Summary Statement

An autologous thrombin activated 3-fold PRP, mixed with a biphasic calcium phosphate at a 1mL:1cc ratio, is beneficial for early bone healing in older age sheep.

Aims

To evaluate mid-to long-term patient-reported outcome measures (PROMs) of endoprosthetic reconstruction after resection of malignant tumours arising around the knee, and to investigate the risk factors for unfavourable PROMs.

The primary aim was to assess survival of the opening wedge high tibial osteotomy (HTO) for medial compartment osteoarthritis. The secondary aim was to identify independent predictors of early (before 12 years) conversion to total knee arthroplasty (TKA).

During the 18-year period (1994–2011) 111 opening wedge HTO were performed at the study centre. Mean patient age was 45 years (range 18–68) and the majority were male (84%). Mean follow-up was 12 (range 6–21) years. Failure was defined as conversion to TKA. Kaplan-Meier, Cox regression and receiver operating curve (ROC) analyses were performed.

Forty (36%) HTO failed at a mean follow-up of 6.3 (range 1–15) years. The five-year survival rate was 84% (95% confidence interval (CI) 82.6–85.4), 10-year rate 65% (95% CI 63.5–66.5) and 15-year rate 55% (95% CI 53.3–56.7). Cox regression analysis identified older age (p<0.001) and female gender (hazard ratio (HR) 2.37, 95% CI 1.06–5.33, p=0.04) as independent predictors of failure. ROC analysis identified a threshold age of 47 years above which the risk of failure increased significantly (area under curve 0.72, 95% CI 0.62–0.81, p<0.001). Cox regression analysis, adjusting for covariates, identified a significantly greater (HR 2.49, 95% CI 1.26–4.91, p=0.01) risk of failure in patients aged 47 years old or more.

The risk of early conversion to TKA after an opening wedge HTO is significantly increased in female patients and those older than 47 years old. These risk factors should be considered pre-operatively and discussed with patients when planning surgical intervention for isolated medial compartment osteoarthritis.

Aims. The aims were to assess whether joint-specific outcome after total knee arthroplasty (TKA) was influenced by implant design over a 12-year follow-up period, and whether patient-related factors were associated with loss to follow-up and mortality risk. Methods. Long-term follow-up of a randomized controlled trial was undertaken. A total of 212 patients were allocated a Triathlon or a Kinemax TKA. Patients were assessed preoperatively, and one, three, eight, and 12 years postoperatively using the Oxford Knee Score (OKS). Reasons for patient lost to follow-up, mortality, and revision were recorded. Results. A total of 94 patients completed 12-year functional follow-up (62 females, mean age 66 years (43 to 82) at index surgery). There was a clinically significantly greater improvement in the OKS at one year (mean difference (MD) 3.0 (95% CI 0.4 to 5.7); p = 0.027) and three years (MD 4.7 (95% CI 1.9 to 7.5); p = 0.001) for the Triathlon group, but no differences were observed at eight (p = 0.331) or 12 years’ (p = 0.181) follow-up. When assessing the OKS in the patients surviving to 12 years, the Triathlon group had a clinically significantly greater improvement in the OKS (marginal mean 3.8 (95% CI 0.2 to 7.4); p = 0.040). Loss to functional follow-up (53%, n = 109/204) was independently associated with older age (p = 0.001). Patient mortality was the major reason (56.4%, n = 62/110) for loss to follow-up. Older age (p < 0.001) and worse preoperative OKS (p = 0.043) were independently associated with increased mortality risk. An age at time of surgery of ≥ 72 years was 75% sensitive and 74% specific for predicting mortality with an area under the curve of 78.1% (95% CI 70.9 to 85.3; p < 0.001). Conclusion. The Triathlon TKA was associated with clinically meaningful greater improvement in knee-specific outcome when compared to the Kinemax TKA. Loss to follow-up at 12 years was a limitation, and studies planning longer-term functional assessment could limit their cohort to patients aged under 72 years. Cite this article: Bone Jt Open 2024;5(10):911–919

Use of anticoagulants for thromboembolic prophylaxis is strongly supported by evidence. However, the use of these medications beyond the prophylactic period is poorly understood. We identified anticoagulant naïve patients that underwent hip or knee replacement between 2012 and 2019 from an arthroplasty registry and probabilistically linked 3,018 surgeries with nationwide pharmaceutical claims data. Rates of anticoagulation use were examined during the early (<= 60 days post-discharge), mid-term (61–180 days post-discharge) and long-term (181–360 days post-discharge) periods. Multivariable logistic regression analysis was performed to identify patient- and surgery-related factors associated with long-term anticoagulant use. Anticoagulants were supplied to 20% of arthroplasties within 60 days of discharge, 7% between 61–180 days, and 10% between 181–360 days. Older age, obesity, increased comorbidity burden, a longer length of stay, occurrence of a complication necessitating anticoagulation and dispensation of an anticoagulant within 60 days of discharge were all risk factors for long-term anticoagulant use. Given the risks associated with unnecessary use of these medications, certain patients who are prescribed anticoagulants beyond prophylactic period may benefit from specialist medication review in the months following surgery

Minimally displaced paediatric proximal humerus fractures (PHFs) can be reliably managed non-operatively, however there is considerable debate regarding the appropriate management of severely displaced PHFs, particularly in older children and adolescents with limited remodelling potential. The purpose of this study was to perform a systematic review to answer the questions: “What are the functional and quality-of-life outcomes of paediatric PHFs?” and “What factors have been associated with a poorer outcome?”. A review of Medline and EMBASE was performed on 4. th. July 2021 using search terms relevant to PHFs, surgery, non-operative management, paediatrics and outcomes. Studies including ≥10 paediatric patients with PHFs, which assessed clinical outcomes by use of an established outcome measure, were selected. The following clinical information was collected: participant characteristics, treatment, complications, and outcomes. Twelve articles were selected, including four prospective cohort studies and eight retrospective cohort studies. Favourable outcome scores were found for patients with minimally displaced fractures, and for children aged less than ten years, irrespective of treatment methodology or grade of fracture displacement. Older age at injury and higher grade of fracture displacement were reported as risk factors for a poorer patient-reported outcome score. An excellent functional outcome can be expected following non-operative management for minimally displaced paediatric PHFs. Prospective trials are required to establish a guideline for the management of severely displaced PHFs in children and adolescents according to fracture displacement and the degree of skeletal maturity

This study aimed to evaluate the month-to-month prevalence of antibiotic dispensation in the 12 months before and after total knee arthroplasty (TKA) and total hip arthroplasty (THA) and to identify factors associated with antibiotic dispensation in the month immediately following the surgical procedure. In total, 4,115 THAs and TKAs performed between April 2013 and June 2019 from a state-wide arthroplasty referral centre were analysed. A cross-sectional study used data from an institutional arthroplasty registry, which was linked probabilistically to administrative dispensing data from the Australian Pharmaceutical Benefits Scheme. Multivariable logistic regression was carried out to identify patient and surgical risk factors for oral antibiotic dispensation. Oral antibiotics were dispensed in 18.3% of patients following primary TKA and 12.0% of patients following THA in the 30 days following discharge. During the year after discharge, 66.7% of TKA patients and 58.2% of THA patients were dispensed an antibiotic at some point. Patients with poor preoperative health status were more likely to have antibiotics dispensed in the month following THA or TKA. Older age, undergoing TKA rather than THA, obesity, inflammatory arthritis, and experiencing an in-hospital wound-related or other infectious complications were associated with increased antibiotic dispensation in the 30 days following discharge. A high rate of antibiotic dispensation in the 30 days following THA and TKA has been observed. Although resource constraints may limit routine wound review for all patients by a surgeon, a select cohort may benefit from timely specialist review postoperatively. Several risk factors identified in this study may aid in identifying appropriate candidates for such changes to follow-up care

Routine post-operative bloods following all elective arthroplasty may be unnecessary. This retrospective cohort study aims to define the proportion of post-operative tests altering clinical management. Clinical coding identified all elective hip or knee joint replacement under Hawkes Bay District Health Board contract between September 2019-December 2020 (N=373). Uni-compartmental and bilateral replacements, procedures performed for cancer, and those with insufficient data were excluded. Demographics, perioperative technique, and medical complication data was collected. Pre- and post-operative blood tests were assessed. Outcome measures included clinical intervention for abnormal post-operative sodium (Na), creatinine (Cr), haemoglobin (Hb), or potassium (K) levels. A cost-benefit analysis assessed unnecessary testing. 350 patients were Included. Median age was 71 (range 34-92), with 46.9% male. Only 26 abnormal post-operative results required intervention (7.1%). 11 interventions were for low Na, 4 for low K, and 4 for elevated Cr. Only 7 patients were transfused blood products. Older age (p=0.009) and higher ASA (p=0.02) were associated with intervention of any kind. Abnormal preoperative results significantly predicted intervention for Na (p<0.05) and Cr (p<0.05). All patients requiring treatment for K used diuretic medication. Preoperative Hb level was not associated with need for transfusion. Overall, there were 1027 unnecessary investigations resulting in $18,307 excess expenditure. Our study identified that the majority of elective arthroplasty patients do not require routine postoperative blood testing. We recommend investigations for patients with preoperative electrolyte abnormality, those taking diuretics, and patients with significant blood loss noted intra-operatively. In future, a larger, randomised controlled trial would be useful to confirm these factors

High energy pelvic injury poses a challenging setting for the treating surgeon. Often multiple injuries are associated, which makes the measurement of short- and long-term functional outcomes a difficult task. The purpose of this study was to determine the incidence of pelvic dysfunction and late impacts of high energy pelvic ring fractures on pelvic floor function in women, with respect to urinary, sexual and musculoskeletal function. This was compared to a similar cohort of women with lower limb fractures without pelvis involvement. The data in our study was prospectively gathered between 2010 and 2013 on 229 adult females who sustained injury between 1998 and 2012. Besides demographic and operative variables, the scores of three validated health assessment tools were tabulated: King's Health Questionnaire (KHQ), Female Sexual Function Index (FSFI) and the Short Musculoskeletal Functional Assessment (SMFA). A multivariate regression analysis was done to compare groups. The incidence of sexual dysfunction was 80.8% in the pelvis and 59.4% in the lower extremity group. A Wilcoxon rank sum test showed a significant difference in KHQ-score (p<0.01) with the pelvis group being worse. When adjusting for age, follow-up and Injury Severity Score this difference was not significant (p=0.28), as was for FSFI and SMFA score. The mean FSFI scores of both groups met the criteria for female sexual dysfunction (<26). Patients with a Tile C fracture have better FSFI scores (16.98) compared to Tile B fractures (10.12; p=0.02). Logistic regression predicting FSFI larger than 26.5 showed that older age and pelvic fractures have a higher likelihood having a form of sexual dysfunction. Sexual dysfunction after lower extremity trauma is found in patients regardless of pelvic ring involvement. Urinary function is more impaired after pelvic injuries, but more data is needed to confirm this. Older age and pelvic fracture are predictors for sexual dysfunction in women. This study is important as it could help counsel patients on the likelihood of sexual dysfunction, something that is probably under-reported and recognized during our patient follow up

Correct femoral tunnel position in anterior cruciate ligament reconstruction (ACLR) is critical in obtaining good clinical outcomes. We aimed to delineate whether any difference exists between the anteromedial (AM) and trans-tibial (TT) portal femoral tunnel placement techniques on the primary outcome of ACLR graft rupture. Adult patients (>18year old) who underwent primary ACLR between January 2011 – January 2018 were identified and divided based on portal technique (AM v TT). The primary outcome measure was graft rupture. Univariate analysis was used to delineate association between independent variables and outcome. Binary logistic regression was utilised to delineate odds ratios of significant variables. 473 patients were analysed. Median age at surgery was 27 years old (range 18–70). A total of 152/473, (32.1%) patients were AM group compared to 321/473 (67.9%) TT. Twenty-five patients (25/473, 5.3%) sustained graft rupture. Median time to graft rupture was 12 months (IQR 9). A higher odds for graft rupture was associated with the AM group, which trended towards significance (OR 2.03; 95% CI 0.90 – 4.56, p=0.081). Older age at time of surgery was associated with a lower odds of rupture (OR 0.92, 95% CI 0.86 – 0.98, p=0.014). There is no statistically significant difference in ACLR graft rupture rates when comparing anteromedial and trans-tibial portal technique for femoral tunnel placement. There was a trend towards higher rupture rates in the anteromedial portal group

True scaphoid fractures of the wrist are difficult to diagnose in children. In 5–40% of cases, a scaphoid fracture may not be detectable on initial X-ray, some fractures may take up to six weeks to become evident. Since missing a scaphoid fracture may have serious implications, many children with a suspected or “clinical” scaphoid fracture, but normal radiographs, may be over-treated. The purpose of this study was to identify predictors of true scaphoid fractures in children. A retrospective cohort study was performed using electronic medical records for all patients over a two-year period presenting to a tertiary paediatric hospital with hand or wrist injury. Charts were identified by ICD-10 diagnostic codes and reviewed for pre-specified inclusion and exclusion criteria. Patients with either a clinical or true scaphoid fracture were included. When a scaphoid fracture was suspected, but imaging was negative for fracture, the diagnosis of a clinical scaphoid fracture was made. True scaphoid fractures were diagnosed when a fracture was evident on any modality of medical imaging (X-ray, CT, MRI) at any time post-injury. Over the two-year study period, 148 patients (60 scaphoid fractures, 88 non-fractures) met inclusion and exclusion criteria for review. Mean (±SD) age was 13±2 years and 52% were male. The left wrist was injured in 61% of cases. Of the 60 true scaphoid fractures, mean age was 14±2 years, and 69% were male. Fracture location was primarily at the waist (48%) or distal pole (45%) of the scaphoid. Sports were the prevailing mechanism of injury. Six (11%) underwent surgery. Multivariate logistic regression demonstrated that older age, male gender, and right-sided injury were predictors of scaphoid fracture with odds ratios of 1.3 (95% CI: 1.1–1.6, p=0.005), 2.8 (95% CI: 1.3–6, p=0.007), and 2.4 (95% CI: 1.1–5.2, p=0.025). Older age, male gender, and right-sided injury may be predictors of scaphoid fractures in children. Further evidence to support this may enable the formulation of clinical guidelines or rules to reduce the overtreatment of children presenting with a clinical scaphoid fracture

Post-operative infection is a serious complication of spine surgery and can contribute to the strain on the healthcare system's resources. The purpose of this study is to determine what factors affect the risk of developing postoperative infection. We hypothesize that female gender, smoking, diabetes, having thoracolumbar procedures, having a neurological deficit, increased age, body mass index (BMI), American Society of Anaesthesiologists (ASA) score, blood loss, number of operative levels, operative time and undergoing non-elective surgery will increase the patients' risk of developing a post-operative infection. A retrospective review of prospectively collected data within the Canadian Spine Outcome and Research Network (CSORN) was conducted. Data was analyzed using IBM-SPSS. Multivariable logistical regression analysis was conducted (odds ratios) to determine any association between the outcome and independent factors. Significance level was p < 0.05. There were 7747 patients identified from the registry that had completed at least 12 weeks of follow up. There were 199 infections recorded representing a 2.6% risk of infection. There were no association found between the risk of developing a post operative infection and gender, smoking, diabetes, having thoracolumbar procedures, having a neurological deficit, ASA score, blood loss, number of operative levels and undergoing non-elective surgery. The following were associated with an increased risk of developing a post operative infection: Older age (adjusted OR=1.021, 95% CI=1.005–1.038, p < 0 .05), having an elevated BMI (adjusted OR=1.042, 95% CI=1.013–1.072, p < 0 .005), longer operative time (adjusted OR=1.002, 95% CI=1.001–1.004, p < 0 .001). There is a 2.6% overall rate of post-operative spine infection across 20 Canadian centres. The factors that were associated with an increased risk of developing a post operative-infection were older age, increased BMI and longer operative time. This study establishes a benchmark against which the effectiveness of future interventions to reduce infection can be compared

Increased emphasis has been placed on hospital length of stay and discharge planning after total joint arthroplasty. The purpose of this study was to identify patient characteristics and assistance of surgical innovation could reduce length of stay of an inpatient after TJA. Method: We analysed demographic and Clinical data 92 consecutive patients who underwent primary TKR with computer assisted surgery [n=46] and compare with another group operated with manual technique[n=46]. Result: Average length of stay: 8.87days (+/− 5.16 SD) in the navigation group and 7.59days (+/− 3.82 SD) in the manual group. Older age, higher American Society of Anesthesiologists class, social circumstances, and female sex were all associated with a higher likelihood of discharge to an ECF. Conclusion: No Significant differences in length of stay patterns were found in this cohort with respect to discharge disposition at home after knee joint replacement. We believe to reduce length of stay while maintaining quality of care, early discharge home with integrated community services or home care nursing and physiotherapy should be more important than surgical innovation in the NHS in U.K

Dislocation remains a common complication following total hip arthroplasty, second only to aseptic loosening as a cause of revision. Factors thought to play a role in dislocation include cup and stem alignment, soft tissue tension, surgical approach, patient factors, and design features of the prosthesis, including femoral head size. We analysed all consecutive total hip replacements at one institution over a 17 year period. Criteria for study inclusion were hips replaced due to primary osteoarthritis with no previous surgery, femoral head sizes of 28mm and 32mm only, and at least one year from date of surgery. 3682 hips fulfilled these criteria. All procedures were carried out using a posterolateral approach with enhanced posterior repair, and a standard method of intraoperative soft tissue balance assessment. The rate of dislocation was 1.6%. 32mm femoral head size was associated with a statistically significant lower rate of dislocation. However, after controlling for different follow-up times between 28mm and 32mm heads, this difference was no longer observed. Older age at time of surgery and decreased cup anteversion were shown to be significantly associated with an increased risk of dislocation. Ceramic on ceramic bearing surface was significantly associated with a decreased risk of dislocation, after controlling for age, bearing wear and time from surgery. Cup inclination, gender, BMI, and preoperative hip score were not related to dislocation risk. Our dislocation rate may reflect current dislocation rates of surgeons using the posterolateral approach with posterior capsule and external rotator repair. The risk factors identified and excluded in this study are likely to be relevant to all surgeons who utilise this approach in total hip arthroplasty

Dislocation remains a common complication following total hip arthroplasty, second only to aseptic loosening as a cause of revision. Factors thought to play a role in dislocation include cup and stem alignment, soft tissue tension, surgical approach, patient factors, and design features of the prosthesis, including femoral head size. We analysed all consecutive total hip replacements at one institution over a 17 year period. Criteria for study inclusion were hips replaced due to primary osteoarthritis with no previous surgery, femoral head sizes of 28mm and 32mm only, and at least one year from date of surgery. 3682 hips fulfilled these criteria. All procedures were carried out using a posterolateral approach with enhanced posterior repair, and a standard method of intraoperative soft tissue balance assessment. The rate of dislocation was 1.6%. 32mm femoral head size was associated with a statistically significant lower rate of dislocation. However, after controlling for different follow-up times between 28mm and 32mm heads, this difference was no longer observed. Older age at time of surgery and decreased cup anteversion were shown to be significantly associated with an increased risk of dislocation. Ceramic on ceramic bearing surface was significantly associated with a decreased risk of dislocation, after controlling for age, bearing wear and time from surgery. Cup inclination, gender, BMI, and preoperative hip score were not related to dislocation risk. Our dislocation rate may reflect current dislocation rates of surgeons using the posterolateral approach with posterior capsule and external rotator repair. The risk factors identified and excluded in this study are likely to be relevant to all surgeons who utilise this approach in total hip arthroplasty

Introduction and Aims: To define the economic and health costs of waiting for THJR surgery. Method: A prospective cohort of 122 patients requiring primary total hip arthroplasty (HA) was recruited from four hospitals. Health-related quality of life (HRQL) using self-completed WOMAC questionnaires was assessed monthly from enrolment pre-operatively to six months post-surgery. Monthly cost diaries were used to record medical, personal and other costs. Data was analysed using PC-SAS to test the strength of associations between costs and waiting times, and changes in HRQL pre- and post-surgery. Results: The mean waiting time was 5.2 months, and the mean cost of waiting for surgery was NZ$1376 per person per month, with medical, personal, and social costs contributing NZ$404, NZ$399, NZ$573, respectively. Waiting for more than six months was associated with an increased cost of NZ$730 per patient per month for a total cost of NZ$2177 per patient per month. Age was correlated with greater loss of income and higher medical costs. An incremental improvement over time in WOMAC scores post-operatively was identified. Older age, community services card use and a greater number of months waiting were negatively correlated with post-surgical improvement. Conclusion: Longer waits for HA incur greater economic costs and impact on patient recovery. This shows that shorter waiting time for HA significantly reduces costs to individuals and society and improves health outcomes

Objective: to investigate the long-term clinical and radiological outcome of talar avascular necrosis after treatment by a patellar-tendon bearing brace (PTB), and if parameters predictive for a positive or negative outcome could be identified. Patients and methods: 21 patients were reviewed retrospectively, 10 had a non-traumatic origin and 11 a traumatic one (groups comparable to gender and age). Mean follow-up was 5,5 and 6,3 years, respectively; mean use of the PTB was 17,2 and 14,8 months. Clinical outcome was assessed by the Mazur scale and the Kitaoka score for function, and a VAS for pain and subjective satisfaction; radiological outcome by the Ficat & Arlet classification and by the Kellgren scale. Clinical parameters were analysed for their positive or negative predictive value on outcome. Results: A very early pain control was achieved in both groups (2.1 versus 1.9 weeks). On both the Mazur scale and the Kitaoka score the non-traumatic group scored lower as the posttraumatic group (66,3 versus 77,6 and 76.1 versus 78.1). Both VAS were similar in both groups: 3,1 and 3,6 for pain and 6,8 and 7,1 for satisfaction. The need for analgesic medication was slightly higher in the non-traumatic group: 4 versus 3 patients. Radiologically both groups showed a similar outcome with both evaluation systems. Older age, delay in treatment, corticosteroids, alcohol, hyperlipidaemia and female gender were identified as negative predictive parameters. Conclusions: A PTB is an efficient treatment for talar avascular necrosis of both non-traumatic and traumatic origin. Clinical outcome is better in the posttraumatic group, although radiological outcome is comparable. Only negative predictive parameters could be identified

The purpose was to define the economic and health costs of waiting for total hip joint replacement surgery. A prospective cohort of 122 patients requiring primary hip arthroplasty (HA) was recruited from four hospitals in the lower North Island. Health related quality of life (HRQL), using self-completed WOMAC questionnaires, was assessed monthly from enrolment pre-operatively to six months post surgery. Monthly cost diaries were used to record medical, personal and other costs. Data was analysed using PC-SAS to test the strength of associations between costs and waiting times, and changes in HRQL pre- and post-surgery. The mean waiting time was 5.2 months and mean cost of waiting for surgery was $1,376 per person per month (pp pm) with medical, personal and social costs contributing $404, $399, and $573, respectively. Waiting more than 6 months was associated with an increased cost of $730 pp pm for a total cost of $2177 pp pm (p< 0.003). Age was correlated with greater loss of income (< 65 years) (p=0.001) and higher medical costs (< 65 years) (p=0.08). An incremental improvement over time in WOMAC scores post-operatively was identified (p=0.0001). Older age (p=0.01), community services card use (p=0.003) and a greater number of months waiting (p=0.1) were negatively correlated with post-surgical improvement after adjusting for other variables. Longer waits for HA incur greater economic costs and impact on patient recovery. This lends weight to the view that a shorter waiting time for HA significantly reduces costs to individuals and society and improves health outcomes

Purpose. The main predictors in the literature of local control for patients operated on for a soft tissue sarcoma are age, local presentation status, depth, grade, size, surgical margins and radiation. However, due to the competing effect of death (patients who die are withdrawn from the risk of local recurrence), the influence of these predictors on the cumulative probabilities may have been misinterpreted so far. The objective of the study was to interpret the influence of known predictors of local recurrence in a competing risks setting. Method. This single center study included 1519 patients operated on for a localized soft tissue sarcoma of the extremity or trunk. Cox models were used to estimate the cause specific hazard of known predictors on local recurrence. Cumulative incidences were estimated in a competing risks scenario. Results. Overall the cumulative probabilities of local recurrence at 2, 5, and 10 years were 5.4% (4.3%–6.7%), 8.2% (6.8%–9.8%), and 11.7% (9.8%–14.3%). The cumulative probabilities of metastasis at 2, 5, and 10 years were 23.3% (21.1%–25.5%), 28.7% (26.2%–31.1%), and 33.7% (30.8%–36.7%). Older age, locally recurrent, high grade and deep tumors, absence of radiation and positive surgical margins were significantly associated with an increased risk of local recurrence. However, when considering competing risks, the cumulative probabilities of local recurrence were significantly different only with presentation status (P < 0.0001), surgical margins (P < 0.0001) and use of adjuvant radiation (P = 0.04). At 10 years, the cumulative probability of local recurrence was 10.6% and 22.6% for patients presenting with a primary or locally recurrent tumor, 9.3% and 23.3% for patients with negative or positive surgical margins, and 9.8% and 16.8% for patients receiving or not receiving radiation respectively. There was no difference in the cumulative probabilities of local recurrence with regard to tumor depth (P = 0.29), size (P = 0.78) or grade (P = 0.29). Patient survival at 2, 5, and 10 years was 85.5% (95% CI: 83.7%–87.4%), 74.6% (95% CI: 72.1%–77.1%), and 64.3% (95% CI: 61%–67.7%). Conclusion. The effect of variables on the cumulative probability of local recurrence should be interpreted in a competing risks setting. Grade and depth are not associated with an increased cumulative probability of local recurrence

Introduction. Meaningful clinical improvement as demonstrated through patient-reported outcome measures (PROMs) are increasingly used to evaluate success of total hip arthroplasty (THA) procedures. This patient perspective can provide a full picture when used with clinical data to best evaluate surgical outcomes. Methods. All primary THA procedures reported to the American Joint Replacement Registry from 2012–2018 with linked pre-operative and 1-year post-operative functional or anatomical PROMs were included. The achievement of minimal clinically-important difference (MCID) was calculated using the distribution method. Logistic regression models with covariate adjustment for patient demographics, American Society of Anesthesiologists (ASA) score, and body mass index (BMI) were constructed to identify associations with PROMs. Results were analyzed based on hospital size (small, medium and large) and teaching type (non-teaching, minor and major) based on the American Hospital Association Survey (2015). Results. There were 3,952 THA with pre-operative and 1-year post-operative PROMs. The five types of PROMs collected include: HOOS (n=731), HOOS Jr. (n=295), PROMIS-10 (n=1,074), SF-36 (n=976), VR-12 (1,262). The average age was 66.3±10.5 years, and the majority were female (54.7%). 53.1% of THA patients achieved MCID. Age and gender were statistically significant, while ASA score and BMI classification were not. As age increased by 1 year, the odds of achieving MCID increased 0.8% (OR 0.992, 95%CI 0.984, 0.999) and a minor versus major teaching hospital was 20.8% less likely to achieve MCID (p<0.04). While small hospital sizes had significantly fewer linked PROMs (6.5% of all linked PROMs), only 44.5% achieved MCID compared to medium (52.3%) and large (54.5%) hospitals (p<0.02). Conclusion. Older patient age, major teaching hospitals, and large hospitals achieved higher levels of MCID after THA. Identifying patients that are less likely to achieve MCID can aid physicians by determining patients at risk for poor outcomes, then guiding patient expectations and providing patient-centered care. For any tables or figures, please contact the authors directly