Heterotopic ossification (HO) is a well-known complication of traumatic elbow injuries. The reported rates of post-traumatic HO formation vary from less than 5% with simple elbow dislocations, to greater than 50% in complex fracture-dislocations. Previous studies have identified fracture-dislocations, delayed surgical intervention, and terrible triad injuries as risk factors for HO formation. There is, however, a paucity of literature regarding the accuracy of diagnosing post-traumatic elbow HO. Therefore, the purpose of our study was to determine the inter-rater reliability of HO diagnosis using standard radiographs of the elbow at 52 weeks post-injury, as well as to report on the rate of mature compared with immature HO. We hypothesized inter-rater reliability would be poor among raters for HO formation. Prospectively collected data from a large clinical trial was reviewed by three independent reviewers (one senior orthopedic resident, one senior radiology resident, and one expert upper extremity orthopedic surgeon). Each reviewer examined anonymized 52-week post-injury radiographs of the elbow and recorded: 1. the presence or absence of HO, 2. the location of HO, 3. the size of the HO (in cm, if present), and 4. the maturity of the HO formation. Maturity was defined by consensus prior to image review and defined as an area of well-defined cortical and medullary bone outside the cortical borders of the humerus, ulna, or radius. Immature lesions were defined as an area of punctate calcification with an ill-defined cloud-like density outside the cortical borders of the humerus, ulna or radius. Data were collected using a standardized online data collection form (CognizantMD, Toronto, ON, CA). Inter-rater reliability was calculated using Fleiss’ Kappa statistic and a multivariate logistic regression analysis was performed to identify risk factors for HO formation in general, as well as mature HO at 52 weeks post injury. Statistical analysis was performed using RStudio (version1.4, RStudio, Boston, MA, USA). A total of 79 radiographs at the 52-week follow-up were reviewed (54% male, mean age 50, age SD 14, 52% operatively treated). Inter-rater reliability using Fleiss’ Kappa was k= 0.571 (p = 0.0004) indicating moderate inter-rater reliability among the three reviewers. The rate of immature HO at 52 weeks was 56%. The multivariate logistic regression analysis identified male sex as a significant risk factor for HO development (OR 5.29, 1.55-20.59 CI, p = 0.011), but not for HO maturity at 52 weeks. Age, time to surgery, and operative intervention were not found to be significant predictors for either HO formation or maturity of the lesion in this cohort. Our study demonstrates moderate inter-rater reliability in determining the presence of HO at 52 weeks post-elbow injury. There was a high rate (56%) of immature HO at 52-week follow-up. We also report the finding of male sex as a significant risk factor for post traumatic HO development. Future research directions could include investigation into possible male predominance for traumatic HO formation, as well as improving inter-rater reliability through developing a standardized and validated classification system for reporting the radiographic features of HO formation around the elbow

The use of cannabis is increasingly medically relevant as it is legalized and gains acceptance more broadly. However, the effects of marijuana use on postoperative outcomes following orthopedic surgery have not been well-characterized. This study seeks to illuminate the relationship between marijuana use and the incidence postoperative complications including: DVT, PE, nonunion, and infection following common orthopedic procedures. This study was conducted using a national orthopaedic claims insurance database. We identified all patients undergoing knee arthroscopy, shoulder arthroscopy, operatively managed long bone fractures (humerus, femur, tibia and/or fibula, and radius and/or ulna), and single-level lumbar fusion. The proportion of patients within each surgery cohort who had a diagnostic code for marijuana dependence was assessed. The rates of DVT, PE, and infection within 90 days were assessed for all patients. The rate of nonunion was assessed for the long bone fracture and lumbar fusion cohorts. Univariate analyses of marijuana dependence on all outcomes were performed, followed by a multivariate logistic regression analysis controlling for known patient comorbidities. We identified 1,113,944 knee arthroscopy, 747,938 shoulder arthroscopy, 88,891 lumbar fusion, and 37,163 long bone fracture patients. Out of the 1,987,936 patients, 24,404 patients had a diagnostic code for marijuana dependence. Within all four surgical subgroups, the marijuana dependence cohort experienced increased rates of infection, PE, and DVT, as well as increased rates of nonunion in the lumbar fusion and long bone fracture populations. In the multivariate analyses controlling for a variety of patient risk factors including tobacco use, marijuana dependence was identified as an independent risk factor for infection within all four surgical subgroups (Knee: OR 1.85, p < 0.001; Shoulder: OR 1.65, p < 0.001; Spine: OR 1.45, p < 0.001; Long bone: OR 1.28, p < 0.001), and for nonunion in the lumbar fusion (OR 1.38, p < 0.001) and long bone fracture (OR 1.31, p < 0.001) subgroups. Our data suggests that marijuana dependence may be associated with increased rates of infection and nonunion following a variety of orthopaedic procedures. During preoperative evaluation, surgeons may consider marijuana use as a potential risk factor for postoperative complications, especially within the context of marijuana legalization. Future research into this relationship is necessary

Aim. Whether laminar airflow (LAF) in the operating room (OR) is effective for decreasing periprosthetic joint infection (PJI) following total joint arthroplasty (TJA) remains a clinically significant yet controversial issue. This study investigated the association between operating room ventilation systems and the risk of PJI in TJA patients. Method. We performed a retrospective observational study on consecutive patients undergoing primary total knee arthroplasty (TKA) and total hip arthroplasty (THA) from January 2013-September 2017 in two surgical facilities within a single institution, with a minimum 1-year follow-up. All procedures were performed by five board-certified arthroplasty surgeons. The operating rooms at the facilities were equipped with LAF and turbulent ventilation systems, respectively. Patient characteristics were extracted from clinical records. PJI was defined according to Musculoskeletal Infection Society criteria within 1-year of the index arthroplasty. A multivariate logistic regression model was performed to explore the association between LAF and risk of 1-year PJI, and then a sensitivity analysis using propensity score matching (PSM) was performed to further validate the findings. Results. A total of 6,972 patients (2,797 TKA, 4,175 THA) were included. The incidence of PJI within 1 year for patients from the facility without laminar flow was similar at 0·4% to that of patients from the facility with laminar flow at 0·5%. In the multivariate logistic regression analysis, after all confounding factors were taken into account, the use of LAF was not significantly associated with reduction of the risk of PJI. After propensity score matching, there was no significant difference in the incidence of PJI within 1 year for patients between the two sites. Conclusions. The use of LAF in the operating room was not associated with a reduced incidence of PJI following primary TJA. With an appropriate perioperative protocol for infection prevention, LAF does not seem to play a protective role in PJI prevention

Solitary fibrous tumor (SFT) is a rare mesenchymal tumor with an intermediate tendency to metastasize, which is found in many different locations including head and neck, abdomen, chest cavity and extremities. Also, meningeal hemangiopericytoma (HPC) is considered an SFT which arises in the meningeal membranes. SFT family shows an undetermined biologic behavior varying from a silent indolent tumor to an aggressive malignant form; however, benign and malignant variants of SFT may have similar cytopathologic characteristics. In this study, we defined the factors correlated with SFT's aggressive behavior and patient's survival. This is a retrospective study based on medical records of 85 patients who were suffering from SFT and had been treated at McGill University Health Centre (MUHC) between 1984 and 2017. We used multivariate logistic regression analysis to address any association between the variables including patient's demographics, tumor size, primary location of the tumor, pathological features, treatment methods and outcomes. The median of the follow-up period was 60 months. The patient's age or gender had no association with tumor aggressive behavior or patient's survival. Anatomical origin of primary tumor had no strong correlation with the patient's disease related death (DRD); however, tumors originated from CNS showed more aggressive behavior. There was an association between tumor size more than 7 cm and distant metastasis (MT) (p= 0.03) and DRD (p=0.03). The tumor size also correlated with the 5-year disease-free survival (p=0.017). We had three histologic groups: 1- Benign SFT (30 cases), 2- cellular SFT or HPC (29 cases), 3- malignant SFT or anaplastic HPC (26 cases). Although univariate analysis demonstrates that patients suffering from cellular SFT and malignant SFT showed increased aggressive behavior of the tumor, multivariate analysis didn't verify the mentioned association. Patients with positive margins had increased odds ratio to experience tumor local recurrence (LR) (p= 0.05) and LR was correlated with DRD in our patients (p=0.006). Radiotherapy had no statistical association with LR, MT or DRD. Frequency of LR and MT in the study were 25.7% and 29.8% respectively. 5-year disease-free survival in our patients was 76%. The size of SFT is the most correlative predictor of the tumor's aggressive behavior. The local recurrence of SFT is associated with disease related death; therefore, resection of the tumor with negative margins provides the highest chance of cure. In addition, a cellular SFT should be treated like a malignant variant of the tumor

Purpose. The hip fracture has been increasing as the aging population continues to grow. Hip fracture patients are more susceptible to blood loss and venous thromboembolism (VTE). The objective of this study was to assess the efficacy and safety of tranexamic acid (TXA) in fracture patients undergoing fast-track hemiarthroplasty. Methods. 609 hip fracture patients undergoing hemiarthropalsty from January 2013 to September 2016 were prospectively selected. 289 patients received 15 mg/kg TXA prior to surgery, and the remaining 320 patients received no TXA. All the patients received a fast-track program including nutrition management, blood management, pain management, VTE prophylaxis and early mobilization and early intake. The primary outcome was transfusion requirement, other parameters such as blood loss, hemoglobin (Hb) level, VTE, adverse events and length of hospital stay were also compared. Multivariate logistic regression analysis and meta-analysis were also performed to identify the risk factors of transfusion and confirm the results of current study. Results. Transfusion of at least 1U of erythrocyte blood cell occurred in 25 patients (8.65%) in treatment group and in 77 (24.06%, OR=0.299, p<0.001) in control group. The mean level of Hb on POD 1 (111.70±18.40 g/L) and POD 3 (108.16±17.25 g/L) in TXA group were higher than control group (107.29±18.70 g/L, p= 0.008; 104.22±15.16 g/L, p= 0.005 respectively). More patients get off bed to ambulate within 24 hours after surgery in TXA group (37.02% Vs 26.25%, p= 0.004). And the length of hospital stay was shorter (11.82±4.39 Vs 15.96±7.30, p= 0.003). No statistical significance were detected regarding VTE and other adverse events. Logistic regression analysis showed that the relative odds reduction after adjustment for these covariates was 67% (OR= 0.327, 95%CIs= 0.197 to 0.544) in favor of tranexamic acid. Other risk factors included preoperative hemoglobin level, operation time, VTE prophylaxis. Pooling the data showed that tranexamic acid led to a significant reduction in transfusion (OR= 0.33, 95%CIs= 0.25 to 0.43) without sacrificing safety (OR= 0.70, 95%CIs= 0.25 to 1.97). Conclusion. Tranexamic acid was effective and safe to reduce blood loss and transfusion in geriatric hip fracture patients undergoing fast-track hemiarthroplasty

Objective. By retrospective analysis of clinical data, to find new risk factors for postoperative dislocation after total hip replacement and the dose-effect relationship when multiple factors work simultaneously. Methods. A nested case-control study was used to collect the dislocated hips from 5513 primary hip replacement case from 2000 to 2012. Apart from the patients with given cause of dislocation, 39 dislocated hips from 38 cases were compared with 78 hip from 78 cases free from dislocation postoperatively, which matched by the admission time. The factors that may affect the prosthetic unstable was found by the univariate analysis, and then they were performed multivariate logistic regression analysis and evaluation of a dose-effect factors. Results. The clinical scores between the two groups was no significant difference before and after surgery. Univariate analysis revealed the position of acetabular prosthesis (P = 0.05) and the big ball (P=0.01) differences were statistically significant. While patient with adduction deformity incorporating limb lengthening≧2cm(P<0.01) or the knee valgus deformity incorporating pelvic obliquity (P=0.01), as well as bilateral cases (P=0.02) were also the risk factors for dislocation. Big head decrease the dislocation rate. Multivariate analysis confirmed these newly founded factors are more important than the classic factors in this group of patients. Conclusion. Patients with hip adduction deformity combined with limb lengthening, knee valgus deformity combined with pelvic obliquity and bilateral pathological hip seem more predisposed to dislocation after total hip arthroplasty, who should be strengthened preoperative education and postoperative management to prevent. Key Word. total hip arthroplasty, dislocation, multivariate analysis

Purpose. Pediatric tibial shaft fractures (TSF) account for 15% of long bone fractures in children. Compartment syndrome (CS) is difficult to diagnose in children, often leading to disastrous outcomes. This study investigated the incidence of CS in TSF and its associated risk factors. Method. A detailed five-year retrospective chart review of TSF treated at a major pediatric hospital. CS was diagnosed clinically or by intra-compartment pressure. Multivariate logistic regression analysis tested age, gender, mechanism of injury, time to surgery, fracture type, and treatment intervention as possible risk factors for CS. Results. There were 216 TSF in 212 children (160 males, 52 females; mean age 13.6 years, range eight-18 years). One hundred and thirty-two (61%) fractures were treated with closed reduction and casting, 36 with external fixation, 21 with flexible intramedullary nails, and 27 with locked intramedullary nails. There were 23 cases of CS (10.6%). Multivariate predictors of CS included age 14 years and older (21/96 = 22%, p < 0.001) and motor vehicle accident (MVA) (12/57 = 21%, p = 0.002). Incidence of CS was 44% among patients 14 and older who sustained MVA (11 of 25). Gender, AO fracture type, time to surgery and surgical fixation were not predictive of CS. Conclusion. This is the first large study to report the incidence of CS from TSF in children. The incidence of 10.6% is higher than previously reported and much higher in patients 14 years of age and older and involved in an MVA. Surgeons should be especially aware and suspicious of CS in children with tibial shaft fractures who have these risk factors

Hypothesis. Does the result of steroid injection in the carpal tunnel in a patient with recurrent carpal tunnel symptoms provide a good predictor of the outcome of later carpal tunnel release (CTR). Methods. A retrospective review of all patients who underwent revision CTR for recurrent or persistent carpal tunnel syndrome (CTS) over a two year period was conducted. A total of 23 patients and 28 wrists met inclusion criteria. Patients were evaluated to determine if pre-operative factors or result of injection predicted the outcome of revision CTR. A multivariate logistic regression analysis (MLRA) was used to predict surgical success when multiple pre-operative findings were considered. Results. No patient characteristic or physical exam finding was found to predict successful revision CTR. Twenty-two (86.4%) of patients who had relief from injection had symptom relief/improvement with revision CTR whereas only 4 (13.6%) were not improved by the surgery; the difference was not statistically significant. The sensitivity and positive predictive value for injection alone predicting outcome of revision CTR was 86.4%. MLRA combining injection results with physical exam findings (Numbness and/or motor weakness in median nerve distribution, Positive Durkin's, and Positive Phalen's test) provided a sensitivity of 100% and specificity of 80%. Conclusions. In contrast to primary CTS, cortisone injection into the carpal tunnel in the face of recurrent CTS is not, by itself, a statistically significant predictor of successful revision surgery. However, patients with a positive result from injection had an 86.4% success with revision CTR with an average DASH score of 28.87. Relief from injection as a diagnostic test for success from revision CTR was found to have both high sensitivity and positive predictive value. Coupled with the components of the physical examination, injection provides a good screening test to establish success with revision CTR, sensitivity of 100% and specificity of 80%

Background. The anterior approach for total hip arthroplasty has recently been hypothesized to result in less muscle damage. While clinical outcome studies are essential, they are subject to patient and surgeon bias. We prospectively analyzed biochemical markers of muscle damage and inflammation in patients receiving anterior and posterior minimally-invasive total hip arthroplasty to provide objective evidence of the surgical insult. Methods. 29 patients receiving an anterior and 28 patients receiving a posterior total hip arthroplasty were analyzed. Peri-operative and radiographic data were collected to ensure similar cohorts. Creatine kinase, C-reactive protein, Interleukin-6, Interleukin-1beta, and Tumor necrosis factor-alpha were collected pre-operatively, post-operatively, and on post-operative days 1 and 2. Comparisons between the groups were made using the Student's t-test and Fisher's Exact test. Independent predictors of elevation in markers of inflammation and muscle damage were determined using multivariate logistic regression analysis. Results. Markers of inflammation were slightly decreased in direct anterior group (mean differences in C-reactive protein 27.5 [95% confidence interval −24.7–79.6] mg/dL, Interleukin-6 13.5 [95% confidence interval −11.5–38.4] pg/ml, Interleukin-1beta 42.6 [95% confidence interval −10.4–95.6], and Tumor necrosis factor-alpha 148.6 [95% confidence interval −69.3–366.6] pg/ml). The rise in creatine kinase was 5.5 times higher in the post anesthesia care unit (mean difference 150.3 [95% confidence interval 70.4–230.2] units/L, p < 0.05) and nearly twice as high cumulatively in the miniposterior approach group (305.0 [95% confidence interval −46.7–656.8] units/L, p < 0.05). Conclusion. Anterior total hip arthroplasty caused significantly less muscle damage compared to traditional posterior surgery as indicated by creatine kinase levels. The clinical importance of this rise needs to be delineated by further clinical studies. The overall physiologic burden as measured by markers of inflammation, however, appears to be similar. Objective measurement of muscle damage and inflammation provides an unbiased way of determining the immediate effects of surgical intervention in total hip arthroplasty patients

Background The minimum size required for a successful quadrupled hamstring autograft ACL reconstruction remains controversial. The risks of ACL re-tear in younger patients who tend to participate in a higher level of sports activity, and female athletes who have numerous predisposing factors, are poorly defined. Purpose To identify risk factors for graft re-tears within 2 years of ACL surgery. The hypotheses are that female sex, a smaller size graft, and younger patients will increase the odds of failure. Study Design Cohort Study. Level of evidence, 3. A cohort of 503 athletes undergoing primary, autograft hamstring ACL reconstruction, performed by a single surgeon using the same surgical technique and rehabilitation protocol, between September-December 2012, was followed for a total duration of 2 years. Return to play was allowed between 6 and 12 months post-surgery upon completion of functional testing. Exclusion criteria included infections, revisions, double bundle techniques, multi-ligament injuries, non-compliance, BTB/allografts/hybrid grafts. Primary outcome consisted of binary data (ACL graft re-tear or no tear) as measured on physical exam (Lachman and pivot shift) and MRI. Multivariate logistic regression statistical analysis with model fitting was used to investigate the predictive value of sex, age, and graft size on ACL re-tear. Secondary sensitivity analyses were performed on the adolescent subgroup, age and graft size as categorical variables, and testing for interactions among variables. Sample size was calculated based on the rule of 10 events per independent variable for logistic regression. The mean age of the 503 athletes was 27.5 (SD 10.6; range = 12–61). There were 235 females (47%) and 268 males (53%) with a 6 % rate of re-tears (28 patients; 17 females). Mean graft size was 7.9 (SD 0.6; range = 6–10). Univariate analyses of graft size, sex, and age only in the model showed that younger age (odds ratio [OR] = 0.86; 95% confidence interval [CI] = 0.80–0.93; P = .001] and smaller graft size (OR = 0.36; 95% CI = 0.18–0.70; P = .003) were significantly predictive of re-tear. Female sex was correlated with re-tear but was not significant (OR = 1.8; 95% CI = 0.84–3.97; P = .13). Multivariate analysis with all 3 variables in the model showed similar significant results. Graft size < 8 mm (OR = 2.95; 95% CI = 1.33–6.53; P = .008) and age < 25 (OR = 7.01; 95% CI = 2.40–20.53; P = .001) were significantly predictive of re-tear. Entire model was statistically significant (Omnibus test P = .001; Hosmer-Lemeshow statistic P = .68; Receiver Operating Curve [ROC] = 0.8). Surgeons should counsel their patients who are female, younger than 25 and with a graft size less than 8 mm accordingly and consider modifying their surgical or rehabilitation techniques to mitigate these re-tear risks

Aims

The timing of when to remove a circular frame is crucial; early removal results in refracture or deformity, while late removal increases the patient morbidity and delay in return to work. This study was designed to assess the effectiveness of a staged reloading protocol. We report the incidence of mechanical failure following both single-stage and two stage reloading protocols and analyze the associated risk factors.

Introduction

Studies have addressed the issue of increasing prevalence of work-related musculoskeletal (MSK) pain among different occupations. However, contributing factors to MSK pain have not been fully investigated among orthopaedic surgeons. Thus, this study aimed to approximate the prevalence and predictors of MSK pain among Saudi orthopaedic surgeons working in Riyadh, Saudi Arabia.