A case of pediatric medial epicondyle fracture with medial and lateral collateral ligament injury

Medial epicondyle fractures account for approximately 10% of pediatric elbow periarticular fractures, with the peak incidence occurring at around 11-12 years of age.1Beck J.J. Bowen R.E. Silva M. What's new in pediatric medial epicondyle fractures?.J Pediatr Orthop. 2018; 38: e202-e206https://doi.org/10.1097/BPO.0000000000000902Crossref PubMed Scopus (30) Google Scholar,3Gottschalk H.P. Eisner E. Hosalkar H.S. Medial epicondyle fractures in the pediatric population.J Am Acad Orthop Surg. 2012; 20: 223-232https://doi.org/10.5435/JAAOS-20-04-223Crossref PubMed Scopus (122) Google Scholar,10Pathy R. Dodwell E.R. Medial epicondyle fractures in children.Curr Opin Pediatr. 2015; 27: 58-66https://doi.org/10.1097/MOP.0000000000000181Crossref PubMed Scopus (48) Google Scholar It has been reported that they develop due to various injury mechanisms such as a direct blow, avulsion, and dislocation, and that the applied external force causes characteristic lesions such as radial head fracture, coronoid fracture, and ligament injury.2Fowles J.V. Slimane N. Kassab M.T. Elbow dislocation with avulsion of the medial humeral epicondyle.J Bone Joint Surg Br. 1990; 72: 102-104Crossref PubMed Google Scholar,13Stans AA, Lawrence JTR. Rockwood and Wilkins' Fractures in Children. 8th ed. Philadelphia, PA: Wolters Kluwer; 2015:651-700.Google Scholar Conservative approaches have traditionally been favored for the treatment of medial epicondyle fractures due to the fact that pseudarthrosis typically does not result in significant symptoms.5Kim B.S. Park K.H. Song H.S. Park S.Y. Ligamentous repair of acute lateral collateral ligament rupture of the elbow.J Shoulder Elbow Surg. 2013; 22: 1469-1473https://doi.org/10.1016/j.jse.2013.06.018Abstract Full Text Full Text PDF PubMed Scopus (49) Google Scholar,13Stans AA, Lawrence JTR. Rockwood and Wilkins' Fractures in Children. 8th ed. Philadelphia, PA: Wolters Kluwer; 2015:651-700.Google Scholar However, in recent years, there have been reports recommending surgery to facilitate early return to sports and prevent delayed ulnar nerve paralysis.1Beck J.J. Bowen R.E. Silva M. What's new in pediatric medial epicondyle fractures?.J Pediatr Orthop. 2018; 38: e202-e206https://doi.org/10.1097/BPO.0000000000000902Crossref PubMed Scopus (30) Google Scholar,3Gottschalk H.P. Eisner E. Hosalkar H.S. Medial epicondyle fractures in the pediatric population.J Am Acad Orthop Surg. 2012; 20: 223-232https://doi.org/10.5435/JAAOS-20-04-223Crossref PubMed Scopus (122) Google Scholar,4Kamath A.F. Cody S.R. Hosalkar H.S. Open reduction of medial epicondyle fractures: operative tips for technical ease.J Child Orthop. 2009; 3: 331-336https://doi.org/10.1007/s11832-009-0185-6Crossref PubMed Scopus (27) Google Scholar,10Pathy R. Dodwell E.R. Medial epicondyle fractures in children.Curr Opin Pediatr. 2015; 27: 58-66https://doi.org/10.1097/MOP.0000000000000181Crossref PubMed Scopus (48) Google Scholar,13Stans AA, Lawrence JTR. Rockwood and Wilkins' Fractures in Children. 8th ed. Philadelphia, PA: Wolters Kluwer; 2015:651-700.Google Scholar Nevertheless, the choice of treatment remains controversial, and decisions are often made on a case-by-case basis, with consideration of the patient's activity level. Few reports have focused on the complications of medial epicondyle fractures and their treatment.6Mitchelson A.J. Gabriel K.R. Medial Epicondyle Fracture With Concomitant Flexor-Pronator Mass Avulsion From the Fracture Fragment A Case Report.JBJS Case Connect. 2020; 10e0417https://doi.org/10.2106/JBJS.CC.19.00417Crossref Scopus (0) Google Scholar,7Morimoto T. Izumi M. Ueba H. Ikeuchi M. Humeral Avulsion of the Lateral Collateral Ligament of the Elbow Concomitant with the Medial Epicondyle Fracture of a Child with General Joint Laxity.Case Rep Orthop. 2019; 41965343https://doi.org/10.1155/2019/1965343Crossref Google Scholar Dislocation is a relatively common mechanism of injury in medial epicondyle fractures, but there is a risk that elbow joint instability associated with complications such as collateral ligament injuries may be overlooked if the dislocation is spontaneously reduced. This report describes a case of medial epicondyle fracture with elbow instability, complicated by bilateral ligamentous injuries. The patient was a 14-year-old male who was injured by putting his hand out when thrown during a judo match. He visited a local hospital with the chief complaint of right elbow pain and was diagnosed with a medial epicondyle fracture. The patient was referred to our hospital for further treatment. There was swelling of the entire elbow and tenderness at the medial and lateral humeral condyles, but no motor or sensory deficits distal to the elbow joint. Imaging studies revealed a medial epicondyle fracture and subluxation of the humeroulnar joint (Fig 1a–d). The physical and imaging findings suggested a medial epicondyle fracture combined with a medial collateral ligament (MCL) and lateral collateral ligament (LCL) injury that would have caused elbow instability. Surgery was performed on the fourth day post-injury under general anesthesia in the supine position. Initially, elbow joint stability was assessed. The elbow joint was dislocated posteriorly with extension beyond 45°, and during valgus and varus stress tests, both the humeroulnar and humeroradial joints opened more than 20° (Fig 2 a–d). Valgus and varus stress tests both revealed no clear endpoint, indicating a high degree of instability. The flexor muscles were found to be attached to the medial epicondyle bone fragments, and inversion of the bone fragment revealed a bare medial condyle of the humerus with detachment of the MCL (Fig 3-a). We considered that there was a complication of MCL injury, but due to the high degree of instability of the elbow joint, we prioritized bone fragment fixation, which allows firm stabilization. The medial epicondyle fragment was reduced while being pulled centrally and fixed with tension band wiring (1.8 mm Kirschner wire × 2, and 0.81-mm soft wire × 1). Instability associated with elbow extension persisted after osteosynthesis. In addition, a valgus stress test revealed that the humeroulnar joint opened approximately 20° and there was no endpoint, indicating that valgus instability remained (Fig 3-b). Therefore, LCL and MCL repairs were performed. The extensor muscles and LCL were detached from the lateral condyle of the humerus, and the lateral condyle of the humerus was bare, similar to the medial side [Fig 4-a]. The extensor muscles and LCL were repaired using a φ1.4 mm JuggerKnot (Zimmer Biomet, Warsaw, IN, USA). After LCL repair, the instability in elbow extension and varus stress improved (Fig 4-b). For MCL repair, the flexor muscles attached to the medial epicondyle fragment were carefully avoided in the direction of the flexor fibers. The MCL, detached from the humeral side, was identified [Figure 5-a]. Similar to the LCL, repair was performed using a φ1.4 mm JuggerKnot (Zimmer Biomet, Warsaw, IN, USA). After MCL repair, instability against valgus stress improved (Figure 5-b). Postoperative radiography showed good reduction (Fig 6-a, b).Figure 3(a) Medial humeral condyle without muscle or ligament attachment. Arrow indicates the ulnar nerve. Arrowhead indicates the medial epicondyle fragment. (b) Valgus stress after osteosynthesis.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Figure 4(a) The extensor muscles and LCL were detached from the lateral condyle of the humerus. (b) Varus stress after LCL repair.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Figure 5(a) The flexor muscles were avoided in the direction of the fibers. Arrow indicates the MCL detached from the humerus. (b) Valgus stress during after MCL repair.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Figure 6(a) Plain X-ray, anteroposterior view. (b) Plain X-ray lateral view.View Large Image Figure ViewerDownload Hi-res image Download (PPT) Postoperatively, joint mobilization exercises were conducted under elbow joint extension restriction to -20° using an elbow joint orthosis. The orthosis was discontinued 6 weeks after surgery, and the extension restriction was lifted. Four months post-surgery, bone union was confirmed, and the implants used for osteosynthesis were removed. Elbow joint stability was evaluated at the time of implant removal. Good stability was obtained with elbow extension, valgus, and varus stress (Fig 7 a–c). At six months postoperatively, the automatic range of motion of the elbow joint was extension 0°/flexion 135° (5°/135° on the healthy side) with mild residual extension restriction. The patient was able to resume daily and judo activities successfully, despite a slight difference in grip strength between the affected and unaffected sides. At ten months after surgery, the grip strength of the affected side was 28 kg, while that on the unaffected side was 32 kg. Three injury mechanisms have been reported for medial epicondyle fractures: direct blow, avulsion, and dislocation.2Fowles J.V. Slimane N. Kassab M.T. Elbow dislocation with avulsion of the medial humeral epicondyle.J Bone Joint Surg Br. 1990; 72: 102-104Crossref PubMed Google Scholar,13Stans AA, Lawrence JTR. Rockwood and Wilkins' Fractures in Children. 8th ed. Philadelphia, PA: Wolters Kluwer; 2015:651-700.Google Scholar A direct blow is considered to be a rare mechanism of injury.13Stans AA, Lawrence JTR. Rockwood and Wilkins' Fractures in Children. 8th ed. Philadelphia, PA: Wolters Kluwer; 2015:651-700.Google Scholar Avulsion is the most common mechanism and typically occurs because of valgus stress on an outstretched hand, although arm wrestling and throwing are thought to involve similar mechanisms.8Lokiec F. Velkes S. Engel J. Avulsion of the medial epicondyle of the humerus in arm wrestlers: a report of five cases and a review of the literature.Injury. 1991; 22: 69-70Abstract Full Text PDF PubMed Scopus (21) Google Scholar,9Osbahr D.C. Chalmers P.N. Frank J.S. Williams III, R.J. Widmann R.F. Green D.W. Acute, avulsion fractures of the medial epicondyle while throwing in youth baseball players: a variant of Little League elbow.J Shoulder Elbow Surg. 2010; 19: 951-957https://doi.org/10.1016/j.jse.2010.04.038Abstract Full Text Full Text PDF PubMed Scopus (48) Google Scholar Dislocation is also frequent, occurring in 30-55% of medial epicondyle fractures, and cadaveric biomechanical studies have reported that it occurs when rotational force is accompanied by valgus or varus stress.7Morimoto T. Izumi M. Ueba H. Ikeuchi M. Humeral Avulsion of the Lateral Collateral Ligament of the Elbow Concomitant with the Medial Epicondyle Fracture of a Child with General Joint Laxity.Case Rep Orthop. 2019; 41965343https://doi.org/10.1155/2019/1965343Crossref Google Scholar,13Stans AA, Lawrence JTR. Rockwood and Wilkins' Fractures in Children. 8th ed. Philadelphia, PA: Wolters Kluwer; 2015:651-700.Google Scholar The pathology of this case was initially inferred from the physical and imaging findings, but later a video of the judo match was provided by the parents. It was confirmed from the video that when the patient placed his hand on the floor with his elbow extended, the opponent's weight was applied to his upper extremity, applying a strong force in the direction of elbow valgus and hyperextension, which led to dislocation. Medial epicondyle fractures can be complicated by periarticular elbow fractures and ligamentous injuries, and it is important not to overlook them during the diagnosis. Complications of radial head fracture and MCL injury have been reported in avulsion, while complications of coronoid fracture, radial head fracture, and MCL or LCL injury have been reported in dislocation.2Fowles J.V. Slimane N. Kassab M.T. Elbow dislocation with avulsion of the medial humeral epicondyle.J Bone Joint Surg Br. 1990; 72: 102-104Crossref PubMed Google Scholar,6Mitchelson A.J. Gabriel K.R. Medial Epicondyle Fracture With Concomitant Flexor-Pronator Mass Avulsion From the Fracture Fragment A Case Report.JBJS Case Connect. 2020; 10e0417https://doi.org/10.2106/JBJS.CC.19.00417Crossref Scopus (0) Google Scholar,7Morimoto T. Izumi M. Ueba H. Ikeuchi M. Humeral Avulsion of the Lateral Collateral Ligament of the Elbow Concomitant with the Medial Epicondyle Fracture of a Child with General Joint Laxity.Case Rep Orthop. 2019; 41965343https://doi.org/10.1155/2019/1965343Crossref Google Scholar,13Stans AA, Lawrence JTR. Rockwood and Wilkins' Fractures in Children. 8th ed. Philadelphia, PA: Wolters Kluwer; 2015:651-700.Google Scholar However, in case of spontaneous reduction of dislocation such as in this case, it should be noted that complications such as ligamentous injuries may be overlooked. MRI is sometimes required to diagnose ligamentous injuries, which are difficult to evaluate by X-ray or CT. However, this procedure is time-consuming and may require sedation in young patients. Although MRI was not performed in this case, we inferred a complication of ligamentous injury based on the physical findings and subluxation of the elbow joint on CT. CT was performed with the shoulder joint flexed and in external rotation, which may have induced elbow instability. However, the treatment of medial epicondyle fractures remains controversial. Pseudarthrosis is a concern in cases of bone-fragment displacement. However, there is no consensus in the literature regarding the amount of displacement suitable for surgery (e.g., 2 mm, 5 mm, or ≥10 mm).11Pezzutti D. Lin J.S. Singh S. Rowan M. Samora J.B. Pediatric Medial Epicondyle Fracture Management: A Systematic Review.J Pediatr Orthop. 2020; 40: e697-e702https://doi.org/10.1097/BPO.0000000000001532Crossref PubMed Scopus (27) Google Scholar,13Stans AA, Lawrence JTR. Rockwood and Wilkins' Fractures in Children. 8th ed. Philadelphia, PA: Wolters Kluwer; 2015:651-700.Google Scholar Many reports support conservative treatment because most cases are not symptomatic, although approximately 70% show pseudarthrosis when treated conservatively.1Beck J.J. Bowen R.E. Silva M. What's new in pediatric medial epicondyle fractures?.J Pediatr Orthop. 2018; 38: e202-e206https://doi.org/10.1097/BPO.0000000000000902Crossref PubMed Scopus (30) Google Scholar,3Gottschalk H.P. Eisner E. Hosalkar H.S. Medial epicondyle fractures in the pediatric population.J Am Acad Orthop Surg. 2012; 20: 223-232https://doi.org/10.5435/JAAOS-20-04-223Crossref PubMed Scopus (122) Google Scholar,4Kamath A.F. Cody S.R. Hosalkar H.S. Open reduction of medial epicondyle fractures: operative tips for technical ease.J Child Orthop. 2009; 3: 331-336https://doi.org/10.1007/s11832-009-0185-6Crossref PubMed Scopus (27) Google Scholar,11Pezzutti D. Lin J.S. Singh S. Rowan M. Samora J.B. Pediatric Medial Epicondyle Fracture Management: A Systematic Review.J Pediatr Orthop. 2020; 40: e697-e702https://doi.org/10.1097/BPO.0000000000001532Crossref PubMed Scopus (27) Google Scholar,13Stans AA, Lawrence JTR. Rockwood and Wilkins' Fractures in Children. 8th ed. Philadelphia, PA: Wolters Kluwer; 2015:651-700.Google Scholar On the other hand, there are some reports recommending surgery to speed up return to sports and to prevent delayed ulnar neuropathy in cases of pseudarthrosis.1Beck J.J. Bowen R.E. Silva M. What's new in pediatric medial epicondyle fractures?.J Pediatr Orthop. 2018; 38: e202-e206https://doi.org/10.1097/BPO.0000000000000902Crossref PubMed Scopus (30) Google Scholar,3Gottschalk H.P. Eisner E. Hosalkar H.S. Medial epicondyle fractures in the pediatric population.J Am Acad Orthop Surg. 2012; 20: 223-232https://doi.org/10.5435/JAAOS-20-04-223Crossref PubMed Scopus (122) Google Scholar,4Kamath A.F. Cody S.R. Hosalkar H.S. Open reduction of medial epicondyle fractures: operative tips for technical ease.J Child Orthop. 2009; 3: 331-336https://doi.org/10.1007/s11832-009-0185-6Crossref PubMed Scopus (27) Google Scholar,11Pezzutti D. Lin J.S. Singh S. Rowan M. Samora J.B. Pediatric Medial Epicondyle Fracture Management: A Systematic Review.J Pediatr Orthop. 2020; 40: e697-e702https://doi.org/10.1097/BPO.0000000000001532Crossref PubMed Scopus (27) Google Scholar,13Stans AA, Lawrence JTR. Rockwood and Wilkins' Fractures in Children. 8th ed. Philadelphia, PA: Wolters Kluwer; 2015:651-700.Google Scholar However, at present, there is little consensus regarding the indications for surgery, except for fractures with intra-articular incarceration.1Beck J.J. Bowen R.E. Silva M. What's new in pediatric medial epicondyle fractures?.J Pediatr Orthop. 2018; 38: e202-e206https://doi.org/10.1097/BPO.0000000000000902Crossref PubMed Scopus (30) Google Scholar,3Gottschalk H.P. Eisner E. Hosalkar H.S. Medial epicondyle fractures in the pediatric population.J Am Acad Orthop Surg. 2012; 20: 223-232https://doi.org/10.5435/JAAOS-20-04-223Crossref PubMed Scopus (122) Google Scholar,11Pezzutti D. Lin J.S. Singh S. Rowan M. Samora J.B. Pediatric Medial Epicondyle Fracture Management: A Systematic Review.J Pediatr Orthop. 2020; 40: e697-e702https://doi.org/10.1097/BPO.0000000000001532Crossref PubMed Scopus (27) Google Scholar,13Stans AA, Lawrence JTR. Rockwood and Wilkins' Fractures in Children. 8th ed. Philadelphia, PA: Wolters Kluwer; 2015:651-700.Google Scholar Similarly, there is no clear treatment strategy for collateral ligament injuries associated with medial epicondyle fractures. Some reports recommend repair surgery, as residual instability can lead to functional impairment in daily life and sports activities, and ligaments that have healed with conservative treatment can easily fail.5Kim B.S. Park K.H. Song H.S. Park S.Y. Ligamentous repair of acute lateral collateral ligament rupture of the elbow.J Shoulder Elbow Surg. 2013; 22: 1469-1473https://doi.org/10.1016/j.jse.2013.06.018Abstract Full Text Full Text PDF PubMed Scopus (49) Google Scholar,12Shemesh S. Loebenberg M.L. Kosasahvilli Y. Sidon E. Velkes S. Iordache S.D. Posterolateral rotatory instability of the elbow.Harefuah. 2014; 153 (No): 261-265Google Scholar However, some reports have raised the concern that surgery may result in a limited range of motion of the elbow joint.5Kim B.S. Park K.H. Song H.S. Park S.Y. Ligamentous repair of acute lateral collateral ligament rupture of the elbow.J Shoulder Elbow Surg. 2013; 22: 1469-1473https://doi.org/10.1016/j.jse.2013.06.018Abstract Full Text Full Text PDF PubMed Scopus (49) Google Scholar,12Shemesh S. Loebenberg M.L. Kosasahvilli Y. Sidon E. Velkes S. Iordache S.D. Posterolateral rotatory instability of the elbow.Harefuah. 2014; 153 (No): 261-265Google Scholar This patient underwent bilateral ligament repair due to a high degree of elbow joint instability and a desire to return to contact sports. The degree of joint instability caused by ligamentous injuries associated with avulsion and dislocation varies widely, and fluoroscopic assessment of instability, as in this case, is extremely useful in evaluating the pathophysiology and selecting treatment. Elbow instability was evaluated throughout the treatment stages (pre-surgery, post-osteosynthesis, and after ligament repair), allowing for a thorough and balanced treatment approach while confirming the effectiveness of each stage of treatment. We encountered a case of medial epicondyle fracture with MCL and LCL injury. When diagnosing medial epicondyle fractures, it is crucial to consider the possibility of concomitant injury. The evaluation of elbow joint instability using fluoroscopy during surgery proved to be valuable for both understanding the pathology and assessing the effectiveness of treatments.