Does Size Really Matter? Incidence of Periprosthetic Fractures After Femoral Osteotomy in Patients With Cerebral Palsy.

OBJECTIVE: Of children, 30% to 35% with cerebral palsy (CP) develop hip subluxation or dislocation and often require reconstructive hip surgery, including varus derotation osteotomy (VDRO). A recent literature review identified postoperative fractures as the most common complication (9.4%) of VDROs. This study aimed to assess risk factors for periprosthetic fracture after VDRO in children with CP. METHODS: A total of 347 patients (644 hips, 526 bilateral hips) with CP and hip subluxation or dislocation (129 females; mean age at index VDRO: 8.6 y, SD 3.4, range: 1.5 to 17.7; 2 Gross Motor Function Classification System (GMFCS) I, 35 GMFCS II, 39 GMFCS III, 119 GMFCS IV, 133 GMFCS V, 21 unavailable) were included in this retrospective, single-group intervention (VDRO) study at a tertiary referral center. Imaging and clinical documentation for patients age 18 years or younger at index surgery, treated with VDRO were reviewed to determine demographic data, GMFCS level, surgeon, type of hardware implanted, use of anticonvulsants and steroids, type of postoperative immobilization, presence of periprosthetic fractures, fracture location and mechanism, and time from surgery to fracture. Potential determinants of periprosthetic fractures were assessed using mixed effects logistic regression. RESULTS: Of 644 hips, 14 (2.2%, 95% CI: 1.3%, 3.6%) sustained a periprosthetic fracture, at a median of 2.1 years postoperatively (interquartile range: 4.6 y, range: 1.2 mo to 7.8 y). Patients with a fracture had a median age at index surgery of 7.3 years (interquartile range: 4.3, range: 2.8 to 17.8; 1 GMFCS II, 6 GMFCS IV, 7 GMFCS V). Periprosthetic fractures were not significantly related to age at index surgery ( P = 0.18), sex ( P = 0.30), body mass index percentile ( P = 0.87), surgery side ( P = 0.16), anticonvulsant use ( P = 0.35), type of postoperative immobilization ( P = 0.40), GMFCS level ( P = 0.31), or blade plate size ( P = 0.17). Only surgeon volume significantly related to periprosthetic fracture (odds ratio = 5.03, 95% CI: 1.53, 16.56, P = 0.008), with the highest-volume surgeon also using smaller blade plates ( P < 0.01). CONCLUSIONS: Periprosthetic fractures after VDRO surgery in children with CP are uncommon, and routine hardware removal appears unnecessary. The data suggest that the common dogma of putting in the largest blade plate possible to maximize fixation may increase the risk of periprosthetic fracture. Due to the overall low fracture rate, especially when contextualized relative to the risk of hardware removal, a reactive approach to hardware removal appears warranted. LEVEL OF EVIDENCE: Level III-retrospective study (targeting varus derotational osteotomies in children with cerebral palsy).

Ankle Mortise Instability in Multiple Hereditary Exostoses.

Ankle valgus is commonly reported in patients with multiple hereditary exostoses (MHE). We report the characteristics of mortise widening in MHE, its progression over time, and the resultant ankle pain and function at skeletal maturity. Mortise medial space (M), talocrural angle (TC), and tibiotalar angle (TT) measurements were collected on preoperative and last follow-up radiographs. Operative data and complications were recorded. American Orthopaedic Foot and Ankle Society (AOFAS) and short form-36 scores at skeletal maturity were collected. A total of 16 patients (19 ankles) had MHE and mortise widening. Thirteen patients had surgery. Preoperatively, no patient complained of instability. However, 11 ankles (57.9%) were painful and 15 (78.9%) were clinically in valgus. Patients underwent surgery at a mean age of 11.8 ± 2.2 y. Operative interventions included medial distal tibia hemiepiphysiodesis for the majority of patients. There were no statistically significant differences between pre and postoperative M, TC, TT angles. Operative patients showed an improved mean M (5.17 ± 1.17 to 4.63 ± 1.06 mm) and TT (8.71 ± 5.40° to 4.54 ±7.58°), however, neither angle reached normal values. TC representing fibular length-maintained measurements within normal limits (82.2 ± 5.3° to 84.8 ±5.8°). Questionnaires were obtained for 10 (52.6%) ankles. Mean age at questionnaires collection was 19.0 ± 3.6 y. Mean AOFAS score was 74.8 ± 17.6 out of 100. Patients scored 6.5 ± 4.1 out of 10 for alignment, 33.0 ± 6.7 out of 40 for pain, 35.3 ± 9.5 out of 50 for function. All short form-36 scores were above the national mean. Improvement of M and TT angles was modest. TC angle was within normal limits but showed an overall fibular shortening and decreased lateral buttress and potential for talar shift, as reflected in AOFAS score. The underwhelming amount of mortise widening correction achieved may not provide for a stable ankle joint.

Absence of Peroneus Tertius in Split Anterior Tibialis Tendon Transfer Surgery.

Split anterior tibialis tendon transfer is a common orthopedic surgical procedure for varus foot deformities. In the absence of the peroneus tertius, the peroneus brevis may be used in the transfer. Little is known about the prevalence of each transfer type. The goal of this study is to understand trends in tendon transfer for patients who undergo split anterior tibialis tendon transfer. Records of all patients who underwent tibialis anterior tendon split transfer at our institution between January 2004 and September 2020 were reviewed. After, 337 subjects who underwent tibialis anterior tendon split transfer were included. The peroneus tertius was absent in 33.2% (112/337) of subjects. Logistic regressions showed the odds of having a missing peroneus tertius were 66.9% lower for subjects with cerebral palsy and related etiologies (odds ratio [OR]: 0.331, 95% confidence interval [CI]: 0.21, 0.53), 47% lower for white subjects (OR: 0.53, 95% CI: 0.31, 0.91), and 59.1% lower for non-Hispanic subjects (OR: 0.409, 95% CI: 0.25, 0.66). The odds of a missing peroneus tertius tendon were 2.72 times higher for subjects who identified in the other racial category (95% CI: 1.65, 4.49), and 2.41 times greater for subjects who identified as Hispanic (95% CI: 1.51, 3.84). Patients who underwent the procedure who identified as Hispanic or members of other (non-White, -Black, -Asian) racial groups had an increased likelihood of having a missing peroneus tertius tendon. Patients who identified as white, having cerebral palsy or related etiologies, or non-Hispanic had a decreased risk of having a missing peroneus tertius tendon.

Is Radiographic Imaging Necessary for Identifying Late Developmental Dysplasia of the Hip in Breech Infants with Normal Ultrasounds?

Purpose. The goal of our study was to investigate the prevalence of late DDH cases in breech infants who had a normal screening hip ultrasound and subsequent follow-up hip x-ray imaging. Methods. Infants with a history of intrauterine breech position, normal hip ultrasound within 3-months of birth, and follow-up hip x-rays within 2-years were included. Acetabular indices were measured on a supine AP pelvis radiograph. Results. Fifty-six patients had breech presentation at birth, a normal hip ultrasound, and returned for radiographic evaluation within 2 years. Of those, 11/112 (10%) of hips had late DDH based on their radiographic images at 1 standard deviation greater than normative values from age-adjusted controls. No infants showed hip dysplasia at 2 standard deviations greater than normative values from age-adjusted controls. Conclusions. Our results support previous studies that follow up should be considered for infants with breech presentation and normal hip ultrasounds near birth. Level of evidence. II.

Effect of Static Alignment on Dynamic Knee Abduction Moments in Adolescent Athletes with Recent ACL Reconstruction.

PURPOSE: Dynamic limb valgus, particularly high knee abduction moments, is a known risk factor for anterior cruciate ligament (ACL) injury and may result from poor static anatomic limb alignment, faulty biomechanics, or a combination of both. The purpose of this study was to assess the influence of static lower extremity anatomic alignment and dynamic kinematic/kinetic measures on knee abduction moments during sidestep cutting in adolescent athletes with recent ACL reconstruction. METHODS: This retrospective study included 50 adolescents with recent unilateral ACL reconstruction (18/50 female, mean age = 15.8 yr, 7.6 months postsurgery). Frontal plane hip-to-ankle imaging was used to measure mechanical axis deviation and tibial-femoral angle. Three-dimensional motion capture provided lower extremity kinematics and kinetics during quiet standing and during the loading phase (initial contact to peak knee flexion) of an anticipated 45° sidestep cut. Imaging, static motion capture, and dynamic motion capture measures were investigated as potential predictors of average dynamic knee abduction moment using correlation and backward stepwise linear regression. RESULTS: Dynamic knee abduction moment was best predicted by a combination of younger age and dynamic measures: trunk lean toward the planting limb, knee abduction and external rotation, and ankle inversion. Although static measures were correlated with dynamic knee abduction moment in univariate analysis, no static/anatomic variables entered the model once the dynamic measures were included. CONCLUSION: Knee abduction moments during sidestep cutting were related to dynamic factors reflecting frontal and transverse plane motion. Static (anatomic) lower limb alignment did not influence knee abduction moments once these dynamic factors were considered. Knee abduction moments and ACL injury risk are therefore not dictated by anatomic alignment and can be altered through neuromuscular/biomechanical training.

Anterior distal femoral hemiepiphysiodesis with and without patellar tendon shortening for fixed knee flexion contractures in children with cerebral palsy.

PURPOSE: Surgery is often required for fixed knee flexion contractures in patients with neuromuscular conditions. Anterior distal femoral hemiepiphysiodesis (ADFH) is an alternative to distal femoral extension osteotomy (DFEO) in skeletally immature patients. ADFH is typically not accompanied by patellar tendon shortening surgery (PTS). Our purpose was to compare ADFH alone versus ADFH with PTS for treatment of fixed knee flexion contractures and crouched gait in children with cerebral palsy (CP). METHODS: Retrospective review of pre- and postoperative gait analysis data for children with CP who underwent ADFH alone, or ADFH with PTS. Data were analysed using linear mixed models to control for covariates. RESULTS: In total, 25 participants (42 limbs) were included, 17 male and eight female, mean age at surgery 12.9 (sd 1.9) years. Both groups experienced significant improvement in popliteal angle, knee extension range of motion (ROM) and knee extension in stance phase. Greater improvement was seen for all variables in the ADFH/PTS group, mainly due to greater popliteal angle and knee flexion during gait preoperatively in that group (p ≤ 0.02) rather than the procedure performed (p ≥ 0.19). There was no difference between groups postoperatively. Rate of contracture resolution was 0.5° to 1.0° per month, faster in larger contractures (p = 0.02). CONCLUSIONS: ADFH with and without PTS is effective in improving knee extension in skeletally immature patients with CP, correcting contractures at a rate of 0.5° to 1.0° per month. Combined ADFH and PTS surgery may be preferable in patients with larger contractures of up to 30° to 35°. LEVEL OF EVIDENCE: III.

Hip Dysplasia Is Not More Common in W-Sitters.

Parents are frequently cautioned by therapists, teachers, physicians, and online resources about potential negative effects of w-sitting in children (including hip dysplasia), despite lack of evidence. To examine relationships between w-sitting and hip dysplasia, a prospective cohort study was conducted of 104 patients (196 hips), aged 9.9 (standard deviation = 5.7) years, who underwent hip/pelvis radiography at a pediatric tertiary care center. Measures of hip dysplasia were taken from radiographs. Parents/patients completed a questionnaire regarding the patients' sitting habits. Associations between hip dysplasia and w-sitting were analyzed statistically. About 48/104 parents/patients (46%) reported current or past w-sitting: 11/104 (11%) current, preferred position; 23/104 (22%) current, nonpreferred position, 14/104 (13%) w-sat in past, and 56/104 (54%) never w-sat. There was no difference in measures of hip dysplasia (P > .12) or hip dysplasia frequency between w-sitters (9%) and non-w-sitters (10%; P = .81), or among w-sitting persistence groups (P = .26). W-sitting in children is not associated with hip dysplasia.

Four-in-one Extensor Realignment for the Treatment of Obligatory or Fixed, Lateral Patellar Instability in Skeletally Immature Knee.

BACKGROUND: Congenital (fixed) and obligatory (habitual) patellar dislocations in children are a complex clinical and surgical challenge. Numerous individual surgical techniques have been described. This study aims to assess results, patient satisfaction, and complications after a combined Roux-Goldthwait procedure, vastus medialis obliquus advancement, Galeazzi procedure, and extensive, lateral release (4-in-1 extensor realignment) in the skeletally immature knee with obligatory, or fixed lateral patellar instability. METHODS: Records of children with congenital fixed or obligatory patellar instability, who underwent the 4-in-1 procedure at a single institution, were reviewed. Clinical results included ability and time for the return to activities of daily living (ADL) and sport, recurrent instability and/or dislocation, and necessity of long-term bracing. Continued pain was assessed by the Kujala Score. Complications including infection, recurrent instability, and the necessity for secondary procedures were recorded. RESULTS: A total of 34 patients (46 knees) mean age 10.3±2.4 years, underwent the 4-in-1 procedure with a mean postoperative follow-up of 51.6±31.5 (range, 12 to 146) months. Sixteen patients (22 knees) responded to a phone interview and questionnaire. All 16 patients returned to ADL in a mean time of 10.3±2.4 weeks. Ninety-one percent returned to sport in a mean time of 23.1±15.5 weeks. Long-term bracing was required for 6 knees after the surgery. The mean Kujala Score was 93.0±5.2 (range, 83 to 100). Complications included 6 of 34 patients (18%) with recurrent instability at the latest follow-up and 2 with superficial wound infection. CONCLUSIONS: Patients with obligatory or fixed lateral, patellar instability who undergo the 4-in-1 procedure have good short-term results with low complication rates. Return to ADL and sporting activity with minimal pain can be expected, usually without the need for long-term bracing. The 4-in-1 procedure is a viable option for skeletally immature patients with obligatory or fixed, lateral patellar instability. LEVEL OF EVIDENCE: Level IV-Therapeutic study.

Femoral shaft fractures in children with non-ambulatory neuromuscular disorders can be effectively treated using flexible intramedullary nails.

PURPOSE: There is little information in the literature regarding flexible intramedullary nails (FIN) for treating femur fractures in children with neuromuscular disorders. The purpose of this study is to investigate the outcomes of FIN for femoral shaft fractures in non-ambulatory children with neuromuscular disorders. METHODS: A retrospective review was conducted on patients with femur fractures at a paediatric hospital between 2004 and 2018. Inclusion criteria were femoral shaft fracture treated with FIN. Outcomes were compared between patients with neuromuscular disorders (NM group) and a control group of those without neuromuscular disorders. RESULTS: A total of 37 patients with 37 femoral shaft fractures were studied (12 patients in the NM group and 25 in the control group). All NM group patients were non-ambulatory at baseline. Fractures were length stable in all 25 patients in the control group and in 2/12 (17%) patients in the NM group. All fractures healed in both groups. Three complications (all nail migrations) requiring reoperation before fracture union occurred in the NM group, yielding a major complication rate of 25% (3/12) in the NM group versus 0% (0/25) in controls (p = 0.03). Angular deformity occurred in 5/12 (42%) NM group patients and 1/25 (4%) control group patient (p = 0.009); none required reoperation. CONCLUSION: Femur fractures in non-ambulatory children with neuromuscular disorders can be successfully treated with FIN. Angular deformities are common in this population, but had no functional impact in the non-ambulatory NM group patients. Surgeons must also be vigilant for implant prominence and skin breakdown in these patients. LEVEL OF EVIDENCE: III.

Closed vs open reduction in developmental dysplasia of the hip: The short-term effect on acetabular remodeling.

BACKGROUND: This study aims to assess acetabular remodeling following closed vs, open hip reduction in children younger than 2 years of age. METHODS: Records of children with DDH, who underwent closed or open reduction, were reviewed. Acetabular index (AI) was measured on radiographs taken prior to reduction and on outcome radiographs taken at age 4 years. Radiographic outcomes were analyzed and residual dysplasia (outcome AI ≥ 30) degrees recorded. RESULTS: 42 hips had closed reduction; and 26 hips had open reduction. A higher percentage of hips treated with successful closed reduction, had outcome AI ≥ 30° (29% vs. 19% p = 0.387). Residual dysplasia was more common in IHDI-IV hips than IHDI-III hips for both groups. A higher incidence of AVN was seen in the open reduction group (13% vs. 7%; p = 0.43). CONCLUSION: In children with DDH under the age of two, open reduction with capsulorrhaphy may benefit acetabular remodeling more so than closed reduction despite maintenance of reduction. Although AVN remains a risk, higher remodeling might be expected with open reduction.

Do seizures compromise correction maintenance after spinal fusion in cerebral palsy scoliosis?

Seizure disorder in cerebral palsy (CP) has been described as a risk factor for postoperative complications after posterior spinal fusion. However, the effect of seizures on the maintenance of curve correction has not been reported. The aim of this study is to investigate associations between seizure history and maintenance of curve correction after posterior spinal fusion in children with CP. We analyzed records of 201 children with CP who underwent posterior spinal fusion with two-year follow-up. Patients were classified as having no seizures (31%); controlled seizures (54%); or poorly controlled seizures (PCS, 15%). Perioperative data, radiographic measurements, and complications were compared between groups. Groups were similar in operative time, estimated blood loss, and rates of deep wound infection and implant-related complications. The PCS group had a higher rate of respiratory complications (27%) than the no seizures (10%; P = 0.03) and controlled seizures (12%; P = 0.04) groups. Controlled seizures and PCS groups had longer ICU stays than the no seizures group (P= 0.02 and P= 0.04). Major coronal curve and pelvic obliquity were corrected significantly in all groups, and correction was maintained at 2 years. Loss of correction during follow-up was similar between groups. Although seizures were associated with longer ICU stays and more respiratory complications, there was no association between seizure history and loss of curve correction at two years of follow-up after CP scoliosis surgery.

Split Tibialis Anterior Tendon Transfer to The Peroneus Brevis or Tertius for the Treatment of Varus Foot Deformities in Children with Static Encephalopathy: A retrospective case series.

INTRODUCTION: The study purpose was to determine the safety/efficacy of a split anterior tibialis tendon transfer (SPLATT) to the peroneus tertius or brevis in children with static encephalopathy and varus feet. METHODS: A retrospective review of short- and long-term complications, change in ankle range of motion, strength, and gait kinematics. Predictors of postoperative varus or valgus were examined. RESULTS: One hundred thirty-three patients were included (average age [SD] 10.3 [3.7]), with an average follow-up of 3.9 (3.4) years. Forefoot/hindfoot eversion range of motion improved (P ≤ 0.05), dorsiflexor strength was maintained or improved in 76.9% of patients, and dorsiflexion in swing phase was maintained. Complications occurred in 6 of 133 patients (4.5%) and included 1 transfer failure, 1 wound dehiscence, and four pressure areas from casts. Successful correction was achieved in 77% of patients. Later onset of recurrent varus (14.4%, 10.6% requiring revision surgery) and pes valgus (8.7%, 4.8% requiring revision surgery) occurred. The length of the follow-up predicted the development of the pes valgus (odds ratio 1.28, 95% CI 1.0 to 1.6). DISCUSSION: SPLATT to the peroneus tertius or brevis is effective, and complications are rare. Subsequent valgus or recurrent varus deformities may occur, possibly requiring repeat surgery.

Titanium Elastic Nails Are a Safe and Effective Treatment for Length Unstable Pediatric Femur Fractures.

BACKGROUND: Controversy exists regarding the treatment of length unstable pediatric femoral shaft fractures. The purpose of this study was to investigate the outcomes of skeletally immature children with length unstable femur fractures treated with titanium elastic nails (TENs). METHODS: A retrospective review was conducted on all patients with femoral shaft fractures at a tertiary care pediatric hospital from April 2006 to January 2018. Patients with femoral shaft fractures treated with TEN and minimum 6 months follow-up were included. Exclusion criteria were age 11 years or above, weight >50 kg, pathologic fracture, and neuromuscular disorders. Femur fractures were categorized into 2 groups: length unstable (spiral, comminuted, or long oblique fractures) versus length stable (transverse and short oblique). Complications and reoperations were compared between the groups. RESULTS: A total of 57 patients with 58 femoral shaft fractures were included. The mean age was 5±2 (1 to 11) years and mean follow-up was 20.4±18.1 (6.0 to 81.2) months. The mean weight was 22.9±7.7 (11.0 to 40.5) kg. There was no difference in age (P=0.32), weight (P=0.28) or follow-up length (P=0.57) between patients with length unstable fractures and those with length stable fractures. A total of 32/58 (55%) fractures were length unstable and 26/58 (45%) were length stable. Mean time to union was 4.6 months, and there was no significant difference in mean time to union between the 2 groups (P=0.71). Thirty-one complications occurred in 27 patients. There was no difference between groups in the incidence of major complications requiring revision surgery (P=0.68) and minor complications that did not require revision surgery (P>0.99). CONCLUSIONS: In children with femoral shaft fractures treated with TEN, there was no difference in the incidence of complications or reoperations between those with length unstable fractures and those with length stable fractures. TEN are a safe and effective choice for operative fixation of length unstable femoral shaft fractures in children. LEVEL OF EVIDENCE: Level III-retrospective comparative study.

Occiput-to-Pelvis Spinal Arthrodesis: A Case Series.

STUDY DESIGN: Retrospective case series. OBJECTIVES: To describe the indications, operative course, and outcomes in eight pediatric patients who underwent occiput-to-pelvis (O-P) spinal arthrodesis. SUMMARY: Spinal arthrodesis from the occiput to pelvis is needed for some children with extensive spine deformity. There are few reports of patients with O-P arthrodesis. METHODS: We reviewed records of pediatric patients who underwent spinal arthrodesis to treat spine deformity between 1987 and 2017 at one institution. Eight patients (six girls) who underwent staged O-P arthrodesis were identified. Underlying conditions, indications for surgery, medical comorbidities, operative courses, complications, and imaging of these patients were recorded. RESULTS: Diagnoses were neuromuscular disorders in five patients and syndromic disorders in three patients. Mean ages were 9.7 ± 4.1 years at index surgery and 16.8 ± 4.6 years at completion of O-P arthrodesis. Patients underwent a mean of three operations (range, two to five). Occipitocervical arthrodesis was the final operation in six of eight patients (all but the two patients with Loeys-Dietz syndrome). Mean follow-up after the last procedure was 8.5 ± 7.1 years. Two patients underwent revision for protruding occipital implants, and one patient underwent revision for thoracic pseudarthrosis. No patients developed postoperative infections or new neurologic deficits. At final follow-up, Scoliosis Research Society-22r questionnaire scores were lowest for Function (2.6 ± 1.0 of 5 possible points) and highest for Satisfaction (4.1 ± 1.4). CONCLUSIONS: O-P arthrodesis can benefit patients with extensive spine deformity from neuromuscular or syndromic causes. Patients were young at first operation, which may suggest that younger patients are at higher risk than older patients of major progression of deformity in other spinal regions after deformity correction. Health-related quality of life and radiographic outcomes suggest that patients who underwent O-P arthrodesis had satisfactory outcomes and maintenance of correction during a mean of 8.5 years of follow-up. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Deep Infections After Pediatric Spinal Arthrodesis: Differences Exist with Idiopathic, Neuromuscular, or Genetic and Syndromic Cause of Deformity.

BACKGROUND: Little is known about the rates, timing, and causative microorganisms of deep surgical site infections after spinal arthrodesis in patients with genetic and syndromic scoliosis compared with patients with adolescent idiopathic scoliosis and kyphosis or patients with neuromuscular scoliosis. METHODS: We reviewed data from 1,353 patients who were <21 years of age and had undergone spinal arthrodesis for deformity correction by 1 surgeon from 2000 to 2015. Deformity causes were genetic, idiopathic, or neuromuscular. We identified patients who had undergone an unplanned surgical procedure for a deep surgical site infection that was early (≤90 days after the procedure) or late (>90 days after the procedure). We compared deep surgical site infection rates, timing, and causative microorganisms by deformity cause. RESULTS: Deep surgical site infections occurred in 65 patients (4.8%): 4.2% for patients with genetic and syndromic scoliosis, 2.7% for patients with adolescent idiopathic scoliosis and kyphosis, and 10.0% for patients with neuromuscular scoliosis. Of the deep surgical site infections, 26 (40%) occurred early and 39 (60%) occurred late. The median times to deep surgical site infection onset were 51 days (range, 7 days to 7 years) in patients with genetic and syndromic scoliosis, 827 days (range, 10 days to 12 years) in patients with adolescent idiopathic scoliosis and kyphosis, and 45 days (range, 13 days to 6 years) in patients with neuromuscular scoliosis. Seventy-six microorganisms (41 gram-positive and 35 gram-negative) were isolated from 47 children with positive cultures; the most common was coagulase-negative Staphylococcus (n = 13). The ratio of gram-positive to gram-negative microorganisms was highest in patients with adolescent idiopathic scoliosis and kyphosis (4:1) and lowest in patients with genetic and syndromic scoliosis (0.5:1). In genetic and syndromic scoliosis, both early and late deep surgical site infections were more frequently caused by gram-negative bacteria. In neuromuscular scoliosis, early deep surgical site infections were more frequently caused by gram-negative bacteria, and late deep surgical site infections were more frequently caused by gram-positive bacteria. In adolescent idiopathic scoliosis and kyphosis, both early and late deep surgical site infections were more commonly caused by gram-positive bacteria. Methicillin-resistant Staphylococcus aureus was identified in 2 late deep surgical site infections in patients with neuromuscular scoliosis. CONCLUSIONS: Deep surgical site infections were more common in genetic and syndromic scoliosis than in adolescent idiopathic scoliosis and kyphosis, but less common than in neuromuscular scoliosis. Adolescent idiopathic scoliosis and kyphosis had the highest ratio of late to early deep surgical site infections. Patients with genetic and syndromic scoliosis had predominantly gram-negative microorganisms, particularly in early deep surgical site infections. Methicillin-resistant S. aureus infection was rare, occurring in only 2 patients with neuromuscular scoliosis. Gram-negative and gram-positive prophylactic antibiotics may be indicated for patients with genetic and syndromic scoliosis after spinal arthrodesis. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.