Clinical Significance of a Novel Knee Joint Stability Assessment System for Evaluating Anterior Cruciate Ligament Deficient Knees.

OBJECTIVE: To investigate the six degrees of freedom (6DOF) kinematics of anterior cruciate ligament (ACL) deficient knees during gait and to explore the clinical significance of a novel knee joint stability assessment system (Opti_Knee, Innomotion, Shanghai, China) in comparison with imaging and arthroscopic examination. METHODS: Three subjects diagnosed with ACL deficient knees on the basis of preoperative MRI and CT findings were subjected to treadmill gait analysis. Motion of both knees in 6DOF was measured and analyzed with an optical joint kinematics measurement system. Arthroscopic examination, the gold standard, was performed to confirm the final diagnosis and the clinical diagnosis of ACL deficiency by imaging and motion marker techniques compared with this gold standard. RESULTS: Only two of the three subjects diagnosed with ACL deficiency by imaging techniques were later confirmed to have this condition by arthroscopic examination; the third was found to have an intact ACL. When the kinematics of their injured and contralateral knees were compared, abnormalities were found in the two subjects confirmed by arthroscopy to be ACL deficient However, no kinematic difference between the two knees was found in the ACL intact subject. CONCLUSIONS: Opti_Knee (Innomotion) can detect abnormal kinematics in ACL deficient knees and thus provides an effective way of assisting the diagnosis of this condition and has potential for clinical application.

Biomechanics of single-tunnel double-bundle anterior cruciate ligament reconstruction using fixation with a unique expandable interference screw.

BACKGROUND: Single-tunnel double-bundle (STDB) anterior cruciate ligament (ACL) reconstruction can restore biomechanical function and anatomic structure, but existing methods of graft fixation are not adequate. The aims of this study are to examine knee biomechanics after STDB reconstruction using a unique expandable interference screw for fixation. METHODS: The biomechanical parameters of six pairs of human cadaveric knee specimens were measured with the ACL intact, after ACL removal, and after STDB reconstruction using the interference screw or single-tunnel single-bundle (STSB) reconstruction. Anterior tibial translation under 134 N anterior tibial load in a neutral position as well as in 15° and 30° internal and external knee rotation and the internal tibial rotation angle under the rotatory load (5 N·m internal tibial rotation) were measured. RESULTS: Anterior tibial translations at each degree of knee flexion in the STDB group were significantly less than in the STSB group (all, P<0.05). The internal rotation angles in the STSB group at five flexion angles were significantly higher than in the ACL intact group, whereas there were significantly less than those of the ACL absent group (P<0.05). Under rotatory loads in the neutral position, the tibial internal rotation angles of the STDB group were significantly lower than in the STSB group at all flexion angles (all, P<0.05). CONCLUSIONS: STDB ACL reconstruction with the expandable interference screw provides better anteroposterior and rotational stability than STSB reconstruction. CLINICAL RELEVANCE: The technique provides the advantages of double-bundle reconstruction using a single-tunnel technique.

[Features of the dual energy technique with dual-source computed tomography for anterior cruciate ligament injuries].

OBJECTIVE: To explore the diagnostic value of the dual-energy technique with dual-source computed tomography (DSCT) for anterior cruciate ligament injuries. METHODS: The clinical data of 8 patients with arthroscopic results were retrospectively reviewed. All patients underwent two- and three-dimensional imaging by multiplanar reconstruction, volume rendering, and tendon mode on DSCT. Dual-energy characteristics were compared with arthroscopic results. RESULTS: Six patients who were arthroscopically diagnosed as anterior cruciate ligament injuries, all of them were also correctly diagnosed by DSCT. Two patients who were arthroscopically diagnosed as normal, one was also diagnosed as normal by DSCT and the other was misdiagnosed. The overall agreement rate was 87.5% (7/8) . Under the dual energy tendon mode, the dual energy staining of the injured anterior cruciate ligament was lower than that of the contralateral normal cruciate ligament of the patient. CONCLUSION: The staining diminution in DSCT imaging may be a new feature that can be used to effectively diagnose anterior cruciate ligament injury.

[Preparation of cisplatin-impregnated coral hydroxyapatite drug delivery system].

OBJECTIVE: To prepare a cisplatin-impregnated coral-derived hydroxyapatite (CCHA) drug delivery system (DDS), and evaluate its inhibitory effect on human osteosarcoma cells U-2 OS, human breast cancer and prostatic carcinoma cells PC-3 in vitro. METHODS: The coral-derived hydroxyapatite (CHA) was manufactured by hydrothermal exchange and impregnated with cisplatin by vacuum freeze-drying techniques. The leaching solutions of this DDS was collected at different intervals in a course of 8 weeks and their inhibitory effect on the cells was tested in vitro by MTT assay. RESULTS: Electron microscope showed that cisplatin was distributed homogeneously in the pores of CHA. The inhibition rates of the leaching solution on all the tumor cells exceeded 50% except for PC-3 cells, whose inhibition rate was 29.92% when treated with the solution collected at the eighth week. CONCLUSION: CCHA allows sustained drug release and maintains excellent inhibitory effect on human bone tumor cells within 8 weeks in vitro.

[Results of 1310 knees of meniscal treatment evaluated by arthroscopy].

OBJECTIVE: To evaluate results of 1310 knees of meniscal treatments by arthroscopy and to present good method of meniscal treatment. METHODS: Their age, traumatic mechanism and effects under arthroscopy were analysed in a series of 254 patients with meniscal injuries, there were 880 males and 374 females, the average of the patients was 25.5 years. The meniscal repair in 68 knee, partial meniscectomy in 756 knee, total meniscectomy in 480 knee and conservative treatment in 6 cases. RESULTS: The patients were followed up 1 to 12 years with the average of 4 years and 3 months. The mean Lysholm score was 86.3 points in arthroscopic meniscal repair, 84.0 points in partial meniscectomy and 76.1 points in total meniscectomy. The mean Lysholm 98.7 points in all children patients with conservative treatment. They showed significant difference (P < 0.01) in the results of three treatments. CONCLUSIONS: Meniscal injuries should not cut off as it, should be repaired in 5 mm from meniscus to synovium and or partial meniscectomy. The general adoption is not the surgical operation on meniscal injuries of the child.

[Biomechanical response of the femur-tibia model under impact loading of the body weight].

OBJECTIVE: To study the biomechanical response and the role of articular surface on the femur-tibia model under impact loading of the body weight. METHODS: A three-dimensional finite element (FE) model of the femur-tibia composite was reconstructed using the image data of the knee joint of Virtual Chinese Human No.1 Male, and FE calculation was performed to simulate the impact of the body weight on the knee joint while walking. RESULTS: The femur-tibia composite was compressed during the impact with obvious protrusive movement. Diffusion and attenuation of the stress occurred during its conduction to the articular surface. CONCLUSION: The femur-tibia composite is unstable under the vertical impact loading of the body weight, with obvious protraction movement, and the articular surface may serve as the buffer of the impact.

[Comparative clinical observation of the short-term bone fusion effect of composite biosynthetic bone and ilium auto-grafting].

OBJECTIVE: To evaluate the short-term bone fusion after implantation of composite biosynthetic bone made of coralline hydroxyapatite composite (CHC) as a substitute for autologous bone grafting. METHODS: A clinical sequential trial was designed and the biosynthetic bone and the patient's ilium were respectively used in the treatment of femoral nonunions and interbody fusion. X-ray examinations were performed 10 weeks after the operations and the bone fusion was graded according to Lane-Sandhu's method. RESULTS: The biosynthetic bone was capable of bone fusion as observed in this experiment. Sequential analysis found that the upper bound was reached when the X-ray examination scores of 15th pairs were transcribed in the chart with 2 pairs of cases dismissed for having the same grade. CONCLUSION: The bone fusion effect of CHC is better than auto-grafting judging from the present observation at 10 weeks after operation.

[The reason and prevention of upper cervical reoperations].

OBJECTIVE: To discuss the reasons for the operation performed on 13 patients with upper cervical disease and to explore the management and prevention of upper cervical disease. METHODS: Thirteen patients with upper cervical disease were retrospectively reviewed. The reason for of reoperations on these patients were analyzed. The measures to reduce upper cervical operational complication and bad prognosis were discussed to avoid reoperations. RESULTS: The reasons for reoperations included 9 cases with unstable or re-dislocated atlantoaxial joint, 10 cases with residual spinal cord compression, 1 case with malposition of odontoid screw, 1 case with adjacent cervical spine regression, 1 case with occipital-cervical fusion failure, 1 case with spinal cord injury during operation, 1 case with bone-plant slipped into canales spinalis, and 1 case with demand to take out internal fixation for aggravated symptom. CONCLUSIONS: The common reasons for upper cervical reoperations were due to instability or redislocation of atlantoaxial joint and residual of spinal cord compression. Some measures such as reducing operate miss, using firm internal fixation and decompressing were advisable to decrease the incidence of reoperations.