Shoulder and Elbow

Evaluation and Management of Complex Elbow Dislocations

The Problem

Complex elbow dislocations are characterized by instability of the elbow with associated fractures. These are difficult injuries to treat with relatively poor outcomes when compared to simple elbow dislocations. The extent of injury can vary greatly from minor fractures to severe injuries with multiple fractures and soft tissue damage. The term "terrible triad" has been used to describe an elbow dislocation with associated coronoid and radial head fractures because of the high rates of stiffness or instability following this injury pattern.

Clinical Presentation

Mechanism of Injury

Complex elbow dislocations present following acute trauma; which is typically a fall on to an outstretched arm. In younger patients it is often the result of high energy injuries such as a fall from height or motor vehicle accidents. In the elderly population with poor bone quality, patients can present with lower energy injuries including a fall from standing height.

Presentation

Patients present with pain and elbow deformity, and there may be associated neurologic or vascular injuries to the extremity. Depending on the mechanism of injury there may be injuries to other extremities or organ systems, and a full trauma evaluation may be indicated.

Diagnostic Workup

Classic physical exam findings:

  • A comprehensive examination of musculoskeletal system and possibly a full trauma evaluation is required depending on the mechanism of injury.

Pre-reduction elbow examination:

  • Pain, swelling and deformity of the elbow.

  • Crepitation and instability with range of motion.

  • Neurologic examination: motor and sensory evaluation of the median, radial and ulnar nerves. Serial examinations may be required in cases of significant swelling or soft tissue injury to monitor for compartment syndrome.

Post-reduction:

  • Range of motion - evaluate for blockage to motion or instability with elbow extension, assess differences in stability with forearm supination and pronation.

  • Repeat neurologic examination

  • Ligamentous stability: Varus and Valgus stress testing at 0, 30 and 60 degrees of elbow flexion

    • Special Tests:

      • Pivot Shift

      • Posterolateral rotatory drawer test

Imaging findings

Radiographs: AP, Lateral, Radial Head (Figure 1, Figure 2)

Figure 1.

Posterior elbow dislocation with coronoid fracture.

Figure 2.

Posterior elbow dislocation with coronoid fracture.

  • Assessment of joint alignment and fractures is important. Pre-reduction x-rays are helpful in assessing the extent of the traumatic injury. Post-reduction radiographs are essential to ensure joint reduction and to determine the associated fractures and joint stability. Careful assessment for joint incongruity or incarcerated fracture fragments is important to prevent damage to the articular cartilage.

CT Scans:

  • Post-Reduction scan with 3-D reconstruction is a valuable tool in determining the extent of the bone injury and planning for surgical fixation.

    • Coronoid: the size and location of the coronoid fracture can affect the surgical decision making process. Classification systems include the Regan and Morrey and the O'Driscoll classificatons.

    • Figure 3.

    3-D CT scan of elbow dislocation following reduction showing type II coronoid fracture.

    • Radial Head: The size, number and displacement of the fracture fragments all influence the decision between non-operative management, surgical fixation or replacement. The Mason classification is the most commonly used system for radial head fractures.

    • Capitellum/Trochlea: Fractures of the distal humeral articular surface typically require surgical fixation.

    • Epicondyles: Indicates a bony avulsion of the forearm musculature and/or the collateral ligaments, displacement >1 cm or significant instability are indications for surgical fixation.

MRI scan:

  • Can provide additional information regarding ligamentous injuries to the collateral ligaments or associated cartilage injury. MRI scans are not routinely ordered but may help in the surgical decision making process if the fractures are non-displaced or do not significantly altar the stability of the elbow.

Special diagnostic tests

EMG/NCS:

  • Are indicated in cases of motor or sensory deficit that does not resolve by 4 weeks.

Non–Operative Management

Closed Reduction and Splinting:

  • Initial management in the acute setting is to perform closed reduction.

  • Sedation is not essential but is helpful for obtaining an atraumatic reduction and for evaluation of elbow stability following reduction.

  • Reduction maneuvers can vary based on the direction of the dislocation and the associated fracture pattern.

  • Splinting may be required depending on the stability of the elbow after reduction.

    • An elbow that is stable through a full range of motion can be placed in a sling.

    • An unstable elbow needs to be splinted. The position of the arm may vary based on the type of fracture or instability pattern.

Definitive non-operative management:

  • Most complex elbow dislocations will require surgical treatment. However, non-operative management is appropriate for patients with non-displaced fractures or fractures that do not compromise the bony stability of the elbow.

  • Repeat evaluation of the elbow stability is performed within 7-10 days following injury. If the elbow is stable a program of gravity and active assisted elbow flexion and extension is begun. Patients are given a removable posterior splint or elbow range of motion brace locked at 90 degrees that is to be worn at all times except when performing elbow range of motion exercises.

  • Non-weight bearing is continued until 6 weeks following injury at which time use of the elbow is permitted in a range of motion brace with lifting restriction of 1lb. Active range of motion exercises and forearm strengthening exercises are initiated.

  • Lifting restrictions are kept until 3 months or until fractures are healed and elbow is stable on clinical examination.

Indications for Surgery

Surgical intervention is required in most complex elbow dislocations. The indications for surgery include recurrent elbow instability, joint incongruity, fractures that compromise the bony stability or displaced intraarticular fractures.

  • Coronoid fractures (Figure 4, Figure 5)

  • Radial Head fractures (Figure 6)

  • Intraarticular fractures (Figure 7)

Figure 4.

Coronoid tip fracture.

Figure 5.

Anteromedial coronoid fracture.

Figure 6.

Valgus impacted radial head fracture after elbow dislocation.

Figure 7.

Elbow dislocation with associated olecranon and radial head fractures.

Surgical Technique

Necessary equipment/instrumentation

The Instrumentation needed will depend on the constellation of fractures and soft tissue injuries that need to be addressed.

  • Coronoid: plating systems, 2.5 mm screws or sutures.

  • Radial Head: plating systems, 2.5 mm screws, headless compression screws or a radial head prosthesis.

  • Articular fractures: olecranon or distal humeral plating system, headless screws, absorbable sutures.

  • External Fixator: Hinged or rigid depending on surgeon preference.

Patient Set–Up

The position of the patient may vary depending on the surgical treatment plan. The most common position is supine with the arm on a radiolucent hand table or with the arm over the chest. The arm is prepped from the fingers to the axilla and a sterile tourniquet is used during the procedure. The use of fluoroscopy is needed during the procedure and ensuring access for imaging is essential in the room setup.

Step–by–step description of procedure

The surgical treatment will depend on the fractures and associated soft tissue injuries.

1. Examination under anesthesia: assessment of the stability and range of motion of the elbow is helpful in determining what structures will need to be repaired.

2. Exposure: Surgical approaches will depend on the fractures being addressed.

  • Lateral: A lateral column approach is used for radial head, capitellum and coronoid tip fractures. The incision is made along the lateral column starting 3 cm above the epicondyle and extending distally for 4 cm. The fascial incision is made along the supracondylar ridge proximally and extends distally into the common extensior tendon between the extensor carpi radialis and the extensor digitorum. The underlying lateral ligament complex will be torn, most commonly from the origin on the epicondyle. This will allow for exposure of the radial head, capitellum, as well as the tip of the coronoid.

  • Medial: Type II and III coronoid fractures and anteromedial facet fractures will often need to be addressed using a medial approach. The medial approach begins with an incision over the medial column. The ulnar nerve is identified in the cubital tunnel and an anterior subcutaneous transposition is performed. The flexor carpi ulnaris is elevated off the ulna distally to proximally to expose the base of the coronoid and the medial collateral ligament. If needed the flexor pronator muscle group can be released at the level of the medial epicondyle to improve exposure.

  • Posterior: Olecranon or proximal ulna fractures utilize a posterior approach over the subcutaneous border of the ulna. If both medial and lateral approaches are planned a single posterior skin incision can be used with subcutaneous dissection to the desired deep intervals. In cases of a displaced olecranon fracture the coronoid and radial head fractures can be exposed by working through the fracture site.

3. Fracture Fixation:

  • Radial Head:

    • Open reduction and internal fixation of a radial head fracture with less than three parts can be performed with traditional 2.5 mm screws or headless compression screws. A plate may be needed if there is a displaced fracture of the radial neck.

    • Figure 8.

    Screw fixation of radial head fracture after dislocation.

    • Radial head replacement is indicated when there is comminution (> 3 pieces) or significant damage to the articular surface. There are many available radial head plating systems and replacements available and the surgeon should choose one that he or she is comfortable with.

  • Cornoid:

    • Fixation of coronoid tip fractures is controversial. Larger tip fragments should be fixed with a screw or threaded pin from the posterior aspect of the proximal ulna. Smaller fragments that cannot be fixed with a screw can be fixed with a suture technique or excised depending on the stability of the elbow. (Figure 9, Figure 10)

    • Type II and III coronoid fractures or fractures of the anterior medial facet require fixation with screws or a buttress plate, and may require a separate medial approach. There are several pre-contoured plates on the market or a mini-fragment plate can be contoured to act as a buttress plate. (Figure 11, Figure 12)

Figure 9.

Fixation of coronoid fracture with threaded pin and repair of LUCL.

Figure 10.

Fixation of coronoid fracture and repair of LUCL.

Figure 11.

Figure 12.

Lateral radiograph following fixation of anteromedial coronoid fracture and repair of LUCL injury.

  • Capitellum:

    • Fractures of the capitellum are fixed using headless compression screws from anterior to posterior or traditional lag screws from posterior to anterior. Smaller fragments can be fixed with an absorbable suture passed around the fragment and tied over the posterior cortex.

  • Olecranon:

    • A simple fracture without comminution can be fixed with either a tension band or plate and screw construct. In cases of comminution or associated coronoid fractures, fixation with a plate and screws is needed. Care should be taken in comminuted fractures to avoid decreasing the radius of curvature of the greater sigmoid notch. (Figure 13, Figure 14)

Figure 13.

Fixation of olecranon fracture and replacement of radial head.

Figure 14.

Fixation of olecranon fracture and replacement of radial head.

4. Ligament Repair or Reconstruction:

  • Lateral ulnar collateral ligament:

    • Most common injury is an avulsion from the epicondyle; but distal avulsions or small fractures of the insertion of the supinator crest have been described.

    • Primary repair is possible in most cases using drill holes through the lateral epicondyle or with a suture anchor. Anatomic repair is essential to re-establish isometric tension on the ligament.

    • In cases of chronic instability or insufficient ligament for primary repair a reconstruction is performed with autograft palmaris longus graft or allograft.

    • Repair of ligament is performed in 90 degrees of flexion and pronation if the medial collateral ligament is intact. In cases of associated medial collateral ligament injury the forearm is kept supinated to prevent over-tensioning of the ligament.

  • Annular ligament:

    • Can be damaged in cases of radial head or coronoid fractures. If not injured it may need to be incised to allow for exposure as part of the lateral approach.

    • Repair with absorbable sutures can be performed but is not essential if the proximal radioulnar joint is stable.

  • Medial collateral ligament:

    • Repair is rarely needed if the fractures are fixed anatomically and the lateral ligament complex is repaired.

    • In rare cases of persistent instability after repair of all other structures primary repair through bone tunnels in the medial epicondyle or with a suture anchor can be performed using a medial approach. (Figure 15, Figure 16)

Figure 15.

MCL rupture with persistent Valgus instability following screw fixation of radial head fracture.

Figure 16.

Restoration of stability following repair of MCL with suture anchor.

  • Anterior capsule:

    • Although not a true ligament an anterior capsule tear associated with a small or irreparable coronoid fracture should be repaired using sutures passed through bone tunnels in the coronoid and tied over the posterior cortex of the ulna.

5. External Fixator placement:

  • In cases of persistent instability despite fixation of fractures and repair of ligaments the placement of an external fixator will hold a concentric reduction while the capsule and ligaments heal. External fixators can be hinged to allow for elbow range of motion or static. The author's preference is for a hinged external fixator which is locked at 90 degrees for 1 week followed by active and passive range of motion in the fixator for an additional 5 weeks. After 6 weeks the fixator is removed and the elbow is gently manipulated. (Figure 17, Figure 18)

Figure 17.

External fixation of elbow with instability following fixation of coronoid and ligament repair.

Figure 18.

External fixation of elbow with instability after fixation of coronoid and ligament repair.

Pearls and Pitfalls of Technique

Pearls

1. Examination of the elbow under anesthesia following initial reduction is helpful in assessing the stability of the elbow and the need for surgery.

2. CT scan of the elbow following reduction with 3-D reconstruction is of great value in determining the constellation of fractures and for surgical planning.

3. Rigid fixation of fractures and repair or reconstruction of the soft tissue injures to recreate stability of the elbow is essential prior to leaving the operating room. In cases where stability is not obtained an external fixator is needed.

Pitfalls

1. Failure to recognize displaced coronoid or radial head fractures on post reduction x-rays can often result in failure of non-operative treatment of elbow dislocations.

2. Failure to obtain rigid fixation or a stable elbow during surgery will result in fracture non-union, malunion and/or recurrent instability.

3. Failure to initiate early range of motion will result in elbow stiffness and contractures.

Potential Complications

Recurrent Instability:

  • Fracture non-union, malunion or failure of a ligament repair can result in recurrent dislocation. Assessment of the etiology for the repeat dislocation is essential for revision surgery.

Contracture/loss of motion:

  • The loss of motion is expected following these injuries. Patients should be counseled prior to surgery that the goal is to obtain functional range of motion.

  • Individuals that fail to gain functional range of motion are eligible for contracture release.

Heterotopic ossification/synostosis: (Figure 19)

Figure 19.

Heterotopic ossification of medial and lateral collateral ligaments following dislocation.

  • Limited heterotopic ossification that does not affect range of motion or stability is common following complex dislocations. Clinically significant heterotopic bone or a radioulnar synostosis is much less common. Excision of heterotopic bone is indicated after maturation, which typically occurs after 3 to 6 months.

  • The efficacy of indomethacin or radiation to prevent heterotopic bone formation in complex dislocations has not been proven. Consideration of prophylaxis should be performed in patients with associated head trauma or prolonged ICU admission or intubation.

Nerve Injury:

  • The radial nerve and posterior interosseous nerve are at risk during the lateral approach.

  • The ulnar and median nerves are at risk during medial approaches.

Post-Traumatic arthritis:

  • Fracture non-unions or malunions and hardware penetration into the articular surfaces can contribute to the cartilage injury that occurred with the initial dislocation. Can present rapidly or in a delayed fashion depending on the etiology.

Post–operative Rehabilitation

Week 1-5:

  • Repeat evaluation of the elbow stability is performed within 7-10 days following surgery. If the elbow is stable a program of gravity and active assisted elbow flexion and extension is begun.

  • Patients are given a removable posterior splint or elbow range of motion brace locked at 90 degrees, that is to be worn at all times except when performing elbow range of motion exercises. Patients are instructed to avoid varus stress on elbow.

  • Grip and forearm strengthening exercises are initiated but no lifting or use of the arm is permitted.

Week 6-12:

  • Elbow activity is permitted in a range of motion brace with lifting restriction of 1lb. Active range of motion exercises and forearm strengthening exercises are continued and light biceps and triceps strengthening exercises are initiated.

  • Lifting restrictions are kept until 3 months.

3 Months and beyond:

  • Assessment of fracture healing and elbow stability. If stable and fractures healed, patients are allowed to gradually increase activity level to full activity as tolerated.

  • Range of motion brace is discontinued.

  • Continued grip, forearm and elbow strengthening exercises are encouraged.

Outcomes/Evidence in the Literature

Doornberg, JN, Ring, DC. "Fracture of the anteromedial facet of the coronoid process". JBJS. vol. 88. 2006. pp. 2216-2224.

(Retrospective review of 18 patients with a fracture of the anteromedial facet of the coronoid. An associated lateral ligament injury was found in all but three of the patients. Surgical management was performed in 15 patients and fixation of the fractured anteromedial facet was performed in 11 patients. Healing of the fracture occurred in 12 patients, all of which had good or excellent results. The remaining six patients had varus subluxation and developed post-traumatic arthrosis and all had fair or poor results. The coronoid was treated surgically in two of the six with loss of fixation and the remaining four did not have specific fixation of the coronoid fracture. The authors concluded that secure fixation of an anteromedial coronoid fracture is important in preventing varus collapse and post-traumatic arthrosis.)

Forthman, C, Henket, M, Ring, D. "Elbow dislocation with intra-articular fracture: the results of operative treatment without repair of the medial collateral ligament". J Hand Surg. vol. 32. 2007. pp. 1200-1209.

(Retrospective review of 34 patients treated with open reduction and internal fixation or replacement of all fractures and repair of the lateral collateral ligament without repair of the medial collateral ligament. There were two cases of recurrent instability, both of which were attributed to post-operative non-compliance. Good or excellent results were obtained in 74% of patients with an average flexion arc of 120 degrees with 142 degrees of forearm rotation. Complications included five ulnar neuropathies and four patients with limited motion associated with heterotopic ossification. The authors concluded that if the intra-articular fractures and lateral collateral ligament are repaired the medial collateral ligament does not require repair or reconstruction.)

Mathew, PK, Athwal, GS, King, GJW. "Terrible triad injury of the elbow: current concepts". JAAOS. vol. 17. 2009. pp. 137-151.

(Review article summarizing the anatomy, pathology and treatment of terrible triad injuries of the elbow.)

Pugh, D. "Standard surgical protocol to treat elbow dislocations with radial head and coronoid fractures". JBJS. vol. 86. 2004. pp. 1122-1130.

(Retrospective review of 36 patients with terrible triad injuries treated with a standard surgical protocol and early range of motion. The surgical protocol involved fixation or replacement of the radial head, fixation of coronoid fractures if possible and repair of capsule and ligament injuries. Early range of motion was initiated between 1 and 2 weeks. The mean arc of motion was 112 degrees of flexion-extension and 136 degrees of forearm rotation. The mean Mayo Elbow Performance Score was 88 (45-100) with 15 excellent, 13 good, 7 fair and 1 poor result. Stability was restored in 34 of the 36 patients. There were eight reoperations, half of which were contracture release with hardware removal and the remainder were for synostosis, recurrent instability and infection.)

Pugh, D. "Standard surgical protocol to treat elbow dislocations with radial head and coronoid fractures: Surgical technique". JBJS. vol. 87. 2005. pp. 22-32.

(Description of the standardized surgical protocol used to treat terrible triad injuries of the elbow by the authors of the prior JBJS study. Technique starts with fixation of deep structures moving to superficial with a lateral approach. The coronoid or anterior capsule is repaired, followed by radial fixation or replacement. The lateral ligament complex is then repaired and stability assessed; if there is persistent instability the medial collateral ligament is repaired or an articulated external fixator is applied. An early range of motion protocol is initiated within 7-10 days after surgery.)

Rodriguez-Martin, J. "Outcomes after terrible triads of the elbow treated with current surgical protocols. A review". International Orthopaedics. 35. pp. 851-860.

(Review article of the results of terrible triad fracture dislocations of the elbow treated with current surgical protocols focusing on the fixation of all fractures and repair of the lateral collateral ligament. Five studies met the study criteria consisting of a total of 137 patients. The average flexion arc was 110 degrees and forearm rotation arc was 135 degrees. The average Mayo Elbow Performance score was 85 points. Complications included ulnar nerve symptoms, heterotopic ossification, contracture and post-traumatic arthritis.)

Summary

Complex dislocations of the elbow are challenging injuries to treat with historically poor outcomes. The recent advances in understanding and instrumentation have resulted in improved outcomes. The goal of treatment should be to do whatever is necessary to obtain elbow stability with rigid fixation of fractures to allow for early range of motion protocols. Patients should be informed of limitations of motion and risk of complications pre-operatively.

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