Abstract. Background. Extracorporeal radiation therapy (ECRT) has been reported as an oncologically safe and effective reconstruction technique for limb salvage in diaphyseal sarcomas with promising functional results. Factors affecting the ECRT graft-host bone incorporation have not been fully investigated. Methods. In our series of 51 patients of primary bone tumors treated with ECRT, we improvised this technique by using a modified V-shaped osteotomy, additional plates and intra-medullary fibula across the diaphyseal osteotomy in an attempt to increase the stability of fixation, augment graft strength and enhance union at the osteotomy sites. We analyzed our patients for various factors that affected union time and union rate at the osteotomy sites. Results. On univariate analysis, age <20 years, metaphyseal osteotomy site, V-shaped diaphyseal osteotomy, extramedullary plate fixation and use of additional plate at diaphyseal ostetomy had a significantly faster time to union while gender, tumor type, resection length, chemotherapy and use of intra-medullary fibula did not influence union time. In multivariate analysis, metaphyseal ostoeotomy, V-shaped diaphyseal osteotomy and use of additional plate at diaphyseal ostetomy were the independent factors with favourable time to union. Although the rate of union was higher with V-shaped diaphyseal osteotomy and use of additional plate and intra-medullary fibula at diaphyseal ostetomy, this difference could not be established statistically. None of the analyzed factors apparently affected the union rate in univariate analysis. Conclusion. Judicious choice of osteosynthesis and augmentation of ECRT graft can enhance incorporation with reduced complications and good functional outcome

Traditional staging systems for high grade osteosarcoma (Enneking, MSTS) are based largely on gross surgical margins and were developed before the widespread use of neoadjuvant chemotherapy. It is now well known that both microscopic margins and chemotherapy are predictors of local recurrence. However, neither of these variables are used in the traditional surgical staging and the precise safe margin distance is debated. Recently, a novel staging system utilizing a 2mm margin cutoff and incorporating precent necrosis was proposed and demonstrated improved prognostic value for local recurrence free survival (LRFS) when compared to the MSTS staging system. This staging system has not been validated beyond the original patient cohort. We propose to analyze this staging system in a cohort of patients with high-grade osteosarcoma, as well as evaluate the ability of additional variables to predict the risk of local recurrence and overall survival. A retrospective review of a prospectively collected database of all sarcoma patients between 1985 and 2020 at a tertiary sarcoma care center was performed. All patients with high-grade osteosarcoma receiving neo-adjuvant chemotherapy and with no evidence of metastatic disease on presentation were isolated and analyzed. A minimum of two year follow up was used for surviving patients. A total of 225 patients were identified meeting these criteria. Univariate analysis was performed to evaluate variable that were associated with LRFS. Multivariate analysis is used to further analyze factors associated with LRFS on univariate analysis. There were 20 patients (8.9%) who had locally recurrent disease. Five-year LRFS was significantly different for patients with surgical margins 2mm or less (77.6% v. 93.3%; p=0.006) and those with a central tumor location (67.9 v. 94.4; <0.001). A four-tiered staging system using 2mm surgical margins and a percent necrosis of 90% of greater was also a significant predictor of 5-year LRFS (p=0.019) in this cohort. Notably, percent necrosis in isolation was not a predictor of LRFS in this cohort (p=0.875). Tumor size, gender, and type of surgery (amputation v. limb salvage) were also analyzed and not associated with LRFS. The MSTS surgical margin staging system did not significantly stratify groups (0.066). A 2mm surgical margin cutoff was predictive of 5-year LRFS in this cohort of patients with localized high-grade osteosarcoma and a combination of a 2mm margin and percent necrosis outperformed the prognostic value of the traditional MSTS staging system. Utilization of this system may improve the ability of surgeons to stage thier patients. Additional variables may increase the value of this system and further validation is required

The optimum indications for debridement, antibiotics and implant retention (DAIR) are unclear. Previous studies have demonstrated higher success rate of DAIR within one year of the primary arthroplasty. This study aimed to compare the success rate of DAIR vs revision in “early” and “late” infections to provide guidance for clinical decision making. The Prosthetic Joint Infection in Australia and New Zealand Observational (PIANO) cohort prospectively recorded PJIs between July 2014 and December 2017 in 27 hospitals. This study included PIANO patients with first time PJIs occurring after primary TKA. Treatment success was defined as the patient being alive, free from further revision and without clinical or microbiological evidence of reinfection at two years follow-up. “Early” and “late” infections were analyzed separately. Univariate analysis compared demographic and disease specific factors between the DAIR and Revision groups. Multivariate binary logistic regression identified whether treatment strategy and other risk factors were associated with treatment success in “early” and “late” infections. In 117 “early” (<1 year) infections, treatment success rate was 56% in the DAIR group and 54% in the revision group (p=0.878). No independent risk factors were associated with treatment outcome on multivariate analysis. In 134 “late” (>1 year) infections, treatment success rate was 34.4% in the DAIR group and 60.5% in the revision group (OR 3.07 p=0.006). On multivariate analysis, revision was associated with 2.47x higher odds of success (p=0.041) when compared to DAIR, patients with at least one significant co-morbidity (OR 2.27, p=0.045) or with Staphylococcus aureus PJIs (OR 2.5, p=0.042) had higher odds of failure. In “late” PJIs occurring >1 year following primary TKA, treatment strategy with revision rather than DAIR was associated with greater success. Patients with significant comorbidities and Staphylococcus aureus PJIs were at higher risk of failure regardless of treatment strategy

Aims. Hip fracture is a common injury in the elderly. Recent studies in orthopaedic access have demonstrated inequities affecting Māori. This study aimed to compare the demographic differences between Māori and NZ Europeans with hip fractures, identify any deficiencies in initial, surgical and post op care and in outcomes. Methods. All cases in New Zealand from 2018–2020 were included. Key outcomes included time to theatre from admission, change in walking status, residential status and survival at 120 days post fracture. Univariate analysis compared differences in demographics, surgical and management factors between ethnicities. Key outcome comparisons were conducted using multivariate analysis to assess whether ethnicity was an independent risk factor for outcomes. Results. Data from 9432 patients were analysed. 305 patients were Māori (3.2%). Māori were younger at presentation (76.2 vs 83.2 yrs, p<0.001), used less walking aids (50 vs 56%, p=0.034), were more medically comorbid and more likely to have impaired cognition (42% vs 37%, p=0.022). There were no differences in fracture types, surgical management strategy, and nerve block utilisation between ethnicities. No perioperative management differences were found. Māori had a longer delay to theatre (39 vs 35hrs, p=0.007), and were less likely to be prescribed bone protection on discharge (64% vs 71%, p=0.011). Once adjusted location and ASA, difference in time to theatre was not statistically significantly. Overall mortality was 13.1% at 120 days. 45% had a reduction in walking ability while 15% required increase level of care. Multivariate analysis found no differences were found between ethnicities for mortality, change in residential or walking status. Discussion. While younger at presentation, Māori are more co-morbid and may live in DHBs with worse theatre access, contributing to a longer time to theatre. Improving access to tertiary care and overall health of older Māori will likely improve outcomes

The Lisfranc fracture dislocation of the tarsometatarsal joint (TMTJ) is a complex injury with a reported incidence of 9.2 to 14/100,000 person-years. Lisfranc fixation involves dorsal bridge plating, transarticular screws, combination or primary arthrodesis. We aimed to identify predictors of poor patient reported outcome measures at long term follow up after operative intervention. 127 patients underwent Lisfranc fixation at our Level One Trauma Centre between November 2007 and July 2013. At mean follow-up of 10.7 years (8.0-13.9), 85 patients (66.92%) were successfully contacted. Epidemiological data including age, gender and mechanism of injury and fracture characteristics such as number of columns injured, direction of subluxation/dislocation and classification based on those proposed by Hardcastle and Lau were recorded. Descriptive analysis was performed to compare our primary outcomes (AOFAS and FFI scores). Univariate analysis and multivariate regression analysis was done adjusted for age and sex to compare the entirety of our data set. P<0.05 was considered significant. The primary outcomes were the American Orthopaedic Foot and Ankle Society (AOFAS) Midfoot Score and the Foot Function Index (FFI). The number of columns involved in the injury best predicts functional outcomes (FFI, P <0.05, AOFAS, P<0.05) with more columns involved resulting in poorer outcomes. Functional outcomes were not significantly associated with any of the fixation groups (FFI, P = 0.21, AOFAS, P = 0.14). Injury type by Myerson classification systems (FFI, P = 0.17, AOFAS, P = 0.58) or open versus closed status (FFI, P = 0.29, AOFAS, P = 0.20) was also not significantly associated with any fixation group. We concluded that 10 years post-surgery, patients generally had a good functional outcome with minimal complications. Prognosis of functional outcomes is based on number of columns involved and injured. Sagittal plane disruption, mechanism and fracture type does not seem to make a difference in outcomes

This study aimed to identify factors associated with increased rates of blood transfusion in patients with adolescent idiopathic scoliosis (AIS) treated with posterior spinal fusion (PSF). A retrospective case-control study was performed for AIS patients treated at a large children's hospital between August 2018 and December 2020. All patients with a diagnosis of AIS were evaluated. Data on patient demographics, AIS, and transfusion parameters were collected. Univariate regression and multivariate logistic modeling were utilized to assess risk factors associated with requiring transfusion. Odds ratios (OR) and 95% confidence interval (CI) were calculated. Surgeries were done by three surgeons and thirty anesthesiologists. To quantify the influence of anesthesia practice preferences a categorical variable was defined as “higher-transfusion practice preference”, for the provider with the highest rate of transfusion. A total of 157 AIS patients were included, of whom 56 were transfused RBC units (cases), and 101 did not receive any RBC transfusion (controls). On univariate analysis, the following variables were significantly correlated with receiving RBC transfusion: “higher-transfusion practice preference,” “administration of crystalloids,” “receiving fresh frozen plasma (FFP),” “receiving platelets,” “pre-operative hemoglobin,” “cell saver volume,” and “surgical time.” On multiple regression modeling, “pre-operative hemoglobin less than 120 g/L” (OR 14.05, 95% CI: 1.951 to 135.7) and “higher-transfusion practice preference” (OR 11.84, 95% CI: 2.505 to 63.65) were found to be meaningfully and significantly predictive of RBC transfusion. In this cohort, we identified pre-operative hemoglobin of 120 g/L as a critical threshold for requiring transfusion. In addition, we identified significant contribution from anesthesia transfusion practice preferences. Our multivariate model indicated that these two factors are the major significant contributors to allogenic blood transfusion. Although further studies are required to better understand factors contributing to transfusion in AIS patients, we suggest standardized, peri-operative evidence-based strategies to potentially help reduce variations due to individual provider preferences

Aim. One of the surgical therapeutic options for periprosthetic joint infection (PJI) includes debridement, antibiotics, and implant retention (DAIR). Prognostically favorable criteria for DAIR include short duration of symptoms, stable implant, pathogen susceptible to a ‘biofilm-active’ antimicrobial agent, and intact soft-tissue conditions. Despite this, there is a proportion of failures after DAIR, possibly because the duration of infection is underestimated. With the hypothesis that the duration of infection correlates with the bacterial load, and hence, the bacterial load is associated with failure after DAIR, we aimed to investigate the association of bacterial load in the sonication fluid of mobile parts and clinical outcome after DAIR. Method. From our PJI cohort (2010–2021), patients with DAIR (both palliative and curative approaches) were reviewed retrospectively. Patients with hip, knee or shoulder arthroplasties fulfilling infection definition, available sonication results, and ≥2 years follow-up were included. Sonication results were categorized in ≤ or >1000 cfu/mL. Univariate analysis was performed to identify predictors for DAIR failure. Results. Out of 209 PJIs, we identified 96 patients (100 PJIs, 47.8%) with DAIR. In 67 (69.8%) patients with 71 PJIs, there was a follow-up of ≥2 years. The mean age was 72.7 (SD 12.99) years, 50% were male. The infection affected 36 hips (50.7%), 32 knees (45.1%) and 3 shoulders (4.2%). At follow-up, there were 29 (40.8%) cured and 42 (59.2%) failed cases. When comparing failed and cured cases, we found no difference in comorbidities and previously defined risk factors for PJI, ASA score, Charlson score, anatomic location, no. of previous surgeries, pathogenesis of infection or laboratory values. The proportion of patients with high bacterial load on mobile parts (i.e. >1000 cfu/mL) was significantly higher in the failed DAIR group than it was in the cured group (61.9% vs 20.7%, p<0.001). Conclusions. In this study, a high bacterial load in sonication fluid of mobile parts was associated with failure after DAIR in patients with PJI. Sonication may help to differentiate acute hematogenous seeding to the implant and late reactivation of a previously silent implant-associated infection

Lisfranc injuries account for 0.2% of all fractures and have been linked to poorer functional outcomes, in particular resulting in post-traumatic arthritis, midfoot collapse and chronic pain. This study assesses the longitudinal functional outcomes in patients with low and high energy Lisfranc injuries treated both operatively and non-operatively. Patients above 16 years with Lisfranc injuries from January 2008 and December 2017 were identified through the Victorian Orthopaedic Trauma Outcomes (VOTOR) registry. Follow-up performed at 6, 12 and 24 months through telephone interviews with response rate of 86.1%, 84.2% and 76.2% respectively. Longitudinal functional outcome data using Global Outcome Assessment, EQ-5D-5L, numerical pain scale, Short-Form 12, the WHO Disability Assessment Schedule and return to work status were collected. Univariate analysis was performed and variables showing a significant difference between groups (p < 0.25) were analysed with multivariable mixed effects regression model. 745 patients included in this retrospective cohort study. At 24 months, both the operative and non-operative groups demonstrated similar functional outcomes trending towards an improvement. Mixed effect regression models for the EQ items for mobility (OR 1.80, CI 0.91 – 3.57), self-care (OR 1.95, 95% CI 1.09-3.49), usual activities (OR 1.10, 95% CI 0.99-1.03), pain (OR 1.07, 95% CI 0.61-1.89), anxiety (OR 1.29, 95% CI 0.72-2.34) and pain scale (OR 1.07, 95% CI 0.51 – 2.22) and return to work (OR 1.28, 95% CI 0.56-2.91) between groups were very similar and not statistically significantly different. We concluded that there was no statistically significant difference between operative and non-operative patients with low and high energy Lisfranc injuries. Current clinical practices in Lisfranc injury management are appropriate and not inadvertently causing any further harm to patients. Future research comparing fracture patterns, fixation types and corresponding functional outcomes can help determine gold standard Lisfranc injury management

Aims. Fracture-Related Infection (FRI) is a severe complication caused by microbial infection of bone. It is imperative to gain more insight into the potentials and limitations of Debridement, Antibiotics and Implant Retention (DAIR) to improve future FRI treatment. The aims of this study were to: 1) determine how time to surgery affects the success rate of DAIR procedures of the lower leg performed within 12 weeks after the initial fracture fixation operation and 2) evaluate whether appropriate systemic antimicrobial therapy affects the success rate of a DAIR procedure. Methods. This multinational retrospective cohort study included patients of at least 18-years of age who developed an FRI of the lower leg within 12 weeks after the initial fracture fixation operation, between January 1st 2015 to July 1st 2020. DAIR success was defined by the absence of recurrence of infection, preservation of the affected limb and retention of implants during the initial treatment. The antimicrobial regimen was considered appropriate if the pathogen(s) was susceptible to the given treatment at the correct dose as per guideline. Logistic regression modelling was used to assess factors that could contribute to the DAIR success rate. Results. A total of 120 patients were included, of whom 70 DAIR patients and 50 non-DAIR patients. Within a median follow-up of 35.5 months, 21.4% of DAIR patients developed a recurrent FRI compared to 12.0% of non-DAIR patients. The DAIR procedure was successful in 45 patients (64.3%). According to the Willenegger and Roth classification, DAIR success was achieved in 66.7% (n=16/24) of patients with an early infection (<2 weeks), 64.4% (n=29/45) of patients with a delayed infection (2–10 weeks) and 0.0% (0/1) of patients with a late infection (>10 weeks). Univariate analysis showed that the duration of infection was not associated with DAIR success in this cohort (p=0.136; OR: 0.977; 95%CI: [0.947–1.007]). However, an appropriate antimicrobial regimen was associated with success of DAIR (p=0.029; OR: 3.231; 95%CI: [1.138–9.506]). Conclusions. Although the results should be interpreted with caution, an increased duration of infection was not associated with a decreased success rate of a DAIR procedure in patients with FRI of the lower leg. The results of this study highlight the multifactorial contribution to the success of a DAIR procedure and emphasize the importance of adequate antimicrobial treatment. Therefore, time to surgery should not be the only key-factor when considering a DAIR procedure to treat FRI

Aims. Using the Australian and New Zealand Hip Fracture Registry (ANZHFR) data, this study aimed to identify patient, fracture, and management factors associated with survival, mobility and residential status at 120 days. This will allow future interventions to target modifiable risk factors to improve the overall care of patients with hip fractures. Methods. All NZ patients from 2018 – 2020 were included. Baseline demographics, management factors, and outcomes were recorded. Key outcomes were change in walking status, residential status and survival at 120 days. Univariate analysis was performed to compare differences in demographics, surgical and management factors for the key variables. Multivariate analysis was conducted to identify factors independently associated with outcomes. Results. Data from 9432 patients were analysed. The average age was 82.8 years (SD 9.8). 70.3% were females. 39.5% of patients were cognitively impaired on admission, 71.4% were from their own residence. At 120 days post injury, 10.9% (1029) had died 1029 (10.9%), 15.3% (1034) had a decrease in their residential status, 44.9% (2966) had a reduction in walking ability. On multivariate analysis; older age (RR1.1/yr, p<0.001), male sex (RR1.7, P<0.001), cognitive impairment (RR2.2, p<0.001) and ASA>3 (RR3.7, p=0.015) were risk factors for death. Similarly, increasing age (RR1.1 per year, p<0.001), cognitive impairment (RR1.2, p=0.04) and ASA>3 (RR2.9, p=0.047) were significant risk factors for worsening residential status. Decreasing mobility was associated with extracapsular fractures (RR1.4, p=0.01). After adjustment for demographics, ASA and fracture type, performing total hip arthroplasty was preventative for both worsening residential status (RR0.23, p<0.001) and decreasing walking ability (RR 0.21, p<0.001). There was no significant survival, functional or revision differences for other fixation types. Conclusion. There is a significant decline in walking ability post hip fracture which may be a key contributor to long-term morbidity. The benefits of THA in preserving mobility and independence should be further investigated. Additional discharge planning and multi-disciplinary team input are likely required for high-risk patients of older age, with cognitive impairment and extracapsular fractures

En bloc resection for primary bone tumours and isolated metastasis are complex surgeries associated with a high rate of adverse events (AEs). The primary objective of this study was to explore the relationship between frailty/sarcopenia and major perioperative AEs following en bloc resection for primary bone tumours or isolated metastases of the spine. Secondary objectives were to report the prevalence and distribution of frailty and sarcopenia, and determine the relationship between these factors and length of stay (LOS), unplanned reoperation, and 1-year postoperative mortality in this population. This is a retrospective study of prospectively collected data from a single quaternary care referral center consisting of patients undergoing an elective en bloc resection for a primary bone tumour or an isolated spinal metastasis between January 1st, 2009 and February 28th, 2020. Frailty was calculated with the modified frailty index (mFI) and spine tumour frailty index (STFI). Sarcopenia, determined by the total psoas area (TPA) vertebral body (VB) ratio (TPA/VB), was measured at L3 and L4. Regression analysis produced ORs, IRRs, and HRs that quantified the association between frailty/sarcopenia and major perioperative AEs, LOS, unplanned reoperation and 1-year postoperative mortality. One hundred twelve patients met the inclusion criteria. Using the mFI, five patients (5%) were frail (mFI ³ 0.21), while the STFI identified 21 patients (19%) as frail (STFI ³ 2). The mean CT ratios were 1.45 (SD 0.05) and 1.81 (SD 0.06) at L3 and L4 respectively. Unadjusted analysis demonstrated that sarcopenia and frailty were not significant predictors of major perioperative AEs, LOS or unplanned reoperation. Sarcopenia defined by the CT L3 TPA/VB and CT L4 TPA/VB ratios significantly predicted 1-year mortality (HR of 0.32 per one unit increase, 95% CI 0.11-0.93, p=0.04 vs. HR of 0.28 per one unit increase, 95% CI 0.11-0.69, p=0.01) following unadjusted analysis. Frailty defined by an STFI score ≥ 2 predicted 1-year postoperative mortality (OR of 2.10, 95% CI 1.02-4.30, p=0.04). The mFI was not predictive of any clinical outcome in patients undergoing en bloc resection for primary bone tumours or isolated metastases of the spine. Sarcopenia defined by the CT L3 TPA/VB and L4 TPA/VB and frailty assessed with the STFI predicted 1-year postoperative mortality on univariate analysis but not major perioperative AEs, LOS or reoperation. Further investigation with a larger cohort is needed to identify the optimal measure for assessing frailty and sarcopenia in this spine population

The prevalence of alcohol and opioids in severely injured patients has been widely reported from 30-80%. However, despite the increasing global misuse of stimulant drugs, there is a paucity of literature regarding the presence of stimulant drugs in trauma patients. The primary aim of this study was to define the prevalence of stimulant drugs that were detected in patients who presented to Level One Trauma Centers throughout North America, and their effect on length of stay and mortality. Our triage criteria for admittance to the regional trauma centre are based on the recommendations by the American College of Surgeons Committee on Trauma, who now recommend toxicology screening on every patient. This was a retrospective analysis of data from the Trauma Quality Improvement Program, including all patients presenting emergently to participating Level 1 Trauma Centers from January 2017 to December 2018. A stimulant drug was defined as the detection of cocaine, amphetamine, or methamphetamine. Adults aged 18-64 years were included. Patient risk factors were included adjusted for in the analysis: age, sex, body mass index (BMI), alcohol screening results and smoking status. Univariate analysis was performed for all variables. Multivariable logistic regression and liner regression were used for mortality and length of stay, respectively. Of a total of 110,561 patients included in the study, 15,958 patients (14.4%) had positive screens for stimulants. The average age in the stimulants cohort was 40.8 years, with a 77.6% male preponderance, BMI of 26.9, blood alcohol content of 0.07, and ISS of 11.3. The control cohort was comparable, though 71.1% male (p<0.001) Patients who tested positive for stimulants had 1.79 times (95% CI, 1.09-2.93) the odds of dying in the emergency department as the control group (p=0.02). Following transfer from the emergency department, the odds ratio for deaths in hospital (OR=1.02, 95% CI 0.90-1.15) was comparable to the control group (p=0.78). The mean length of stay was significantly higher in the stimulant group (2.84 days) compared to the control group (1.79 days) (p<.001). In the Intensive Care Unit, length of stay was 0.64 days in the stimulant group versus 1.65 in the control (p=0.48). Stimulant misuse is a relevant issue in the trauma population, associated with a longer hospital stay and higher mortality in the emergency department. The continued routine drug screening of trauma patients may be beneficial in trauma centers, to implement preventative measures and optimise resource allocation

Aim. To describe the management of PJI due to S. aureus in CRIOAcs in 2019 and to particularly focus on the evaluation of the efficacy of DAIR regarding control of infection and risk factors for failure up to 12 months. Method. Thirteen CRIOAcs were selected to participate to the study. Data concerning the management of all the PJI in the year 2019 were retrospectively collected and registered in eCRFs. Inclusion criteria were: ≥ 18 years old patients with S. aureus ± other bacteria (in per surgical procedure sample); knee or hip PJI and with clinical signs of infection. Patients treated with bacteriophages were excluded. All eligible patients were notified by an information letter. Patients treated by the DAIR procedure were selected, and rate of control of infection (no inflammatory local signs or no new surgical procedure or no S. aureus in case of puncture) was analyzed using Kaplan Meier method and risk factors for failure at 12 months were assessed using Cox regression model. Results. A total of 978 PJI were managed in the 9 CRIOAcs, including 238 hip and knee PJI due to S. aureus and 79 to S. aureus plus another bacteria. Among all of them, 154 were managed with DAIR, and 100 fulfilled inclusion criteria, notifying no opposition to their data collection. The median age was 73.0 years; 57% were male, the median Charlson score was 4.0; 66% had hip PJI. A total of 45 failure were observed during the period studied. At 12 months, the control rate was 58. 7% [36.5–75.4], 49.3% [34.3–62.7] in in early and late PJI respectively according to Tsukuyama classification and 49.6% [30.5–66.1], 54.1% [37.7 – 68.0] in early and delayed/late PJI respectively according to Zimmerli classification, 56.6% [39.5–70.5] in case of mobile part exchange, 53.4% [35.3–68.5] for MRSA PJI and 63.4% [50.5–73. 8] in patients treated with rifampicin. No rifampicin intake was the only significative risk factor for failure in univariate analysis (HR=0.31 (0.17–0.57), p=0.0002), and remained significant after adjustment on Charlson score (aHR=0.34 (0.18–0.64), p=0.0008). Conclusions. The DAIR procedure is frequently performed in patients with acute and late PJI, and is associated with a high rate of failure, especially for patients who cannot receive rifampin. There is a strong rational to assess the use of bacteriophages during the DAIR, as bacteriophages have antibiofilm activity in vitro, and could improve the efficacy of the DAIR to control the disease

Introduction. Diaphyseal tibial fractures account for approximately 1.9% of adult fractures. Several studies demonstrate a high proportion of diaphyseal tibial fractures have ipsilateral occult posterior malleolus fractures, this ranges from 22–92.3%. Materials and Methods. A retrospective review of a prospectively collected database was performed at Liverpool University Hospitals NHS Foundation Trust between 1/1/2013 and 9/11/2020. The inclusion criteria were patients over 16, with a diaphyseal tibial fracture and who underwent a CT. The articular fracture extension was categorised into either posterior malleolar (PM) or other fracture. Results. 764 fractures were analysed, 300 had a CT. There were 127 intra-articular fractures. 83 (65.4%) cases were PM and 44 were other fractures. On univariate analysis for PM fractures, fibular spiral (p=.016) fractures, no fibular fracture(p=.003), lateral direction of the tibial fracture (p=.04), female gender (p=.002), AO 42B1 (p=.033) and an increasing angle of tibial fracture. On multivariate regression analysis a high angle of tibia fracture was significant. Other fracture extensions were associated with no fibular fracture (p=.002), medial direction of tibia fracture (p=.004), female gender (p=.000), and AO 42A1 (p=.004), 42A2 (p=.029), 42B3 (p=.035) and 42C2 (p=.032). On multivariate analysis, the lateral direction of tibia fracture, and AO classification 42A1 and 42A2 were significant. Conclusions. Articular extension happened in 42.3%. A number of factors were associated with the extension, however multivariate analysis did not create a suitable prediction model. Nevertheless, rotational tibia fractures with a high angle of fracture should have further investigation with a CT

Aim. Since surgical site infections (SSIs) remain among the most common complications of orthopedic (trauma) surgery, there has been unwavering attention for potential predictors of a SSI. Specifically in surgical fields with a high complication rate, such as foot/ankle surgery, risk factor identification is of great importance. Recently, some studies have suggested environmental factors such as season to be of influence on the number of SSI. Specifically patients operated on in the summer are reported to have a higher incidence of SSIs, compared to other seasons. The aim of this study is to identify if “seasonality” is a significant predictor for SSI in a cohort of (trauma) surgical foot and ankle procedures. Method. This retrospective cohort study included all patients undergoing trauma related surgery (fracture fixation, arthrodesis, implant removal and tendon repair) of the lower leg, ankle and foot. Procedures were performed at a single Level 1 Trauma Center in the Netherlands between September 2015 until February 2019. Potential risk factors/ confounders for SSI were identified using univariate analysis (Chi-Square/Mann-Whitney U). Procedures were divided in two groups: 1) performed in summer (June, July or August), 2) not performed in summer (September-May). The number of SSIs was compared between the 2 groups, correcting for confounders, using multivariate regression. Results. A total of 605 procedures were included, largely fracture fixation (371, 61.2%). Patients were on average 46 y/o and the majority was male (369, 60.9%). The total number of SSIs was 34 (5.6%). Age, American Society of Anesthesiologists (ASA) classification (1–2 or 3–4) and open fractures were identified as possible predicting factors of SSI. No difference in SSIs was found between summer and other seasons, neither in univariate analysis (4 (3.2%) vs 30 (6.3%), p=0.271), nor when corrected for confounders. Moreover, in multivariate analysis only an ASA of >2 and an open fracture remained as independent predictors of SSI. Conclusions. No seasonality could be identified in the rate of SSI after trauma surgery of the lower leg, ankle and foot in this cohort. A possible explanation for this lack of effect could be the temperate oceanic climate of the Netherlands. Larger temperature and precipitation differences may also influence the incidence of SSIs. However, previous studies suggesting seasonality in SSIs might also be purely based on coincidence, especially when uncorrected for confounders

Aim. The purpose of this study is to analyze the demographic and microbiological variables of acute ankle infections posterior to ankle osteosynthesis and to determine the different characteristics of patients withE. cloacae infection. Method. A multicenter retrospective observational study (4 national hospitals) of acute post osteosynthesis infections of ankle fracture operated between 2015 and 2018 was implemented. The demographic and microbiological variables relating to the surgical intervention and the antibiotic treatment performed were collected. A descriptive assessment of all the variables and a univariate comparison between patients with E. cloacae infection and patients with alternative microorganism infections were performed. The SPSS v25 program for Windows was the choice for statistical analysis. Results. 71 Patients with an average age of 57 years were included, the majority being males (55%). 31% of patients were diabetic, 27% had vascular pathology, and 18.3% had a BMI greater than 35. Trimalleolar fracture was the most common in our study being 52%. 26.8% were open fractures. The microorganisms isolated were: 25% S. aureus, 22.5% E. cloacae and 22.5% polymicrobial. Accounting for polymicrobial infections, the presence of E. cloacae rises to 32%. In the univariate analysis, only significant differences were found in age (patients with E. cloacae infection were older) and the use of VAC therapy. Conclusions. In our series, higher percentages of E. cloacae infection were observed than those described in the literature. There are statistically significant differences in the variables of age and need for VAC therapy. The high incidence of E. cloacae infections suggests the vital importance of adapting antibiotic prophylaxis, ensuring the coverage of this microorganism

Introduction. Hip resurfacing arthroplasty (HRA) is an alternative to traditional total hip arthroplasty (THA) in young active patients. While comparative implant survival rates are well documented, there is a paucity of studies reporting the patient mortality rates associated with these procedures. The purpose of this study was to evaluate the mortality rates in patients age 55 years and younger who underwent HRA versus THA and to assess whether the type of operation was independently associated with mortality. Patients and Methods. The database of a single high-volume surgeon was reviewed for all consecutive patients age 55 years and younger who underwent hip arthroplasty between 2002 and 2010. HRA became available in the United States in 2006. This yielded 504 patients who had undergone HRA from 2006 to 2010 and 124 patients who had undergone a THA. Patient characteristics were collected from the electronic medical record including age, gender, body mass index, Charleston comorbidity index, smoking status, and primary diagnosis. Mortality was determined through a combination of electronic chart reviews, patient phone calls, and online obituary searches. Univariate analysis was performed to identify a survival difference between the two cohorts. Multivariable Cox-Regression analyses were used to determine whether the type of operation was independently associated with mortality. Results. The mean follow up for consecutive patients was 7 years (up to 11 years) in the HRA group and 8 years (up to 16 years) in the THA group. A total of 467 HRA patients (92%) and 105 THA patients (85%) were followed for a minimum of 5-years. 92% of the THA procedures were performed prior to the availability of HRA. There were 8 mortalities (1.6%) in the HRA cohort and 11 (8.9%) in the THA cohort, a statistically significant difference (p<0.001) on univariate analysis. Low mortality rates produced underpowered multivariate models. Conclusion. We have demonstrated that patients under age 55 who undergo HRA have a significantly lower mortality rate than those undergoing THA at mid-term follow-up. This is consistent with previously published large database studies. Such studies typically analyze large heterogeneous populations of patients and surgeons. Our study uniquely examined only patients age 55 or younger from a single high-volume surgeon, and we primarily reviewed THA performed prior to the availability of HRA as a surgical option. Thus, surgeon selection bias was largely eliminated. To our knowledge, this is the first single surgeon study comparing HRA and THA in terms of mortality

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

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

Shoulder arthroplasty has been performed by many years for the treatment of several conditions such as osteoarthritis, umeral head avascular necrosis and proximal umeral fractures following traumas. Surgical site infection (SSI) following shoulder arthroplasty remains a challenge, which increases morbidity including reoperations, implant removal, poor mobility, and raises extra medical costs. Identification of risk factors may help implementing adequate strategies to prevent infection. We aim to identify pre- and intra-operative risk factors associated with deep infections in shoulder arthroplasty. An age and sex-matched case control study was conducted to describe the prevalence rate, clinical and microbiological findings and to evaluate patient and surgical risk factors for shoulder arthroplasty-associated infections (SAIs), among 158 patients who underwent shoulder replacement surgery due to any reason, from 1988 to 2011 at a tertiary public university institution. To evaluate risk factors from SAI we performed uni- and multivariate analysis by multiple logistic regression. We analyzed 168 prosthetic shoulder replacement surgeries from 158 patients, with an overall infection rate of 9.5%, (16/168 cases). Gram-positive cocci and Gran-negative bacilli were equally isolated in 50% of cases, however the most common bacteria detected (18.8%) was Pseudomonas aeruginosa. Univariate analysis identified neither specific comorbidity nor pre-operative risk factors, but American Society of Anesthesiologists (ASA) score higher than 2 (odds ratio [OR] = 5.30, 95% confidence interval [CI] = 1.58 to 17.79; p=0,013) to be significant preoperative patient-related predisposing factor for SAI. On univariate analysis, the only surgery-related factor significantly associated with higher risk of SAIs was the presence of surgical haematoma (OR = 7.1, 95% CI = 1.1 to 46; p=0.04). On multivariate analysis ASA score higher than two (OR = 4.7, 95% CI = 1.3 to 16.9; p=0.01) was the only independent predictor for periprosthetic shoulder infection. This study identified unusual pathogens and confirmed previously patient-related known factors such as higher ASA score that predispose to SAIs