Newport: Nursemaids Elbow

Cases:

Patient #1: 18 month old boy who had been riding in the basket of a shopping cart. His older brother grabbed and pulled on his arm from inside the main part of the cart. He cried immediately and afterwards would not move the arm. Exam showed a crying, well-developed toddler holding his arm splinted to his body. The arm appeared normal with no swelling and was mildly tender to palpation diffusely. Reduction was attempted, child was left alone with family and after 10 minutes was happily eating a popsicle and using his arm. Magical. Re-exam showed no swelling and normal ROM. Pt was discharged within 20 minutes of arrival. The parents were profusely thankful. You leave the room feeling like a total rock star.

Patient #2: 2.5 year old girl who presented about 2 hours after a fall from a low stool. She was roughhousing with siblings and toppled onto the ground on her outstretched arm. She cried afterwards and then wouldn't move the arm. Mom was a military spouse and had 4 other children, 3 of whom had sustained nursemaid's elbows. She had learned the reduction maneuver and attempted to reduce it at home. The patient cried more and still wouldn't use the arm, so mom brought her to the ER. Exam showed a young girl holding her arm close to her body. The arm had very slight swelling at the distal humerus and was focally tender to palpation at the distal humerus only. Reduction was attempted but after 10 minutes she was still not using her arm. X rays were obtained and showed a non-displaced supracondylar fracture. You leave the room kicking yourself and wondering “why didn’t I just get x-rays.” Pt was sent to the local children’s hospital, casted, followed conservatively and had cast removed in 4 weeks.

Could this unfortunate situation been avoided? The good news is, probably yes.

Commonly referred to as nursemaid’s or pulled elbow, radial head subluxation is a common injury in toddlers. It occurs when longitudinal traction is placed on an extended and pronated arm. This position allows the annular ligament to catch between the radial head and the capitellum. It occurs slightly more often in girls and on the left side. It is usually a pulling mechanism (50%), but can be seen with falls, direct blow or twisting. In <6 months, MOI is usually rolling over. The most common scenario is an adult pulling abruptly up on the arm, such as tolift the child onto a sidewalk or step, or when the child abruptly falls/throws themselves to the ground while an adult is holding their arm (i.e. tantrum injury).

Nuresemaid’s is a clinical diagnosis. Children with suspected nursemaid’s generally hold the arm close to their bodies, with elbow extended or flexed/pronated. The arm should not be painful unless moved. The radial head may be tender, but the distal humerus should not be. Swelling is rare. Exam should palpate the entire extremity from clavicle to fingers if possible.

How to reduce? There are two methods: extension/supination and “forced” or hyperpronation.

Hyperpronation: Support elbow with finger at radial head giving mild pressure. Hold distal forearm and hyperpronate. 

Extension/supination: Support arm at elbow with finger at radial head. Pull traction on forearm, fully supinate then fully flex in a single movement.

Both methods are widely used and both work. Multiple studies have been done comparing the two methods.  The evidence is not overwhelming, but it appears pronation MAY have a slightly increased success rate and decreased perception of pain. So… Pronation may have the edge.

Nursemaid's Elbow Pearls:

• Entrapment or partial tearing of annular ligament
• 20-25% of elbow injuries in children
• 50% from pulling mechanism
• Most common ages 1-3
• Will not use arm
• Holding arm extended or slight flexion. Distal humerus is NOT tender but radial head may be.
• No swelling
• X-rays if: Swelling, unusual mechanism, tenderness to palpation over distal humerus, focal tenderness
• Differential: Supracondylar or buckle fracture
• Reduction maneuvers: Supination/flexion versus hyperpronation
• Hyperpronation may be less painful and have a slightly higher success rate

Faculty Reviewer:

Dr. Kristina McAteer 

References:

i. McDonald J, Whitelaw C, Goldsmith LJ. Radial head subluxation: comparing two methods of reduction. Acad Emerg Med. 1999;6(7):715. 

ii. Macias CG, Bothner J, Wiebe R. A comparison of supination/flexion to hyperpronation in the reduction of radial head subluxations. Pediatrics. 1998;102(1):e10. 

iii. Krul M, van der Wouden JC, van Suijlekom-Smit W, Koes BW. Manipulative interventions for reducing pulled elbows in young children. Cochrane Database Systematic Review. 2012 Jan 18;1.

iv. Coleman R, Reiland A. Chapter 28. Orthopedic Emergencies. In: Stone C, Humphries RL. eds. CURRENT Diagnosis & Treatment Emergency Medicine, 7e.New York, NY: McGraw-Hill; 2011. 

v. Green DA, Linares MY, Garcia Peña BM, et al. Randomized comparison of pain perception during radial head subluxation reduction using supination-flexion or forced pronation. Pediatr Emerg Care 2006; 22:235.

vi. Bexkens R, Washburn FJ, Eygendaal D, van den Bekerom MP, Oh LS. Effectiveness of reduction maneuvers in the treatment of nursemaid's elbow: a systematic review and meta-analysis. Am J Emerg Med. 2016 Nov 2 (epublished ahead of print )