee pain, better patellofemoral function and lower malalignment rates — it has gained popularity particularly for proximal and distal patterns

Key Evidence

Surface and Bony Anatomy

• The tibia is subcutaneous along its anteromedial border — a thin soft-tissue envelope that explains the frequency of open fractures and the importance of careful handling
• The proximal articular surface (tibial plateau) slopes posteriorly (posterior slope); on the lateral image the anterior down-slope of the plateau marks the correct sagittal entry
• The tibial tuberosity and patellar tendon are key surface landmarks for the infrapatellar approach; the quadriceps (suprapatellar) tendon and the patella are landmarks for the suprapatellar approach

The Entry Point (the most important single step)

• AP view: just MEDIAL to the lateral tibial spine — at the medial edge of the lateral tibial spine
• Lateral view: at the ANTERIOR margin of the articular surface, on the down-slope of the plateau (immediately adjacent to the articular cartilage)
• Entry that is too medial → valgus; too lateral → varus and lateral plateau injury; too posterior / too low → apex-anterior angulation and a posterior nail track
• The correct trajectory is collinear with the canal so the nail enters the diaphysis without levering the proximal fragment

Why Proximal-Third Fractures Deform

• In the proximal third the wide metaphysis gives the nail little endosteal contact, so the fragment is controlled by soft tissues, not the implant
• Deforming forces produce the classic apex-anterior (procurvatum) and valgus angulation:
  • The patellar tendon and extensor mechanism extend the proximal fragment (apex-anterior) when the knee is flexed for infrapatellar nailing
  • The pes anserinus and medial structures contribute to valgus
• Countermeasures: a sufficiently anterior start point, the semi-extended (suprapatellar) position, and blocking screws on the concave side

Neurovascular Structures at Risk

• Distal locking — superficial peroneal nerve: at risk with lateral-to-medial distal screws and percutaneous distal locking; use a careful open or "free-hand perfect-circle" technique and protect the soft tissues with a sleeve
• Posterior structures at the entry / proximal locking: the popliteal vessels lie posterior to the proximal tibia — avoid over-penetration posteriorly with guide wires and reamers
• Saphenous nerve / vein: along the medial leg, at risk during medial approaches and distal medial locking
• Suprapatellar approach — articular cartilage: the patellofemoral joint and trochlear cartilage are at risk; a protective sleeve and case selection (healthy PFJ) mitigate this

The Fibula in Tibial Fractures

• In distal-third tibial fractures, an associated fibular fracture allows the tibia to drift into valgus and shorten
• Plating the fibula first restores length and resists valgus, improving the reduction before tibial nailing — particularly useful when distal nail control is limited
• In mid-shaft fractures fibular fixation is usually unnecessary

Positioning and Preparation

Patient position: Supine on a radiolucent table. For infrapatellar nailing the knee is flexed roughly 90 degrees or more over a bolster/triangle to bring the tibial tuberosity into line; for suprapatellar nailing the knee is semi-extended (slight flexion, around 10-30 degrees) over a radiolucent ramp. Ensure the image intensifier can obtain true AP and lateral views of knee, shaft and ankle.

Anaesthesia and tourniquet: General or regional anaesthesia. A tourniquet may be applied but should ideally be deflated during reaming to reduce thermal necrosis. Give prophylactic antibiotics; for open fractures, antibiotics should already have been given early and the wound debrided.

Consent: Counsel specifically about anterior knee pain (common), malalignment (especially proximal/distal third), infection, nonunion/delayed union (higher in open and high-energy injuries), compartment syndrome, neurovascular injury (superficial peroneal nerve at distal locking) and hardware/locking failure or need for removal.

Step-by-Step Technique

Step 1: Examine, Reduce and Plan

Confirm the fracture pattern and level on full-length AP and lateral imaging. Assess the soft tissues and re-document the neurovascular and compartment status. Template nail diameter and length against the contralateral limb. Decide approach (infrapatellar versus suprapatellar) and plan blocking screws and distal locks for metaphyseal patterns.

Step 2: Make the Approach (Infrapatellar or Suprapatellar)

Infrapatellar: With the knee flexed, make a longitudinal incision from the inferior pole of patella to the tibial tuberosity. Split the patellar tendon in line (transtendinous) or retract it medially (medial paratendinous). Protect the fat pad.

Suprapatellar: With the knee semi-extended, make a longitudinal incision above the patella through the quadriceps tendon. Pass the protective cannula/sleeve through the patellofemoral joint down to the entry point, shielding the trochlear and patellar cartilage throughout.

Step 3: Establish the Entry Point

Place the guide wire at the correct start point — just medial to the lateral tibial spine on AP and at the anterior margin of the articular surface on lateral. Confirm BOTH views on the image intensifier before opening the cortex with the entry reamer or awl.

Step 4: Reduce the Fracture and Pass the Ball-Tipped Guide Wire

Reduce the fracture (traction, manual manipulation, and for metaphyseal fractures, planned blocking screws). Pass the ball-tipped guide wire across the fracture and centre it in the distal fragment on both views. Measure nail length over the guide wire.

Step 5: Ream the Canal

For reamed nailing, advance sharp sequential reamers over the guide wire, removing the reamer to clear debris between passes. Ream to roughly 1-1.5 mm above the planned nail diameter. Irrigate and avoid reaming with the tourniquet inflated to limit thermal injury.

Step 6: Insert the Nail

Pass the correctly sized nail over the guide wire across the fracture, maintaining reduction. Seat the nail so the proximal end is buried beneath the articular entry and the distal tip is appropriately positioned for distal locking. Recheck alignment on both views.

Step 7: Proximal Interlocking and Blocking (Poller) Screws

Insert proximal interlocking screws using the targeting jig. For proximal-third fractures, place blocking (Poller) screws on the concave side of the deformity to redirect the nail and lock in the correction. Recheck alignment.

Step 8: Distal Interlocking

Lock the nail distally using a free-hand "perfect-circle" technique under image intensifier. For distal-third fractures use at least two distal interlocks, ideally in different planes, for angular and rotational control. Protect the superficial peroneal nerve when placing lateral-to-medial screws.

Step 9: Fibular Fixation, Final Checks and Closure

For distal-third fractures with valgus instability, consider plating the fibula (often done before tibial nailing) to restore length and alignment. Perform a final assessment of alignment (length, rotation, angulation) and stability on both views, irrigate, and close in layers. Re-document the neurovascular and compartment status.

Post-operative Protocol

Early Phase (Day 0-14)

• Neurovascular and compartment checks: serial assessment in recovery and on the ward — a tibial nailing patient can still develop compartment syndrome post-operatively
• Analgesia: multimodal; remember that escalating analgesic requirement is a red flag for compartment syndrome, not simply "expected pain"
• Elevation and early mobilisation: elevate the limb to reduce swelling; begin early knee and ankle range of motion
• Weight-bearing: for stable, well-locked transverse/short-oblique diaphyseal fractures, early weight-bearing as tolerated is commonly permitted; for comminuted, segmental, or metaphyseal fractures, protected/partial weight-bearing is used until early callus appears
• Thromboprophylaxis: per local protocol given the lower-limb injury and reduced mobility

Rehabilitation and Follow-up

• Range of motion: knee and ankle ROM from early on; focus on regaining full knee extension/flexion and ankle dorsiflexion
• Progression of weight-bearing: advance as radiographic union progresses; dynamisation may be considered for delayed union in selected cases
• Radiographic follow-up: serial AP and lateral radiographs to confirm progression of union and detect loss of fixation or malalignment
• Counselling: reinforce that anterior knee pain may persist and that hardware removal is not a guaranteed cure

Return to Function

• Light activity / desk work: as comfort and mobility allow, often within a few weeks
• Manual work and sport: typically once the fracture has united and strength/proprioception are restored, often around 3-6 months depending on fracture and healing
• Nail removal: usually deferred until well after union (commonly beyond a year), and only if symptomatic — counsel that it may not relieve anterior knee pain

Special Case: Open Tibial Fractures

Principles

• Antibiotics early — ideally within an hour of injury; delay is associated with increased infection
• Tetanus prophylaxis as indicated
• Thorough surgical debridement of devitalised tissue and contamination BEFORE definitive fixation
• Definitive fixation: nailing is acceptable for many open shaft fractures after debridement; reamed and unreamed nailing show no significant difference in open fractures (SPRINT)
• Soft-tissue cover: plan combined orthoplastic management ("fix-and-flap") for high-grade injuries to achieve early definitive soft-tissue cover

Damage Control

• In the unstable polytrauma patient or grossly contaminated wound, temporary external fixation (damage control orthopaedics) may precede conversion to a nail once the patient and soft tissues allow

Special Case: Proximal- and Distal-Third Fractures

Proximal Third

• Deforms into apex-anterior and valgus — use the semi-extended/suprapatellar approach, a correct (anterior-enough) start point, and blocking screws on the concave side
• Confirm alignment carefully on the lateral view, where procurvatum is easily missed

Distal Third

• Limited distal segment for fixation — use at least two, ideally multiplanar, distal interlocks, blocking screws, and consider fibular plating to restore length and resist valgus
• Plating is a reasonable alternative when nail control is inadequate or there is significant intra-articular extension