A juvenile recurrent elbow dislocation resolved by internal fixation of the avulsed lateral chondral fragment after ossification: A case report

Abstract

We report a case of juvenile recurrent posterior dislocation of the elbow with an avulsed cartilage fragment. The avulsed fragment from the lateral condyle gradually became larger since the initial dislocation, and was ossified. After three dislocations, the avulsed bone fragment was secured with screws and the anterior capsule was repaired. Elbow function recovered without any dislocation after the avulsion fracture healed. Open reduction and internal fixation of the avulsed fragment is worth trying at first for juvenile recurrent elbow dislocation, even in chronic cases.

1. Introduction

Recurrent posterior dislocation of the elbow in children is a rare condition. Since nonsurgical management of recurrent posterior dislocation of the elbow is often unsuccessful, various surgical procedures for correcting the specific pathology have been reported.¹ In most cases, ligaments and capsular reconstruction, or some bone procedures, such as bone block or osteotomy of the coronoid process are needed.

We encountered a case of a juvenile girl who suffered three posterior elbow dislocations with an avulsed cartilage fragment. In this report, we describe our unusual case and discuss the pathophysiology and surgical results for this type of injury.

1.1. Case report

An 8-year-old girl fell while skating and was referred to a local clinic for examination of her left elbow. Radiographs revealed posterior dislocation of the left elbow (Fig. 1). There was a small avulsed fragment just proximal to the proximal radial epiphysis; however, this was not noticed. Under intravenous sedation, the elbow was reduced, and an elastic bandage was applied for two weeks. Seven months after the initial injury, she fell, sustained a left elbow dislocation, and was referred to the local clinic again. Radiographs and computerized tomography (CT) revealed an avulsion fracture of the lateral condyle of the humerus (Fig. 2). The elbow dislocation was reduced under non-anesthesia, and the elbow was immobilized in a splint for two weeks. After that, symptoms, such as pain, popping, or instability of the left elbow joint were not observed. Seven months after the second injury, she fell and sustained a posterior dislocation for the third time, and was referred to our clinic. CT revealed that an avulsed bone fragment from the lateral condyle became larger compared to that at the time of the second injury (Fig. 3A–C). Under general anesthesia, the elbow was reduced, and stress radiographs showed varus instability and posterolateral rotatory instability (PLRI), which was confirmed by a positive PLRI test. However, magnetic resonance imaging did not reveal any injury of the lateral ligaments of the elbow. Surgery was performed to secure the fragment of the lateral collateral ligament (LCL) attachment using the Kocher approach.

Fig. 1.

Anteroposterior and lateral radiographs of the left elbow at the time of the first posterior dislocation. There was a small avulsed fragment just proximal to the proximal radial epiphysis.

Fig. 2.

Lateral radiograph and three-dimensional computerized tomography (CT) at the time of the second elbow dislocation. An avulsion fracture of the lateral condyle was observed.

Fig. 3.

Anteroposterior and lateral radiographs (A, B) and three-dimensional CT (C) at the time of the third elbow dislocation. An avulsed bony fragment became larger compared to that at the time of the second dislocation.

During surgery, the LCL connected to the fragment was intact, but a part of the anterior capsule was torn. The fragment was reduced accurately to the lateral condyle and was secured with two 3.0-mm cannulated cancellous screws (Fig. 4). The torn part of the anterior capsule was repaired. After immobilization in a long arm splint for four weeks, active motion exercises of the elbow were initiated. Four months after the surgery, the screws were removed and the patient had a negative PLRI test under general anesthesia. One year after the internal fixation, the range of motion of the left elbow recovered compared to that of the contralateral side (extension, 10°; flexion, 140°). The patient and her families were informed that data from the case would be submitted for publication, and gave their consent.

Fig. 4.

Anteroposterior and lateral radiographs after the operation. The fragment was reduced accurately and was secured with two 3.0-mm cannulated cancellous screws.

2. Discussion

The pathology of recurrent posterior dislocation of the elbow in children involves any or all combinations of collateral ligament instability, capsular laxity, bone and articular cartilage defect, and shallow trochlear notch.¹ In the present case, an avulsed fragment of the LCL attachment caused recurrent dislocation. Although the avulsed fragment was extremely small and could not be noticed during the initial injury, the fragment was clearly observed on radiographs at the second dislocation. Supposedly, the avulsed cartilage fragment at the initial dislocation gradually became larger, bony, and finally visible under X-ray. Blood supply from the LCL and the prolonged course certainly contributed to this phenomenon.

It was reported that an avulsed cartilaginous fragment of the LCL attachment could rarely cause recurrent elbow dislocation in children.² In the present case, the lack of immobilization and evaluation after primary dislocation could cause recurrent dislocation. Posterior splint immobilization for three weeks is frequently preferred.¹ However, some authors have reported good clinical outcomes of early active motion.³ Stability of the elbow to valgus stress, with the forearm pronated after reduction of the posterior dislocation indicated that early motion could be permitted because the anterior portion of the medial collateral ligament was intact.⁴ In the present case, the initial elbow dislocation was reduced under anesthesia, but no elbow instability test was performed. The second reduction was performed under non-anesthesia. Any examination of elbow instability in children is generally unacceptable due to complaints of pain or redislocation.⁵ Above all in children, it may be necessary to reduce the elbow dislocation and examine the instability under anesthesia for a detailed diagnosis and appropriate treatment strategy.

Various surgical procedures for recurrent posterior dislocation of the elbow in children have been reported.¹ In past reports, most cases needed ligaments and capsular reconstruction or some osteoplasty procedures.^1,6 However, we performed osteosynthesis of an avulsed fragment of the LCL attachment as well as anterior capsule repair, and successfully reestablished sufficient stability to prevent recurrence of the dislocation without any supplemental ligament reconstruction. In this case, although the avulsed fragment was pulled back to the original bone bed, the impossibility of repositioning the fragment because of the contracture or attenuation of the LCL was of concern. In addition, ligament thickening or scarring could be one of the causes of post-traumatic elbow contracture⁷; in contrast, the mechanism underlying the elasticity of the ligament attached to the avulsed fragment in chronic cases is uncertain. Su et al. reported eight cases of chronic ulnar collateral ligament humeral origin avulsion fracture in young baseball players.⁸ In that report, no ulnar collateral ligament shortening was encountered and the avulsed fragment could be repositioned in all cases. In addition, there were no cases of ligament shortening in previous reports of chronic avulsion fracture of the anterior cruciate ligament of the knee in adolescents.^9,10 Open reduction and internal fixation of the LCL avulsion fracture is also worth trying at first for juvenile recurrent elbow dislocation, even in chronic cases.

Funding sources

None.

Declaration of competing interest

None.