Looking For New Ways to Stabilize Foot Deformities in Diabetes Patients
Managing blood sugar levels isn't the only problem facing patients with diabetes. Over time, complications such as collapse of the arch in the foot can occur. This condition is called Charcot midfoot arthropathy. Charcot is the name of the physician who first discussed this problem.
Ulceration, fracture, dislocation, and deformity associated with the Charcot foot can be serious problems to deal with. There isn't an easy answer to treatment. In this study, surgeons from the Cincinnati Sports Medicine and Orthopaedic Center try an alternative surgical approach. They used several metal screws through the bones of the foot to line everything up and hold it in place.
Their technique was to use screws long enough to thread them through the fragmented areas. The screws were placed through normal, healthy bone on either side of the damaged area. This particular treatment method is used for patients with severe deformity and loss of independence in walking. Most have poor bone quality and loss of normal blood supply to the foot. Delayed tissue healing is typical because of the diabetes.
The goal of this surgery is to fuse the midfoot in order to give the patient a stable foot to walk on -- one that doesn't break down and form ulcers. They hoped that by spanning a wider area of bone, they could correct the severe foot deformity and keep that correction. The type of screws used allowed for tightening of the hardware across the fusion site. This technique makes it possible to create a compressive, holding force.
The study involved 22 patients with severe midfoot deformity from Charcot disease. Surgical reconstruction for the midfoot collapse was done as described. Patients were classified according to the Sammarco and Conti system. This system involves four basic patterns of foot deformity.
The classifications depend on the location and amount of destruction across the midfoot. Drawings and X-ray examples are provided to help the reader understand the different patterns of joint separation and deformity. Changes in bone angles and places of dislocation were viewed and described.
All of the patients had a terribly swollen and red foot with obvious deformity. The feet were unstable. Conservative care had not worked. Bracing was no longer an option. Some of the patients had ulcers on the bottom of the foot where the misaligned bones rubbed during weight-bearing and walking. The ulcers had to be treated first before surgery to correct the foot deformity could be done.
Successful treatment of the ulcers can be a challenge in itself. Many of the patients had multiple comorbidities (other health problems) as well. High blood pressure, low thyroid, heart disease, and a history of cancer or stroke were common. Each patient was under the care of a primary care physician or internist for these medical comorbidities.
The authors provide a detailed description of the patients position during the procedure, type of anesthesia used, and surgical technique performed. Fusion of the midfoot was only one part of the total reconstruction process. In addition to the placement of the screws, most of the patients required the release of tight or contracted soft tissues to restore ankle motion.
Fluoroscopy, a special kind of X-ray, was used in the operating room to make sure the bones were placed correctly and in the best alignment possible. There were many challenges facing the surgeons. For example, the tension on the bones and soft tissues had to be just right to avoid loss of blood supply to the area.
Sometimes the bones weren't just dislocated, they were broken into tiny little pieces. In some cases, the damaged or dead bone had to be removed. Places of dense scar tissue had to be cut out. Some of the methods used to realign the bones in the earlier cases in this series didn't work. The surgeons gradually perfected their technique over time. They found better ways to accomplish the fusion that didn't result in bone or screw fracture.
Postoperative care was as important as the surgery. The patients worked with a physical therapist while in the hospital during the early days after the procedure. Serial (weekly) casting was done during the first stage of healing. Casting was used to help hold the foot alignment and prevent weight-bearing, sometimes for as long as seven months.
Patients progressed from a cast to a removable pneumatic walking boot. Full weight-bearing was allowed when X-rays showed a stable fusion (no movement in the fused joints) with hardware still in place. Eventually, a special shoe insert called an orthotic was designed for each patient. X-rays were retaken from time to time to measure foot angles and deformity while also making sure everything was still holding stable.
There were some individual complications such as nonunion, failure of the hardware (migration or movement, breakage), bone fracture, collapse of the foot arch, infection, and recurrence of foot ulcers. Many of the patients required more than one surgery to accomplish the final reconstruction. Healing took a long time (many months). But in the end, the results allowed the patients to regain independent walking.
The authors conclude that their surgical technique can be used to stabilize severe Charcot foot deformities. The rates of success (measured by deformity correction and maintenance and fusion rates) were equal to results from other studies using other techniques. The foot can be saved with this technique. It has the advantage of not being as invasive as other approaches and that's important for this particular patient population because of the negative effects of diabetes on healing tissue.
V. James Sammarco, MD, et al. Midtarsal Arthrodesis in the Treatment of Charcot Midfoot Arthropathy. In The Journal of Bone & Joint Surgery. January 2009. Vol. 91A. No. 1. Pp. 80-91.