This retrospective study reviewed 32 consecutive patients who underwent surgical treatment for Takakura-Tanaka stage 3 post-traumatic ankle arthritis after failure of conservative treatment from January 2015 to December 2018.
Ankle distraction arthroplasty was used in 13 patients (seven men, six women; average age 54.7 ± 12.8 years; five left ankles, eight right ankles; eight patients with a clear history of ankle trauma, five with unknown etiology). Nineteen patients were treated with supramalleolar osteotomy (nine men, 10 women; average age 59.4 ± 7 years; eight left ankles, 11 right ankles; 13 patients with a definite history of ankle trauma). The institutional review board approved the study, and all patients provided informed consent for study inclusion.
Inclusion criteria
Age > 18 years; ankle pain and swelling for > 3 months and failure of conservative treatment; Takakura-Tanaka stage 3 ankle arthritis; no other surgical treatment around the ankle; complete pre- and postoperative data and imaging examinations; good physical function and ability to tolerate surgery; provision of written consent and postoperative follow-up for at least 12 months.
Exclusion criteria
End-stage ankle arthritis; infection around the ankle; history of ankle fracture; other serious deformities or diseases of the foot and ankle, such as clubfoot or diabetic foot; incomplete pre- and postoperative case data and imaging examinations; follow-up duration < 1 year; serious medical or neuromuscular disease; mental illness that prevented cooperation with follow-up evaluation.
Contraindications
Congenital collagen deficiency; bodyweight > 120 kg; severe heart disease; lesions affecting liver and kidney function; severe diabetes; central nervous system diseases; other medical diseases.
Preoperative examination
Preoperative evaluation of all patients included a detailed history, physical examination, and imaging examination, including the ankle anteroposterior position, measurement of the tibial anterior surface angle (TAS), talar tilt angle (TT), tibial lateral surface angle (TLS), calcaneal axial X-ray to assess the force line of the lower limb, and assessment of the presence of varus or valgus of the calcaneus and talus. CT was performed to evaluate the condition of the subtalar and tibiotalar joints; MRI was performed to evaluate the cartilage condition of the ankle, presence or absence of talar necrosis, condition of the surrounding soft tissue, presence or absence of edema of the surrounding ligaments, and completeness of the lateral ligaments.
Operation procedures
The supramalleolar osteotomy group received prophylactic intravenous antibiotics 30 minutes preoperatively. After anesthetic induction, the patient was placed in supine position. A tourniquet was placed at the proximal extremity, which was routinely disinfected and draped with a sterile surgical towel. A 4-cm longitudinal incision was made in the middle of the anterior ankle to expose the ankle joint cavity and assess whether there was contact between the ankle and tibial joint surfaces. Intraoperatively, there was lip-like hyperplasia of the tibial joint surface, hyperplasia of the lateral talar surface, and limited passive movement of the ankle. The proliferative bone was removed, and the ankle was moved passively until the range of motion was close to normal. The joint cavity was washed with normal saline and the surgical incision was sutured. A Kirschner wire was used as an osteotomy guide 4–5 cm above the ankle joint. After the osteotomy direction was confirmed on X-ray fluoroscopy, the medial, anterior, and posterior cortices were cut from the anterolateral side parallel to the articular surface of the distal tibia, and the contralateral cortices and periosteum were retained to form a hinge when the osteotomy was opened and were inserted into the wedge-shaped bone block to increase the stability. After satisfactory correction of the varus deformity, a Kirschner wire was used for temporary fixation. Autogenous or allogeneic bone was implanted at the osteotomy site. An anatomical steel plate was used to fix the osteotomy end. The incision was closed.
The ankle distraction arthroplasty group underwent the same ankle debridement procedure as the supramalleolar osteotomy group. The ankle joint was placed in a neutral position and the annular external fixator was placed in a suitable position with the extension rod directly opposite the ankle joint activity center. A 2.0-mm-diameter Kirschner wire was used to drill 8 cm below the knee joint, and then two Kirschner wires were drilled 5 cm above the ankle joint and parallel to the knee joint; one Kirschner wire was fixed in front of the calcaneal tubercle, and one was fixed in the metatarsal base of the anterior foot. Each ring was reinforced with a threaded needle.
Postoperative management
The incision was routinely dressed and antibiotics were administered. To promote functional recovery of the ankle and prevent postoperative stiffness, both groups began early postoperative rehabilitation exercises. The Kirschner wire hole was wiped with iodophor every day to prevent sinus tract infection. From postoperative day 1, patients were instructed to exercise the toes and quadriceps femoris to prevent deep venous thrombosis. At 1 week postoperatively, the ankle was photographed from the anteroposterior and lateral aspects. In the ankle distraction arthroplasty group, the external fixator was adjusted as needed; the ankle joint cavity was gradually stretched by about 0.5 mm every day and adjusted every 12 hours until the ankle joint space was pulled out by 5 mm (the external fixator was adjusted at any time based on the patient's condition). The ankle was half loaded by 1 month postoperatively, and completely loaded by 2 months postoperatively. At 3 months postoperatively, the external fixator was removed and ankle rehabilitation training was commenced. The supramalleolar osteotomy group performed the same functional exercises to prevent postoperative ankle stiffness and enhance the joint range of motion.
Efficacy evaluation
All patients were assessed by independent allied health staff preoperatively and at 6 and 24 months postoperatively. Patient demographic data, including age, sex, and BMI, were collected preoperatively. Patients were asked to rate their overall satisfaction with their surgical results as ‘excellent’, ‘good’, ‘fair’, or ‘poor’.(Table 1)
Table 1
Clinical Rating Scale for Postoperative Ankle.
Rating
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Description
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Excellent
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Full range of motion equal to the contralateral ankle without pain. Un-restricted work or sports activity.
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Good
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Functional range of motion and stable ankle. Able to return to the previous level with minimal pain with work or sport activity
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Fair
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Functional range of motion, good stability, moderate level of pain, and/or stiffness with activities of daily living and sports activity.
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Poor
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Persistent instability or pain, the same or worse than before surgery.
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All patients were followed up for at least 12 months, and routine radiological examination comprised anteroposterior and lateral radiographs of the ankle, and full-length lower extremity weight-bearing radiographs. A goniometer was used to obtain the ankle angle measurements (TAS, TT, and TLS) and compare them with preoperatively.
The range of motion of the affected foot and the healthy foot was measured, including the ranges of varus, valgus, dorsiflexion, and plantarflexion.
The American Orthopedic Foot & Ankle Society (AOFAS) ankle-hindfoot score was used to objectively evaluate the pain severity, function, gait, and force line of the affected ankle as excellent (90–100 points), good (75–89 points), fair (50–74 points), or poor (0–50 points). Visual analog scales (VAS) pain scores were also recorded.
To reduce errors and ensure the accuracy of data, all measurements were conducted by three doctors at the same time, and the average of the three results was used in the analysis.