Pertinent Insights On Total Joint Replacement Of The First MPJ

Eric Lullove, DPM

   Three weightbearing radiographs of the right foot demonstrated joint space narrowing of the first MPJ with sclerosis and marginal erosions to the distal phalanx of the right hallux. There was gross osseous deformity of the distal first metatarsal bone with severe joint impingement. There was a lack of range of motion in repeated attempts to force the joint into stress dorsiflexion. There were traumatic signs of arthrosis to the first MPJ. X-rays revealed evidence of severe arthropathy to the medial first MPJ.

   My diagnosis was stage IV hallux rigidus of the right foot.

A Guide To Planning And Performing MPJ Replacement

At the time of the first visit, I gauged the preliminary treatment to reduce his pain. I injected 1.5 cc of 1% xylocaine, 0.5% bupivacaine and 0.5 cc of methylprednisolone-40 under ultrasound guidance to the first MPJ of the right foot. The patient received adequate counseling regarding conservative versus surgical treatment for his complaint. The patient noted that his previous physician had already given him at least four injections over the last year to combat the pain. At this point, he wanted to discuss surgical outcomes and treatments.

   I thoroughly discussed the planned surgery with the patient. We agreed on a total joint replacement of the first MPJ. This would provide the patient with the best long-term result without undergoing full arthrodesis/fusion, which the patient did not want. I discussed all risks, benefits, alternatives and complications with the patient in complete detail prior to surgery and prior to obtaining surgical consent.

   I made a 6 mm linear incision to the dorsal aspect of the first MPJ, extending it from the hallux to the midshaft of the first metatarsal, dissecting carefully to avoid neurovascular structures. I performed an inverted-T periosteal incision, reflecting all capsular and periosteal surfaces. A thorough examination identified the amount of arthritic bone that had to be removed from the joint and where the osteotomies were to occur.

   Using a sagittal saw, I resected redundant arthritic bone from the hallux and first metatarsal head. The amount of bone was consistent with the preoperative diagnosis of stage IV hallux ridigus. The bone removed showed severe arthrosis and sclerosis upon resection.

   I resected the remainder of cartilaginous surfaces of the joint according to the surgical plan to replace the first MPJ, using the ReFlexion Total Joint Implant (Osteomed). I used Osteovation Bone Void Filler (Osteomed) to fill in gapping between the implant surface and the resected bone surface of both the hallux and first metatarsal. Intraoperative fluoroscopy confirmed implant placement. I loaded the first ray and put the joint through an aggressive range of motion that showed dorsiflexion of 55 to 60 degrees.

   Upon complete replacement of the joint, I irrigated the site with NSS-bacitracin, and re-approximated redundant capsular structures with 2-0 vicryl. Subcutaneous closure occurred with 3-0 vicryl and skin closure occurred with 3-0 Ethilon (Ethicon) in a horizontal mattress technique.

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