Role of Robotics in Adult Spinal Deformity.

Robotic-assisted adult deformity surgery has played a rapidly expanding role since its introduction. As robotic spine technologies improve, the potential to limit complications and morbidity is vast. The improvements in instrumentation accuracy combined with the ability to maintain that accuracy in multiple positions allow creative surgical approaches and techniques that can limit operative time, blood loss, and improve outcomes. In the years to come, robotic-assisted spine surgery and navigation will likely play an expanding role that continues to be defined. LEVEL OF EVIDENCE: 5, expert opinion.

Comparative Studies in the Shoulder Literature Lack Statistical Robustness: A Fragility Analysis.

PURPOSE: Evidenced-based decision-making is rooted in comparative clinical studies; however, a small number of outcome event reversals have the potential to change study significance. The purpose of this study was to determine the utility of applying fragility analysis to comparative studies in the published orthopaedic shoulder literature. METHODS: Comparative clinical shoulder research studies reporting 1:1 dichotomous categorical data were analyzed in 6 leading orthopaedic journals between 2006 and 2016. Statistical significance was defined as a P value of less than .05. The fragility index (FI) for each study outcome was determined by the number of event reversals required to change the P value to either greater or less than 0.05, thus changing the study conclusions. The associated fragility quotient (FQ) was determined by dividing the FI by the total population comprising a particular outcome. RESULTS: Of the 23,897 studies screened, 3,591 met search criteria, with 198 comparative studies ultimately included for analysis, 67 of which were randomized controlled trials. There were 357 total outcome events with 74 reported as significant and 283 as not significant. The FI was 4 (IQR 2-6) with an associated FQ of 0.066 (interquartile range [IQR] 0.038-0.102). There was no difference in statistical fragility between randomized and nonrandomized trials with both revealing a FI of 4 and FQ of 0.068 (IQR 0.044-0.107) and 0.065 (IQR 0.031-0.101), respectively. CONCLUSIONS: This current analysis reveals that comparative shoulder studies published in six leading orthopaedic journals are at risk of statistical fragility. As such, contemporary clinical shoulder literature may not be as robust as traditionally perceived with the reversal of only a few outcome events required to change study significance. Therefore, we advocate the reporting of both FI and FQ in addition to the P value as statistical complements to all comparative investigations to provide a more comprehensive understanding of trial stability and significance in the published shoulder literature. CLINICAL RELEVANCE: Comparative study designs are commonly employed in shoulder research. Several studies in both the general medical and orthopaedic literature have identified a lack of statistical robustness through comprehensive fragility analysis. Our findings demonstrate the P value may be an inadequate independent statistical metric requiring the complement of a FI and FQ to aid in the interpretation and understanding of study significance for clinical decision-making.

The Prognostic Value of Laboratory Markers and Ambulatory Function at Presentation for Post-Treatment Morbidity and Mortality Following Epidural Abscess.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To develop a comprehensive understanding of the prognostic value of laboratory markers on morbidity and mortality following epidural abscess. SUMMARY OF BACKGROUND DATA: Spinal epidural abscess is a serious medical condition with high rates of morbidity. The value of laboratory data in forecasting morbidity and mortality after epidural abscess remains underexplored. METHODS: We obtained clinical data on patients treated for epidural abscess at two academic centers from 2005 to 2017. Our primary outcome was the development of one or more complications within 90-days of presentation, with mortality a secondary measure. Primary predictors included serum albumin, serum creatinine, platelet-lymphocyte ratio, and ambulatory status at presentation. We used multivariable logistic regression techniques to adjust for confounders. The most parsimonious set of variables influencing both complications and mortality were considered to be clinically significant. These were then examined individually and in combination to assess for synergy along with model-discrimination and calibration. We performed internal validation with a bootstrap procedure using sampling with replacement. RESULTS: We included 449 patients in this analysis. Complications were encountered in 164 cases (37%). Mortality within 1-year occurred in 39 patients (9%). Regression testing determined that serum albumin, serum creatinine, and ambulatory status at presentation were clinically important predictors of outcome, with albumin more than 3.5 g/dL, creatinine less than or equal to 1.2 mg/dL, and independent ambulatory function at presentation considered favorable characteristics. Patients with no favorable findings had increased likelihood of 90-day complications (odds ratio [OR] 5.43; 95% confidence intervals [CI] 1.98, 14.93) and 1-year mortality (OR 8.94; 95% CI 2.03, 39.37). Those with one favorable characteristic had greater odds of complications (OR 4.00; 95% CI 2.05, 7.81) and mortality (OR 5.71; 95% CI 1.60, 20.43). CONCLUSION: We developed a nomogram incorporating clinical and laboratory values to prognosticate outcomes after treatment for epidural abscess. The results can be used in shared-decision making and counseling. LEVEL OF EVIDENCE: 3.

Implant Removal Matrix for the upper Extremity Orthopedic Surgeon.

Orthopedic implant removal is a commonly performed procedure. While implant removal can be associated with improved symptoms, risks of the surgery are notable. Stripped screws, broken and retained hardware, and morbidity associated with soft tissue compromise during difficult removal are all common. Familiarity with the instruments is critical to procedure success. The purpose of this study is to assist removal of unfamiliar screws in upper extremity surgery by offering a reference for screw and driver compatibility across manufacturers. Inclusion of device manufacturers was determined by market share. Screw size, drive configuration, and screw removal system compatibility data was collected and recorded. Screw, guide-wire, and screwdriver compatibility was assessed and compared to two commonly utilized universal implant-removal sets. Eight upper extremity implant vendors were included. The data was compiled in table format according to manufacturer and sub-categorized to facilitate screw identification according to radiographically identifiable characteristics. The diversity of orthopaedic implants in upper extremity surgery requires careful preoperative planning to identify the appropriate equipment for implant removal. The goal of this work is to provide a centralized reference of commonly implanted screws, guide-wires, and drivers for the upper extremity to facilitate removal.

Does Surgical Approach Influence the Risk of Postoperative Infection After Surgical Treatment of Tibial Pilon Fractures?

OBJECTIVES: To determine whether a particular surgical approach or combination of approaches is a risk factor for infection. DESIGN: Retrospective review. SETTING: Two Level-1 trauma centers. PATIENTS/PARTICIPANTS: Five hundred ninety pilon fractures in 581 patients (66% male) with a median age of 45 years were identified. INTERVENTION: Open reduction internal fixation of pilon fractures. MAIN OUTCOME MEASURES: Postoperative deep surgical site infection and risk factors for postoperative deep infection. RESULTS: The most common primary surgical approach was medial (54%), followed by anterolateral (25%), anteromedial (11%), posterolateral (8%), and posteromedial (2%). A dual approach to the distal tibia was used in 18% of the cases. The overall deep infection rate was 19%. There was no association between primary surgical approach and development of infection (P = 0.19-0.78). Independent risk factors for infection were smoking (hazard ratio, 2.1; P < 0.001) and need for soft tissue coverage (hazard ratio, 6.9; P < 0.001). CONCLUSIONS: Surgical approach does not appear to be a significant risk factor for postoperative infection after open reduction internal fixation of distal tibial pilon fractures. When treating tibial plafond fractures, surgeons should select the approach they feel best addresses the specific fracture pattern. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Severe aortic stenosis is associated with perioperative mortality in proximal femur fracture patients.

OBJECTIVES: Evaluate the correlation between aortic stenosis and perioperative mortality in patients following surgical fixation of proximal femur fractures. DESIGN: Retrospectively reviewed case series. SETTING: Two Academic, Level 1 Trauma Centers. PATIENTS/PARTICIPANTS: One hundred fifty-eight patients, definitively diagnosed with aortic stenosis by means of echocardiogram, who underwent surgical fixation for an isolated proximal femur fracture (OTA/AO 31-A, 31-B, 32-A, 32-B, and 32-C fractures) between January 2000 and June 2015. The severity of the aortic stenosis was based upon accepted echocardiographic hemodynamic parameters designated by the 2014 American Heart Association guidelines. MAIN OUTCOME MEASURES: Post Injury mortality, 30-day mortality, and 1-year mortality. SECONDARY OUTCOME MEASURES: Postoperative mortality stratified by severity of aortic stenosis based on aortic valve area (AVA) and ejection fracture (EF) as determined by preoperative echocardiography. RESULTS: One hundred fifty-eight patients were available for final analysis. Kaplan-Meier survival analysis revealed a significantly longer time to mortality among Non-severe aortic stenosis patients compared to Severe aortic stenosis patients, P value .006. Twenty-three percent of patients with Severe aortic stenosis and 10% of patients with Non-severe aortic stenosis died within 30 days of surgery. No significant difference was observed in mean survival among AS patients who underwent surgery within 48 hours of injury (34.5 months) and those delayed more than 48 hours after injury (25.0 months), P value .116. Among the commonly measured hemodynamic parameters of aortic stenosis, only AVA and EF were significantly associated with mortality, P value .015, and P value < .001, respectively. There were no significant effects for Aortic Vmax, Peak ΔP, and Mean ΔP. An AVA of 0.8 cm2 or less is associated with a significantly shorter (22 months) postinjury mortality than patients with an AVA > 0.8 cm2. (37 months), P value .009. CONCLUSIONS: Severe aortic stenosis is associated with a shorter postoperative time to mortality after surgical fixation of hip fractures compared to patients with Non-severe stenosis. Aortic valve area and Ejection Fraction are the only hemodynamic parameters significantly associated with postoperative mortality.Level of Evidence: Prognostic Level III.

Syndesmotic Fixation Utilizing a Novel Screw: A Retrospective Case Series Reporting Early Clinical and Radiographic Outcomes.

Background. Syndesmotic disruption occurs in 20% of ankle fractures and requires anatomical reduction and stabilization to maximize outcomes. Although screw breakage is often asymptomatic, the breakage location can be unpredictable and result in painful bony erosion. The purpose of this investigation is to report early clinical and radiographic outcomes of patients who underwent syndesmotic fixation using a novel metal screw designed with a controlled break point. Methods. We performed a retrospective review of all patients who underwent syndesmotic fixation utilizing the R3lease Tissue Stabilization System (Paragon 28, Denver, CO) over a 12-month period. Demographic and screw-specific data were obtained. Postoperative radiographs were reviewed, and radiographic parameters were measured. Screw loosening or breakage was documented. Results. 18 patients (24 screws) met inclusion criteria. The mean follow-up was 11.7 months (range = 6.0-14.7 months). 5/24 screws (21%) fractured at the break point. No screw fractured at another location, nor did any fracture prior to resumption of weight bearing; 19 screws did not fracture, with 8/19 intact screws (42.1%) demonstrating loosening. There was no evidence of syndesmotic diastasis or mortise malalignment on final follow-up. No screws required removal during the study period. Conclusion. This study provides the first clinical data on a novel screw introduced specifically for syndesmotic fixation. At short-term follow up, there were no complications and the R3lease screw provided adequate fixation to allow healing and prevent diastasis. Although initial results are favorable, longer-term follow-up with data on cost comparisons and rates of hardware removal are needed to determine cost-effectiveness relative to similar implants.Level of Evidence: Level IV: Retrospective case series.

Statistical Significance in Trauma Research: Too Unstable to Trust?

OBJECTIVES: To evaluate the stability of statistical findings in the fracture care literature based on minor changes in event rates and to determine the utility of applying both the Fragility Index (FI) and Fragility Quotient (FQ) to comparative orthopaedic trauma trials. METHODS: All fracture care studies from 1991 to 2013 in the Journal of Bone and Joint Surgery and the Journal of Orthopaedic Trauma were screened. The FI was determined by altering the number of reported outcome events, a single event at time, until a reversal of statistical significance was determined. The associated FQ was determined by dividing the FI by the total sample size. RESULTS: Of the 4040 studies evaluated, 198 comparative studies met inclusion criteria with a reported 253 primary and 522 secondary outcome events. There were 118 randomized controlled trials and 80 retrospective comparative studies. Of the 775 total outcome events, 235 were initially reported as significant. The median FI for the entire study was only 5 with an associated FQ of 0.046. This represents just 3.8% of the total study population. CONCLUSIONS: The robustness of comparative trials in the orthopaedic trauma literature may not be as stable as previously thought with only a few event reversals required to alter trial significance. We therefore recommend triple reporting of a P value, FI, and FQ to aid in the evaluation and interpretation of statistical stability and quantitative significance in comparative orthopaedic trauma trials.

Predicting survival in older patients treated for cervical spine fractures: development of a clinical survival score.

BACKGROUND CONTEXT: Emerging literature has identified the importance of pretreatment health and functional status as influential in the prognostication of survival. A comprehensive, accessible, predictive model for survival following cervical spine fracture has yet to be developed. PURPOSE: To develop an accessible and intuitive predictive model for survival in individuals aged 50 and older treated for cervical spine fractures. STUDY DESIGN: Retrospective review of records from two tertiary care centers (2009-2016). PATIENT SAMPLE: Patients age 50 and older who received operative or nonoperative management for cervical fractures. OUTCOME MEASURES: One-year mortality was the primary outcome with 3-month and 2-year mortality considered secondarily. METHODS: Multivariable logistic regression was used to identify factors independently associated with mortality. The magnitude and precision of the relationship with 1-year mortality for statistically significant variables determined weighting in the scoring system subsequently developed. Score performance was tested through multivariable regression and bootstrap simulation. In a sensitivity test, the performance of the score developed for 1-year mortality was assessed using figures for the 3-month and 2-year time-points. RESULTS: We included 1,758 patients. Mortality rates were 12% at 3 months, 17% at 1 year, and 21% at 2 years. Following multivariable testing age, injury severity score and Glasgow coma scale demonstrated the strongest predictive values for a base score, followed by serum albumin and ambulatory status. The resultant composite score ranged from 0 (base score≤4, albumin≤3.5 g/dL, and dependent/nonambulator at presentation) to a maximum of 4 (base score≥5, albumin>3.5 g/dL, and independent ambulator at presentation). Following multivariable analysis, when compared to patients with a score of 4, significantly increased odds of 1-year mortality were appreciated for those with scores of 3 (odds ratio [OR] 7.35; 95% confidence interval [CI] 3.77, 14.32), 2 (OR 8.43; 95% CI 4.66, 15.25), 1 (OR 17.47; 95% CI 9.81, 31.11), and 0 (OR 26.58; 95% CI 13.87, 50.92). Score performance was unchanged in bootstrap testing and sensitivity analyses. CONCLUSIONS: We have developed a useful prognostic utility capable of informing survival in individuals age 50 and older, following cervical spine fractures. The score can be applied to adjust patient expectations, anticipate outcomes, and as an adjunct to decision-making in the postinjury period.

Garden 1 and 2 Femoral Neck Fractures Collapse More Than Expected After Closed Reduction and Percutaneous Pinning.

OBJECTIVES: To report on the final displacement after in situ percutaneous pinning for Garden type 1 and 2 fractures in height, femoral neck fracture collapse, and loss of offset. DESIGN: Retrospectively reviewed case series. SETTING: Three Academic Medical Centers. Boston University Medical Center (Level 1 Trauma Center), Lahey Hospital and Medical Center (Level 2 Trauma Center), and Geisinger Medical Center (level 2 Trauma Center). PATIENTS/PARTICIPANTS: One hundred thirty skeletally mature patients with 130 fractures (78 garden 1 and 52 garden 2) who were treated between January 2000 and January 2014 at participating hospitals with percutaneous pinning with a cannulated screw system to successful union after sustaining an intracapsular femoral neck fracture without complete displacement. INTERVENTION: In situ percutaneous pinning with 3 cannulated, partially threaded screws in an inverted triangle orientation. MAIN OUTCOME MEASUREMENTS: Femoral neck fracture collapse (mm), femoral height shortening (mm), and femoral offset shortening (mm). RESULTS: A total of 130 patients (81F, 49M), average age 72 years, sustained 78 Garden 1 and 52 Garden 2 femoral neck fractures. Maximal collapse occurred in the plane of the femoral neck. Thirty-three of 78 (42%) Garden 1 fractures and 33/52 (63%) Garden 2 fractures demonstrated >10 mm fracture collapse. The range of displacements was 0-39 mm as measured along the plane of the femoral neck. CONCLUSIONS: Garden 1 fractures collapse less frequently than Garden 2 fractures, but both have high rates of fracture collapse when treated to union with in situ percutaneous pin fixation. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Statistical Fragility and the Role of P Values in the Sports Medicine Literature.

INTRODUCTION: Comparative trials evaluating categorical outcomes have important implications on surgical decision making. The purpose of this study was to examine the statistical stability of sports medicine research. METHODS: Comparative clinical sports medicine research studies involving anterior cruciate ligament, meniscus, and knee instability were reviewed in two journals between 2006 and 2016. The statistical stability for each study outcome was determined by the number of event reversals required to change the P value to either greater or less than 0.05. The number of patients lost to follow-up was also determined. RESULTS: Of the 1,505 studies screened, 102 studies were included for analysis, 40 of which were randomized controlled trials. There were 339 total outcome events, with 98 significant and 241 not significant. The Fragility Index, or the median number of events required to change the statistical significance of the overall study, was five (interquartile range, 3 to 8) or 5.4% of the total study population. In addition, the average number of patients lost to follow-up was 7.9, which is greater than the number needed to change the significance of each study arm and the entire study population. CONCLUSION: Results in the comparative sports medicine literature may not be as stable as previously thought, with only a small percentage of outcome events needed to change study significance. Outcomes research based on a single discreet P value cutoff may be misleading.

A Compatibility Guide for the Orthopaedic Surgeon Planning to Perform Hardware Removal Surgery.

BACKGROUND: Removal of previously placed orthopaedic implants is a commonly performed procedure worldwide. Given the diversity of orthopaedic implant manufacturers, surgeons may be uncertain whether they have the appropriate screwdriver on site. The purpose of this study was to assess the compatibility of screw head and size configurations from various orthopaedic manufacturers with two commonly used universal screw removal sets. METHODS: Inclusion of orthopaedic implant manufacturers was determined by market share based on industry-monitoring financial firms. Screw size and drive type for the top grossing orthopaedic implant manufacturers were collected and recorded. Screw and screwdriver compatibility was assessed and compared with two commonly used universal screw removal sets. RESULTS: In total, six orthopaedic implant companies with commonly implanted screws throughout the appendicular skeleton were included. The data were compiled in table format with noncannulated, cannulated, and locking screw offerings separated by the screw size and manufacturer. Guidewire size compatibility for cannulated offerings was also assessed. CONCLUSIONS: Given the ubiquity of implanted orthopaedic implant, removal must be as safe, planned, and controlled as possible. The data in this article provide an inclusive, centralized resource for surgeons looking to confirm the compatibility of previously implanted screws and available removal equipment at their institution.

Outcomes after plating of olecranon fractures: A multicenter evaluation.

INTRODUCTION: The aim of this study was to report the physical and functional outcomes after open reduction internal fixation of the olecranon in a large series of patients with region specific plating across multiple centres. PATIENTS/METHODS: Between January 2007 and January 2014, 182 consecutive patients with a displaced olecranon fracture treated with open reduction internal fixation were included in this study. Retrospective review across four trauma centres collected elbow range of motion, DASH scores, hardware complications, and hardware removal. Postoperative visits in the outpatient clinic were at two, six, and twenty-four weeks. After 24 weeks, patients were eligible for hardware removal if symptomatic. All patients were contacted, at least 1 year following surgery, to determine if hardware was removed. RESULTS: 182 patients (75 women, 105 men) average age 50 (16-89) with 162 closed and 19 open displaced olecranon fractures were treated with one region specific plate. Nineteen were lost to followup leaving 163 for analysis with all patients united. The most common deficiency was a lack of full extension with 39% lacking at least 10° of extension. Hardware was asymptomatic in 67%, painful upon leaning in 20%, and restricted activities in 11% resulting in a 15% rate of hardware removal. Hardware complaints were more common if a screw was placed in the corner of the plate (P=0.004). When symptomatic, the area of the plate that was bothersome encompassed the whole plate in 39%, was at the edge of the plate in 33%, and was a screw head in 28%. The DASH scores, collected at final follow-up of 24 weeks, was 10.1±16, indicating moderate disability was still present. Patients who lacked 10° of extension had a DASH of 12.3 as compared with 10.5 for those with near full extension, but this was not significant (P=0.5). CONCLUSION: Plating of the olecranon leads to predictable union. The most common complication was lack of full extension with 39% lacking more than 10°, although this did not have any effect on DASH scores. Overall results indicate that disability still exists after 6 months with an average DASH score of 10. LEVEL OF EVIDENCE: Therapeutic level III.