Minimally invasive unicompartmental knee replacement with a nonimage-based navigation system (original) (raw)
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The long-term benefit of computer-assisted surgical navigation in unicompartmental knee arthroplasty
2010
We reviewed the outcomes of 30 consecutive primary unicompartmental knee arthroplasties (UKA) performed by a single surgeon for medial compartmental osteoarthritis. Fifteen Allegretto knees were implanted without computer navigation and 15 EIUS knees were implanted with navigation. We compared the survivorship, radiological and clinical outcomes of the two groups at an average of 8.9 years and 6.9 years respectively. The patients were assessed clinically using the Oxford Knee Score (OKS) and radiologically using long-leg weightbearing films and non-weightbearing computed tomography alignment measurements. The overall survivorship was 86.7% at 9 years. A higher proportion of navigated knees were well aligned with a more reproducible position and malaligned knees tended to have a less favourable OKS. However, we found no statistically significant difference in survivorship, clinical outcome and radiological alignment between the two groups.
Knee Surgery, Sports Traumatology, Arthroscopy, 2008
The aim of our study was to compare the use of the Orthopilot Navigation system with conventional nonnavigation technique for medial UKA with respect to the intraoperative mechanical limb alignment measurements and correlation with the postoperative radiological measurements. The postoperative mechanical limb alignment axes of 51 consecutive medial unicompartmental knee arthroplasty performed by a single surgeon over a 12month period were measured. The cases were randomly assigned to two groups of which 21 cases were performed using conventional non-navigation based technique and 30 cases were performed using the Orthopilot Navigation System. Computed tomography (CT) scanogram was performed for all cases within the same hospitalization stay to assess the postoperative mechanical limb alignment. Our results showed that the non-navigated group had a more neutral mechanical axis with a narrower range compared to the navigation assisted group. The difference in the mean mechanical axis between the two groups was statistically not significant. There was poor correlation between the intraoperative navigation system measurements and the postoperative radiological measurements. In conclusion, the use of computer navigation in UKA is not as well validated as compared to TKA. We did not demonstrate any improvement in postoperative axial limb alignment measurement in using a computer navigation system compared to conventional non-navigation technique.
Unicompartmental knee arthroplasty: Is robotic technology more accurate than conventional technique?
The Knee, 2013
Background: Robotic-assisted unicompartmental knee arthroplasty (UKA) with rigid bone fixation "can significantly improve implant placement and leg alignment. The aim of this cadaveric study was to determine whether the use of robotic systems with dynamic bone tracking would provide more accurate UKA implant positioning compared to the conventional manual technique. Methods: Three-dimensional CT-based preoperative plans were created to determine the desired position and orientation for the tibial and femoral components. For each pair of cadaver knees, UKA was performed using traditional instrumentation on the left side and using a haptic robotic system on the right side. Postoperative CT scans were obtained and 3D-to-3D iterative closest point registration was performed. Implant position and orientation were compared to the preoperative plan. Results: Surgical RMS errors for femoral component placement were within 1.9 mm and 3.7°in all directions of the planned implant position for the robotic group, while RMS errors for the manual group were within 5.4 mm and 10.2°. Average RMS errors for tibial component placement were within 1.4 mm and 5.0°in all directions for the robotic group; while, for the manual group, RMS errors were within 5.7 mm and 19.2°. Conclusions: UKA was more precise using a semiactive robotic system with dynamic bone tracking technology compared to the manual technique.
Computerised and technical navigation in total knee-arthroplasty
Journal of Orthopaedics and Traumatology, 2005
The objective of the study was to evaluate the precision, concordance, practicability and the early clinical outcome of the use of a computerised navigation system in a comparative study with a group of 100 patients. Two groups of 50 patients each underwent implantation of a bicondylar knee prosthesis either by means of the freehand navigation system or by means of technical instrumentation. We found that the computerised navigation system provided a higher precision than the technically instrumented implantation: 94% of the prostheses implanted with the navigation system have an alignment within a range of -3° to 3° on of the Mikulicz line. Only 46% of the patients operated by means of the technical instrumentation reached this aspired result. Furthermore, the navigation system showed smaller ranges in the deviation of the aspired alignment. The radiological and computer-modeled alignment values differed both pre- and postoperatively, but to a larger extent before surgery. The varus or valgus deviations of the axis were more distinct radiologically under the weight of the patient’s body than in the computer model. The clinical outcome examined by the use of the HSS score after a mean followup of 7 months is good in both groups, and without significant differences. On average, the duration of surgery was 13 minutes longer in the computerised navigation group. We conclude that the benefit of the computerised navigation system is represented by the high improvement of precision. Achieving early clinical results identical to those in the technical instrumentation group, we expect a reduction of aseptic loosening in the computerised navigation group.
BMC Musculoskeletal Disorders, 2013
Background: There are few Scandinavian studies on the effect of computer assisted orthopedic surgery (CAOS) in total knee arthroplasty (TKA), compared to conventional technique (CON), and there is little information on effects in pain and function scores. This retrospective study has evaluated the effects of CAOS on radiological parameters and pain, function and quality of life after primary TKA. Methods: 198 primary TKAs were operated by one surgeon in two district hospitals; 103 CAOS and 95 CON. The groups were evaluated based on 3 months post-operative radiographs and a questionnaire containing the knee osteoarthritis outcome score (KOOS), the EQ-5D index score and a visual analogue scale (VAS) two years after surgery. Multiple linear regression method was used to investigate possible impact from exposure (CON or CAOS). Results: On hip-knee-ankle radiographs, 20% of measurements were > ±3°of neutral in the CAOS group and 25% in the CON group (p = 0.37). For the femoral component, the number was 5% for CAOS and 18% for CON (p < 0.01). For the tibial component, the difference was not statistically significant (p = 0.58). In the sagittal plane, the surgeon tended to apply more femoral flexion and more posterior tibial slope with CAOS. We observed no statistically or clinically significant difference in KOOS score, VAS or ΔEQ-5D (all p values >0.05), but there was a trend towards better scores for CAOS. Operation time was 3 minutes longer for CON (p = 0.37). Conclusions: CAOS can improve radiological measurements in primary TKA, and makes it possible to adjust component placement to the patient's anatomy. Overall , the two methods are equal in pain, function and quality-of-life scores.
Mechanical accuracy of navigated minimally invasive total knee arthroplasty (MIS TKA)
The Knee, 2009
This study was designed to provide evidence that computer-navigated minimally invasive total knee arthroplasty (MIS CN-TKA) enables identical mechanical accuracy as conventional computer navigated total knee arthroplasty (CN-TKA) while reducing rehabilitation time and hospital stay of the patients. Two groups of 20 patients requiring total knee arthroplasty due to degenerative or posttraumatic knee osteoarthritis were included. Twenty consecutive patients received conventional CN-TKA and 20 consecutive patients received minimally invasive CN-TKA. Mechanical and rotational alignments were measured preoperatively and 6 months postoperatively on long-standing radiographs, on conventional coronal and sagittal views and on CT-scans of the knee. Length of skin incision, operating time, blood loss, length of hospital stay, postoperative ROM and HSS as well as KSS scores were determined. Postoperative mechanical axis improved significantly in both groups. Coronal and sagittal component positioning were accurate in both groups without significant differences. Rotational alignment showed the desired reproducible values without significant differences between the two groups. The posterior slope of the tibial component was significantly reconstructed to match the preoperative condition in both groups. The coronal alignment of the femoral and tibial components showed accurate reproducible results for implantation of both components in both groups. Length of skin incision was significantly shorter in the MIS CN-TKA. Duration of hospital stay was significantly reduced in the MIS CN-TKA group. Operating time and blood loss were similar in both groups. Postoperative ROM after the first 3 months was significantly higher in MIS CN-TKA, but after 6 months differences were minimal. Clinical outcome scores were identical for both groups 6 months after surgery. The advantages of CN-TKA are well known. Performing computer navigated TKA in combination with a minimally invasive approach in this study lead to a reduction of hospital stay and an initially increased ROM without differences in operating time and blood loss. Computer navigation in TKA preserves accurate coronal, sagittal and rotational components alignment even with a minimally invasive approach.
Robot-Assisted Unicompartmental Knee Arthroplasty
The Journal of Arthroplasty, 2010
The outcomes of unicompartmental knee arthroplasties (UKAs) have demonstrated inconsistent long-term survival. We report the first clinical series of UKA using a semiactive robotic system for the implantation of an inlay unicondylar knee arthroplasty. Ten patients were selected for this study. Preoperative mechanical leg alignment values ranged from 0.3°varus to 9.8°varus. A haptic guidance system was used; a detailed description is given in the manuscript. The setup time for the robot was 41 minutes; intraoperative registration process, 7.5 minutes (6-13 minutes); skin incision, 8 cm; robot-assisted burring, 34.8 minutes (18-50 minutes); mean tourniquet time, 87.4 minutes (68-113 minutes); and overall operation time, 132 minutes (118-152 minutes). The planned and intraoperative tibiofemoral angle was within 1°. The postoperative long leg axis radiographs were within 1.6°. Haptic guidance in combination with a navigation module allows for precise planning and execution of both inlay components in UKA. Keywords: robot assisted, uniknee arthroplasty, haptic guidance system, medial osteoarthritis.
Computer navigation and total knee arthroplasty
Orthopedics, 2014
Research has added evidence in favor of computer-navigated techniques over conventional surgery for total knee arthroplasty (TKA). The goal of the current meta-analysis was to compare the outcome of outliers in mechanical axis and postoperative complications in patients undergoing conventional vs computer-navigated techniques for TKA. English literature searches were performed in PubMed, EMBASE, Web of Science, and the Cochrane Library for studies published between January 2002 and August 2012. Randomized, controlled trials comparing computer navigation with conventional surgery for the measurement of mechanical axes in patients with primary osteoarthritis were considered eligible. Fifteen trials were eligible for inclusion. The baseline demographics of 2089 patients (computer-navigated=1111; conventional=978) were well matched. Publication bias was eliminated using the funnel plot. A mechanical axis of more than 30° was considered to be malalignment and an outlier in limb alignment...