The Prevalence of Hip Dysplasia on Radiographs for Adolescent Idiopathic Scoliosis.

BACKGROUND: During radiographic assessment of adolescent idiopathic scoliosis (AIS), upright images frequently capture the hip. The purpose of this study was to assess the prevalence of radiographic hip dysplasia on postero-anterior (PA) scoliosis radiographs, as defined as a lateral center edge angle (LCEA) ≤25 degrees. METHODS: All patients with upright PA scoliosis radiographs over a one-year study period at a single tertiary academic medical center (2020 to 2021) were included in the study. Radiographs containing the hip joints were annotated by 3 reviewers for left and right LCEA, and triradiate cartilage (TRC) status. Inter-rater reliability was determined among the 3 reviewers. RESULTS: Two hundred fifty patients {500 hips, 75.6% female, median age 14 [interquartile range (IQR)=3]} had PA scoliosis radiographs that captured the hip, which qualified for analysis. Seventy-four hips (14.8%) demonstrated evidence of dysplasia (LCEA ≤25 deg) in 55/250 patients (22%). The median LCEA was significantly lower in the dysplastic hip cohort (23.9 deg, IQR=4.8 deg), compared with those without dysplasia (33 deg IQR=7.3 deg; P =0.001). A higher percentage of dysplastic hip patients were female than male (72.7% vs. 27.3%). Patients with bilateral dysplasia had a similar LCEA ( 22.9 deg) [to those with unilateral dysplasia (22.9 deg left, 23.9 deg right, P =0.689)]. CONCLUSIONS: In a cohort of 250 AIS patients, 22% demonstrated evidence of hip dysplasia, as defined as an LCEA ≤2 degrees. The dysplastic patients were more likely to be female. Screening for hip symptomatology in AIS patients may be of benefit, considering the frequency of radiographic hip dysplasia in this population. LEVEL OF EVIDENCE: III. Type of Evidence: diagnostic.

Trends in the Utilization of Implants in Index Procedures for Early Onset Scoliosis From the Pediatric Spine Study Group.

INTRODUCTION: Because of the relative rarity of Early Onset Scoliosis (EOS) cases, patient registries were developed to combine clinical information from multiple institutions to maximize patient care and outcomes. This study examines the history and trends regarding the use of growth-friendly devices for index surgical procedures in EOS patients within the Pediatric Spine Study Group database. METHODS: All index growth-friendly implants were queried from registry inception until October 2020. EOS etiology, device/implant type, and geographic area/institution for each procedure were recorded. RESULTS: From 1994 to 2020, 2786 patients underwent index surgery at a mean age of 6.2±2.9 years. There were 908 traditional growing rods (TGR) (32.3%), 922 vertical expandable prosthetic titanium rib devices (VEPTR) (33.1%), 5 hybrid VEPTR/TGR (0.18%), and 951 magnetically controlled growing rods (MCGR) (34.2%) index implants. Fifty-six different institutions reported an index implant, and 5 accounted for 823 (30%) of the cases during the study period. Institutions in the Northeast accounted for more index implants than other regions of the United States. There was a 40% increase in index implant insertions annually when comparing 1994 (3 implants/1 center) to 2018 (234 implants/56 centers), ( P <0.001). Beginning in 2009, there was a 90.9% decrease in the number of TGR/VEPTR procedures (2009: 156 implants/32 centers; 2019: 22 implants/49 centers P =0.001), and a 479% increase in MCGR (2009: 1 implant/1 center; 2018: 197 implants/34 centers ( P =0.005). The overall number of growth-friendly index procedures performed in 2019 (150/49 centers) decreased 34.5% when compared to 2018 (234/48 centers). CONCLUSION: The number of growth-friendly implants reported in the Pediatric Spine Study Group registry as the initial surgical management of EOS increased markedly over the past 20 years. MCGR is currently the predominant type of device utilized for index surgical procedures by group members, surpassing the use of VEPTR and TGR in 2014. There was a significant decrease in index growth-friendly procedures in 2019 compared to 2018. LEVEL OF EVIDENCE: Level IV.

Analysis of Author Gender in the Pediatric Orthopaedic Literature from 2011 to 2020.

INTRODUCTION: Orthopaedic surgery remains a male-dominated specialty. To date there has not been a focused analysis of gender in authorship within the pediatric orthopaedic literature. METHODS: The electronic table of contents from 2011 to 2020 of 3 major pediatric orthopaedic journals [Journal of Children's Orthopaedics (JCO), Journal of Pediatric Orthopaedics (JPO), and Journal of Pediatric Orthopaedics Part B (JPO-B)] were reviewed. Publications were reviewed for the number of articles with at least 1 female author and the number of articles with women listed as first authors. These were compared over the 10-year study period, and by individual year of publication. Statistical analysis included a general linear model with factorial one-way anslysis of variance and Bonferroni post hoc testing. RESULTS: A total of 4097 articles were reviewed. In 2020, there was a significantly higher percentage of articles with a female author when compared with 2011 (64% to 42%, P=0.010). A female was listed as first author in significantly more publications in 2020 as compared with 2011 (23% to 10%, P=0.031). During the 10-year study period, the highest mean proportion of articles with at least 1 female author was seen in JPO (60%), with similar findings in JCO (55%). Significantly fewer articles in JPO-B contained a female author (37%, P=0.001). The highest percentage of publications with a female first author across 10 years was in JCO (22%), followed by JPO (20%). Significantly fewer articles with a female first author were found in JPO-B (9%, P=0.001). CONCLUSION: There is an increasing proportion of publications in the pediatric orthopaedic literature with female authors and female first authors from 2011 to 2020. In addition, there was a statistical difference in female authorship when comparing specific publications, which should be investigated further. LEVEL OF EVIDENCE: Level IV.

A Single Sugar-Tong Splint Can Maintain Pediatric Forearm Fractures.

Displaced pediatric forearm fractures often are treated with closed reduction and immobilization. Recent literature demonstrates no difference in maintaining alignment or needing repeat intervention in patients immobilized with either a single sugar-tong splint or a long-arm cast, but most series include patients with distal fractures. This study included patients 3 to 15 years old who underwent closed reduction and immobilization for displaced midshaft or proximal forearm fractures. Radiographs from the time of injury, after reduction, and at 4-week follow-up were reviewed for coronal and sagittal plane angular alignment. Secondary interventions also were recorded. A total of 121 patients (70 long-arm cast, 51 simple sugar-tong splint) met inclusion criteria. Groups were matched in terms of age (P=.95), sex (P=.41), body mass index (P=.12), and angular deformity prior to reduction in the sagittal (P=.78) and coronal (P=.83) planes. Following closed reduction, sagittal (P=.003) and coronal (P=.002) alignment improved significantly in all patients. At 4-week follow-up, there were no significant differences in sagittal (P=.15) or coronal (P=.68) alignment between the 2 groups. Nine patients underwent a secondary intervention after the index reduction (long-arm cast, n=7; simple sugar-tong splint, n=2), with no statistically significant difference between groups (P=.30). There were no statistically significant differences between patients managed with long-arm cast or simple sugar-tong splint regarding residual sagittal or coronal plane deformity at 4-week follow-up or incidence of secondary intervention. These findings indicate simple sugar-tong splint and long-arm cast appear to be acceptable and equivalent methods of immobilization for these injuries. [Orthopedics. 2021;44(2):e178-e182.].

MRI diagnosis of rubber band constriction syndrome.

Rubber band syndrome is caused by constriction of the wrist from elastic bracelets worn for decorative purposes. Overtime, the fixed or elastic band burrows into the skin and becomes invisible. We present the case of a 2.5-year-old female child presenting to our institution with signs of circumferential swelling and inflammatory changes about the right wrist. MRI of the wrist demonstrated a subcutaneous circular foreign body, which was confirmed at surgery to be a rubber band. Although this disease entity is rare, radiologists can be instrumental in suggesting this diagnosis based on the location involved, ie, wrist, and the imaging findings.

Hemiepiphyseodesis for Juvenile and Adolescent Tibia Vara Utilizing Percutaneous Transphyseal Screws.

BACKGROUND: In juvenile and adolescent tibia vara patients with sufficient growth remaining, implant-controlled hemiepiphyseodesis, or guided growth, can be used to correct deformity. Recent reports have described hardware failure of certain hemiepiphyseodesis implants in overweight patients with tibia vara. We describe our experience using transphyseal screws to correct deformity in this patient population. METHODS: A retrospective chart and radiograph review was conducted on all juvenile and adolescent tibia vara patients who underwent lateral proximal tibial hemiepiphyseodesis using a single transphyseal screw. Charts were queried for preoperative and postoperative mechanical axis deviation, medial proximal tibial angle, lateral distal femoral angle, and postoperative complications or need for further surgery. RESULTS: In total, 14 affected limbs in 9 patients (6 males) who underwent lateral proximal tibial transphyseal screw hemiepiphyseodesis were considered. Average chronologic age at implantation was 10.4 years and average body mass index was 31.7 kg/m. At average 23-month follow-up, the average mechanical axis deviation improved from 46 to 0 mm (P<0.001), and the average medial proximal tibial angle improved from 81 to 92 degrees (P<0.001). No limbs underwent further surgery to correct residual deformity. There were no complications or instances of implant failure associated with the transphyseal screws. CONCLUSIONS: Hemiepiphyseodesis using transphyseal screws is an effective technique to correct deformity in juvenile and adolescent tibia vara patients with sufficient growth remaining. This method can be used safely with few complications and with minimal risk of mechanical failure, even in overweight patients. LEVEL OF EVIDENCE: Level IV-therapeutic.

Clinical and radiographic comparison of single-sugar-tong splint to long-arm cast immobilization for pediatric forearm fractures.

The purpose of this study was to compare the efficacy of a single-sugar-tong splint (SSTS) to a long-arm cast (LAC) in maintaining reduction of pediatric forearm fractures, while avoiding secondary intervention. One hundred patients age 3-15 with a forearm fracture requiring a reduction and immobilization were evaluated (50 LAC and 50 SSTS). Medical records and radiographs were reviewed at injury, postreduction, and at 1, 2, and 4 weeks postinjury. Sagittal and coronal angular deformities were recorded. Any secondary intervention due to loss of reduction was documented. The groups were matched by age (P = 0.19), sex (P = 0.26), mechanism of injury (P = 0.66), average injury sagittal deformity (LAC 27.4°, SSTS 25.4°; P = 0.50), and average injury coronal deformity (LAC 15.5°, SSTS 16°; P = 0.80) At 4 weeks postinjury follow-up, there were no statistically significant differences between use of an SSTS or LAC when comparing postimmobilization sagittal alignment (LAC 10.3 ± 7.2, SSTS 8.4 ± 5.1°; P = 0.46), coronal alignment (LAC 6.9 ± 4.6, SSTS 7.6 ± 9.3°; P = 0.46), or need for repeat manipulation or surgery (LAC 4/50, SSTS 3/50; P = 0.70).

Septic Arthritis of the Hip-Risk Factors Associated With Secondary Surgery.

INTRODUCTION: Septic arthritis of the hip (SAH) is a common condition encountered by pediatric orthopaedic surgeons and is treated with arthrotomy and irrigation. Depending on the response to initial treatment, some patients require surgical treatment beyond the index procedure. The purpose of this study was to investigate risk factors for repeat surgical intervention after initial arthrotomy for presumed SAH. METHODS: A multicenter retrospective review of all children who underwent surgical arthrotomy for presumed SAH over a ten-year period was conducted. Variables queried included demographics, clinical presentation, laboratory parameters, imaging, infecting organism, presence of osteomyelitis, and surgical interventions performed. Logistic regression was used to predict the risk of a second procedure. Chi-square was used to compare patients who required further surgery and those who did not. RESULTS: One hundred and thirty-eight patients (139 hips) qualified for inclusion. The average age at initial surgery was 6.1 years (range, zero to 17 years), and 57% of the patients were male. Concomitant osteomyelitis was diagnosed in 55 cases (40%). An infecting organism was identified from 70 (50%) index intraoperative cultures, with Staphylococcus aureus infections (methicillin-resistant Staphylococcus aureus [MRSA], 27; methicillin-sensitive Staphylococcus aureus, 25) being the most frequent. Fifty-six patients (41%) underwent subsequent surgical intervention, at an average of 5.5 days (range, 2 to 95) from the index procedure. Independent risk factors for repeat surgical procedures included presenting C-reactive protein >10 mg/dL (P = 0.002) and presenting erythrocyte sedimentation rate >40 (P = 0.011). The odds of repeat surgical intervention were significantly increased by the presence of concomitant osteomyelitis (odds ratio, 3.4; P = 0.001) and positive index intraoperative cultures for MRSA (odds ratio, 1.19; P = 0.001). Preoperative MRI before the index procedure was not universal (73/138; 53%), and acquisition of preoperative MRI was not associated with secondary surgical intervention (P = 0.389). DISCUSSION: Forty-one percent of children in this multicenter cohort underwent at least one repeat surgical procedure after the index arthrotomy for management of presumed SAH. Risk factors for return to the operating room include elevated initial erythrocyte sedimentation rate and C-reactive protein, infection with MRSA, and presence of osteomyelitis. LEVEL OF EVIDENCE: Level 3, case-cohort series. Type of evidence, therapeutic.

The Crankshaft Phenomenon.

The crankshaft phenomenon, a progressive rotational and angular spinal deformity that can occur after posterior spinal surgery, has been reported in pediatric patients with idiopathic, congenital, and neuromuscular scoliosis. In the skeletally immature patient, the crankshaft phenomenon is thought to occur secondary to continued growth of the anterior elements of the spine after solid posterior spinal fusion. The condition has also been reported in the setting of newer, so-called growth-friendly posterior distraction-based spinal instrumentation. The clinical evidence of crankshaft phenomenon is often subtle, whereas radiographic findings are usually more apparent. However, objective measurement of radiographic signs may be complicated by instrumentation and postoperative changes. Treatment options for patients with the crankshaft phenomenon are limited; in those with problematic deformity and/or risk of progression, additional surgery may be indicated.

Orthobiologics in Pediatric Orthopedics.

Orthobiologics are biologic devices or products used in orthopedic surgery to augment or enhance bone formation. The use of orthobiologics in pediatric orthopedics is less frequent than in other orthopedic subspecialties, mainly due to the naturally abundant healing potential and bone formation in children compared with adults. However, orthobiologics are used in certain situations in pediatric orthopedics, particularly in spine and foot surgery. Other uses have been reported in conjunction with specific procedures involving the tibia and pelvis. The use of bioabsorable implants to stabilize children's fractures is an emerging concept but has limited supporting data.

Evaluation of Pediatric Questions on the Orthopaedic In-Training Examination-An Update.

BACKGROUND: Pediatric orthopaedics is tested frequently on the Orthopaedic In-Training Examination (OITE). The most recent data on the pediatrics section of the OITE were generated from content 10 years old. The purpose of this study is to assess the pediatric orthopaedic questions on the 2011 to 2014 OITE, and to compare question categories and cognitive taxonomy with previous data. METHODS: Four years (2011 to 2014) of OITE questions, answers, and references were reviewed. The number of pediatric questions per year was recorded, as well as presence of a clinical photo or imaging modality. Each question was categorized and assigned a cognitive taxonomy level. Categories included: knowledge; knowledge-treatment modalities; diagnosis; diagnosis/recognition of associated conditions; diagnosis/further studies; and diagnosis/treatment. Cognitive taxonomy levels included: simple recall, interpretation of data, and advanced problem-solving. RESULTS: The 3 most commonly covered topics were upper extremity trauma (17.4%), scoliosis (10.1%), and developmental dysplasia of the hip (5.7%). Compared with previous data, the percentage of pediatric questions was constant (13% vs. 14%). Categorically, the more recent OITE examinations contained significantly fewer questions testing simple knowledge (19% vs. 39%, P=0.0047), and significantly more questions testing knowledge of treatment modalities (17% vs. 9%, P=0.016) and diagnosis with associated conditions (19% vs. 9%, P=0.0034). Regarding cognitive taxonomy, there was a significant increase in the average number of questions that required advanced problem-solving (57% vs. 46%, P=0.048). Significantly more questions utilized clinical photographs and imaging studies (62% vs. 48%, P=0.012). The most common reference materials provided to support correct responses included Lovell and Winter's Pediatric Orthopaedics (25.7%) and the Journal of Pediatric Orthopaedics (23.4%). CONCLUSIONS: Although the percentage of pediatric questions on the OITE has remained essentially constant, the percentage of questions requiring advanced problem-solving or interpretation of images has increased significantly in the past 10 years. Knowledge of question type and content may be helpful for those involved in resident education and in the development of didactic pediatric orthopaedic curricula. LEVEL OF EVIDENCE: Level IV.

Mechanical failure of single cannulated screw fixation of unstable slipped capital femoral epiphysis.

UNLABELLED: Slipped capital femoral epiphysis (SCFE) is a common hip condition in adolescents, most commonly treated with in-situ cannulated screw fixation. We report two cases of cannulated screw failure within the femoral neck following SCFE fixation. To our knowledge, this is the first reported case in the literature of cannulated screw failure within the femoral neck following in-situ screw fixation for unstable SCFE. LEVEL OF EVIDENCE: Level IV.

Validity of Estimates of Intraoperative Blood Loss in Pediatric Spinal Deformity Surgery.

INTRODUCTION: Intraoperative blood loss is a significant concern in pediatric spinal deformity surgery, and numerous reports exist in the literature regarding this issue. Multiple interventions are used to minimize intraoperative blood loss and subsequent need for blood product replacement during and after these procedures. However, a basic question remains regarding the overall accuracy of intraoperative blood loss measurements used to generate these studies. MATERIALS AND METHODS: We performed an institutional review board-approved study that compared estimated blood loss (EBL) by the anesthesia provider and surgeon after the completion of surgery for pediatric spinal deformity by a single surgeon. We used the estimate by the anesthesia provider that was to be part of the anesthesia record. The surgeon's estimate was generated based on a formula employing the volume of blood products processed by a Cell-Saver device and available for reinfusion. RESULTS: We collected data from 51 patients. The mean EBL (surgeon) was 795.84 mL and mean EBL (anesthesia) was 669.30 mL. The mean percent estimated blood volume loss (%EBVL) (surgeon) was 22.9% and mean %EBVL (anesthesia) was 19.8%. Student t-test analysis demonstrated statistical significance between both sets of values (EBL, p = .010; %EBVL, p = .010). CONCLUSIONS: There was a statistically significant difference in EBL values for this patient sample between the anesthesiologist and orthopedic surgeon; the surgeon's estimates were significantly higher. This difference may be important in interpreting existing studies regarding interventions used to minimize surgical blood loss. In addition, this lack of agreement highlights the need for authors to be more accurate and consistent regarding the source of blood loss data in future clinical studies.

Two unusual presentations of focal fibrocartilaginous dysplasia.

Focal fibrocartilaginous dysplasia (FFCD) is an uncommon, yet well documented, cause of long-bone angular deformities in children. We report two unusual cases of FFCD involving the tibia: one within the proximal tibia inducing genu valgum and one apparent FFCD lesion of the distal tibia that generated a varus deformity of the distal tibia. To our knowledge, this is the first reported case of FFCD in the distal tibia. Each lesion led to an angular deformity that required surgical management.

Concurrent orthopedic and neurosurgical procedures in pediatric patients with spinal deformity.

The management of pediatric patients with complex spinal deformity often requires both an orthopedic and a neurosurgical intervention. The reasons for multiple subspecialty involvement include, but are not limited to, the presence of a tethered cord requiring release or a syrinx requiring decompression. It has been common practice to perform these procedures in a staged manner, although there is little evidence in the literature to support separate interventions. We reviewed a series of consecutive patients who underwent spinal deformity correction and a neurosurgical intervention concurrently in an attempt to assess the safety, efficacy, and possible complications associated with such an approach. Eleven patients were reviewed who underwent concurrent orthopedic and neurosurgical procedures. Data were collected for patient demographics, preoperative diagnosis, procedures performed, intraoperative and perioperative complications, as well as any unexpected return to the operating room for any reason. Operative notes and anesthesia records were reviewed to determine estimated blood loss, surgical time, and the use of intraoperative neurological monitoring. Patient diagnoses included myelodysplasia (N=6), congenital scoliosis and/or kyphosis (N=4), and scoliosis associated with Noonan syndrome (N=1). Age at the time of surgery averaged 9 years 2 months (range=14 months to 17 years 2 months). Estimated blood loss averaged 605 ml (range=50-3000 ml). The operative time averaged 313 min (range=157-477 min). There were no intraoperative complications, including incidental dural tears or deterioration in preoperative neurological status. One patient developed a sore associated with postoperative cast immobilization that led to a deep wound infection. It appears that concurrent orthopedic and neurosurgical procedures in pediatric patients with significant spinal deformities can be performed safely and with minimal intraoperative and postoperative complications when utilizing modern surgical and neuromonitoring techniques. Level of evidence=Level IV.

Sudden appearance of new upper extremity motor function while performing neurophysiologic intraoperative monitoring during tethered cord release: a case report.

UNLABELLED: : Tethered cord syndrome occurs when the distal spinal cord or filum adheres to adjacent structures resulting in progressive sensorimotor deficits in the lower extremities, fecal and/or urinary incontinence, and musculoskeletal deformities. Tethering of the distal cord may be idiopathic, may be associated with an intraspinal abnormality such as a lipoma, but most commonly the distal spinal cord remnant is adherent to the area of the original dysraphism repair in patients with myelodysplasia. Surgery to untether the cord is indicated in patients with worsening pain symptoms, progressive limb deformity or spasticity, or before any acute correction of an associated spinal deformity. Neurophysiologic intraoperative monitoring is used to minimize the risk of inadvertent nerve root or spinal cord injury during the untethering procedure and to assess any changes in cord function at the time of an associated spinal deformity correction. We present a patient with a lumbar level myelodysplasia, Chiari II malformation, severe scoliosis, and tethered cord that underwent concurrent scoliosis correction and tethered cord syndrome surgery, who demonstrated immediate intraoperative improvement in neurophysiologic responses in a previously flaccid upper extremity after untethering. These monitoring changes correlated with clinical improvements noted by physicians and family postoperatively. LEVEL OF EVIDENCE: Level IV.

Predicting scoliosis progression from skeletal maturity: a simplified classification during adolescence.

BACKGROUND: Both the Tanner-Whitehouse-III RUS score, which is based on the radiographic appearance of the epiphyses of the distal part of the radius, the distal part of the ulna, and small bones of the hand, and the digital skeletal age skeletal maturity scoring system, which is based on just the metacarpals and phalanges, correlate highly with the curve acceleration phase in girls with idiopathic scoliosis. However, these systems require an atlas and access to the scoring system, making their use impractical in a busy clinical setting. We sought to develop a simplified system that would correlate highly with scoliosis behavior but that would also be rapid and reliable for clinical practice. METHODS: A simplified staging system involving the use of the Tanner-Whitehouse-III descriptors was developed. It was tested for intraobserver and interobserver reliability by six individuals on thirty skeletal age radiographs. The system was compared with the timing of the curve acceleration phase in a cohort of twenty-two girls with idiopathic scoliosis. RESULTS: The average intraobserver unweighted kappa value was 0.88, and the average weighted kappa value was 0.96. The percentage of exact matches between readings for each rater was 89%, and 100% of the differences were within one unit. The average interobserver unweighted kappa value was 0.71, and the average weighted kappa value was 0.89. The percentage of exact matches between two reviewers was 71%, and 97% of the interobserver differences were within one stage or matched. The agreement was highest between the most experienced raters. Interobserver reliability was not improved by the use of a classification-specific atlas. The correlation of the staging system with the curve acceleration phase was 0.91. CONCLUSIONS: The simplified skeletal maturity scoring system is reliable and correlates more strongly with the behavior of idiopathic scoliosis than the Risser sign or Greulich and Pyle skeletal ages do. The system has a modest learning curve but is easily used in a clinical setting and, in conjunction with curve type and magnitude, appears to be strongly prognostic of future scoliosis curve behavior.

A previously unreported complication of the AO cannulated 4.0- and 4.5-mm screw systems: a review of three cases.

Cannulated screws are utilized widely in the management of periarticular fractures and osteotomies. Reports of complications related to these screws have increased as use has become more commonplace. A novel mode of mechanical failure of 4.0-mm and 4.5-mm A-O cannulated screws is described in three patients, as well as hypotheses regarding possible causes of the failure. It may be prudent to predrill and tap dense cortical bone when such devices are used in teenagers and young adults patients in an attempt to avoid similar damage to the screw during insertion.

Predictors of red cell transfusion in children and adolescents undergoing spinal fusion surgery.

STUDY DESIGN: A retrospective review was performed. OBJECTIVE: To determine clinical predictors of allogeneic and autologous red cell transfusion in children and adolescents undergoing spinal fusion surgery. SUMMARY OF BACKGROUND DATA: Blood loss during spinal fusion surgery often results in the need for transfusion therapy. Preoperative identification of patients at increased risk for red cell transfusion would allow more specific use of interventions designed to control excessive bleeding. METHODS: The medical records of all patients undergoing posterior spinal fusion surgery at a single institution between July 1, 1999 and June 30, 2001 were reviewed. Logistic and stepwise multiple regression analyses were used to identify predictors of allogeneic and autologous red cell transfusion during the operative and postoperative periods. RESULTS: Posterior spinal fusion surgery was performed in 107 patients (males, 42%) with a median age of 13.7 years (range, 1-20 years). The median intraoperative blood loss was 22 mL/kg (range, 4.4-72 mL/kg). Blood transfusion involved 63 patients (59%) who received 17 mL/kg (range, 3-65 mL/kg) of allogeneic packed red blood cells and 14 patients (13%) who received 7 mL/kg (range, 4-19 mL/kg) of autologous red cells donated before surgery. Underlying neuromuscular disease, lower body weight, and a higher number of vertebrae fused independently predicted a greater number of allogeneic red cells transfused (R2 = 0.53). The amount of autologous blood donated before surgery predicted the number of autologous red cells transfused (R2 = 0.56). CONCLUSIONS: Allogeneic red cell transfusion often is required for small patients with underlying neuromuscular disease who undergo extensive spinal fusion surgery. These patients may be less able to donate autologous blood before surgery. Newer therapies to reduce blood loss and transfusion requirement are needed most for this population.