Hoffmann II Micro to the Rescue by Jay Lieberman, DPM, FACFAS

Jay Lieberman, DPM, FACFAS, Director of Podiatric Medical Education, Northwest Medical Ctr.

This 53-year-old female is two and a half years status post total joint replacement of the first MPJ of the right foot.  Six months after this first procedure, the patient underwent a standard bunionectomy on the left side.  Upon presentation, her primary concern involved the right foot.  There was considerable pain and limitation of motion in the involved joint.  The toe did not adequately purchase the ground and was significantly shorter than the contra lateral side.  ROM was painful.  She also reported lesser metatarsalgia and chronic stress fractures on the right side.

PAST MEDICAL HISTORY: This includes cardiovascular disease, heart murmur, respiratory ailments, and asthma.

MEDICATIONS: The patient admits to taking Advair, Singulair, Albuterol, Premarin Cymbalta, and Attenolol.          

ALLERGIES: Morphine and Erythromycin

SOCIAL HISTORY: The patient is not a smoker, nor does she consume alcohol.  She does not use recreational drugs.  She drinks very little coffee.  She does drink tea.  Her work obligates her to be on her feet for extended periods.

PAST FOOT/ANKLE HISTORY: There has been a total joint replacement on the right foot in July 2007.

REVIEW OF SYSTEMS: This includes an enlarged aortic valve, recurrent headaches, and asthma.

NEUROVASCULAR EXAMINATION: The patient's neurovascular status is intact.  Pedal pulses are graded +2/+4 bilateral.  Proprioceptive sensoriums are intact.  The skin is supple and well hydrated.  The nails are normal.

LOWER EXTREMITY EXAMINATION: Clinically one notes palpable tenderness in the first MPJ of the right foot and along the weight bearing condyle of the second metatarsal.

X-rays taken on the day of presentation demonstrated evidence of a total joint replacement.  The metallic components appeared to have partially retrograded into the medullary portion of the bone.  The first ray was shorter than the second ray, which was contributing to the metatarsalgia.  There was some overgrowth noted.  Cortical thickening to the second ray was noted.sults.

On clinical inspection, the toe did not clear the ground.  There was some crepitus within the joint.  Hypertrophic scarring was noted.  There were some skin folds crossing medially to laterally along the joint.

ASSESSMENT:

       1. Internal derangement status post total joint replacement first MPJ right

PLAN:

We discussed alternatives during the visit including expectations and possible complications associated with total joint fusion.  I explained to the patient that fusing the joint would help to address the chronic metatarsalgia in the foot.  We would be in a position to lengthen the toe somewhat and the pain intrinsic to the joint would be addressed.  The patient understood that bone grafting might be necessary.  Additionally we considered elongating osteotomies.  The patient was given literature from The American College of Foot Surgeons and asked to view the web site.  We discussed potential complications including infection, bone infection, RSD, aseptic necrosis, and osteotomy displacement along with failure to fuse.

Two months after the initial consultation, the patient was brought to the operating room.  The old two-piece titanium implant was removed.  To maintain length, a tibial bone graft was inserted into the joint space and fixated in place with a metatarsal phalangeal joint plate.  In order to preserve the joint parabola and improve the cosmetic appearance of the foot, a Weil osteotomy was performed on the second metatarsal.  The patient was placed in a below knee cast and maintained non-weight bearing with crutches.  An Exogen bone stimulator was ordered to augment the incorporation of the graft.  

The patient was placed on Augmentin 875mg. one tab po b.i.d.  She was then sent for a CT scan to evaluate the status of the graft incorporation and fusion of the joint. 

The patient returned to the operating room and the plate was removed. The movement of the screw created a defect in the graft and fusion site; however, bony bridging was already evident.

The defect was filled with demineralized bone matrix. The edges of the defects were freshened. Rather than a complete take down of the fusion site, a Hoffmann II Micro external fixation device was applied percutaneously. It was maintained in place for seven weeks. Adjustments were continually made to maintain compression. Once removed the patient was transitioned to an offloading Darco shoe and then back into standard shoe gear.

Although the hallux is a bit shorter than I would have preferred, this represents no more than a cosmetic concern.  The preoperative pain in the joint has abated.  The metatarsalgia is also gone.  In the future, the patient may elect to undergo distal arthroplasties of the second and third toe, more for cosmetic benefit than anything else.

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