Efficacy of a Modified Scoring System to Facilitate Surgical Decision-making for Diaphyseal Malignancies: When is Devitalized Tumor-bearing Autograft of Value?

OBJECTIVES

To evaluate the validity of a modified scoring system (MSS) for inferring the bony quality of tumor-bearing diaphyses and predicting the risk of reconstructive failure after devitalized bone replantation (DBR).

METHODS

In this retrospective cohort study, we reviewed the records of 30 patients surgically treated for diaphyseal malignancies between 1996 and 2015. There were 18 male and 12 female subjects; the average age was 34.0 ± 24.5 years (8-82 years). Tumor locations comprised the femur (21), the humerus (4), the tibia (3), the radius (1), and the fibula (1). Histological diagnoses included osteosarcoma (13), metastases (4), Ewing sarcoma (3), chondrosarcoma (3), malignant fibrohistiocytoma (2), periosteal osteosarcoma (1), Langerhans cell sarcoma (1), lymphoma (1), rhabdomyosarcoma (1), and malignant giant cell tumor (1). All primary tumors were rated as stage IIB. Twenty patients underwent DBR. Prosthetic procedures and segmental autografting/allografting were performed in 7 and 3 cases, respectively. MSS (comprising 5 elements: pain, tumor location, bone destruction, localized dimension, and longitudinal dimension) for each patient was calculated in accordance with their preoperative presentations. Outcome measurements included oncological results, outcomes of reconstructions, complications, and functional preservation, presented using the musculoskeletal tumor society (MSTS) scale.

RESULTS

Follow up was available in 29 cases for an average duration of 61.0 ± 49.9 months (12-152 months). Infection occurred in 2 patients (6.9%), primary nonunion in 6 (27.3%), metastases in 9 (31.9%), recurrences in 4 (13.8%), and deaths in 7 (24.1%); 1 subject underwent amputation due to recurrence following endoprosthetic replacement (3.4%). In the DBR group, fractures occurred in 4 cases (21.1%) and nonunion in 5 (25%); internal fixation was related to nonunion (nails, 44.4% vs plates, 9.1%, P = 0.02). MSS was associated with fractures of devitalized autografts (11.0 ± 1.2 vs 8.3 ± 1.8, P = 0.01); the system was efficacious in predicting chances of fractures of these grafts (P = 0.02). MSS ≥ 10 (with false positive rate ≤ 6.7%) suggested increased fracture probability (≥22.7%) after DBR; therefore, 10 was considered a cutoff value.

CONCLUSIONS

Diaphyseal malignancies with MSS ≥10 may contraindicate DBR for increased chances of reconstructive failure. In this situation, alternative procedures are advisable. Further investigations are warranted to assess the efficacy of MSS in implying the validity of DBR for diaphyseal malignancies.