A 7-year-old girl with right elbow pain

Issue: February 2017

ByJeffrey D. Ackman, MD

ByBryan M. Saltzman, MD

ByMatthew W. Tetreault, MD

A healthy 7-year-old, right-hand dominant girl who sustained a right elbow injury 1 year prior presented to our office. She was seen immediately following the injury at an outside hospital emergency department where she was diagnosed with an ulnar shaft fracture and placed into a splint (Figure 1). She followed up with an outside institution’s orthopedic surgeon who treated her injury with close monitoring in a cast.

After several weeks of immobilization and demonstration of radiographic union, she began physical therapy. However, this was difficult and painful for her. A few months later upon repeat evaluation, it was noted she had a dislocated radial head with a presumed missed Monteggia fracture-dislocation at the time of her original injury. Three months after her injury, she underwent open reduction of the right radiocapitellar joint through a lateral Kocher approach, primary annular ligament repair and pinning of the radiocapitellar joint with a K-wire. After several weeks of postoperative immobilization with casting and a pin in place, she underwent removal of the pin and began physical therapy. Given her pain after this first procedure, she presented to our office for a second opinion at 9 months postoperatively; this was 1 year after the initial injury.

Upon presentation, she had no motor or sensory deficits, but complained of range of motion (ROM) deficits when compared to the contralateral side. She showed no significant swelling on exam with ROM from 0° to 90° of flexion (vs. -5° to 140° of flexion on the unaffected side) and lacked 5° of supination and 40° of pronation when compared to the unaffected side (Figure 2). Her neurovascular exam was normal.

Radiographs at time of injury — Shown are anteroposterior (a), lateral (b) and oblique (c) radiographs of the right elbow and an anteroposterior (d) radiograph of the right forearm at initial time of injury 1 year prior to presentation at our office. Note the Monteggia fracture-dislocation, with apex anterior angulation of the ulnar shaft and anterior dislocation of the radial head. While the ulnar shaft fracture was treated after injury, the radiocapitellar joint dislocation was not identified initially.

What is your diagnosis?

At presentation to our office, these anteroposterior (a) and lateral (b) radiographs were taken. This was 9 months after primary repair of the annular ligament and pinning of the radiocapitellar joint was done by an outside orthopedic surgeon. These demonstrate persistence of radial head anterior dislocation, with an ulnar shaft fracture malunion with apex anterior angulation.

See answer on next page.

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Failure of annular ligament repair with recurrent radiocapitellar dislocation

Despite operative intervention, the patient sustained a recurrent and persistent dislocation of her radial head. In addition, it was noted that she had apex anterior angulation of her otherwise healed ulnar shaft fracture. Italian surgeon Giovanni Battista Monteggia, MD, was the first to describe a fracture of the shaft of the ulna and an associated anterior dislocation of the radial head. This was further expanded upon to include four combinations of proximal ulnar fractures accompanied by radial head dislocations, which is commonly known today as the Bado classification. The direction of the radial head dislocation typically dictates the direction of the apex of the ulnar fracture. In what has been eponymously named the Monteggia fracture-dislocation, the injury pattern causes the annular and quadrate ligaments to rupture, leading to dislocation of both the proximal radioulnar and radiocapitellar joints. However, as the more distal soft-tissue structures remain intact, anatomic reduction of the fractured ulna typically leads to reduction of the radiocapitellar and proximal radioulnar joints.

While forearm fractures are common in children and represent about 20% to 30% of all fractures in this age demographic, Monteggia fracture-dislocations are relatively rare and account for only 1% of pediatric forearm fractures. Estimates suggest that about 25% to 50% of these injuries are initially missed due to lack of expertise from the providing physician and misdiagnosed as isolated ulnar shaft fractures. Chronic dislocation of the radial head is poorly tolerated and results in elbow stiffness, persistent pain, cubitus valgus, tardy ulnar nerve palsy and valgus instability.

Intraoperative fluoroscopic imaging of the forearm demonstrating passage of the smooth pin to the site of the ulnar osteotomy (a) and through the osteotomy site (b) are shown. Also shown is the final intraoperative fluoroscopic imaging of the elbow, with the radial head reduced and ulnar pin in place (c).

Management

Radiographs 14-weeks postoperatively — Anteroposterior (a) and lateral (b) forearm radiographs at 14-weeks postoperatively demonstrate maintenance of radiocapitellar joint reduction and callus formation ulnar osteotomy site.

Prior to any intervention, the patient’s age, functional demands and mechanism of injury must be noted. Clinical evaluation should include a thorough neurologic examination. In the acute setting, an attempt at closed reduction and immobilization of the ulnar fracture and radial head dislocation is appropriate when the fracture is without significant angulation and the radial head is anatomically reduced. These patients should be closely monitored to be certain the radiocapitellar joint remains reduced. When operative intervention is required to address the injury pattern, closed or open reduction with internal fixation of the ulna, closed radial head reduction and early rehabilitation is first employed. Anatomic reduction of the ulna is important to ensure stable, concentrically reduced radiocapitellar and radioulnar joints and often results in a spontaneous reduction of the radial head. If the radial head fails to reduce, there is inadequate reduction of the ulnar fracture or interposition of soft tissues (capsule, annular ligament, nerve, osteochondral fragments).

In the chronic setting — as with a missed or neglected Monteggia fracture-dislocation — conservative management is not an option, as the patient will unlikely regain functional ROM. Surgical intervention options include any of the following in isolation or combination: open reduction and annular ligament reconstruction; open reduction and ulnar osteotomy; radial osteotomy; or radial head excision. Most commonly, annular ligament reconstruction is incorporated as part of the treatment, and the use of triceps fascia, triceps tendon, annular ligament remnant, forearm fascia, palmaris longus or ulnar periosteum have been described for use as graft. Osteotomy of the ulna can be performed at the proximal ulnar metaphysis or at the previous fracture site. If the radiocapitellar articulation is still felt to be unstable intraoperatively, transcapitellar K-wires can augment the reduction temporarily.

Treatment

This patient underwent an open reduction of the right radiocapitellar joint, distraction osteotomy of the right ulna and reconstruction of the annular ligament using a slip of the triceps fascia (modified Bell-Tawse procedure). The patient was placed under general anesthesia, and a longitudinal incision was made in the posterior aspect of the arm in the midline of the triceps. The incision curved around the olecranon laterally, where a skin flap was raised and the joint capsule exposed. As expected, the radial head demonstrated morphologic changes from longstanding dislocation. Soft tissues interposed within the joint were removed with a rongeur, and a reduction was attempted. In flexion and supination, the radiocapitellar joint appeared reduced, but it redislocated with elbow extension. Thus, a decision was made to perform an ulnar distraction osteotomy.

A longitudinal incision was made over the subcutaneous border of the ulna. A transverse osteotomy was made at the maximal bow of the deformity. A smooth pin was placed down the shaft of the ulna, starting at the proximal olecranon and passing to the osteotomy site (Figure 3a). With the osteotomy held in an appropriate reduced position, the pin was advanced across the osteotomy site (Figure 3b). Attention was turned back to the radial head for performance of the annular ligament reconstruction. A slip of triceps fascia was harvested from the lateral aspect of the triceps (approximately 1 cm in width) and run with Ethibond suture (Ethicon). A small drill hole was made in the proximal ulna to allow the passage of the sutures. The triceps slip was then passed under the anconeus and around the radial head from posterior to anterior using a curved six, passed back under the anconeus and buried into the drill hole placed in the ulna. The construct was tensioned properly over the well-reduced radial head, and the sutures tied over the periosteal bone bridge.

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Postoperative care

The patient was placed in a cast in 90° of flexion and full supination, with fluoroscopic imaging confirming maintained reduction of the radial head (Figure 3c). At 6-weeks postoperatively, her cast was removed and she was allowed to begin gentle ROM exercises. At 8-weeks postoperatively, the pin in her ulna was removed and her motion and rehabilitation restrictions were advanced. At 14-weeks postoperatively, she had maintenance of radiocapitellar reduction, the osteotomy site continued to show interval callus formation and healing (Figure 4) and she was released to normal daily activities. She had full flexion and lacked approximately 20° of terminal extension and 10° of pronation in comparison with the contralateral side — a significant improvement from her preoperative deficits.

In most studies reporting on the modified Bell-Tawse annular ligament reconstruction, postoperative casting is used to protect the reduction and the duration of cast use varies from 2 weeks to 8 weeks. Casting is done in supination, where the radiocapitellar joint is most stable or in neutral in an attempt to minimize deficits in forearm pronation. Published results for this procedure are limited, but have demonstrated improved ROM arcs and functionality at several years postoperatively, despite some patients experiencing persistent loss of pronation/supination or recurrent, asymptomatic radial head subluxation.

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For more information:
Bryan M. Saltzman, MD; and Matthew W. Tetreault, MD, can be reached at the Department of Orthopaedic Surgery, Rush University Medical Center, 1611 W. Harrison St., Ste. 300, Chicago, IL 60612; Saltzman’s email: bryan.m.saltzman@gmail.com; Tetreault’s email: matthew.w.tetreault@gmail.com.
Jeffrey D. Ackman, MD, can be reached at the Department of Orthopaedic Surgery, Shriner’s Hospital for Children, 2211 N. Oak Park Ave., Chicago, IL 60707; email: jdackman@shrinenet.org.

Disclosures: Saltzman reports he receives royalties from Nova Science Publishers and honorarium from Postgraduate Institute for Medicine. Ackman reports he is a paid presenter for Smith & Nephew. Tetreault reports no relevant financial disclosures.