The study was performed by the ethical standards of the Declaration of Helsinki. All patients provided informed consent before inclusion in the study. After approval from the Institutional Review Board, 52 surgically treated patients with LGCS, between March 2007 and May 2019, were retrospectively examined using clinical, surgical, and radiographic records from the senior surgeon’s operating room. A hand search of operating room logs was performed for the records with the following terms: “enchondroma,’’ ‘’low-grade chondrosarcoma,’’ and “’grade 1 chondrosarcoma.” The diagnosis of LGCS was made with the recent onset of emerging pain, endosteal scalloping in radiology, and significant uptake on single-photon emission computed tomography/computed tomography, and finally was confirmed with a postoperative pathology report. Sixty-nine patients (69 tumors) were diagnosed with LGCS. Nine patients were lost to follow-up during a mean follow-up period of 2.9 years (range 2–5 years). All of them were treated with intralesional curettage ± cementation/graft or wide local excision (WLE). None of these had a postoperative complication. No local recurrence or metastases was confirmed in these nine patients. At the last follow-up, their MSTS score was 26.7 ± 2.3. Eight patients were lost to follow-up due to death for other reasons (last follow-up at 32.3 ± 5.7 months). Therefore, the final cohort included 52 patients (52 tumors), with a minimum follow-up of 24 months and a mean follow-up of 72.92 ± 39.13 months. Following diagnosis, the patients were operated on with intralesional curettage (IC) for long bones or WLE for axial bones. For IC, allograft/cancellous autograft or cement was used. IC was supported with a high-speed burr and phenol as adjuvant therapy. Following surgery, all patients received physiotherapy to obtain a full range of motion. The histopathologic diagnosis was made using the principles of Mirra et al., and the radiologic diagnosis was made using the principles of Murphey et al. [1,21]. The radiologic criteria were the evidence of endosteal scalloping, absent of cortical destruction/soft tissue mass on magnetic resonance imaging (MRI). On scintigraphy, the uptake of the lesion was greater than the spina iliaca anterior superior. The indications for surgery were radiographically low-grade cartilage tumor with pain/progressive enlargement or endosteal scalloping. The diagnosis was made with multidisciplinary approach including a musculoskeletal radiologist and pathologist. The retrieved data included demographics, tumor location, surgical treatment type, local adjuvants, complications, Musculoskeletal Tumor Society (MSTS) scores , and local recurrence. The follow-up was done every 3 months for the first year and annually for the following years. No patient had a metastatic disease or died because of chondrosarcoma.
Statistical analysis: Descriptive statistics were used to describe continuous variables (mean, standard deviation, minimum, median, and maximum). Independent variables with normal distribution were compared using the Student t test, while independent variables with non-normal distributions were compared using the Mann–Whitney U test. Two independent variables with non-normal distribution were compared using one-way analysis of variance, while two independent variables with normal distribution were compared using the Kruskal–Wallis test. The chi-square or Fisher exact test was used to examine the relationship between categorical variables. Pearson correlation was used in correlation analyses for normally distributed variables, while Spearman's rho correlation analysis was used for continuous variables with a non-normal distribution. Analyses were performed using the MedCalc Statistical Software (version 12.7.7) (MedCalc Software BVBA, Ostend, Belgium; http://www.medcalc.org).