To compare between the CAMISS-TLIF group and the OP-TLIF group in the clinical efficacy and radiographic manifest. This study was a registration study, selected 27 patients with lumbar spondylolisthesis from May 2011 to March 2014 in our hospital. Patients in one group are treated with computer assisted navigation minimally invasive TLIF (CAMISS -TLIF) while the others are treated with the OP-TLIF (OPEN-TLIF). The former group has 13 cases while the latter group has 14 cases. We collected information and present statistical analysis on the following aspects in order to compare the two different surgical methods of treatment. They are the operation duration, blood loss, days of hospitalisation, the preoperative and follow-up JOA and JOA improvement rate, the preoperative and follow-up ODI scores, the preoperative and follow-up VAS and Odom's criteria. By analysing the follow-up CT results, we compare the pedicle screw accuracy rate between the two groups in order to make a comprehensive assessment of these two surgical methods.Objective
Methods
Computer based navigation system improved the accuracy of limb and component alignment and decreased the incidence of outliers. The majority of previous studies were based on the infrared navigation system. We evaluate the availability and accuracy of the electromagnectic(EM) navigation system in total knee arthroplasty From July 2006 to January 2007, 40 patients (50 TKAs) with osteoarthritis were participated in this study. AxiEM(Medtronics) was used and Nexgen CR(26 cases), and Nexgen CR flex(24 cases) were used. We analyzed the failure mode of navigation (7 cases), operation time and radiologic results (limb and component alignment) Total registration time was 4 minutes 45 seconds in average (Range: 3 minutes 45 seconds – 6 minutes 55 seconds). Failures in clinical applications resulted from non-recognition of EM tracker or paddle by metallic interference in 4 cases and from informational changes during surgery by fixation loss or loosening of the tracker in 3 cases. Radiologically, the mechanical axis changed from −11.2±7.21 (Range: −25.8~3.1) to 1.0±1.25(Range: −2.1~4.0) and 1 case of outlier occurred (valgus 4°). Component alignment is measured as followed: 89.3±1.6° of Theta angle, 89.9±1.5° of Beta angle, 1.8±2.5° of Gamma angle, 86.1±2.9 of Delta angle°. There were no complications related to the EM navigation. The EM navigation system helped to achieve accurate alignment of component and lower leg axis without any complications. It had several advantages such as relatively less invasiveness in fitting small instruments, not disturbing operation field, no interrupted line of sight, portable use, and applicability to any implant. However, metallic interference may be still problematic. The EM navigation had advantages; less invasiveness, no disturbing operation field, no interrupted line of sight, portable use and applicability to any implants. But metallic interference may be still problematic.
Bilateral sequential total knee replacement with a Zimmer NexGen prosthesis (Zimmer, Warsaw, Indiana) was carried out in 30 patients. One knee was replaced using a robotic-assisted implantation (ROBOT side) and the other conventionally manual implantation (CON side). There were 30 women with a mean age of 67.8 years (50 to 80). Pre-operative and post-operative scores were obtained for all patients using the Knee Society (KSS) and The Hospital for Special Surgery (HSS) systems. Full-length standing anteroposterior radiographs, including the femoral head and ankle, and lateral and skyline patellar views were taken pre- and post-operatively and were assessed for the mechanical axis and the position of the components. The mean follow-up was 2.3 years (2 to 3). The operating and tourniquet times were longer in the ROBOT side (p <
0.001). There were no significant pre- or post-operative differences between the knee scores of the two groups (p = 0.288 and p = 0.429, respectively). Mean mechanical axes were not significantly different in the two groups (p = 0.815). However, there were more outliers in the CON side (8) than in the ROBOT side (1) (p = 0.013). In the coronal alignment of the femoral component, the CON side (8) had more outliers than the ROBOT side (1) (p = 0.013) and the CON side (3) also had more outliers than the ROBOT side (0) in the sagittal alignment of the femoral component (p = 0.043). In terms of outliers for coronal and sagittal tibial alignment, the CON side (1 and 4) had more outliers than the ROBOT side (0 and 2). In this series robotic-assisted total knee replacement resulted in more accurate orientation and alignment of the components than that achieved by conventional total knee replacement.
The study is to evaluate mid-term follow-up clinical results and navigation prediction of the first 106 TKAs, which was performed based on the soft tissue balancing technique using the OrthoPilot navigation system (B.Braun Aesculap, Tuttlingen, Germany). All the 106 cases were diagnosed as osteoarthritis with varus deformity. After anatomical and kinematic registration, the mechanical axis was restored to neutral (±2°) at full extension with step by step meticulous medial soft tissue release and osteophyte removal. Proximal tibial bone cutting was performed under real-time navigation system control. Flexion and extension gaps were measured at full extension and at 90° of flexion using a tensioning device (V-STAT tensor, Zimmer) and a special torque wrench set at 50lb/inch before femoral bone cutting. The flexion and extension gap was evaluated and it’s difference was classified into 3 kinds; balanced, tight flexion gap and tight extension gap. Sixty-one (57.5%) knees were classified as having a ‘balanced gap’ (meaning that flexion and extension gaps were within 2 mm), 20 (18.9%) knees as having a ‘tight flexion gap’ (an extension gap at least 3mm more that the corresponding flexion gap), and 25 (23.6%) knees as having a ‘tight extension gap’ (a flexion gap at least 3mm more that the corresponding extension gap). Depending extension/flexion, and medial/lateral gap difference, the level of distal femoral cut and the rotation of femoral component was determined. Following the final bone cuts and completion of soft tissue release, assessment of the flexion and extension gap was repeated. Balanced flexion and extension gap (difference between flexion and extension gap ≤ 3mm) was confirmed in 99 cases (94%). A mobile bearing prosthesis (e motion FP, B.Braun Aesculap) was used. One patient (bilateral TKAs) died of unrelated causes at postoperative 2 year. One knee was revised due to infection. One hundred three cases were followed up at least more than 4 years, 53 months in average. Overall survival rate is 97%. Average preoperative HHS scores and range of motion (ROM) were 65.4 points (range, 33~82) and 126.8 degrees (80~140). At the last follow-up, HHS score and ROM were 95.0 points (78~100) and 131.4 degrees (110~140). Statistically significant improvement in HHS score and ROM were observed (p<
0.05). The mean mechanical axis was 179.44±1.83° (175~184°) with 8 cases of outliers (more than ±3° of optimum). There was no radiolucency, osteolysis, subsidence, or loosening at the last follow-up. In conclusion, navigation is an excellent predictor for achieving balanced soft tissue &
flexion-extension gap in primary total knee arthroplasty. Navigated TKAs using soft tissue balancing technique showed excellent clinical results and is effective methods achieving accurate mechanical axis and reducing prosthetic alignment outlier.
