27 Radius and Ulna Shaft Fractures
Fractures of the shaft of the radius and ulna (both bone forearm fractures) often occur from high-energy trauma, axial load injuries such as falls from height, and direct blows from protecting one’s face and head. Open injuries are also common and even small poke holes should be investigated to ensure an open injury is not missed. Tenets of treatment are anatomic restoration of the radius and ulna to restore the radial bow and forearm motion. Rigid internal fixation obviates the need for immobilization and allows for immediate motion to avoid stiffness (▶Video 27.1).
History and physical exam
Low energy—fall onto an outstretch arm.
High energy—motor vehicle collision, pedestrian struck.
Often seen when defending one’s face or head from oncoming trauma.
Forearm rotation—axis of rotation is from the radial head at the elbow to the ulnar head at the wrist (effectively the radius rotates around the ulna).
Radial bow and integrity of the interosseous membrane (IOM) are critical to maintain rotation of the forearm—central band, most important component of the IOM, if injured requires reconstruction. It acts as a “joint” in terms of importance of maintaining and restoring motion after an injury.
Orthogonal views of the elbow, forearm, wrist.
Consider computed tomography scan if there is extension into the elbow or wrist to evaluate the intra-articular involvement.
No widely accepted classification scheme is utilized.
Based most commonly on diaphyseal location (proximal one-third, mid one-third, distal one-third).
AO/OTA (anatomic) classification:
Bone – 2.
Midshaft – 2.
i. A – simple.
ii. B – wedge.
iii. C – complex.
Nightstick fracture—isolated ulnar shaft fracture.
Two categories—less than 50% displaced and more than 50% displaced. It can be successfully treated in a fracture brace if < 50% displaced.
Isolated radius fractures:
These are rare, and can be ballistic or a direct blow.
Not easily treated nonoperatively due to need for maintenance of the radial bow and preservation of forearm motion.
Beware of the “isolated” radius fracture as it may be a subtle Galeazzi injury.
Galeazzi injury (see Chapter 28, Distal Radius and Galeazzi Fractures, for additional information). Typically distal one-third radius shaft fracture with distal radioulnar joint (DRUJ) subluxation or dislocation.
Longitudinal injury to the IOM seen with radial head fractures and DRUJ injuries.
Associated with other injuries due to falls from height (i.e., lumbar spine injuries, calcaneus fractures, and femoral neck fractures).
Highly unstable injury.
Full primary survey.
Assessment of soft-tissue envelope.
Open versus Closed.
Assess for compartment syndrome:
Clinical exam is most reliable in an alert patient.
Consider compartment pressure monitoring in an obtunded patient (see Chapter 13, Acute Compartment Syndrome).
Evaluate for associated or distracting injuries.
Temporizing plaster splint immobilization.
Midshaft, distal third—sugar-tong splint.
Proximal third—sugar-tong splint and consider adding long arm extension.
Vast majority of forearm fractures are treated operatively due to the importance of maintaining forearm motion and preventing prolonged immobilization resulting in elbow and wrist stiffness.
Nondisplaced bony injuries with intact IOM can be treated nonoperatively, nightstick fractures < 50% displacement.
Dual incision approaches are preferred in both bone forearm fractures to avoid radioulnar synostosis.
Volar approach of Henry (▶ Fig. 27.1 )—utilitarian to radial shaft; can be extended proximally to the shoulder and distally to the wrist.
Incision can be extended from lateral to biceps tendon at the elbow flexion crease to the wrist lateral to flexor carpi radialis (FCR) tendon.
Incise fascia and develop the superficial interval by dissecting between brachioradialis (BR) and FCR distally, BR and pronator teres (PT) more proximally. Alternatively, the FCR tendon subsheath can be incised distally and FCR and flexor policis longus (FPL) are retracted ulnarly, giving access to pronator quadratus (PQ) and the distal radial shaft.
Internervous plane is BR (radial nerve) and PT (median nerve) proximally and FCR (median nerve) distally.
Superficial sensory branch of the radial nerve is on the undersurface of the BR and multiple recurrent leash vessels from the radial artery will need to be ligated or cauterized. The radial artery can be mobilized radially or ulnarly in the distal one-third of the forearm and is retracted ulnarly in the proximal two-third of the forearm.
Proximally—follow the biceps tendon to the biceps tuberosity to expose the proximal shaft.
Midshaft—pronate the forearm to expose the lateral insertion of the PT and release if needed to expose the midshaft of the radius.
Distally sweep FPL ulnarly and release PQ from the radial border of the radius and expose the distal shaft.
Dorsal approach of Thompson (▶ Fig. 27.2 )—often used for very proximal radial shaft exposure and open fractures.
Incision landmarks are from lateral epicondyle to Lister’s tubercle.
Incise fascia between extensor carpi radialis brevis (ECRB) and extensor digitorum communis (EDC).
Distally, the dissection plane changes to ECRB and abductor policis longus (APL).
Internervous plane is ECRB (radial) and EDC (posterior interosseous nerve [PIN]) and APL (PIN) distally.
Deep dissection focuses on finding and protecting PIN.
i. It is easiest to find the PIN distally as it exits the supinator muscle and dissect it proximally, protecting branches that innervate the supinator itself.
ii. Can also dissect from the proximal origin of the supinator and find the PIN proximally.
iii. PIN can be easily mobilized dorsally (ulnarly) and protected by supinating the forearm for midshaft and distal exposure.
iv. Pronate the forearm and mobilize the PIN volar (radial) when exposing the far proximal radius.
Full access to the dorsal radius is then achieved with subperiosteal dissection.
Direct approach to the ulnar shaft:
Skin incision along the subcutaneous border of the ulna.
Interval is between extensor carpi ulnaris (ECU) and flexor carpi ulnaris (FCU).
Internervous plane is ECU (PIN) and FCU (ulnar nerve), respectively.
Subperiosteal dissection or submuscular dissection is then performed to expose the ulna.
Of note, the dorsal or, less commonly, the volar aspect of the ulna shaft is typically exposed for plate location to avoid subcutaneous hardware prominence.
Fixation techniques (▶ Fig. 27.3 )
Anatomic reduction with lag screw fixation followed by volar neutralization plating.
Alternatively, primary compression plating without lag screw can be performed to achieve primary bone healing by creating an axilla in the plate.
3.5 mm compression plates are recommended and smaller or weaker plates should typically be avoided so as not to lose reduction with postoperative early motion.
Initial flexible fixation may be utilized with mini-fragment plates to hold reductions anatomic, if the proper trajectory for an independent lag screw is not feasible.
Useful if the injury cannot be reconstructed anatomically.
Avoid stripping in zone of injury.
Radial bow must be restored to allow for proper forearm motion.
i. Plate must sit eccentric if bow is properly restored (i.e., straight plate on a curved bone).
ii. Alternatively, precontoured plates that have a built in radial bow can be used. These can be helpful in highly comminuted injuries.
Ulnar bridge plating can be done percutaneously with small incisions away from the zone of injury.
Locking fixation—generally not necessary in the diaphysis of the forearm unless bone quality is poor or a short segment requires fixed-angle fixation (i.e., small radial neck fragment).
Devitalized bone should be thoroughly debrided and excised to avoid an infectious nidus.
Typically, acute bone grafting of bone defects in open fractures should be avoided due to risk for infection, although no definitive evidence supports this.
Antibiotic cement spacers or beads should be considered for planned staged bone grafting once the wound is sterile.
Most serious complication that can lead to Volkmann’s contracture.
i. Flexion contracture of the hand and wrist.
ii. Results in a claw-like deformity of the hand and digits.
Must have high clinical suspicion in closed and open injuries.
Fasciotomy should be performed from the carpal tunnel distally (including a carpal tunnel release) to the lacertus fibrosus proximally.
Vital structures at risk—radial artery, median nerve, lateral antebrachial cutaneous nerve, and superficial sensory branch of the radial nerve.
A volar compartment release may be sufficient in the majority of cases. Recheck dorsal and mobile wad compartments after volar release.
Seen most frequently in high-energy injuries with significant injury to the IOM, and injuries where both bones are approached through one incision.
Loss of forearm motion is the result.
Should be followed until maturity in a similar fashion as heterotopic ossification.
Can be resected (once mature) if symptomatic or limits function. Postoperatively, administer heterotopic ossification prophylaxis (radiation therapy or nonsteroidal anti-inflammatory drugs).
Most frequently seen in supination.
Initially treat with aggressive physical and occupational therapy.
Can be avoided if early motion is initiated.
Malunion can be avoided reliably if, after fixation is complete, intra-operative range of motion is compared to the contralateral forearm. If malreduction is suspected, the fracture length and rotation should be meticulously inspected to avoid permanent loss of motion.
Nonunion is rare (▶ Fig. 27.4 ).
i. Nonunion repair success rates are high.
ii. Treated with autogenous bone grafting and revision compression plating.
iii. If bone loss is present, induced membrane technique can be utilized with a staged approach using a cement spacer with subsequent autogenous cancellous or structural autografting.
Infection workup with inflammatory markers should be performed to rule out occult infection.
Adequate debridement should be performed and initiation of culture-directed antibiotic therapy.
Hardware can be retained if less than 6 weeks from surgery. Alternatively, hardware exchange can be performed to increase eradication of biofilm from the wound.
Seen mainly in open fractures.
Acute bone grafting is recommended as an option for comminution greater than one-third the diaphyseal circumference—no definitive data regarding safety of acute grafting in open fractures is available.
Staged bone grafting is an effective treatment option by utilization of the induced membrane technique.
If stable fixation is achieved and the soft-tissue envelope is amenable, only a soft dressing is necessary.
Immediate shoulder, elbow, forearm, wrist, and hand/finger motion should be initiated.
Immobilize in a splint for soft tissue rest if deemed necessary. Motion should be initiated as soon as the soft tissues allows.
Lifting restrictions are at the discretion of the surgeon:
Typically, weight-bearing as tolerated; although, some surgeons might limit weight-bearing for 4 to 8 weeks until there is radiographic evidence of healing.
Consider immediate weight-bearing for mobilization purposes in polytrauma patients.
Union rates are approximately 98%.
Functional outcomes are not well reported in large groups and highly dependent on type and severity of injury.
Studies with smaller groups have shown some degree of loss of grip and forearm strength, and a 10-degree loss of rotational forearm motion compared to contralateral forearm.