【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.
ObjectiveTo analyze the reasons and the influence of internal fixation about the guide pin eccentricity of helical blade during proximal femoral nail anti-rotation (PFNA) internal fixation for femoral intertrochanteric fractures.MethodsA retrospective analysis of the intraoperative imaging data of 175 patients with femoral intertrochanteric fractures, who underwent closed reduction and PFNA internal fixation between January 2018 and January 2020, was performed. There were 76 males and 99 females with an average age of 79.8 years (mean, 61-103 years). The internal between admission and operation was 12-141 hours (median, 32 hours). According to AO/Orthopaedic Trauma Association (AO/OTA) classification, the fractures were rated as type 31-A1 in 64 cases and type 31-A2 in 111 cases. In the intraoperative fluoroscopy image by C-arm X-ray machine, the caputcollum-diaphysis (CCD) was measured after closed reduction and internal fixation, respectively; the angles between the center line of the head nail hole and the axis of proximal nail and between the axis of guide pin and proximal nail were measured, and the difference between the two angles was evaluated; the quality of fracture reduction was evaluated according to the alignment of the medial cortex, anterior cortex of the head and neck bone block, and femoral shaft cortex; the position of the helical blade in the femoral head was evaluated according to the Cleveland method.ResultsThe CCDs of proximal femur were (134.6±6.8)° after closed reduction and (134.9±4.3)° after internal fixation. There was no significant difference between pre- and post-internal fixation (t=0.432, P=0.766). The angles between the center line of the head nail hole and the axis of proximal nail and between the axis of guide pin and proximal nail were (125.4±2.44)° and (126.3±2.3)°, respectively, showing significant difference (t=2.809, P=0.044). The difference between the two angles was (0.8±2.2)°. The guide pin eccentricity of helical blade occurred in 47 cases. After tapping the helical blade along the eccentric guide pin, 10 cases had fracture reduction loss, and 5 cases had a poor position of the helical blade in the femoral head. ConclusionDuring PFNA internal fixation, a variety of reasons can lead to the eccentric position of the guide pin of helical blade, including unstable fracture, soft tissue inserted, severe osteoporosis, mismatched tool, and fluoroscopic imaging factors. It is possible that the fracture end would be displaced again and the helical blade position may be poor when knocking into the helical blade along the eccentric guide pin. During operation, it should be judged whether the direction of the guide pin needs to be adjusted according to the eccentric angle.