Clinical and Radiographic Outcomes of a Long Cementless Monobloc Stem for Revision Total Hip Arthroplasty Due to Chronic Periprosthetic Infection

Background: A long cementless monobloc stem is widely used for aseptic loosening, with satisfactory 5- to-10-year outcomes reported. Nonetheless, related studies on chronic periprosthetic joint infection (PJI) are scant. This study evaluated the clinical and radiographic outcomes of the stem in 2-stage revisions due to PJI.

Methods: This prospective multicenter cohort study consisted of patients from three medical centers who were enrolled in a single arm from January 2017 to May 2022. All patients were diagnosed with chronic PJI based on the International Consensus Meeting criteria and underwent 2-stage revisions using a long monobloc cementless revision stem. Among 44 patients, 37 (12 women and 25 men) completed an average follow-up of 35.6 months (range, 14 to 75). The primary outcome was the stability of the stem; secondary outcomes included infection eradication, Harris Hip Score, leg length discrepancy, major complications, and isolated pathogens at intraoperative cultures.

Results: At 1 year after revision, the infection-free prosthesis survival rate was 97.3% (95% confidence interval: 96.4 to 98.2). At the last follow-up, the mean subsidence was 2.9 ± 2.1 mm (range, 0.8 to 4.8). Postoperative leg length discrepancy averaged -4.6 ± 4.9 mm (range, -16 to 0). The Engh score averaged 14.1 ± 6.9 (range, zero to 22). The Harris Hip Score improved from a preoperative average of 35.7 ± 8.5 (range, 12 to 50) to 80.4 ± 9.3 (range, 58 to 92) at the 1-year postoperative follow-up (P < 0.01).

Conclusions: The long cementless monobloc stem used in the current study presents a feasible option for 2-stage revision in cases of chronic PJI. The bone ingrowth and stability could be observed within the short follow-up time.

Level of evidence: Level IV, prospective cohort study.