Paediatric Both-Bone Forearm Fracture — Flexible Intramedullary Nailing

Elastic stable intramedullary nailing (ESIN) is the operation of choice for a displaced both-bone diaphyseal forearm fracture in a child that cannot be held in an acceptable position by closed reduction and cast. It restores length, alignment and rotation while preserving the periosteal sleeve and avoiding the extensive exposure that plating demands. Absolute indications - Irreducible displaced both-bone diaphyseal forearm fracture after attempted closed reduction.

• Unstable pattern with greater than 50 percent translation or greater than 15 degrees angulation after reduction.
• Open both-bone fracture (Gustilo I to II) requiring debridement and stabilisation.
• Floating elbow injury (ipsilateral supracondylar humerus plus forearm fracture) with an unstable forearm segment.
• Neurovascular compromise requiring exploration and fracture stabilisation. Relative indications - Older child (greater than 10 to 12 years) approaching skeletal maturity where remodelling potential is limited.
• Failed closed reduction with unacceptable alignment on post-reduction radiographs.
• Polytrauma patient needing reliable fixation for early mobilisation and nursing care.
• Recurrent fracture or refracture of a previously healed forearm fracture. Acceptable for cast treatment (younger children) - Children younger than 8 to 10 years with acceptable closed reduction (less than 15 degrees angulation, less than 50 percent translation, maintained radial bow).
• Greenstick or plastic deformation patterns with good remodelling potential.
• Isolated radius or ulna fracture with acceptable alignment. Contraindications - Absolute: active infection at the planned entry sites; severe open fracture with segmental bone loss needing external fixation or other reconstruction; a patient too small for the available implant diameters (the nail must be at least 40 percent of the canal diameter).
• Relative: a skeletally mature adolescent, where plate fixation is preferred; severe comminution or a segmental pattern where length-stability cannot be achieved with nails alone.

Consent. Discuss the risk of superficial radial nerve injury (1 to 3 percent), compartment syndrome (1 to 3 percent), loss of rotation from a malreduced radial bow (5 to 10 percent), refracture after nail removal (5 to 10 percent), and the possible need to convert to a limited open reduction if closed nail passage fails.

The goal is to stabilise both bones with pre-contoured elastic nails that restore length, alignment and the radial bow, while protecting three structures at risk — the superficial radial nerve, the distal radial physis and the posterior interosseous nerve. The ulna is nailed first through a lateral antegrade entry to create a stable scaffold, then the radius is nailed retrograde through the radial metaphyseal border. Every step is done under fluoroscopy.

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Rehabilitation | Phase | Timing | Immobilisation & monitoring | Activity | |-------|--------|------------------------------|----------| | 1 | 0 to 2 weeks | Above-elbow cast in neutral rotation; strict elevation; compartment checks every 1 to 2 h for 24 h then every 4 h; weekly radiograph for the first 3 weeks | Finger active range of motion only | | 2 | 2 to 6 weeks | Removable thumb-free splint once callus appears | Gentle wrist and finger motion, scar care from 6 weeks | | 3 | 6 to 12 weeks | Below-elbow cast or removable splint | Progressive forearm rotation; light activity from 6 to 8 weeks | | 4 | After union (6 to 10 weeks) | Night splint for heavy tasks only | Strengthening; return to school with splint 8 to 10 weeks; contact sport after 3 to 4 months | | Nail removal | 6 to 12 months after union | Cast for 4 to 6 weeks post-removal; no contact sport for 3 months | Physeal-friendly timing; physiotherapy for any residual stiffness | Most children return to light activity by 6 to 8 weeks and to full contact sport once radiographic union and clinical strength have recovered, usually by 3 to 4 months. Elective nail removal is planned at 6 to 12 months after union and is followed by 4 to 6 weeks of cast protection because the empty canal behaves as a stress riser. Complications

Special circumstance — floating elbow injury. An ipsilateral supracondylar humerus fracture plus a both-bone forearm fracture leaves an unstable forearm segment at very high risk of compartment syndrome. Stabilise the forearm with flexible nailing first, then pin the supracondylar fracture; use prophylactic fasciotomy or extremely close compartment monitoring. The radial entry incision must be planned so it does not compromise the supracondylar pinning approach. Special circumstance — open both-bone fracture. Undertake urgent debridement and irrigation within 6 to 24 hours. Flexible nailing is acceptable for Gustilo I to II injuries after thorough lavage; leave the nail ends slightly prominent for easier later removal in the setting of infection. Give intravenous antibiotics for 24 to 48 hours (consider a prolonged oral course for Gustilo II) and use delayed primary closure or a negative-pressure dressing for larger wounds.

Relevant surgical anatomy. The radius carries a normal volar and radial bow of 15 to 20 degrees that is essential for full pronation and supination, while the ulna is relatively straight. Restoring this bow — not merely straight length — is the critical technical goal, so the nails are pre-contoured and the radial nail inserted with its apex oriented radially. The distal radial physis lies at the level of the radial styloid and Lister tubercle; the safe retrograde entry zone is the radial border of the metaphysis 1.5 to 2 cm proximal to the physis, which avoids the growth plate while providing adequate bone stock. The ulnar nerve passes posterior to the medial epicondyle and lies medial to the olecranon, so antegrade ulnar nailing uses a lateral starting point on the olecranon tip or proximal ulna to avoid the nerve entirely. The superficial radial nerve emerges from under the brachioradialis about 8 to 10 cm proximal to the radial styloid and courses subcutaneously along the radial border of the distal forearm — it is the structure most commonly injured in the procedure. The posterior interosseous nerve exits the supinator on the radial neck about 1 cm distal to the radial head, where an overly long radial nail can compress it. The interosseous membrane connects the two bones and divides the forearm into volar and dorsal compartments; both-bone fractures with significant displacement can produce compartment syndrome, the volar compartment most commonly affected. Why ESIN works, and the evidence for it. Elastic nailing maintains length, alignment and rotation while allowing early motion, carries a lower refracture rate than cast treatment in older children, and avoids the exposure and periosteal stripping required for plating; implant removal is then a simple day-case procedure. Meta-analyses and prospective series show greater than 90 percent excellent or good functional outcomes (Price criteria) when the radial bow and rotation are restored, with acceptable complication rates when the technique is meticulous — nerve injury less than 2 percent, compartment syndrome 1 to 3 percent and refracture 5 to 10 percent. Loss of the radial bow greater than 10 degrees is the strongest single predictor of a poor rotation outcome.