探讨深度塌陷性胫骨平台骨折的形态特点、治疗策略和临床效果。

回顾性分析2016年1月至2020年12月治疗并获得完整随访的30例深度塌陷性胫骨平台骨折患者资料，男16例，女14例；年龄23~59岁。纳入标准为经CT冠状面测量塌陷深度大于15 mm的胫骨平台骨折，排除标准为存在严重疾病、病理性骨折和不能配合的患者。根据胫骨平台Schatzker分型：Ⅱ型15例，Ⅳ型4例，Ⅴ型6例，Ⅵ型5例；三柱理论分型：双柱17例(内侧柱+后柱1例，外侧柱+后柱16例)，三柱(内侧柱+外侧住+后柱)13例；内固定研究学会/创伤骨科协会(AO/OTA)分型为B3型17例，C2型3例，C3型10例。胫骨外髁骨折采用前外侧入路"L"型锁定钢板固定；胫骨内髁骨折采用后内侧入路，于内/前内侧"T"型锁定钢板固定和/或后内侧锁定钢板固定；双髁骨折采用内侧和前外侧入路双侧锁定钢板固定；胫骨平台后外侧象限骨折伴移位者采用倒L入路或Frosch入路支撑固定后外侧壁。术前通过冠状位CT图像测量关节面压缩深度(ADD)，深度塌陷性骨折部位采用自体髂骨或异体骨结构性植骨，同时修复合并的软组织损伤。术后密切随访，通过X片及CT检查评估骨折愈合、复位情况，及术后即刻、术后3、12个月测量胫骨平台内翻角(TPA)和胫骨平台后倾角(PA)，采用重复测量方差分析进行比较，评估骨折复位以及复位丢失情况，按照Rasmussen胫骨平台骨折复位放射学评分评价胫骨平台骨折复位情况。最后一次随访时按照改良美国特种外科医院(HSS)膝关节功能评分进行评价膝关节功能。

所有30例患者均顺利完成手术及获得术后随访，手术时间平均(162±49)min。术后随访时间平均(17±3)个月。所有骨折均获得骨性愈合，骨折愈合时间平均(14.8±1.9)周。术后即刻、术后3月与术后12个月的TPA和PA比较差异无统计学意义(均为P>0.05)。术后12个月Rasmussen胫骨平台骨折复位放射学评分平均(16.7±1.3)分，其中优22例，良8例，优良率100%。术后12个月HSS膝关节功能评分平均(95±4)分，其中优20例，良10例，优良率100%。术后1例患者前外侧切口深部感染，1例患者倒"L"形切口远端皮肤麻木不适，1例患者术后腘静脉血栓形成，总并发症发生率为5.3%。

深度塌陷性胫骨平台骨折多发生于SchatzkerⅡ型以及AO/OTA分型的B3型的骨折，采用单侧入路或者双侧入路，同时进行自体或异体骨结构性植骨，恢复关节面的平整及下肢力线，重建膝关节的稳定性，可获得满意的疗效。

To investigate the morphological characteristics, treatment strategies and clinical effects of deep collapse tibial plateau fractures.

The data of 30 patients with deep collapse tibial plateau fracture treated and followed up from January 2016 to December 2020 were retrospectively analyzed, including 16 males and 14 females; age range was 23 to 59 years. Inclusion criteria: tibial plateau fractures with a collapse depth greater than 15mm measured by CT coronal plane. Exclusion criteria: severe diseases, pathological fractures, and uncooperatives patients. According to the Schatzker classification of tibial plateau, there were 15 cases of type Ⅱ, four cases of type Ⅳ, six cases of type Ⅴ, and five cases of type Ⅵ. According to three-column theory classification, 17 cases were double-column type (one case of medial column+ posterior column, 16 cases of lateral column+ posterior column), 13 cases were three-column type (medial column+ lateralcolumn+ posterior column). There were 17 cases of AO/OTA type B3, three cases of C2 type and 10 cases of C3 type. The fracture of lateral tibial condyle was fixed with " L" shaped locking plate through anterolateral approach; The fracture of the medial tibial condyle was fixed with the " T" type locking plate and/or the posteromedial locking plate through the posteromedial approach. Bicondylar fractures were fixed with bilateral locking plates through medial and anterolateral approaches.The posterolateral quadrant fracture of the tibial plateau with displacement was supported and fixed by the inverted L approach or the Frosch approach. Before operation, the articular compression depth (ADD) was measured by coronal CT image, and the deep collapse fracture site was treated with autogenous iliac bone or allogeneic bone structural bone grafting, while the combined soft tissue injury was repaired. Follow up closely after the operation, evaluate the fracture healing and reduction through X-ray and CT examination, and measure the tibial plateau angle (TPA) and posterior slope angle (PA) immediately, three and 12 months after the operation, using repeated measurement analysis of variance for comparison, evaluate the fracture reduction and reduction loss, and evaluate the tibial plateau fracture reduction according to Rasmussen tibial plateau fracture reduction radiological score. At the last follow-up, the knee function was evaluated according to the modified Hospital for Special Surgery(HSS) knee function score.

All 30 patients successfully completed the operation and received close follow-up after the operation. The operation time was (162±49) min. The follow-up time was (17±3) months. All fractures were bony union. The fracture healing time was (14.8±1.9) weeks. There was no statistical difference between TPA and PA immediately after operation, three and 12 months after operation (all P>0.05). Twelve months after operation, the Rasmussen tibial plateau fracture reduction radiology score was 14 to 18 points, with an average of (16.7±1.3) points, of which 22 cases were excellent, eight cases were good; the excellent and good rate was 100%. HSS knee joint function score was 84 to 98 points at 12 months after operation,, with an average of (95.2±4.1)points, of which 20 cases were excellent and 10 cases were good, and the excellent and good rate was 100%. After operation, one patient had deep infection in the anterolateral incision, one patient had numbness and discomfort in the distal skin of the inverted " L" incision, and one patient had popliteal vein thrombosis after operation, with a total complication rate of 5.3%.

Deeply collapsed tibial plateau fractures often occur in Schatzker Ⅱand AO/OTA type B3 fractures. A unilateral or bilateral approach, combined with structural autograft or allogeneic bone graft, can restore the flatness of the joint surface and lower limb force line, and reconstruct the stability of the knee joint, which can achieve satisfactory results.