Use of 3D Printed Bone Plate in Novel Technique to Surgically Correct Hallux Valgus Deformities

Abstract

Three-dimensional (3-D) printing offers many potential advantages in designing and manufacturing plating systems for foot and ankle procedures that involve small, geometrically complex bony anatomy. Here, we describe the design and clinical use of a Ti-6Al-4V ELI bone plate (FastForward™ Bone Tether Plate, MedShape, Inc., Atlanta, GA) manufactured through 3-D printing processes. The plate protects the second metatarsal when tethering suture tape between the first and second metatarsals and is a part of a new procedure that corrects hallux valgus (bunion) deformities without relying on doing an osteotomy or fusion procedure. The surgical technique and two clinical cases describing the use of this procedure with the 3-D printed bone plate are presented within.

Keywords: 3-D printing; bone plate; bone tether plate; bunion; fastforward; hallux valgus; metatarsus primus adductus varus; titanium.

Figure 1

Diagram showing the components of the FastForward procedure. The 3-D printed plate rests on the lateral side of the second metatarsal and retains the suture tape around the bone while shielding it from tape friction and tension. Two PEEK interference screws are used to fixate the tape in the first metatarsal (Inset image).

Figure 2

Fatigue life curve of cast, polished SLM, and unpolished SLM Ti-6Al-4V ELI. Black arrow denotes tests that were stopped due to run-out.

Figure 3

Illustration of 3-D printed Ti-6Al-4V ELI plate showing the features that were incorporated into the design by using 3-D printing techniques.

Figure 4

Images of (A) Mini-TightRope affixed in “second metatarsal” sawbone and (B) 3-D printed plate and suture wrapped around second metatarsal, per the FastForward procedure, and loaded in the mechanical testing setup.

Figure 5

Biomechanical comparison of the 3-D printed plate with suture tape (the FastForward procedure), suture tape tied in knot, and the Mini-TightRope. Values represent the average (+/− standard deviation) load required to break the second metatarsal.

Figure 6

Surgical photos showing the key steps in the FastForward procedure: (A) Suture tape is passed underneath the second metatarsal, (B) the tape is fed through the channel on the 3-D printed plate, (C) the plate is placed on the lateral side of the second metatarsal and the tape is looped into a cow hitch knot, (D) after drilling two holes in the first metatarsal, the tape is passed across the first-second intermetatarsal space using a suture lasso, and (E) two screws are inserted to fixate the tape inside the first metatarsal.

Figure 7

(A) Pre-operative and (B) 11-month post-operative anteroposterior (AP) radiographs of a 16 year-old female who underwent the FastForward procedure for a moderate congenital hallux valgus deformity.

Figure 8

(A) Pre-operative and (B) 12-week post-operative weight bearing anteroposterior (AP) radiographs of a 64 year-old female with rheumatoid arthritis who underwent the FastForward procedure for a moderate hallux valgus deformity in addition to fifth metatarsal osteotomy for severe bunionette deformity.