Surgical Treatment and Proposed Modified Classification for Harrington Class III Periacetabular Metastases

Area of Science:

• Orthopedic Surgery
• Oncology
• Reconstructive Surgery

Background:

• The Harrington classification system is used for hip lesions.
• Class III lesions present challenges in surgical management and outcome prediction.
• Existing classification may not adequately guide surgical strategy for complex cases.

Purpose of the Study:

• To evaluate outcomes of Harrington class III lesions treated with the standard classification.
• To propose a modified surgical classification for Harrington class III lesions.
• To assess the efficacy of the modified classification in improving patient outcomes.

Main Methods:

• Retrospective review of 16 patients (Phase 1) to develop a modified classification.
• Prospective study of 62 patients (Phase 2) treated with the modified classification.
• Assessment of functional outcomes using the Musculoskeletal Tumor Society (MSTS) 93 score.
• Evaluation of local control via 2-year recurrence-free survival (RFS).

Main Results:

• The modified classification identified subgroups IIIa and IIIb based on bone destruction extent.
• Subgroup IIIb showed significantly longer surgical times, increased hemorrhage, poorer functional outcomes, and less favorable local control compared to IIIa.
• Phase 2 patients treated with the modified classification demonstrated reduced surgical time, less hemorrhage, improved MSTS 93 scores, and higher 2-year RFS rates.

Conclusions:

• The original Harrington classification is insufficient for managing class III lesions.
• The proposed modified classification, incorporating subgroups and tailored surgical strategies, effectively addresses Harrington class III lesions.
• This modification leads to significant improvements in functional outcomes and local control, with manageable surgical complexity.