1st Metatarsal Phalangeal (MTP) Joint Replacement (Arthroplasty)

Procedure

End (late)-stage hallux rigidus can also be managed with a great toe joint replacement (1st MTP joint replacement).  The goal of this surgery is relieving the patient’s pain while at the same time also retaining any remaining motion present at this joint. When successful, this procedure arguable represents an advantage over the fusion surgery alternative, although one must consider the fact that joint replacement surgery in this area remains an inherently more unpredictable intervention in terms of implant longevity and success.

Many different implants are available for this procedure, and have been designed to specifically resurface the 1st MTP joint on its near side, far side, and/or both sides, depending on surgeon preference and primary disease location in the patient. Regardless of implant choice, it is imperative that the patient discuss with the doctor beforehand all the pros, cons, risks, and benefits of these various surgical options.

Since the arthritic great toe joint (hallux rigidus) is already stiff to begin with and only limited improvement of motion can be expected with implantation of any type of 1st MTP joint replacement, this procedure should be undertaken with caution and only after a complete understanding of the risks and benefits of such intervention has been achieved.

Recovery

Different implants may require different postoperative protocols, which should be discussed. In general, a 6 week period of relative inactivity should be expected, followed by a progressive physical therapy program, weight bearing, and transition to regular shoe wear over the ensuing 1-2 months. Like many foot surgeries, maximum improvement can take upwards of one year post-operatively.

Potential General Complications

Wound healing problems
Wound infection
Local Nerve Injury
Deep Vein Thrombosis (DVT)
Pulmonary Embolism (PE)

Potential Specific Complications

Failure of the joint replacement over time.

This can be a very difficult situation if it occurs. All joint replacements have a tendency to wear and eventually fail over time since they are not made of living material, and the great toe joint replacement (1st MTP replacement) is no exception. In fact, this can be particularly problematic with replacements involving the great toe joint (first MTP joint) as this joint is subject to a significant amount of force with each step. Unfortunately, overt failure of this joint replacement, although unusual, can be catastrophic because it is often associated with a significant loss of bone stock (which leaves a large void or “hole” behind once the implant is removed). This can make salvage options limited and somewhat challenging.

Deep infection of the implant.
Although unusual, infection can involve these implants either early on or sometimes years after implantation. Either situation is very problematic for both doctor and patient, since deep infection more often than not necessitates complete removal of the implant for successful treatment. This too leaves a large void behind, and salvage options are also limited.

Edited July 3rd, 2014