Trends in the Use of Total Hip Arthroplasty in the Pediatric Population: A Review of the Literature.

Current literature shows that the utilization of total hip arthroplasty (THA) to address pediatric hip pathology has seen a significant rise worldwide in recent decades. However, performing THA in pediatric patients presents unique challenges due to their increased activity levels, varying skeletal maturity, and diverse medical conditions. These challenges have relegated THA to a secondary option for young patients. Nonetheless, despite these difficulties, recent studies have demonstrated a growing prevalence of THA in pediatrics. Consequently, there is an urgent need for a comprehensive review of the existing literature on this topic. In this study, we examined large database and single-institution studies involving pediatric patients aged 21 years and under who underwent THA. The primary indications for THA in this population were osteoarthritis, osteonecrosis, and inflammatory arthritis. To ensure informed decision-making for pediatric patients, it is crucial to gather consolidated information on trends and outcomes related to THA indications. This review aims to provide insights into these trends and facilitate better decision-making for the treatment of pediatric patients.

MRI assessment of femoral head docking following closed reduction of developmental dysplasia of the hip.

AIMS: Eccentric reductions may become concentric through femoral head 'docking' (FHD) following closed reduction (CR) for developmental dysplasia of the hip (DDH). However, changes regarding position and morphology through FHD are not well understood. We aimed to assess these changes using serial MRI. METHODS: We reviewed 103 patients with DDH successfully treated by CR and spica casting in a single institution between January 2016 and December 2020. MRI was routinely performed immediately after CR and at the end of each cast. Using MRI, we described the labrum-acetabular cartilage complex (LACC) morphology, and measured the femoral head to triradiate cartilage distance (FTD) on the midcoronal section. A total of 13 hips with initial complete reduction (i.e. FTD < 1 mm) and ten hips with incomplete MRI follow-up were excluded. A total of 86 patients (92 hips) with a FTD > 1 mm were included in the analysis. RESULTS: At the end of the first cast period, 73 hips (79.3%) had a FTD < 1 mm. Multiple regression analysis showed that FTD (p = 0.011) and immobilization duration (p = 0.028) were associated with complete reduction. At the end of the second cast period, all 92 hips achieved complete reduction. The LACC on initial MRI was inverted in 69 hips (75.0%), partly inverted in 16 hips (17.4%), and everted in seven hips (7.6%). The LACC became everted-congruent in 45 hips (48.9%) and 92 hips (100%) at the end of the first and second cast period, respectively. However, a residual inverted labrum was present in 50/85 hips (58.8%) with an initial inverted or partly inverted LACC. CONCLUSION: An eccentric reduction can become concentric after complete reduction and LACC remodelling following CR for DDH. Varying immobilization durations were required for achieving complete reduction. A residual inverted labrum was present in more than half of all hips after LACC remodelling.Cite this article: Bone Joint J 2023;105-B(2):140-147.

Beware of open triradiate cartilage: 1 in 4 patients will lose > 10° of correction following posterior only fusion.

PURPOSE: As 2-year follow-up may not be sufficient to assess the risk of curve progression following fusion in immature patients with adolescent idiopathic scoliosis (AIS), this study reports on 5-year outcomes of AIS patients, factoring in maturity and surgical approach, to determine whether immature patients are at risk of continued curve progression beyond 2 years. METHODS: A multicenter database was reviewed for AIS patients who underwent spinal fusion with pedicle screw fixation and who had both 2 and 5-year follow-up. Radiographic and SRS-22 scores were compared between three groups: open triradiate cartilage-posterior fusion (OTRC-P), OTRC-combined anterior/posterior fusion (OTRC-APSF), and closed TRC (CTRC, matched to OTRC-P group). RESULTS: 142 subjects were included (67 OTRC-P, 8 OTRC-APSF, 67 CTRC). Main curve type (p = 0.592) and size (p = 0.117) were not different between groups at all timepoints. Compensatory curve size was similar at all timepoints for OTRC-P and CTRC, with a slight increase for OTRC-APSF from immediate postoperative to 5 years. At 5 years, OTRC-P had > 10° loss of correction in 25% of patients, which was greater than in the CTRC (6%) and OTRC-APSF (0%) groups (p = 0.002). No significant differences were found in loss of correction of the compensatory curve or in SRS-22 scores between groups. CONCLUSIONS: Compared to those with CTRC and those treated with anterior/posterior fusion, patients with OTRC treated with posterior fusion had an increased risk of main curve progression greater than 10°, with some continued loss of correction after 2 years. This did not appear to affect patient-reported outcomes.

Dual modality of vertebral body tethering : anterior scoliosis correction versus growth modulation with mean follow-up of five years.

AIMS: Vertebral body tethering (VBT) is a non-fusion technique to correct scoliosis. It allows correction of scoliosis through growth modulation (GM) by tethering the convex side to allow concave unrestricted growth similar to the hemiepiphysiodesis concept. The other modality is anterior scoliosis correction (ASC) where the tether is able to perform most of the correction immediately where limited growth is expected. METHODS: We conducted a retrospective analysis of clinical and radiological data of 20 patients aged between 9 and 17 years old, (with a 19 female: 1 male ratio) between January 2014 to December 2016 with a mean five-year follow-up (4 to 7). RESULTS: There were ten patients in each group with a total of 23 curves operated on. VBT-GM mean age was 12.5 years (9 to 14) with a mean Risser classification of 0.63 (0 to 2) and VBT-ASC was 14.9 years (13 to 17) with a mean Risser classification of 3.66 (3 to 5). Mean preoperative VBT-GM Cobb was 47.4° (40° to 58°) with a Fulcrum unbend of 17.4 (1° to 41°), compared to VBT-ASC 56.5° (40° to 79°) with 30.6 (2° to 69°)unbend. Postoperative VBT-GM was 20.3° and VBT-ASC Cobb angle was 11.2°. The early postoperative correction rate was 54.3% versus 81% whereas Fulcrum Bending Correction Index (FBCI) was 93.1% vs 146.6%. The last Cobb angle on radiograph at mean five years' follow-up was 19.4° (VBT-GM) and 16.5° (VBT-ASC). Patients with open triradiate cartilage (TRC) had three over-corrections. Overall, 5% of patients required fusion. This one patient alone had a over-correction, a second-stage tether release, and final conversion to fusion. CONCLUSION: We show a high success rate (95%) in helping children avoid fusion at five years post-surgery. VBT is a safe technique for correction of scoliosis in the skeletally immature patient. This is the first report at five years that shows two methods of VBT can be employed depending on the skeletal maturity of the patient: GM and ASC. Cite this article: Bone Jt Open 2022;3(2):123-129.

Retrospective analysis of traumatic triradiate cartilage injury in children.

BACKGROUND: To summarize and analyze the epidemiological characteristics, treatment and corresponding curative effect of triradiate cartilage injury(TCI) in children after trauma, to provide a theoretical basis for early diagnosis and improvement of treatment. METHODS: The TCI was classified according to Bucholz classification, and the final curative effect was evaluated with Harris Hip Score and imaging examination during follow-up. Finally, a comprehensive analysis was made by reviewing the cases in the literature combined with the patients in our hospital. RESULTS: A total of 15 cases (18 hips) of triradiate cartilage injuries were collected in our hospital. There was 1 hip with type I injury, nine hips with type II injury, two hips with type IV injury, one hip with type V injury and five hips with type VI injury. Among the 12 cases with complete follow-up, the bone bridge was found in or around the triradiate cartilage in 8 cases, early fusion of triradiate cartilage occurred in 5 patients, 3 cases had hip dysplasia, 4 cases had a subluxation of the femoral head, and HHS was excellent in 8 cases and good in 4 cases. CONCLUSION: The early diagnosis of TCI is still a difficult problem. Conservative treatment is often the first choice. The overall prognosis of acetabular fractures involving triradiate cartilage is poor. The formation of the bone bridge in triradiate cartilage usually indicates the possibility of premature closure, which may lead to severe complications of post-traumatic acetabular dysplasia and subluxation of the femoral head.

San Diego pelvic osteotomy in patients with closed triradiate cartilage.

PURPOSE: A San Diego pelvic osteotomy is frequently used as part of the surgical treatment of neuromuscular patients with hip displacement. This short-term follow-up study assesses the effectiveness of this osteotomy in patients with closed triradiate cartilage compared with open triradiates. METHODS: Retrospective review of 43 patients (44 hips) with neuromuscular hip disease who underwent a San Diego pelvic osteotomy to correct hip displacement. In all 24 hips had open triradiate cartilage at the time of surgery and 20 hips were closed. Centre edge angle (CEA), acetabular angle (AA) and Reimer's index (RI) were recorded from preoperative, postoperative and the latest follow-up radiographs and statistical analysis was performed. RESULTS: CEA improved by 39° (7° to 69°) in the open group and 30° (9° to 80°) in the closed group from preoperative radiographs to postoperative, with no significant difference in improvement between groups (p = 0.084). There was no significant difference in AA between the open (improved by 11° (3° to 23°)) and closed (improved by 10° (4° to 21°)) groups (p = 0.65). RI improved from 61% to 11% in the open group and 51% to 12% in the closed group. There was no statistically significant difference between groups in RI at preoperative, immediate postoperative and final follow-up radiographs. At latest follow-up, CEA, AA and RI all remained relatively stable in both groups. CONCLUSIONS: San Diego pelvic osteotomy is equally effective in improving radiographic parameters in neuromuscular patients with both open and closed triradiate cartilage. This study challenges the notion that closed triradiate cartilage is a contraindication to a San Diego pelvic osteotomy. LEVEL OF EVIDENCE: III.

Maturation of pelvic ossification centers on computed tomography in normal children.

BACKGROUND: The pelvis is composed of three paired primary ossification centers: the pubis, the ischium and the ilium. During maturation, multiple secondary ossification centers can be seen in the synchondroses between these bones and in the pelvic apophyses. The fragmented appearance of these centers can be confused with pathology. OBJECTIVE: To examine development of pelvic ossification centers by CT and determine normal appearance throughout childhood. MATERIALS AND METHODS: Three pediatric radiologists reviewed 325 pelvic CT scans in children and young adults 5-18 years old and graded 6 pelvic ossification centers to evaluate maturational changes in critical structures. RESULTS: Rate and progression of ossification and age at complete fusion vary with gender at the different ossification centers in the growing pelvis. CONCLUSION: Knowledge of the normal CT appearance of ossification centers throughout childhood is important to differentiate the normal appearance from pathology.

An unusual localization of chondroblastoma: The triradiate cartilage; from a case report a reconstructive technique proposal with imaging evolution.

INTRODUCTION: Chondroblastoma (also known as Codman tumor) is a rare intermediate grade cartilaginous neoplasm, representing less than 1% of all primary bone tumors; it characteristically arises in the epiphysis or apophysis of a long bone in young patients, predominantly males. The most frequent location of chondroblastoma is the humerus (70% incidence rate) and more rarely it is located in the pelvis. When it affects the hip, the triradiate cartilage is the most common site. MATERIALS AND METHODS: An unusual case of Chondroblastoma located in the triradiate cartilage is reported. The surgical technique and the imaging are emphasized: a homoplastic fascia latae was used to reconstruct the cartilage layer then a layer of engineered homoplastic bone was superiorly positioned to reconstruct the subchondral bone; the residual cavity was filled with a homoplastic hemi-femoral head concavity molded to best correspond to the acetabular roof and morcelized bone. RESULTS: At four years of follow-up the patient is pain free and able to walk without crutches; the imaging showed a rearrangement of the trabecula distribution following the lines of force. CONCLUSIONS: The suggested technique could be a valid option in reconstructing acetabular roof in benign lesions. A correct radiological assessment could be helpful for diagnosis and an early detection of local recurrence.

Traumatic pelvic fractures in children and adolescents.

Although traumatic pelvic fractures in children are relatively rare, these injuries are identified in about 5% of children admitted to level 1 trauma centers after blunt trauma.1-4 Such injuries differ from adult pelvic fractures in important ways and require distinct strategies for management. While the associated mortality rate for children with pelvic fractures is much lower than that for adults, the patient may require urgent surgical intervention for associated life-threatening injuries such as head trauma and abdominal injury. Unstable pelvic ring fractures should be acutely managed using an initial approach similar to that used in adult orthopedic traumatology. Although very few pediatric pelvic fractures will ultimately need surgical treatment, patients with these injuries must be followed over time to confirm proper healing, ensure normal pelvic growth, and address any potential complications. The trauma team suspecting a pelvic fracture in a child must understand the implication of such a finding, identify fracture patterns that increase suspicion of associated injuries, and involve pediatric or adult orthopedic specialists as appropriate during the management of the patient.

Age- and gender-related characteristics of the pubic symphysis and triradiate cartilage in pediatric computed tomography.

BACKGROUND: There is little information on the pubic symphysis' normal CT appearance in children. OBJECTIVE: We sought to generate age-, gender- and maturity-related symphyseal width appearances in CT scans. MATERIALS AND METHODS: Pelvic CT scans performed for any reason during a 6-year period in patients younger than 18 years were retrospectively analyzed. The symphysis width was measured in the axial plane and the triradiate cartilage was classified as open or closed. RESULTS: Four hundred twenty-seven CT scans were evaluated and 350 remained for analysis. Age- and gender-related measurements of the symphysis width are illustrated on various centile graphs. When grouping children by age in years 0-6, 7-11, 12-15 and 16-17, mean (standard deviation) symphysis width was 5.4 mm (0.9), 5.3 mm (1.1), 4.1 mm (1.1) and 3.5 mm (1.0), respectively, in girls and 5.9 mm (1.3), 5.4 mm (1.2), 5.2 mm (1.1) and 4.0 mm (1.0), respectively, in boys. Boys and girls were significantly different in the age groups 12-15 years (P<0.001) and 16-17 years (P=0.04). In the mature pelvis, the symphyseal gap is significantly (P<0.001) shorter in both genders, and in girls compared to boys (P=0.04). CONCLUSION: The pubic symphysis width in children differs according to age, gender and maturity. The reference values published herein may help detect symphyseal injury.

Virtual reconstruction and geometric morphometrics as tools for paleopathology: a new approach to study rare developmental disorders of the skeleton.

Survey studies of osteoarchaeological collections occasionally yield specimens exhibiting rare skeletal developmental disorders. Beyond paleopathological diagnosis, however, it is often difficult to gain insight into the processes, mechanisms, and consequences of the pathology, notably because archaeological specimens are often fragmentary. Here, we propose a combination of virtual reconstruction (VR) and geometric morphometrics (GM) to address these issues. As an example, we use VR to reconstruct the only known archaeological specimen exhibiting persistence of the pelvic triradiate cartilage and compare it via GM with a set of healthy pelvises representing both sexes and different ontogenetic stages. Our results evidence (i) a marked deviation of the pathological pelvis from the adult mean shape, (ii) the retention of typical male features, and (iii) the retention of a paedomorphic ratio between iliac and ischiopubic size. Altogether, such data offer new insights into the modularity and integration of pelvic ontogeny, while at the same time demonstrating the usefulness of a combined VR/GM approach as complement to classical methods of paleopathology.

Spatial changes of the peri-acetabular pelvic in developmental dysplasia of the hip---a combined 3-dimentional computed tomography (3D-CT) study in patients and experimental study in rats.

Few previous studies noticed the three bony structures that formed the acetabulum in developmental dysplasia of the hip (DDH). This study aimed at investigating the spatial changes of the peri-acetabular pelvis in developmental dysplasia of the hip through radiological evaluation of the patients and experimental observations in rat models. 115 unilateral DDH patients were studied through 3D-CT. In reconstruction workstation, the iliopubic inner plate angle, ilioischial inner plate angle and ischialpubic inner plate angle were measured and compared. 58 neonatal Wistar rats were divided into two groups and the rats in experiment group were swaddled to establish DDH models. The hips were sectioned, stained. The same three angles were measured and compared. The ilioischial inner plate angle of the affected hip decreased while the ischialpubic inner plate angle increased compared to those of the contralateral side. The iliopubic inner plate angle showed no difference between the affected and unaffected hips. In animal models we observed the same pathological pattern. The three angles measured on the sections showed similar tendency as those in the patients with DDH. The ischium rotates up and forwardly around the posterior and vertical limbs of the triradiate cartilage complex in DDH, just as a lifted piece of Pizza.