Computer Assisted Total Knee Arthroplasty: Does it Make a Difference? (original) (raw)
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MUSCULOSKELETAL SURGERY, 2016
Introduction This retrospective study examined the relationship between the mechanical axis throughout a functional arc of motion and functional outcome scores in patients undergoing computer-assisted navigation-based total knee arthroplasty (CAN-TKA) at 6-year follow-up. Materials and methods The Stryker eNact Precision Knee Navigation System was utilized to obtain pre-and postoperative alignment measurements throughout the functional arc of motion. Patients were contacted via telephone and asked to complete the Short Form-12 and Western Ontario and McMaster Universities, which have been demonstrated to be reliable, valid, and sensitive assessment tools in this patient population. Statistical analysis was performed to determine the correlation between arc alignment and patient-reported functional outcome measures. Results A total of 47 patients at a mean of 76.1 (±6.3)month follow-up and mean age of 65.9 (±7.9) years were surveyed. No correlation was found between the postoperative alignment or degree of intraoperative correction and the functional outcome scores. In a planned subgroup analysis of patients with a mean functional arc alignment greater than 3°from neutral, mean intraoperative degree of correction correlated with decreasing physical function (Spearman's q = 0.772, p = 0.04) and mean postoperative arc alignment positively correlated with increasing stiffness (q = 0.798, p = 0.03). Conclusion This study suggests that patients undergoing CAN-TKA with mean functional arc range of motion greater than 3°may be at increased risk for suboptimal patient-reported functional outcomes. This study also illustrates the ability of CAN-TKA to measure the varus or valgus alignment of the knee throughout the entire range of motion.
BMC Musculoskeletal Disorders
Despite good results of primary total knee arthroplasty (TKA), the number of revision total knee arthroplasties (rTKAs) is rising. Proper implant position is essential, since malposition leads to worse clinical outcome. In rTKA most anatomical landmarks have disappeared because of extensive bone loss, making it more difficult to adequately implant the knee prosthesis. In primary TKA, computer-assisted surgery (CAS) leads to better prosthetic alignment than mechanical navigation guides. Literature about the use of CAS in rTKA is scarce though, and the effect on rotational prosthetic alignment has not been investigated yet. Hence the primary objective of this study is to compare rotational prosthetic alignment when using CAS in rTKA compared to a mechanical navigation guide. Secondary objectives are to compare prosthetic alignment in the coronal and sagittal planes. It is hypothesized that CAS leads to better rotational, coronal and sagittal prosthetic alignment when used during rTKA....
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.
J Bone Joint Surg Am, 2011
BACKGROUND: Optimal alignment of the prosthesis in total knee arthroplasty results in improved patient outcomes. The goal of this study was to determine the most accurate technique for component alignment in total knee arthroplasty by comparing computer-assisted surgery with two conventional techniques involving use of an intramedullary guide for the femur and either an intramedullary or an extramedullary guide for the tibia. METHODS: One hundred and seven patients were randomized prior to surgery to one of three arms: computer-assisted surgery for both the femur and the tibia (the computer-assisted surgery group), intramedullary guides for both the femur and the tibia (the intramedullary guide group), and an intramedullary guide for the femur and an extramedullary guide for the tibia (the extramedullary guide group). Measurements of alignment on hip-to-ankle radiographs and computed tomography (CT) scans made three months after surgery were evaluated. The operative times and complications were compared among the three groups. RESULTS: The coronal tibiofemoral angle demonstrated, on average, less malalignment in the computer-assisted surgery group (1.91°) than in the extramedullary (3.22°) and intramedullary (2.59°) groups (p = 0.007). The coronal tibiofemoral angle was >3° of varus or valgus deviation in 19% (seven) of the thirty-six patients treated with computer-assisted surgery compared with 38% (thirteen) of the thirty-four in the extramedullary guide group and 36% (thirteen) of the thirty-six in the intramedullary guide group (p = 0.022). The increase in accuracy with computer-assisted surgery came at a cost of increased operative time. The operative time for the computer-assisted surgery group averaged 107 minutes compared with eighty-three and eighty minutes, respectively, for the surgery with the extramedullary and intramedullary guides (p < 0.0001). There was no significant difference in any of the outcomes between the intramedullary and extramedullary guide groups. CONCLUSIONS: This study provides evidence that the implant alignment with computer-assisted total knee arthroplasty, as measured with radiography and computed tomography, is significantly improved compared with that associated with conventional surgery with intramedullary or extramedullary guides. This finding adds to the body of evidence showing an improved radiographic outcome with computer-assisted surgery compared with that following conventional total knee arthroplasty.
Total knee arthroplasty with computer-assisted navigation: an analysis of 200 cases
Revista Brasileira de Ortopedia (English Edition), 2014
Objective: to evaluate the results from surgery with computer-assisted navigation in cases of total knee arthroplasty. Method: a total of 196 patients who underwent total knee arthroplasty with computerassisted navigation were evaluated. The extension and flexion spaces (gaps) were evaluated during the operation and the alignment after the operation was assessed. The Knee Society Score (KSS) questionnaire for assessing patient's function was applied preoperatively and postoperatively after a mean follow-up of 22 months. Results: in all, 86.7% of the patients presented good alignment of the mechanical axis (less than 3 • of varus or valgus in relation to the mechanical axis) and 96.4% of the patients presented balanced flexion and extension gaps. Before the operation, 97% of the patients presented poor or insufficient KSS, but after the operation, 77.6% presented good or excellent KSS. Conclusion: the navigation system made it possible to achieve aligned and balanced implants, with notable functional improvement among the patients. It was found to be useful in assessing, understanding and improving knowledge in relation to performing arthroplasty procedures.
The Journal of Arthroplasty, 2009
This is a randomized prospective controlled trial comparing the alignment, function, and patient quality-of-life outcomes between patients undergoing conventional (CONV) and computer-assisted (CAS) knee arthroplasty. One hundred and fifteen patients (60 CAS, 55 CONV) underwent cemented total knee arthroplasty. Three patients were lost to follow-up. Eighty-eight percent (CAS) vs 61% (CONV) of knees achieved a mechanical axis within 3°of neutral (P = .003). Aligning femoral rotation with the epicondylar axis was accurately achieved in CAS and CONV with no significant difference. Patients with coronal alignment within 3°of neutral had superior International Knee Society and Short-Form 12 physical scores at 6 weeks, 3 months, 6 months, and 12 months after surgery. Computer-assisted total knee arthroplasty achieves greater accuracy in implant alignment and this correlates with better knee function and improved quality of life. Key words: computer-assisted surgery, function, patient quality of life, alignment.
The Journal of Arthroplasty, 2012
This retrospective study examined the relationship between the mechanical axis of the knee throughout its functional arc and functional outcomes in patients with computer-assisted navigation total knee arthroplasty. Data on final intraoperative functional arc alignment were obtained on 76 patients who had computer-assisted navigation total knee arthroplasty over a 2-year period and correlated with scores from postoperative Short Form 12 and Western Ontario and McMaster Universities functional outcome surveys. No correlation was found between functional arc alignment and outcomes from Western Ontario and McMaster Universities or Short Form 12 surveys; however, subgroup analysis of patients with more than 3°average final intraoperative alignment throughout the functional arc of motion demonstrated increased difficulty with daily activities (P = .05). The results indicate that patients with more than 3°average alignment throughout the functional arc of motion perform more poorly with daily activities postoperatively. Keywords: total knee arthroplasty, navigated total knee arthroplasty, kinematic curve, functional outcomes, range of motion.
Does computer navigation in total knee arthroplasty improve patient outcome at midterm follow-up?
International …, 2009
Computer navigation assistance in total knee arthroplasty (TKA) results in consistently accurate alignment of prostheses. We aimed to compare the outcome of computer-navigated and conventional TKA and to analyse the radiologically malaligned knees. We analysed 637 primary TKA, carried out by a single surgeon, over five consecutive years and divided them into two cohorts: group 1 = STA (standard instrumentation) and group 2 = CAS (computer-assisted surgery). There was no significant difference between the average Oxford Knee Scores (OKS) of the two groups at any time from one to five years. However, the malaligned TKA at three years had a worse OKS. At medium term there is no difference in clinical outcome measures that can be attributed to the surgeon having used computer-assisted navigation for TKA. But group 1, having a higher proportion of malaligned TKA, might show worsening of OKS at long term.
Computer-Assisted Navigation Software Advancements Improve the Accuracy of Total Knee Arthroplasty
The Journal of Arthroplasty, 2011
The purpose of this study was to evaluate the effectiveness of software advancements in improving total knee component positioning and limb alignment when using computer-aided navigation. A single total joint fellowship-trained surgeon performed unilateral total knee arthroplasty on 315 patients using conventional techniques or with assistance from computer navigation software. Preoperative and postoperative x-ray measurements were taken and analyzed. Our previous work demonstrated a statistically significant improvement (P b .02) in limb alignment (±3°of biomechanical neutral) when using version 2.0 software (93%) when compared with conventional techniques (82%). Further improvement was demonstrated with the version 3.1 software (99%, P b .03). The tourniquet times were recorded for each group and showed a significant improvement with the 3.1 software (conventional = 74 minutes, 2.0 navigation = 90 minutes, and 3.1 navigation = 73 minutes). The Stryker 2.0 software (Stryker Orthopedics, Mahwah, NJ) tourniquet time was statistically significantly longer than either the conventional or the 3.1 group (P b .001). Outcomes-based studies will be required to see if these factors will lead to improved patient function and/or prolonged prosthetic survival rates.
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...