Medial epicondylar fractures of the humerus

In this section, we will mainly discuss medial epicondylar fractures. Medial condylar fractures are a rare fracture pattern and are managed similarly to lateral condylar fractures. Therefore, it is important to differentiate between medial condylar and epicondylar fractures. Condylar fractures are intra-articular and require urgent open reduction and internal fixation.

Margot is 12 years old and a keen gymnast. She was practising on the uneven bars and had a sudden pain in the medial aspect of her right arm during a twisting manoeuvre.  She attended the local Emergency Department, where she was told that she had an avulsion fracture of the medial epicondyle of her humerus.

Epidemiology

Medial epicondylar fractures are the third most common elbow fracture type in children. They are most likely to occur in children 9-14 years old and more common in boys.

History

The child will complain of pain in the medial aspect of the elbow.

This type of fracture occurs due to excessive valgus stress causing strain at the origin of the common flexor tendon (for those of you who remember your anatomy, that’s the common origin point of flexor carpi ulnaris, flexor carpi radialis, palmaris longis, pronator teres and flexor digitorum superficialis). It most commonly occurs due to a fall onto outstretched arm during valgus stress and is frequently (up to 50% of cases) associated with posterior elbow dislocation. Sporting activities which involve repetitive throwing, and gymnastics, are associated with a higher frequency of medial epicondylar fractures. The fracture is often known as “little league elbow”.

Examination

Inspection will reveal swelling to the medial aspect of the elbow. If there is more generalised swelling, this suggests elbow dislocation. Bruising to the medial aspect may be present, especially when the injury mechanism involves direct trauma.

Valgus instability of the joint is common and careful examination and documentation of neurovascular status is imperative.

The ulnar nerve is the most vulnerable neurovascular structure in this type of injury. Look at the elbow examination post for tips and tricks in examination of the neurovascular status of the limb.

Investigations

An AP and lateral X-ray should be arranged. If other fractures are suspected, these areas should also be x-rayed.

50% of medial epicondylar fractures are associated with elbow dislocation. These often spontaneously reduce, and 15% of these will have the epicondyle trapped (“incarcerated”) within the joint. This incarceration may also occur iatrogenically on reduction of the joint.

CRITOE comes into play here. The medial (or “internal”) epicondyle is the third ossification to appear and the final centre to fuse at 16-18 years old. The internal (medial) epicondyle never develops before the trochlea. So if you can identify the trochlea but no medial epicondyle, the medial epicondyle is within the joint.

It is important to identify medial condylar from epicondylar fractures here as condylar fractures are intra-articular and require urgent orthopaedic review.

Classification

Medial epicondylar fractures are extra-articular. They can be classified according to the degree of displacement of the epicondyle, its association with elbow dislocation and incarceration of the epicondyle within the joint on reduction of the dislocation. Precise measurement of the degree of displacement of the medial epicondyle is important as this helps to decide the optimum management.

Immediate treatment in the ED

Provide immediate adequate analgesia to the child prior to any examination or investigation.

If the fracture is open, conservatively manage the wound, consider tetanus status and antibiotics.

Keep the child nil by mouth as they may need urgent surgery.

Treatment following imaging

In cases where displacement is 5-15mm, treatment opens are dependent on a number of factors:

• Age: (<8 conservative, >8 ORIF)
• Level of sporting activity (nil: treat conservatively, active athlete involving valgus stress (e.g. thrower / gymnast) treat with ORIF)
• Hand dominance (if non-dominant hand: treat conservatively, dominant hand: manage with ORIF)

A dislocated elbow requires urgent closed reduction.

This can be performed in the paediatric emergency department with safe procedural sedation. Re-imaging the elbow following reduction is important to look for incarceration of the medial epicondyle within the joint.

When the medial epicondyle is incarcerated, whether spontaneous or following reduction, it must be reduced in theatre by open reduction followed by internal fixation. While the reduction must be performed urgently, a study by Vuillerman et al., 2017 showed that time to theatre (15-40 hours) did not have deleterious effects on the outcome. Therefore the procedure needn’t be performed overnight.

Areas of controversy

Medial epicondyle fractures associated with elbow dislocation do not necessarily require open reduction and internal fixation. A systematic review by Knapik et al., 2017 found that, in the absence of absolute surgical indication, non-operative management of an isolated fracture of the medial epicondyle appeared to have similar outcomes whether or not it was associated with a dislocation. The evidence base, however, is poor, and there are studies which support both arguments.

To clarify this controversy, we may soon have access to high-quality evidence towards the best management for these fractures. SCIENCE – Surgery or Cast for Injuries of the EpicoNdyle in Children’s Elbows is a multi-centre prospective randomised superiority trial studying operative fixation versus nonoperative treatment for medial epicondyle fractures of the humerus in children. This trial is underway and is led by Prof Dan Perry and sponsored by the University of Oxford. The study will compare the two common treatments for medial epicondyle fractures: 1) Conservative management with plaster for up to four weeks and 2) Open fixation followed by resting the arm in a splint or cast for up to 4 weeks. Recruitment is underway and is planned to complete on 31/05/2021 with the study period ending 31/08/2027. The primary objective of the study is to quantify and draw inferences on observed differences in function between the two groups using the Patient Reported Outcomes Measurement Information System (PROMIS) Upper Extremity Score for Children at 1 year post-randomisation for fractures of the medial epicondyle. We will look forward to the results!

Potential complications

• Non-union may occur and is much more likely in non-surgically managed patients. It is, however, generally asymptomatic.
• Nerve injury is usually a neuropraxia to the ulnar nerve and most resolve spontaneously. Radial nerve injury may occur iatrogenically.
• Stiffness of the elbow joint. This is worse when dislocation has occurred.

Danger signs

Remember CRITOE! If there is a trochlea present but no internal (medial) epicondyle in its anatomical location, then look for it. It is likely incarcerated in the joint.

Margot had a 10mm displacement of her medial epicondyle. There was no elbow dislocation. Her ulnar nerve was intact on examination. The treating orthopaedic team decided to opt for ORIF, and she went to theatre the next morning and went home that afternoon with an orthopaedic follow up.

References

Beck JJ, Richmond CG, Tompkins MA, Heyer A, Shea KG, Cruz AI Jr. What’s New in Pediatric Upper Extremity Sports Injuries? J Pediatr Orthop. 2018 Feb;38(2):e73-e77. doi: 10.1097/BPO.0000000000001104. Review. PubMed PMID:29117014.

Bowden G, McNally MA, Thomas RYW, Gibson A, Oxford Handbook of Orthopaedics and Trauma,2013. Elbow injuries in children 2, page 566

Knapik DM, Fausett CL, Gilmore A, Liu RW. Outcomes of Nonoperative Pediatric Medial Humeral Epicondyle Fractures With and Without Associated Elbow Dislocation. J Pediatr Orthop. 2017 Jun;37(4):e224-e228. doi: 10.1097/BPO.0000000000000890. Review. PubMed PMID: 27741036.

Orthobullets: https://www.orthobullets.com/pediatrics/4008/medial-epicondylar-fractures–pediatric?expandLeftMenu=true

Royal Children’s Hospital Melbourne: https://www.rch.org.au/clinicalguide/guideline_index/fractures/Medial_epicondyle_emerg/

Saeed W, Waseem M. Elbow Fractures Overview. 2019 Jan 20. StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2019 Jan-. Available from PMID: 28723005.

Vuillermin C, Donohue KS, Miller P, et al. Incarcerated medial epicondyle fractures with elbow dislocation: risk factors associated with morbidity. J Pediatr Orthop. 2017. [Epub ahead of print]. [Context Link]