Bunion Correction vs. Total Joint Replacement

Arthritic Bunions: Hallux Limitus vs. Joint Replacement Surgery

Another kind of bunion is called Hallux Limitus (which directly translates to “great toe limitation”).

This condition eventually results in irreversible arthritis of the great toe joint and a stiff joint (Hallux Rigidus).  This problem can be caused by a variety of mechanical problems with the foot, but ultimately results in damage to the joint.  The cartilage that covers our joint is made of hyalin cartilage.  This precious material does not regenerate when it is damaged, so when the joint is worn out, the cartilage is lost forever.

In Hallux Limitus, the erosion of the joint starts because of a mechanical imbalance in the foot resulting in an elevated first metatarsal.  This in-turn results in limitation of the range of motion (ROM) of this joint creating excess wear and tear of the cartilage.  After years of trauma, erosion of the joint surface results in bone on bone contact and pain.  If more than 40% of the surface of the joint has eroded and is void of cartilage, a Total Joint Replacement may be the only procedure that can provide a painless, successful result.

Joint Replacement Implant technology has improved significantly in the past decade, however the fact remains that this is a synthetic joint and is not capable of repairing itself like your own body.  This is why your surgeon will  strive to preserve your own joint if possible.

The Procedure

The procedure has two potential end points:  1. Correction of the problem, with removal of the arthritic edges, and decompression of the joint with an osteotomy technique; or 2. Replacement of the 1st metatarso-phalangeal joint with a synthetic Joint Replacement Implant.

Hallux Limitus corrective surgery is much like bunion surgery. The first step is dissection and exposure of the bony deformity.  This step requires and incision on the medial side of the foot over the MPJ.  This incision is then deepened to the level of the joint capsule.  This is a layer of ligamentous tissue that is thick and covers the entire joint.  The capsule is incised to expose the joint (it will be repaired later).  At this time, the arthritic changes and exostosis (extra bone) are removed .  To definitively correct the problem however, an osteotomy has to be performed to correct the elevated angle of the metatarsal.  The bone is cut and a section of bone may be removed to decompress the joint and provide ROM.

The osteotomy is then fixated with a compressive screw.  The tissues are repaired and the skin is closed.  During the procedure, if your surgeon notices that extra steps are required to provide you with a complete results, he will perform these steps in addition to the basic bunion surgery.  These can include a tendon transfer, sesamoid release, sesamoidectomy, bone or tissue graft, or sub-chondral drilling maybe performed in addition to the basic steps to provide the best result for your particular condition.

If during the time of surgery, with direct visualization, your surgeon appreciates more than 40% cartilaginous erosion, a decision will be made to replace the damaged joint with a synthetic Total Joint Replacement.  This implant will replace the joint surfaces that have been destroyed beyond repair by the arthritic nature of the Hallux Rigidus.  This is done by cutting the joint surfaces out and replacing them with the correct sized Joint Replacement implant. The procedure that will be performed will be decided intra-operatively by your surgeon based on the amount of damage to the joint.

Possible Complications Related to Arthritic Type Bunion Surgery

Hardware Complications
The screws, implants, or other fixation devices used in the surgery may cause discomfort, become loose, or break sometimes requiring removal.    This can also cause dislocation of the osteotomy or fusion site, which can require revision surgery.  There may also be premature breaking or wear of the Joint Replacement Implant. Prudent care of the surgical region during recovery will ensure that dislocation does not happen.  Continued awareness of your new joint will ensure you do not break it.  All synthetic materials wear with time, and although the percentage is low, it may be necessary to consider replacement of the implant in 10-15 years if there is evidence of wear, or sustained damage or dislocation.

Hallux Varus
This complication can be due to contracture of the tissues on the side of the bunion, causing a drifting of the toe in the opposite direction of the original bunion deformity.  It can also be caused by overcorrection, which although an effort is made to avoid, sometimes can happen.  Almost all hallux varus complications can be resolved with either conservative or surgical revision.