Staying ahead of the curve: the use of spinopelvic parameters to predict curve progression and bracing success in adolescent idiopathic scoliosis.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: To investigate radiographic sagittal and spinopelvic parameters of patients with adolescent idiopathic scoliosis (AIS) treated with bracing and assess differences among those treated successfully and unsuccessfully. AIS is a three-dimensional deformity of the spine, sharing an intricate relationship with pelvic morphology. However, the most relevant predictors of curve progression have historically been coronal parameters and skeletal maturity. Sagittal and spinopelvic parameters have not been thoroughly investigated as predictors of curve progression and brace treatment success. METHODS: Retrospective review of AIS patients who underwent brace treatment. Coronal Cobb angles (CC), pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), thoracic kyphosis (TK), lumbar lordosis (LL), and thoracic spinopelvic angles (T1SP, T9SP) were measured prior to initiation of bracing. The sagittal and spinopelvic parameters of patients requiring surgical treatment due to curve progression were compared to those treated successfully with bracing. RESULTS: No significant differences were found for age, race, gender, Risser category (0/1 vs 2/3), initial CC, TK, LL, T1SP, or T9SP between cohorts. The cohort requiring surgery had significantly lower PI (p < 0.001, 42.0 v. 54.6), SS (p < 0.001, 37.0 v. 44.5), and PT (p = 0.003, 5.0 v. 10.2) compared to those successfully treated with bracing. Multivariable models controlling for Risser stage and Initial CC revealed the odds for successful brace treatment increases with an increase in PI (OR = 1.47, CI 1.18-1.83, p < 0.001), SS (OR = 1.26, CI 1.07-1.48, p = 0.006), and PT (OR = 1.43, CI 1.09-1.86, p = 0.006) (Table 3). The odds of successful brace treatment is given per one-unit increase for each radiographic measure after adjusting for Initial CC and Risser sign which were forced into each multivariable model. CONCLUSIONS: Spinopelvic parameters may indicate potential spine adaptability and skeletal maturity. For these reasons, we proposed that spinopelvic parameters may be a potential predictor of curve progression and brace treatment success. Our results demonstrated a higher risk of curve progression with lower PI, PT, or SS which support this hypothesis, however, given the small sample size and high variability, the magnitude of this effect should be viewed with caution and should serve as an impetus to further, larger scale studies to investigate the value spinopelvic parameters in curve progression and bracing efficacy. LEVEL OF EVIDENCE: IV.

Gradual Deformity Correction in Blount Disease.

BACKGROUND: Blount disease is a disorder of the posteromedial proximal tibial physis which causes a progressive varus, procurvatum, and internal rotation deformity of the tibia. Untreated, it can cause significant limb malalignment. The goal of this study is to evaluate the results of correction of Blount disease using types of external fixation. METHODS: We conducted a retrospective review of 41 patients (51 limbs) who underwent correction of Blount disease with an Ilizarov external fixator or a Taylor spatial frame (TSF) by a single surgeon. The medial proximal tibial angle (MPTA), mean axis deviation (MAD), posterior proximal tibial angle, and joint line congruence angle (JLCA) were measured on radiographs preoperatively, at frame removal and at final follow-up. RESULTS: The average age at treatment was 9.6 years old, with a mean follow-up time of 34 months. Mean preoperative MPTA, MAD, and JLCA were significantly improved at the time of frame removal as well as at final follow-up with no significant changes in correction between the time of frame removal and final follow-up. There was no difference in MPTA and MAD in patients treated with an Ilizarov frame versus a TSF. MPTA, MAD, and JLCA all significantly improved regardless of the underlying diagnosis (infantile vs. adolescent Blount disease) or history of prior surgical intervention. The most common complication was superficial pin-site infection. CONCLUSIONS: Both Iliazarov and TSF are viable treatment options for infantile and adolescent Blount disease, with the ability to significantly improve both the limb mechanical axis and the mechanical axis of the affected tibia. Correction can be attained regardless of whether patients have previously failed surgical intervention. LEVEL OF EVIDENCE: Level III-retrospective comparative study.

Analysis of the impact of race on blood transfusion in pediatric scoliosis surgery.

INTRODUCTION: Surgical correction of pediatric scoliosis is associated with significant blood loss. Minimizing estimated blood loss and blood transfusion is beneficial as transfusions have been associated with increased morbidity, including risk of surgical site infections, longer hospitalizations, and increased cost. Although there is evidence that African-American or Black adults are more likely to require intraoperative blood transfusion compared with Caucasian or White adults, the reasons for this difference are unclear. METHODS: The electronic records for all patients <18 y/o undergoing primary corrective scoliosis surgery by a single pediatric orthopedic surgeon at a single academic medical center between 2013 and 2015 were collected and reviewed. Multivariate models were performed to assess the association between Black race and blood loss/transfusion in primary pediatric scoliosis surgery. RESULTS: In a multivariate model, Black race was independently associated with 1.61 times higher estimated blood loss than White race (P < .01; 95% CI = 1.16-2.23). Additionally, compared to a White patient, the odds a Black patient received blood transfusion was 6.25 times higher (P = .03; 95% CI = 1.56-25.06) and among the patients who received blood transfusion, Black race was independently associated with 2.61 times greater volume of blood transfusion than White race (P < .01; 95% CI = 1.54-4.41). CONCLUSION: Black race was independently associated with increased estimated blood loss, increased rate of blood transfusion, and increased amount of blood transfused during surgical correction of pediatric scoliosis. Further investigation is needed to better understand the etiology of the disparity and assess opportunities for improving outcomes.

Looking beyond the exome: a phenotype-first approach to molecular diagnostic resolution in rare and undiagnosed diseases.

PurposeTo describe examples of missed pathogenic variants on whole-exome sequencing (WES) and the importance of deep phenotyping for further diagnostic testing.MethodsGuided by phenotypic information, three children with negative WES underwent targeted single-gene testing.ResultsIndividual 1 had a clinical diagnosis consistent with infantile systemic hyalinosis, although WES and a next-generation sequencing (NGS)-based ANTXR2 test were negative. Sanger sequencing of ANTXR2 revealed a homozygous single base pair insertion, previously missed by the WES variant caller software. Individual 2 had neurodevelopmental regression and cerebellar atrophy, with no diagnosis on WES. New clinical findings prompted Sanger sequencing and copy number testing of PLA2G6. A novel homozygous deletion of the noncoding exon 1 (not included in the WES capture kit) was detected, with extension into the promoter, confirming the clinical suspicion of infantile neuroaxonal dystrophy. Individual 3 had progressive ataxia, spasticity, and magnetic resonance image changes of vanishing white matter leukoencephalopathy. An NGS leukodystrophy gene panel and WES showed a heterozygous pathogenic variant in EIF2B5; no deletions/duplications were detected. Sanger sequencing of EIF2B5 showed a frameshift indel, probably missed owing to failure of alignment.ConclusionThese cases illustrate potential pitfalls of WES/NGS testing and the importance of phenotype-guided molecular testing in yielding diagnoses.

Neuromuscular Scoliosis: Current Concepts.

Scoliosis is a common deformity in neuromuscular disorders. This spinal deformity usually presents at an early age, rapidly progresses during growth, and continues to progress even after skeletal maturity. Neuromuscular scoliosis classically involves the entire thoracolumbar spine, often extending to the pelvis and causing pelvic obliquity. Physical examination can be challenging, but it is important to assess the flexibility of the spinal curve and associated joint contractures. Upright anteroposterior and lateral radiographs are the preferred imaging. When formulating a treatment plan, it is important to take into account not only the degree of curvature, but also each patient's needs and quality of life, the potentially high perioperative complication rates, and the natural history of the underlying neuromuscular disorder. Different neuromuscular conditions behave differently and should therefore be treated differently. With the exception of steroids for Duchenne muscular dystrophy, bracing remains the only reliable nonoperative intervention available. Preoperative optimization of medical comorbidities is crucial given the relatively high complication rate. Posterior segmental instrumentation has revolutionized the surgical management of neuromuscular scoliosis and is the most commonly used technique today. Despite reported improvement in postoperative quality of life, there are several limitations with currently used outcome measures that prevent a well-informed discussion on the outcomes after surgery.

Distant Harrington rod migration 35 years after implantation.

Harrington rods have been successfully implanted in thousands of patients for the correction of scoliotic deformity since the 1950s. An exceedingly rare complication of Harrington rod placement is loosening with resultant migration. The authors present a 50-year-old woman who had a single Harrington rod placed when she was 15 years old. Thirty-five years later, she presented with acute sensory changes in her lower extremities. Imaging revealed rod failure and migration of the hardware distally, resulting in penetration of the wall of the rectum. Due to the unique anatomical position of the migrated hardware, sigmoidoscopy was used to directly visualize and remove the rod. The patient ultimately made a full recovery. Rod migration is an exceedingly rare complication that has been described only a few times since the introduction of Harrington rods over 60 years ago. The case herein is particularly unique given the extensive period of time that passed before migration (35 years) and the use of sigmoidoscopy for hardware removal.

Bovine xenograft failures in pediatric foot reconstructive surgery.

BACKGROUND: Structural bone grafting serves an important and necessary role during pediatric foot reconstruction. Different bone grafts have been used for such reconstructions including corticocancellous autografts, allografts, and synthetic grafts. Bovine xenografts represent a novel option with multiple potential advantages; however, there are limited clinical data on the efficacy and success of such grafts. This retrospective case series was performed to review the anecdotally recognized high failure rate of bovine xenograft transplantation in pediatric foot reconstruction at a tertiary institution. MATERIALS AND METHODS: Ten pediatric patients with 13 feet underwent reconstructive procedures involving implantation of bovine xenografts for various foot deformities. The mean age at time of surgery was 14.1 years with an average clinical follow-up of 21.6 months. All patients received lateral column lengthening with additional various other reconstructive procedures performed by 3 separate orthopaedic surgeons in a similar step-wise manner. Clinical outcomes were obtained through a retrospective chart review of standard preoperative and postoperative clinical and radiographic data. RESULTS: Seven of 13 (53.8%) bovine xenografts implanted resulted in clinical symptoms of failure with corresponding radiographic failed graft incorporation. The most common presenting symptom was foot pain with activity and each failure was easily identified on plain radiographs by lucency surrounding the graft sites. All 7 failures required a subsequent revision surgery to remove the bovine graft followed by placement of human iliac crest allograft. After revision surgery, each patient reported subjective improvement in pain and return to daily activity with radiographic evidence of complete incorporation of the graft. CONCLUSIONS: Bovine xenografts used as structural grafts in pediatric foot reconstruction resulted in unacceptably high rates of failure and the need for further revision surgery. For this reason, surgeons should be cautioned against the use of bovine xenograft material in the surgical management of pediatric foot deformity. LEVEL OF EVIDENCE: Level IV case series.

Vascularized fibular grafts for avascular necrosis after slipped capital femoral epiphysis: is hip preservation possible?

BACKGROUND: Avascular necrosis (AVN) of the femoral head is a potential complication in patients with slipped capital femoral epiphysis (SCFE), radiographically occurring in 3-60%. This may lead to early hip fusion or hip arthroplasty. Free vascularized fibular grafting (FVFG) may provide a reasonable means to preserve the femoral head. QUESTIONS/PURPOSES: We asked: (1) What percentage of patients with AVN after SCFE treated with FVFG underwent subsequent THA or hip fusion and what was the lifespan of the FVFG? (2) Did the graft survival rate of FVFG for AVN after SCFE coincide with historically reported rates of FVFG for idiopathic AVN? And (3) did hip function improve after FVFG? METHODS: We retrospectively reviewed 52 patients who underwent FVFG for SCFE. We calculated the longevity of the graft and factors associated with graft survival. Harris hip scores (HHS) were recorded pre- and postoperatively. Minimum followup was 1 month (median, 19 months; range, 1-136 months). RESULTS: Five of the 52 patients (10%) underwent conversion to THA (four) or hip fusion (one). Mean age was greater in these patients than in those not requiring further procedures: 16 versus 13 years. Median graft survival time before arthroplasty/fusion was 12 years (range, 2-16 years) while it is currently 8 years (range, 2-16 years) in patients not undergoing subsequent procedures. HHSs improved 35 points on average (38 points preoperatively to 73 points postoperatively). CONCLUSIONS: In patients undergoing FVFG for AVN secondary to SCFE, 90% have maintained their native hips for 8 years with improved hip function, similar to other published reports of FVFG. Further followup is needed of patients currently retaining their FVFGs as to eventual conversion to THA or fusion. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Osteonecrosis of the femoral head in childhood malignancy.

PURPOSE: Children undergoing chemotherapeutic treatment of malignancies have up to a 9 % incidence of osteonecrosis. The purpose of this article is to determine the time from initiation of chemotherapy to the onset of symptoms and the diagnosis of osteonecrosis of the femoral head in this patient population. METHODS: A retrospective review of the records of 18 patients (29 hips) under 21 years of age with both a diagnosis of osteonecrosis of the femoral head and childhood onset malignancy was undertaken to determine the time from initiation of chemotherapy to the onset of symptoms and diagnosis of osteonecrosis of the femoral head. RESULTS: Mean time from initiation of chemotherapy to the onset of pain was 18.8 months (8.0-49.1). The mean time from development of pain to diagnosis of osteonecrosis was 3.9 months (-13.1 to 25). The mean overall time from initiation of chemotherapy to diagnosis of osteonecrosis was 22.7 months (9.0-54.1). 11/18 patients had bilateral disease. 16/18 patients (21/29 hips) had already progressed to stage 4 osteonecrosis at the time of diagnosis. CONCLUSIONS: There was a high incidence of stage 4 or greater osteonecrosis at the time of diagnosis. Providers caring for these patients should be aware of the potential for osteonecrosis, and the need for prompt diagnosis and referral to an orthopedic surgeon. Screening with advanced imaging studies may be warranted for children undergoing chemotherapeutic regimens for childhood malignancy to prevent delay in the diagnosis and management of this process so that joint preservation therapies remain an option.

Prevalence of painful peroneal tubercles in the pediatric population.

Pain isolated to the lateral aspect of the heel can be difficult to diagnose, particularly in the growing child. Peroneal tendinopathy or frank tears of the peroneal tendons secondary to an enlarged peroneal tubercle has been implicated as a potential source of pain in adults. Neither the prevalence of enlarged peroneal tubercles in the pediatric population nor the number of symptomatic tubercles in children has been elucidated. We conducted a review of children who presented to our institution with foot and/or ankle pain and who underwent 3-dimensional computed tomography. Initially, a radiographic review was undertaken of all computed tomography scans to determine the prevalence of peroneal tubercles in children. The peroneal tubercles were measured and then classified according to height. The children with tubercles 3 mm or greater in height (adult mean height) underwent a more detailed chart review to evaluate for the incidence of painful tubercles. During the study period, 2,689 children were seen for foot and ankle pain, and 367 underwent a computed tomography scan during their treatment course. Of these 367 patients, 57% had a measurable peroneal tubercle, and 162 (44%) met the criteria for chart review. Only 3 adolescents (1.9%) were found to have clinical symptoms and ultimately underwent surgical excision with successful relief of symptoms. Peroneal tubercle hypertrophy appears to exist in the pediatric population; however, in contrast to adults with associated peroneal tendinopathy and tears, the children in our series had isolated painful tubercles without significant tendinopathy. The clinical examination is important in the diagnosis, and treatment by excision appears to be successful. Although a relatively rare etiology of pain, it is important that treating physicians keep this pathologic process in the differential diagnosis, because conservative management might not reduce the pain in these children.

Efficacy of alendronate in adults with cystic fibrosis with low bone density.

As adults with cystic fibrosis (CF) have enjoyed incremental increases in longevity over the last few decades, they have also been suffering from low bone density and its clinical manifestations, fractures and kyphosis. We conducted a placebo-controlled, randomized, double-blinded trial of alendronate (10 mg/day orally) (n = 24) compared with placebo (n = 24) for 1 year in 48 patients to improve bone mineral density at the spine as the primary endpoint. All patients received 800 IU of cholecalciferol and 1,000 mg of calcium carbonate. Both groups were similar in age, sex, CF mutations, bone density T scores, renal function, and body mass index at study onset. The alendronate-treated patients gained (mean +/- SD) 4.9 +/- 3.0% and 2.8 +/- 3.2% bone density after 1 year versus placebo, which lost (mean +/- SD) 1.8 +/- 4.0% and 0.7 +/- 4.7%, in spine and femur bone density, respectively (p < or = 0.001 for the spine; p = 0.003 for the femur). Urine N-telopeptide, a bone resorption marker, levels declined in the treatment group more than in the control group (p = 0.002), consistent with the known antiresorptive effects of bisphosphonates. Alendronate was more effective than placebo in improving spine and femur bone mineral density and is a promising agent for the long-term prevention and management of bone disease in patients with CF.