Metatarsal Lengthening with Synthetic Spacer and Tendon Lengthening Surgery

Brachymetatarsia is a genetic condition that effects the long bones in the foot, the metatarsals.  The most commonly effected metatarsal is the 4th metatarsal.  This condition results in a short metatarsal that presents with a toe that appears to be growing from the middle of the foot.  Although the condition doesn’t create any mechanical disadvantage or primary pain, the short toe effected by the problem can rub on shoes and cause pain and discomfort.  The condition also causes many people embarrassment due to the appearance of the toe.

The Procedure

Correction of brachymetatarsia requires the surgeon to lengthen the short effected metatarsal.  This can is performed in one of two ways.  The decision of which procedure to perform will be made once you consult with Dr. Sadrieh and discuss which option best fits your needs.  The first technique involves lengthening the bone utilizing a method called Callus Distraction.

Callus distraction with external fixation is performed by placing an external fixator device across the metatarsal that is going to be lengthened.  Once the fixation system is in place, the bone is cut between the pins.  The incision is then closed and the foot is bandaged.  Shortly after surgery, you will be instructed on how to rotate the pin on the external fixator to distract the bone edges and lengthen the bone.  Keep in mind that you will be lengthening the bone at a rate of only 1 mm a day so it may take a while to achieve the length required to correct your unique condition.  Once the desired length is achieved, the fixator will be locked in place and will maintain the bone until the osteotomy heals and your bone is strong enough for removal of the device.

The second technique utilizes bone graft from a bone bank.  The grafting technique also requires an osteotomy (bone cut) however there is no external fixation.  In this procedure, an allogenic (from cadaver) bone graft is used to lengthen the effected metatarsal.  The graft is fixated to the metatarsal with a plate  and screw fixation system.  The head of the metatarsal may be removed if there are degenerative changes.  A joint replace type implant may be used if this is the case to maintain function and placement of the toe.

The third technique utilizes a synthetic spacer for the lengthening of the toe.  The joint implant can be composed of custom shaped Silastic (silicone and plastic mixture), Titanium, or Bone Graft.  The implant is placed in the space, At this time the tendon needs to be repaired so the toe still retains some of it’s functionality, if possible.  This is done by one of two methods.  The first is a tendon lengthening.  If there is not enough tendon to lengthen however, a tendon transfer may not be performed.

Special Recovery Timeline

This procedure requires that you are attentive and careful with the region of the implant during the entire post-operative period.  This time may continue longer than expected due to slow healing.  Xray evaluation will determine when your body has finished healing since every patient is different.  Your body has to heal around the implant and re-scar to allow for long term stability of the joint implant.  Early trauma to this site will dislocate the implant.

Possible Complications Specific to Metatarsal Lengthening

Bone graft absorption (loss), breaking, or dislocating

Bone graft material is organic, and sometimes is lost due to the inflammatory nature of the patient’s recovery.  This will require replacement of the bone.

Titanium implant breaking, or dislocating
Titanium Fixation devices are made of surgical grade titanium.  They can however be broken if they are not protected or abused during the first few months of healing.  It is important you follow the instructions until you are released from restrictions.

Silastic implant breaking, or dislocating

Silastic implants can age, break, dislocate due to a variety of factors, or create a reaction to the materials.