【Abstract】 Objective To investigate the early effectiveness of the Discover cervical artificial disc replacement in treating cervical spondylosis. Methods Qualified for the selective standard, 24 patients with cervical spondylosis were treated between March 2010 and March 2011. Of 24 patients, 13 patients underwent anterior cervical decompression and fusion (ACDF) (ACDF group, between March 2010 and September 2010) and 11 patients underwent Discover cervical artificial disc replacement (CADR group, between September 2010 and March 2011). There was no significant difference in gender, age, disease duration, lesions typing, and affected segments between 2 groups (P gt; 0.05). The operative time, blood loss, and complications were recorded. Japanese Orthopaedic Association (JOA) scores, Neck Disability Index (NDI) scores, and Odom’s scores were used to evaluate the postoperative effectiveness. In CADR group, the cervical range of motion (ROM) in all directions, and prosthesis eccentricity were measured before and after operation. Results Symptoms disappeared and no complication occurred after operation in the patients of 2 groups. The patients were followed up 12 to 18 months (mean, 15.3 months) in ACDF group and 6 to 12 months (mean, 9.6 months) in CADR group. The NDI scores in CADR group were significantly higher than those in ACDF group at 1, 3, and 6 months (P lt; 0.05), but no significant difference was observed in JOA score improvement rate between 2 groups (P gt; 0.05). According to Odom’s score at last follow-up, the results were excellent in 6 cases, good in 4 cases, and fair in 3 cases with an excellent and good rate of 76.92% in ACDF group, and were excellent in 9 cases, good in 1 case, and poor in 1 case with an excellent and good rate of 90.91% in CADR group, showing no significant difference (χ2=3.000, P=0.223). The patients in CADR group had significant limit of cervical joint ROM in flexion and extension and right bending at 1 month (P lt; 0.05), but cervical joint ROM restored after 3 months. The ROMs of left bending at 3 months and 6 months were bigger than preoperative value (P lt; 0.05). Meanwhile, ROM in left bending were bigger than that in right bending in replaced segment and upper segment (P lt; 0.05), and the ROM difference between left bending and right bending in upper segment was 2 times higher than that in the replaced segment; a marked linear correlation (P lt; 0.05) existed between the ROM difference and prosthesis eccentricity, and prosthesis bias had bigger ROM in lateral bending. Conclusion Discover cervical artificial disc replacement for treatment of cervical spondylosis can provide a good effectiveness and cervical postoperative movement function. As a new prosthesis, it has some merits such as simple operative steps and less complications.
Objective To observe the posterior condylar offset (PCO) changes and anteroposterior femorotibial translation, to investigate the influence of them on the maximum knee range of flexion (ROF) in patients with posterior cruciatesacrificingself al ignment bearing total knee arthroplasty (TKA). Methods The cl inical data were analyzed retrospectively from 40 patients (40 knees) undergoing primary unilateral TC-PLUSTM SB posterior cruciate-sacrificing self al ignment andbearing TKA for osteoarthritis between January 2007 and June 2009. There were 18 males and 22 females with an average age of 70.6 years (range, 56-87 years). The disease duration was 5-14 years (mean, 9.1 years). The locations were the left side in 11 cases and the right side in 29 cases. Preoperative knee society score (KSS) and ROF were 48.0 ± 5.5 and (77.9 ± 9.0)°, respectively. The X-ray films were taken to measure PCO and anteroposterior femorotibial translation. Multi ple regression analysis was performed based on both the anteroposterior femorotibial translation and PCO changes as the independent variable, and maximum knee flexion as the dependent variable. Results All incisions healed by first intention. The patients were followed up 12-19 months (mean, 14.7 months). At last follow-up, there were significant differences in the KSS (91.9 ± 3.7, t=— 77.600, P=0.000), the ROF [(102.0 ± 9.3)°, t=— 23.105, P=0.000] when compared with preoperative values. Significant difference was observed in PCO (t=3.565, P=0.001) between before operation [(31.6 ± 5.5) mm] and at last follow-up [(30.6 ± 5.9) mm]. At ast follow-up, the anteroposterior femorotibial translation was (— 1.2 ± 2.1) mm (95%CI: — 1.9 mm to — 0.6 mm); femoral roll forward occurred in 27 cases (67.5%), no roll in 1 case (2.5%), and femoral roll back in 12 cases (30.0%). By multiple regression analysis (Stepwise method), the regression equation was establ ished (R=0.785, R2=0.617, F=61.128, P=0.000). Anteroposterior femorotibial translation could be introducted into the equation (t=7.818, P=0.000), but PCO changes were removed from the equation (t=1.471, P=0.150). Regression equation was y=25.587+2.349x. Conclusion Kinematics after TC-PLUSTM SB posterior cruciate-sacrificing self al ignment bearing TKA with posterior cruciate l igament-sacrificing show mostly roll forwardof the femur relative to the tibia, which have a negative effect on postoperative range of motion. There is no correlation between PCO changes and postoperative change in ROF in TC-PLUSTM SB posterior cruciate-sacrificing self al ignment bearing TKA.
Objective To design an open shape memory alloy artificial vertebral body that can be used to reconstruct the vertebral body in spine diseases, such as thoracic-lumbar spine tumors, burst fracture of the vertebrae, kyphosis and scol iosis, and to evaluate the biomechanical stabil ity of lumbar functional segment unit after insertion with the shape memoryalloy artificial vertebral body. Methods The open shape memory alloy artificial vertebral body with nickel-titanium (NiTi)alloy was made. Eight fresh spine specimens (T14-L5) from normal adult porcine were used to detect the range of motion (ROM) in 4 models and were divided into 4 groups: intact vertebrae served as group A; pedicle screw fixation of T15, L1, L3, and L4 was given in group B; after total resection of L2, it was reconstructed by open shape memory alloy artificial vertebral body combined with pedicle screw fixation of T15, L1, L3, and L4 in group C; and after total resection of L2, it was reconstructed by titanium cage vertebral body combined with pedicle screw fixation of T15, L1, L3, and L4 in group D. The three-dimensional ROM of flexion, extension, left/right lateral bending, and left/right rotation in T15-L1, L1-3, and L3,4 segments were detected in turn by the spinal three-dimensional test machine MTS-858 (load 0-8 N•m). Results Compared with group A, groups B, C, and D had good stabil ity in flexion, extension, left/right lateral bending, and left/right rotation, showing significant differences (P lt; 0.05). There was no significant difference in the degree of each motion between group B and group C (P gt; 0.05). Group C had less degree of motion in T15-L1 and L3,4 segments than group D, showing significant differences (P lt; 0.05), but there was no significant difference in L1-3 segment (P gt; 0.05). Conclusion The open shape memory alloy artificial vertebral body has a reasonable structure and good biomechanical stabil ity, it can be used to stabil ize the spinal segment with pedicle screw fixation.
ObjectiveTo explore the therapeutic effect of total hip arthroplasty (THA) and hip adductor amputation (HAA) in the surgical treatment of osteonecrosis of femoral head. MethodsA total of 74 patients with osteonecrosis of femoral head with hip adduction deformity were included between June 2011 and May 2012. Among them, 38 patients had undergone THA, and 36 patients had undergone THA+HAA. Statistics about hip abductor function and Harris scores before and 1 week and 12 months after the surgery were recorded. SPSS 19.0 was used for statistical analysis. ResultsThe patients' wounds had the Ⅰ-stage healing in both of the two groups. Two patients had scrotum swelling in THA+HAA group, who left the hospital after treating. One week after the surgery, the hip passive abduction angles increased (32.1±2.8) and (19.7±3.3)°, respectively in the THA+HAA group and THA group, while the Harris hip score increased 45.8±2.8 and 40.9±2.3, respectively; 12 months postoperatively, the hip passive abduction angles increased (32.2±0.9) and (26.8±2.8)°, respectively in the THA+HAA group and THA group, while the Harris hip score increased 52.7±7.2 and 49.4±4.4, respectively. The above comparative differences was statistically significant (P<0.05). ConclusionThe surgical method of adductor amputation can improve the range of motion of the hip, raise the quality of life of the patients with osteonecrosis of the femoral head after the surgery.
ObjectiveTo evaluate the effectiveness of the single segmental cervical disc replacement with ProDisc-C, and to explore the location change of the flexion/extension center of rotation (COR) of the target level as well as its clinical significance. MethodsBetween June 2010 and February 2012, 23 patients underwent single segmental cervical disc replacement with ProDisc-C, and the clinical data were retrospectively analyzed. Of 23 patients, 9 were male, and 14 were female with the age range from 27 to 65 years (mean, 45 years), and the disease duration ranged from 10 to 84 months (mean, 25 months). There were 15 patients with radiculopathy, 5 patients with myelopathy, and 3 patients with mixed cervical spondylosis. The involved segments were C4,5 in 5 cases, C5,6 in 14 cases, and C6,7 in 4 cases. Japanese Orthopaedic Association (JOA) score and neck disability index (NDI) were adopted to evaluate the effectiveness. Preoperative and Postoperative radiographic parameters, such as cervical overall range of motion (ROM), target segmental ROM, the adjacent segmental ROM, and intervertebral height were compared. Besides, the location changes of the COR of the target level were further analyzed by the alteration of its coordinates (COR-X,COR-Y), and the relationships between the location changes of the COR and the effectiveness or the radiographic results were analyzed. ResultsAll the operations were completed successfully; 1 case had hoarseness after operation, which disappeared at 3 months after operation. All cases were followed up 18.3 months on average (range, 6-36 months). There was no device migration, loosening, subsidence, or fracture at last follow-up. The JOA score increased significantly and the NDI score decreased significantly at last follow-up when compared with preoperative scores (P<0.05). No difference was found in the cervical overall ROM, target segmental ROM, the adjacent segmental ROM, and the COR-Y of the target level between pre-operation and last follow-up (P>0.05); while the intervertebral height and the COR-X increased significantly (P<0.05). The change of the COR-X had no obvious correlation with the postoperative JOA, NDI, and target segmental ROM (P>0.05). According to whether the difference of the COR-X between pre- and post-operation was less than the average value 1.86 mm or not, the patients were divided into 2 groups; significant difference was shown in the postoperative target segmental ROM between 2 groups (P<0.05), but no significant difference was found in the postoperative JOA、NDI, cervical overall ROM, adjacent segmental ROM, and the intervertebral height between 2 groups (P>0.05). ConclusionSingle segmental cervical disc replacement with ProDisc-C can obtain satisfactory outcomes. The cervical overall ROM, target segmental ROM, and adjacent segmental ROM can be effectively maintained, and the intervertebral height is increased. The location of the flexion/extension COR of the target segment shifts forward after insertion of the ProDisc-C prosthesis, and the postoperative target segmental ROM becomes smaller as the distance of the displacement of the COR becomes greater.
This article introduces the methods about how to use the summary statistics such as the sample median, minimum and maximum to estimate the sample mean and standard deviation for continuous outcomes. For the purpose of illustration, we also apply the existing methods to a real data example.