This was a retrospective study. The study protocol was approved by the institutional review board of the Third Hospital of Hebei Medical University and all patients provided the written informed consent.
The inclusion criteria were age >18 years; chronic pain and swelling of the medial malleolus for >3 months and failure of conservative treatment; Hepple V medial talar cartilage lesion on MRI; no prior talar surgery; good physical condition and ability to tolerate surgery; provision of written consent for postoperative follow-up.
The exclusion criteria were the cartilage injury in other locations, such as the lateral or central part of the talus; severe ankle arthritis; active infection of the ankle; history of talar fracture; other serious deformities or diseases of the foot and ankle, such as clubfoot or diabetic foot; inability to tolerate surgery due to serious disease; unwillingness to cooperate with postoperative treatment or follow-up.
The above criteria identified 32 consecutive patients who underwent iliac bone grafting for treatment of medial OLT with subchondral cysts after failure of conservative treatment from January 2015 to January 2020. The cohort comprised 19 men and 13 women (mean age, 35.8 years; range, 25–59 years), with 17 left-sided injuries and 15 right-sided injuries. All patients had posteromedial cartilage injury, including seven patients engaged in sports activities, five workers who were required to stand for prolonged periods of time, 11 manual workers, eight patients with a sedentary lifestyle that lacked physical activity, and two with other conditions. All patients underwent preoperative MRI and CT examination of the ankle, including measurements of the diameter and area of the cystic lesion. According tothe American Orthopaedic Foot & Ankle Society (AOFAS) and the Visual Analogue Scale (VAS), the ankle joint function and the severity of ankle joint pain were evaluated and recorded in all patients.
Surgical procedure
All surgeries were performed under lumbar anesthesia with the patient in supine position and a sterile pneumatic tourniquet applied on the proximal thigh of the affected limb. The skin was routinely disinfected with iodine and alcohol and draped with a sterile surgical sheet before a 5-cm-long curved incision was made on the anteromedial side of the affected ankle. Two 3 mm diameter Kirschner wires were used to enter the tibia at a 45 ° angle, and about 2cm above the tip of the medial malleolusone, one 2.5 mm Kirschner wire was used to enter the tibia and remained vertical to the previous Kirschner wire. X-ray fluoroscopy showed that the position was satisfactory. The swing saw was used to cut off the medial tibia along the direction of 2.5mm Kirschner wire, the valgus ankle joint fully exposed the cartilage damage area on the medial side of talus fornix, and the cartilage scraper was used to remove the degraded cartilage. After assessing the size of the lesion, a bone extractor with a suitable diameter was selected to punch a vertical hole in the joint surface and remove the lesion and cyst. Kirschner wire was used to make microfractures in the sclerotic bone around the cystic cavity, and take uniform blood infiltration as the standard. The incision of the anterior superior iliac spine on the same side is about 2.5cm long. The bone extractor is used to remove the iliac composite bone column. When taking out the bone, pay attention to avoid damaging the inner and outer walls of the iliac bone. After trimming the damaged area to an appropriate size, plant it on the damaged part of the talus cartilage, and trim the filling area to ensure that the graft is flush with the surrounding joints. During the reduction of the medial malleolus osteotomy block, follow the bone guide tunnel reserved before the 3.0mm Kirschner wire, use the 4.0mm hollow drill to expand the bone tunnel, use the half thread hollow lag screw to pass through the Kirschner wire to fix the osteotomy site, remove the Kirschner wire, and conduct X-ray fluoroscopy to confirm that the reduction of the osteotomy site is satisfactory, the bone cartilage graft in the graft area is fully filled, the joint surface is restored to be flat, and the incision is closed layer by layer.
Postoperative rehabilitation
Postoperative, all patients used the same rehabilitation training method and was given plaster external fixation of lower limbs for 45 days; on postoperative day 2, patients began isometric muscle contraction and interphalangeal joint flexion and extension activities on their own. After 2weeks, after suture removal, patients began plantar flexion, dorsiflexion, inversion, and valgus activities of the ankle. After one month, patients began partially weight-bearing with crutches. After 6 weeks, remove the plaster and gradually increase the load to full load, but prohibit vigorous activities. After three months, patients were permitted to walk with full weight-bearing and gradually return to normal life.
Outcome Measures
All patients were assessed by independent investigator preoperatively and at 3 and 24 months postoperatively. Routine radiological examination comprised anteroposterior and lateral radiographs or CT of the ankle. To observe the bone healing at the osteotomy of medial malleolus and the bone healing of grafts in the injured area of talus cartilage. Due to the existence of metal internal fixation in the patient's ankle, the patient did not undergo MRI after operation. At the last follow-up, the AOFAS ankle hindfoot score and the VAS score were used to evaluate the patient’s ankle joint function and pain. At the same time, the patient’s iliac bone extraction site was monitored for surgical incision healing, whether there was pain, and whether there were other possible complications. To reduce errors and ensure the accuracy of data, all measurements were independently performed by three investigators, and the average of the three results for any measurement was used in the analysis.