Lumbar functional evaluation of pelvic bone sarcomas after surgical resection and spinal pelvic fixation: A clinical study of 304 cases

Abstract

Aims: We endeavored to introduce a novel scoring system (Lumbar Functional Index, LFI) capable of evaluating lumbar function in pelvic bone sarcoma patients who underwent surgical resection and spinal pelvic fixation, while simultaneously identifying the incidence, outcomes, and risk factors of lumbar function impairment among these populations.

Patients and methods: A cohort of 304 primary bone sarcoma patients were recruited. The LFI was created based on the Oswestry Dysfunction Index (ODI) and Japanese Orthopaedic Association (JOA) scores. Lumbar function impairment was defined as LFI score ≥ 18 points, which was identified as high LFI. Demographic data, clinical characteristics, and oncological outcomes were analyzed.

Results: The cohort included chondrosarcoma (39.8%), osteosarcoma (29.9%), Ewing sarcoma (8.6%), bone-derived undifferentiated pleomorphic sarcoma (7.2%), giant cell tumor of bone (7.2%), chordoma (2.3%), and other bone sarcomas (5.0%). The LFI score exhibited significant negative correlation with common scoring systems of bone sarcoma. The incidence of high LFI was 23.0%. Patients with high LFI demonstrated a higher prevalence of type I + II + III + IV pelvic tumor, more sacrificed nerve roots and bilateral lumbar spine fixation during surgery, while lower percentage of R0 resection and local control of pelvic tumor. Decreased median overall survival (30 vs. 52 months, p < 0.001) and recurrence-free survival (14 vs. 24 months, p < 0.001) time were observed in these patients. Type I + II + III + IV pelvic tumor and sacrificed nerve roots≥2 were identified as risk factors for high LFI, while R0 resection and local control were identified as protective factors.

Conclusion: The LFI scoring system exhibited a significant negative correlation to current scoring systems. High LFI patients had worse prognosis and distinct characteristics. The risk factors of high LFI included type I + II + III + IV pelvic tumor and sacrificed nerve roots≥2, and the protective factors included R0 resection and local control.

Keywords: bone sarcomas; functional outcomes; lumbar functional index; pelvis; spinal pelvic fixation.

FIGURE 1

Scatterplot of the distribution of the LFI score and reference scores. (A) The LFI and the PROMIS scores. (B) The LFI and the TESS scores. (C) The LFI and the MSTS scores. All data exhibited a significant negative correlation between the LFI score and reference scores. *p‐value <0.05.

FIGURE 2

Kaplan–Meier curves with the log‐rank test of the overall (A) and recurrence‐free (B) survival of patients with low LFI compared with high LFI.

FIGURE 3

Relationship of the LFI score for each patient (A) and proportion of high LFI among the whole cohort (B) over time. ***, p‐value<0.001.

FIGURE 4

Multivariate analysis of logistic regression of high LFI. Type of pelvic tumor and sacrificed nerve roots≥2 were risk factors for patients having high LFI (A), while protective factors included R0 resection and local control (B). * means p value<0.05.