DEFINITION

Radial head fractures are the most common fracture of the elbow and usually can be managed either nonoperatively or with open reduction and internal fixation (ORIF).12

Radial head arthroplasty is indicated for unreconstructable displaced radial head fractures with an associated elbow dislocation or a known or possible disruption of the medial collateral, lateral collateral, or interosseous ligaments.26

Most comminuted radial head fractures have an associated ligament injury, so radial head excision without replacement is uncommonly indicated in the setting of an acute radial head fracture.

Biomechanical studies have shown that the kinematics and stability of the elbow are altered by radial head excision, even in the setting of intact collateral ligaments,24 and are improved with a metallic radial head arthroplasty.6,31,39

Radial head replacement is also indicated to treat posttraumatic conditions such as radial head nonunion and malunion and to manage elbow or forearm instability after radial head excision.41

 

 

ANATOMY

 

The radial head has a circular concave dish that articulates with the spherical capitellum and an articular margin that articulates with the lesser sigmoid notch of the ulna.

 

The articular dish has an elliptical shape that varies considerably in size and shape and is variably offset from the axis of the radial neck.44

 

There is a poor correlation between the size of the radial head and the medullary canal of the radial neck, making a modular implant desirable for an optimal fit.30

 

Elbow stability is maintained by joint congruity, capsuloligamentous integrity, and an intact balanced musculature.

 

The radial head is an important valgus stabilizer of the elbow, particularly in the setting of an incompetent medial collateral ligament, which is the primary stabilizer against valgus force.

 

The radial head is also important as an axial stabilizer of the forearm and resists varus and posterolateral rotatory instability by tensioning the lateral collateral ligament.25

 

The lateral ulnar collateral ligament is an important stabilizer against varus and posterolateral rotational instability of the elbow37 and should be preserved or repaired after radial head arthroplasty (FIG 1).

 

The radial head accounts for up to 60% of the load transfer across the elbow.19

 

PATHOGENESIS

 

Displaced radial head fractures typically result from a fall on the outstretched arm.

 

Axial, valgus, and posterolateral rotational patterns of loading are all thought to be potentially responsible for these fractures.

 

Injuries of the medial collateral or lateral collateral ligament or the interosseous ligament are typically associated with comminuted displaced unreconstructable radial head fractures.9

 

In more severe injuries, dislocations of the elbow and forearm and fractures of the coronoid, olecranon, and capitellum can occur and further impair stability.

 

NATURAL HISTORY

 

Long-term follow-up studies suggest a high incidence of radiographic arthritis with radial head excision, although the incidence of symptomatic arthritis varies widely between series.7,22,23

 

Biomechanical data have demonstrated an alteration in the kinematics, load transfer, and stability of the elbow after radial head excision6,24 that may lead to premature cartilage wear of the ulnohumeral joint and secondary pain due to arthritis.

 

 

 

FIG 1 • The ligaments on the lateral aspect of the elbow include the lateral ulnar collateral ligament, the radial collateral ligament, and the annular ligament. The lateral ulnar collateral ligament is an important stabilizer against varus and posterolateral rotational instability of the elbow and should be preserved or repaired after radial head arthroplasty.

 

 

P.4021

 

Metallic radial head replacement in elbows with intact ligaments restores the kinematics and stability similar to that of a native radial head and has been shown to provide good clinical and radiographic outcome in most

patients at medium-term follow-up; however, long-term outcome studies are lacking.6

PATIENT HISTORY AND PHYSICAL FINDINGS

 

The mechanism of injury is typically a fall on the outstretched hand.

 

 

The patient will complain of pain and limitation of elbow or forearm motion. A history of forearm or wrist pain should be sought.

 

Inspection may reveal ecchymosis along the forearm or medial aspect of the elbow. Deformity may be evident if there is an associated dislocation.

 

Careful palpation of the radial head, the medial and lateral collateral ligaments of the elbow, the interosseous ligament of the forearm, and the distal radioulnar joint should be performed. Local tenderness over one or all of these structures implies a possible derangement of the relevant structure.

 

Because associated injuries of the shoulder, forearm, wrist, and hand are common, these areas should be carefully examined.

 

Range of motion, including forearm rotation and elbow flexion-extension, should be evaluated. The presence of palpable and auditory crepitus should be noted.

 

Loss of terminal elbow flexion and extension is expected as a consequence of a hemarthrosis in acute fractures, whereas loss of forearm rotation typically is caused by a mechanical impingement.

 

A careful neurovascular assessment of all three major nerves that cross the elbow should be performed.

 

The examiner should observe for localized or diffuse swelling in the elbow. Effusion represents hemarthrosis due to intra-articular fracture.

 

The examiner should compare active and passive range of motion to the uninjured side. Reduced range of motion may be a result of hemarthrosis or mechanical block from a broken fragment. Intra-articular injection of a local anesthetic helps differentiate between reduced range of motion due to a mechanical block versus pain inhibition.

 

The examiner should look for varus-valgus instability. Any gapping on the medial or lateral side beneath the examiner's hand is noted. Positive findings suggest medial or lateral collateral ligament insufficiency. Typically, this test is positive only when performed under a regional or general anesthetic, hence these injuries are easy to miss if an examination under anesthesia is not performed.

 

The lateral pivot shift test is performed. Positive apprehension or a clunk that is seen or felt when the ulna and radius reduce on the humerus suggests posterolateral rotatory instability.

 

IMAGING AND OTHER DIAGNOSTIC STUDIES

 

Anteroposterior (AP), lateral, and oblique elbow radiographs, with the x-ray beam centered on the radiocapitellar joint, usually provide sufficient information for the diagnosis and treatment of radial head fractures.

 

Bilateral posteroanterior radiographs of both wrists in neutral rotation should be performed to evaluate ulnar variance in patients with wrist discomfort or a comminuted radial head fracture because there is a higher

incidence of an associated interosseous ligament injury in these patients.9

 

Computed tomography with sagittal, coronal, and threedimensional (3-D) reconstructions may assist with preoperative planning and can help the surgeon predict whether a displaced radial head fracture can be repaired with ORIF or if an arthroplasty will likely be needed.

 

DIFFERENTIAL DIAGNOSIS

 

Acute radial head fractures

Other fractures or dislocations about the elbow (eg, supracondylar, capitellar, coronoid, osteochondral fractures)

Radial head nonunion or malunion, posttraumatic arthritis Congenital dislocation of the radial head

Forearm or elbow instability Lateral epicondylitis

Rheumatoid arthritis or osteoarthritis Synovitis, inflammatory or infectious Tumors

 

 

NONOPERATIVE MANAGEMENT

 

The indications for surgical management of radial head fractures are not well defined in the literature. Fragment size, number of fracture fragments, degree of displacement, and bone quality influence decision making regarding the optimal management.

 

Nondisplaced fractures or small (<33% of the radial head) minimally displaced fractures (<2 mm of displacement) can be treated with early motion with an excellent outcome in the majority of patients.21

 

Associated injuries and a block to motion are also important factors to consider when deciding between nonoperative and surgical management.

 

SURGICAL MANAGEMENT

 

Small displaced fractures that cause painful crepitus or limited motion are managed with fragment excision if they are too small (typically, <25% of the diameter of the radial head) or osteopenic to be internally fixated.

 

Larger displaced fractures are typically managed with ORIF with good outcomes in most patients.35,46

 

Radial head fractures that are displaced but too comminuted to be anatomically reduced and stably fixed and that are too large to consider fragment excision (involve more than a quarter to a third of the radial head) should be managed by radial head excision with or without arthroplasty.1,27

 

Patients who are known to have, or are likely to have, an associated ligamentous injury of the elbow or forearm should have a radial head arthroplasty because radial head excision is contraindicated (FIG 2).29

 

The decision as to what fracture is reconstructable depends on surgeon factors (eg, experience), patient factors (eg, osteoporosis), and fracture factors (eg, fragment number and size, comminution, associated soft tissue injuries). The final decision is often made only at the time of surgery.

 

Other indications for radial head arthroplasty include radial head nonunion or malunion, primary or secondary management of forearm or elbow instability (eg, Essex-Lopresti injury), rheumatoid arthritis or osteoarthritis, and tumors.

 

 

P.4022

 

 

 

FIG 2 • A,B. AP and lateral radiographs of a 54-year-old woman who sustained a posterolateral elbow dislocation associated with a comminuted fracture of the radial head and coronoid—the “terrible triad.” C,D. Preoperative 3-D reconstruction images demonstrating a comminuted radial head fracture with a small undisplaced coronoid fracture. E,F. Postoperative radiographs after modular radial head arthroplasty (Evolve, Wright Medical Technology, Arlington, TN) and repair of the lateral collateral ligament. Medial collateral ligament and coronoid repairs were not required because the elbow was sufficiently stable at the end of the procedure. A good functional outcome was achieved at the final follow-up.

 

Preoperative Planning

 

Currently available devices include smooth stem spacer implants, press-fit ingrowth stems, monoblock and bipolar devices, and metallic or pyrolytic carbon articulations.

 

Most implants have an axisymmetric circular design; however, one currently available device has a more anatomic nonaxisymmetric elliptical shape.33,40,47

 

Silicone radial head implants offer little in the way of axial or valgus stability to the elbow and have been complicated by a high incidence of implant wear, fragmentation, and silicone synovitis leading to generalized

 

joint damage. As a result, they have fallen out of favor and have been replaced by metallic implants.18 Most metallic radial head implants that are currently available are modular with separate heads and stems,

allowing improved size matching of the native radial head and neck relative to older monoblock designs.17,28,30

 

Precise implant sizing and placement are critical with these devices to ensure correct capitellar tracking and to avoid a cam effect with forearm rotation, which may cause premature capitellar wear due to shearing of the

cartilage and stem loosening due to increased loading of the stem-bone interface.15

 

Preoperative radiographic templating of the contralateral normal radial head should be employed in the setting

of a secondary radial head replacement but is not needed for acute fractures because the excised radial head is available for accurate implant sizing.

 

Positioning

 

The patient is placed supine on the operating table and a sandbag is placed beneath the ipsilateral scapula to assist in positioning the arm across the chest.

 

Alternatively, the patient can be positioned in a lateral position with the affected arm held over a bolster or in the supine position with the arm on a hand table.5

 

 

Prophylactic intravenous antibiotics are administered. General or regional anesthesia is employed.

 

A sterile tourniquet is applied.

 

 

P.4023

 

 

 

TECHNIQUES

• Surgical Approach

  A midline posterior elbow incision is made just lateral to the tip of the olecranon (TECH FIG 1A).

  A full-thickness lateral fasciocutaneous flap is elevated on the deep fascia. This extensile incision decreases the risk of cutaneous nerve injury and provides access to the radial head, coronoid, and medial and lateral collateral ligaments for the management of more complex injuries (TECH FIG 1B).11,38

   

  TECH FIG 1 • A. The patient is placed supine on the operating table and a sandbag is placed beneath the ipsilateral scapula to assist in positioning the arm across the chest. The posterior incision is indicated in red. Alternatively, a lateral skin incision centered over the lateral epicondyle and passing obliquely over the radial head can be used (blue). B. A midline posterior elbow incision made just lateral to the tip of the olecranon. A full-thickness lateral fasciocutaneous flap is elevated on the deep fascia. This extensile incision allows access to both the lateral and medial aspects of the elbow, in case of more complex injuries, and reduces the incidence of cutaneous nerve injury.

   

  Alternatively, a lateral skin incision centered over the lateral epicondyle and passing obliquely over the radial head can be used (see TECH FIG 1A).

• Common Extensor Split

   

  The common extensor tendon is identified.

   

  The landmarks for this plane are a line joining the lateral epicondyle and the tubercle of Lister.

   

  The common extensor tendon is split longitudinally at the middle aspect of the radial head, and the underlying radial collateral and annular ligaments are incised (TECH FIG 2A).

   

  Dissection should stay anterior to the lateral ulnar collateral ligament to prevent the development of posterolateral rotatory instability (see FIG 1).

   

  The forearm is maintained in pronation to move the posterior interosseous nerve more distal and medial during the surgical approach.10

   

  If further exposure is required

   

  The humeral origin of the radial collateral ligament and the overlying extensor muscles are elevated anteriorly off the lateral epicondyle to improve the exposure if needed (TECH FIG 2B).

   

  Release of the posterior component of the lateral collateral ligament can be considered, but careful ligament repair is required at the end of the procedure in order to restore the varus and posterolateral rotatory stability of the elbow.13

   

   

   

  TECH FIG 2 • A. The common extensor tendon is split longitudinally at the middle aspect of the radial head, and the underlying radial collateral and annular ligaments are incised. The forearm is pronated to protect the posterior interosseous nerve. (continued)

   

   

  P.4024

   

   

   

  TECH FIG 2 • (continued) B. The humeral origin of the radial collateral ligament and the overlying extensor muscles are elevated anteriorly off the lateral epicondyle to improve the exposure if needed.

• Preparation of the Radial Head and Neck

   

  All fragments of the radial head are removed, as well as a minimal amount of radial neck at a right angle to the medullary canal, to make a smooth surface for seating of the prosthetic radial head.

   

  Complete fragment excision can be confirmed with the use of an image intensifier.

   

   

  The capitellum is evaluated for chondral injuries or osteochondral fractures. The radial head prosthesis is sized in one of several ways:

   

  The resected radial head is reassembled in the provided sizing template to assist in the accurate sizing of the prosthesis (TECH FIG 3A-C).

   

  The diameter of radial head prosthesis should be based on the minor diameter of the native radial head. This is typically 2 mm smaller than the major diameter of the elliptical native radial head.

   

   

   

  TECH FIG 3 • The resected radial head is reassembled in the provided sizing template (A) to assist in the accurate sizing of the prosthesis in terms of diameter (B) and height (C) and to ensure that all the fragments have been removed from the elbow. (continued)

   

   

  Alternatively, if the radial head has been previously excised, radiographic templating of the contralateral normal radial head may be used to determine the appropriate diameter and height of the radial head implant.

   

  If the native radial head is in between available implant sizes, the smaller implant diameter or thickness should be selected.

   

  The radial neck is delivered laterally using a Hohmann retractor carefully placed around the posterior aspect of the proximal radial neck (TECH FIG 3D).

   

  An anteriorly based retractor should be avoided because of the risk of injury from pressure on the posterior interosseous nerve.

   

  The medullary canal of the radial neck is reamed using hand reamers until cortical contact is encountered.

   

  A trial stem one size smaller than the rasp is inserted to achieve a loose press-fit.

   

   

  P.4025

   

   

   

  TECH FIG 3 • (continued) D. The radial neck is delivered laterally using a Hohmann retractor carefully placed around the posterior aspect of the proximal radial neck. An anteriorly based retractor should be avoided because of the risk of injury to the posterior interosseous nerve.

• Radial Head Replacement

   

  A trial head is inserted onto the stem, and the diameter, height, tracking, and congruency of the prosthesis are evaluated both visually and with the aid of an image intensifier.

   

  The radial head prosthesis should articulate at the same height as the radial notch of the ulna and about 1 to 2 mm distal to the tip of the coronoid (TECH FIG 4A).

   

  The alignment of the distal radioulnar joint and ulnar variance, as well as the width of the lateral and medial portions of the ulnohumeral joint, are checked and compared to the contralateral wrist and elbow, respectively, under fluoroscopy.

   

  Overlengthening the radiocapitellar joint with a radial head implant that is too thick should be avoided to reduce the risk of cartilage wear on the capitellum from excessive pressure; a nonparallel medial ulnohumeral joint space that is wider laterally is suggestive of overstuffing.4,16

   

   

   

  TECH FIG 4 • A. A trial stem is inserted. A trial head is inserted onto the stem and the diameter, height, tracking, and congruency of the prosthesis are evaluated both visually and with the aid of an image intensifier. B. Some modular and bipolar implants allow insertion of the stem first, then placement of the head onto the stem with coupling in situ, which significantly reduces the surgical exposure needed.

   

   

  Some modular and bipolar implants allow insertion of the stem first, then placement of the head onto the

  stem with coupling in situ, which significantly reduces the surgical exposure needed (TECH FIG 4B).

   

   

  If the prosthesis is maltracking on the capitellum with forearm rotation, a smaller stem size should be trialed to ensure that the articulation of the radial head with the capitellum is controlled by the annular ligament and articular congruency and not dictated by the proximal radial shaft.

   

• Lateral Soft Tissue Closure

  P.4026

   

  After radial head replacement, the lateral collateral ligament and extensor muscle origins are repaired back to the lateral condyle.

   

  If the posterior half of the lateral collateral ligament is still attached to the lateral epicondyle, then the anterior half of the lateral collateral ligament (the annular ligament and radial collateral ligament) and extensor muscles are repaired to the posterior half using interrupted absorbable sutures (TECH FIG 5A).

   

  If the lateral collateral ligament and extensor origin have been completely detached either by the injury or surgical exposure, they should be securely repaired to the lateral epicondyle using drill holes through bone and nonabsorbable sutures or suture anchors.

   

   

   

  TECH FIG 5 • A. If the posterior half of the lateral collateral ligament is still attached to the lateral epicondyle, then the anterior half of it (the annular ligament and radial collateral ligament) and extensor

  muscles are repaired to the posterior half using interrupted absorbable sutures. ECU, extensor carpi ulnaris; EDC, extensor digitorum communis. B-D. If the lateral collateral ligament and extensor origin have been completely disrupted by the injury or detached by the surgical exposure, they should be securely repaired to the lateral epicondyle. A single drill hole is placed at the center of the arc of curvature of the capitellum and connected to two drill holes placed anterior and posterior to the lateral supracondylar ridge. A locking (Krackow) suture technique is employed to gain a secure hold of the lateral collateral ligament

  (B) as well as of the annular ligament (C). (continued)

   

   

  A single drill hole is placed at the axis of motion (the center of the arc of curvature of the capitellum) and connected to two drill holes placed anterior and posterior to the lateral supracondylar ridge.

   

  A locking (Krackow) suture technique is employed to gain a secure hold of the lateral collateral ligament and common extensor muscle fascia (TECH FIG 5B-D).

   

  The ligament sutures are pulled into the holes drilled in the distal humerus using suture retrievers and the forearm is pronated, and varus forces are avoided, while tensioning the sutures before tying (TECH FIG 5E).

   

  The knots should be left anterior or posterior to the lateral supracondylar ridge to avoid prominence.

   

   

  P.4027

   

   

  TECH FIG 5 • (continued) D. A second stitch is used in a similar manner to repair the common extensor muscle fascia. E. The sutures are pulled into the holes drilled in the distal humerus using suture retrievers, tensioned while keeping the forearm pronated and while avoiding varus forces, and eventually tied over the lateral supracondylar ridge.

• Completion

   

  After replacement arthroplasty and lateral soft tissue closure, the elbow should be placed through an arc of flexion-extension while carefully evaluating for elbow stability in pronation, neutral, and supination.5

   

  Pronation is generally beneficial if the lateral ligaments are deficient,13 supination if the medial ligaments are deficient,2 and neutral position if both sides have been injured.

   

  In patients who have an associated elbow dislocation, additional repair of the medial collateral ligament and flexor-pronator origin should be performed if the elbow subluxates at 40 degrees or more of flexion.

   

  Tourniquet deflation and hemostasis should be secured before wound closure.

   

   

  P.4028

  Kocher Approach

   

  Alternatively, the radial head may be approached by using the Kocher interval32 between the extensor carpi ulnaris and anconeus.

   

  The fascial interval between these muscles is identified by noting the diverging direction of the muscle groups and small vascular perforators that exit at this interval (TECH FIG 6).

   

  Care should be taken to preserve the lateral ulnar collateral ligament, which is vulnerable as the dissection is carried deeper through the capsule.

   

   

   

  TECH FIG 6 • The extensor carpi ulnaris is elevated anteriorly, and an arthrotomy is performed at the midportion of the radial head. Care should be taken to preserve the lateral ulnar collateral ligament, which is vulnerable as the dissection is carried deeper through the capsule.

   

   

  PEARLS AND PITFALLS

   

  Indications

• Displaced unreconstructable fracture of the radial head with known or probable associated medial or lateral collateral or interosseous ligament injury

   

  Pearls ▪ A preoperative radiographic template of the contralateral native radial head should be used in the setting of a secondary radial head replacement.

  • Dissection should stay anterior to the lateral ulnar collateral ligament to prevent the development of posterolateral rotatory instability.

  • The radial head should be sized based on the minor diameter and thickness of the excised radial head.

  • The radial head implant is typically 2 mm smaller than the major diameter of the native elliptical radial head.

  • Radial head articular surface height should be at the level of the proximal radioulnar joint.

  • If the radial head does not track well on the capitellum, the stem should be downsized.

  • If the native radial head is in between implant sizes, the implant should, in general, be downsized.

  • Intraoperative fluoroscopy is used to assess the alignment of the radiocapitellar and distal radioulnar joints and to avoid overlengthening of the radius.

     

    Pitfalls ▪ Hohmann retractors should not be used around the anterior aspect of the radial neck, and the forearm should be kept pronated to avoid damage to the posterior interosseous nerve.

  • The surgeon should avoid overstuffing the thickness or diameter of the radial head because of the risk of capitellar wear and pain. Filling the gap between the capitellum and radial neck is not a useful landmark for prosthesis thickness because lateral soft tissues are often deficient owing to the surgical exposure or initial injury.

 

POSTOPERATIVE CARE

 

The elbow with stable ligaments should be splinted using anterior plaster slabs in extension and elevated for 24 to 48 hours to diminish swelling, decrease tension on the posterior wound, and minimize the tendency to develop a flexion contracture.

 

In the setting of a more tenuous ligamentous repair or the presence of some residual instability at the end of the operative procedure, the elbow should initially be splinted in 60 to 90 degrees of flexion in the optimal position of forearm rotation to maintain stability.

 

Perioperative antibiotics are continued for 24 hours postoperatively.

 

Indomethacin 25 mg three times daily for 3 weeks may be considered in patients undergoing radial head arthroplasty to decrease postoperative pain, reduce swelling, and potentially lower the incidence of heterotopic ossification.

 

Indomethacin should be avoided in elderly patients and those with a history of peptic ulcer disease, asthma, known allergy, or other contraindications to anti-inflammatory medications.

 

For an isolated radial head replacement treated with a lateral ulnar collateral ligament-sparing approach, active range of motion should be initiated on the day after surgery.

 

 

A collar and cuff with the elbow maintained at 90 degrees is employed for comfort between exercises.

 

P.4029

 

A static progressive extension splint is fabricated for nighttime use for patients without associated

ligamentous disruptions and is employed for a period of 12 weeks. The splint is adjusted weekly as extension improves.

 

In patients with associated elbow dislocations or residual instability, extension splinting is not implemented until 6 weeks after surgery.

 

Patients with associated fractures, dislocations, or ligamentous injuries should commence active flexion and extension motion within a safe arc 1 day postoperatively.

 

 

Active forearm rotation is performed with the elbow in flexion to minimize stress on the medial or lateral ligamentous injuries or repairs.

 

Extension is performed with the forearm in the appropriate rotational position—that is, pronation if the lateral

ligaments are deficient,13 supination if the medial ligaments are deficient,2 and neutral position if both sides have been injured.

 

A resting splint with the elbow maintained at 90 degrees and the forearm in the appropriate position of forearm rotation is employed for 3 to 6 weeks.

 

Passive stretching is not permitted for 6 weeks to reduce the incidence of heterotopic ossification.

 

Strengthening exercises are initiated once the ligament injuries and any associated fractures have adequately healed, usually at 8 weeks postoperatively.

 

 

OUTCOMES

Silicone radial head arthroplasty, although initially successful in many patients,8,42 has fallen out of favor because of problems with residual instability and arthritis, implant fracture, and silicone synovitis due to particulate debris.45

Although the short- and medium-term results of metallic radial head implants are encouraging, there is a paucity of literature demonstrating the long-term outcome with respect to loosening, capitellar wear, and arthritis.14,17

Metallic radial head replacement in elbows with intact ligaments restores the kinematics and stability similar to that measured with a native radial head. Moreover, when the fractured radial head occurs in combination with ligamentous and soft tissue disruption, a metallic prosthesis restores elbow stability, with only mild residual deficits in strength and motion.

Results appear to be better if surgery is performed early (<10 days from injury).3,34

Moro et al36 reported the functional outcome of 25 cases managed with a metallic radial head arthroplasty for unreconstructable fractures of the radial head at an average follow-up of 39 months. The results were rated as 17 good or excellent, 5 fair, and 3 poor.

The radial head prosthesis restored elbow stability when the fractured radial head occurred in combination with a dislocation of the elbow, rupture of the medial collateral ligament, fracture of the coronoid, or fracture of the proximal ulna.

There were mild residual deficits in strength and motion, and no patient required removal of the implant.

Grewal et al17 reported high satisfaction rate among 26 patients, 2 years following a modular, monopolar radial head arthroplasty with a loose press-fit stem for unreconstructable radial head fractures.

Zunkiewicz et al47 reported good functional outcome in 29 patients managed with a bipolar radial head prosthesis with a smooth unfixed telescoping stem with an average follow-up of 34 months. The prosthesis effectively restored stability and joint congruency to elbows with comminuted radial head fractures and valgus instability.

Flinkkilä et al15 reported high failure rate and early loosening of press-fit radial head implants which were used in acute unstable elbow injuries, 12 of 37 press-fit stems were radiographically loose at a mean follow-up of 11 months, with 9 of them necessitating implant removal.

Harrington et al20 reported their experience with metallic radial head arthroplasty in 20 patients at an average followup of 12 years. The results were excellent or good in 16 and fair or poor in 4.

Improvements in radial head arthroplasty designs, sizing, and implantation techniques may lead to improved outcomes for unreconstructable radial head fractures.

 

 

COMPLICATIONS

Posterior interosseous nerve injury can occur as a consequence of dissection distal to the radial tuberosity and placement of anterior retractors around the distal radial neck.

Infection

Loss of motion, mainly terminal extension due to capsular contracture, heterotopic ossification, or retained cartilaginous or osseous fragments

Prosthetic loosening, failure or polyethylene wear15,43 Capitellar wear and pain due to implant overstuffing Complex regional pain syndrome

Instability or recurrent dislocations of the elbow due to an inadequate or failed ligament repair

Osteoarthritis of the capitellum as a consequence of articular cartilage damage from the initial injury, from component insertion, from persistent instability, or due to loading from a radial head implant that is too thick

 

 

REFERENCES

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2. Armstrong AD, Dunning CE, Faber KJ, et al. Rehabilitation of the medial collateral ligament-deficient elbow: an in vitro biomechanical study. J Hand Surg Am 2000;25(6):1051-1057.

    

    

3. Ashwood N, Bain GI, Unni R. Management of Mason type-III radial head fractures with a titanium prosthesis, ligament repair, and early mobilization. J Bone Joint Surg Am 2004;86-A(2):274-280.

    

    

4. Athwal GS, Rouleau DM, MacDermid JC, et al. Contralateral elbow radiographs can reliably diagnose radial head implant overlengthening. J Bone Joint Surg Am 2011;93(14):1339-1346.

    

    

5. Bain GI, Ashwood N, Baird R, et al. Management of Mason type III radial head fractures with a titanium prosthesis, ligament repair, and early mobilization. J Bone Joint Surg Am 2005;87(suppl, 1 pt 1):136-147.

    

    

6. Beingessner DM, Dunning CE, Gordon KD, et al. The effect of radial head excision and arthroplasty on elbow kinematics and stability. J Bone Joint Surg Am 2004;86-A(8):1730-1739.

    

    

7. Boulas HJ, Morrey BF. Biomechanical evaluation of the elbow following radial head fracture. Comparison of open reduction and internal fixation versus excision, silastic replacement, and non-operative management. Chir Main 1998;17:314-320.

    

    

8. Carn RM, Medige J, Curtain D, et al. Silicone rubber replacement of the severely fractured radial head. Clin Orthop Relat Res 1986;(209):259-269.

    

    

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9. Davidson PA, Moseley JB Jr, Tullos HS. Radial head fracture. A potentially complex injury. Clin Orthop Relat Res 1993;(297):224-230.

    

    

10. Diliberti T, Botte MJ, Abrams RA. Anatomical considerations regarding the posterior interosseous nerve during posterolateral approaches to the proximal part of the radius. J Bone Joint Surg Am 2000;82(6):809-813.

     

     

11. Dowdy PA, Bain GI, King GJ, et al. The midline posterior elbow incision. An anatomical appraisal. J Bone Joint Surg Br 1995;77(5): 696-699

     

     

12. Duckworth AD, Clement ND, Jenkins PJ, et al. The epidemiology of radial head and neck fractures. J Hand Surg Am 2012;37(1):112-119.

     

     

13. Dunning CE, Zarzour ZD, Patterson SD, et al. Muscle forces and pronation stabilize the lateral ligament deficient elbow. Clin Orthop Relat Res 2001;(388):118-124.

     

     

14. El Sallakh S. Radial head replacement for radial head fractures. J Orthop Trauma 2013;27:e137-e140.

     

     

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