Annular ligament displacement (ALD)— also termed radial head subluxation, nursemaid’s elbow, or pulled elbow—can be successfully diagnosed and treated over the telephone by properly trained medical professionals instructing nonmedical caretakers. Two case reports of successful ALD reduction via telephone are described. The pathology of ALD and techniques for its treatment are reviewed, and guidelines are given. The rationale for the introduction of the new term annular ligament displacement as well as areas for additional investigation are discussed. To our knowledge, this is the first published account of ALD reduction via telephone.
Nursemaid’s elbow or annular ligament displacement (ALD), formerly termed radial head subluxation, is a common pediatric orthopedic problem. It is most often seen in children between 1 and 4 years of age.1 This displacement usually occurs as the result of a sudden forceful longitudinal traction on the hand while the forearm is pronated and the elbow is extended, as when one lifts a child by the forearm or pulls the forearm of a resisting child.2
Nursemaid’s elbow is actually a displacement of the annular ligament between the capitulum of the distal humerus and the radial head.2 The radial head does not move out of its position relative to the capitulum. The annular ligament is displaced, from its normal position covering the radial head, into the radiohumeral joint. Radiographs of an untreated nursemaid’s elbow are normal without any evidence of abnormal positioning of the radial head. Ultrasound demonstrates that the space between the radial head and the capitulum of the humerus is increased in nursemaid’s elbow.3 This is presumably attributable to the interposition of the annular ligament into the radiohumeral joint.
Tachdjian2 describes how the specific anatomy of the radial head determines the pathophysiology of ALD: “The anterior part of the radial head elevates acutely from the radial neck, whereas the posterior and lateral parts of the radial head rise rather gradually (Fig 1). When longitudinal traction is applied on the wrist with the forearm in supination, the annular ligament is firmly held in place by the acute elevation of the radial head. When the forearm is in pronation, longitudinal traction on the wrist results in the annular ligament slipping over the radial head.”
The pathology of ALD occurs in 3 consecutive steps (Figs 2 and 3): 1) a transverse tear of the thin, relatively weak distal attachment of the annular ligament to the radial neck occurs, 2) the radial head then slides through the anterior portion of the annular ligament, and 3) the detached portion of the annular ligament slips over the radial head into the radiohumeral joint.4 Although there is a transient subluxation of the radial head, prolonged subluxation does not occur. It is the displacement of the annular ligament that causes the clinical picture of pain and immobility seen in nursemaid’s elbow. It is extremely rare for nursemaid’s elbow to occur in children over the age of 5 years. By this age, the annular ligament is thick and strong and unlikely to be torn and dislodged.
The introduction of the term annular ligament displacement is not a trivial semantic distinction. Annular ligament displacement accurately describes the pathophysiology of nursemaid’s elbow and allows for clear and precise evaluation, treatment, and additional study of this entity.
Supination or pronation of the forearm usually causes reduction of the annular ligament back into its normal position. The reported recurrence rate involving either the same or contralateral arm is extremely variable ranging from 5% to 39% depending on the referral population studied. An urban hospital emergency department (ED), in a prospective study, reported a recurrence rate of 24% which represents a good estimate of recurrence in the general population.5 Recurrence is thought to be secondary to laxity of the annular ligament. ALD reduction is almost always achieved by either the supination maneuver or the pronation maneuver.1–2,5–8
P.M. is a 4-year-old boy who was unable to move his right arm after an adult had swung him by his arms. He held his right arm partially flexed at the elbow. P.M. had a past medical history significant for three prior annular ligament displacements with ED reductions. There was no history of trauma or other medical conditions. The child’s pediatrician (R.E.K.) was called, and the case was discussed with him. The mother reported that there was no redness, swelling, bruising, or abnormal appearance of either the right shoulder, clavicle, or upper extremity. The fingertips of the right hand were reported to be pink and warm. The pediatrician discussed reduction with the child’s mother and uncle who was also in attendance. The mother deferred but the uncle agreed to attempt reduction with verbal instructions over the telephone. The child was placed on the mother’s lap facing outward. The child’s uncle was then given the following instructions: “This is what I want you to do. First, grasp your nephew’s right hand with your right hand. Now, place your left hand under his elbow to support it. Then straighten out his arm so the palm is facing upward. Then in one quick and fluid movement, swiftly bend his elbow up, and touch the palm of his hand to his same shoulder.” The instructions were clarified with the uncle and the maneuver was then performed. After the maneuver, the uncle reported that he “heard a pop.” The pediatrician called back in 10 minutes. The child was reported as “back to normal,” and was reaching his right arm over his head.
S.D. is a 20-month-old female who refused to use her left arm after playing outside with a babysitter. The child’s mother contacted her pediatrician (R.E.K.) en route to hospital. The mother was instructed to pull off the road to a safe location. The mother gave a further history that the babysitter had been attempting to get the child off their swing set. Six months before, the child had been treated at an ED for a nursemaid’s elbow. The mother was similarly questioned as to the condition of the child’s shoulder and arm, and was given the same instructions as in case 1. The child was restrained sufficiently by the car seat. The mother did not feel or hear a pop. After 10 minutes, the mother was called and reported that the child was moving her left arm “a little,” but not over her head. After 20 minutes, the child was reported as moving her arm normally, including reaching over her head.
Both cases described were successfully reduced in 1 attempt without any complications from the procedure. Parents of both of the children reported that they were very satisfied with the reduction and would again choose to treat the elbow over the telephone.
Neither family was billed for the telephone management. Each ED visit generates a facility’s charge and a professional fee. The combined charges for an ED visit for an annular ligament displacement is approximately $400 per visit. In addition, direct cost savings for many families is realized with elimination of the copayment for the ED visit.
These 2 cases demonstrate that a nonmedical caretaker under the guidance of a properly trained medical professional can safely reduce recurrent ALD.
The criteria used in selecting the proper patients for recurrent ALD reduction via telephone were the following: 1) history of previous ALD diagnosed and treated by a medical professional, 2) history consistent with acute recurrent ALD, 3) no history of other concomitant trauma requiring medical evaluation, and 4) confidence that the caretaker was competent and willing to attempt reduction via telephone.
Two maneuvers are commonly used when attempting to reduce ALD: supination or pronation (sometimes termed hyperpronation).6,7 Supination is simultaneous supination of the forearm and extension of the elbow, followed by flexion of the elbow as described in the case reports (Fig 4). A very effective pronation maneuver is termed the “handshake” maneuver.8 We have adapted the maneuver to include extension of the elbow, because we find it easier to perform. In this maneuver, one grasps the hand of the patient’s affected arm as if to shake it. The other hand is placed under the affected elbow. The patient’s forearm is then simultaneously pronated and the elbow is extended. The elbow is then flexed with the forearm maintained in pronation to complete the maneuver (Fig 5).
Initial attempts at reduction are usually successful. Failure may be attributable to improper reduction technique. Failure may also occur because of local swelling or a small hemorrhage in the region of the annular ligament.1 Failure is also more likely to occur if reduction is attempted 12 or more hours after ALD has occurred. In rare situations, reduction may fail because the annular ligament has been completely torn from its distal attachment to the radial neck. Failure is apparent if the child continues to have pain and refuses to use the forearm an hour after reduction maneuvers have been attempted. In the event of failure, orthopedic consultation is indicated. The usual orthopedic treatment is immobilization by posterior splinting.2 The elbow is splinted at 90° flexion with as much supination of the forearm as comfort will allow. The splint is usually applied for 10 to 14 days. Self-reduction almost always occurs during the period of immobilization.
There has been much debate in the literature as to which maneuver, supination or pronation, is more effective. Although both maneuvers are highly effective, it seems that pronation is more effective.7 The optimal approach is supination followed by pronation when supination fails. Supination was used in our telephone case studies because it was felt to be easier to implement. (In our practice (R.E.K.), we typically perform the supination maneuver twice, wait 30 minutes, and then perform the pronation maneuver twice if supination has been unsuccessful.)
Important issues for future investigation remain. Can future episodes of ALD be systematically treated via telephone following an initial ALD reduction and parent education in the office or ED setting? Can the first episode of ALD be accurately diagnosed and safely treated via telephone?
The medical legal issues regarding telephone treatment for ALD need to be addressed. Inappropriate treatment of a fracture poses the biggest challenge in suspected ALD. Fractures have been reported in 6% of patients presenting to a hospital ED for suspected ALD. We feel that the health care provider has no additional medical legal liability in telephone treatment of recurrent ALD provided that the practitioner follows the criteria and guidelines described, is convinced that the likelihood of a fracture is minimal, and proceeds in a prudent fashion. It is probable that medical practitioners are already treating ALD, recurrent and even initial episodes, via telephone, and this practice has simply not been documented to date in the medical literature. Telephone treatment of ini-tial ALD requires additional study before safety and efficacy can be determined.
We are indebted to Elaine Mosher, MLS, for her assistance in the preparation of the manuscript.
- Received September 6, 2001.
- Accepted February 15, 2002.
- Reprint requests to (K.A.L.) Division of Emergency Medicine, Children’s Hospital of Buffalo, 219 Bryant St, Buffalo, NY 14222. E-mail:
- ↵Tachdjian MO. Clinical Pediatric Orthopedics. Stamford, CT: Appleton and Lange; 1997
- ↵Kosuwon W, Mahaisavariya B, Saengnipanthkul S, Laupattarakasem W, Jirawipoolwon P. Ultrasonography of pulled elbow. J Bone Joint Surg.1993;75B :421– 422
- ↵Jones J, Cote B. “Irreducible” nursemaid’s elbow. Am J Emerg Med.1995;13 :491
- ↵Macias CG, Bothner J, Wiebe R. A comparison of supination/flexion to hyperpronation in the reduction of radial head subluxations. Pediatrics.1998;102(1) . Available at: http://www.pediatrics.org/cgi/content/full/102/1/e10
- ↵Lyver MB. Radial head subluxation. J Emerg Med.1990;8 :154– 155
- Copyright © 2002 by the American Academy of Pediatrics