Radial head fractures are common and are the most common elbow fractures. They usually arise from a fall on the outstretched hand with the elbow slightly flexed and pronated. A direct impact may also cause the radial head to fracture.
Radial head fractures can be isolated or as part of a more complex elbow fracture pattern.
The patient will complain of pain and decreased range of motion. When specifically asked they will typically recall only mild pain or discomfort with a good range of motion directly after the fall, progressing to more severe pain and stiffness in the next 20 to 30 minutes. This is caused by the haemarthrosis that develops and progressively stretches the well-innervated capsule. The haemarthrosis limits motion by its volume and by the pain caused from stretching the capsule.
The haemarthrosis will cause a swelling at the posterolateral aspect of the elbow, visible at inspection. The medial side is inspected for a haematoma, indicative of medial collateral ligament damage. Flexion and extension are decreased due to pain, caused by further stretching of the capsule. Pronation and supination may be painful and decreased.
It is important to differentiate between a decreased range of motion mediated by pain or a true mechanical block to rotation, by displacement of the fragments or cartilage interposition in the fracture.
The radial head will be painful to palpation. Pressure on the radial head, while the forearm is rotated may accentuate this pain. The forearm may be painful in the case of an interosseous membrane lesion.
The wrist is examined with special interest for the distal radioulnar joint and the scaphoid bone, as this may have fractured at the time of injury.
Plain radiographs are usually sufficient to diagnose a radial head fracture (Figure 1). Non-displaced fractures are often not readily visible but a posterior fat pad sign is pathognomonic for a haemarthrosis and an indirect sign of a non-displaced radial head fracture. Computed Tomography (CT) scans are commonly used in the workup of radial head fractures. Associated lesions are common and can become apparent on the CT images (Figure 2). CT is also very helpful to quantify fragment displacement and the number of fragments.
The Mason classification is most commonly used. Radial head fractures are classified based on number of fragments and displacement. In type 1 fractures, the fragments are not displaced. In type 2 fractures fragments are displaced more than 2 mm and a comminuted fracture is classified as a type 3 fracture. The more recent Mayo classification includes the same three types of fractures but includes a suffix for the very common associated lesions that often define the treatment.
Non-displaced fractures are treated conservatively. Aspiration of the haematoma will relieve the pain and immediately increase motion. A local anesthetic can be injected into the joint if a block to rotation is present. Pronation and supination are repeated to evaluate if it is a true mechanical block or if the decreased range of motion is pain-mediated. A sling can be worn for comfort and the patient is advised not to load the forearm for 6 weeks. The patient is encouraged to mobilize the elbow immediately. Plain radiographs are repeated at 1 and 2 weeks post-trauma to evaluate secondary displacement. A final radiograph is taken at 6 weeks at which time the fracture is usually healed and all activities of daily living can be resumed. Results of this approach are generally excellent.
Indications for Surgery
A mechanical block to motion, as well as displacement of the fracture fragments, are indications for surgery in isolated radial head fractures. It is not uncommon for an associated fracture of, for example, the proximal ulna to be the indication for surgery. In these cases the radial head fracture should be evaluated for stability of the fragment and it may be indicated to fix a radial head fracture, even if there is minimal displacement.
Depending on the type of fracture, radial head fractures can be approached through an open or an arthroscopic technique. Displaced type 2 fractures may be treated arthroscopically, depending on the surgeon’s experience with this technique. Comminuted or grossly displaced fractures are best treated with an open technique.
Both techniques will be discussed below.
General anesthesia, standard 4.5 mm scope and arthroscopic equipment, tourniquet control, lateral decubitus
Sterile preparation of the skin and draping
Palpate ulnar nerve and bony landmarks and mark relevant anatomy on the skin
Insufflate the joint with saline
Anteromedial viewing portal
Insert the scope and use a needle to establish the lateral portal
Wash out the fracture hematoma and any loose osteochondral fragments
Inspect the fracture (Figure 3), the coronoid process and lateral soft tissues, including the lateral collateral ligament (LCL)
Reduce the fracture with a probe from the lateral portal
Rotate the forearm to facilitate reduction
If adequate reduction is obtained, a guide wire can be drilled percutaneously or through the lateral portal depending on the location of the fracture. This step can also be, and is often, performed later in the procedure, with a view posteriorly from the radiohumeral gutter.
Measure the length of the screw and overdrill the guidewire with a cannulated drill bit.
Fix the radial head with a cannulated headless screw. Remove the guidewire and evaluate the stability of the fixation. A second screw can be used if necessary.
Posterolateral viewing portal
Inspect the posterior compartment, including the ulnar gutter and olecranon tip and fossa. Evaluate medial stability with valgus stress.
Washout the posterior compartment and remove any debris
Place the scope in the radiohumeral gutter
Use a needle to establish the soft spot portal. Washout the radiohumeral gutter and remove any debris.
Inspect the fracture reduction and fixation. If the fracture was not yet fixed earlier, the same steps apply, until stable fixation is obtained.
Open approach to radial head fractures
General or regional anesthesia, tourniquet control, supine position with arm on armtable, elbow in 70 degrees of flexion and pronation
Sterile preparation of the skin and draping
Lateral curved incision, 4 cm, centered on radial head and lateral epicondyle, following the lateral humeral ridge.
Palpate the LCL. Even when it is avulsed from the lateral epicondyle, it is usually still palpable.
Extensor tendon split on the anterior edge of the LCL. Alternatively, a Kocher approach can be used but this is not my preference.
Evaluate the integrity of the LCL and Incise the anular ligament anterior to the lateral ulnar collateral ligament
Evacuate the fracture haematoma and washout the joint
Reduce the fracture and fix with headless screws
If the neck is involved we prefer to do a low profile fixation with headless screws from the head into to neck. In some cases, a radial neck plate may be needed to achieve adequate fixation.
In cases with severe comminution, fragments are removed and stability is evaluated by applying a valgus stress to the elbow
The radial pull test is used to evaluate longitudinal instability of the forearm
We prefer to replace the radial head by a metallic prosthesis but a radial head resection may be an option if the elbow and forearm are stable
Placement of the radial head prosthesis depends on the system used
The height of the prosthesis is crucial and should be level with the proximal edge of the lesser sigmoid notch, when the forearm is in neutral position (Figure 4).
If the LCL was avulsed it should be reinserted (Figure 5). This can be done using bone tunnels and transosseus fixation or by using a bone anchor to fix the ligament.
The extensor tendon split is closed to the LCL to provide extra strength to the lateral structures
A dynamic external fixator can be used if the elbow is unstable following bony reconstruction of all fractures and repair of the ligaments. This is almost never indicated for isolated radial head fractures.
Pearls and Pitfalls of Technique
Avoid immobilization of non-displaced fractures. Early mobilization does not increase the risk of displacement of the fragments and decreases the risk of stiffness.
Always evaluate the posterior aspect of the capitellum with the arthroscopic technique. Osteochondral lesions are common and fragments may cause symptoms.
Use an extensor tendon split approach to the radial head instead of Kocher’s interval. This allows for improved visualization of the radial head and avoids damaging the LCL. The anterior capsule can be released from the extensor tendon split. This greatly increases the view and workspace.
Fluoroscopic evaluation of the length of the screws can be deceiving. Always rotate the forearm after placement of the screws and be aware of crepitus or scraping.
Over- or under-lengthening of the radius with a prosthesis will decrease the chances of a good result. Use the lesser sigmoid notch on the proximal ulna as a landmark, as the radiohumeral relationship may be disturbed.
Potential complications specific to the arthroscopic technique include injury to neurovascular structures. Marking the ulnar nerve on the skin, insufflating the joint, and experience with elbow arthroscopy all decrease the risk of nerve damage.
Increased swelling of the forearm and elbow can lead to decreased range of motion and theoretically there is a risk of compartment syndrome of the forearm. Low pressure of the pump or saline bags, as well as minimizing the operating time will decrease the occurrence of swelling.
With regards to the open technique, iatrogenic injury to the LCL can be avoided by using an extensor split approach.
Impingement of hardware and malorientation or placement of a prosthesis should be avoided. Standard antibiotic prophylaxis will decrease the risk of an infection.
Stiffness is common and strong fixation of fragments is necessary as this should allow for early mobilization.
Associated lesions will often dictate the post-operative rehabilitation, but if at all possible, the elbow should be mobilized immediately. Short immobilization may be indicated for comfort but should not exceed 1 week.
In cases of ligamentous repair we prefer to use a dynamic elbow brace. Full flexion is permitted but extension is blocked from 60 degrees for the first 2 weeks. Between 2 and 4 weeks extension is permitted to 30 degrees and between 4 and 6 weeks both flexion and extension are free. The brace is discontinued after 6 weeks.
Outcomes/Evidence in the Literature
van Riet, RP, Morrey, BF, O’Driscoll, SW, Van Glabbeek, F. “Associated injuries complicating radial head fractures: a demographic study”. Clin Orthop Relat Res. vol. 441. 2005. pp. 351-5. (Adult radial head fractures were evaluated for associated lesions. Mean age was 45 years. Gender ratio was approximately 1:1. Men were on average 7 years younger at the time of injury and sustained more severe injuries. About 67% of patients had a type 1 radial head fracture, 14% had a type 2, and 19% had a comminuted, type 3 fracture. Eight percent of type 1, 50% of type 2, and 75% of type 3 fractures had associated injuries. Associated fractures were common, with coronoid fractures as the most common associated fracture at the elbow. Clinically significant lateral and/or medial collateral ligament ruptures were found in 11% of patients but these injuries were shown to remain subclinical in many other patients. The radial head fractured as part of an elbow dislocation in 14% of patients. Not surprisingly, associated injuries were found to be more common in more severe injuries to the radial head.)
Holdsworth, BJ, Clement, DA, Rothwell, PN. “Fractures of the radial head–the benefit of aspiration: a prospective controlled trial”. Injury. vol. 18. 1987. pp. 44-7. ((This classic paper first showed the benefit of aspiration and early motion versus immobilization.)
Chalidis, BE, Papadopoulos, PP, Sachinis, NC, Dimitiou, CG. “Aspiration alone versus aspiration and bupivacaine injection in the treatment of undisplaced radial head fractures: A prospective randomized study”. vol. 18. 2009. pp. 676-9. (Aspiration alone offers significant decrease in pain and facilitates early motion of the elbow in type 1 fractures. The use of a local anesthetic did not further improve the results. Local anesthetic may also have a detrimental effect on articular cartilage. With this in mind and the lack of data showing a significant improvement over aspiration alone, in my opinion the use of local anesthetic is not indicated, unless the anesthetic is administered in order to evaluate a mechanical block to motion.)
Ring, D, Quintero, J, Jupiter, JB. “Open reduction and internal fixation of fractures of the radial head”. J Bone Joint Surg Am. vol. 84-A. 2002. pp. 1811-5. (The authors present the results of 56 surgically treated patients with type 2 and 3 radial head fractures. Failure of fixation or nonunion was shown to result in poorer results. The authors concluded that removal of the radial head, with or without radial head replacement, instead of open reduction internal fixation, is probably indicated in fractures with more than three fragments and when the radial head is fractured as part of a more complex injury pattern, potentially compromising fracture healing.)
Michels, F, Pouliart, N, Handelberg, F. “Arthroscopic management of Mason type 2 radial head fractures”. Knee Surg Sports Traumatol Arthrosc. vol. 15. 2007. pp. 1244-50. (The authors present the results of 14 patients treated with arthroscopically-assisted reduction and internal fixation of type 2 radial head fractures. Results were good to excellent in all 14 patients. The authors identify the evaluation and potential treatment of associated intra-articular lesions as one of the advantages of this technique.)
Caputo, AE, Mazzocca, AD, Santoro, VM. “The nonarticulating portion of the radial head: anatomic and clinical indications for internal rotation”. J Hand Surg Am. vol. 23. 1998. pp. 1082-90. (This paper is a must read for any surgeon who surgically treats radial head fractures. The authors showed a non-articulating portion of 113 degrees and found a correlation of this non-articulating portion with the location of Lister’s tubercle. As a guideline, palpate Lister’s tubercle and transfer this to the radial head. Hardware can be placed at an arc of 90 degrees with this mark at the center, without causing impingement.)
Smith, AM, Urbanosky, LR, Castle, JA, Rushing, JT, Ruch, DS. “Radius pull test: predictor of longitudinal forearm stability”. JBJS-A.. vol. 84-A. 2002. pp. 1970-6. (Symptomatic longitudinal radioulnar disscociation following radial head resection is extremely difficult to treat and results are disappointing. The authors describe a test to avoid this problem. If the test is positive, radial head reconstruction with osteosynthesis or prosthetic replacement is absolutely indicated. Radial head fragments are resected and a Kocher clamp is attached to the proximal radial stump. The radius is then simply pulled proximally and the amount of translation is measured. An interosseus membrane rupture can be suspected with a translation of as little as 3 mm. A rupture of all longitudinal stabilizers will lead to a translation of more than 6 mm.)
van Riet, RP, Van Glabbeek, F, de Weerdt, W, Oemar, J, Bortier, H. “Validation of the lesser sigmoid notch of the ulna as a reference point for accurate placement of a prosthesis for the head of the radius: a cadaveric study”. JBJS-Br. vol. 89. 2007. pp. 413-6. (In this anatomical study, the proximal edge of the lesser sigmoid notch was shown to correspond with the height of the radial head. This study offers an important landmark to assess the height of a radial head replacement in the clinical setting.)
Zwingmann, J, Welzel, M, Dovi-Akue, D, Schmal, H, Sudkamp, NP, Strohm, PC. “Clinical results after different operative outcome methods of radial head fractures: A systematic review and meta-analysis of clinical outcome”. Injury. vol. 44. 2013. pp. 1540-50. (Out of a total of 851 clinical papers on radial head fractures a final 58 papers were included in this review and meta-analysis. One thousand, two hundred and sixty-four patients were included at an average follow-up of 67.5 months. The authors concluded that open reduction and internal fixation had the best results for type 2 radial head fractures. The same was concluded for type 3 fractures on the premise that stable fixation is possible and that the choice between open reduction and internal fixation, resection or radial head replacement should be made intra-operatively to avoid late complications such as instability, pseudoarthrosis, and displacement of fragments.)
van Riet, RP, Sanchez-Sotelo, J, Morrey, BF. “Failure of metal radial head replacement”. JBJS-Br. vol. 92. 2010. pp. 661-7. (A metal radial head replacement was removed in 47 patients for a variety of reasons. The most common reason was painful loosening of the prosthesis. Other reasons included stiffness, instability, and infection. Radiographic signs of overlengthening were found in 11 out of 47 patients and all but one patient had degenerative changes at the elbow.)
Radial head fractures are common. Results of treatment are good. Radial head fractures are classified into one of three types. Associated lesions are added as a suffix. Isolated type 1 fractures are treated conservatively by aspirating the joint and mobilizing the elbow as pain allows. Displaced type 2 fractures are treated by reduction and fixation of fragments. This can be done via an arthroscopic or an open technique. Comminuted type 3 fractures are treated with resection of the fragments and placement of a radial head prosthesis. Radial head resection is an option in patients with a stable elbow and forearm but care should be taken, as associated lesions are common. Long term immobilization of the elbow should be avoided at all cost and a hinged dynamic elbow brace can be used if the repair of ligamentous structures needs to be protected.
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- The Problem
- Clinical Presentation
- Diagnostic Workup
- Non–Operative Management
- Indications for Surgery
- Surgical Technique
- Pearls and Pitfalls of Technique
- Potential Complications
- Post–operative Rehabilitation
- Outcomes/Evidence in the Literature