Inclusion and exclusion criteria
Inclusion criteria: ① Schatzker type II fresh closed tibial plateau fracture involving posterolateral column within two weeks after injury; ② sagittal width of the involved posterolateral tibial plateau articular surface > 1.5cm; ③ no injury of nerves, blood vessels,no severe injury of head, chest, abdomen, nor other critical functional organs; ④ the affected knee joint can walk normally before the injury, without apparent osteoarthritis and trauma history. Exclusion criteria: ① open tibial plateau fracture; ② accompanying neurovascular injury; ③ multiple fractures of lower limbs, influencing rehabilitation; ④ no rehabilitation treatment after operation; ⑤ unable to follow up on schedule or follow-up time < 1 year.
According to the inclusion and exclusion criteria, the data of 23 patients with tibial plateau type II fracture involving the posterior column from January 2014 to January 2018 were collected, including 16 males and 7 females, aged 26-69 years.
All cases were Schatzker type II. According to the three-column classification of Luo (14), the posterolateral column of the tibial plateau was involved.
(1) Preoperative planning
The affected limb was fixed with plaster or calcaneal traction. Before the operation, routinely X-ray, CT scan, and 3D reconstruction were performed, while MR examination taken if necessary, and operation was performed after ‘wrinkle sign’appeared.
(2) Surgical technique
The extended anterolateral approach group（Group A）(12): First, the limb was slightly flexed. An approximately 15- cm-long S-shaped incision with Gerdy’s tubercle as the center was made to expose iliotibial band and anterolateral calf fascia. The iliotibial band was split in the middle along the direction of the fibers and sharply elevated from Gerdy’s tubercle anteriorly and posteriorly. The fascia incision was extended downward, and about 5 mm fascia flap was left for further repair. The dissection was extended posteriorly by taking down the extensor muscles from the lateral surface of the lateral plateau to the point in front of the fibular collateral ligament (FCL). Then, the knee joint was flexed up to 90° to relax the fibular collateral ligament and the common peroneal nerve. Then, with the FCL retracted posterolaterally, the posterolateral surface of the lateral plateau was exposed by dissecting loose soft tissues between them. Last, we opened the joint capsule and retracted the lateral meniscus superiorly to expose the joint surface. After that, we reduced the fragments and used Kirschner wires for temporary fixation. The lateral locking plate (Synthes GMBH, Zuchwil, Switzerland) was placed as posteriorly as possible, and the transverse arm stretched to the supra-fibular-head space. In an excellent situation, two rafting screws supported the articular surface of the posterolateral column.
Frosch approach group（Group B） (13): First proposed Frosch, a single lateral incision without fibula head osteotomy was used to treat the anterolateral and posterolateral plateau fractures at the same time. The treatment of anterolateral platform fracture is the same as the previous anterolateral approach. However, at the same time, it enters the exposed posterolateral platform between the lateral head of gastrocnemius muscle and soleus muscle, to achieve an incision treatment of tibial platform fracture involving both the lateral column and the posterolateral column.
Compared to the original Frosch approach, a little modification was made in this practice. The anterolateral fracture was treated in the interval of the anterior tibial muscle. The fibula starting point of the soleus muscle was sharply dissected downward along the fibula, and it was pulled to the posteromedial together with the lateral head of the gastrocnemius muscle to reveal the posterolateral fragments instead of through the interval between the lateral head of the gastrocnemius muscle and the soleus muscle. However, there was no essential difference from the Frosch approach.
Postoperative drainage routinely continued for 48h, and also the antibiotic use. Low molecular weight heparin was used to prevent deep venous thrombosis of the lower limbs, according to the Caprini Score. Early ROM and non-weight bearing movements were emphasized. Passive joint function activity was performed immediately after the operation, and continuous passive motion exercises were initiated on the second day postoperatively. Three days later, the patients were encouraged to participate in active motion rehabilitation without weight-bearing under the guidance and supervision of the surgeons. Partial weight-bearing was allowed after the second postoperative week(12), but not the loaded squat. The time to full weight-bearing depended on the radiographic evidence of fracture healing and callus formation.
Data collection and follow-ups
General information of patients was collected before the operation, as well as medical complications.
The operation time, blood loss, fracture healing time, fracture reduction, the American Hospital For Special Surgery (HSS) score(15), knee range motion, tibial plateau angle(TPA), posterior slope angle(PSA) and postoperative complications were noted. According to the standard clinical and radiological criteria to judge the healing time of the fracture, the Rasmussen score(16) system was used to evaluate knee joint function in the 12th month. Patients were followed-up every month until The radiographic evidence showed fracture healing and callus formation. Then patients were followed-up every three months for at least 12 months in total.
The operation time, blood loss, fracture healing time, knee HSS and Rasmussen score, and range motion, and other quantitative data were compared between group A and group B by the independent t-test, while categorical data compared by the chi-square test (Fisher’s exact test). P < 0.05 was considered statistical significant. Graphpad prism 8.02 (GraphPad Software Inc. San Diego) was adopted to record and analyze the study results.