Treating Severe Deformity In Young Patients With Rheumatoid Arthritis
A very difficult patient for me to treat is a young patient who has rheumatoid arthritis with severe deformity of the foot and ankle. This is typically a patient whose age may range from the late 20s to late 50s and is active except for his or her foot pain. With this in mind, let’s consider the following case study. A 27-year-old female presented with a 12-year history of rheumatoid arthritis and extreme pain and deformity of the forefoot. While both feet are painful, she says the left foot is more severe than the right. The patient says the pain is in the region of the lateral fourth and fifth metatarsal heads and in the metatarsophalangeal joints (MPJ) of toes two through five. The pain has gotten worse in the past two years and she has trouble with shoes that are not soft and very cushioned. She has tried custom insoles to accommodate the plantar fourth and fifth metatarsal region without much relief. She is currently taking methotrexate and NSAIDs for her pain and rheumatoid arthritis control. What Does The Examination Reveal? An examination of the patient reveals stable and intact neurovascular testing. The forefoot is slightly laterally deviated and there is severe hammertoe deformity of toes two through five of both feet. The main pain is located plantar to the fourth and fifth metatarsal heads with mild pain in the region of a hallux valgus deformity. The contraction of the toes is mildly reducible, yet the main deforming force occurs with dorsal contracture of the extensor tendons and skin on the dorsum of the foot. Attempting to reduce the digits relieves much of the plantar MPJ contraction and deformity yet there is continued plantar prominence of the metatarsal heads, especially on the lateral side of the foot. There is a mild equinus deformity of the ankle with a tight Achilles tendon noted on both the straight and bent knee exam. There is a high arch with midfoot contracture yet this does not seem to be excessive and reduces well with dorsal midfoot pressure and a standing position. The patient’s gait pattern reveals severe extensor substitution with dorsal pull of the extensor tendons at the associated MPJ. Radiographs show mild MPJ dislocation with severe hammertoes and associated hallux valgus deformity of the digits. There is also some osteopenia of the metatarsal heads. Her foot alignment reveals a mild anterior cavus with excellent rearfoot alignment and no signs of degenerative joint disease. What Are The Potential Treatment Options? • Pan metatarsal head resection and hammertoe correction • Hammertoe and bunion correction • Hammertoe, bunion and metatarsal length correction • Hammertoe, bunion and metatarsal correction with extensor tendon transfer • Hammertoe, bunion and metatarsal correction with extensor tendon transfer and skin lengthening at the MPJ • Rearfoot osteotomy and Achilles lengthening in addition to above procedures Diagnostic Answers It is very difficult to correct both the rearfoot and forefoot at the same time when treating patients who have rheumatoid arthritis. This is often too much surgery. In the case of this patient, her rearfoot was stable except for an underlying mild equinus deformity. The main part of the patient consent was for the underlying hallux valgus correction with osteotomy, hammertoe correction of all toes with extensor tendon transfer to the metatarsal heads and a V-Y lengthening of the dorsal skin contracture. The consent also included possible metatarsal osteotomies of metatarsals two through five as needed for correction of the deformity and parabola. We also discussed the possibility of an open Achilles lengthening with the patient. Step-By-Step Pearls We began by making a medial incision to correct the hallux valgus deformity. It is essential to have bone graft on hand for such cases as the osteopenic bone may result in large cystic defects that need grafting. A good option for graft material is the medial eminence or bone from the proximal phalynx distal aspect that is resected with the hammertoe corrections of the lesser toes. In this patient, you would use the medial eminence to fill a small defect in the first metatarsal head following an osteotomy and use two screw fixation to stabilize the osteotomy. V to Y lengthening of the dorsal skin was the second procedure. The procedure was designed to place one V to Y between the second and third metatarsals and one between the fourth and fifth metatarsals.