Bradford O. Parsons
DEFINITION
Simple elbow dislocation is a dislocation of the ulnohumeral joint without concomitant fracture.
Complex instability denotes the presence of a fracture associated with dislocation.
The elbow is the second most commonly dislocated large joint (excluding phalanx dislocations and so forth).
PATHOANATOMY
Elbow stability is conferred by both the osseous anatomy as well as the ligamentous anatomy.
Primary stabilizers of the ulnohumeral joint include the osseous architecture of the joint, including the coronoid process and greater sigmoid notch of the ulna, and the trochlea of the humerus.
The anterior band of the medial collateral ligament (aMCL) and the lateral ulnar collateral ligament (LUCL) are the primary ligamentous stabilizers of the elbow.9,12
The aMCL originates on the anterior inferior face of the medial epicondyle and inserts on the sublime tubercle of the ulna.
The LUCL originates from an isometric point on the lateral supracondylar column and traverses across the inferior aspect of the radial head, inserting on the supinator crest of the ulna.8
Secondary stabilizers include the radial head and dynamic constraints such as the flexor and extensor muscles of the forearm.
The anterior joint capsule is also felt to play a role in ulnohumeral stability.
O'Driscoll12 has proposed the term “posterolateral rotatory instability” (PLRI) to describe the series of pathologic events that result in ulnohumeral dislocation.
PLRI is felt to start with disruption of the LUCL and progresses medially with tearing of the anterior and posterior capsules. This allows the ulna to “perch” on the distal humerus. Further soft tissue or osseous injury results in dislocation13 (FIG 1A).
Most traumatic injuries to the LUCL result in avulsion of the ligament from the lateral humerus (FIG 1B).
As forces continue from lateral to medial across the joint, the anterior and posterior capsular tissues and eventually the MCL may be disrupted.
It is possible to dislocate the ulnohumeral joint with disruption of the LUCL and preservation of the aMCL.12
Common fractures that occur with elbow dislocation include radial head or neck and coronoid fractures, although any fracture about the elbow may be observed.
Radial head fractures are usually readily apparent on plain radiographs.
Coronoid fractures may be subtle, and even a “fleck” of coronoid is often a hallmark of a more significant injury (eg, “terrible triad” injury), and its importance should not be underestimated.
Recently, a variant of elbow instability termed postero medial rotatory instability (PMRI) has been described, which is a consequence of LUCL injury and medial coronoid facet fracture. This injury pattern is most commonly observed without radial head fracture, making it potentially very subtle on plain radiographs. A computed tomography (CT) scan can delineate this injury in detail and should be obtained if any suspicion exists (FIG 1C–E).2,11
ETIOLOGY AND CLASSIFICATION
Most elbow dislocations occur with a fall on an outstretched arm.
Forces of valgus, extension, supination, and axial load across the joint can result in the ulna rotating away from the humerus, disrupting lateral–anterior soft tissues initially, and dislocating the elbow.
Simple elbow dislocations are classified by the direction of displacement of the ulna in reference to the humerus, with posterolateral dislocation the most common.
Less common variants include anterior, medial, or lateral dislocations.
PATIENT HISTORY AND PHYSICAL FINDINGS
History is aimed at determining the timeline and mechanism of injury, frequency of dislocations, and previous treatment.
Unlike the shoulder, recurrent instability of the elbow is rare after an initial simple dislocation that was treated expediently.
Recurrent instability is more common in association with fractures (eg, the “terrible triad” injury).
Chronic instability, although rare in the United States, does occasionally occur, and management often requires reconstructive surgery or elbow replacement. Closed treatment is rarely successful in these patients.
Iatrogenic injury of the LUCL (during procedures such as open tennis elbow release or radial head fracture management) is a known cause of recurrent PLRI. However, these patients often complain of subtle lateral elbow pain due to subluxation of the joint with activities, such as rising from a chair, but rarely have recurrent dislocation.
Examination at the time of injury requires attention to the neurovascular anatomy.
Nerve injury can occur after elbow dislocation, and a thorough neurologic examination of the extremity is mandatory before any treatment of the dislocation.
Most nerve injuries are neuropraxia that often resolve.
The ulnar nerve is most frequently involved, although median or radial nerve injury may also occur.14
The dislocated elbow has obvious deformity, with the elbow often held in a varus position and the forearm supinated.
FIG 1 • A. Posterolateral rotatory instability follows a typical progression of disruption, allowing the joint to become perched and then dislocate as soft tissue injury progresses. B. Intraoperative photograph demonstrating avulsion of the origin of the lateral ulnar collateral ligament (LUCL) after traumatic dislocation of the elbow. The origin of the LUCL and the extensor muscles are avulsed as one layer, held by the forceps. C–E. Posteromedial rotatory instability is a variant of elbow instability in which the elbow dislocates, rupturing the LUCL, and the medial coronoid sustains an impaction fracture C,D. In this injury pattern, the radial head remains intact, making appropriate diagnosis of the severity of the injury difficult on standard radiographs. CT scans help better delineate the injury pattern. E. Impaction fracture can be seen on the 3D CT reconstruction. (A: Adapted from O'Driscoll SW, Morrey BF, Korinek S, et al. Elbow subluxation and dislocation: a spectrum of instability. Clin Orthop Relat Res 1982;280:194. C–E: Copyright the Mayo Foundation, Rochester, MN.)
After initial reduction, the neurovascular status of the limb is re-evaluated. Loss of neurologic function after closed reduction is rare but can be an indication for surgical exploration to rule out an entrapped nerve.
Stability of the joint is assessed based on the amount of extension obtainable and association of pronation or supination with instability (see the treatment algorithm section).
It is helpful to evaluate the stability throughout the elbow range of motion while the patient is still anesthetized, as this may guide treatment (examination under anesthesia).
Stressing of the lateral soft tissues is performed with the lateral pivot-shift maneuver, which can be performed under anesthesia and with fluoroscopic imaging12 (FIG 2).
This test can be used to assess the degree of posterolateral rotatory instability, and may aid in determining treatment.
Medial ecchymosis may be a sign of an aMCL injury, and often is apparent 3 to 5 days after dislocation when the MCL has been injured.
IMAGING AND OTHER DIAGNOSTIC STUDIES
Standard orthogonal radiographs of the elbow are obtained before and after reduction to assess for fracture and confirm relocation of the joint.
Congruency of the trochlea–ulna and radial head– capitellum is assessed.
Valgus stress views, once the joint is reduced, may help demonstrate an aMCL injury.
With the elbow flexed 30 degrees and the forearm in pronation, a valgus stress is placed under fluoroscopic evaluation to see if the medial ulnohumeral joint opens compared to the resting state.
Varus stress views are often not helpful.
CT scans with 3D reconstructions are obtained in any situation where a fracture may be suspected, as it is critical to identify PMRI variants or subtle coronoid fractures, which may be an indication for surgical management.
Magnetic resonance imaging (MRI) is usually not necessary in the management of simple dislocation, although if questions regarding the integrity of the MCL exist, an MRI can delineate this structure well.
NONOPERATIVE MANAGEMENT
Most simple dislocations may be managed nonoperatively with splinting or bracing, guided by the degree of instability determined during the examination under anesthesia after reduction.12
Once reduced, elbow stability is assessed during flexion– extension in neutral forearm rotation.
If the elbow is stable throughout an arc of motion, it is immobilized in a sling or splint for 3 to 5 days for comfort and then range-of-motion exercises are begun.
FIG 2 • A. The lateral pivot-shift maneuver is performed with the patient's arm positioned overhead, and a supination–valgus stress is applied. As the elbow is brought into flexion the joint reduces, often with a clunk. B. When performed under fluoroscopy, subluxation of the radial head posterior to the capitellum can be observed, consistent with posterolateral rotatory instability. (B: From O'Driscoll SW, Bell DF, Morrey BF. Posterolateral rotatory instability of the elbow. J Bone Joint Surg Am 1991;73A:440–446.)
If instability is present in less than 30 degrees of flexion, the forearm is pronated and stability is reassessed.
If pronation confers stability, then a hinged orthosis that maintains forearm pronation is used, after 3 to 5 days of splinting, to allow protected range of motion.
Elbows that sublux (confirmed by fluoroscopic imaging) in less than 30 degrees of flexion and pronation of the forearm are managed with a brief period of splinting, followed by a hinged orthosis that controls rotation of the forearm and has an extension block.
Elbows that are unstable in more than 30 degrees of flexion and pronation often are managed surgically.
Hinged bracing is maintained for 6 weeks, with progressive advancement of extension and rotation, as allowed by stability of the joint.
Weekly radiographs are needed to ensure maintenance of a congruent joint during the first 4 to 6 weeks.
After 6 weeks bracing is discontinued and terminal stretching to regain motion is used if flexion contractures exist.
SURGICAL MANAGEMENT
Indications
Surgical management is indicated in elbows that are unstable, even when placed in flexion (more than 30 degrees) and pronation, elbows that recurrently sublux or dislocate during the treatment protocol, or those with associated fractures (“complex” instability).
Management of simple dislocation requires repair or reconstruction of those ligamentous injuries resulting in instability. By definition, simple dislocation occurs without fracture.
An algorithmic approach to ligament repair is used to stabilize the elbow. The LUCL is felt to be the primary lesion of dislocation, and therefore this ligament is addressed first, followed by assessment of stability.
The LUCL usually avulses from its origin during dislocation, and therefore most often can be repaired after acute injury.
Repair may be performed via bone tunnels in the humerus or with suture anchors, depending on the surgeon's preference.
Reconstruction of the LUCL is rarely needed in acute management but is more commonly needed in chronic instability.
Reconstruction, when necessary, uses autograft (either palmaris or gracilis) or allograft.
Often, repair or reconstruction of the LUCL confers stability, even in the face of MCL injury, as the intact radial head is a secondary stabilizer to valgus instability.
Persistent instability after LUCL repair is rare and is more commonly observed with fracture-dislocations or chronic instability.
If persistent instability exists, the MCL is repaired or reconstructed, a hinged external fixator is placed, or both are performed.
This section will discuss the surgical technique of LUCL repair and reconstruction.
Preoperative Planning
Planning should include the possibility of reconstruction of the LUCL using autograft, which will be harvested at surgery, or by having allograft available.
If autograft is to be harvested, a tendon stripper is needed.
For allograft we routinely use semitendinosus tendon.
A hinged external fixator should be available in the rare case that the elbow remains unstable after ligamentous repair or reconstruction.
2.0and 3.2-mm drill bits or burrs are used to make bone tunnels for LUCL repair or reconstruction.
Alternatively, some surgeons prefer suture anchor repair of ligament avulsions; if desired, these should be available.
Fluoroscopy is useful for confirming reduction and is required for placement of a hinged external fixator.
A sterile tourniquet is used if exposure of the proximal humerus is necessary for placement of proximal external fixator pins.
Patient Positioning
Patients are positioned supine with the arm on a radiolucent hand table.
A small bump is placed under the scapula to aid in arm positioning.
The forequarter is draped free to ensure the entire brachium is kept in the surgical field.
If hamstring autograft is to be used for LUCL, the leg should be draped free and a bump is placed under the hemipelvis to aid in exposure.
TECHNIQUES
LATERAL ULNAR COLLATERAL LIGAMENT REPAIR
Surgical Approach and Arthrotomy
The radiocapitellar joint and coronoid are inspected to confirm no fractures are present and that no soft tissue is interposed in the joint, preventing reduction.
Once the joint is clear of debris, the ability to obtain a concentric reduction is confirmed with fluoroscopy.
Tourniquet control is used during this procedure.
Two different surgical approaches are used to manage elbow instability.
Often, a posterior midline skin incision can be used to gain access to both the medial and lateral aspects of the joint; therefore, it is a very extensile approach to the elbow.
Alternatively, a “column” incision, centered over the lateral epicondyle, may be used (TECH FIG 1A). If medialsided exposure is needed, a similar “column” incision may be made over the medial epicondyle to gain access.
There are benefits to both approaches, and currently no data exist delineating which approach is better.
For simple dislocation we routinely use a lateral column approach.
After skin incision, skin flaps are raised anteroposterior at the level of the deep fascia.
Often the lateral soft tissues are avulsed off the epicondyle, exposing the joint. Occasionally, however, the extensor origin is intact with an underlying ligament injury.
If the extensor muscles are intact, the interval between the extensor carpi ulnaris (ECU) and anconeus (the Köcher approach), which directly overlies the LUCL, is used. This interval is often readily identified by the presence of a “fat stripe” in the deep fascia (TECH FIG 1B).
The elbow joint is then exposed by incising the proximal capsule along the lateral column of the humerus, continuing distally along the radial neck (through the supinator muscle and underling capsule) in line with the ECU–anconeus interval.
The posterior interosseous nerve (PIN) is at risk with this exposure, and therefore the forearm is kept in pronation to protect the PIN.
Ligament Repair
The origin of the LUCL is identified.
Often, the LUCL is avulsed from the isometric point on the lateral capitellum, and the origin can be identified by a “fold” of tissue on the deep surface of the capsule (TECH FIG 2A).
Starting at the origin, a running no. 2 nonabsorbable Krackow locking suture is placed along the anterior and posterior aspect of the ligament. Once placed, the suture–ligament construct is tensioned to confirm the integrity of the insertion onto the ulna.
A common mistake is to start the repair at the level of the proximal origin of the superficial tissue, which is not the origin of the LUCL but part of the extensor origin.
The isometric origin on the humerus is then identified in the center of the capitellum, not the lateral epicondyle (TECH FIG 2B,C).
Confirmation of the isometric point is made by clamping the limbs of the running suture at the point of isometry and then flexing and extending the elbow to confirm proper placement.
A 2.0-mm burr is used to make a humeral bone tunnel.
It is critical to make the most anterior aspect of the bone tunnel at the isometric point, not the center of the tunnel, as this small translation can result in a lax LUCL repair (TECH FIG 2D).
Two “exit” tunnels (in a Y configuration), one anterior and one posterior to the lateral column, are then made with a 2.0-mm drill bit or burr, connected to the distal humeral tunnel at the isometric point.
TECH FIG 1 • A. Lateral column skin incision. The lateral incision is centered over the epicondyle and radiocapitellar joint and is often the primary incision, as the lateral ulnar collateral ligament (LUCL) rupture is thought to be the primary injury in simple dislocations. B. The deep interval between the extensor carpi ulnaris and anconeus is used to gain exposure to the joint. This is often identified by a “fat stripe” in the fascia. Care should be taken not to violate the LUCL, which traverses in line with this interval deep to the fascia and supinator muscle.
TECH FIG 2 • A. The origin of the lateral ulnar collateral ligament (LUCL), which often avulses during elbow dislocation, is identified by a “fold” of tissue on the deep surface of the capsule. The isometric point of the joint is in the center of rotation of the capitellum (B), and confirmation is made using the previously placed sutures in the ligament remnant to ensure that an isometric repair will be obtained (C). D. It is important to make the humeral tunnel so that the most anterior aspect of the tunnel is placed at the isometric point. Exit holes for the humeral tunnel are made anterior and posterior to the lateral supracondylar ridge (B).
Once the humeral tunnels are completed, the limbs of the running suture are passed through the humeral tunnels.
The joint is concentrically reduced with fluoroscopic confirmation and the LUCL repair sutures are then tied with the joint reduced and the elbow in 30 degrees of flexion and neutral rotation.
The elbow is ranged through an arc of motion to assess stability, with careful attention placed on the radial head's articulation with the capitellum, looking for posterior sag in extension, indicating either a lax LUCL or a nonisometric repair.
If the elbow is stable through an arc of motion, the extensor origin is repaired with interrupted, heavy (no. 0) nonabsorbable suture and the skin is closed in layers.
LATERAL ULNAR COLLATERAL LIGAMENT RECONSTRUCTION
Occasionally, the native LUCL is damaged beyond repair (more often with iatrogenic PLRI than with primary instability) or attenuated after recurrent or chronic elbow instability, and reconstruction is necessary.
Autograft palmaris or gracilis or allograft may be used.
Autograft and allograft options should be discussed with the patient and decisions made preoperatively. We routinely use semitendinosus allograft unless the patient desires autograft.
This section will cover the technique of ligament graft reconstruction once tendon graft has been harvested.
Bone Tunnel Preparation
We use a “docking” technique, similar to those described for MCL reconstruction,1 for LUCL reconstruction.
The insertion of the LUCL is at the supinator crest of the ulna, and reconstruction begins with creation of the ulnar tunnels at the supinator crest.
Reflecting the supinator origin from the ulna posterior to the radial head exposes the supinator crest.
The forearm is held in pronation to protect the PIN.
Once the crest is exposed, the ulnar tunnel is made at the level of the radial head using two 3.4-mm burr holes placed 1 cm apart. Care is taken to connect the holes using small curettes or awls without fracturing the roof of the tunnel (TECH FIG 3).
Once the ulnar tunnel is made, a suture is placed in the tunnel to aid in graft passage and to help identify the isometric point on the humerus, similar to the technique described with ligament repair.
Once the isometric origin on the humerus is confirmed, humeral bone tunnels are made as mentioned in the LUCL repair section.
With LUCL reconstruction the isometric tunnel is deepened to about 1 cm to allow graft docking.
Further, the docking tunnel is widened using a 3.4mm burr to be able to accept both limbs of the graft.
It is important to widen the docking hole anterior and proximal to the isometric point, as the most posterior aspect of the tunnel needs to be at the isometric point.
Graft Preparation
One end of the graft is freshened and tubularized using a no. 2 nonabsorbable suture in a running Krackow fashion.
The graft is then passed through the ulnar bone tunnels using the passage suture previously placed.
The limb of the graft with locking suture is then fully docked into the humeral origin, and the joint is reduced.
The final length of the graft is determined by tensioning the graft and identifying the point at which the free limb of the graft meets the isometric origin. This point is marked on the graft.
Care should be taken to ensure appropriate graft tension and length by fully docking the first limb and then marking the free limb at the point of initial contact with the humerus, thereby allowing some overlap of graft limbs in the humeral tunnel but minimizing the likelihood of slack in the final construct.
The marked graft end is then freshened and tubularized in an identical fashion as the other limb.
Final Reconstruction
Once the graft is placed and ready for final tensioning and fixation, the capsule and remnant of the LUCL is repaired back to the humerus in an effort to make the ligament reconstruction extra-articular, if possible.
Each limb of the graft is then placed into the isometric docking tunnel on the humerus with corresponding limbs from each locking suture exiting the proximal humeral tunnels.
Both limbs of locking suture from one end of the graft are passed through one proximal tunnel in the humerus, followed by the limbs from the other end of the graft through the second proximal tunnel.
The joint is then reduced and the graft is finally tensioned to ensure there is no slack and neither graft end has “bottomed out” in the humeral docking tunnel.
The locking sutures are then tied together over the lateral column of the distal humerus with the joint concentrically reduced in 30 degrees of flexion and neutral rotation.
The joint is then ranged and stability assessed. If the joint is stable, no further reconstruction is necessary and the extensor muscles are repaired using a nonabsorbable interrupted stitch, followed by skin closure.
TECH FIG 3 • The insertion of the lateral ulnar collateral ligament is the supinator crest of the ulna. Reconstruction uses an ulnar tunnel in the supinator crest made at the level of the radial head. Holes are made about 1 cm apart and connected to form a tunnel.
HINGED EXTERNAL FIXATION
A hinged fixator may be necessary in chronic dislocations, some fracture-dislocations, or rarely in patients with persistent instability after LUCL repair or reconstruction for simple dislocation.4,16
Once any soft tissue blocking reduction is removed and a concentric reduction can be obtained, the fixator is placed.
All hinged elbow fixators are constructed around the axis or rotation of the elbow to allow range of motion to occur while maintaining a concentric reduction.
Most implants are built around an axis pin, placed in this center of rotation.
The center of rotation is identified as the center of the capitellum on a lateral aspect of the elbow, and on the medial side it is just anteroinferior to the medial epicondyle, in the center of curvature of the trochlea (TECH FIG 4).
The axis pin is placed through both of these points, parallel to the joint surface, and the position is confirmed by fluoroscopy.
After placement of the axis pin, the humeral and ulnar pins are placed after confirmation of concentric reduction of the elbow is made.
Once the external fixator is fully constructed, the elbow is taken through an arc of motion and maintenance of reduction is confirmed.
Fixators are kept on for 6 to 8 weeks.
Meticulous pin care is necessary to minimize pin tract infections or loosening.
TECH FIG 4 • The center of rotation of the elbow, along which an axis pin for hinged fixators is placed, is identified by the center of the capitellum and just anteroinferior to the medial epicondyle.
PEARLS AND PITFALLS
POSTOPERATIVE CARE
After operative stabilization without external fixation, the elbow is splinted in flexion for 3 to 5 days to allow wound healing.
Range-of-motion exercises are then begun in flexion, extension, and rotation, with care taken to avoid varus or valgus stress.
A hinged orthosis can be helpful in protecting the ligament repair or reconstruction.
Active and passive motion is continued for 6 weeks, when strengthening is added.
Residual contractures, often loss of extension, can be managed with static splinting and terminal stretching.
OUTCOMES
Most series have reported the results of closed management of simple dislocation.
Mehlhoff and colleagues7 reported the results of 52 simple dislocations managed, with most patients having normal elbows. Length of immobilization, especially greater then 3 weeks, was found to be more likely to result in persistent loss of extension.
Similarly, Eygendaal and colleagues3 reported the longterm results of 50 patients after closed management of simple dislocations. Sixty-two percent of patients described their elbow function as good or excellent, and 24 of 50 (48%) patients had loss of extension of 5 to 10 degrees.
Some series have examined the surgical management of PLRI, often as a result of recurrent instability after traumatic dislocation.
Nestor and colleagues10 reported the results of 11 patients with recurrent PLRI managed with either repair or reconstruction of the LUCL. Ten of 11 (91%) remained stable and 7 of 11 (64%) had an excellent result.
More recently, Sanchez-Sotelo and colleagues15 reported the results of 44 patients treated for recurrent PLRI (9 occurred after simple dislocation). Thirty-two (75%) of the patients had an excellent result by Mayo score.
Lee and Teo5 found that in patients with chronic PLRI, reconstruction offered more predictable outcomes over repair.
COMPLICATIONS
Stiffness3,7
Heterotopic ossification6
Neurovascular injury14
Recurrent instability3,7
Compartment syndrome
Hematoma or infection
REFERENCES
1. Dodson CC, Thomas A, Dines JS, et al. Medial ulnar collateral ligament reconstruction of the elbow in throwing athletes. Am J Sports Med 2006;34:1926–1932.
2. Doornberg JN, Ring DC. Fracture of the anteromedial facet of the coronoid process. J Bone Joint Surg Am 2006;88A:2216–2224.
3. Eygendaal D, Verdegaal SH, Obermann WR, et al. Posterolateral dislocation of the elbow joint: relationship to medial instability. J Bone Joint Surg Am 2000;82A:555–560.
4. Jupiter JB, Ring D. Treatment of unreduced elbow dislocations with hinged external fixation. J Bone Joint Surg Am 2002;84A: 1630–1635.
5. Lee BP, Teo LH. Surgical reconstruction for posterolateral rotatory instability of the elbow. J Shoulder Elbow Surg 2003;12:476–479.
6. Linscheid RL, Wheeler DK. Elbow dislocations. JAMA 1965;194: 1171–1176.
7. Mehlhoff TL, Noble PC, Bennett JB, et al. Simple dislocation of the elbow in the adult. Results after closed treatment. J Bone Joint Surg Am 1988;70A:244–249.
8. Morrey BF, An KN. Functional anatomy of the ligaments of the elbow. Clin Orthop Relat Res 1985;201:84–90.
9. Morrey BF, Tanaka S, An KN. Valgus stability of the elbow: a definition of primary and secondary constraints. Clin Orthop Relat Res 1991;265:187–195.
10. Nestor BJ, O'Driscoll SW, Morrey BF. Ligamentous reconstruction for posterolateral rotatory instability of the elbow. J Bone Joint Surg Am 1992;74A:1235–1241.
11. O'Driscoll SW. Acute, recurrent, and chronic elbow instabilities. In: Norris TR, ed. Orthopaedic Knowledge Update: Shoulder and Elbow 2. Rosemont, IL: American Academy of Orthopaedic Surgeons, 2002:313–323.
12. O'Driscoll SW, Bell DF, Morrey BF. Posterolateral rotatory instability of the elbow. J Bone Joint Surg Am 1991;73A:440–446.
13. O'Driscoll SW, Morrey BF, Korinek S, et al. Elbow subluxation and dislocation: a spectrum of instability. Clin Orthop Relat Res 1992;280:186–197.
14. Rana NA, Kenwright J, Taylor RG, et al. Complete lesion of the median nerve associated with dislocation of the elbow joint. Acta Orthop Scand 1974;45:365–369.
15. Sanchez-Sotelo J, Morrey BF, O'Driscoll SW. Ligamentous repair and reconstruction for posterolateral rotatory instability of the elbow. J Bone Joint Surg Br 2005;87B:54–61.
16. Tan V, Daluiski A, Capo J, et al. Hinged elbow external fixators: indications and uses. J Am Acad Orthop Surg 2005;13:503–514.