Time to full weight-bearing with the use of a calcium sulfate-calcium phosphate bone substitute as a bone void filler following extended curettage in the treatment of primary benign bone tumours.

PURPOSE: The primary objective of this study was to determine time to full weight-bearing after the use of a calcium-sulfate-calcium phosphate bone substitute (CaSO4/CaPO4) as a bone void filler in the treatment of primary benign bone tumours following intralesional curettage. The secondary objectives were to determine surgical complications and recurrence rates. METHODS: Retrospective review of patients identified from a surgeon-specific orthopaedic oncology database, who underwent curettage of benign bone tumours and subsequent bone void filling with CaSO4/CaPO4. RESULTS: A total of 39 patients (20 males, 19 females) met inclusion criteria with an average age of 31 years (range: 13 to 62 years), a median follow-up of 3.7 years, and a maximum follow-up of 11 years. The most common tumour diagnosis was giant cell tumour of bone (GCT) (n = 19), and the most common location was the proximal tibia (n = 9). The mean volume of tumour excised was 74.1 cm3 including extraosseous bone expansion due to tumour growth, with a mean of volume of 21.4 mL of CaSO4/CaPO4 used to fill the intraosseous cavitary defects to restore normal bone anatomy. None of the lesions required additional internal fixation. The primary outcome measure, average time to full weight-bearing/full range of motion, was 11 weeks and 6 weeks for upper and lower extremity lesions, respectively. Secondary outcomes included tumour recurrence requiring reoperation in five patients and infection requiring reoperation in two patients. CONCLUSION: This study demonstrates that CaSO4/CaPO4 is a viable option as a bone void filler in the reconstruction of cavitary defects following removal of primary benign bone tumours. CaSO4/CaPO4 provides sufficient bone regeneration early in the post-operative period to allow progression to full weight-bearing within weeks without the need for internal fixation. There were no graft-specific complications noted.

Risk Factors for All-Cause Early Reoperation Following Tumor Resection and Endoprosthetic Reconstruction: A Secondary Analysis from the PARITY Trial.

BACKGROUND: Oncologic resection and endoprosthetic reconstruction of lower-extremity musculoskeletal tumors are complex procedures fraught with multiple modes of failure. A robust assessment of factors contributing to early reoperation in this population has not been performed in a large prospective cohort. The aim of the present study was to assess risk factors for early reoperation in patients who underwent tumor excision and endoprosthetic reconstruction, with use of data from the Prophylactic Antibiotic Regimens in Tumor Surgery (PARITY) trial. METHODS: Baseline characteristics were assessed, including age, sex, tumor type, tumor location, presence of a soft-tissue mass, diabetes, smoking status, chemotherapy use, and neutropenia. Operative factors were recorded, including operative time, topical antibiotics, silver-coated prosthetics, endoprosthetic fixation, extra-articular resection, length of bone resected, margins, tranexamic acid, postoperative antibiotics, negative-pressure wound therapy, and length of stay. Univariate analysis was utilized to explore the differences between patients who did and did not undergo reoperation within 1 year postoperatively, and a multivariate Cox proportional hazards regression model was utilized to explore the predictors of reoperation within 1 year. RESULTS: A total of 155 (25.7%) of 604 patients underwent ≥1 reoperation. In univariate analysis, tumor type (p < 0.001), presence of a soft-tissue mass (p = 0.045), operative time (p < 0.001), use of negative-pressure wound therapy (p = 0.010), and hospital length of stay (p < 0.001) were all significantly associated with reoperation. On multivariate assessment, tumor type (benign aggressive bone tumor versus primary bone malignancy; hazard ratio [HR], 0.15; 95% confidence interval [CI], 0.04 to 0.63; p = 0.01), operative time (HR per hour, 1.15; 95% CI, 1.10 to 1.23; p < 0.001), and use of negative-pressure wound therapy (HR, 1.93; 95% CI, 1.30 to 2.90; p = 0.002) remained significant predictors of reoperation within 1 year. CONCLUSIONS: Independent variables associated with reoperation within 1 year in patients who underwent tumor resection and endoprosthetic reconstruction included tumor type (benign aggressive bone tumor versus primary bone malignancy), operative time, and use of negative-pressure wound therapy. These results will help to inform patients and surgeons regarding the risk of reoperation by diagnosis and reinforce operative time as a factor influencing reoperation. These results also support further investigation into the use of negative-pressure wound therapy at the time of surgery in this patient population. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Opioid Use in Surgical Management in Musculoskeletal Oncology.

BACKGROUND: Opioid prescribing in the context of orthopaedic surgery has been recognized as having a critical role in the ongoing opioid epidemic. Given the negative consequences of chronic opioid use, great efforts have been made to reduce both preoperative and postoperative opioid prescribing and consumption in orthopaedic surgery. Musculoskeletal oncology patients represent a unique subset of patients, and there is a paucity of data evaluating perioperative opioid consumption and the risk for chronic use. The objective of the present study was to describe opioid consumption patterns and evaluate predictors of chronic opioid use in musculoskeletal oncology patients undergoing limb-salvage surgery and endoprosthetic reconstruction. METHODS: The present study was a secondary analysis of the recently completed PARITY (Prophylactic Antibiotic Regimens in Tumor Surgery) trial and included musculoskeletal oncology patients undergoing lower-extremity endoprosthetic reconstruction. The primary outcome was the incidence of opioid consumption over the study period. A multivariate binomial logistic regression model was created to explore predictors of chronic opioid consumption at 1 year postoperatively. RESULTS: Overall, 193 (33.6%) of 575 patients were consuming opioids preoperatively. Postoperatively, the number of patients consuming opioids was 82 (16.7%) of 492 at 3 months, 37 (8%) of 460 patients at 6 months, and 28 (6.6%) of 425 patients at 1 year. Of patients consuming opioids preoperatively, 12 (10.2%) of 118 had continued to consume opioids at 1 year postoperatively. The adjusted regression model found that only surgery for metastatic bone disease was predictive of chronic opioid use (odds ratio, 4.90; 95% confidence interval, 1.54 to 15.40; p = 0.007). Preoperative opioid consumption, older age, sex, longer surgical times, reoperation rates, and country of origin were not predictive of chronic use. CONCLUSIONS: Despite a high prevalence of preoperative opioid use, an invasive surgical procedure, and a high rate of reoperation, few patients had continued to consume opioids at 1 year postoperatively. The presence of metastases was associated with chronic opioid use. These results are a substantial departure from the existing orthopaedic literature evaluating other patient populations, and they suggest that specific prescribing guidelines are warranted for musculoskeletal oncology patients. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

The Impact of Implant Fixation Type on Reoperation Rates Following Endoprosthetic Reconstruction Surgery.

BACKGROUND: Prospective evidence supporting the use of cemented or uncemented implants in endoprosthetic reconstruction is lacking. The present study aimed to determine the effect of cemented fixation compared with uncemented fixation on the rate of all-cause reoperation at 1 year postoperatively. METHODS: This is a secondary analysis of the Prophylactic Antibiotic Regimens In Tumor Surgery (PARITY) trial. A total of 503 patients who underwent surgical excision and endoprosthetic reconstruction of a lower-extremity bone tumor were included in this analysis. A multivariate Cox proportional hazards model was utilized to assess the independent relationship between fixation group and implant survivorship, with all-cause reoperation as the end point. RESULTS: There were 388 cemented implants and 115 uncemented implants. Participants had a mean age of 42.7 years (standard deviation, 22.0 years), and 59% were male. Overall, 131 reoperations were identified over the 1-year follow-up period. There were no significant differences found in all-cause reoperation (hazard ratio [HR], 1.05; 95% confidence interval [CI], 0.70 to 1.57; p = 0.761), septic reoperation, or aseptic reoperation between cemented and uncemented fixation at 1 year postoperatively. The Cox regression analysis demonstrated that total operative time (HR per hour, 1.10; 95% CI, 1.02 to 1.20; p = 0.019) was an independent predictor of reoperation. The risk of reoperation was lower in patients with benign aggressive disease (HR, 0.11; 95% CI, 0.02 to 0.80; p = 0.029) or metastatic bone disease (HR, 0.30; 95% CI, 0.11 to 0.85; p = 0.023). Patients who underwent cemented fixation showed clinically meaningful functional improvement at 1 year postoperatively. CONCLUSIONS: Cemented compared with uncemented fixation has no effect on 1-year all-cause reoperation rates in endoprosthetic reconstruction surgery. Further research is required to investigate the long-term survival of cemented versus uncemented implants. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Pediatric and Adult Patients Have Similar Functional Improvement After Endoprosthetic Reconstruction of Lower-Extremity Tumors.

BACKGROUND: Although the treatment of lower-extremity bone tumors is similar between adult and pediatric patients, differences in outcomes are unknown. Outcomes for lower-extremity oncologic reconstruction have been challenging to study because of the low incidence and heterogeneity in disease and patient characteristics. The PARITY (Prophylactic Antibiotic Regimens in Tumor Surgery) trial is the largest prospective data set assembled to date for patients with lower-extremity bone tumors and presents an opportunity to investigate differences in outcomes between these groups. METHODS: Patient details were acquired from the prospectively collected PARITY trial database. The 1993 Musculoskeletal Tumor Society (MSTS-93) and Toronto Extremity Salvage Score (TESS) questionnaires were administered preoperatively and at 3, 6, and 12 months postoperatively. Continuous outcomes were compared between groups with use of the Student t test, and dichotomous outcomes were compared with use of the Pearson chi-square test. RESULTS: A total of 150 pediatric and 447 adult patients were included. Pediatric patients were more likely than adult patients to have a primary bone tumor (146 of 150 compared with 287 of 447, respectively; p < 0.001) and to have received adjuvant chemotherapy (140 of 149 compared with 195 of 441, respectively; p < 0.001). Reoperation rates were not significantly different between age groups (45 of 105 pediatric patients compared with 106 of 341 adult patients; p ≤ 0.13). Pediatric patients had higher mean MSTS-93 scores (64.7 compared with 53.8 among adult patients; p < 0.001) and TESS (73.4 compared with 60.4 among adult patients; p < 0.001) at baseline, which continued to 1 year postoperatively (mean MSTS-93 score, 82.0 compared with 76.8 among adult patients; p = 0.02; mean TESS, 87.7 compared with 78.6 among adult patients; p < 0.001). Despite the differences in outcomes between cohorts, pediatric and adult patients demonstrated similar improvement in MSTS-93 scores (mean difference, 17.4 and 20.0, respectively; p = 0.48) and TESS (mean difference, 14.1 and 14.7, respectively; p = 0.83) from baseline to 1 year postoperatively. CONCLUSIONS: Pediatric patients had significantly better functional outcomes than adult patients at nearly all of the included postoperative time points; however, pediatric and adult patients showed similar mean improvement in these outcomes at 1 year postoperatively. These findings may be utilized to help guide the postoperative expectations of patients undergoing oncologic reconstruction. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Patient and Surgical Risk Factors for Surgical Site Infection in Lower-Extremity Oncological Endoprosthetic Reconstruction: A Secondary Analysis of the PARITY Trial Data.

BACKGROUND: The specific risk factors for surgical site infection (SSI) in orthopaedic oncology patients undergoing endoprosthetic reconstruction have not previously been evaluated in a large prospective cohort. In the current study, we aimed to define patient- and procedure-specific risk factors for SSI in patients who underwent surgical excision and endoprosthetic reconstruction for lower-extremity bone or soft-tissue tumors using the prospectively collected data of the Prophylactic Antibiotic Regimens in Tumor Surgery (PARITY) trial. METHODS: PARITY was a multicenter, blinded, randomized controlled trial with a parallel 2-arm design that aimed to determine the effect of a long duration (5 days) versus short duration (24 hours) of postoperative prophylactic antibiotics on the rate of SSI in patients undergoing surgical excision and endoprosthetic reconstruction of the femur or tibia. In this secondary analysis of the PARITY data, a multivariate Cox proportional hazards regression model was constructed to explore predictors of SSI within 1 year postoperatively. RESULTS: A total of 96 (15.9%) of the 604 patients experienced an SSI. Of the 23 variables analyzed in the univariate analysis, 4 variables achieved significance: preoperative diagnosis, operative time, volume of muscle excised, and hospital length of stay (LOS). However, only hospital LOS was found to be independently predictive of SSI in the multivariate regression analysis (hazard ratio per day = 1.03; 95% confidence interval = 1.01 to 1.05; p < 0.001). An omnibus test of model coefficients demonstrated that the model showed significant improvement over the null model (χ2 = 78.04; p < 0.001). No multicollinearity was found. CONCLUSIONS: This secondary analysis of the PARITY study data found that the only independent risk factor for SSI on multivariate analysis was hospital LOS. It may therefore be reasonable for clinicians to consider streamlined discharge plans for orthopaedic oncology patients to potentially reduce the risk of SSI. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Operative Treatment and Outcomes of Pediatric Patients with an Extremity Bone Tumor: A Secondary Analysis of the PARITY Trial Data.

BACKGROUND: Osteosarcoma and Ewing sarcoma are the 2 most common primary bone sarcomas, occurring predominantly in pediatric patients, with the incidence of osteosarcoma correlating with periods of peak bone-growth velocity. Although survival outcomes have plateaued over the past several decades, ongoing treatment advances have improved function, decreased infection rates, and improved other clinical outcomes in patients with bone tumors. Recently, the Prophylactic Antibiotic Regimens in Tumor Surgery (PARITY) trial addressed the serious problem of surgical site infection (SSI) and the lack of consensus regarding the appropriate prophylactic postoperative antibiotic regimen. The objective of the present secondary analysis of the PARITY trial was to characterize the modern treatment and surgical and oncologic outcomes of pediatric patients with bone tumors at 1 year postoperatively. METHODS: The PARITY trial included patients ≥12 years old with a bone tumor or soft-tissue sarcoma that was invading the femur or tibia, necessitating osseous resection and endoprosthetic reconstruction. This pediatric subanalysis of the PARITY trial data included all PARITY patients ≤18 years old. As in the main PARITY study, patients were randomized to either a 5-day or 1-day course of postoperative antibiotic prophylaxis. The primary outcome measure was the development of an SSI within 1 year, and secondary outcomes included antibiotic-related adverse events, unplanned additional operations, local recurrence, metastasis, and death. RESULTS: A total of 151 patients were included. An adjudicated SSI occurred in 27 patients (17.9%). There was no difference in the rate of any SSI between the 5-day and 1-day antibiotic groups (hazard ratio [HR], 0.92; 95% confidence interval [CI], 0.4 to 1.9; p = 0.82). Antibiotic-related complications occurred in 13 patients (8.6%), with no difference noted between groups (HR, 0.46; 95% CI, 0.2 to 1.4; p = 0.18). A total of 45 patients (29.8%) required a return to the operating room within the first postoperative year, which corresponded with a 68.8% reoperation-free rate of survival at 1 year when accounting for competing risks. The most common reason for reoperation was infection (29 of 45; 64.4%). A total of 7 patients (4.6%) required subsequent amputation of the operative extremity, and an additional 6 patients (4.0%) required implant revision within 12 months. A total of 36 patients (23.8%) developed metastases, and 6 patients (4.0%) developed a local recurrence during the first postoperative year. A total of 11 patients (7.3%) died during the study period. There were no significant differences in oncologic outcomes between the 5-day and 1-day antibiotic groups (HR, 0.97; 95% CI, 0.5-1.8; p = 0.92). CONCLUSIONS: There were no significant differences in surgical or oncologic outcomes between pediatric patients who underwent a 1-day versus 5-day antibiotic regimen following endoprosthetic reconstruction in the PARITY trial. Surgeons should be aware of and counsel patients and caregivers regarding the 30% rate of reoperation and the risks of infection (17.9%), death (7.3%), amputation (4.6%), and implant revision (4%) within the first postoperative year. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Central Adjudication Committee and Clinical Site Investigator Agreement on Outcomes in the PARITY Trial: A Secondary Analysis of the PARITY Trial Data.

BACKGROUND: The detection of a surgical site infection (SSI) in patients with metal implants requires a high degree of clinical acumen. The inherent subjectivity of SSI diagnosis poses a challenge in the design of surgical trials because this subjectivity raises concern for outcome assessment bias. Central Adjudication Committees (CACs) are often utilized to minimize the variability in outcome assessment. Little research has been done to determine the reliability of outcome assessment in trials utilizing a CAC. In the present study, we determined the agreement between the study CAC and the clinical site investigators for the primary and secondary outcome assessments. METHODS: The Prophylactic Antibiotic Regimens in Tumor Surgery (PARITY) trial was a multicenter, blinded, parallel 2-arm, randomized controlled trial that aimed to determine the effect of a 5-day versus 1-day postoperative prophylactic antibiotic regimen on the rate of SSI in patients undergoing surgical excision of tumors in the femur or tibia. The blinded PARITY CAC adjudicated all primary and secondary outcomes identified during the 1-year study follow-up. In the present secondary analysis, the Cohen kappa statistic was utilized to determine the level of agreement. RESULTS: The primary outcome of SSI diagnosis demonstrated a substantial level of agreement between the CAC and the site investigators (0.699; 95% confidence interval [CI], 0.595 to 0.803]). Categorization of the SSI (i.e., superficial, deep, or organ space) showed moderate agreement (0.470; 95% CI, 0.382 to 0.558). Secondary outcomes such as the types of reoperations and the indication for reoperation typically showed substantial to almost perfect agreement, whereas antibiotic-related complications showed fair agreement (0.241; 95% CI, 0.000 to 0.474). CONCLUSIONS: Although there was a substantial level of agreement between the PARITY CAC and site investigators on the diagnosis of an SSI, as well as typically at least substantial agreement on the causes and types of reoperations, there was less agreement regarding the type of SSI and the occurrence of an antibiotic-related complication. Therefore, the CAC appears to have provided value when adjudicating the depth of infection and when determining the causality of medical complications associated with antibiotics. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Chondrosarcoma: A Clinical Review.

Chondrosarcomas are a diverse group of malignant cartilaginous matrix-producing neoplasms. Conventional chondrosarcomas are a continuum of disease based on the biologic activity of the tumor. The tumors range from the relatively biologically benign low-grade tumors or intermediate atypical cartilaginous tumors (ACTs), to malignant, aggressive high-grade tumors. The clinical presentation, radiographic and pathologic findings, treatments and outcomes vary significantly based on the histologic grade of the tumor. Chondrosarcomas present a diagnostic dilemma, particularly in the differentiation between high- and intermediate-grade tumors and that of low-grade tumors from benign enchondromas. A multidisciplinary team at a tertiary sarcoma centre allows for optimal care of these patients.

The Importance of Pragmatic Study Design to the Scholarly Influence of Surgical Hip Fracture Randomized Controlled Trials.

BACKGROUND: Surgical randomized controlled trials (RCTs) have potential drawbacks, leading some to question their role in filling the information gap in orthopaedic surgery. Pragmatism in study design was introduced to increase the clinical applicability of study results. The purpose of this study was to examine how pragmatism affects the scholarly influence of surgical RCTs. METHODS: A search for surgical hip fracture-related RCTs published between 1995 and 2015 was done. Journal impact factor, citation number, research question, significance and type of outcome, number of centers involved, and the Pragmatic-Explanatory Continuum Indicator Summary-2 level of pragmatism score were recorded for each study. Scholarly influence was estimated by a study's inclusion into orthopaedic literature or guidelines or through the study's average yearly citation rate. RESULTS: One hundred sixty RCTs were included in the final analysis. A multivariate logistic regression identified large study sample size as the only predictor of an RCT being used in clinical guidance texts. Large sample size and multicenter RCTs were predictors of high yearly citation rates. The level of pragmatism in study design did not predict scholarly influence. CONCLUSIONS: Pragmatic design is not independently associated with increased scholarly influence; however, large study sample size was the most important study characteristic affecting scholarly influence.

Predictors of Functional Recovery among Musculoskeletal Oncology Patients Undergoing Lower Extremity Endoprosthetic Reconstruction.

BACKGROUND AND OBJECTIVES: Functional outcomes are important for oncology patients undergoing lower extremity reconstruction. The objective of the current study was to describe patient reported function after surgery and identify predictors of postoperative function in musculoskeletal oncology patients undergoing lower extremity endoprosthetic reconstruction. METHODS: We performed a cohort study with functional outcome data from the recently completed Prophylactic Antibiotic Regimens in Tumor Surgery (PARITY) trial. We utilized the 100-point Toronto Extremity Salvage Score (TESS), which was administered pre-operatively and at 3, 6 and 12 months post-operatively. Higher scores indicate better physical functioning, and the minimally important difference is 11 points. We calculated mean functional scores at each timepoint after surgery and developed a logistic regression model to explore predictors of failure to achieve excellent post-operative function (TESS ≥ 80) at 1 year after surgery. RESULTS: The 555 patients included in our cohort showed important functional improvement from pre-surgery to 1 year post-surgery (mean difference 14.9 points, 95%CI 12.2 to 17.6; p < 0.001) and 64% achieved excellent post-operative function. Our adjusted regression model found that poor (TESS 0-39) pre-operative function (odds ratio [OR] 3.3, 95%CI 1.6 to 6.6); absolute risk [AR] 24%, 95%CI 8% to 41.2%), older age (OR per 10-year increase from age 12, 1.32, 95%CI 1.17, 1.49; AR 4.5%, 95%CI 2.4% to 6.6%), and patients undergoing reconstruction for soft-tissue sarcomas (OR 2.3, 95%CI 1.03 to 5.01; AR 15.3%, 95%CI 0.4% to 34.4%), were associated with higher odds of failing to achieve an excellent functional outcome at 1-year follow-up. Patients undergoing reconstruction for giant cell tumors were more likely to achieve an excellent functional outcome post-operatively (OR 0.40, 95%CI 0.17 to 0.95; AR -9.9%, 95%CI -14.4% to -0.7%). CONCLUSIONS: The majority of patients with tumors of the lower extremity undergoing endoprosthetic reconstruction achieved excellent function at 1 year after surgery. Older age, poor pre-operative function, and endoprosthetic reconstruction for soft tissue sarcomas were associated with worse outcomes; reconstruction for giant cell tumors was associated with better post-operative function. LEVEL OF EVIDENCE: Therapeutic Level IV.

Examining patient perspectives on sarcoma surveillance: The Sarcoma Surveillance Survey.

OBJECTIVES: The optimal frequency and modality of sarcoma surveillance imaging are uncertain, and current practices vary substantially. While efforts to develop evidence-based guidelines are ongoing, patient perspectives regarding surveillance imaging have not been reported. The primary goal of this study was to pilot the novel Sarcoma Surveillance Survey to assess patient concerns regarding sarcoma surveillance. METHODS: In this single-center, cross-sectional study, patients receiving surveillance imaging after surgical sarcoma treatment were administered the 10-item Sarcoma Surveillance Survey, the validated Appraisal Scale, measuring positive and negative emotional reactions to imaging, and the Patient-Reported Outcomes Measurement Information System (PROMIS) Anxiety Short Form 8a as a measure of anxiety. RESULTS: Patients expressed highest levels of concern about cost and radiation exposure associated with surveillance, and most (87.6%) did not express a preference for more or less frequent imaging. Younger patients and those living further away from the imaging center were more concerned about cost of surveillance. Female patients had higher levels of concern compared to males regarding radiation, IV contrast, and overall levels of concern about surveillance. Higher levels of anxiety were correlated with preference for more frequent imaging (rs = 0.274, p = 0.027) and higher overall level of concern about surveillance (rs = 0.259, p = 0.037). Higher negative appraisal scores were also correlated with higher overall concerns (rs = 0.323; p = 0.012). CONCLUSIONS: Patient perspectives should be considered when developing sarcoma surveillance strategies. Identifying patients with greater anxiety and concerns regarding imaging may create opportunities for improved surveillance practices as well as counseling and survivorship interventions.

Tourniquet use in patients undergoing tumour resection and endoprosthetic reconstruction of the knee.

AIMS: The aim of this study was to determine the prevalence and impact of tourniquet use in patients undergoing limb salvage surgery with endoprosthetic reconstruction for a tumour around the knee. METHODS: We retrieved data from the Prophylactic Antibiotic Regimens in Tumor Surgery (PARITY) trial; specifically, differences in baseline characteristics, surgical details, and postoperative functional outcomes between patients who had undergone surgery under tourniquet and those who had not. A linear regression model was created to evaluate the impact of tourniquet use on postoperative Toronto Extremity Salvage Scores (TESSs) while controlling for confounding variables. A negative-binomial regression model was constructed to explore predictors of postoperative length of stay (LOS). RESULTS: Of the 604 patients enrolled in the PARITY trial, 421 had tumours around the knee joint, of whom 225 (53%) underwent surgery under tourniquet. The tourniquet group was younger (p = 0.014), more likely to undergo surgery for a tumour of the tibia, and had shorter operating times by a mean of 50 minutes (95% confidence interval 30 to 72; p < 0.001). The adjusted linear regression model found that the use of a tourniquet, a shorter operating time, and a higher baseline TESS independently predicted better function at both three- and six-month follow-up. The negative-binomial regression model showed that tourniquet use, shorter operating time, younger age, and intraoperative tranexamic acid administration independently predicted a shorter LOS in hospital. CONCLUSION: The results of this study show that in patients undergoing resection of a tumour around the knee and endoprosthetic reconstruction, the use of an intraoperative tourniquet is associated with a shorter operating time, a reduced length of stay in hospital, and a better early functional outcome.Cite this article: Bone Joint J 2022;104-B(10):1168-1173.

Defining Minimally Important Differences in Functional Outcomes in Musculoskeletal Oncology.

BACKGROUND: Functional outcomes are commonly reported in studies of patients undergoing limb-salvage surgery for the treatment of musculoskeletal tumors; however, interpretation requires knowledge of the smallest amount of improvement that is important to patients: the minimally important difference (MID). We established the MIDs for the Musculoskeletal Tumor Society Rating Scale-93 (MSTS-93) and Toronto Extremity Salvage Score (TESS) for patients with bone tumors undergoing lower-extremity endoprosthetic reconstruction. METHODS: This study was a secondary analysis of the recently completed PARITY (Prophylactic Antibiotic Regimens in Tumor Surgery) study. We used MSTS-93 and TESS data from this trial to calculate (1) the anchor-based MIDs with use of an overall function scale and a receiver operating characteristic curve analysis and (2) the distribution-based MIDs based on one-half of the standard deviation of the change scores from baseline to the 12-month follow-up and one-half the standard deviation of baseline scores. RESULTS: Five hundred and ninety-one patients were available for analysis. The Pearson correlation coefficients for the association between changes in MSTS-93 and TESS scores and changes in the external anchor scores were 0.71 and 0.57, indicating high and moderate correlations. The anchor-based MID was 12 points for the MSTS-93 and 11 points for the TESS. Distribution-based MIDs were larger: 16 to 17 points for the MSTS-93 and 14 points for the TESS. CONCLUSIONS: Two methods for determining MIDs for the MSTS-93 and TESS for patients undergoing lower-extremity endoprosthetic reconstruction for musculoskeletal tumors yielded quantitatively different results. We suggest the use of anchor-based MIDs, which are grounded in changes in functional status that are meaningful to patients. These thresholds can facilitate responder analyses and indicate whether significant differences following interventions are clinically important to patients. LEVEL OF EVIDENCE: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.