Both-Bone Forearm Fracture
Classification systems
- AO/OTA grouping for the radius and ulna diaphyses
- Descriptive by level, pattern and displacement, and by open or closed status
Mechanism
A fall onto the outstretched hand with a rotational component, a direct blow, or high-energy trauma. The forearm functions as a joint of rotation, so the injury is not simply two long bone fractures — restoring the radial bow, the relative lengths of the two bones and the interosseous space determines whether pronation and supination return.
Age considerations
- Paediatric
- Remodelling is good in the young child and closed reduction with an above-elbow cast in the appropriate rotation works well; the older child approaching maturity has less remodelling capacity and elastic nails or plating are used. Refracture after cast treatment is a recognised problem.
- Young adult
- Anatomical plate fixation of both bones is the standard, because the functional cost of malunion — lost rotation — is high. Compartment syndrome must be considered, particularly after high-energy or crush injury.
- Elderly
- Bone quality and the functional demand influence the construct and the aggressiveness of rehabilitation, but the principles of restoring rotation are unchanged.
Management options
Closed reduction and above-elbow cast (paediatric)showhide
Indication
Paediatric fractures with acceptable angulation and rotation and adequate remodelling potential.
Implant design notes
No implant. Well-moulded above-elbow cast with an interosseous mould and the forearm in the rotation that best maintains the reduction.
Approach
Non-operative under anaesthesia with fluoroscopic confirmation.
Steps overview
- Assess and document compartments and nerve function before and after reduction
- Reduce under anaesthesia with traction and correction of angulation and rotation
- Apply a moulded above-elbow cast with an interosseous mould, split if swelling is a concern
- Confirm alignment on both views before waking the patient
- Radiograph weekly for the first two to three weeks; loss of position is common
- Continue immobilisation for six weeks and warn about refracture risk after removal
Notes
Rotational malalignment does not remodel; angulation in the plane of motion partly does. Do not accept rotation in the hope of remodelling.
Resident summary compiled from standard orthopaedic trauma teaching; verify against your departmental protocol.
Plate fixation of both bonesshowhide
Indication
All displaced adult both-bone fractures, and paediatric fractures near maturity or with failed closed treatment.
Implant design notes
Small-fragment compression or locking plates giving absolute stability, restoring the radial bow precisely. The radius is usually plated volarly through the Henry approach, the ulna along its subcutaneous border. Undercontouring the radial plate loses the bow and costs rotation.
Approach
Volar Henry approach to the radius, developing the interval lateral to flexor carpi radialis and protecting the radial artery and the superficial radial nerve; direct subcutaneous approach for the ulna. Use two separate incisions to preserve the interosseous space and avoid synostosis.
Steps overview
- Supine with the arm on a hand table, tourniquet and fluoroscopy available
- Approach the radius volarly, protecting the radial artery medially and the posterior interosseous nerve proximally by supinating during proximal exposure
- Reduce the radius anatomically, restoring the radial bow, and fix with a compression plate
- Approach the ulna through a separate incision along its subcutaneous border
- Reduce and plate the ulna, restoring length so the distal radioulnar relationship is correct
- Check pronation and supination on the table and confirm both radiocapitellar and distal radioulnar relationships
- Avoid stripping the interosseous membrane and avoid bone debris in the interosseous space
- Close both wounds separately and begin immediate active rotation
Notes
Radioulnar synostosis is the specific complication of a single-incision or heavily stripped approach. Always check both ends of both bones before finishing.
Resident summary compiled from standard orthopaedic trauma teaching; verify against your departmental protocol.
Viva pearls
- Call the forearm a joint: the aim is restoration of rotation, so the radial bow, relative lengths and the interosseous space are the parameters that matter.
- Always examine and image both the elbow and the wrist — the Galeazzi and Monteggia patterns are what a single-bone film hides.
- Rotational malunion does not remodel in a child; do not accept it.
- Use two separate incisions and avoid bone debris in the interosseous space to reduce the risk of synostosis.
- Supinate the forearm during proximal radial exposure to move the posterior interosseous nerve away from the field.
- Consider compartment syndrome after high-energy or crush injury and after tight cast application.
Sources for further reading
- Rockwood and Green's Fractures in Adults — diaphyseal fractures of the radius and ulna
- Standard operative orthopaedics textbook — forearm fractures
- Regional anatomy text — volar approach to the radius and the posterior interosseous nerve
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Resident-authored study summary in original wording, not reproduced from copyrighted source text.