Outcomes of Surgical Reconstruction Using Custom 3D-Printed Porous Titanium Implants for Critical-Sized Bone Defects of the Foot and Ankle

Abstract

Background: Treating critically sized defects (CSDs) of bone remains a significant challenge in foot and ankle surgery. Custom 3D-printed implants are being offered to a small but growing subset of patients as a salvage procedure in lieu of traditional alternates such as structural allografts after the patient has failed prior procedures. The long-term outcomes of 3D-printed implants are still unknown and understudied because of the limited number of cases and short follow-up durations. The purpose of this study was to evaluate the outcomes of patients who received custom 3D-printed implants to treat CSDs of the foot and ankle in an attempt to aid surgeons in selecting appropriate surgical candidates. Methods: This was a retrospective study to assess surgical outcomes of patients who underwent implantation of a custom 3D-printed implant made with medical-grade titanium alloy powder (Ti-6Al-4V) to treat CSDs of the foot and ankle between June 1, 2014, and September 30, 2019. All patients had failed previous nonoperative or operative management before proceeding with treatment with a custom 3D-printed implant. Univariate and multivariate odds ratios (ORs) of a secondary surgery and implant removal were calculated for perioperative variables. Results: There were 39 cases of patients who received a custom 3D-printed implant with at least 1 year of follow-up. The mean follow-up time was 27.0 (12-74) months. Thirteen of 39 cases (33.3%) required a secondary surgery and 10 of 39 (25.6%) required removal of the implant because of septic nonunion (6/10) or aseptic nonunion (4/10). The mean time to secondary surgery was 10 months (1-22). Multivariate logistic regression revealed that patients with neuropathy were more likely to require a secondary surgery with an OR of 5.76 ( P = .03). Conclusion: This study demonstrated that 74% of patients who received a custom 3D-printed implant for CSDs did not require as subsequent surgery (minimum of 1-year follow-up). Neuropathy was significantly associated with the need for a secondary surgery. This is the largest series to date demonstrating the efficacy of 3D-printed custom titanium implants. As the number of cases using patient-specific 3D-printed titanium implant increases, larger cohorts of patients should be studied to identify other high-risk groups and possible interventions to improve surgical outcomes. Level of Evidence: Level IV, case series.

What’s New in Foot and Ankle Surgery

“…All cases were performed by a single, experienced surgeon. In a study of 39 cases that utilized 3-D printed, porous-coated titanium implants for critical osseous defects of the hindfoot and/or ankle, Abar et al 38 found that 33% of cases required secondary procedures and 26% of cases required removal of the implant for septic or aseptic nonunion. These outcomes are at least similar to or better than previous findings using bulk allograft for these difficult cases.…”

Smart stimuli-responsive strategies for titanium implant functionalization in bone regeneration and therapeutics

“…17 Though tremendous efforts have been made, it is far from rare to encounter failed titanium implantation in clinical practice due to insufficient osseointegration, which demands secondary surgical intervention, thus causing considerable pain and financial burdens to patients. [18][19][20] In most cases, the failure could be ascribed to the incompatibility between implants and the specific microenvironment of bone defects, especially in pathological conditions, such as bacterial infection, chronic inflammation, tumor, diabetes mellitus, etc. Therefore, titanium implants with functionalized surfaces for repairing bone defects in pathological microenvironments are desiderated, which could, on the one hand, reverse the specific pathological microenvironment, and on the other hand, promote bone regeneration.…”

“…17 Though tremendous efforts have been made, it is far from rare to encounter failed titanium implantation in clinical practice due to insufficient osseointegration, which demands secondary surgical intervention, thus causing considerable pain and financial burdens to patients. 18–20…”

Indications for Nonbiological Reconstruction of Posttraumatic Bone Defects About the Knee

“…3,[10][11][12][13] Our assumption is that 3D printing and modeling now plays an important role in many of the more complex orthopaedic cases currently treated around the world. This is most evident in the realm of adult reconstructive surgery 7,12 and joint arthroplasty 3,[13][14][15][16] but has now essentially permeated every aspect of orthopaedic surgery, including trauma, 4,8,[17][18][19][20] spine, 21,22 hand, 8,20,23 shoulder, 6,9 tumor, 5,24 and sports medicine. 9 This review describes and illustrates several cases where patient-specific 3D-printed titanium scaffolds were used.…”