横 Transfibular アプローチによって総足首置換と足関節変形性関節症の治療

The overall goal of this surgical procedure is to restore proper ankle joint alignment while preserving ankle motion to treat ankle osteoarthritis and to achieve a painless, barefoot gait in arthritic patients. This method can help answer key questions in the foot and ankle orthopedics field about how to treat ankle arthritis and how to preserve joint movement. This technique allows the direct visualization of the center of rotation of the joint, facilitating proper positioning of the implant and minimizing bone resections on both articular surfaces.

Generally, individuals new to this method will struggle with the fibular osteotomy steps, which are key in addressing the fibular lengthening issues that are often present in post-traumatic ankles. Visual demonstration of this method is critical as a successful joint reconstruction requires true understanding of the anatomy and the biomechanics of the ankle. Begin by placing the patient in the supine position with a rigid board under the target leg to sustain the alignment stand.

Position a thick pad under the ipsilateral hip and use a scalpel to make a longitudinal incision over the lateral malleolus that curves under the tip of the malleolus toward the sinus tarsi. Use the scalpel or the periosteal elevator to subperiosteally dissect the fibula and the anterior side of the tibia. When the osteophytes and the joints are completely visible, use a periosteal elevator to release the posterior capsule of the tibia and the fibula.

To make an oblique lateral malleolus osteotomy, use a sagittal saw blade to make an incision beginning from the posterior edge of the fibula six to seven centimeters proximal to the joint line and ending on the anterior side of the fibula two centimeters proximal to the joint line. Rotate the fibular malleolus distally and use a 1.6 millimeter K-wire to fix the malleolus to the calcaneus. Then, use the saw blade and the rongeur to remove the anterior osteophytes until the ankle can be easily placed in a neutral position.

Use the manufacturer's sizer to measure the mediolateral talar width, selecting the largest size possible while avoiding overhang. Place the leg in the alignment stand and internally rotate the foot. Using the four millimeter transtalar pin to fix the talus to the foot plate as distal as possible in the talar neck, facilitating further correction of the talar tilt.

Using a bar parallel to the mechanical tibial axis, check the tibial alignment by fluoroscopy and insert two five millimeter pins into the medial border of the tibia. If an anterior sagittal talar shifting is present, have an assistant push the tibia anteriorly while the pins are inserted. Use the pointer located through the position hole of the cutting guide of the selected size to verify the level of the desired joint line and check the amount of bone resection with the pointer placed in the talus and tibia one holes.

Positioning the joint line is essential for restoring the center of rotation, resurfacing the joint, and preserving the bone. Take care to avoid any sagittal or translational malalignment when performing this key step of the procedure. Insert the four millimeter drill through the pre-cutting guide to pre-drill the talus and the tibia surfaces.

Attach the bone bur to the pneumatic hand pieces. Put the contralateral talar trial of the selected size between the bone bur and the cutting guide to assess the medial depth of the bone cut and use the bur to make definitive bone cuts through the talus and the tibia one holes of the guide. Use the tibia two hole to reach the whole tibial cut on the medial side and to release the osteophytes of the medial gutter.

Position the rail drill guides, utilizing anteroposterior fluoroscopy to verify their proper position, and to avoid lateral overhang. After meticulous preparation of the articular surfaces, position the rail drill guides gently within the joint. If the chaput tubercles interferes laterally, a minimal resection is recommended to avoid lateral overhang of the rail drill guides.

Drill the rails and position the provisional implant. Then select the insert size and use the talar and tibial inserter to introduce the definitive implants. Use fluoroscopy to check the positioning again, using two to three 3.5 millimeter lag screws to fix the fibula.

Apply a bone hook to the lateral malleolus to check the stability of the syndesmosis and gently pull the fibula laterally to assess any residual tibiofibular instability. Stabilize later movement with syndesmosis screw fixation across four cortices as necessary. And test the ankle range of motion.

Then repair the anterior talofibular ligament with resorbable sutures before routine wound closure. In this analysis, 114 patients who underwent total ankle replacement via lateral transfibular approach demonstrated a mean American Orthopedic Foot and Ankle Society hind foot score that improves from 32.2 preoperatively to 85.2 at the latest follow-up. The average physical health composite scale of the Short Form Survey 12 score improved from 30.7 preoperatively to 44.9 postoperatively and the average mental health composite scale of the Short Form Survey 12 score improved from 44.3 preoperatively to 49.9 postoperatively.

The mean Visual Analogue Scale pain score improved from 8.4 preoperatively to 2.1 at the latest follow-up. And all of the differences between the pre and postoperative scores were statistically significant. In this radiograph, a postoperative anterioposterior weight-bearing ankle view of a total ankle replacement implanted through the lateral transfibular approach six months after the surgery could be observed.

An optimal coronal ankle replacement was reached and the fibular osteotomy was fixed by two interfragmentary screws. As observed in this lateral weight-bearing ankle view of the same patient, the bone resections were curved with minimal bone sacrifice, resulting in an economic resurfacing of the bone surfaces. Once mastered, this technique can be completed in 75 minutes if it is preformed properly.

While performing this procedure, it's important to remember to address any ankle malalignment for the attainment of a well balanced implant. Following this procedure, other surgical techniques like supramalleolar osteotomies, hindfoot fusion, or osteotomies can be preformed to address additional ankle joint issues or deformities. After its development, this technique paved the way for surgeons in the field of ankle pathologies to widen the spectrum of therapeutic options for ankle osteoarthritis treatment.

After watching this video, you should have a good understanding of how to perform a total ankle replacement through a lateral transfibural approach. Don't forget that this ankle replacement procedure requires proper surgical training, preferably at one of the major centers for the treatment of ankle arthritis, to further facilitate a better understanding of both the pathology and the treatment of ankle osteoarthritis.