ObjectiveTo investigate the correlation between graft maturity and knee function after anterior cruciate ligament (ACL) reconstruction.MethodsA total of 50 patients who underwent ACL reconstruction with autologous tendons between August 2016 and August 2018 were included in the study. There were 28 males and 22 females, with an average age of 31.0 years (range, 18-50 years). At 6 months and 2 years after operation, the signal to noise quotient (SNQ) values of tibial and femoral ends of graft were measured by MRI, and the mean value was taken as the SNQ value of graft. The function of knee joint was evaluated by Tegner, Lysholm, and International Knee Documentation Committee (IKDC) scores. The differences in SNQ values between tibial and femoral ends were analyzed at 6 months and 2 years after operation. The correlation between SNQ value at 6 months after operation and knee function score at 2 years after operation was analyzed. According to SNQ value at 6 months after operation, the patients were divided into group A (SNQ value≥12) and group B (SNQ value<12) and the correlation between SNQ value and knee function score was further analyzed.ResultsAll incisions healed primarily without infection or injury of blood vessels and nerves. All patients were followed up 24-28 months (mean, 26.6 months). The IKDC, Lysholm, and Tegner scores at 6 months and 2 years after operation were significantly higher than those before operation (P<0.05), and all scores at 2 years after operation were also significantly higher than those at 6 months (P<0.05). The SNQ values at 6 months and 2 years after operation were 12.517±6.272 and 10.900±6.012, respectively, and the difference was significant (t=1.838, P=0.007). The SNQ values of graft at 6 months after operation were significantly different from those at 2 years after operation (P<0.05), and the SNQ values of tibial and femoral ends of graft at the same time point were significantly different (P<0.05). The SNQ value of 50 patients at 6 months after operation was negatively correlated with Lysholm, IKDC, and Tegner scores at 2 years after operation (r=–0.965, P=0.000; r=–0.896, P=0.000; r=–0.475, P=0.003). The patients were divided into groups A and B according to the SNQ value, each with 25 cases; the SNQ values of the two groups at 6 months after operation were negatively correlated with Lysholm, IKDC, and Tegner scores at 2 years after operation (P<0.05).ConclusionAfter ACL reconstruction, the knee function scores and graft maturity of patients gradually improved. The lower the SNQ value in the early stage, the higher the knee function score in the later stage. The SNQ value of MRI in the early stage after ACL reconstruction can predict the knee function in the later stage.
ObjectiveTo investigate the influence of lateral posterior tibial slope (LPTS) on tibial tunnel expansion after anatomical single-bundle anterior cruciate ligament (ACL) reconstruction and the effect of tibial tunnel expansion on knee joint function.MethodsA clinical data of 52 patients with ACL rupture, who underwent arthroscopic anatomical single-bundle reconstruction between November 2018 and December 2019, was retrospectively analyzed. There were 32 males and 20 females with an average age of 34.3 years (range, 14-64 years). There were 22 cases of left knee and 30 cases of right knee. The time from injury to operation ranged from 7 to 30 days, with an average of 15.9 days. The knee function was evaluated by International Knee Documentation Committee (IKDC) score and Lysholm score before operation and at 3 and 6 months after operation. At 3 and 6 months after operation, the LPTS and the width of exit, middle segment, entrance, and 2 cm from the exit of the articular surface of the tibial tunnel were measured based on MRI. The expansion of tibial tunnel was calculated and graded (degrees 0-3). According to LPTS, the patients were divided into group A (<6.0°), group B (6°-12°), and group C (>12°), and the difference in the expansion of tibial tunnel between groups was compared.ResultsAll the 52 patients were followed up 6-12 months (mean, 7.1 months). The IKDC and Lysholm scores at 3 and 6 months after operation were significantly different from those before operation (P<0.05); and the difference of knee scores between 3 and 6 months after operation was significant (P<0.05). The tibial tunnel expanded after operation, and the relative expansion at the exit and the middle segment showed significant difference between 3 months and 6 months after operation (P<0.05). The expansion degree of tibial tunnel was rated as degree 0 in 5 cases, degree 1 in 28 cases, degree 2 in 16 cases, and degree 3 in 3 cases at 3 months after operation, and degree 0 in 5 cases, degree 1 in 20 cases, degree 2 in 25 cases, and degree 3 in 2 cases at 6 months after operation. There was no significant difference in IKDC and Lysholm scores between patients with different expansion degrees of tibial tunnels (P>0.05). The LPTS of 52 patients ranged from –0.8° to 18.7° (mean, 10.6°); there were 7 cases in group A, 24 cases in group B, and 21 cases in group C. There was no significant difference in age, gender, preoperative IKDC and Lysholm scores, and initial width of tibial tunnel between groups (P>0.05). There was no significant difference in the relative expansion of tibial tunnel at exit and middle segment between groups at 3 months after operation (P>0.05), and there was significant difference at 6 months after operation (P<0.05).ConclusionAfter anatomical single-bundle reconstruction of ACL, the tibial tunnel would expand to some extent in a short time. LPTS had a significant effect on tibial tunnel expansion, and the larger the angle was, the more obvious the expansion of the proximal tibial tunnel was. However, early knee function is not affected by tibial tunnel expansion.
Objective To develop and validate a nomogram prediction model of early knee function improvement after total knee arthroplasty (TKA). Methods One hundred and sixty-eight patients who underwent TKA at Sichuan Province Orthopedic Hospital between January 2018 and February 2021 were prospectively selected to collect factors that might influence the improvement of knee function in the early postoperative period after TKA, and the improvement of knee function was assessed using the Knee Score Scale of the Hospital for Special Surgery (HSS) at 6 months postoperatively. The patients were divided into two groups according to the postoperative knee function improvement. The preoperative, intraoperative and postoperative factors were compared between the two groups; multiple logistic regression was performed after the potential factors screened by LASSO regression; then, a nomogram predictive model was established by R 4.1.3 language and was validated internally. Results All patients were followed up at 6 months postoperatively, and the mean HSS score of the patients increased from 55.19±8.92 preoperatively to 89.27±6.18 at 6 months postoperatively (t=−40.706, P<0.001). LASSO regression screened eight influencing factors as potential factors, with which the results of multiple logistic regression analysis showed that preoperative body mass index, etiology, preoperative joint mobility, preoperative HSS scores, postoperative lower limb force line, and postoperative analgesia were independent influencing factors for the improvement of knee function in the early postoperative period after TKA (P<0.05). A nomogram model was established based on the multiple logistic regression results, and the calibration curve showed that the prediction curve basically fitted the standard curve; the receiver operating characteristic curve showed that the area under the curve of the nomogram model for the prediction of suboptimal knee function in the early postoperative period after TKA was 0.894 [95% confidence interval (0.825, 0.963)]. Conclusions There is a significant improvement in knee function in patients after TKA, and the improvement of knee function in the early postoperative period after TKA is influenced by preoperative body mass index, etiology, and preoperative joint mobility, etc. The nomogram model established accordingly can be used to predict the improvement of knee function in the early postoperative period after TKA with a high degree of differentiation and accuracy.