Anatomical Research And Clinical Application Of Inverted L-shaped Approach In Posterior Aspect Of Knee Joint

Objective :1 Based on the anatomical research and clinical application, this study was carried out to analyze and explore how to avoid the secondary damage of nerves, blood vessels and other important structures, and clarify the exposure step, safe area and dangerous zone in the surgical treatment of posterior column fracture in tibial plateau by inverted L-shaped approach in the posterior aspect of knee joint. It was hoped that some guidance on the correct use of this approach was offered, the curative effects of surgical treatment of complex tibial plateau fractures were improved.2 the clinical effects of this approach were determined after its application in clinical practice. Methods:1.After 32 formalin-fixed lower limbs of 16 adults for teaching were chosen from the teaching and research section of Chengde Medical University, how important nerves, blood vessels, muscles and ligaments related to the inverted L-shaped approach in the posterior aspect of knee joint ran and were distributed were observed after the dissection, and the anterior tibial artery, and the anterior tibial artery that could be easily injured in the approach, and the nerve innervating the medial gastrocnemius muscle were observed and measured. All of the data were presented by( x ±s) mm. SPSS17.0 statistical software was used. An independent sample t-test was carried out. P<0.05 indicated that the difference was statistically significant.2 Based on the anatomical research, the inverted L-shaped approach in posterior aspect of knee joint was adopted in the surgeries of 5 patients with posterior column fracture in tibial plateau hospitalized from September 2013 to February 2014. After the Rasmussen scoring system was used to evaluate the fracture reductions right after the surgery, and the results in the last follow-up were scored using HSS(The Hospital For Special Surgery) knee-rating scale, the curative effects of the approach were observed. Right and 12 months after the surgeries, standard full-length antero-posterior X-ray images of the lower limbs were taken, and the TPA(Tibial Plateau Varus Angle) and the FTA(Femoral Tibial Angle) were measured. All of the data were presented by( x ±s)°. SPSS17.0 statistical software was used. A paired samples t-test was carried out. P<0.05 indicated that the difference was statistically significant. Result:1. Anatomical measurement results: the inverted L-shaped approach in the posterior aspect of knee joint entailed no exposure of the tibial nerve and popliteal artery and vein; exposed a wider area of the posterior interior side and posterior lateral side of the tibial plateau by passing below the popliteus; and protected the tibial nerve and popliteal artery and vein with the popliteus and medial gastrocnemius muscle when the posterior lateral side of the tibial plateau was exposed. Operative injuries easily occurred when the anterior tibial artery penetrated the interosseous membrane. The penetration was under the tibial plateau, 59.44±3.97mm(length of Line B) away from the tibial plateau vertically in males, and 58.67±1.37mm(length of Line B) in females; 38.72±3.54mm(length of Line A) away from the tibial posterior interior edge horizontally in males, and 36.93±1.88mm(length of Line A) in females. The developed medial gastrocnemius muscle or part of it needed to be cut off in some patients. The nerve innervating the muscle from the entry point to the start of the muscle is 40.07±3.19 mm long(length of Line C) in males, and 40.67±2.98 mm long(length of Line C). Cut-off that was within 30 mm below the start of the medial gastrocnemius muscle entailed no injury.2. Results of clinical application: all of patients in this group were visited in the regular follow-ups that spanned an average period of 14.5 months(12- 18 months), and the average fracture healing time was 15.4 weeks(12-16 weeks). The Rasmussen scores obtained right after the surgery were 14-18 with the average being 16. The HSS knee scores in the last follow-up averaged 93 with the good rate being 100%, and their range of motion of knee joint were between 0° to 128°. As the TPA right after the surgery was 5.16±0.59°, and that 12 months after the surgery was 5.16±0.59°, t value was 0.00, P value was 1.00, and P>0.05 meaning that there were no significant differences; as the FTA right after the surgery was 170.32±2.75°, and that 12 months after the surgery was 170.14±2.66°, t value was 1.964, P value was 0.1211 and P>0.05 meaning that there were no significant differences. Conclusions:After the anatomical research and clinical application of inverted L-shaped in the posterior aspect of knee joint were carried out, the results indicated that the inverted L-shaped in the posterior aspect of knee joint in the treatment of posterior column fracture in tibial plateau was easier and safer, caused fewer injuries, and exposed enough, applicable to the treatment of the complex posterior column fracture in tibial plateau and both post columns fracture. With better effects in the clinical application, this approach is worth promoting in clinical practice.