Natural history of avascular necrosis following traumatic hip dislocation in childhood: a review of 145 cases

Traumatic hip dislocations in a pediatric cohort: The importance of advanced imaging

Purpose

Given that pediatric traumatic hip dislocations are relatively rare, the purpose of the current study is twofold: first, to contribute a significant cohort to the existing corpus, and second, to provide evidence toward the role that computed tomography and magnetic resonance imaging could play in identification and management of this type of injury.

Methods

A retrospective review was conducted of all patients with traumatic hip dislocation who presented from 2012 to 2022 at a tertiary-level pediatric trauma center. Data regarding demographics, mechanism of injury, imaging, and treatment were tabulated. Outcomes of interest included immobilization length, concomitant injuries, imaging performed and findings, and rates of avascular necrosis, pain, and stiffness. Concomitant injuries were identified using imaging, clinical, and operative notes. Differences between categorical variables were compared using chi-square analysis or Fischer-exact testing, while continuous variables were compared using Student t tests or Wilcoxon rank sum tests when appropriate.

Results

Thirty-four patients were identified. Postreduction, 28 patients had a cumulative 17 magnetic resonance imaging, 19 computed tomographies, and 1 intraoperative arthrogram. Of these, 16 patients had 19 injuries identified on advanced imaging that were missed on initial radiographs. Eleven of these patients went on to operative treatment. In eight of these, postreduction advanced imaging helped guide the decision for surgery. In four patients, magnetic resonance imaging was necessary to fully characterize injury to the posterior acetabular rim after initial identification on computed tomography. Magnetic resonance imaging was also used to rule out one computed tomography-diagnosed acetabular fracture.

Conclusion

Magnetic resonance imaging is valuable to fully define associated rim and intra-articular injuries following initial treatment of pediatric traumatic hip dislocations.

Level of evidence

Level IV diagnostic study.

Traumatic hip dislocation in the paediatric population: A case series from a specialist centre

INTRODUCTION

Traumatic hip dislocation is a rare injury in the paediatric population. It can occur after high energy trauma, but also after lower energy injuries especially in younger children. Posterior dislocation is the most common pattern of hip dislocation. In most cases, closed reduction is successful, but occasionally open reduction is required to achieve concentric reduction. The aim of our study was to present the 10-year experience from a Level-1 Trauma Paediatric Hospital and to comment on how our experience correlates with the current literature.

PATIENTS AND METHODS

This is a retrospective case series of all paediatric patients (< 16 years old) with a traumatic hip dislocation presented and/or treated at our institution, between the 1^st of January 2010 and 31^st August 2020.

RESULTS

Thirteen cases of traumatic hip dislocation were identified. There were 7 females. The mean age was 9.8 years. Typically, younger patients were involved in lower energy injuries. The direction of hip dislocation was posterior in ten cases. Associated injuries were seen in eight patients. All cases underwent closed reduction, which was successful in nine cases. Mean time to reduction was 6.8 hours. Post reduction imaging with CT and/or MRI was performed in all cases. There was residual subluxation in three cases, requiring open reduction. In one case with unrecognised undisplaced physeal injury, closed reduction resulted in a Delbet type 1 hip fracture. Two cases developed avascular necrosis (AVN).

CONCLUSIONS

Traumatic paediatric hip dislocation is a rare injury. A target of 6 hours for reduction should be employed as this will reduce the risk of AVN in those who have not permanently damaged the vessels at the time of injury. We advocate all attempts for closed reduction to be performed in an operating theatre with the use of an image intensifier to help identifying associated injuries and confirm concentric reduction. If closed reduction fails, open reduction is required. Post-reduction MRI is an important adjunct to recognise associated soft tissue injuries. Follow up of patients should continue for 2 years as a minimum to help detect AVN.

Management of Neglected Traumatic Hip Dislocation in Children

BACKGROUND

Neglected traumatic hip dislocation in children is uncommon and there is no consensus on appropriate management. Previous studies report varied operative management with high rates of avascular necrosis and postoperative subluxation/dislocation. We report a series of 7 consecutive cases who underwent operative reduction after neglected hip dislocation and describe our technique for treatment.

METHODS

All 7 children sustained posterior dislocations and had no treatment before presentation at our institution. An associated marginal acetabular fracture was present in 2 cases. One additional patient was excluded from the study due to complete loss of articular cartilage that precluded open reduction. The mean time before surgical intervention was 13.1 months (4 to 36 mo) with a mean age of 7 years (5.3 to 10.8 y). All children underwent preoperative skeletal traction for 10 to 14 days. A postero-lateral approach was used in all cases. The acetabulum was cleared of scar tissue and a femoral shortening performed as required (5 cases). Minor erosion of the articular cartilage of the posterior aspect of the femoral head was noted in 3/6 cases. After reduction, a posterior capsulorrhaphy was performed and the patient immobilized in a hip spica for 6 to 12 weeks.

RESULTS

The mean follow-up was 44 months (33 to 56 mo). The majority of children (86%) could walk and run without a limp, could squat, and had no pain. One child had mild pain and a limp. Mean Harris Hip Score was 98.9. No hip subluxed or dislocated postoperatively. The radiographs at latest follow-up showed no evidence of growth disturbance in 29% of cases, coxa magna in 57%, and partial femoral head collapse in 1 case (14%). Of note, those patients managed within 8 months of injury had none or minimal evidence of growth disturbance.

CONCLUSIONS

At medium-term follow-up, open reduction with a postero-lateral approach, posterior capsulorrhaphy, and femoral shortening (as required) produces a satisfactory outcome with a stable, congruent reduction. Good clinical function can be expected with a low incidence of avascular necrosis.

LEVEL OF EVIDENCE

Level IV.

Revascularization of the necrotic femoral head after traumatic open anterior hip dislocation in a child: a case report

INTRODUCTION

Avascular necrosis of the femoral capital epiphysis is the most serious complication after traumatic dislocation of the hip in children. This case report discusses the localization and revascularization of the necrotic femoral head following rarely experienced traumatic open anterior hip dislocation in children.

CASE PRESENTATION

Our patient was an 11-year-old Japanese boy who had open anterior hip dislocation sustained in a traffic accident. Reduction of the hip joint was performed in an emergency operation, and he was evaluated using serial gadolinium-enhanced magnetic resonance imaging. T1-weighted magnetic resonance images showed two bands with low signal intensity in the femoral capital epiphysis on coronal and oblique axial planes, indicating the existence of avascular osteonecrosis of the femoral head. We observed gadolinium enhancement in the central region of the epiphysis, where the area between the two bands with low signal intensity was located. Serial assessment with enhanced magnetic resonance images during a non-weight-bearing period of 1.5 years after injury showed revascularization starting from the central region and converging toward the peripheral region. Although the patient had leg-length discrepancy due to the early epiphyseal closure, non-weight-bearing treatment for the avascular osteonecrosis of the femoral head achieved a favorable outcome without any hip joint dysfunction, pain, or sign of secondary osteoarthritic change within 4.5 years after injury.

CONCLUSION

We confirmed the revascularization process of the necrotic lesion in the femoral capital epiphysis in an 11-year-old boy using serial gadolinium-enhanced magnetic resonance imaging. Conservative non-weight-bearing treatment achieved a favorable outcome.

Open posterior dislocation of hip in a 6-year-old boy: a rare case report

Open hip dislocation in pediatric patients is a rare injury. Open posterior dislocation because of soft tissue damage is unstable after reduction. There is no treatment protocol in the literature for this injury in pediatric patients. We treated a 6-year-old boy presented with open posterior hip dislocation. Thorough debridement was performed and antibiotics were administered to prevent infection, and fixation of reduction with Kirschner-wires (K-wires) was performed. Nonthreaded K-wires were used under an image intensifier to minimize the risk of physeal injury. A hip spica cast was used to prevent the breakage of K-wires into the joint because of movements at the hip.

Emergency department diagnosis and treatment of traumatic hip dislocations in children under the age of 7 years: a 10-year review

BACKGROUND AND AIMS

Traumatic hip dislocations (THD) are uncommon in children. They constitute true emergencies because unrecognised THD leads to avascular necrosis (AVN) of the femoral head. This review presents the evidence for best practice for the diagnosis and treatment of THD in the emergency department (ED) of children under the age of 7 years.

METHODS

Searches for the period 2002-2012 were performed in PubMED, Cochrane database, EMBASE, Google Scholar and hand search.

RESULTS

Twenty-five case reports and case series articles were identified, 53 described children with acute and 23 with neglected THD. Overall, 42 (55%) were male and 73 (96%) sustained a posterior dislocation. Forty-eight (63%) had THD following a low-energy trauma. Eight (11%) reported associated injuries. Twenty-one (39.6%) acute dislocations were reduced in the ED without complications. AVN was identified in 3 (5.7%) children, who underwent reduction ≥10 h after dislocation. Redislocation occurred in 3 (5.7%) children and coxa magna developed in 5 (9.4%). Long-term functional outcome of 42 patients resulted in full recovery, and it was fair to good in 3 (including 2 children with AVN). All neglected cases (≥4 weeks from trauma) needed open reduction in the operating room (OR). AVN was identified in 11 children (47.8%). Hip function was completely recovered in 16 (70%) patients.

CONCLUSIONS

THD in this age group mainly occurs with low-energy trauma and leads to posterior dislocations. Urgent closed reduction of acute cases are done in the OR, or the ED. ED reduction appears to be safe. Neglected THDs need open reduction.

Traumatic hip dislocation in children

The aim of this study was to evaluate the outcomes of reduction in the treatment of traumatic posterior hip dislocation in children. Data of 22 pediatric patients (22 hips) with traumatic hip dislocation from January 1995 to December 2007 were analyzed. The clinical evaluation focused on symptoms, physical findings, and range of motion. Radiographs identified the type of hip dislocation. The hip dislocation classification was based on Thompson and Epstein. The reduction procedure was performed according to three variants: variant 1, closed reduction; variant 2, release of the adductor longus, lengthening of the psoas tendon, and insertion of a Kirschner wire through the femoral head into the acetabulum; and variant 3, removal of the soft-tissue interposition of the hip. After reduction, radiography was used to determine whether the hip is concentric and to check whether any other injuries might have been caused after manipulation. There were six females (27.3%) and 16 males (72.7%) in this study. All had type I posterior dislocation of the hip. The ages of the patients at diagnosis ranged from 3 years, 2 months to 9 years, 10 months. The reduction procedure was performed according to variant 1 in 16, variant 2 in five, and variant 3 in one. We attained excellent results in eight hips (36.4%), good results in seven hips (31.8%), fair results in four hips (18.2%), and poor results in three hips (13.6%). There was avascular necrosis in three hips (13.6%), coxa magna in two hips (9.1%), deficient limb of 2 cm in two hips (9.1%), and a limp in two hips (9.1%). The hip scores were 82.4 points on average (range 62-100). Children with traumatic hip dislocation should undergo reduction as soon as possible. If the interval from injury to reduction exceeds 3 weeks, we suggest that the surgeon release the adductor longus, lengthen the psoas tendon, and insert a Kirschner wire. This simple and safe surgical procedure results in marked improvement in hip function and prevents complications later.

Delayed diagnosis of traumatic hip dislocation mimicking Perthes disease in a child

Traumatic hip dislocations in children are uncommon, yet even trivial injuries may result in dislocation. Avascular necrosis (AVN) occurs in 3-6% of dislocations if reduction is performed within the first 4 h, however, the incidence rises to 66% if the reduction is performed 24 h after dislocation. Awareness and early identification is therefore critical to long term prognosis. The authors report a case of a relatively trivial trauma resulting in hip dislocation in a 5-year-old boy. This case is useful in highlighting that (a) hip dislocation may occur in children with relatively trivial mechanisms, (b) knee pain often indicates an underlying hip pathology and (c) traumatic AVN follows a similar course to Perthes disease and therefore may be management should be tailored in a similar manner to achieve containment within the acetabulum.

Traumatic hip dislocation in childhood

We report the outcome of closed reduction of traumatic hip dislocation in 28 children younger than 16 years of age (average age, 8 years 10 months). At an average follow-up of 8 years and 10 months (range, 2 years - 42 years), 18 patients were asymptomatic and enjoying a normal life, and some of them returned to practice sport activities. The remainder had complications related to associated injuries. There were no cases of avascular necrosis of the femoral head during follow-up. The majority of dislocations were attributable to low energy injuries in children younger than 10 years of age. Traumatic hip dislocation in children is uncommon. Management after reduction is not clearly defined in the literature. It is important to perform reduction as soon as possible to avoid later avascular necrosis.

Traumatic posterior dislocation of the hip in a 3-year-old child

We report the case of a traumatic posterior dislocation of the hip in a 3-year-old boy. After a fall in the garden, the boy was brought to our emergency department where an x-ray confirmed a posterior dislocation of his right hip. A successful prompt reduction was performed in the operating room under general anesthesia. This uncommon injury represents an orthopedic emergency and requires prompt reduction to lessen the risk of complications including avascular necrosis of the femoral head.

Traumatic hip dislocations in children and adolescents: pitfalls and complications

Traumatic hip dislocation is an uncommon injury in children. Lack of familiarity with management of the treating physician may lead to complications. Hip dislocation in young children can occur with minor trauma; in adolescents, greater force is required to produce a traumatic complete hip dislocation. Transient hip dislocation with spontaneous but incomplete reduction is a diagnostic pitfall that can occur in adolescents. Any asymmetric widening of the hip joint warrants additional investigation. Most dislocations in children can be reduced with gentle manipulation. Urgent reduction of the hip within 6 hours of injury reduces the risk of osteonecrosis. However, closed reduction in adolescents should be performed with caution because of the risk of displacement of the femoral head during manipulation. Open reduction is indicated when closed reduction fails or when there is interposition of bone or soft tissue following attempted closed reduction. Late complications include osteonecrosis, coxa magna, and osteoarthritis.

Open reduction for neglected traumatic hip dislocation in children and adolescents

Neglected traumatic dislocation of the hip is extremely rare in children, and the preferred treatment remains unclear. This retrospective case series includes 8 children treated by open reduction. The mean age was 7.5 years (range, 2-16 years), and the mean follow-up was 7 years and 7 months (range, 4 month-16 years). Presenting complaints included pain (5/8) and gait disturbance (8/8). Traction failed to achieve a reduction in all cases. At follow-up, 6 hips remained reduced, and 2 achieved a non concentric reduction. All patients had evidence of avascular necrosis. Two patients, in whom a non concentric reduction was achieved, developed progressive flattening and joint space narrowing. Two patients had mild pain at follow-up, and 6 patients were able to squat. Range of motion was restricted both before and after open reduction, most notably in abduction and rotation. Postoperative improvement was seen in abduction (4 cases). Leg lengths were within 2 cm in 7 of 8 cases, and only 1 patient had a discrepancy greater than 2 cm. The results according to Garrett et al were good in 3, fair in 3, and poor in 2. The mean Harris hip score was 89. Patients with a concentric reduction had an adequate functional outcome despite evidence of avascular necrosis. The prognosis remains guarded, and we expect that a subset of patients will develop premature degenerative joint disease. However, we continue to offer patients an operative reduction, which we feel is preferable to other methods. A failed open reduction does not preclude options for salvage.

Traumatic hip dislocation in a 21-month-old child

Traumatic hip dislocation in the paediatric population is a relatively rare occurrence and constitutes an orthopaedic emergency. A trivial force is all that is required and non-accidental injury should not be necessarily suspected. A case report involving a hip dislocation in a 21-month-old child, the youngest in the recent English literature is detailed.

Ibandronate for prevention of femoral head deformity after ischemic necrosis of the capital femoral epiphysis in immature pigs

BACKGROUND

Femoral head deformity is the most serious sequela of ischemic necrosis of the immature femoral head. The purpose of this study was to determine if a highly potent antiresorptive agent, ibandronate, can inhibit bone resorption during the repair of the infarcted femoral head and thus alter the repair process. We hypothesized that preservation of the trabecular framework by inhibiting osteoclastic bone resorption would minimize the development of deformity in a piglet model of ischemic necrosis. The effect of ibandronate on long-bone growth was also assessed.

METHODS

Ischemic necrosis of the right femoral head was produced in twenty-four piglets by placing a ligature tightly around the femoral neck. The animals were divided into three groups according to whether they received saline solution, prophylactic treatment, or post-ischemia treatment. The contralateral, untreated femoral heads from the animals that had received saline solution served as the normal control group. At eight weeks, the femoral heads were assessed for deformity with radiography and for trabecular bone indices with histomorphometry. Also, the length of femur from the untreated side was measured on the radiographs and compared among the groups.

RESULTS

Radiographic assessment showed that the epiphyseal quotient, determined by dividing the maximum height of the osseous epiphysis by the maximum diameter, was better preserved in the prophylactic (p < 0.001) and post-ischemia (p = 0.02) treatment groups than in the group treated with saline solution. Histomorphometric assessment also showed that the trabecular bone indices were better preserved in the prophylactic and the post-ischemia treatment groups than in the group treated with saline solution (p < 0.01). The mean femoral length on the untreated side of the animals treated with ibandronate was reduced compared with the length on the untreated side of the animals that had received saline solution (p </= 0.01).

CONCLUSIONS

Ibandronate preserves the trabecular structure of the osseous epiphysis and prevents femoral head deformity during the early phase of repair of ischemic necrosis in the piglet model.

Neglected traumatic hip dislocation in children

Traumatic dislocation of the hip in children is a rare injury. We report the outcome of open reduction of neglected traumatic posterior hip dislocation in 18 children. All patients had posterior dislocation and no associated fracture. They presented to the hospital because of persisting pain, deformity, and limp that were present for a mean period of 16 weeks after injury (range, 6-52 weeks). Open reduction was done in all patients because none of the hips could be reduced by skeletal traction in abduction. All of the hips had varying degrees of avascular necrosis (osteonecrosis), with preservation of joint space as seen on radiographs. At short term followup, seventeen children had an excellent functional outcome. We suggest that open reduction is a satisfactory treatment for neglected hip dislocation in children because an anatomically placed femoral head maintains the stimulus for growth of the pelvis and the femur. It prevents deformity and maintains limb length.

Transphyseal fracture-dislocation of the femoral neck: a case report and review of the literature

We describe a case of transphyseal hip fracture-dislocation in a 7.5-year-old patient who was treated initially by open reduction and internal fixation. Soon after the injury, the femoral head developed avascular necrosis. The treatment was focused on maintaining adequate hip range of motion and providing femoral head containment with a combined subtrochanteric femoral osteotomy and shelf acetabuloplasty. The patient's young age and good hip remodeling potential contributed to the favorable clinical outcome 3 years after the injury. The long-term prognosis remains guarded, however.

Traumatic dislocation of the hip in children

In the current study, the incidence, presentation, and treatment of traumatic dislocation of the hip in children will be discussed. The complications and the possible pathologic changes behind the development of avascular necrosis are described. Most children have a good outcome after this injury, perhaps because a concomitant fracture is unusual. The results in children are significantly better than results in adults.

Open reduction of late unreduced traumatic posterior hip dislocation in 12 children

We present 12 children with late unreduced traumatic posterior dislocation of the hip. All had posterior dislocation and no associated fracture. The dislocation had remained unreduced for a mean period of 20 (6-52) weeks. Open reduction was done in all cases, since none of the hips could be reduced with upper tibial skeletal traction in abduction. All the hips showed varying degrees of avascular necrosis, with preservation of joint space on roentgenograms. 11 children had an excellent outcome, according to the criteria of Garrett et al. (1979), after a follow-up of mean 26 (24-36) months. We suggest that open reduction is a satisfactory treatment for hip dislocation of any duration in children.

Avascular necrosis following traumatic hip dislocation in an 8-year-old boy

Avascular necrosis of the femoral head as a complication of a hip location that is caused by minor trauma and is promptly reduced is uncommon in young children. The incidence appears to be from 3% to 6% if reduction is performed within the first 4 h. However, if it does occur, a significant incidence of degenerative joint disease should be anticipated in the patient's later life. As a possible way of surgical treatment, an intertrochanteric and periacetabular osteotomy should be considered to minimise sequelae. Follow-up must be continued until skeletal maturity is reached.

Traumatic hip dislocation in children. Follow up of 13 cases

Thirteen cases of traumatic anterior and posterior hip dislocations in children were treated during a period of 25 years. All of them were available for follow up from 5 to 26 years postinjury. Twelve of the patients had their dislocation reduced within six hours after the injury. None of them developed any complication, and the range of movement was the same as in the noninjured hip. One patient, who had his hip reduced 37 hours after the injury, experienced pain due to osteoarthritis 7 years after the injury at the age of 21 years.