Objective To evaluate the survival condition and quantitative variation of mechanoreceptors in the tibial remnant of ruptured anterior cruciate l igament (ACL) in human knees. Methods Between April 2009 and May 2010, 60 patients who underwent arthroscopic ACL reconstruction were included and divided into 4 groups according to the time of injury, with 15 patients in each group. In group A, there were 14 males and 1 female aged 20-37 years (mean, 27 years); the injury was caused by traffic accident in 5 cases and by sports in 10 cases, and the time between injury and surgery was not more than 3 months. In group B, there were 14 males and 1 female aged 17-43 years (mean, 24 years); the injury was caused by traffic accident in 2 cases and by sports in 13 cases; and the time between injury and surgery was 3 to 6 months. In group C, there were 11 males and 4 females aged 16-53 years (mean, 28 years); the injury was caused by traffic accident in 2 cases and by sports in 13 cases; and the time between injury and surgery was 6 to 12 months. In group D, there were 12 males and 3 females aged 18-41 years (mean, 26 years); the injury was caused by sports in 11 cases, and the other 4 cases had no defined etiology; and the time between injury and surgery was more than 12 months. Specimens were donated by the volunteers from the anteromedial side of the ACL tibial remnant (40 sl ices per specimen) and stained via immunohistochemical method. The type, size, and quantity of mechanoreceptors were observed under l ight microscope. Results Totally 80 Ruffini-l ike corpuscles, 8 Pacini-l ike corpuscles, 5 atypical neural endings and no distinct Golgi organ-l ike corpuscles were observed under l ight microscope in 60 specimens (2 400 sl ices) of 4 groups. There was no obvious difference in size and type of mechanoreceptors among 4 groups. However,some degenerative and atrophic changes could be observed in the specimens of group D. The total number of echanoreceptors was 31 (35.2%) in group A, 22 (25.0%) in group B, 23 (26.1%) in group C, and 12 (13.7%) in group D. There was no significant difference (P gt; 0.05) in Ruffini-l ike corpuscles and Pacini-l ike corpuscles among 4 groups. Mechanoreceptors were found in 9,8, 9, and 6 patients in groups A, B, C, and D, respectively; the detection rates were 60.0%, 53.3%, 60.0%, and 40.0%, respectively; showing no significant difference (P gt; 0.05). Conclusion The mechanoreceptors in tibial residual of ruptured ACL have a long survival without obvious degeneration and atrophy within 12 months. So it may contribute to restoration of proprioceptive function after operation if the remnant is preserved during ACL reconstruction.
Objective To explore latest changes of joint proprioceptive function after posterior cruciate l igament (PCL) reconstruction using double-bundle semitendinosus and gracil is under arthroscope. Methods From June 2001 to November 2002, 25 patients with PCL ruptures were treated by arthroscope PCL reconstruction using double-bundle semitendinosus and gracil is, among whom 19 were males and 6 were females, aged 16-58 years old (36 on average). There were 6 cases of exercise injury, 15 of vehicle accident and 4 of fall ing injury. The duration before the operation was 1 week to 4 months (2.5 months on average). The posterior drawer test showed 23 patients were positive and 2 patients in the acute stagewere not cooperative. MRI indicated that all the patients had PCL injuries. The proprioceptive function of the knee joints was (4.73 ± 0.12)° before operation. Results All patients’ incisions obtained heal ing by first intention after the operation. The posterior drawer test showed that all the patients were negative. All 25 patients were followed up for 20-41 months (30.1 months on average). Eighteen months after operation, MRI indicated that bone marrow canal healed and internal fixation was stable. At the time of the last follow-up, the Lysholm score increased from (58.6 ± 15.2) before operation to (93.2 ± 7.4), and there was statistical difference (P lt; 0.05). The proprioceptive function of the knee joints was (5.67 ± 0.32)°, (5.45 ± 0.16)°, (3.80 ± 0.01)° and (3.67 ± 0.25)° at 5, 10, 15 and 20 months after operation, respectively. Statistical differences were observed between groups at 5, 10, 15, 20 months and the group before operation (P lt; 0.05). The proprioceptive function of the knee joints was (4.56 ± 0.11)° at the final follow-up, and was significantly different from that of the normal knee joints was (2.13 ± 0.41)°, (P lt; 0.05). Conclusion Joint proprioceptive function decreases temporally after the arthroscopy PCL reconstruction and begins to restore 15 months after operation, and improves sharply 20 months after operation. All patients’ Lysholm scores and symptoms improve after operation. Therefore, the operation is effective.