A novel arthroscopically assisted reduction technique for three patterns of posterolateral tibial plateau fractures

Abstract

Background: Posterolateral tibial plateau fractures (PTPF) remain a challenge for orthopedics surgeons because the special anatomical structures of the posterolateral corner of knee joint including the fibular head, the lateral collateral ligament, and the peroneal nerve, which impedes the exposure of the fracture fragments and need irregular implants to get a stable fixation. The purpose of present study was to introduce a new articular fracture fragments restoration technique for three patterns of PTPF and investigate the relationship between associated soft injuries and fracture patterns.

Methods: From May 2016 to April 2018, 31 patients with PTPF who had undertaken arthroscopically assisted reduction and fixation (AARF) were enrolled in present study. Demographic data, pre-operation, and post-operation X plan films, three-dimensional computed tomography (CT) scans and magnetic resonance imaging (MRI) were reviewed. Present samples were divided into three patterns with lateral inclination (LI), posterior inclination (PI), and parallel compression (PC) according to the orientation of the articular fragment inclination. Rasmussen anatomical score was used to assess the radiological results. Rasmussen functional score, Hospital for Special Surgery knee-rating Score (HSS), and range of motion (ROM) of the knee joint at the final follow-up were measured to evaluate the clinical outcomes.

Results: In this series, the post-operation tibial plateau angle (TPA) was 9.7° ± 3.5°(range 4.0°-15.8°) and the Rasmussen anatomical score was 17.7 ± 0.7(range 16-18); clinical outcomes showed that the HSS score was 92.7 ± 21.8 (range 90-96) and the Rasmussen functional score was 27.9 ± 1.0 (range 26-30). Of all the patients, the anterior cruciate ligament (ACL) injuries including the ACL tibial attachment ruptures occurred in 16 patients (51.6%), meniscus lesions happened in 19 patients (61.3%), medial collateral ligament (MCL) injuries were founded in 13 patients (41.9%). The number of ACL injuries including the ACL tibial attachment ruptures in the PI fracture pattern (12 cases) is significantly higher than LI (2 cases) and PC (2 cases) fracture pattern (p < 0.05).

Conclusion: Profound understanding the different patterns of PTPF and using our reduction technique will facilitate to restore the main articular fracture fragments. The PI fracture patterns have a significant high incidence of the ACL ruptures.

Level of evidence: Therapeutic study, Level IV.

Keywords: Arthroscopically assisted reduction and fixation; Fracture patterns; Posterolateral tibial plateau fracture; Restoration; Soft tissue injury.

Fig. 1

The measurement of TPA. L1 is parallel to the anterior crest of tibial; L2 is the perpendicular line of L1; L3 is the tangent line of the tibial plateau. Angle α represents the TPA

Fig. 2

The three patterns of posterolateral tibial plateau fracture. The broken lines represent the inclination orientation of the main articular surface fracture fragments. PI, posterior inclination; LI, lateral inclination; PC, parallel compression. The yellow bar shows where the metal tamp placed

Fig. 3

A 44-year-old male patient who was diagnosed with the lateral inclination type of posterolateral tibial plateau fracture with LI patterns. a The coronal image of three-dimensional CT scans shows the lateral inclination of the tibial fracture fragment. b The anteroposterior (AP) plain film of the injured knee. c The lateral plain film of the injured knee. d The tibial plateau fracture visualized with the assistance of arthroscopy. e After restoration of the fracture fragments with the surveillance of arthroscopy, the step-off was eliminated. f The coronal image of three-dimensional CT scans shows the restoration and the fixation. g The post-operation AP film of; H, the post-operation lateral plain film