J Korean Orthop Assoc.  2024 Dec;59(6):422-430. 10.4055/jkoa.2024.59.6.422 .

Radiographic Outcomes of Cortical Atrophy Associated with Tumor Prosthesis: A Retrospective Review in Adult Patients

• Kim CS
• Sung KH
• Chung SH

• KMID: 2562670
• DOI: http://doi.org/10.4055/jkoa.2024.59.6.422

Abstract

Purpose
Few studies have been conducted on the level of cortical atrophy and whether its incidence increases according to the surgical site. Therefore, this study compared the reduction ratio of cortical atrophy at each stem level and the incidence rates of cortical atrophy at the surgical sites.
Materials and Methods
This study retrospectively reviewed 45 stems (17 on the tibia, three on the humerus, and 25 on the femur) from 29 patients who underwent a wide excision of malignant bone or soft tissue tumors with tumor prosthesis surgery, from January 2008 to January 2023. The cortical thickness was measured using plain radiographs in the anteroposterior and lateral views along each stem level, with intervals close to a year.
Results
The mean patient age was 55.0 years (range, 21.0–79.0 years), and the mean follow-up period was 4.1 years (range, 1.3–12.5 years). Grade 1 cortical atrophy (20%–50% reduction) was observed in 19 stems (nine stems on the tibia, two stems on the humerus, and eight stems on the femur), of which 10 were non-cement, and nine were cement within an average of 2.24 years. Grade 2 cortical atrophy (>50% reduction) was observed in three of 19 stems, two of which eventually developed from grade 1 cortical atrophy within an average of 3.19 years. Fourteen stems showed cortical atrophy 1 cm below the resection level. In contrast, four, three, and two stems showed cortical atrophy at the midline level of the stem, the tip of the stem, and the end of the cement line, respectively. The reduction ratios of the bone length between the atrophic and non-atrophic groups were 43.3% and 43.6%, respectively, and no significant difference was observed between the groups.
Conclusion
Depending on the specific stem level, cortical atrophy can be observed more frequently in a specific period, but it is not observed more frequently according to the resection site, resection length, or use of cemented or non-cemented stems. Care should be taken to monitor cortical atrophy to prevent prosthetic failure, and the expansion of tumor prosthesis surgery should be achieved through a large multicenter prospective study to gain additional insights.

Keyword

tumor; failure; cortical atrophy; tumor prosthesis