Neglected Traumatic Posterior Dislocation of Hip in Children: Report on 2 cases

Neglected traumatic dislocation of the hip is extremely rare in children and the preferred treatment may still be debatable. In literature definition of old or late dislocation is not clear. According to Garrett et al (1979) that patients who were not treated within 72 hours after injury were called as old unreduced dislocation of hip (1). The option of management of hip dislocation in children are closed and open reduction, subtrochanter osteotomy, arthrodesis, or leave as such and wait for adulthood for total hip replacement (2). Here we present 2 cases of neglected traumatic posterior dislocation management and their outcomes. First came to hospital 10 weeks after trauma, second case came 32 weeks after. First case was treated by closed reduction and percutaneous K-wiring while second was performed adductor tenotomy before open reduction and internal fixation by K wire through the femoral head into acetabulum. Hip spica was applied post operatively. The K wire was removed at 6 weeks. Patients were allowed to bear weight from gradual to full weight bearing after 6 weeks. DISCUSSION: Traumatic hip dislocations are rare in children accounting for less than 5% of all pediatric dislocation (4). Large series has shown this injury 25 times, less common in children than adults (5). It is further rare to see neglected dislocation in pediatric age group. Various studies reported difference methods for management. The options are close and open reduction, sub trochantric osteotomy, arthrodesis, pelvis osteotomy or leave and wait for adulthood (2). According to some studies, close reduction is possible if dislocation is of a relatively short duration (2-4 weeks) (5). Closed reduction and skeletal traction with the limb in abduction has some good results in selected cases (6). Gupta and Shrevet reported good results with the use of heavy traction and sedation (7). Pai and Kumar in their study of eight patients with neglected posterior dislocation concluded that 66% of the patients with dislocation less than 1 year old can be reduced by traction and abduction (3). In our cases, pre-reduction traction had been used temporary with the believe that the traction would stretch the soft tissue that create excessive pressure on the femoral head, making operative intervention easier. Kumar and Jain (8, 9) in their study of 18 patients treated by open reduction after skeletal traction was unsuccessful. Despite varying degree of avascular necrosis, the reported excellent results in 17 patients. In children, traumatic hip dislocation may lead complication such as recurrent dislocation, sciatic nerve palsy, post traumatic degeneration arthritis, coxa magna and avascular necrosis (10, 11). Somehow among all complication, AVN has the worst prognosis (10, 11, 12). AVN usually develops in the first three years (10,11). AVN reaches up to 100% in neglected traumatic hip dislocation patient (13). Growth disturbances develops due to proximal physical damage and effects especially children under the age of 12 and it may lead to leg length discrepancy and angular deformity in femoral neck (14). Growth disturbance usually emerges as coxa magna in children older than 12 years. Coxa magna was also encountered in our case. The resultant coxa magna seen on radiographs here not caused hip symptom years after but predispose hip to secondary osteoarthritis. CONCLUSION: Intra-articular normal saline (IA-NS) injections have been utilized as a placebo in a number of researches pertaining to the management of joints problem such as knee osteoarthritis (OA). It is believed that these IA-NS injections may have a therapeutic effect that has not been quantified in the literature. Lidocaine have some mild anti-inflammatory effect during its relatively short halflife of 1.5 hours. The prompt effect of the local anesthetic providing temporary relief of symptoms can help confirm proper placement of the injection and support that the site injected was the source of the pain. CONCLUSION: Neglected traumatic posterior dislocation of the hip can be treated with closed reduction or open reduction. Repetitive closed reduction trial should be avoided. It should be kept in mind that the rate of avascular necrosis may reach up to 100%.