Traumatic hip dislocation in childhood

Clinical treatment of traumatic hip dislocation in children: a single-centre retrospective study

This study aimed to analyse the treatment and outcomes of traumatic hip dislocation (THD) in children. Clinical data of children with THD were collected at our clinical centre from 1 June 2012 to 1 January 2023. Demographic data, injury mechanism, type of dislocation, combined injuries, reduction time, reduction method, and radiographs were analysed. The Merle d'Aubigné-Postel hip score was used to evaluate hip function and complications at the final follow-up. A total of 19 children with THD were enrolled, including 12 male and seven female patients, with an average age of 8.28 ± 0.99 years. Posterior dislocation was the main type of dislocation (89.47%). Fifteen patients (78.95%) had experienced high-energy injuries and traffic accidents were the main causes of injury (47.37%). Closed reduction was performed as soon as possible, and open reduction was performed if necessary. The hip scores of 18 patients (94.74%) were excellent. One patient had osteonecrosis of the femoral head, with a hip function score of 10 (moderate). High-energy injuries, such as traffic accidents, have gradually become the main cause of injury. The prognosis for THD in children is generally good.

Traumatic Hip Dislocation: Pediatric and Adult Evaluation and Management

Traumatic hip dislocation of a native hip joint represents an orthopaedic emergency that should be treated promptly. Dislocations can be classified based on the associated injuries and the direction of dislocation. Expeditious evaluation, reduction, and management of associated injuries are required to optimize short and long-term function of the hip. There are several important differences between the blood supply and ossification of the pediatric hip that necessitate different strategies for the evaluation and management of traumatic hip dislocations in pediatric patients. Appropriate treatment is dictated by the direction and type of dislocation as well as associated injuries. In addition to closed reduction, arthroscopy, open reduction (potentially with fracture fixation and/or soft-tissue repair), osteotomy, and total hip arthroplasty all have roles in treatment. Consensus on optimal postreduction activity protocols after simple hip dislocation remain unestablished. Short and long-term outcomes are largely driven by the amount of time from injury to reduction and associated injuries.

Acetabular "Fleck" Sign: Outcomes of Surgical Repair

BACKGROUND

Traumatic, posterior hip dislocations in the pediatric population are typically managed by closed reduction to achieve a concentric hip joint. The presence of an acetabular "fleck" sign, despite concentric reduction, has been shown to signify significant hip pathology. The purpose of this study was to evaluate the outcomes of open labral repair through a surgical hip dislocation (SHD) in a consecutive series of patients with an acetabular "fleck" sign associated with a traumatic hip dislocation/subluxation.

METHODS

A retrospective review of patients between 2008 and 2022 who presented to a single, level 1 pediatric trauma center with a traumatic posterior hip dislocation/subluxation was performed. Patients were included if they had an acetabular "fleck" sign on advanced imaging and underwent open labral repair through SHD. Medical records were reviewed for sex, age, laterality, mechanism of injury (MOI), and associated orthopaedic injuries. The modified Harris hip score (mHHS) was utilized as the primary clinical outcomes measure. Patients were assessed for the presence of heterotopic ossification (HO) and complications, including implant issues, infection, avascular necrosis (AVN), and post-traumatic dysplasia.

RESULTS

Twenty-nine patients (23 male, average age: 13.0±2.7 y; range: 5.2 to 17.3) were identified. Eighteen injuries were sports related, 9 caused by motor vehicle accidents, and 1 pedestrian struck. All patients were found to have an acetabular "fleck" sign on CT (26 patients) or MRI (5 patients). Associated injuries included: femoral head fracture (n=6), pelvic ring injury (n=3), ipsilateral femur fracture (n=2), and ipsilateral PCL avulsion (n=1). At the latest follow-up (2.2±1.4 y), all patients had returned to preinjury activity/sport. Three patients developed asymptomatic, grade 1 HO in the greater trochanter region. There was no incidence of AVN. One patient developed post-traumatic acetabular dysplasia due to early triradiate closure. mHHS scores showed excellent outcomes (n=21, 94.9±7.4, range: 81 to 100.1).

CONCLUSIONS

The acetabular "fleck" sign indicates a consistent pattern of osteochondral avulsion of the posterior/superior labrum. Restoring native hip anatomy and stability is likely to improve outcomes. SHD with open labral repair in these patients produces excellent clinical outcomes, with no reported cases of AVN.

LEVEL OF EVIDENCE

Level IV-therapeutic.

Clinical Outcomes and Associated Pathologies Following Pediatric Traumatic Hip Dislocations: A Systematic Review of the Literature

INTRODUCTION

Pediatric traumatic hip dislocations are a rare condition that can have devastating short and/or long-term outcomes and associated pathologies (APs), including associated injuries (AIs) and long-term adverse events (LTAEs), with negative long-term sequelae. Currently, there are little data that exist on the rate of APs, with the most notable being avascular necrosis (AVN), for pediatric traumatic hip dislocations. The purpose of this systematic review is to evaluate the outcome relative frequency of dislocation direction, reduction type, and rate of APs for traumatic hip dislocations in the pediatric population.

METHODS

A systematic review on the topic of traumatic hip dislocations in the pediatric population was performed using PubMed, ScienceDirect, Web of Science, CINAHL, and MEDLINE databases from database inception to March 30, 2023. Inclusion criteria was full-text English articles, addressed traumatic hip dislocations, and pediatric patients (<18 y old).

RESULTS

A total of 24 articles (n=575 patients) met final inclusion criteria from a total of 219 articles retrieved from the initial search. For the average age of the included patients with reported age (n=433 patients), the frequency weighted mean was 9.50 years±1.75 years with a frequency weighted mean follow-up time of 74.05 months ±45.97 months (n=399 patients). The most common dislocation direction was posterior (86.4%), the most common treatment type was closed reduction (84.5%), AVN was the most common type of LTAEs (15.5% of APs), and labral/capsular injuries and acetabular fractures were the most common type of AIs (14.0% and 9.4% of APs, respectively). There were a combined total of 414 APs (72%) out of 575 total patients.

CONCLUSION

Pediatric traumatic hip dislocations are associated with a high rate of AIs and LTAEs (72%, 414 APs out of 575 patients). AVN, labral/capsular injuries, and acetabular fractures are the most common APs after pediatric traumatic hip dislocations. Pediatric hip dislocations are usually posterior and commonly managed through closed reduction.

LEVEL OF EVIDENCE

III, Systematic Review.

Epidemiology and injury morphology of traumatic hip dislocations in children and adolescents in Germany: a multi-centre study

OBJECTIVE

Traumatic hip dislocations are very rare in childhood and adolescence. The aim of this multi-centre study is to analyse the current epidemiology and injury morphology of a large number of traumatic hip dislocations in children. This can provide a better understanding of childhood hip dislocations and contribute to the development of a therapeutic approach in order to prevent long-term impacts.

METHODOLOGY

This retrospective, anonymised multi-centre study included patients, aged up to 17 years, with acute traumatic hip dislocations and open growth plates. The patients came from 16 German hospitals. Exclusion criteria included insufficient data, a positive history of hip dysplasia, or an association with syndromal, neurological or connective tissue diseases predisposing to hip dislocation. An analysis was carried out on the patients' anthropometric data and scans (X-ray, MRI, CT), which were collected between 1979 and 2021. Gender, age at the time of dislocation, associated fractures, mechanism of injury, initial treatment including time between dislocation and reduction, method of reduction, treatment algorithm following reduction and all documented complications and concomitant injuries were evaluated.

RESULTS

Seventy-six patients met the inclusion criteria. There were two age peaks at 4-8 years and 11-15 years. There was an increased incidence of girls in the under-eight age group, who had mild trauma, and in the group of over-eights there were more boys, who had moderate and severe trauma. Dorsal dislocation occurred in 89.9% of cases. Mono-injuries dominated across all age groups. Concomitant injuries rarely occurred before the age of eight; however, they increased with increasing ossification of the acetabulum and appeared as avulsion injuries in 32% of 11-15-year-olds. Of the 76 patients, 4 underwent a spontaneous, 67 a closed and 5 a primary open reduction. A reduction was performed within 6 h on 84% of the children; however, in around 10% of cases a reduction was not performed until after 24 h. Concomitant injuries needing intervention were identified in 34 children following reduction. Complications included nerve irritation in the form of sensitivity disorders (n = 6) as well as avascular necrosis (AVN) of the femoral head in 15.8% of the patients (n = 12).

CONCLUSIONS

Traumatic hip dislocations are rare in childhood and adolescence and have high complication rates. The most severe complication, femoral head necrosis, occurred in 16% of cases. Minor injuries, especially in younger children, are enough to cause a dislocation. Posterior dislocation was more frequent and primarily occurred as a mono-injury; however, concomitant injuries must be considered with increasing age. Children continue to experience delayed reductions. The length of time until reduction, age and the severity of the concomitant injury play a role in the development of femoral head necrosis; however, this topic requires additional investigation.

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 Obturator Hip Dislocation in a 9-Year-Old Girl: A Case Report

CASE

We present a case of traumatic anterior obturator hip dislocation in a pediatric patient with a focus on acute management of this injury. The orthopaedic team successfully performed closed reduction of this injury on an emergent basis, and the patient had minimal issues with ambulation and pain at subsequent follow-up.

CONCLUSION

Pediatric traumatic hip dislocations are rare injuries with potentially devastating sequelae, particularly if diagnosis and treatment are delayed. Proper technique during closed reduction is essential. Be prepared for potential emergent open reduction. Two years of postinjury follow-up is recommended to monitor for signs of femoral head osteonecrosis.

Traumatic Hip Dislocation in Pediatric Patients: Clinical Case Series and a Narrative Review of the Literature with an Emphasis on Primary and Long-Term Complications

Traumatic hip dislocation is a rare injury in pediatric populations. Dislocation may be associated with low-energy trauma, such as a minor fall. Traumatic hip dislocation is associated with severe complications, such as avascular necrosis of the femoral head. Timely diagnosis and reposition decrease the rate of complications. In this study we retrospectively assessed traumatic hip dislocations in pediatric patients during a 10-year timespan in a university hospital. There were eight cases of traumatic hip dislocations. All patients had a minimum follow-up of two years and were followed with MRI scans. One patient developed avascular necrosis during the follow-up which resolved conservatively. There were no other significant complications. In conclusion, traumatic hip dislocation is a rare injury which is associated with severe complications. Patients in our case series underwent a timely reposition. The complication rate was similar to previous reports.

The Not-So-Merry-Go-Round: Traumatic Inferior-Anterior Hip Dislocation in a 9-Year-Old

Merry-go-rounds are not as innocuous as they may seem. Pediatric hip anterior-inferior dislocations are very rare and can be associated with low-energy trauma. Prompt recognition of pediatric hip dislocations is vital, and this should be treated as a time-sensitive orthopedic emergency. Closed reduction within 6 hours minimizes the risk of avascular necrosis (AVN). We present a case of a 9-year-old boy with an inferior-anterior hip dislocation following low energy trauma while playing on a merry-go-round. The patient was emergently brought to the theatre for closed reduction under general anesthesia within 6 hours. At his 12-month follow-up, he has a full range of motion without any pain.

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.

Surgical treatment of a traumatic open anterior hip dislocation in a child: A case report and review of 13 cases in the literature

Due to the high probability of infection and avascular necrosis, traumatic open anterior hip dislocation poses a serious orthopedic emergency. Despite the emergency of the issue, it appears to be an under-researched topic in the literature. In this study, we present open anterior hip dislocation with both trochanteric fractures in a child and review other pediatric cases from the literature. Because of rareness, there is no standard surgical and postoperative treatment algorithm. We discussed the mechanism of injury, wound size, time of the reduction, associated injury, type of treatment, type of immobilization, clinical and functional results to present a collective perspective on the literature. Once we have compared all of these situations, dealing with infection is key to satisfactory clinical and functional outcomes. The early reduction was the most important point in both coping with infection and preserving avascular necrosis of the femoral head.

MRI Is Better Than CT Scan for Detection of Structural Pathologies After Traumatic Posterior Hip Dislocations in Children and Adolescents

BACKGROUND

Traumatic posterior hip dislocations in children and adolescents requires emergent closed reduction. Postreduction imaging is necessary to assess the concentricity of reduction and structural injuries to the hip. There is no a consensus for which imaging is a modality of choice in such condition. The purposes of this study are to describe magnetic resonance imaging (MRI) findings of traumatic posterior hip dislocations and to compare the effectiveness of MRI with computerized tomography (CT) in detecting structural abnormalities of the hip that impact patient management.

METHODS

This study is a retrospective review of imaging in traumatically dislocated hips in patients who were treated at our institution. All CT and MRI imaging were reviewed and specific osseous and soft tissue injuries documented by consensus among 2 musculoskeletal pediatric radiologists who interpreted the MRI and CT scans of each patient in a blinded manner.

RESULTS

In total, 27 patients (23 males, 4 females) with mean age of 12.5 years (range, 2 to 19 y) with postreduction MRI were evaluated. MRI findings revealed femoral head injuries in 17 (62.9%), posterior labral entrapments in 6 (22.2%), posterior labral tears in 17 (62.9%), posterior wall fractures in 15 (55.5%), fracture of the posterior unossified part of acetabulum in 4 (14.8%), and ligamentum teres injuries in 8 (29.6%). Of 16 patients who had postreduction CT scans, 6 (37.5%) had femoral head fractures, 9 (56.3%) had posterior wall fractures, and 8 (50%) had intra-articular osseous entrapments. All bony fractures and intra-articular entrapment could be seen on MRI imaging. In 16 patients with both CT and MRI, posterior acetabular injury was detected in 10/16 (62.5%) on MRI and 9/16 (56.3%) on CT. Three patients with entrapment of labrums identified on MRI could not be seen on CT scan. One patient with persistently unstable hip after reduction had an entrapped unossified portion of acetabular fracture which was seen on MRI but not on CT.

CONCLUSIONS

MRI is superior to CT scan for detection of structural injuries in children and adolescents with traumatic hip dislocation. The unique structural injuries included entrapment of posterior labrum and posterior unossified acetabular fractures could be seen only at MRI. These findings will impact surgical decision making of these injuries.

LEVEL OF EVIDENCE

Level IV.

Ipsilateral open anterior hip dislocation and avulsion fracture of the greater trochanter: An unusual case report

Approximately 3% of all joint dislocations involve the hip joint, and only 8-10% of these will be anterior. Traumatic anterior open dislocation of the hip is rare in children and prone to be associated with injuries, extensive soft tissue damage, and avascular necrosis of the femoral head. We present a case of a 13-year-old boy who had an open anterior dislocation of the hip with ipsilateral avulsion of the greater trochanter after a tractor wheel crush in an agricultural accident. Additional lesions included a diaphyseal closed fracture of the contralateral femur. We report this case because of the rarity and seriousness of this injury due to its progressive complications and difficulties related to its management.

Traumatic Obturator Hip Dislocation with Marginal Femoral Head Fracture in a 15-Year-Old Adolescent: A High-Energy Trauma-A Case Report and a Review of the Literature

We report the case of a 15-year-old boy brought to the emergency department after a bike accident, complaining of an isolated left hip pain. The X-rays showed an obturator hip dislocation treated by closed reduction under general anaesthesia, followed by 6 weeks of discharge. The follow-up MRI performed 6 weeks after the trauma showed an avascular femoral head necrosis, for which we performed multiple retrograde femoral head drilling, completed by the injection of autologue stem cells from the iliaq crest. One year later, the patient has no hip pain, no joint limitation, and can practice BMX at a high level again. The purpose of this report is to make the physicians aware of this rare problem that may be damaging for hip function, especially in young people.

Closed reduction of a traumatic hip dislocation in children: case report

Traumatic dislocation of the hip in children is a rare disease. It only represents 5% of hip dislocations in all age groups. Before 10 years, the mechanism is often a minimal domestic accident; after 10 years, the dislocation occurs with the waning of an accident of the public highway. It is different from that of the adult by its rarity, its ease of reduction and better prognosis. This is an emergency trauma: risk necrosis of the femoral head (If delayed reduction). We report a rare case of a 3 year old boy, who suffered from bipolar trauma after a fall near his height of his house causing him a detachment of the right humerus and post-traumatic dislocation of the left hip. The diagnosis was clinically confirmed by the results of standard radiographs and CT scans of the pelvis. The consultation period to emergencies was 5 hours after the trauma. We performed an hour after a closed reduction under general anesthesia for hip dislocation with establishment of a splint pelvic-pedal for analgesic keep for three weeks. The radiological outcome was satisfactory. Peeling Salter I humerus was reduced by orthopedic manner and immobilized by thoracoabdominal plaster to keep for a month. The child was discharged the next day. Reviewed in consultation after a month, the clinical examination showed a steady left hip. Traumatic dislocation of the hip in children is a rare diagnosis, the management should as urgent as possible to overcome the different possible subsequent complications dominated by coxa magna.

Surgical Hip Dislocation for the Treatment of Intra-Articular Injuries and Hip Instability Following Traumatic Posterior Dislocation in Children and Adolescents

BACKGROUND

Traumatic posterior hip dislocation in children is a rare injury that typically is treated with closed reduction. Surgical treatment is typically recommended for nonconcentric reduction with joint space asymmetry with entrapped labrum or an osteochondral fragment. The surgical hip dislocation (SHD) approach allows for full assessment of the acetabulum and femoral head and has been our preferred surgical strategy. The purpose of this study was to (1) describe the intra-articular pathologic findings seen at the time of SHD; and (2) to investigate hip pain, function, and activity level of a cohort of children and adolescents after open treatment of a posterior hip dislocation using the SHD approach.

METHODS

Following IRB approval, 23 patients who sustained a traumatic posterior hip dislocation between January 2009 and December 2013 were identified. In 8/23 (34.8%) patients there was evidence of nonconcentric reduction after closed treatment and surgical treatment was performed using the SHD approach. Seven male and 1 female (mean age, 11.2 y; range, 6 to 14.6 y) were followed for an average of 28 months (range, 13 to 67 mo). The modified Harris Hip Score (mHHS) and the University of California Los Angeles activity score assessed clinical hip outcome and activity level at minimum of 1 year after surgery.

RESULTS

Six patients were treated after an acute trauma, whereas 2 were treated after recurrent dislocations. Five patients were involved in motor vehicle accidents and 3 in sports-related injuries. Intraoperative findings include posterior labral avulsion in all patients, fracture of the cartilaginous posterior wall (n=3), and femoral head chondral injuries (n=5) and fracture (n=1). The labral root was repaired using suture anchor technique in 7/8 patients and resected in 1. In 2 patients, labral repair was complemented by screw fixation of the posterior wall. All but one patient (mHHS=94) reported maximum mHHS. The University of California Los Angeles activity score was 10 for 5/8 patients and 7 in 3 patients. No case of femoral head osteonecrosis was noted. One patient developed an asymptomatic heterotopic ossification.

CONCLUSIONS

When open reduction is recommended for the treatment of intra-articular pathologies and hip instability following traumatic dislocation of the hip in children and adolescents, the SHD is an excellent approach that allows surgical correction of the damaged bony and soft-tissue structures including repair of the capsule-labral complex, and reduction and internal fixation of the cartilaginous posterior wall and femoral head fractures.

LEVEL OF EVIDENCE

Level IV.

Adolescent Hip Dislocation Combined With Proximal Femoral Physeal Fractures and Epiphysiolysis

BACKGROUND

The risks and long-term effects of acute hip dislocation combined with proximal femoral physeal fractures and epiphysiolysis have been minimally addressed in the literature. This infrequent combination must be understood to avoid the major complications of complete separation of proximal femoral components during attempted reduction and to predict the probable outcome of surgical treatment.

METHODS

Medical records and imaging were retrospectively reviewed to identify patients with a diagnosis of severe to complete slipped capital femoral epiphysis (CFE) or proximal femoral epiphysiolysis in association with hip dislocation. The focus included possible anatomic/vascular disruption and their consequences.

RESULTS

Twelve patients were identified. Nine dislocations were posterior; 3 were anterior. In 4 patients, the intact proximal femur was dislocated posteriorly. In 3 patients only the femoral neck was reduced, whereas the CFE remained dislocated. In 1 patient percutaneous pinning was done in the dislocated position before closed reduction. The reduction was successful. In 7 patients only the CFE (4 patients) or femoral neck (3 patients) was displaced at the initial presentation in the emergency room. One patient presented with posterior dislocation associated with complete separation of both components. Ten patients underwent open reduction and internal fixation. Two patients had closed reduction. Nine patients developed complete avascular necrosis, progressive collapse of the femoral head, and degenerative arthritis. Three subsequently had a total hip arthroplasty. One patient developed ischemic change limited to the femoral neck and a nonunion through the epiphysis. One patient had incomplete ischemic necrosis. Only 1 patient had no evidence of ischemic necrosis.

CONCLUSIONS

This combination of injuries has several anatomic variations. Leaving the CFE dislocated while reducing only the femoral neck must be avoided. Reduction should be done in the operating room with muscle relaxation. The emergency room is not the venue for reduction. The risk of avascular necrosis is extremely high, whether the separation occurs during the acute dislocation or attempted reduction.

LEVEL OF EVIDENCE

Level IV-case series (retrospective review).

[Traumatic hip dislocation in a 6-year-old male child: Seldom but demanding]

Traumatic hip dislocations in children are not frequent but constitute true emergencies. They require urgent reduction because of the risk of consecutive avascular necrosis of the femoral head. We report a 6-year-old boy with traumatic posterior hip dislocation on a vacation abroad. After closed reduction the day of the accident, a hip spica cast was applied and the patient was transferred home. Once home, X‑ray and CT diagnostics were completed by MRI. In future, long-term clinical and radiological investigations for avascular necrosis and growth disorders, as well as thoroughly informing the parents, should be mandatory.

Traumatic, Posterior Pediatric Hip Dislocations With Associated Posterior Labrum Osteochondral Avulsion: Recognizing the Acetabular "Fleck" Sign

BACKGROUND

Traumatic dislocation of the hip is uncommon in the pediatric population. Concentric reduction is usually achieved by closed means. Open reduction may be needed if there is femoral head fracture, incarcerated fragment, or incomplete reduction due to soft tissue entrapment. We present a series of 10 patients who sustained a posterior hip dislocation or subluxation with associated osteochondral avulsion of the posterior labrum. During surgery they were noted to have a labral injury pattern not previously recognized. Such treatment was dictated by postreduction advanced imaging, which revealed a consistent acetabular "fleck" sign indicative of this labral injury, which has not been previously described in literature.

METHODS

We performed a retrospective case review of patients with traumatic posterior hip dislocation/subluxation, treated operatively for a suspected associated labral tear and fractures.

RESULTS

Ten patients (2 girls and 8 boys) were identified. Average age was 12.7 years. Eight patients had postreduction computed tomography scans, which revealed a posterior acetabular wall "fleck" sign, suggestive of osteochondral injury. The small bony fragment was consistently displaced at least 2 to 3 mm in all patients with majority of the posterior wall remaining intact. Closed reduction was felt to be congruent in 7 of the 10 patients. All patients were treated operatively for exploration and stabilization of the suspected posterior labrum pathology and associated injuries using a surgical hip dislocation. A consistent pattern of labral pathology was seen in all patients, with disruption of the posterior labrum from the superior 12 o'clock attachment to detachment at the inferior 6 o'clock location. Reattachment of the osteochondral labral avulsion was performed with suture anchors along the posterior rim, and the associated femoral head fractures were also addressed with internal fixation. Two patients had inadequate follow-up and were excluded, the average follow-up for the remaining 8 patients was 9.8 months (range, 6 to 26 mo). There were no findings of avascular necrosis in any of the 8 patients.

CONCLUSIONS

Posterior hip dislocation in children may produce an acetabular "fleck" sign on advanced imaging, which in a stable, concentrically reduced hip has been treated without surgery in the past. Acetabular fleck sign may represent a near-complete avulsion of the posterior labrum as seen in our series. We recommend a high suspicion for this type of labral pathology and surgical repair when acetabular "fleck" sign is identified with hip subluxation or dislocation. Traumatic, posterior hip dislocations in young patients may be associated with significant labral pathology. Acetabular "fleck" sign on advanced imaging may predict such pathology.

LEVEL OF EVIDENCE

IV, retrospective study.

Femoroacetabular Impingement Is Associated With Sports-Related Posterior Hip Instability in Adolescents: A Matched-Cohort Study

BACKGROUND

Femoroacetabular impingement (FAI) deformity has been associated with posterior hip instability in adult athletes.

PURPOSE

To determine if FAI deformity is associated with posterior hip instability in adolescents, the femoral head-neck junction or acetabular structure in a cohort of adolescent patients who sustained a low-energy, sports-related posterior hip dislocation was compared with that in a group of healthy age- and sex-matched controls with no history of hip injury or pain.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

We identified 12 male patients (mean age, 13.9 years; range, 12-16 years) who sustained a sports-related posterior hip dislocation and underwent a computed tomography (CT) scan after closed reduction. For each patient, 3 age- and sex-matched healthy controls were identified. Femoral head-neck type was assessed by measurement of the alpha angle on the radially oriented CT images at the 12-, 1-, 2-, and 3-o'clock positions. Age, body mass index (BMI), alpha angle at each position, acetabular version, Tönnis angle, and lateral center-edge angle (LCEA) on the involved hip in the dislocation group were compared with those of the matched controls using a mixed-effects model. A logistic regression analysis using a generalized estimating equation was used to compare the percentage of subjects with cam-type FAI deformity (alpha angle >55°) in each group.

RESULTS

The dislocation and control groups were similar in age distribution and BMI (P > .05). The mean alpha angles were statistically significantly higher in the dislocation group compared with the control group at the superior (46.3° ± 1.1° vs 42.7° ± 0.6°; P = .0213), superior-anterior (55.5° ± 1.9° vs 46.0° ± 1.3°; P = .0005), and anterior-superior (54.9° ± 1.5° vs 48.9° ± 1.0°; P = .0045) regions. Cam deformity was present in a larger proportion of patients in the dislocation group than in the control group (P < .0035). An alpha angle greater than 55° was present in 16.7% of the dislocation group and 0% of the control group at the 12-o'clock position (P = .1213), 41.7% versus 0% at the 1-o'clock position (P = .0034), 58% versus 6% at the 2-o'clock position (P = .0004), and 25% versus 2.8% at the 3-o'clock position (P = .0929). Acetabular anteversion was lower in the dislocation group (9.6° ± 1.4°) compared with the control group (15.1° ± 0.8°) (P = .0068). Mean acetabular LCEA was within a normal range in both groups.

CONCLUSION

A significantly higher mean alpha angle from the superior to the anterior-superior regions of the femoral head-neck junction and lower acetabular version were found in adolescents who sustained low-energy, sports-related posterior hip dislocations.

Missed adolescent acetabular apophyseal avulsion with late hip dislocation

BACKGROUND

Chronic hip dislocation associated with acetabular apophyseal avulsion in adolescence is rare. Whilst superior acetabular rim fractures have a documented theoretical risk of hip instability, we have not found a case of chronic dislocation resulting from this.

METHODS

We report a case of a 12-year-old healthy boy who initially sustained a missed right acetabular apophyseal avulsion after falling from a quad bike. This was missed on the initial radiograph and a subsequent radiograph following weight bearing a few days later showed a hip dislocation that was also missed. Upon diagnosis at 6 weeks, he underwent open reduction but also required acetabuloplasty to stabilise the hip.

RESULTS

At 2 years follow-up, he was enjoying pain free swimming, cycling and walking. His Harris hip score was 87.

CONCLUSION

This case reinforces the need for recognition that in the patient presenting with knee or thigh pain, exclusion of hip pathology is required. It also explores the pitfalls of diagnosis associated with rare patterns of injury and the need for adequate investigations such as examination under anaesthetic, arthrography and MRI. The use of acetabuloplasty is shown to be a useful strategy for the unstable hip resulting from irreparable acetabular rim fracture.

Surgical Hip Dislocation is Safe and Effective Following Acute Traumatic Hip Instability in the Adolescent

BACKGROUND

A traumatic hip dislocation in the pediatric patient is a rare but potentially catastrophic injury. The purpose of this study was to review our early clinical results and radiographic morphology of hips treated with a surgical hip dislocation (SHD) approach for intra-articular hip pathology resulting from traumatic instability in pediatric and adolescent patients.

METHODS

This is a retrospective analysis of a consecutive series of patients presenting with nonconcentric reduction after traumatic hip instability. All patients were treated with a transtrochanteric SHD with concomitant procedures based on intra-articular findings. Radiographic evaluations and Harris Hip Scores were completed at final follow-up.

RESULTS

Eleven male patients, mean age of 12.3 years (range, 9.3 to 16.1 y) and mean body mass index 19.6 kg/m (range, 15.4 to 28.0 kg/m). Intraoperative findings included: labral tear (8), femoral cartilage injury (5), acetabular rim fracture (4), acetabular cartilage delamination (3), loose body (2), and femoral head osteochondral fracture (1). Postoperatively, 1 patient developed a transient peroneal nerve palsy. At a mean 24.5 months (range, 12.0 to 48.1 mo) postoperatively, no hips have radiographic evidence of osteonecrosis. The mean lateral center edge angle was 20 degrees (range, 9 to 38 degrees) with 6 hips of <20 degrees; mean acetabular index 9 degrees (range, -2 to 23 degrees) with 5 hips of >10 degrees; mean α-angle 56 degrees (range, 48 to 62 degrees) with 6 hips of >55 degrees; mean acetabular version 12 degrees (range, 8 to 16 degrees) with 8 hips of <15 degrees. At 1-year follow-up, the mean Harris Hip Score was 95.8 (range, 84.7 to 100).

CONCLUSIONS

Early results suggest that SHD is a safe approach to treat an incomplete reduction following posterior hip instability and is effective for identification and treatment of acute intra-articular pathology. Acetabular dysplasia, relative acetabular retroversion, and/or decreased femoral offset may be risk factors for posterior hip instability in adolescents.

LEVEL OF EVIDENCE

Level IV.

MRI as a reliable and accurate method for assessment of posterior hip dislocation in children and adolescents without the risk of radiation exposure

BACKGROUND

Posterior hip dislocation in children and adolescents may involve the non-ossified posterior acetabular wall. Plain radiographs and computed tomography (CT) have been shown to underestimate injury to the unossified acetabulum as well as associated soft-tissue structures.

OBJECTIVE

The purpose of this study was to describe findings on radiographs, CT and magnetic resonance imaging (MRI) after posterior hip dislocation in a series of adolescents and to report the intraoperative findings, which are considered the gold standard. Measurements of the posterior wall length using MRI and CT scans were also performed.

MATERIAL AND METHODS

After institutional review board approval, 40 patients who sustained a traumatic posterior dislocation of the hip between September 2007 and April 2014 were identified. Inclusion criteria were (1) age younger than 16 years old and (2) availability of MRI obtained following closed reduction of the hip. Eight male patients and one female patient with an average age of 13.2 years (range: 10.1-16.2 years) underwent hip MRI following posterior dislocation. Seven of the nine patients also underwent evaluation by CT. Plain radiographs, CT scans and MRI were evaluated in all patients by a single pediatric radiologist blinded to surgical findings for joint space asymmetry, posterior wall fracture, femoral head fracture, labrum tear, complete or partial ligamentum teres rupture and presence of intra-articular fragments. Six patients underwent surgical treatment and the intraoperative findings were compared with the imaging findings.

RESULTS

CT identified all bone injuries but underestimated the involvement of posterior wall fractures. Assessment of the posterior wall size and fracture displacement was possible with MRI. All surgically confirmed soft-tissue injuries, including avulsion of the posterior labrum, were identified preoperatively on MRI. The measurement of posterior wall length was not statistically different using CT and MRI.

CONCLUSION

Intraoperative pathological findings at the time of open surgical treatment were universally recognized on MRI but not on CT scans. MRI should be considered for evaluation of the hip following closed reduction for the treatment of a posterior dislocation in children and adolescents as it reliably allows assessment of intra-articular pathology without the risk of radiation exposure.

Arthroscopic and imaging findings after traumatic hip dislocation in patients younger than 25 years of age

The aim of this study is to identify intra-articular pathology and loose bodies during arthroscopic examination of young patients after hip dislocation and to correlate arthroscopic findings with preoperative imaging. Twelve hips in 12 patients (eight males, four females; mean age 16.3 years, range 11–25 years) underwent hip arthroscopy after traumatic hip dislocation. Medical records, imaging studies and intra-operative images were reviewed to determine the damage to the hip joint, acetabular morphology, including labral and/or cartilage injury and presence of loose bodies. Imaging findings were compared with arthroscopic findings and treatment. All 12 patients underwent arthroscopy, which was performed an average of 59 (range 1–359, median 17.5) days after dislocation. Ten patients had posterior hip dislocations and two patients had obturator dislocations. All patients underwent closed reduction as initial management, with one incongruent reduction. Eleven patients had computed tomography scans and four patients had magnetic resonance imaging (MRI) with three patients having both modalities. Loose bodies were identified in 6/12 (50%) patients on pre-operative imaging and in 8/12 (67%) patients at arthroscopy. The two patients with unidentified loose bodies on imaging did not have a preoperative MRI. Five patients had acetabular cartilage injuries and three patients had femoral-sided cartilage injuries. Eight patients had labral injuries at arthroscopy. Intra-articular injuries and loose bodies are common in adolescent and young adult patients undergoing arthroscopy following traumatic hip dislocation. Further studies are needed to determine whether arthroscopy after traumatic dislocation may play a role in hip preservation following these injuries.

Traumatic Anterior Dislocation of Hip in a Child - Case Report

Traumatic hip dislocation in children is relatively rare accounting for about 5% of all hip dislocations. Most of the hip dislocations seen in children are of the posterior type but the much rarer anterior and anterior-inferior (obturator) types have also been described. We present the case of an eight years old girl with an obturator type of hip dislocation following trivial trauma. She was treated with closed reduction and immobilisation in skin traction for three weeks. She was followed up closely for one year and did not develop any complications during that period.

Epiphysiolysis of the femoral neck due to closed reduction of an adolescent hip dislocation with a 4-year follow-up: a case report and review of the literature

This case study discusses a 13-year-old girl diagnosed with a displaced Salter Harris II fracture of the proximal femoral epiphysis post reduction of a dislocated hip. Radiographs before reduction revealed a small fracture of the inferomedial femoral head. This, however, did not induce concern before reduction. The patient underwent reparative surgery of the epiphysis only to develop a collapsed femoral head, which was remedied through total hip arthroplasty. A decrease in blood flow, the delicacy in reduction, and unknown predispositions might have been contributing factors toward the unique development in this case.

Traumatic posterior hip dislocation and ipsilateral distal femoral fracture in a 22-month-old child: a case report

Minor trauma may cause hip dislocation in young children because of physiologic hip joint laxity and the soft cartilaginous structure of the acetabulum. In this work, we report on a 22-month-old boy with right-sided traumatic posterior hip dislocation and ipsilateral distal femoral fracture because of an outdoor motor vehicle accident. The patient was treated with emergency closed reduction and one and a half hip spica under general anaesthesia. The femoral fracture and hip dislocation were healed smoothly without any complication. Traumatic hip dislocation is rare in children, which may occur after trivial trauma. Prognosis is better in younger patients with low-energy trauma and in cases treated early.

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.

Potential contribution of femoroacetabular impingement to recurrent traumatic hip dislocation

A 16-year-old boy sustained a traumatic posterior dislocation of the right hip. After initial closed reduction, the hip spontaneously redislocated within 2 days. Four days after the initial dislocation, the patient was transferred to the authors' institution, where a radiographic workup showed a severe capsular and labral disruption from the posterior aspect of the acetabulum. Subsequently, the patient underwent operative treatment using the technique of surgical hip dislocation through a digastric osteotomy as described by Ganz. Using this approach, the avulsed capsulolabral complex as well as the pathological head-neck junction, which is suspected to be a lever for the femoral head, could be fully addressed. The authors recommend further radiographic studies to evaluate the underlying pathology in traumatic dislocation of the hip as well as the described surgical approach, which leads to successful treatment of the entire pathology.

Traumatic hip dislocation in a 3-year-old girl

Traumatic hip dislocation in the pediatric patient requires much less energy than in an adult, yet it remains a rare diagnosis. We report the case of a 3-year-old girl who dislocated her right hip when bindings failed to release as she skied downhill. The hip was promptly reduced in the nearest trauma center, and at 18 months after injury, there is no evidence of avascular necrosis. The potential risk of avascular necrosis is significant, and the risk rises greatly when reduction is delayed beyond 6 hours. Reduction can be safely performed in the emergency department, although up to 25% of cases will require open reduction in the operating room. A high index of suspicion is warranted to not miss the "golden window" and achieve satisfactory reduction in a timely fashion.

[Acute traumatic and especially neglected traumatic hip dislocations are very rare in children]

We report about the first hip arthroscopies of extracapsular neglected hip dislocations with concomitant injuries in two children (2 and 4 years old). The major problem of traumatic hip dislocation is avascular necrosis. Further problems are possible concomitant injuries. It is important not to cause further damage by therapeutic procedures. In a 4-year-old child the hip could be reduced under visualization and in a 2-year-old child with epiphyseal fracture the extent of the operation could be reduced. In both children large avulsion injuries of the ligamentum capitis femoris could be resected via hip arthroscopy. Hip arthroscopy can reduce surgical morbidity considerably and can possibly contribute to prevention of the feared avascular necrosis of the femoral head.

Standard radiographs and computed tomographic scan underestimating pediatric acetabular fracture after traumatic hip dislocation: report of 2 cases

Posterior wall acetabular fractures are rare in the pediatric patient but require proper management to prevent significant complications. Plain radiographs and computed tomography scans are standard diagnostic imaging used with clinical examination of hip stability to determine if the injury requires open reduction and internal fixation. Two cases are presented of adolescent traumatic hip dislocations and posterior wall fractures in which radiography underestimated the extent of the posterior wall fracture. In one case, a magnetic resonance imaging study more clearly characterized the injury. Because the ossification of the posterior wall occurs throughout adolescence, magnetic resonance imaging may be a useful tool in characterizing these fractures and assisting with surgical planning.

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.

Distal focal femoral deficiency

This report represents an interesting case of a rare distal focal femoral deficiency with a complication of hip dislocation. The deformity at the distal femur was erroneously given an initial diagnosis of proximal focal femoral deficiency, and we believe that other similar patients have been given this incorrect diagnosis. Additional reports of such patients will allow further identification of associated pathology. This study describes the features of distal focal femoral deficiency, potential orthopaedic concerns, and proposes a classification scheme for this pathology.

Traumatic transepiphyseal separation of the upper femoral epiphysis following seizures in a 5-month-old child: a case report

INTRODUCTION

Traumatic transepiphyseal separation of the upper femoral epiphysis is a rare lesion of the hip in children.

CASE REPORT

We report a case of conservative treatment of transepiphyseal separation of the upper femoral epiphysis following tonic/clonic seizures in a 5-month-old child. Magnetic resonance imaging confirmed the diagnosis The fracture was maintained with hip spica cast for 6 weeks. At the age of 2, complete healing of the lesion including femoral neck remodeling was noted on frontal and lateral radiographs. There was no radiological evidence of AVN or premature closure of the physis. He continues to be followed up.

DISCUSSION

Because of the remodeling potential in young children, we assume not to perform additional reduction procedures in such traumatic lesions.

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.

[Traumatic hip dislocations in children]

PURPOSE OF THE STUDY

Traumatic hip dislocation is a rare event in children. Appropriate management remains a subject of debate. The purpose of this study was to investigate the epidemiological, therapeutic features of this situation and the long-term outcome after treatment.

MATERIAL AND METHODS

This was a retrospective analysis of 15 traumatic hip dislocations collected over a period of 20 years in pediatric patients with at least two years follow-up. We searched for predisposing factors and factors affecting prognosis.

RESULTS

The series included 11 boys and three girls, mean age eight years. Dislocation was posterior in 13 hips and anterior in two. Time to reduction was less than 3h in eight cases, 3-6h in five and greater than 6h in two. After reduction, traction was performed in nine children, for 20 days on average, followed in five cases by immobilization for 40 days on average. Five hips were immobilized directly after reduction. We identified two groups by age: group 1 with dislocations in children aged less than six years (seven children) were characterized by low-energy trauma. Dislocation was not associated with other lesions. Predisposing factors (overt ligament hyperlaxity, insufficient superolateral head cover, coax valga) were noted in six children. Reduction was simple. Later treatment consisted in immobilization with a pelvispedious cast for 30-45 days. Group 2 were dislocations in children aged over six years (seven children) victims of high-energy trauma. Associated injuries were frequent. Predisposing factors were not present. At mean 11 years follow-up, all hips are considered normal clinically. The radiograph was normal for 14 hips. In one case, there was a slight coax magna. In three patients, defective femoral head cover persisted. Coxa valga persisted in two patients.

DISCUSSION

Traumatic dislocation of the hip joint is rare in very young children, but results from a minimally traumatic event. This suggests the presence of predisposing factors in this category of patients, particularly capsuloligamentary hyperlaxity. After reduction, immobilization can be recommended. Traumatic hip dislocations in children are different from the adult variety due to their rarity, the general absence of associated fractures, easy reduction and better prognosis. The epidemiological and therapeutic features in children older than six years are however similar to those in adults.

Acetabular avulsion fracture in a 13-year-old patient after a minor trauma

The pelvis fracture in children is extremely rare, and only in about 10% of these cases the acetabulum is involved. According to the literature, such acetabulum fractures have been exclusively reported after a major trauma. We report the case of a 13-year-old previously healthy patient, who sustained a posterior wall fracture of the right acetabulum after a minor trauma while playing football. The patient was managed with an open reduction and internal fixation of the fracture through 3 single lag screws. In the 2-year follow-up, the patient did not have any functional impairment and has returned to all usual activities. This case shows that a seemingly inadequate trauma can result in an acetabular fracture in children. Therefore, a correct workup leading to the diagnosis should be carried out. The treatment of those fractures follows the known principles of the traumatology in adults. Because the injury mechanism and the age of our patient are typical for avulsion fractures of the pelvis, a similar mechanism is discussed for this reported posterior wall fracture of the acetabulum.