Incidence and Risk Factors for Heterotopic Ossification in a Matched Cohort Adolescent Population Undergoing Hip Arthroscopy.

BACKGROUND: Heterotopic ossification (HO) is a known complication after hip arthroscopy in adults, positively associated with larger cam resection, male sex, older age, and obesity, and negatively associated with nonsteroidal anti-inflammatory drug (NSAID) use and capsular closure. However, it has not been well-documented in adolescents. The purpose of this study was to determine the incidence and risk factors for the development of HO in adolescent patients undergoing hip arthroscopy. METHODS: Clinical and operative records from a pediatric institution were queried to identify patients aged 21 years or younger who underwent hip arthroscopy between 2008 and 2018. The 27 cases that developed HO were matched 1:4 on age and sex with 107 controls. The bivariate analysis assessed the relationship between demographic and perioperative factors on the development of HO. Multivariable logistic regression evaluated the association between prophylactic NSAID use (indomethacin 75 mg, 3 wk) and HO, controlling for surgeon and extent of cam resection (change in alpha angle). RESULTS: Twenty-seven of 595 (4.5%) hips that underwent hip arthroscopy developed HO within 2 years of surgery. Prophylactic indomethacin was not significantly associated with developing HO [30% (8/27), P=0.83], after controlling for surgeon and extent of cam resection-nor were age, sex, and body mass index percentile. Of patients who developed HO, a smaller proportion underwent reoperation for HO excision among those who received prophylactic indomethacin than those who did not [13% (1/8) vs. 63% (12/19), P=0.03]. CONCLUSIONS: The incidence of HO within 2 years of hip arthroscopy in this adolescent population was 4.5%. Although studies in the adult hip arthroscopy population have pointed to a protective role of NSAIDs (eg, indomethacin) in radiographic HO, the effect was less certain in this adolescent sample. Larger studies are important to further evaluate the role of prophylactic NSAIDs and variations in arthroscopic technique in developing HO. LEVEL OF EVIDENCE: Level III-therapeutic, case-control study.

Elevated ESR/CRP Ratio Is Associated With Reinfection After Debridement, Antibiotics, and Implant Retention in Chronic Periprosthetic Joint Infections.

BACKGROUND: Ratios of established inflammatory markers, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), have been used for diagnostic purposes in the surgical field; however, the ESR:CRP ratio (ECR) has not been evaluated as a marker for predicting infection resolution in patients with periprosthetic joint infections (PJIs). This study aimed to evaluate the diagnostic accuracy of ECR in predicting postoperative reinfection in patients who underwent debridement, antibiotics, and implant retention (DAIR). METHODS: This is a retrospective review of 179 consecutive patients who underwent DAIR revision total joint arthroplasty for PJI. Patients were stratified by acuity of their infection: acute PJI, acute hematogenous PJI, and chronic PJI. The area under the receiver operating characteristic curve was calculated to evaluate ECR as diagnostic marker for predicting postoperative reinfection in patients who underwent DAIR. RESULTS: Statistically significant differences in ECR were found in patients who underwent DAIR revision total joint arthroplasty for chronic infection (1.23 vs 2.33; P = .04). There was no significant difference in ECR in patients who underwent DAIR for acute infection (P = .70) and acute hematogenous infection (P = .56). In patients who underwent DAIR for chronic PJI, ECR demonstrated a sensitivity and specificity of 75% and 84%, respectively, for the prediction of postoperative reinfection, which was significantly higher than that of ESR (sensitivity, 67%; specificity, 47%; P < .001) and CRP (sensitivity, 50%; specificity, 26%; P < .001). CONCLUSION: Elevated ECR was associated with an increased reinfection risk in patients who underwent DAIR for chronic PJI, suggesting that preoperative ECR may be a useful predictor to identify patients at increased risk of reinfection after DAIR for chronic PJIs.

Gross Motor Function Classification System Specific Growth Charts-Utility as a Risk Stratification Tool for Surgical Site Infection Following Spine Surgery.

BACKGROUND: There is currently minimal evidence that preoperative malnutrition increases surgical site infection (SSI) risk in children with cerebral palsy (CP) undergoing spinal deformity surgery. Growth charts specifically for patients with CP have been created to aid in the clinical interpretation of body mass index (BMI) as a marker of nutritional status, but to our knowledge these charts have never been used to risk stratify patients before orthopaedic surgery. We hypothesize that patients with CP who have BMI-for-age below the 10th percentile (BMI≤10) on CP-specific growth charts are at increased risk of surgical site infection following spinal deformity surgery compared with patients with BMI-for-age above the 10th percentile (BMI>10). METHODS: Single-center, retrospective review comparing the rate of SSI in patients with CP stratified by BMI-for-age percentiles on CP-specific growth charts who underwent spinal deformity surgery. Odds ratios with 95% confidence intervals and Pearson χ tests were used to analyze the association of the measured nutritional indicators with SSI. RESULTS: In total, 65 patients, who underwent 74 procedures, had complete follow-up data and were included in this analysis. Ten patients (15.4%) were GMFCS I-III and 55 (84.6%) were GMFCS IV-V; 39 (60%) were orally fed and 26 (40%) were tube-fed. The rate of SSI in this patient population was 13.5% with 10 SSIs reported within 90 days of surgery. There was a significant association between patients with a BMI below the 10th percentile on GMFCS-stratified growth charts and the development of SSI (OR, 13.6; 95% CI, 2.4-75.4; P=0.005). All SSIs occurred in patients that were GMFCS IV-V. There was no association between height, weight, feeding method, or pelvic instrumentation and development of SSI. CONCLUSIONS: CP-specific growth charts are useful tools for identifying patients at increased risk for SSI following spinal instrumentation procedures, whereas standard CDC growth charts are much less sensitive. There is a strong association between preoperative BMI percentile on GMFCS-stratified growth charts and SSI following spinal deformity surgery. LEVEL OF EVIDENCE: Level III-Retrospective Study.

Outcomes of lesser tuberosity osteotomy in revision anatomic shoulder arthroplasty.

BACKGROUND: Lesser tuberosity osteotomy (LTO) is a common surgical approach during anatomic shoulder arthroplasty. Outcomes of LTO have been shown to be similar to subscapularis tenotomy and peel techniques, but little is known about the outcomes of LTO during revision arthroplasty. METHODS: This retrospective case series included 10 consecutive patients who underwent LTO during revision shoulder arthroplasty at a single institution from 2012 to 2016. Patients underwent a preoperative computed tomography scan to evaluate the lesser tuberosity bone stock. Demographic information, radiographic evidence of LTO healing, outcomes of range of motion, subscapularis strength, and visual analog scale pain scores were analyzed. RESULTS: Revision total shoulder arthroplasty with LTO was performed for glenoid arthritis after hemiarthroplasty in 10 patients. Average age at surgery was 59.8 years, and no humeral stems were revised. Eight of 10 patients had prior subscapularis tenotomy. Average follow-up after revision surgery was 9.2 months. LTO union was documented in 80% and nondisplaced nonunion in 20%. At follow-up, 50% reported mild pain. Subscapularis strength testing was graded normal in 80% and weak in 20%. Average visual analog scale pain improved from 9.4 prerevision to 4.8 postrevision (P < .05). On average, range of motion improved in active forward elevation from 123° to 141° and remained unchanged in active external rotation from 42° to 42°. CONCLUSION: Patients undergoing LTO during revision anatomic shoulder arthroplasty demonstrate successful LTO bony healing, improvement in pain, and improved forward elevation. In select patients not requiring humeral stem revision, LTO is a safe and effective surgical approach to subscapularis management during revision anatomic shoulder arthroplasty.

Outcomes of Reverse Total Shoulder Arthroplasty for Proximal Humerus Fracture Versus Rotator Cuff Arthropathy.

INTRODUCTION: Reverse total shoulder arthroplasty (RSA) is used to treat a variety of shoulder-related pathologies. This study compared medium-term clinical outcomes of less than 10-year follow-up in patients treated with RSA for proximal humerus fracture (PHF) versus rotator cuff arthropathy (RCA). METHODS: This retrospective review was conducted at two tertiary care centers, in which self-reported clinical outcomes were assessed using four validated instruments, that is, American Shoulder and Elbow Society (ASES) score, Shoulder Pain and Disability Index (SPADI), visual analog scale (VAS), and shoulder subjective value (SSV). Statistical analyses were performed using linear or logistic regression with generalized estimating equations. RESULTS: Of the 189 patients included in this study, 70 were treated for fracture and 119 for RCA. At a mean postoperative follow-up of 6.4 years, the means were 79.7 for ASES score, 20.8 for SPADI-Total, 0.8 for VAS, and 77.1 for SSV. After adjusting models for covariates, there was no significant difference in average SSV (P = 0.7), VAS (P = 0.7) or SPADI-Pain (P = 0.2) between PHF and RCA cohorts; however, the RCA cohort reported significantly better outcomes in ASES scores (P = 0.002), SPADI-Disability (P < 0.0001), and SPADI-Total (P = 0.0001). DISCUSSION: Patients with RCA and PHF treated with RSA achieved similar medium-term outcomes in several domains, particularly postoperative pain levels; however, patients with PHF reported greater perceived disability. RSA is an effective pain-controlling procedure, but patients may have variable functional outcomes based on the indication for surgery.

Native Hip Septic Arthritis in the Setting of Postpartum Gynecologic Infection: A Case Report.

CASE: A 34-year-old healthy G3P3 woman, 1.5 weeks postpartum, presented with hip pain, fever, and a rash. Clinical examination, laboratory testing, and microbiologic cultures identified bacterial arthritis of the right hip; obstetric/gynecologic examination and cultures identified endometrial, vaginal, and urinary tract infections caused by the same pathogen, group A streptococcus, likely contracted from her 5-year-old son who had streptococcal pharyngitis. She underwent successful surgical decompression of the hip with concurrent medical management of toxic shock syndrome (TSS). CONCLUSIONS: Hematogenously spread septic arthritis may occur in the absence of positive blood cultures during the postpartum period, increasing the risk of developing TSS.

Hypodermic needle to guide Kirschner-wire placement in paediatric supracondylar humerus fractures: a technical trick.

PURPOSE: Supracondylar humerus fractures are among the most common injuries in the paediatric population, accounting for 16% of all paediatric fractures and roughly 60% to 70% of all paediatric elbow fractures. Typical treatment for displaced and unstable supracondylar humerus fractures is surgical intervention, often with percutaneous Kirschner-wire (K-wire) fixation. Timing of surgery is dependent on the patient's neurovascular status on presentation, with surgical emergencies being performed at all hours of day and night. Percutaneous fixation of paediatric elbow fractures can be challenging as a result of the propensity for the elbow to become quite swollen with these fractures, particularly in smaller and physiologically more immature elbows. METHODS: We have developed a simple operative technique to guide placement of percutaneous wires for supracondylar humerus fractures using a hypodermic needle as a reference marker. RESULTS: In our experience, trainees utilizing this technique demonstrate greater appreciation for start point and trajectory of wires during percutaneous pinning, with better communication amongst surgical team members about necessary adjustment for optimal placement of K-wires. CONCLUSION: Utilization of this technique has the potential to refine surgical technique by minimizing errant wire passes, radiation and operative time when performing percutaneous pinning of reduced type III supracondylar humerus fractures. LEVEL OF EVIDENCE: V, Novel Surgical Technique.

Outcome of Spinal Versus General Anesthesia in Revision Total Hip Arthroplasty: A Propensity Score-Matched Cohort Analysis.

INTRODUCTION: Spinal anesthesia has been previously shown to offer improved patient outcomes compared with general anesthesia in revision total knee arthroplasty. This study aimed to evaluate the potential differences in perioperartive and postoperative outcomes in revision total hip arthroplasty (THA) between spinal or general anesthesia. METHODS: A total of 2,656 consecutive patients who underwent revision THA were evaluated. Propensity-score-adjusted multivariate logistic regression analyses were applied to control for intergroup variability and evaluate the differences in outcomes and complications with anesthesia type. RESULTS: Propensity score matching resulted in 1:1 matching with 265 patients in each anesthesia cohort. Multivariate analyses demonstrated that patients administered general anesthesia had a significantly longer procedure time (174.8 versus 161.3, P < 0.01), higher intraoperative (402.6 versus 305.5 mL, P < 0.01), and total perioperative blood loss (1802.2 versus 1,684.2 mL,P < 0.01). In addition, patients administered general anesthesia were found to have higher odds for two or more inhospital complications (odds ratio, 4.51, P < 0.01) and extended length of stay (odds ratio, 2.45, P = 0.02). DISCUSSION: Our study shows that propensity-matched patients who received spinal anesthesia for revision THA exhibited notable reduction in surgical time, perioperative blood loss, and complications compared with patients who received general anesthesia, suggesting that spinal anesthesia is a viable alternative to general anesthesia in revision THA.

Outpatient Shoulder Arthroplasty Patient Selection, Patient Experience, and Cost Analyses: A Systematic Review.

BACKGROUND: The utilization of outpatient shoulder arthroplasty has been increasing. With increasing pressure to reduce costs, further underscored by the coronavirus (COVID-19) pandemic, many health-care organizations will move toward outpatient interventions to conserve inpatient resources. Although abundant literature has shown the advantages of outpatient total hip arthroplasty (THA) and total knee arthroplasty (TKA), there is a relative paucity describing outpatient shoulder arthroplasty. Thus, the purpose of this study was to summarize the peer-reviewed literature of outpatient shoulder arthroplasty with particular attention to patient selection, patient outcomes, and cost benefits. METHODS: The PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Embase databases were queried according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. All articles on outpatient shoulder arthroplasty were included. Data on patient selection, patient outcomes, and cost analyses were recorded. Patient outcomes, including complications, reoperations, and readmissions, were analyzed by weighted average. RESULTS: Twenty-three articles were included for analysis. There were 3 review articles and 20 studies with Level-III or IV evidence as assessed per The Journal of Bone & Joint Surgery Level of Evidence criteria. Patient selection was most often predicated on age <70 years, body mass index (BMI) <35 kg/m2, absence of active cardiopulmonary comorbidities, and presence of home support. Complications and readmissions were not common and either improved or were equivalent to those of inpatient shoulder arthroplasty. Patient satisfaction was high in studies of short-term and intermediate-term follow-up. The proposed cost benefit ranged from $747 to $53,202 with outpatient shoulder arthroplasty. CONCLUSIONS: The published literature to date supports outpatient shoulder arthroplasty as an effective, safe, and cost-reducing intervention with proper patient selection. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Number of screws in the articular segment of distal humerus AO/OTA C-type fractures treated with open reduction internal fixation is associated with complication rate.

INTRODUCTION: Surgical treatment of distal humerus fractures can lead to numerous complications. Data suggest that the number of screws in the distal (articular) segment may be associated with complication rate. The purpose of this study is to evaluate the association between a number of screws in the distal segment and complication rate for surgical treatment of distal humerus fractures. We hypothesize that the number of screws in the articular segment of distal humerus AO/OTA C-type fractures treated with open reduction internal fixation (ORIF) will be inversely proportional to the complication rate. METHODS: We performed a single-center retrospective cohort study of 27 patients who underwent ORIF of distal humerus fractures C-type with at least six months of radiographic and clinical follow-up. Clinical outcomes including a range of motion, pain, revision surgery for stiffness and/or heterotopic ossification (HO), nonunion, and persistent ulnar nerve symptoms requiring revision neurolysis were recorded. RESULTS: In C-type fractures, the use of three or fewer articular screws was significantly associated with nonunion or loss of fixation (RR 17, p = 0.006). Nineteen of 36 (53%) patients experienced at least one complication. The surgical approach, plate configuration, age, and ulnar nerve treatment (none, in situ release, transposition) were not associated with the need for revision surgery. Men had a higher risk of requiring surgical contracture release due to improving post-operative stiffness (RR 12, p = 0.02). CONCLUSION: In this retrospective study, the use of three or fewer screws to fix articular fragments in AO type C fractures was a significant risk for nonunion or loss of fixation. Plate configuration and surgical approach did not correlate with outcomes. Men had higher rates of complications and required more frequent revision surgery compared to women.

Total Hip Arthroplasty to Treat Chronic Native Hip Obturator Dislocation: A Case Report.

CASE: A 37-year-old woman presented with a rare chronic dislocation of her native right hip where the head of the femur was incarcerated in the obturator foramen of her pelvis. After optimization of sociomedical factors, she underwent successful total hip arthroplasty. CONCLUSION: Total hip arthroplasty is a viable treatment option for the chronic incarcerated obturator hip dislocation.

Epidemiology and trends of adult ice hockey injuries presenting to United States emergency departments: A ten-year analysis from 2007-2016.

PURPOSE: The adult population is under-represented in existing ice hockey injury studies, despite the number of United States (US) adult ice hockey players increasing from 103,533 in 2007 to 180,400 in 2016 (74%). This study establishes trends in demographics, injury location, and injury type for adult ice hockey players (≥19 years old) in the United States. METHODS: The National Electronic Injury Surveillance System (NEISS) was queried for all ice hockey injuries from January 1, 2007 to December 31, 2016. Cases under age 19 were excluded. Each injury's narrative text field was reviewed to determine mechanism of injury. RESULTS: A total of 1,653 patients, representing an estimated 68,786 ice-hockey related injuries, presented to NEISS-participating US EDs. The most commonly injured body parts were the face (n = 12,432, 18.1%), head (n = 10,201, 14.8%), shoulder (n = 9,654, 14.0%) and ankle (n = 5,389, 7.8%). The most common diagnoses made were laceration (n = 18,153, 26.4%), strain/sprain (n = 12,202, 17.7%), fracture (n = 10,079, 14.7%), contusion (n = 9,283, 13.5%) and concussion (n = 4,794, 7.0%). The most common mechanisms of injury were falling (n = 11,786, 18.7%), puck contact (n = 10,544, 15.3%) and player contact (n = 9,449, 13.7%). Concussions increased from 46 in 2007 to 928 in 2016 (R2 = 0.8, ß = 0.9, p < 0.001). Females (n = 1,852, 32%) had a higher proportion of head injuries than males (n = 8,349, 13.3%) (IPR = 2.4, p < 0.0001). The 50+ year old cohort showed a significant increase in injuries during the study period (n = 146 vs. 982, R2 = 0.75, ß = 0.87, p = 0.001). CONCLUSIONS: Despite changing trends in age and sex-related demographics, the majority of injuries in this population may be preventable with adequate enforcement of protective gear use. Increased education amongst players, coaches, trainers, orthopaedic surgeons and primary care physicians should be encouraged to minimize injuries.

Feasibility of a cost-effective, video analysis software-based mobility protocol for objective spine kinematics and gait metrics: a proof of concept study.

The purpose of this study was to investigate the potential of a high-throughput, easily implemented, cost-effective, video analysis software-based mobility protocol to quantify spine kinematics. This prospective cohort study of clinical biomechanics implemented 2-dimensional (2D) image processing at a tertiary-care academic institution. Ten healthy, able-bodied volunteers were recruited for 2D videography of gait and functional motion. The reliability of a 2D video analysis software program for gait and range of motion metrics was evaluated over 2 independent experimental sessions, assessing for inter-trial, inter-session, and inter-rater reliability. Healthy volunteers were evaluated for simple forward and side bending, rotation, treadmill stride length, and more complex seated-to-standing tasks. Based on established intraclass correlation coefficients, results indicated that reliability was considered good to excellent for simple forward and side bending, rotation, stride length, and more complex sit-to-standing tasks. In conclusion, a cost-effective, 2D, video analysis software-based mobility protocol represents a feasible and clinically useful approach for objective spine kinematics and gait metrics. As the complication rate of operative management in the setting of spinal deformity is weighed against functional performance and quality of life measures, an objective analysis tool in combination with an appropriate protocol will aid in clinical assessments and lead to an increased evidence base for management options and decision algorithms.

Efficacy of tranexamic acid on surgical bleeding in spine surgery: a meta-analysis.

BACKGROUND CONTEXT: Spine surgery is usually associated with large amount of blood loss, necessitating blood transfusions. Blood loss-associated morbidity can be because of direct risks, such as hypotension and organ damage, or as a result of blood transfusions. The antifibrinolytic, tranexamic acid (TXA), is a lysine analog that inhibits activation of plasminogen and has shown to be beneficial in reducing surgical blood loss. PURPOSE: To consolidate the findings of randomized controlled trials (RCTs) investigating the use of TXA on surgical bleeding in spine surgery. STUDY DESIGN: A metaanalysis. STUDY SAMPLE: Randomized controlled trials investigating the effectiveness of intravenous TXA in reducing blood loss in spine surgery, compared with a placebo/no treatment group. METHODS: MEDLINE, Embase, Cochrane controlled trials register, and Google Scholar were used to identify RCTs published before January 2014 that examined the effectiveness of intravenous TXA on reduction of blood loss and blood transfusions, compared with a placebo/no treatment group in spine surgery. Metaanalysis was performed using RevMan 5. Weighted mean difference with 95% confidence intervals was used to summarize the findings across the trials for continuous outcomes. Dichotomous data were expressed as risk ratios with 95% confidence intervals. A p<.05 was considered statistically significant. RESULTS: Eleven RCTs were included for TXA (644 total patients). Tranexamic acid reduced intraoperative, postoperative, and total blood loss by an average of 219 mL ([-322, -116], p<.05), 119 mL ([-141, -98], p<.05), and 202 mL ([-299, -105], p<.05), respectively. Tranexamic acid led to a reduction in proportion of patients who received a blood transfusion (risk ratio 0.67 [0.54, 0.83], p<.05) relative to placebo. There was one myocardial infarction (MI) in the TXA group and one deep vein thrombosis (DVT) in placebo. CONCLUSIONS: Tranexamic acid reduces surgical bleeding and transfusion requirements in patients undergoing spine surgery. Tranexamic acid does not appear to be associated with an increased incidence of pulmonary embolism, DVT, or MI.

Gait stability improvement after fusion surgery for adolescent idiopathic scoliosis is influenced by corrective measures in coronal and sagittal planes.

To achieve optimal results after fusion for adolescent idiopathic scoliosis (AIS), radiographic parameters must be aligned with motion and performance. The effects of fusion on balance are poorly understood. Center of mass (COM) excursion and instantaneous interaction with center of pressure (COP) provides information about patients' balancing ability during gait. This study investigates the interaction between COM and COP (COM-COP) in AIS patients before and one year after spine fusion and determines what radiographic goals predict restoration of harmonious COM-COP. This was a prospective study that investigated sixteen adolescents with AIS curvature >30˚ requiring surgical correction. Clinical outcomes measures, X-rays, and 3D motion-capture gait analysis were collected. Sagittal and coronal COM and COP offsets and inclination angles were calculated from positional data. COM excursion was calculated as peak COM displacement based on mediolateral and vertical deviation from a line fitted to the patient's path. Radiographic parameters were measured to determine variables predictive of change in COM excursion. Post-operatively, average COM peak displacement decreased (42.6 to 13.1 mm, p=0.001) and COM peak vertical displacement remained unchanged (17.0 to 16.3 mm, p=0.472). COM-COP inclination angles reduced in the coronal, but not sagittal plane. Coronal lower extremity peak inclination angles reduced (8.8˚ to 7.5˚, p=0.025), correlating with C7 plumb-line offset (R=0.581, p=0.018). Thoracic Cobb, thoracic kyphosis, and C7 plumb-line were predictors of change in COM excursion. Mediolateral COM excursion post-surgery may reflect an attempt to reduce kinetic demands with improved spinal alignment. Although AIS correction has historically focused on the coronal plane, sagittal parameters may be more important for motion than previously theorized.

Revision Surgery After 3-Column Osteotomy in 335 Patients With Adult Spinal Deformity: Intercenter Variability and Risk Factors.

STUDY DESIGN: Multicenter, retrospective review. OBJECTIVE: To assess rates, site variability, and risk factors for revision surgery (RS) after 3-column osteotomy (3CO). SUMMARY OF BACKGROUND DATA: Complex spinal osteotomies, including 3CO, are being increasingly performed in the setting of patients with adult spinal deformity with sagittal plane deformity. Three-column osteotomy procedures are associated with high complication and RS rates, but risk factors for complications and variability across centers for revision have not been well defined. METHODS: The incidence and indications for RS in 335 patients with adult spinal deformity were analyzed. RS indications were classified as "mechanical" (MR: implant failure, pseudarthrosis, junctional failure, and loss/lack of correction) or "nonmechanical" (NMR: neurological deficit, infection, wound dehiscence, and stenosis). Risks factors for RS were analyzed using generalized linear models. RESULTS: Three-month and 1-year RS incidences were 12.3% and 17.6%, respectively. Single-level 3CO (n = 311) had lower RS rates than multilevel 3CO (n = 24, 15.8% vs. 41.7%, P = 0.001). The 16.7% rate for single-level lumbar 3CO included 11.4% for MR and 5.7% for NMR. For all RS, 50% of MR and 78.6% of NMR occurred within 3 months of the index surgery. There was significant variation in rates across sites (range = 6.3%-31.9%, P = 0.001), however low- and high-volume sites had similar rates (18.2% vs. 16.2%, P = 0.503). Patients with MR were more likely to be sagittally undercorrected at 3 months (sagittal vertical axis = 7 cm vs. 3.2 cm, P = 0.003). Patients with NMR had more caudal 3CO levels (L4 vs. L3, P = 0.014) and larger 3CO bone resections than patients who did not (34°vs. 24.5°, P = 0.003). CONCLUSION: Three-column osteotomy procedures for adult spinal deformity surgery can provide significant deformity correction and lead to marked improvement in function despite established complication and revision rates. This study shows that RS is associated with lower level osteotomy and higher residual sagittal vertical axis. There is significant variability in revision rates across sites independent of site volume, suggesting potential systems and practice variations that warrant further study. LEVEL OF EVIDENCE: 4.