Abstract. Introduction. We aimed to compare the outcomes of elderly patients with periarticular distal femur or supracondylar periprosthetic fractures treated with either open reduction internal fixation or distal femoral replacement. Methods. A retrospective review of patients over 65 years with AO Type B and C fractures of the distal femur or Su type I and II periprosthetic fractures treated with either a DFR or ORIF was undertaken. Outcomes including Length of Stay, PROMs (Oxford Knee Score and EQ 5D), infection, union, mortality, complication and reoperation rates were assessed. Data on confounding variables were also collected for multivariate analysis. Patients below 65 years and extra articular fractures were excluded. Results. 23 patients (11 in DFR group and 12 in ORIF group) fulfilled inclusion criteria and were included in the analysis. There was no difference between the DFR and ORIF groups with respect to SDI, demographic variables, ASA grade, FCI, preoperative Hb and renal function. There was no difference in 30 day mortality, reoperation rates, 30 day readmission rates and LOS between the two groups. Mean follow up was 12.7 and 15.9 months respectively in the DFR and ORIF groups. At final follow up after accounting for all confounding variables on multivariate analysis, functional outcomes using OKS (adjusted mean: 29.5 vs 15.8) and Health related Quality of Life outcomes using EQ 5D (adjusted mean: 0.453 vs −0.07) were significantly better in the DFR group. Conclusion. DFR for periarticular and periprosthetic distal femoral fractures in the elderly are associated with better patient reported outcomes

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

Objectives. Post-infective arthritis is an important sequalae of septic arthritis(SA). While total knee arthroplasty(TKA) is an effective treatment for said arthritis, previous SA brings challenges for treatment planning. Using prospectively collected data from a cohort of patients with knee SA, this study aims to determine the proportion of patients requiring eventual TKA, and risk factors of developing prosthetic joint Infection(PJI). Methods. All cases of 1st episode knee SA from 01/01/2000 to 31/12/2020 were identified in the Auckland region. Patient records and NZJR records of all cases were searched to identify subsequent TKA. PJI following arthroplasty was identified using ICM criteria. Univariate and multivariate analysis was performed to determine risk factors for developing PJI. Results. 854 cases of native SA were identified. Of these, 71 (8.3%) progressed to TKA. Average time from completion of SA treatment to TKA was 3.8 years (SD 3.4). At an average follow-up of 7.8 years(1–19.6), 11(15.5%) developed PJI and required reoperation in the form of; DAIR (n =5), revision (n= 6). A further 4 were readmitted for superficial infections. Five-year and ten-year implant survival was 90.0% and 87.1%, significantly lower than average survival of TKA in the NZJR (97.3% at 5 years and 95.7% at 10). Average time between completion of SA treatment and TKA was 2.1 years in those developing PJI, vs 4.1 years in those who did not(p = 0.0019). 4.8% of cases developed PJI when TKA was performed >5 years after SA, compared with 20% risk of PJI within 5 years(p=0.16). Multivariate analysis showed no significant impact of pre-defined medical risk factors or demographic on outcomes. Conclusion. A significant percentage of patients required TKA following knee SA. Time lapsed from SA treatment completion to TKA is an important risk factor for developing PJI

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

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

The purpose of this study was to investigate the effectiveness of casting in achieving acceptable radiological parameters for unstable ankle injuries. This retrospective observational cohort study was conducted involving the retrieval of X-rays of all ankles taken over a 2 year period in an urban setting to investigate the radiological outcomes of cast management for unstable ankle fractures using four acceptable parameters measured on a single X- ray at union. The Picture Archiving and Communication System (PACS) was used, the X-rays were measured by a single observer. From the 1st of January 2020 to the 31st of December 2021, a total of 1043 ankle fractures were treated at the three hospitals with a male to female ratio of 1:1.7. Of the 628 unstable ankle injuries, 19% of patients were lost to follow up. 190 were managed conservatively with casts, requiring an average of 4 manipulations, with a malunion rate of 23.2%. Unstable ankle injuries that were treated surgically from the outset and those who failed conservative management and subsequently converted to surgery had a malunion rate of 8.1% and 11.0% respectively. Unstable ankle fractures pose a challenge with a high rate of radiological malunion, regardless of the treatment Casting surgery from the outset or converted to surgery, with rates of 23% and 8% and 11% respectively. In this multivariate analysis we found that conservative management was the only factor influencing the incidence of malunion, age, sex and type of fracture did not have a scientific significant influence

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

The primary objective is to compare revision rates for lumbar disc replacement (LDR) and fusion at the same or adjacent levels in Ontario, Canada. The secondary objectives include acute complications during hospitalization and in 30 days, and length of hospital stay. A population-based cohort study was conducted using health administrative databases including patients undergoing LDR or single level fusion between October 2005 to March 2018. Patients receiving LDR or fusion were identified using physician claims recorded in the Ontario Health Insurance Program database. Additional details of surgical procedure were obtained from the Canadian Institute for Health Information hospital discharge abstract. Primary outcome measured was presence of revision surgery in the lumbar spine defined as operation greater than 30 days from index procedure. Secondary outcomes were immediate/ acute complications within the first 30 days of index operation. A total of 42,024 patients were included. Mean follow up in the LDR and fusion groups were 2943 and 2301 days, respectively. The rates of revision surgery at the same or adjacent levels were 4.7% in the LDR group and 11.1% in the fusion group (P=.003). Multivariate analysis identified risk factors for revision surgery as being female, hypertension, and lower surgeon volume. More patients in the fusion group had dural tears (p<.001), while the LDR group had more “other” complications (p=.037). The LDR group had a longer mean hospital stay (p=.018). In this study population, the LDR group had lower rates of revision compared to the fusion group. Caution is needed in concluding its significance due to lack of clinical variables and possible differences in indications between LDR and posterior decompression and fusion

Introduction. Acetabular component loosening with associated bone loss is a challenge in revision hip arthroplasty. Trabecular Metal (TM) by Zimmer Biomet has been shown to have greater implant survivorship for all-cause acetabular revision in small cohort retrospective studies. Our study aims to review outcomes of acetabular TM implants locally. Method. This is a retrospective observational study using data from Auckland City and North Shore Hospitals from 1st of January 2010 to 31st of December 2020. Primary outcome is implant survivorship (re-revision acetabular surgery for any cause) demonstrated using Kaplan-Meier analysis. Secondary outcome is indication for index revision and re-revision surgery. Multivariate analysis used to identify statistically significant factors for re-revision surgery. Results. 225 cases used acetabular TM implants (shells and/or augments) over 10 years. Indications include aseptic loosening (63%), instability (15%) and infection (13%). Of these, 12% (n=28) had further re-revision for infection (54%) and instability (21%). Median time to re-revision was 156 days (range 11 – 2022). No cases of re-revision were due to failure of bony ingrowth or acetabular component loosening. Ethnicity, smoking status, and age were not risk factors for re-revision procedures. Additionally, previous prosthetic joint infection, ethnicity, sex and age were not significant risk factors for re-revision due to infection. Implant survivorship was 80% at 1 year, 71% at 5 years and 64% at 10 years. Discussion. Main indications for re-revision were infection and instability. Demographic factors and co-morbidities did not correlate with increased re-revision risk. Survivorship is poorer compared to cumulative survivorship reported by the New Zealand Joint Registry (NZJR). Explanations are multifactorial and possibly contributed by underestimation of true revision rates by registry data. Conclusions. We need to identify alternate causes for poorer survivorship and review the role of TM implants in acetabular revision within our specified population

This study aimed to identify the success rate of debridement, antibiotics and implant retention (DAIR) for prosthetic joint infection (PJI) in a large prospective cohort of patients undergoing total knee arthroplasty (TKA). The ability for different PJI classification systems to predict DAIR success was assessed. A prospective, multicenter study of PJIs occurring between July 2014 and December 2017 in 27 hospitals across Australia and New Zealand was performed. First time PJIs following primary TKA that were managed with DAIR were analyzed. DAIR success was defined as the patient being alive with documented absence of clinical or microbiological evidence of infection and no ongoing antibiotics for the index joint at 2-year follow-up. Multivariate analysis was performed for multiple PJI classification systems to assess their ability to predict DAIR success using their respective definitions of “early” PJI (Coventry ≤1 month, International Consensus Meeting ≤90 days or Auckland <1 year), or as hematogenous versus chronic PJI (Tsukayama). 189 PJIs were managed with DAIR, with an overall success rate of 45% (85/189). Early PJIs had a higher rate of DAIR success when analyzed according to the Coventry system (adjusted odds ratio = 3.85, p = 0.008), the ICM system (adjusted odds ratio = 3.08, p = 0.005) and the Auckland system (adjusted odds ratio = 2.60, p = 0.01). DAIR success was lower in both hematogenous (adjusted odds ratio = 0.36, p = 0.034) and chronic PJIs (adjusted odds ratio = 0.14, p = 0.003) occurring more than one year since the primary TKA. DAIR success is highest when performed in infections occurring within one year of the primary TKA. Late infections had a high DAIR failure rate irrespective of their classification as hematogenous or chronic. Time since primary is a useful predictor of DAIR success

Higher levels of socioeconomic deprivation have been associated with worse health outcomes. The influence of socioeconomic deprivation on patients undergoing periacetabular osteotomy (PAO) has not previously been investigated. A total of 217 patients (171 female, 46 male; median age 23.4 years) who underwent PAO by a single surgeon were identified. Patients were categorised into three groups according to their New Zealand Deprivation (NZDep) Index: minimal deprivation (NZDep Index 1–3, n=89), moderate deprivation (NZDep Index 4–6, n=94), and maximal deprivation (NZDep Index 7–10, n=34). The three groups were compared with respect to baseline variables, surgical details, complications, and pre-operative and two-year post-operative functional scores (including International Hip Outcome Tool (iHOT-12), EQ-5D quality of life score, and University of California Los Angeles (UCLA) activity score). Multivariate regression was undertaken to assess for the effect of NZDep Index on patient outcomes. Patients in the maximal deprivation group were more likely to be Māori (p<0.001) and have surgery in a public rather than a private hospital (p=0.004), while the minimal deprivation group demonstrated a lower BMI (p=0.005). There were otherwise no other significant differences in baseline variables, surgical details, complications, nor pre-operative or two-year post-operative functional scores between the three groups (all p>0.05). Multivariate analysis identified a higher NZDep Index to be independently predictive of a lower pre-operative UCLA activity score (p=0.014) and a higher two-year iHOT-12 score (p<0.001). Our results demonstrate an inequality in access to PAO, with patients exposed to higher levels of socioeconomic deprivation under-represented in our study population. When provided access to PAO, these vulnerable patients achieve significant functional improvement at least as great as patients with less socioeconomic deprivation. Initiatives to improve access to hip preservation care in socioeconomically deprived populations appear warranted

Intimate partner violence (IPV) causes significant morbidity and its unlikely to be reported compared to other forms of gender-based violence (GBV). For early detection, understanding Orthopaedic injuries from GBV is vital. This study assesses the pattern of musculoskeletal injuries from GBV and determines the factors associated with it. It is a retrospective observational study of patients aged ≥18 years, with GBV-related acute Orthopaedic injuries. Data was reviewed from January 2021 to December 2021, including, demographic information, soft tissue and bony injuries, relationship to assailant, substance abuse and the day and time of injury. Frequencies and percentages for categorical data were analysed. Chi-square test was used to calculate association. T-test was used to compare groups for continuous & categorical variables. Multivariate analysis was conducted to find the odds ratio and a p-value <0.05 was statistically significant. 138 patients were included, the mean age at presentation being 35.02 years (SD=11). 92.75% of GBV victims were females. Most were unemployed (66.7%). 30.43% (n-42) had a soft tissue injury; superficial laceration being the most common (23.1%), flexor tendon injury (10.87%), hand abscess (5.8%), and extensor tendon injury (5.07%). 71.02 % (n=98) sustained appendicular fractures. 51.45% (n=71) sustained upper limb fractures; distal radius fractures (10.86%) and distal 3rd ulnar fractures (9,42%). 19.57% (n=27) had lower limb fractures; 7.25% (n=10) had lateral malleolus ankle fractures. 63.7% (n=80) of cases were by an intimate partner on weekends (50.73%). 62.31% occurred between 16h00 and 0h00. 41.1% (n=65) reported alcohol abuse. 63.04% had surgery. GBV likely occurs in early middle-aged females by intimate partners influenced by alcohol over the weekends between 16h00 to 0h00. Distal radius/distal 3rd ulnar fractures are the most common bony injuries. Superficial wrist laceration is the commonest soft tissue injury. These findings may assist with early detection and intervention to prevent adverse outcomes in GBV

Prolonged length of stay (LOS) is a significant contributor to the variation in surgical health care costs and resource utilization after elective spine surgery. The primary goal of this study was to identify patient, surgical and institutional variables that influence LOS. The secondary objective is to examine variability in institutional practices among participating centers. This is a retrospective study of a prospectively multicentric followed cohort of patients enrolled in the CSORN between January 2015 and October 2020. A logistic regression model and bootstrapping method was used. A survey was sent to participating centers to assessed institutional level interventions in place to decrease LOS. Centers with LOS shorter than the median were compared to centers with LOS longer than the median. A total of 3734 patients were included (979 discectomies, 1102 laminectomies, 1653 fusions). The median LOS for discectomy, laminectomy and fusion were respectively 0.0 day (IQR 1.0), 1.0 day (IQR 2.0) and 4.0 days (IQR 2.0). Laminectomy group had the largest variability (SD=4.4, Range 0-133 days). For discectomy, predictors of LOS longer than 0 days were having less leg pain, higher ODI, symptoms duration over 2 years, open procedure, and AE (p< 0.05). Predictors of longer LOS than median of 1 day for laminectomy were increasing age, living alone, higher ODI, open procedures, longer operative time, and AEs (p< 0.05). For posterior instrumented fusion, predictors of longer LOS than median of 4 days were older age, living alone, more comorbidities, less back pain, higher ODI, using narcotics, longer operative time, open procedures, and AEs (p< 0.05). Ten centers (53%) had either ERAS or a standardized protocol aimed at reducing LOS. In this study stratifying individual patient and institutional level factors across Canada, several independent predictors were identified to enhance the understanding of LOS variability in common elective lumbar spine surgery. The current study provides an updated detailed analysis of the ongoing Canadian efforts in the implementation of multimodal ERAS care pathways. Future studies should explore multivariate analysis in institutional factors and the influence of preoperative patient education on LOS

Introduction. The surgical management of late PJI was usually done in two stages with the placement of a temporary cement spacer. The development of one-stage surgical care raises questions about the two-stage strategy. The objectives of this study are to identify the complications related to the presence of the cement spacer within a two-stage strategy. The septic recurrence rate is also evaluated after a minimum follow-up of two years. Material and methods. Medical files of 208 patients (101 knees and 107 hips) who underwent a two-stage revision for late PJI prosthesis infection were retrospectively reviewed. Antibiotic loaded articulated homemade cement spacers were used. Second stage was usually planned on average 4 to 6 weeks after the first stage. Patients were allowed to walk without loading. The success rate was defined as the absence of septic recurrence after a minimum follow-up of two years. Descriptive statistics and uni- and multivariate analysis were conducted. Results. The spacers were left in place for an average of 42 days for the knees and 30 days for the hips. Six patients (3%) died before performing the second stage. Hip spacers were associated with 8 fractures for only one observed in the knee (4%). Spacer dislocation (11%) was observed in 23 cases (13 for the hip and 10 for the knee respectively). Treatment failure with recurrence of the infection within 2 years was observed in 26 patients (12%). Resistance to the antibiotic present in the cement was found in one third of infectious failures. The presence of a prior cemented prosthesis was significantly associated with the presence of a germ resistant to gentamicin and the persistence of the germ at the second stage. However, it was not associated with failure at two years. Discussion. the two-stage management of PJI is associated with a non-negligible mortality rate before the second stage, rarely reported in studies. The presence of an initially cemented prosthesis is associated with the presence of germs resistant to the antibiotic contained in the cement and exposes to the persistence of the resistant germ at the second stage. Spacer fractures are observed more at the hip, but less frequently than in previous reports, while dislocations are observed at both the hip and the knee, particularly due to loss of tibial fixation in this area. These observations are all arguments for further consideration of revision surgery in 1 stage

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

Aim. To analyse the prevalence of culture negative periprosthetic joint infections (PJI) when adequate culture techniques are applied, and to evaluate the outcome of patients who were treated with antibiotics for a culture negative PJI versus those in whom treatment was withheld. Method. A multicenter observational study in which acute and chronic PJIs diagnosed between 2013 and 2018 were analyzed. Culture negative PJIs were diagnosed according to the MSIS, ICM and EBJIS definitions. Results. Out of the 1553 acute PJIs, none were culture negative. Out of the 1556 chronic PJIs, 70 were culture negative (4.7%) and included for further analysis. A total of 36 were treated with antibiotics (51%). After two years of follow-up, no infections occurred in patients in whom antibiotic treatment was withheld, but prosthesis extraction by any cause was observed more often in the no antibiotic group compared to the antibiotic group (32.4% versus 8.3%, P 0.012), especially in the absence of metallosis. Antibiotic treatment was the only independent predictor of prosthesis retention in the multivariate analysis (95% CI 0.15, 0.03 – 0.70). Conclusions. When adequate culture techniques are applied, the incidence of culture negative PJIs is low. If diagnosed, antibiotic treatment should be administered

Aim. Infection is one of the worst complications following total joint arthroplasty, which is often associated with significant morbidity. Currently, due to the global burden of multidrug-resistant Gram-negative bacteria (MDR-GNB) infections, few multicentre studies have described a microbiological shift from Gram-positive cocci (GPC) towards MDR-GNB PJI (prosthetic joint infection). Additionally, the emergence of MDR-GNB impacts the therapeutic options and may increase the rate of PJI treatment failure. The purpose of the present study was to describe the predisposing factors associated to failure of treatment in an orthopaedic reference hospital in Brazil from 2014 through 2019. Method. Retrospective case-control analysis of patients treated for MDR-GNB PJI over a five-year period. Data were collected from medical, surgical and laboratory records. PJI were defined according the current MSIS criteria. MDR was defined as non-susceptibility to at least one agent in three or more antimicrobial categories. Patients with PJI with at least two positive tissue cultures for MDR-GNB were selected. The control group was patient with PJI caused by multisensitive organism (GNB or GPC). Absence of signs and symptoms of infection during the follow-up period was defined as cure. Definition of failure: death, need for another course of antibiotic, or the need for another surgical procedure to control the infectious site (relapse). Results. A total of 104 patients were selected, 59 patients in the MDR-GNB PJI group and 44 in the control group. Two outcomes were compared: cure or failure. The overall 1-year survival rate was 65.3% with the median survival time being 207.08 days. In the MDR-BGN infection group the 1-year survival rate was 59.3% and the average time of survival was 141.14 days. In contrast, in the Control group the 1-year survival rate was 73.8% with an average survival time of 230.29 days (p = 0.023). HR: 2.447, IC 1.099–5.448. The independent variables in the multivariate analysis associated to treatment failure were MDR-BGN infection (p = 0.023) HR 2,447 IC 1,099 –5,448, revision surgery (p = 0.042) HR 2,027 IC: 2,027–4,061, presence of comorbidities (p = 0.048) HR 2,508 IC: 0,972- 6,469 and previous antimicrobial use in the last 3 months (p = 0.022). HR 2,132 IC: 1,096- 4,149. Conclusions. GNB-MDR PJI increases approximately 2.5 times the chance of unfavourable outcome such as death and infectious relapse compared to infections with other multisensitive microorganism

Acute Haematogenous Osteomyelitis (AHO) remains a cause of severe illness among children. Contemporary research aims to identify predictors of acute and chronic complications. Trends in C-reactive protein (CRP) following treatment initiation may predict disease course. We have sought to identify factors associated with acute and chronic complications in the New Zealand population. A retrospective review of all patients <16 years with presumed AHO presenting to a tertiary referral centre between 2008–2018 was performed. Multivariate was analysis used to identify factors associated with an acute or chronic complication. An “acute” complication was defined as need for two or more surgical procedures, hospital stay longer than 14-days, or recurrence despite IV antibiotics. A “chronic” complication was defined as growth or limb length discrepancy, avascular necrosis, chronic osteomyelitis, pathological fracture, frozen joint or dislocation. 151 cases met inclusion criteria. The median age was 8 years (69.5% male). Within this cohort, 53 (34%) experienced an acute complication and 18 (12%) a chronic complication. Regression analysis showed that contiguous disease, delayed presentation, and failure to reduce CRP by 50% at day 4/5 predicted an acutely complicated disease course. Chronic complication was predicted by need for surgical management and failed CRP reduction by 50% at day 4/5. We conclude that CRP trends over 96 hours following commencement of treatment differentiate patients with AHO likely to experience severe disease

Outcomes following carpal tunnel release are generally favorable. Understanding factors that contribute to inferior outcomes may allow for strategies targeted at improving results in these patients. Our purpose was to determine if patients' underlying personality traits, specifically resiliency and catastrophization, impact their post-operative outcomes following carpal tunnel release. A prospective case series was performed. Based on our power analysis, 102 patients were recruited. Patients completed written consent, the Boston Carpal Tunnel Questionnaire (BCTQ), the Pain Catastrophizing Scale (PCS) and the Brief Resiliency Scale (BRS). A single surgeon, or his resident under supervision, then performed an open carpal release under local anaesthetic. Our primary outcome measure was a repeat BCTQ at three- and six-months. Univariate and multivariate analysis was performed to assess the correlation between PCS and BRS scores and final BCTQ scores. Forty-three and sixty-three participants completed the BCTQ at three and six months respectively. All patients showed improvement in their symptoms (p = 0.001). There was no correlation between patients PCS or BRS and the amount of improvement. There was also no correlation between PCS or BRS and the patients' raw scores at baseline or follow-up. Patients self-assessed resiliency and degree of pain catastrophization has no correlation with the amount of improvement they have three or six months post-operatively. Most patients improved following carpal tunnel release, and patients with low resiliency and high levels of pain catastrophization should expect comparable outcomes to patients without these features