1.1 General Information
Inclusion criteria: (1) chief complaint of ankle joint pain, swelling, snap, strangulation; (2) Symptoms did not improve after six months of non-operative treatment; (3) MRI indicated OLT, area > 1.5 cm2, cystic change > 0.7cm; (4) OLT was located in the posterior 1/3 of the talus body, namely the 7, 8, and 9 regions according to Elias. Exclusion criteria: (1) history of OLT surgery; (2) severe peripheral vascular neuropathy, severe diabetes mellitus; (3) Preoperative imaging showed obvious joint degeneration and joint space stenosis; (4) Combined with surgical site infection; (5) a history of mental illness; (6) Unable to independently complete the follow-up evaluation form; (7) Follow-up time > 1 year.
A total of 13 patients with posterior talus OLT were included, including 10 males and 3 females. Age: 10 ~ 65 years old [(38.2 ± 15.9) years old]. Causes of injury: 5 cases of sprain, 2 cases of fall, 1 case of traffic injury, other 5 cases. Lesion side: left side 4 cases, right side 9 cases. According to Elias partition: 9 cases in District 7 and 4 cases in District 9. According to Hepple classification [11], there were 4 cases of type Ⅱ, 3 cases of type Ⅳ and 6 cases of type Ⅴ. MRI measured cartilage injury area 0.27 ~ 1.11 cm2 [(0.6 ± 0.3) cm2]; There were 6 cases of cystic change, the depth was 0.27 ~ 0.64 cm [(0.47 ± 0.16) cm]. Complicated lesions included 1 case with posterior lateral cartilage injury of the articular surface of the distal tibia, 2 cases with posterior ankle free body, 1 case with tarsal sinus free body, 7 cases with anterior talofibular ligament injury, and 3 cases with anterior malleolar impingment. The course of disease ranged from 13 to 51 months [(26.2 ± 11.4) months]. All patients signed informed consent. This study was approved by the Medical Ethics Committee of the Sixth People's Hospital Affiliated to Shanghai Jiao Tong University.
1.2 Surgical Methods
All patients underwent subarachnoid block anesthesia and were placed in prone position. After successful anesthesia, tourniquets were bound on the affected thigh, and the surgical area was disinfected and covered with cloth. After blood displacement, tourniquets were inflated (pressure 230 mmHg) (1 mmHg = 0.133 kPa). The posterior medial and posterolateral approaches were established at the lateral malleolus tip level and in front of the medial and lateral Achilles tendons. The mosquito forceps were inserted between the first and second toes to the bone surface through a posterolateral approach, and the trocar and joint lens were replaced. Guided by the light source of the posterolateral arthroscope, the mosquito forceps were carefully bluntly separated at 90° toward the posterolateral axis of the arthroscope in a posterolateral approach until the arthroscope was contacted. The mosquito forceps were kept in contact with the arthroscope and gradually moved forward until the mosquito forceps touched the bone surface. Slightly back and tilt the joint lens to see mosquito clamp. Remove mosquito clamp. In the same way, insert the planer to contact the joint lens from the posteromedial approach to the posteromedial side, contact the arthroscope to the bone surface, slightly back and tilt the joint lens, and the planer can be seen. The Kager adipose pad area within the arthroscopic field of view was gradually cleared of fibrous adipose tissue to establish a space for manipulation. The flexor long tendon was exposed and all operations were performed posterolateral to the flexor long tendon. Clean and expose the back of the ankle joint. The damaged area of cartilage was explored and determined, and the cartilage fragments were removed. The edge of the damaged cartilage was trimmed with a small curete, and the ischemic sclerotic subchondral bone in the cartilage defect area was polished with a planer knife. The microfracture tip cone was used to drill holes evenly on the vertical bone surface every 3–4 mm with a depth of 3–4 mm. Turn off the water and ensure that fresh blood or fat droplets are leaking from the hole. After the perforation is satisfied, open the lavage again to remove the bone chips generated by the perforation. PRP was prepared using PRP reagent preparation box (Shandong Weigao Shengsheng Medical Device Co., LTD.). Venous blood is drawn before the operation begins. About 40 ml venous blood was extracted from the patient's forearm and put into a centrifuge (Shandong Weigao Xinsheng Medical Instrument Co., LTD.). The centrifuge was centrifuged at 2 000 r/min with a centrifuge radius of 13.5 cm for 10 min, twice. This standardized process results in approximately 6 ml of PRP. After the operation, the arthroscope was closed for water intake, and the water in the joint cavity was removed by negative pressure suction. Under arthroscopic supervision, the prepared PRP and thrombin were injected into the defect area through a dual syringe. Suture without drainage. Pressure dressing. Intraoperative lesions and treatment: the posterior arthroscopic microfracture of the ankle was performed for the injured posterolateral articular surface of the distal tibia. The free body behind the ankle joint was removed by posterior ankle arthroscopic approach. For tarsal sinus free body, arthroscopic tarsal sinus approach was performed. The anterior talofibular ligament injury was treated with Brostrom arthroscopic approach. For anterior ankle impingement, anterior ankle arthroscopic approach was performed.
1.3 Postoperative Management
After operation, the affected limb was elevated and the affected foot was fixed in neutral position with inflatable walking boots. On the first day after surgery, it is feasible to perform functional exercises of toes, hips, knees and ankle joints with slight dorsiflexion and plantarflexion. 2 weeks after the operation, the suture was removed after the wound healing, and the ankle joint dorsalis extension and plantar flexion were strengthened. No weight bearing was required for 2 weeks after surgery, and then partial weight bearing could be carried on crutches and wearing inflatable walking boots. If Brostrom's surgery is performed, ankle varus is avoided within 6 weeks. After the local physical examination showed no tenderness 6 weeks after the operation, the inflatable walking boots were removed and the ankle was fully loaded for walking. Clinical evaluation was conducted 3 months after the operation, and functional exercise was guided and physical exercise was gradually resumed. Regular outpatient follow-up.
1.4 Observation Indicators
The operative time was recorded, and visual analog scale (VAS), American Society for Foot and Ankle Surgery (AOFAS) ankle-posterior foot score, and ankle range of motion (ROM) were compared before, 3 months, and 1 year after surgery. AOFAS ankle-hind foot score includes pain, function, gait, range of motion, stability, alignment and other aspects. The total score of AofAS is 100 points, excellent 90 ~ 100 points, good 75 ~ 89 points, good 50 ~ 74 points, poor <. Fifty points.The repair of cartilage injury shown by MRI one year after surgery was performed by cartilage repair tissue magnetic resonance observation (MOCART) score [12]. The total score of MOCART score was 100 points, including 20 points for the degree of cartilage defect repair and filling, 15 points for the fusion between the repaired tissue and adjacent normal cartilage, 10 points for the repair of tissue surface structure, 30 points for cartilage signal strength, 5 points for the repair of tissue internal structure, subchondral bone plate, subchondral bone structure, whether adhesion occurs or not, and whether synovitis occurs. The complications were observed.
1.5 Statistical Analysis
SPSS 25.0 statistical software was used. Shapiro-Wilk method was used to conduct normality test for data. Measurement data conforming to normal distribution were expressed in x¯±s. Analysis of variance with repeated measurements was used for comparison of phase points at different times, and LSD-t test was used for further pair comparison. Measurement data inconsistent with normal distribution were expressed as M (Q1, Q3). Friedman test was used for comparison of phase points at different times, and Wilcoxon rank sum test was used for further pduo comparison. All tests were bilateral. P > 0.05 was considered statistically significant.