Hammertoe deformities are one of the most common foot deformities, estimated to affect one third of the population.¹ Intramedullary implants have gained popularity over the past decade, with the advantage of avoiding an external, percutanous K-wire during the rehabilitation phase. There are many on the market, manufactured from a variety of implant materials including conventional titanium, radiolucent PEEK, absorbable biomaterials, allograft bone, or dynamic shape memory materials. An ideal device would provide the necessary stability for primary healing and eventually be incorporated with surrounding bone eliminating any foreign material in the patient’s body.

Presentation

For this patient, the OSSIOfiber^® Hammertoe Fixation Implant was chosen as the primary fixation for the PIP fusion due to its ability to provide the neccessary stabilization and subsequent bone integration to achieve fusion.

58 year old female presents with a painful hammertoe deformity on second ray. Conservative measures were exhausted and a surgical correction with PIPJ fusion for the rigid hammertoe was chosen.

IMPLANT: OSSIOfiber^® Hammertoe Fixation Implant, 2.9x19mm, 0o angulation

INSTRUMENTATION: Sterile, Disposable Hammertoe Instrumentation (k-wire, medium drill bit, and inserter)

PRE-OP PLANNING: Patient’s toe size is assessed for implant sizing.

Surgical Technique

1. JOINT PREPARATION: After joint exposure, the PIP joint is prepared for arthrodesis. Resecting a small amount of bone when possible, especially with the intermediate phalanx, will minimize toe shortening (Figure 1).

2. PILOT HOLE CREATION: A 0.062” K-wire (included in kit) is used to drill a pilot hole into the center of the canal of both bones to the depth of the opposite cortex (Figure 2a and 2b).

3. TUNNEL CREATION: Tunnels following the k-wire pilot holes are created in the proximal and intermediate phalanx with the provided drill bit. Bury the reference laser lines on the drill bit in the canal to ensure proper depth (Figure 3a and 3b).

Technique Tip: If the intermediate phalanx is short, drill past the second laser line in the proximal phalanx to further bury the proximal side of the implant.

4. IMPLANT INSERTION: Mount the wider, shorter (distal) side of the OSSIOfiber^® implant onto the provided inserter. The proximal end of the OSSIOfiber^® implant is inserted into the proximal phalanx with steady, one-directional pressure (Figure 4a). During insertion, it is important to remain perpendicular to the joint surface to prevent diverging from the bone tunnel. The implant is advanced into the canal until the inserter makes contact with the bone (Figure 4b). This indicates that the OSSIOfiber^® implant is fully implanted and avoids over-insertion.

Technique Tip: If resistance is felt during insertion, a mallet can be used to gently tap the end of the inserter, to advance the proximal side of the implant into the tunnel.

5. REDUCTION: Reduce the middle phalanx over the remaining distal end of the implant with manual pressure (Figure 5).

Post-Op Protocol

Normal post-op hammertoe protocol is followed. Osseous union will usually occur in roughly 8 weeks. As an isolated procedure, patients can weight bear immediately.

Summary

OSSIOfiber^® Hammertoe Fixation Implant is a new bio-integrative device that provides strong, secure fixation and

bone in-growth, regeneration, and complete replacement. Early results show predictable stability and natural healing in correction of the hammertoe deformity.

1. Albright RH, Waverly BJ, Klein E, et al. Percutaneous Kirschner Wire Versus Commercial Implant for Hammertoe Repair: A Cost-Effectiveness Analysis. J Foot Ankle Surg 2018;57(2):332-38.

OSSIO and OSSIOfiber are trademarks of OSSIO Ltd.

Refer to the product instructions for use for warnings, precautions, indications, contraindications, and complete technique. Medical professionals must use their professional judgment in making any final determinations for product usage and technique.

This case study was created in collaboration with Dr. Chang and Dr. Cicchinelli and was developed from their expertise, training, and professional opinion in addition to their knowledge of the OSSIOfiber Hammertoe Fixation Implant. Patient x-rays are representative of a second patient of similar demographics who underwent an identical surgical approach and has reached the indicated follow up time points. Results from case studies are not predictive of results in other cases. Results may vary.

DOC000749 Rev 02 03/2020