You can resect additional bone later when using the reamer to remodel the contour of the base to match the implant after broaching the canal. I find that using a 2.7-mm drill instead of the pointed broach helps create a pilot hole in the center of the bone since the sclerotic base is difficult to penetrate. The triangular shape of the stemmed broach enables you to correctly orient the right and left side appropriate implant. Bear in mind that you will need to use a mallet to seat the device. While the 2.7-mm drill requires less force in driving the broach into place in a sclerotic base, you still need to have resistance and a firm grip on the great toe in order to prevent excessive tension on the capsule structures. At this point, you can place the trial implant with the impactor and subsequently reevaluate the patient’s range of motion. If you find the implant to be tight in the joint space, you can resect additional bone with a sagittal saw or the shallow reamer. You must follow this with the stem broach in order to facilitate full seating of the implant. Now you can place the LPT Hemi-Toe Implant. The implant will have one perforated hole at the dorsal surface and one at the plantar surface. This allows for right and left great toe placement where the flexor tendon can be reinforced or reattached at your preference. I have found that this is not a common part of the procedure I perform, given the low profile size of the implant. I also prefer not to handle the implant any more than necessary in order to minimize intraoperative complications or the occasional mistake that requires a new implant. What You Should Consider In The Post-Op Evaluation Proceed to close the soft tissue and reevaluate the patient’s range of motion and joint stiffness along with his or her skin. Occasionally, I may evaluate the trial implant with capsule closure to ensure appropriate range of motion prior to implanting the permanent implant. Pre-op and post-op implant placement should demonstrate corrected hallux position and preserved toe length. As in any procedure, there may be potential complications. These include: • a lack of hallux purchase; • fracture of the metatarsal head or base of the proximal phalanx; • loosening of the prosthesis; • osteolysis or osteoproliferation around the implant system; • blockage of the hallucal sesamoid position; • unmasking of preexisting sesamoid pathology; • recurrence of the deformity; and • painful/limited MTPJ range of motion. Final Words Although silastic implant arthroplasty has been performed for nearly 40 years, the metallic implant devices present a new era for use in the arthritic joint. Appropriate patient selection is essential and the procedure can be successful when the first metatarsal head has a restorable contour and a corrected intermetatarsal angle with no unaddressed biomechanical abnormalities. The thinner anatomic articulate design of the implant allows for a smaller resection of the proximal phalanx base and preserves the flexor hallucis brevis tendon. Dr. Cusumano is a Fellow of the American College of Foot and Ankle Surgeons. He currently practices in Englewood, Fairlawn and Riverdale, N.J., and serves as a team physician/podiatrist for the athletic teams at Fairleigh Dickinson and Montclair State Universities. Editor’s Note: For a related article, see “Titanium Hemi-Implant: A Vital New Solution For MTPJ Pain?” in the January 2001 issue of Podiatry Today or check out the archives at www.podiatrytoday.com.
References 1. Marcinko DE: Medical and Surgical Therapeutics of the Foot and Ankle, pp 423-465, Williams & Wilkins, Baltimore, 1992. 2. Gerbert J, Chang T: Clinical Experience with Two-Component First metatarsal Phalangeal Joint Implants. Implantable Biomaterials 12(3)403-413, 1995.