Radial Head Fractures: Open Reduction Internal Fixation



Radial Head Fractures: Open Reduction Internal Fixation


David Ring



The advent of techniques and implants for internal fixation of small fractures (1) coincided with an increasing appreciation of the important contributions of the radial head to the stability of the elbow and forearm (2,3,4,5). As a result, and also due to the inadequacy and problems associated with the silicone rubber radial-head prostheses (2,6,7,8), it became popular to attempt to save even the most complex fracture of the radial head by operative fixation (9). Early reports of open reduction and internal fixation (ORIF) of radial head fractures were very positive, perhaps due to the prevalence of isolated, partial, radial-head fractures for which good results would be expected (10,11,12,13,14,15). Some subsequent reports have stated that complex fractures of the radial head are prone to early failure, nonunion, and poor forearm rotation after operative fixation (9,16,17,18). Combined with increased availability and use of more-predictable metal radial-head prosthesis for complex fractures of the radial head (19,20), the role of ORIF is being redefined.


Indications/Contraindications


Historical Background

For most of the last century, excision of the radial head was the only commonly used treatment for fractures of the radial head (21,22), and decision making was simple: excise or do not excise. If excision was elected, the entire head was resected because the results of partial head excision were usually poor (23,24,25,26). In the 1980s, with the advent of techniques and implants for the fixation of small fractures and articular fracture fragments, ORIF became a more viable option (1).

On one hand, the incidence, severity, and consequences of proximal migration of the radius after excision of isolated radial-head fractures have long been a source of debate (24).
On the other hand, there is agreement on the value of retaining the fractured radial head amidst complex combined injury with instability of the forearm or elbow, such as an Essex-Lopresti injury (22,27) (radial head fracture and rupture of the interosseous ligament of the forearm) or a terrible triad injury (posterior dislocation of the elbow with fractures of the radial head and coronoid process) (28,29,30,31). The radial head is increasingly recognized as an important stabilizer of the forearm and elbow (2,3,4,5,22,28,29,30,31,32,33). Some authors even suggest that ulnohumeral arthrosis after elbow fracture-dislocation is accelerated in the absence of a radial head (34).

The initial reports of ORIF on radial-head fractures focused primarily on isolated fractures involving only part of the radial head (10,11,12,13,14,15). The good results in these series, the popularity of the new techniques for internal fixation of small fractures, and the increasing recognition of the importance of the radial head led many to emphasize the importance of preserving the native radial head. Unfortunately, subsequent papers have reported unpredictable results after internal fixation of more complex radial-head fractures (9,16,17,18), particularly very comminuted fractures with greater than three articular fragments (9).

Due to recent improvements in prostheses, surgeons are focused on deciding whether to use fixation or prosthetic replacement for radial head fractures associated with forearm and/or elbow instability. Problems related to the articulation of a metal radial-head implant with native capitular cartilage have been reported, but the majority of these problems are related to an oversized prosthesis (35). In general, results of prosthetic replacement of the radial head have been quite favorable (19,20), making it a useful alternative to ORIF.


Goals of Treatment

Fracture of the radial head can restrict forearm rotation, compromise the stability of the forearm or elbow, and in relatively rare cases, cause radiocapitellar arthrosis. The primary goal of treatment is to ensure forearm rotation. Incongruity of the radial head in the proximal radioulnar joint causes loss of rotation. Painful arthrosis of the proximal radioulnar joint is not usually observed. Although some studies dispute these observations, my training and experience lead me to conclude that partial fractures of the radial head that do not restrict forearm rotation are usually consistent with excellent elbow and forearm function no matter the radiographic appearance (13).

Operative fixation can restrict forearm rotation either via implant prominence, scarring, or heterotopic bone formation. Some patients with healed and apparently well-aligned fractures of the radial head after operative fixation have substantial loss of motion that is not attributable to implant prominence (9). This result may be due to articular incongruities, but based on observations of my own patients and similar observations noted in the literature (36), I suspect that many fractures of the radial head are impacted in a way that expands the diameter of the radial head. Healing of the radial head with this deformity might contribute to loss of forearm motion. Loss of ulnohumeral motion is usually related to capsular contracture and only rarely related to interference from displaced fracture fragments.

When the interosseous ligament of the forearm has been torn [the so-called Essex-Lopresti lesion (27) and variants (37,38)], the initial treatment must include restoration of contact between the radial head and capitulum to prevent marked proximal migration of the radius. Although restoration of the radial head does not guarantee good function in this complex injury, failure to restore the radial head will result in chronic forearm instability that currently has no good solution (39). Attempts to save the radial head at all costs might be unwise in this setting. For instance, many chronic Essex-Lopresti lesions result from failure of attempted operative fixation of the radial head. In this circumstance, where the radial head is essential, tenuous fixation of a complex radial-head fracture may be inadequate and prosthetic replacement might be preferable.

The circumstance is similar for elbow fracture-dislocations. Particularly for unstable elbow injuries, such as the terrible triad pattern of elbow fracture-dislocation (29), secure reconstruction of the radial head is requisite. If the fracture is too complex to achieve reconstruction, then radial head replacement may be preferable. Many partial radial-head
fractures are difficult or impossible to repair securely and should also be considered for prosthetic replacement.

Although radiographic criteria for acceptable alignment of the radial-head articular surface are frequently offered (24,31,40, 41), little data support them. The oft-repeated 2-mm limit for acceptable articular alignment, derived from Knirk and Jupiter’s study of intra-articular distal radius fractures (42), may not apply to the radiocapitellar joint. Although displaced fractures of the radial head are extremely common, radiocapitellar arthritis is an uncommon presenting complaint about which very little has been published (43).


Treatment Rationale According to Injury Pattern


Isolated Partial Radial-Head Fractures

Slightly displaced fractures involving part of the radial head do relatively well with nonoperative treatment (41,44). They rarely block motion, cause pain, or lead to arthrosis. Although radiographic criteria for operative treatment have been suggested, they lack scientific support.

One generally accepted indication for operative treatment of an isolated partial fracture of the radial head is a fracture that blocks forearm rotation. Because it can be difficult to assess forearm rotation in the setting of an acute, painful, elbow hemarthrosis, it can be useful to aspirate the hemarthrosis and place a local anesthetic in the elbow joint. Alternatively (perhaps preferably) if the patient is evaluated in the office at least 4 or 5 days after injury, the pain is sufficiently relieved to allow a reliable examination. Without block to motion, crepitation with forearm rotation does not seem predictive of problems, but this phenomenon deserves further study.

Because few problems arise with nonoperative treatment [a minimum of 75% good results in long-term follow-up as measured according to a very strict rating scale (45)], the surgeon should not take too much credit for good elbow function after operative treatment of isolated partial fractures of the radial head. In addition, operative treatment provides an opportunity for several complications and so should be undertaken with care.

Isolated fractures of the radial head that are more than slightly displaced are very uncommon (approximately 4% of all radial-head fractures in an unpublished review of over 300 patients treated at Massachusetts General Hospital). Among this small group of patients, blocks to forearm rotation were uncommon. The surgeon should therefore approach the management of the patient with an isolated partial fracture of the radial head with the understanding that these fractures rarely benefit from operative treatment.


Partial Radial-Head Fracture as Part of a Complex Injury

The treatment rationale for partial radial-head fractures that are part of a complex injury pattern is entirely different than in other cases. Such fractures are usually displaced and unstable with little or no soft-tissue attachments; occasionally some fragments are lost. Even a relatively small fracture can make an important contribution to the stability of the elbow and forearm. Usually, the anterolateral aspect of the radial head is fractured with resultant loss of the anterior buttress of the ulnohumeral joint.

While such fractures would seem to be obvious candidates for ORIF because the majority of the head remains intact, they can be very challenging to treat due to fragmentation, the small size of the fragments, lost fragments, poor bone quality, limited subchondral bone on the fracture fragments, and metaphyseal comminution and bone loss. Early failure of fixation of these fractures is potentially problematic, particularly in an Essex-Lopresti injury or a terrible triad fracture-dislocation of the elbow. Therefore, many partial-head fractures associated with complex injuries may be best treated with prosthetic replacement even though this means removing a substantial amount of uninjured radial head. ORIF is indicated when stable, reliable fixation can be achieved.

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Jun 13, 2016 | Posted by in ORTHOPEDIC | Comments Off on Radial Head Fractures: Open Reduction Internal Fixation
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