Long-term results of the Global Modular Replacement System tumor prosthesis for reconstruction after limb-sparing bone resections in orthopedic oncologic conditions: Results from a national cohort.

BACKGROUND AND OBJECTIVES: We investigated implant revision, implant failure, and amputation risk after limb-sparing bone tumor surgery using the Global Modular Replacement System (GMRS) tumor prosthesis in patients suffering from bone sarcomas (BS), giant cell tumors (GCT), or metastatic bone disease (MBD). MATERIAL AND METHODS: A retrospective study of a nationwide consecutive cohort (n = 119, 47 [12-81] years, M/F = 65/54) having limb-sparing surgery and reconstruction using the GMRS tumor prosthesis due to bone tumors (BS/GCT/MBD = 70/8/41) from 2005 to 2013. Anatomical locations were as followed: distal femur (n = 49), proximal femur (n = 41), proximal tibia (n = 26), or total femur (n = 3). Kaplan-Meier survival analysis and competing risk analysis with death as a competing risk were used for statistical analysis. RESULTS: For BS and GCT patients, 5-year patient survival was 72% (95% confidence interval [CI]: 59-85%) and for MBD 33% (95% CI: 19-48%). Thirty-two patients underwent revision surgery (5-year revision incidence 14%; 95% CI: 8-21%). Twelve patients had revision of bone-anchored parts (implant failure) with a 5-year revision incidence 6% (95% CI: 2-10%). Ten amputations were performed due to local relapse (n = 9) or recurrent infections (n = 1) with a 5-year incidence of amputation: 8% (95% CI: 3-13%). CONCLUSIONS: We identified a low risk of revision and amputation when using the GMRS tumor prosthesis for limb-sparing bone tumor.

Validity and Reliability Evaluation of Four Commercial Activity Trackers' Step Counting Performance.

INTRODUCTION: Activity trackers are useful tools for physical rehabilitation purposes. Most available activity trackers are designed for fitness and wellness use, lacking in both accuracy and precision at lower speeds. Validity and reliability at all clinically relevant speeds are crucial selection criteria for use in clinical practice. The aim of this study was to assess the validity and reliability of four consumer-based activity trackers at clinical relevant walking speeds for patient groups undergoing rehabilitation. METHODS: The four commercial activity trackers Fitbit Surge (FS), Fitbit Charge HR (FC), Microsoft Band 2 (MB), and A&D 101NFC Activity Monitor (A&D) were evaluated at 2, 4, 4.5, and 5.5 km/h. Twenty healthy participants aged 25.6 ± 2 years walked on a treadmill at the four velocities in two trials of 100 steps each. Mean average percentage error (MAPE), intraclass correlation coefficient (ICC), and Bland-Altman 95% limits of agreement were calculated to assess validity and reliability. RESULTS: MAPE levels were between -8% and -6% for FS, -15% and 0% for MB, 7% and 21% for FC, and -53% and 1% for AD. The biggest inaccuracies were seen at 2 km/h, where AD underestimated by 53%. The highest accuracy was predominantly found with MB and AD, which overestimated ≤2% at velocities ≥4 km/h. ICC was moderate (0.73) for FS, good (0.88) for MB, moderate (0.52) for FC, and excellent (0.98) for AD. CONCLUSIONS: MB, FS, and AD accurately counted steps, when participants walked with velocities corresponding to a brisk walk (≥4 km/h). Walking at lower speeds (≤2 km/h) was not counted accurately. Thus, the four evaluated activity trackers are not useful for patient groups walking at lower speeds during rehabilitation, nor for counting indoor walking.

Factors associated with reduced functional outcome and quality of life in patients having limb-sparing surgery for soft tissue sarcomas - a national multicenter study of 128 patients.

BACKGROUND: Limb-sparing surgery for sarcomas has become possible in most cases. However, the impact of the procedure on the functional outcome has only been investigated in a few studies. The aim of this study has been to identify tumor- and patient-related factors associated with reduced functional outcome and quality of life after limb-sparing surgery in soft tissue sarcoma patients. MATERIAL AND METHODS: In total, 128 patients (mean age = 58, female/male = 54/74) who were treated with limb-sparing surgery without bone resection for soft tissue sarcomas in Denmark during the period 1 January 2009 to 31 December 2011 were included. Patients were asked to participate at least one year after surgery, and patients who had experienced local recurrence or metastatic disease were excluded. The Toronto Extremity Salvage Score (TESS) measured functional disability, while the Musculoskeletal Tumor Society Score (MSTS) measured functional impairment. European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 measured quality of life. Tumor- and patient-related factors (age, gender, tumor depth, tumor size, malignancy, comorbidity, location, and radiotherapy) were extracted from the Danish National Sarcoma Database. Wilcoxon rank-sum test and Kruskal-Wallis were used for univariable analysis. Adjusted odds ratios were estimated by using multiple logistic regression models. RESULTS: In the multiple regression analysis, it was found that female gender (p = 0.03), lower extremity tumors (p < 0.01) and radiotherapy (p = 0.02) resulted in an increased risk of a lower TESS score. Initial reduced postoperative function was found to be associated with a lower functional outcome. Patients with reduced functional outcome have increased risk for reduced quality of life (p < 0.01). CONCLUSION: The results of this study show that patient- and tumor-related factors have an important role in the functional outcome.

Changes in Functional Outcome and Quality of Life in Soft Tissue Sarcoma Patients within the First Year after Surgery: A Prospective Observational Study.

Soft tissue sarcoma (STS) patients undergoing surgery may experience reduced functional outcome (FO) and quality of life (QoL) compared to the general population. The aim of this study was to evaluate the development of FO and QoL in patients with STS in the extremities within the first year after first-time limb-sparing surgery. Twenty-nine out of 40 eligible patients were included in the present study. QoL and FO were evaluated by questionnaires while FO was also evaluated by objective tests. Patients were assessed before surgery and at fixed time points within the first year after surgery. Patients with STS in the extremities had an average strength of 82.34% (95% CI: 68.57-96.11) of the expected strength at one year post surgery. Multivariate, repeated ANOVA showed statistically significant reductions in strength in the disease-affected extremity when compared with the healthy side after surgery. Multivariate, repeated ANOVA showed a statistically significant improvement in FO and QoL within the first year post surgery. Limb-sparing surgery for STS significantly reduced strength in the disease-affected extremity and generally reduced FO and QoL in the first months after surgery. Improvements were observed for FO and QoL at one year after surgery.

Validation of the Danish version of the musculoskeletal tumour society score questionnaire.

BACKGROUND: The musculoskeletal tumour society score (MSTS) is a well-known questionnaire for measuring functional outcome in patients with neoplasms in the extremities. Standardized guidelines for cross-cultural translation and validation ensure the equivalence of content between the original and translated versions. The translation and validation provide the possibility to compare different sarcoma populations on an international level. This study is based on the hypothesis that the Danish MSTS questionnaire is a valid tool for measuring the end result after surgery for neoplasms in the extremities. AIM: To validate the Danish version of the upper and lower extremity version of the MSTS. METHODS: The translation of the MSTS was conducted in accordance with international guidelines. Patients operated for sarcomas and aggressive benign tumors were invited to participate in the study. The psychometric properties of the Danish version of the MSTS were tested in terms of validity and reliability and for the risk of floor or ceiling effect. Spearman's rank coefficient was used to test the validity by comparing with the Toronto Extremity Salvage Score (TESS). The Intraclass Correlation Coefficient (ICC) was used to evaluate inter-rater reliability. Cronbach's alpha was used to test for internal consistency. Spearman's rank coefficient was used to compare the MSTS lower extremity version with the objective test, Timed Up and Go (TUG). RESULTS: The upper extremity version demonstrated an ICC of 0.95 in the inter-rater reliability test. The lower extremity version had an ICC of 0.88 in the inter-rater reliability test, respectively. Both MSTS versions showed a ceiling effect. The validity of the MSTS was measured by Spearman's rank correlation coefficient by comparing the MSTS with the TESS and found it to be of 0.80 (P < 0.01) and 0.83 (P < 0.01) for the upper extremity and lower extremity version, respectively. A Spearman's rank correlation coefficient of - 0.26 (P < 0.01) was found between the TUG and the MSTS questionnaire. A Spearman's rank correlation coefficient of - 0.38 (P < 0.01) was found between the TUG and the lower extremity version of the TESS questionnaire. CONCLUSION: The Danish version of the MSTS questionnaires were found to have good reliability and validity, however a substantial ceiling effect was identified.

Validation of a Danish version of the Toronto Extremity Salvage Score questionnaire for patients with sarcoma in the extremities.

INTRODUCTION: The Toronto Extremity Salvage Score (TESS) questionnaire is a self-administered questionnaire designed to assess physical disability in patients having undergone surgery of the extremities. The aim of this study was to validate a Danish translation of the TESS. MATERIAL AND METHODS: The TESS was translated according to international guidelines. A total of 22 consecutive patients attending the regular outpatient control programme were recruited for the study. To test their understanding of the questionnaires, they were asked to describe the meaning of five randomly selected questions from the TESS. The psychometric properties of the Danish version of TESS were tested for validity and reliability. To assess the test-retest reliability, the patients filled in an extra TESS questionnaire one week after they had completed the first one. RESULTS: Patients showed good understanding of the questionnaire. There was a good internal consistency for both the upper and lower questionnaire measured by Cronbach's alpha. A Bland-Altman plot showed acceptable limits of agreement for both questionnaires in the test-retest. There was also good intraclass correlation coefficients for both questionnaires. The validity expressed as Spearman's rank correlation coefficient comparing the TESS with the QLQ-C30 was 0.89 and 0.90 for the questionnaire on upper and lower extremities, respectively. CONCLUSION: The psychometric properties of the Danish TESS showed good validity and reliability. FUNDING: not relevant. TRIAL REGISTRATION: not relevant.