Radial head fracture

In addition to the fracture itself, around 30% of cases are associated with other bone or soft tissue lesions. Ligament lesions are frequently observed, the lateral collateral ligament being the most frequently affected, with its lesion visible in up to 80% of cases on MRI. Injury to the medial collateral ligament is also possible. A specific entity is the Essex-Lopresti lesion, characterized by fracture of the radial head and damage to the distal radioulnar joint (DRUJ) and interosseous membrane. Other combinations of bone lesions and dislocation are also possible, such as fractures of the coronoid process, fractures of the olecranon, Monteggia’s dislocation fracture (fracture of the proximal ulna and dislocation of the radial head) and the terrible triad (fractures of the radial head and ulnar coronoid process and dislocation of the elbow). Radial head fractures may also be associated with carpal fractures such as scaphoid fractures.

Common symptoms include pain and tenderness along the lateral aspect of the elbow, often accompanied by limited mobility of the elbow or forearm, particularly supination and pronation. On physical examination, inspection may reveal bruising and swelling in the affected area. Pain on palpation at the side of the elbow is common, and in the case of associated dislocation, deformity may be visible. It is important to assess the presence of possible mechanical blockages of the elbow, evaluating both flexion/extension and pronation/supination. Normal ranges of motion for flexion/extension are generally 0-150°, while normal pronation and supination are 85° and 75° respectively. Needle aspiration of a joint hematoma and injection of a local anesthetic can help assess mechanical blockages. Stability tests are also crucial. For the elbow, the posterolateral drawer test and posterolateral pivot test can assess the lateral ulnar collateral ligament, while the valgus stress test is used to assess the medial collateral ligament. DRUJ can be assessed by palpating the wrist for pain and observing any abnormal translation in the sagittal plane by comparison with the other wrist. In cases where DRUJ involvement is difficult to determine, a dynamic CT scan may be performed. In addition, the interosseous membrane should also be palpated for pain, and during surgical management the radius traction test may indicate longitudinal forearm instability (Essex-Lopresti) if there is more than 3 mm of translation.

Imaging plays a crucial role in the assessment and diagnosis of radial head fractures. Radiographs are generally the initial imaging modality of choice. They help identify fractures, assess displacement or intra-articular involvement, and rule out concomitant forearm and wrist involvement. In some cases, the anterior or posterior fat pad sign may be present, indicating a minimally displaced occult fracture and intra-articular hemarthrosis. In some cases, a CT scan is indicated. It provides detailed information on complex fractures, particularly in comminuted fractures, and can also be useful for surgical planning.

Mason’s classification is a system used to categorize and describe different types of radial head fractures. It helps them understand the severity and complexity of the fracture, which guides treatment decisions. There are three main types of fracture:

• Type I: This is the least severe type of fracture, generally a small crack in the radial head, with no or only minimal displacement. Patients generally have no mechanical blockage.
• Type II: Involves displacement of the fragments. Patients may present with mechanical blockage.
• Type III: Involves multiple fragments and/or fragment displacement. In this case, patients almost always present with a mechanical blockage.
• Type IV: When the fracture is associated with elbow dislocation.

The therapeutic approach may be surgical or conservative. Non-operative treatment generally involves a short period of immobilization, usually lasting from 3 to 7 days, followed by early initiation of range-of-motion exercises. This approach is generally indicated for isolated, minimally displaced fractures without mechanical blocks (Mason I). Studies have shown favorable results, with good outcomes observed in around 85% to 95% of patients. However, it is important to be wary of potential complications, such as elbow stiffness, which may result from prolonged immobilization. To mitigate the risk of stiffness, early initiation of range-of-motion exercises is essential to restore functional mobility and prevent joint contractures.

Surgical intervention may be considered for more complex or displaced fractures, with other associated lesions, or those causing persistent pain or functional impairment despite conservative management. The choice of surgical approach depends on a number of factors, including fracture type, associated lesions, patient age and functional requirements.

Open reduction and osteosynthesis is one approach. It is indicated for Type II Mason fractures with mechanical block, Type III when the technique is feasible, and in the presence of other associated complex lesions. Various techniques can be used, including the use of screws alone or a combination of plates and screws, depending on the type of fracture and the surgeon’s preference. Results vary according to fracture type. Mason II fractures have shown good to excellent results in over 90% of cases. However, results for Mason III fractures are more variable. The number of fragments present in the fracture is an important factor influencing results. Studies have shown that this technique has poorer results when more than three fragments are present (over 50% unsatisfactory results) compared to cases with three fragments or less. This technique also shows equivalent results when comparing isolated fractures and complex fractures of the radial head (involving other fractures or dislocations). However, isolated fractures have better functional results and lower complication rates.

Partial excision of the radial head is an option generally considered for older, less demanding patients with complex fractures but no associated instability. In general, this technique is appropriate when the fragments are relatively small, constituting less than 25% of the radial head surface or 25 to 33% of the capitulum surface. This approach involves removing part of the fractured radial head rather than attempting to restore the anatomy. While this technique may offer advantages in some cases, it is essential to consider the potential risks, as even with excision of small fragments, there is a risk of instability. Removal of part of the radial head can disrupt the stability and biomechanics of the elbow joint, potentially leading to instability and functional limitations.

Complete excision of the radial head is an option generally reserved for sedentary patients who continue to experience pain at the site of an isolated lesion, at a distance from the traumatic event. This procedure involves the complete removal of the fractured radial head. While this may relieve pain in some cases, there are important contraindications to consider. The presence of destabilizing lesions, such as injury to the interosseous membrane of the forearm, fracture of the coronoid process and deficiency of the medial collateral ligament, are considered contraindications. These factors can contribute to joint instability and compromise overall elbow stability and function. Compared with other treatment options such as open reduction and osteosynthesis, this technique is associated with poorer results in terms of strength, function and movement. Patients may experience reduced grip strength, reduced range of motion and limitations in activities requiring rotational movements of the forearm. In addition, studies have shown a higher percentage of arthritis, with around 73% of patients developing arthritis in the affected elbow compared to the healthy elbow.

Arthroplasty is a viable alternative when other treatments such as open reduction and osteosynthesis, or radial head resection are unsuitable. This procedure involves replacing the damaged radial head with a prosthetic implant. Indications include complex fractures and cases where preservation of joint integrity and stability is essential: comminuted fractures (Mason type III) with more than three fragments, severe plastic deformation of the radial head, pseudarthrosis or callus, elbow fracture-luxation (terrible triad or variants of Monteggia’s dislocation fracture) involving more than 30% of the articular surface, and the Essex-Lopresti lesion (where excision of the radial head would exacerbate elbow/wrist instability and could lead to proximal radial migration and ulnocarpal impingement). By replacing the damaged radial head, elbow joint stability can be restored, preventing further complications and preserving joint function. Studies have shown good clinical results, and compared with osteosynthesis for fracture-luxations and type III Mason fractures, arthroplasty offers greater stability, lower complication rates and greater patient satisfaction. By maintaining the natural anatomy of the elbow joint, radial head arthroplasty provides improved joint mechanics and better long-term functional results.

Complications may arise, and must be taken into account prior to the management of radial head fractures. Surgical site infection is one possible complication. In less than 5% of conservatively treated fractures, secondary displacement may occur, and fixation may be necessary. Damage to the posterior interosseous nerve is a risk when the bicipital tuberosity is dissected distally during osteosynthesis, or when the radial neck is retracted too aggressively. In such cases, conservative management is usually initiated if neurapraxia is suspected, involving the use of a wrist splint. In cases where the nerve damage does not improve, electromyography may be performed and tendon transfer may be necessary. Elbow stiffness and loss of forearm rotation are common complications, with an incidence ranging from 3% to 20%. Risk factors include prolonged immobilization, intra-articular fracture, malunion/pseudarthrosis and heterotopic ossification. Non-operative management involves supervised exercise therapy with an elbow brace over a six-month period to achieve functional range of motion. Operative management may involve release of the contracture, with or without removal or replacement of the radial head, or allograft interposition arthroplasty of the anconeal muscle or Achilles tendon. Arthritis of the humero-radial joint may develop in the event of intra-articular fracture, or replacement of the radial head with a metal prosthesis. Treatment options include conservative approaches such as activity modification, anti-inflammatories and injections. Operative interventions may involve radial head resection or allograft interposition arthroplasty of the anconeal muscle or Achilles tendon. Heterotopic ossification is a potential complication, particularly in cases of central nervous system injury, burns or dislocated elbow fracture with significant soft-tissue damage. Preventive measures may include a six-week course of indomethacin (a non-steroidal anti-inflammatory drug) after a dislocation fracture, and although controversial, postoperative radiotherapy may be considered. Surgical removal of the ossification is an option, with generally satisfactory results, although recurrence may occur in around 10% of cases. Loss of hardware fixation is another possible complication that may require revision fixation, radial head replacement or radial head removal, depending on the specific circumstances.

It is therefore important to recognize and manage these potential complications to optimize outcomes and ensure treatment success. Regular monitoring, appropriate interventions and individualized treatment plans can help mitigate complications and improve outcomes for each patient.