Clinical Outcomes of Custom 3D-Printed Porous Metallic Implants for Reconstruction of Critical-Sized Bone Defects in the Ankle

Abstract

Background:

Critical-sized defects (CSDs) of bone in the foot and ankle pose substantial surgical challenges because of high complication and failure rates. Three-dimensional (3D)-printed porous metallic implants (custom cages) have emerged as a potential alternative to traditional reconstruction techniques, offering theoretical advantages in stability and integration. However, current literature is limited by small sample sizes and short follow-up. This study reports the largest single-surgeon cohort to date, evaluating outcomes and complications of custom cage arthrodesis.

Methods:

A retrospective cohort study was performed on patients who underwent custom cage implant ankle arthrodesis. The primary outcome was reoperation for any reason. Demographic and perioperative data were extracted for each patient. Univariable and multivariable linear regression analyses were used to assess associations between reoperation and factors including body mass index (BMI), comorbidities, surgical history, and defect size.

Results:

Fifty-three patients were included in this study over a median follow-up of 620 days. At last follow-up, 83% of implants remained in situ and the nonunion rate was 15% at 1 year. Within the overall cohort, 19 patients (36%) required at least 1 reoperation. Of these 19 patients, 8 (42%) developed deep postoperative infection and 5 (26%) ultimately required below-knee amputation. Within the multivariable regression, prior ipsilateral limb infection (OR = 14.9, P = .01) was significantly associated with reoperation.

Conclusion:

Custom cage ankle arthrodesis in this study achieved a relatively high overall fusion rate but was associated with a high complication rate. Deep postoperative infection was a major barrier to a successful outcome. As the use of custom cage arthrodesis increases, evaluation of outcomes and comparison to conventional treatments will be essential to advance CSD treatment in foot and ankle surgery.