The aim of this study was to determine the long term 20 year survival and outcomes of high tibial osteotomy (HTO). 100 consecutive subjects underwent HTO under the care of a single surgeon between 2000 and 2002, consented to participation in a prospective study and completed preoperative WOMAC scores. Subjects were reviewed at 10 years, and again at a minimum of 20 years after surgery. PROMS included further surgery, WOMAC scores, Oxford Knee Score (OHS), KOOS, and EQ-5D, and satisfaction with surgery. 20 year survival was assessed with Kaplan-Meir analysis, and failure defined as proceeding to subsequent knee arthroplasty. The mean age at HTO was 50 years (range 26-66), and 72% were males. The 5, 10, and 20 year survival of the HTO was 88%, 76%, 43% respectively. On multiple regression analysis HTO failure was associated with poor preoperative WOMAC score of 45 or less (HR 3.2, 95% CI 1.7-6.0, p=0.001), age at surgery of 55 or more (HR 2.3, 95% CI 1.3-4.0, p=0.004), and obesity (HR 1.9, 95% CI 1.1-3.4, p=0.023). In patients who met all criteria of preoperative WOMAC score of 45 or less, age <55 years and body mass index of <30 HTO survival was 100%, 94%, and 59% at 5, 10 and 20 years respectively. Of those who had not proceeded to TKA the mean Oxford Score was 40, KOOS Pain score was 91 and KOOS function score was 97. 97% reported they were satisfied with the surgery and 88% would have the same surgery again under the same circumstances. At 20 years after HTO 43% had not proceeded to knee arthroplasty, and were continuing to demonstrate high subjective scores and satisfaction with surgery. HTO survival was higher in those under 55 years, with BMI <30 and baseline WOMAC score of >45 at 59% HTO survival over 20 years. HTO may be considered a viable procedure to delay premature knee arthroplasty in carefully selected subjects

Cementless fixation is an alternative to cemented unicompartmental knee replacement (UKR), with several advantages over cementation. This study reports on the 15-year survival and 10-year clinical outcomes of the cementless Oxford unicompartmental knee replacement (OUKR). This prospective study describes the clinical outcomes and survival of first 693 consecutive cementless medial OUKRs implanted in New Zealand. The sixteen-year survival was 89.2%, with forty-six knees being revised. The commonest reason for revision was progression of arthritis, which occurred in twenty-three knees, followed by primary dislocation of the bearing, which occurred in nine knees. There were two bearing dislocations secondary to trauma and a ruptured ACL, and two tibial plateau fractures. There were four revisions for polyethylene wear. There were four revisions for aseptic tibial loosening, and one revision for impingement secondary to overhang of the tibial component. There was only one revision for deep infection and one revision where the indication was not stated. The mean OKS improved from 23.3 (7.4 SD) to 40.59 (SD 6.8) at a mean follow-up of sixteen years. In conclusion, the cementless OUKR is a safe and reproducible procedure with excellent sixteen-year survival and clinical outcomes

Introduction. Despite the advances in adjuvant chemotherapy and surgical techniques, the diagnosis of a bone tumour still carries with it a significant risk of mortality. This study investigates factors affecting survival, in patients treated for malignant tumours of bone using Endoprosthetic replacement (EPR). Methods. Our tertiary referral musculoskeletal tumour unit has taken referrals over 40 years. Electronic patient records have been prospectively kept on all patients seen since 1986 and data has been entered retrospectively for patients seen between 1966 and 1986. A consecutive series of 1264 patients underwent endoprosthetic reconstruction; after 158 patients were excluded, 1106 patients were left in the study group. Factors including diagnosis, size of tumour, surgical margins, percentage tumour necrosis following chemotherapy, tumour site, local recurrence, decade of reconstruction, fracture and post-operative deep infection were analysed. Results. Overall population survival was 58.4% at 5 years, 50.5% at 10 years and 44.6% at 20 years. Significant prognostic factors on cox-regression analysis included locally recurrent disease (p<0.001), metastatic disease (p<0.001), chemotherapy (p<0.001), percentage tumour necrosis after chemotherapy (p=0.001), tumour size (p<0.001), post-operative surgical margin (p<0.001), fracture (p<0.001) and post-operative deep infection (p=0.05). Univariate analysis showed proximal femoral site (p=0.01) and EPRs after 1991 (p=0.05) were significant factors. Patients diagnosed with a deep infection within 2.5 years from implantation had 63.2% 10 year survival, compared to 49.4% in the non infected group. When stratified by diagnosis this was significant in patients with myeloma (p=0.01) and a showed strong trend in those with osteosarcoma (p=0.1). Trends towards better survival with Staphylococcal infections (p=0.2) were not demonstrated with other organisms. Discussion and conclusion. Several known prognostic factors were demonstrated for malignant bone tumours but there was evidence for increased survival after deep post-operative infection. The authors feel the results of this study and other recent evidence warrant further investigation

Abstract. Cemented total hip arthroplasty (THA) in the younger patient has historically been associated with higher wear and revision rates. We carried out a retrospective study of a prospectively collected database of patients at Wrightington hospital undergoing cemented THA under 55 years of age to determine acetabular wear and revision rates. Between August 2005 and December 2021 a cohort of 110 patients, 56 males and 54 females, underwent Cemented Total Hip Replacement through a posterior approach. Mean age at operation was 50yrs (35–55). The mean follow up was 6 years 9 months (0–16 years). 3 patients were lost to follow-up. Of the remaining 107 patients, Conventional and cross lined polyethylene were used in 54 and 53 patients respectively. Ceramic heads were used in 102 patients. 22.225mm and 28mm heads were used in 60 and 47 patients respectively. Clinical outcomes were assessed by Merle d'Aubigne and Postel scores which showed significant functional improvement. Linear wear was measured on plain radiographs using TRAUMA CAD and cup loosening was assessed by classification of Hodgkinson et al. No cases were revised during the observed follow up period. The mean wear rate in conventional and crosslinked polyethylene cups were 2.31mm (0.1–4.6) and 1.02mm (0.1–2.6) respectively. Cemented THA with both conventional and crosslinked polyethylene provides excellent survival rates in adults under the age of 55 years and crosslinked polyethylene may further improve these results due to improved wear rates

Several different algorithms attempt to estimate life expectancy for patients with metastatic spine disease. The Skeletal Oncology Research Group (SORG) has recently developed a nomogram to estimate survival of patients with metastatic spine disease. Whilst the use of the SORG nomogram has been validated in the international context, there has been no study to date that validates the use of the SORG nomogram in New Zealand. This study aimed to validate the use of the SORG nomogram in Aotearoa New Zealand. We collected data on 100 patients who presented to Waikato Hospital with a diagnosis of spinal metastatic disease. The SORG nomogram gave survival probabilities for each patient at each time point. Receiver Operating Characteristic (ROC) Area Under Curve (AUC) analysis was performed to assess the predictive accuracy of the SORG score. A calibration curve was also performed, and Brier scores calculated. A multivariate Cox regression analysis was performed. The SORG score was correlated with 30 day (AUC = 0.72) and 90-day mortality (AUC = 0.71). The correlation between the SORG score and 90-day mortality was weaker (AUC = 0.69). Using this method, the nomogram was correct for 79 (79%) patients at 30-days, 59 patients (59%) at 90-days, and 42 patients (42%) at 365-days. Calibration curves demonstrated poor forecasting of the SORG nomogram at 30 (Brier score = 0.65) and 365 days (Brier score = 0.33). The calibration curve demonstrated borderline forecasting of the SORG nomogram at 90 days (Brier score = 0.28). Several components of the SORG nomogram were not found to be correlated with mortality. In this New Zealand cohort the SORG nomogram demonstrated only acceptable discrimination at best in predicting life 30-, 90- or 356-day mortality in patients with metastatic spinal disease

Population-based studies from the United States have reported that sarcoma patients living in rural areas or belonging to lower socioeconomic classes experience worse overall survival; however, the evidence is not clear for universal healthcare systems where financial resources should theoretically not affect access to standard of care. The purpose of this study was to determine the survival outcomes of soft-tissue sarcoma (STS) patients treated in Ontario, Canada over 23 years and determine if the patient's geographic location or income quintile are associated with survival. We performed a population-based cohort study using linked administrative databases of patients diagnosed with STS between 1993 – 2015. The Kaplan-Meier method was used to estimate 2, 5, 10, 15 and 20-year survival stratified by age, stage and location of tumor. We estimated survival outcomes based on the patient's geographic location and income quintile. The Log-Rank test was used to detect significant differences between groups. If groups were significantly different, a Cox proportional hazards model was used to test for interaction effects with other patient variables. We identified 8,896 patients with biopsy-confirmed STS during the 23-year study period. Overall survival following STS diagnosis was 70% at 2 years, 59% at 5 years, 50% at 10 years, 43% at 15 years, and 38% at 20 years. Living in a rural location (p=0.0028) and belonging to the lowest income quintile (p<0.0001) were independently associated with lower overall survival following STS diagnosis. These findings were robust to tests of interaction with each other, age, gender, location of tumor and stage of disease. This population-based cohort study of 8,896 STS patients treated in Ontario, Canada over 23 years reveals that patients living in a rural area and belonging to the lowest income quintile are at risk for decreased survival following STS diagnosis. We extend previous STS survival reporting by providing 15 and 20-year survival outcomes stratified by age, stage, and tumor location

Introduction. Innovations in surgical robotics and navigation have significantly improved implant placement accuracy in total knee arthroplasty (TKA). However, many comparative studies have not been shown to substantially improve revision rates or other clinical outcome scores. We conducted a simulation study based on the reported distribution of patient-specific characteristics and estimated potential effect of coronal plane alignment (CPA) on risk of revision to evaluate the hypothesis that most published study designs in this area have been too underpowered to detect improvements in revision rates. Methods. To model previously reported studies, we generated a series of simulated TKA patient populations, assigning each patient a set of patient-specific factors (age at index surgery, BMI, and sex (Fig.1a)), as well as one surgeon-controlled factor (CPA) (Fig.1b) based on registry data and published literature. We modelled the survival probability for an individual patient at time t as a Gaussian function (exp[-(t/(k∗τ. max. )). 2. ]), where τ. max. (99.5 years) is selected to ensure the mean survival probability of the patient population matched 92% at 15 years. The value of k was adjusted for simulated patients within a range of 0 to 1 as a function of their patient and surgeon-specific factors (Fig.2). To evaluate power associated with a study design, we ran a Monte Carlo simulation generating 10,000 simulated populations of ten different cohort sizes. We divided the patient population into two groups: one group was assigned CPAs governed by the precision of a navigated/robotic approach (σ=1.5°), and the other CPAs governed by the precision of a conventional approach (σ=3°). We then simulated the time to failure for each patient, computed the corresponding Kaplan-Meier survival curves, and applied a Log-Rank test to each study to test for statistical difference. From the 10,000 simulations associated with each cohort size, we determined the percentage of simulated studies that found a statistically significant difference at each time point. Results. Figure 3 shows a contour plot illustrating the probability that a survival analysis with a specific study design would find statistical significance between the conventional and navigated/robotic patient groups. Entries from recently published literature are overlaid for context. No studies achieved statistical significance (p<0.05). Discussion. The effectiveness of navigated/robotic surgery is one of the most controversial debates in orthopedic surgery. The results from this simulation suggest that most revision studies aiming to settle this debate are likely significantly underpowered, falling below the normal 80% threshold. Limitations of this analysis include using only a single surgeon-controlled variable in the survival simulation, and only a single precision for the navigated/robotic approaches. Further studies will include more implant-related risk factors and a wider range of precisions for navigated/robotic procedures. Based on this simulation, it appears the effect size afforded by navigated/robotic surgeries on revision rates in TKA surgery is too small to recommend broad application, especially since adoption could involve added costs and unforeseen risks associated with novelty. Clinically, it may be beneficial to examine the use of robotics/navigation on high-risk patients, where studies are likely to have higher power due to larger effect sizes. For any figures or tables, please contact the authors directly

The management of primary malignant bone tumors with metastatic disease at presentation remains a challenge. While surgical resection has been shown to improve overall survival among patients with non-metastatic malignant bone tumors, current evidence regarding the utility of surgery in improving overall survival in metastatic patients remains limited. The 2004–2016 National Cancer Database (NCDB) was queried using International Classification of Diseases 3rd Edition (ICD-O-3) topographical codes to identify patients with primary malignant bone tumors of the extremities (C40.0-C40.3, C40.8 and C40.9) and/or pelvis (C41.4). Patients with malignant bone tumors of the axial skeleton (head/skull, trunk and spinal column) were excluded, as these cases are not routinely encountered and/or managed by orthopaedic oncologists. Histological codes were used to categorize the tumors into the following groups - osteosarcomas, chondrosarcomas, and Ewing sarcomas. Patients who were classified as stage I, II or III, based on American Joint Commission of Cancer (AJCC) guidelines, were excluded. Only patients with metastatic disease at presentation were included in the final study sample. The study sample was divided into two distinct groups – those who underwent surgical resection of the primary tumors vs. those who did not receive any surgery of the primary tumor. Kaplan-Meier survival analysis was used to report unadjusted 5-year overall survival rates between patients who underwent surgical resection of the primary tumor, compared to those who did not. Multi-variate Cox regression analyses were used to assess whether undergoing surgical resection of the primary tumor was associated with improved overall survival, after controlling for differences in baseline demographics, tumor characteristics (grade, location, histological type and tumor size), and treatment patterns (underwent metastatectomy of distal and/or regional sites, positive vs. negative surgical margins, use of radiation therapy and/or chemotherapy). Additional sensitivity analyses, stratified by histologic type for osteosarcomas, chondrosarcomas and Ewing sarcomas, were used to assess prognostic factors for overall survival. A total of 2,288 primary malignant bone tumors (1,121 osteosarcomas, 345 chondrosarcomas, and 822 Ewing sarcomas) with metastatic disease at presentation were included – out of which 1,066 (46.0%) underwent a surgical resection of the primary site. Overall 5-year survival rates, on unadjusted Kaplan-Meier log-rank analysis, were significantly better for individuals who underwent surgical resection vs. those who did not receive any surgery (31.7% vs. 17.3%; p<0.001). After controlling for differences in baseline demographics, tumor characteristics and treatment patterns, undergoing surgical resection of primary site was associated with a reduced overall mortality (HR 0.42 [95% CI 0.36–0.49]; p<0.001). Undergoing metastectomy (HR 0.92 [95% CI 0.81–1.05]; p=0.235) was not associated with a significant improvement in overall survival. On stratified analysis, radiation therapy was associated with improved overall survival for Ewing Sarcoma (HR 0.71 [95% CI 0.57–0.88]; p=0.002), but not for osteosarcoma (HR 1.14 [95% CI 0.91–1.43]; p=0.643) or chondrosarcoma (HR 1.08 [95 % CI 0.78–1.50]; p=0.643). Chemotherapy was associated with improved overall survival for osteosarcoma (HR 0.50 [95% CI 0.39–0.64]; p<0.001) and chondrosarcoma (HR 0.62 [95% CI 0.45–0.85]; p=0.003), but not Ewing sarcoma (HR 0.79 [95% CI 0.46–1.35]; p=0.385). Surgical resection of the primary site significantly improves overall survival for primary malignant bone tumors with metastatic disease at presentation. Physicians should strongly consider surgical resection of the primary tumor, with adjunct systemic and/or radiation therapy (dependent on tumor histology), in patients presenting with metastatic disease at presentation

INTRODUCTION. Total knee arthroplasty (TKA) is considered a highly successful procedure. Survival rates of more than 90% after 10 years are generally reported. However, complications and revisions may still occur for many reasons, and some of them may be related to the operative technique. Computer assistance has been suggested to improve the accuracy of implantation of a TKA (Jenny 2005). Short term results are still controversial (Roberts 2015). However, few long term results have been documented (Song 2016). The present study was designed to evaluate the long-term (more than 10 years) results of a TKA which was routinely implanted with help of a non-image based navigation system. The 5- to 8-year of this specific TKA has already been documented (Jenny 2013). The hypothesis of this study will be that the 10 year survival rate of this TKA will be improved in comparison to historical papers when analyzing survival rates and knee function as evaluated by the Knee Society Score (KSS). MATERIAL AND METHODS. All patients operated on between 2001 and 2004 for implantation of a navigated TKA were eligible for this study. Usual demographic and peri-operative items have been record. All patients were prospectively followed with clinical and radiological examination. All patients were contacted after the 10 year follow-up for repeat clinical and radiological examination (KSS, Oxford knee questionnaire and knee plain X-rays). Patients who did not return were interviewed by phone call. For patients lost of follow-up, family or general practitioner was contacted to obtain relevant information about prosthesis survival. Survival curve was plotted according to Kaplan-Meier. RESULTS. 247 TKAs were implanted during the study time-frame. 225 cases had an optimal lower limb axis (HKA angle between 177° and 183°) after TKA (91%). Final follow-up (including death or revision) was obtained for 200 cases (81%). Clinical status after 10 years was obtained for 146 cases (59%) (KSS, 102 cases – Oxford questionnaire, 146 cases – radiologic evaluation, 94 cases). 4 prosthetic revisions were performed for mechanical reasons during the follow-up time (1%). The 10 year survival rate was 98%. The mean KSS was 188 points. The mean Oxford score was 55 points. No component was considered loose at the final radiographic evaluation. No polyethylene wear was detected at the final radiographic evaluation. DISCUSSION. This study confirms our initial hypothesis, namely quite satisfactory results of navigated implanted TKA after more than 10 years. Navigation, whose precision is no longer to be demonstrated, probably contributed to the quality of the results. A more consistent anatomical reconstruction and ligamentous balance of the knee should lead to more consistent survival of the TKA. Other authors did observe similar results (Baumbach 2016). However, superiority of navigated TKA in comparison to conventional implanted TKA is difficult to prove because of the subtle differences expected in mostly underpowered studies. Longer term follow-up may be required

Chronic massive irreparable rotator cuff tears represent a treatment challenge and the optimal surgical technique remains controversial. Superior capsular reconstruction (SCR) has been proposed as a means to provide superior stability to the glenohumeral joint, thus facilitating restoration of shoulder function. However, despite the growing use of SCR there is a paucity of data evaluating the outcomes when performed using a dermal allograft. The purpose of this study was to (1) report the overall survival rate (reoperation and clinical failure) of SCR (2) evaluate for pre-operative factors predicting reoperation and clinical failure. From January 1, 2015 to November 31, 2017, 65 patients were diagnosed with irreparable rotator cuff tears and consented for a superior capsular reconstruction. These surgeries were performed by 6 surgeons, all fellowship trained in either sports or shoulder and elbow fellowships. Outcomes were graded as excellent, satisfactory, or unsatisfactory using the modified Neer scale. An unsatisfactory result was defined as a clinical “failure”. The Kaplan-Meier survival models were created to analyze reoperation-free and failure-free survival for the entire group. The reconstruction was performed using a dermal allograft. There were 31 patients excluded due to insufficient follow-up (< 6 months), leaving 34 included in this study. The mean follow-up was 12 months (range, 6–23). The average number of prior surgeries was 0.91 (range, 0–5), with 52.9% of patients receiving a prior rotator cuff repair and 38.2% of patients with a prior non-rotator cuff arthroscopy procedure. The one and two-year survival-free of surgery was 64% and 44% and the one and two-year survival free of failure was 34% and 16% following SCR, respectively. For the patients that underwent a reoperation, 62.5% (n= 5/8) underwent reverse shoulder replacements, 25% (n= 2/8) latissimus dorsi tendon transfers, and 12.5% (n= 1/8) a diagnostic arthroscopy. The average period between the primary and revision surgery was 10.2 months (range, 2.1–18.5). All but two patients (75%, n= 6/8) had at least one surgery prior to the SCR. There were 14/34 (41.2%) patients who experienced pain, weakness, and restricted range of motion. These patients were defined as clinical failures with an unsatisfactory grading on Neer's criteria. Previous surgery predicted reoperation (80% vs 43%, p = 0.03). Female gender predicted clinical failure (100% vs 43%, p < 0 .01). Superior Capsule Reconstruction performed for large to massive rotator cuff tears has a high rate of persistent pain and limited function leading to clinical failure in 65% (n= 22/34) of patients. The rate of failure is increased in revision cases, female gender and increased Goutallier fatty infiltration of the infraspinatus. Narrowed indications are recommended given the surgical complexity and high rate of early failure

Increased femoral head size reduces the rate of dislocation after total hip arthroplasty (THA). With the introduction of highly crosslinked polyethylene (HXLPE) liners in THA there has been a trend towards using larger size femoral heads in relatively smaller cup sizes, theoretically increasing the risk of liner fracture, wear, or aseptic loosening. Short to medium follow-up studies have not demonstrated a negative effect of using thinner HXLPE liners. However, there is concern that these thinner liners may prematurely fail in the long-term, especially in those with thinner liners. The aim of this study was to evaluate the long-term survival and revision rates of HXLPE liners in primary THA, as well as the effect of liner thickness on these outcomes. We hypothesized that there would be no significant differences between the different liner thicknesses. We performed a retrospective database analysis from a single center of all primary total hip replacements using HXLPE liners from 2010 and earlier, including all femoral head sizes. All procedures were performed by fellowship trained arthroplasty surgeons. Patient characteristics, implant details including liner thickness, death, and revisions (all causes) were recorded. Patients were grouped for analysis for each millimeter of PE thickness (e.g. 4.0-4.9mm, 5.0-5.9mm). Kaplan-Meier survival estimates were estimated with all-cause and aseptic revisions as the endpoints. A total of 2354 patients (2584 hips) were included (mean age 64.3 years, min-max 19-96). Mean BMI was 29.0 and 47.6% was female. Mean follow-up was 13.2 years (range 11.0-18.8). Liner thickness varied from 4.9 to 12.7 mm. Seven patients had a liner thickness <5.0mm and 859 had a liner thickness of <6.0mm. Head sizes were 28mm (n=85, 3.3%), 32mm (n=1214, 47.0%), 36mm (n=1176, 45.5%), and 40mm (n=109, 4.2%), and 98.4% were metal heads. There were 101 revisions, and in 78 of these cases the liner was revised. Reason for revision was instability/dislocation (n=34), pseudotumor/aseptic lymphocyte-dominant vasculitis associated lesion (n=18), fracture (n=17), early loosening (n=11), infection (n=7), aseptic loosening (n=4), and other (n=10). When grouped by liner thickness, there were no significant differences between the groups when looking at all-cause revision (p=0.112) or aseptic revision (p=0.116). In our cohort, there were no significant differences in all-cause or aseptic revisions between any of the liner thickness groups at long-term follow-up. Our results indicate that using thinner HXPE liners to maximize femoral head size in THA does not lead to increased complications or liner failures at medium to long term follow-up. As such, orthopedic surgeons can consider the use of larger heads at the cost of liner thickness a safe practice to reduce the risk of dislocation after THA when using HXLPE liners

Background. As life expectancy increases, the number of octogenarians requiring primary and revision total knee arthroplasty (TKA) is increasing. Recently, primary TKA has become a common treatment option in octogenarians. However, surgeons are still hesitant about performing revision TKA on octogenarians because of concerning about risk- and cost-benefit. The purpose of this study was to investigate postoperative complications and mid-term survival in octogenarians following primary and revision total knee arthroplasty (TKA). Methods. We retrospectively reviewed 231 primary TKAs and 41 revision TKAs performed on octogenarians between 2000 and 2016. The mean age was 81.9 for primary TKA and 82.3 for revision TKA (p=0.310). The American Society of Anesthesiologists (ASA) score was not different, but the age-adjusted Charlson comorbidity index was higher in revision TKA (4.4 vs. 4.8, p=0.003). The mean follow-up period did not differ (3.8 vs. 3.5 years, p=0.451). The WOMAC scores and range of motion (ROM) were evaluated. The incidence of postoperative complication and survival rate (end point; death determined by telephone or mail communication with patient or family) were investigated. Results. The postoperative WOMAC and ROM were better in primary TKA (33.1 vs. 47.2, p<0.001; 128.9° vs. 113.6°, p<0.001). The most common postoperative complication was delirium in both groups (7.4% vs. 14.6%, p=0.131). There were no differences in the specific complication rates between the two groups. The 5- and 10-year survival rates were 87.2% and 62.9%, respectively, in primary TKA and 82.1% and 42.2%, respectively, in revision TKA (p=0.017). Conclusions. Both primary and revision TKAs are viable options for octogenarians when considering the clinical results and mid-term survival. Delirium needs to be managed appropriately as the most common complication in both primary and revision TKAs for octogenarians

Aim. Staphylococcus aureus (SA) can cause various infections and is associated with high morbidity and mortality rates of up to 40%. Antibiotic treatment often fails to eradicate SA infections even if the causative strain has been tested susceptible in vitro. The mechanisms leading to this persistence is still largely unknown. In our work, we to reveal SA interactions with host cells that allow SA to persist at the site of infection. Method. We established a sampling workflow to receive tissue samples from patients requiring surgical debridement due to SA bone-and joint or soft-tissue infections. We developed a multiplex immunofluorescent staining protocol which allowed us to stain for SA, leukocytes, neutrophils, macrophages, B-cells, T-cells, DAPI and cytoplasmatic marker on the same sample slide. Further, distance of SA to cell nuclei was measured. Interaction of immune cells and SA on a single cell level was investigated with high-resolution 3D microscopy. We then validated our findings applying fluorescence-activated cell sorting (FACS) on digested patient samples. Finally, we aimed to reproduce our ex vivo patient results in an in vitro co-culture model of primary macrophages and clinical SA strains, where we used live cell microscopy and high-resolution microscopy to visualize SA-immune cell interactions and a gentamicin protection assay to assess viability of SA. Results. Here, we revealed that CD68+ macrophages were the immune cells closest to SA with a mean distance of 56μm (SD=36.4μm). Counting the amount of SA, we found in total >7000 single SA in nine patients. Two-thirds of SA were located intracellularly. Two-thirds of the affected immune cells with intracellular SA were macrophages. The distribution of intra- to extracellular SA was independent of ongoing antibiotic therapy and underlying infection type. FACS confirmed these findings. In our co-culture model, intracellular SA remained alive for the whole observation period of eight hours and resided in RAB5+ early phagosomes. Conclusions. Our study suggests an essential role of intracellular survival in macrophages in SA infections. These findings may have major implication for future treatment strategies

INTRODUCTION. Unicompartmental knee arthroplasty (UKA) is considered a highly successful procedure. However, complications and revisions may still occur, and some may be related to the operative technique. Computer assistance has been suggested to improve the accuracy of implantation of a UKA. The present study was designed to evaluate the long-term (more than 10 years) results of an UKA which was routinely implanted with help of a non-image based navigation system. MATERIAL AND METHODS. All patients operated on between 2004 and 2005 for implantation of a navigated UKA were included. Usual demographic and peri-operative items have been record. All patients were prospectively followed with clinical and radiological examination. All patients were contacted after the 10 year follow-up for repeat clinical and radiological examination (KSS, Oxford knee questionnaire and knee plain X-rays). Patients who did not return were interviewed by phone call. For patients lost of follow-up, family or general practitioner was contacted to obtain relevant information about prosthesis survival. Survival curve was plotted according to Kaplan-Meier. RESULTS. 57 UKAs were implanted during the study time-frame. Final follow-up (including death or revision) was obtained for 50 cases (88%). Clinical status after 10 years was obtained for 45 cases (80%). 4 prosthetic revisions were performed for mechanical reasons during the follow- up time (7%). The 10 year survival rate was 94%. No component was considered loose at the final radiographic evaluation. No polyethylene wear was detected at the final radiographic evaluation. DISCUSSION. This study confirms our initial hypothesis, namely quite satisfactory results of a navigated implanted UKA after more than 10 years. Navigation, whose precision is no longer to be demonstrated, probably contributed to the quality of the results. A more consistent anatomical reconstruction and ligamentous balance of the knee should lead to more consistent survival of the UKA. However, superiority of navigated UKA in comparison to conventional implanted UKA is difficult to prove because of the subtle differences expected in mostly underpowered studies. Longer term follow-up may be required

Purpose. Long-term clinical and radiographic results and survival rates were compared between closed-wedge high tibial osteotomy (HTOs) and fixed-bearing unicompartmental knee arthroplasty (UKA) in patients with similar demographics. Methods. Sixty HTOs and 50 UKAs completed between 1992 and 1998 were retrospectively reviewed. There were no significant differences in preoperative demographics. The mean follow-up period was 10.7 ±5.7 years for HTO and 12.0 ±7.1 years for UKA (n.s.). The Knee Society knee and function scores, WOMAC, and range of motion (ROM) were investigated. The mechanical axis and femorotibial angle were evaluated. Kaplan–Meier survival analysis was performed (failure: revision to TKA), and the failure modes were investigated. Results. Most of the clinical and radiographic results were not different at the last follow-up, except ROM; ROM was 135.3 ±12.3° in HTO and 126.8 ±13.3° in UKA (p=0.005). The 5-, 10-, 15-, and 20-year survival rates were 100%, 91.0%, 63.4%, and 48.3% for closed-wedge HTO, respectively, and 90.5%, 87.1%, 70.8%, and 66.4% for UKA (n.s.). The survival rate was higher than that for UKA until 12 years postoperatively but was higher in UKAs thereafter, following a remarkable decrease in HTO. The most common failure mode was degenerative osteoarthritic progression of medial compartment in HTO and femoral component loosening in UKA. Conclusions. Long-term survival did not differ significantly between closed-wedge HTO and fixed-bearing UKA in patients with similar preoperative demographics and knee conditions. The difference in postoperative ROM and failure mode should be considered when selecting a procedure

High grade sarcoma present a systemic metastatic progression in approximaly 50% of cases. The effectiveness of palliative chemotherapy as a treatment of systemic metastases is still controversed. The main objectif of this study is to assess disease progression and survival of patients diagnosed with metastatic soft tissue sarcomas treated with palliative chemotherapy, analyse chemotherapy treatment patterns and response to different lines of treatment. Retrospective chart review of 75 patients treated with palliative chemotherapy for metastatic soft tissue sarcomas between 2003 and 2013 at Maisonneuve-Rosemont Hospital. Data for control group of 40 patients with metastatic soft tissue sarcomas not treated with chemotherapy was collected retrospectively. Collected data include demographic data, overall survival, time free survival, type of chemotherapy treatment, surgical treatment and adverse reaction to palliative chemotherapy. Overall survival was analysed with Kaplan-Meier test. Categorial variable were compared with Log-Rank test. Seventy-five patients (37% female; mean age 50.4 years) received minimally one line of chemotherapy for their metastatic sarcomas. The regimens most commonly used in first-line were doxorubicin (48%) and doxorubicin combined with ifosfamide (21.3%). Favorable response was achieved by 38.7% in first-line and 27.9% in second-line therapy. Median overall survival with chemotherapy treatments was more than two times overall survival without treatments. Median overall survival was 19 months with chemotherapy treatments and 7 months without chemotherapy (p<0.0001). There was no statistically significant difference between survivals for treated and untreated patients with chemotherapy when analysed in term of the histological subtype, age and monotherapy versus combined treatment. Event-free survival was statistically longer during the first year for the group of patients treated with combined chemotherapy (p=0.0125). Results have shown a significantly improved overall survival in all histological groups, resulting in an OS of 19 vs 7 months for the chemotherpy and non chemotherapy group respectively. Nevertheless, patients with favorable response to chemotherapy have poor outcomes. Additional treatment options are needed

OBJECTIVES. The use of a mobile bearing has been suggested to decrease the rate of patellar complications after total knee arthroplasty (TKA). However, to resurface or retain the native patella remains debated. Few long-term results have been documented. The present retrospective study was designed to evaluate the long-term (more than 10 years) results of mobile bearing TKAs on a national scale, and to compare pain results and survivorship according to the status of the patella. The primary hypothesis of this study was that the 10 year survival rate of mobile bearing TKAs with patella resurfacing will be different from that of mobile bearing TKAs with native patella retaining. METHODS. All patients operated on between 2001 and 2004 in all participating centers for implantation of a TKA (whatever design used) were eligible for this study. Usual demographic and peri-operative items have been recorded. All patients were contacted after the 10 year follow-up for repeat clinical examination (Knee Society score (KSS), Oxford knee questionnaire). Patients who did not return were interviewed by phone call. For patients lost of follow-up, family or general practitioner was contacted to obtain relevant information about prosthesis survival. TKAs with resurfaced patella and TKAs with retained native patella were paired according to age, gender, body mass index and severity of the coronal deformation (with steps of 5°). Pain score, KSS and Oxford knee score were compared between two groups with a Student t-test at a 0.05 level of significance. Survival curve was plotted according to the actuarial technique, using the revision for mechanical reason as end-point. The influence of the patella status was assessed with a logrank test at a 0.05 level of significance. RESULTS. 1,604 TKAs were implanted during the study time-frame. 849 cases could be paired according to age, gender, BMI and severity of the pre-operative coronal deformation (2/1 ratio) into two groups: resurfaced patella (496 cases) and retained patella (243 cases). There was no difference in any baseline criteria between both groups. 150 patients deceased before the 10 year follow up (18%). Final follow-up was obtained for 489 cases (58%). 31 reoperations (prosthesis exchange or patellofemoral revision) were performed during the study time frame (4%), with 17 reoperations for mechanical reasons (3%). KSS and Oxford knee score were significantly higher for TKAs without patella resurfacing, there was a significant difference between the 13 year survival rates of TKAs with resurfaced patella (97%) and TKAs with retained native patella (93%). CONCLUSIONS. The primary hypothesis was confirmed: 10 year survival rate of mobile bearing TKAs with patella resurfacing was better than mobile bearing TKAs with native patella retaining. Patella resurfacing may lead to a better survival after mobile bearing TKA. However, the clinical results were better after patella resurfacing when the index TKA was not revised

Aim

To describe the impact of a failed DAIR in the further prognosis of the prosthesis after a PJI

Background. Unicompartmental knee arthroplasty provides a good alternative to total knee arthroplasty in patients with isolated medial compartment osteoarthritis. Reported ten-year survival for the Oxford medial unicompartmental knee arthroplasty is variable, ranging from 80.2% to 97.7% in the originator series. The aim of this study was to determine the survival and reasons for revision of the Oxford medial unicompartmental knee arthroplasty when performed at a specialist orthopaedic centre. Methods. Details of consecutive patients undergoing Oxford unicompartmental knee arthroplasty at our centre between January 2000 and December 2009 were collected prospectively. Failure of the implant was defined as conversion to total knee arthroplasty. Survival was determined using the Kaplan-Meier method. Results. There were 494 Oxford unicompartmental knee arthroplasties implanted in 425 patients for isolated medial compartment osteoarthritis. Mean age was 62.8 yrs (range 34.6-90.1 yrs) and 53.4% were female. During a mean follow-up time of 3.0 yrs (range 0.5-9.2 yrs), twenty-two knees (4.5%) were revised to a total knee arthroplasty. Reasons for revision were aseptic loosening of the femoral (n=8) or tibial component (n=2), undiagnosed pain (n=5), patellofemoral pain (n=2), infection (n=1), lateral meniscus tear (n=1), periprosthetic fracture (n=1), joint instability (n=1), and dislocation of meniscal bearing (n=1). Mean time to revision surgery from the primary procedure was 3.0 yrs. Eight-year survival for the cohort was 87.4%. The median pre-operative Oxford knee score was 62.5% which reduced to 27.7% at four years post-operatively. Conclusion. This study has demonstrated our revision rate for the Oxford unicompartmental knee replacement is comparable to independent series and national registry data. Post-operative function in patients not revised was good. The commonest reason for failure was aseptic component loosening which usually occurred within two to four years. Extended follow-up may therefore be beneficial in these patients so these cases are identified early and subsequently revised

Although there are several reports of excellent long-term survival after cemented total hip arthroplasty (THA), cemented acetabular components are prone to become loose when compared with femoral components. On the other hand, the survival of cementless acetabular components has been reported to be equal or better than cemented ones and the use of cementless acetabular components is increasing. However, most of the reports on survival after THA are for patients with primary hip osteoarthritis (OA) and there is no report of 20-year survival of cementless THA for patients with hip dysplasia. It is supposed to be more difficult to fix cementless acetabular components for OA secondary to hip dysplasia than primary OA. The purposes of this study were to review retrospectively the 20-year survival of cemented and cementless THA for hip dysplasia and to compare the effect of fixation methods on the long-term survival for patients with hip dysplasia. We retrospectively reviewed all patients with OA secondary to hip dysplasia treated with a cemented Bioceram hip system between 1981 and 1987, and a cementless cancellous metal Lübeck hip system between 1987 and 1991. We excluded patients aged more than 60 years, males, and Crowe 4 hips. The studied subjects were 70 hips of cemented THA (Group-C) and 57 hips of cementless THA (Group-UC). Both hip implants had a 28-mm alumina head on polyethylene articulation. The mean age at operation was 50.5 years (range, 36–60 years) in Group-C and 50.0 years (range, 29–60 years) in Group-UC. The mean BMI was 23.2 kg/m. 2. in Group-C (range, 17.3–29.3 kg/m. 2. ) and 22.9 kg/m. 2. in Group-UC (range, 18.8–28.0 kg/m. 2. ). There were no significant differences in age and BMI between the two groups. The average follow-up period was 18.0 years in Group-C and 18.4 years in Group-UC. In Group-C, revision was performed in 33 hips due to aseptic cup loosening (30 hips), stem loosening (one hip), and loosening of both components (two hips). In Group-UC, revision was performed in 10 hips due to stem fracture secondary to distal fixation (4 hips), cup loosening (three hips), polyethylene breakage (two hips), and extensive osteolysis around the stem (one hip). The survival at 20 years regarding any revision as the endpoint was 51% in Group-C and 84% in Group-UC. This difference was significant using Log-rank test (P=0.006). The cup survival at 20 years was 54% in Group-C and 92% in Group-UC. This difference was also significant (P = 0.0003). The stem survival at 20 years was 95% in Group-C and 92% in Group-UC. This difference was not significant (P = 0.4826). Cementless THA showed a higher survival rate at 20 years for hip dysplasia than cemented THA because of the excellent survival of the acetabular component without cement. We conclude that cementless THA with the cancellous metal Lübeck hip system led to better longevity at 20 years than cemented THA with the Bioceram for patients with OA secondary to hip dysplasia