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Computer-Assisted Technologies in Arthroplasty: Navigating Your Way Today
Abstract
» Computer-assisted technologies that are used in arthroplasty include navigation, image-derived instrumentation (IDI), and robotics.
» Computer-assisted navigation improves accuracy and allows for real-time assessment of component positioning and soft-tissue tension.
» It is not clear whether the implementation of these technologies improves the clinical outcome of surgery.
» High cost and time demands have prevented the global implementation of computer-assisted technologies.
Supplementary resource (1)
Data
March 2020
... However some disadvantages are cited related to the use of robot like longer surgical time; learning curve, costs; dubious results regarding to function and patient satisfaction; and surgery durability [15]. ...
... Other advantage could be the lesser amount of trays and instruments to perform the surgery, reducing logistics and sterilization costs [4,6,15]. ...
Despite the evolution in implant design, surgical technique, rehabilitation and better medical training, a great number of patients are not satisfied with the final result of Total Knee Arthroplasty (TKA). The conventional TKA technique could result in a high number of outliers in limb alignment and are related to a high rate of residual symptoms. Robotically assisted (RA) surgery was introduced to improve these results. Recent studies showed this technique is associated to lower costs, better accuracy in implant placement and limb alignment, improvement in function and patient satisfaction. RA technique is also related to less blood loss, less bone resection and smaller aggression to soft tissues. Besides that, this brings better ergonomics to the surgeon with less caloric waste. In this way, by the benefits showed, the adhesion to the robotic surgery must be encouraged.
... Technology-assisted arthroplasty, which includes computerassisted navigation (CAN) and robotic assistance (RA), has been available since the 1990s for total knee arthroplasty (TKA) [1,2]. Adoption of technology assistance for TKA has varied globally; over one-third of all arthroplasties performed in Australia use CAN, while fewer than one percent of arthroplasties performed in Sweden are technology-assisted [1]. ...
... Technology-assisted arthroplasty, which includes computerassisted navigation (CAN) and robotic assistance (RA), has been available since the 1990s for total knee arthroplasty (TKA) [1,2]. Adoption of technology assistance for TKA has varied globally; over one-third of all arthroplasties performed in Australia use CAN, while fewer than one percent of arthroplasties performed in Sweden are technology-assisted [1]. ...
Background
Computer-assisted navigation (CAN) and robotic assistance (RA) for total knee arthroplasty (TKA) are gaining in popularity. The purpose of this study is to update the literature on United States technology-assisted TKA trends of national utilization, regional utilization, and 90-day complication rates requiring readmission.
Methods
Patients who underwent primary, elective TKA between 2010 and 2018 were retrospectively identified in the PearlDiver All Payer Claims Database (PearlDiver Technologies Inc.). TKAs were classified as conventional, CAN, or RA based on International Classification of Diseases nineth or tenth revision and Current Procedural Technology codes. Annual rates and regional trends of each type of TKA were reported. Ninety-day complications requiring readmission for each group were captured. Multivariable logistic regression was used to identify odds ratios (OR) for all-cause readmission based on TKA modality.
Results
Of the 1,307,411 elective TKAs performed from 2010 to 2018, 92.8% were conventional, and 7.7% were technology-assisted (95.2% CAN and 4.9% RA). RA-TKA had the greatest increase in utilization (+2204%). The Western region had the highest utilization of technologies for TKA, while the Midwestern region had the lowest. Ninety-day postoperative complications requiring readmission were highest for conventional TKA and lowest for RA-TKA. RA-TKA (OR 0.68; 97.5% confidence interval 0.56-0.83, P < .001) and CAN-TKA (OR 0.93; 97.5% confidence interval 0.88-0.97, P < .05) had significantly lower odds of all-cause 90-day complications requiring readmission than conventional TKA.
Conclusion
Utilization of RA-TKA and CAN-TKA continues to rise across the United States. The use of these technologies is associated with a lower OR of readmission within 90 days postoperatively.
... There has been an increase in the use of assistive technology such as navigation and, more recently, robotics [10]. In 2021, 28.5% of TKR performed in Australia were using navigation, and 22.5% used robotics [1]. ...
Purpose:
The decision on which technique to perform a total knee arthroplasty (TKA) has become more complicated over the last decade. Perceived limitations of mechanical alignment (MA) and kinematic alignment (KA) have led to the development of the functional alignment (FA) philosophy. This study aims to report the 2-year results of an initial patient cohort in terms of revision rate, PROMs and complications for Computer Aided Surgery (CAS) Navigated FA TKA.
Methods:
This paper reports a single surgeon's outcomes of 165 consecutive CAS FA TKAs. The final follow-up was 24 months. Pre-operative and post-operative patient-reported outcome measures, WOMAC and KSS, and intra-operative CAS data, including alignment, kinematic curves, and gaps, are reported. Stress kinematic curves were analysed for correlation with CAS final alignment and CAS final alignment with radiographic long-leg alignment. Pre- and post-operative CPAK and knee phenotypes were recorded. Three different types of prostheses from two manufacturers were used, and outcomes were compared. Soft tissue releases, revision and complication data are also reported.
Results:
Mean pre-operative WOMAC was 48.8 and 1.2 at the time of the final follow-up. KSS was 48.8 and 93.7, respectively. Pre- and post-operative range of motion was 118.6° and 120.1°, respectively. Pre-operative and final kinematic curve prediction had an accuracy of 91.8%. CAS data pre-operative stress alignment and final alignment strongly correlate in extension and flexion, r = 0.926 and 0.856, p < 0.001. No statistical outcome difference was detected between the types of prostheses. 14.5% of patients required soft tissue release, with the lateral release (50%) and posterior capsule (29%) being the most common.
Conclusion:
CAS FA TKA in this cohort proved to be a predictable, reliable, and reproducible technique with acceptable short-term revision rates and high PROMs. FA can account for extremes in individual patient bony morphology and achieve desired gap and kinematic targets with soft tissue releases required in only 14.5% of patients.
Level of evidence:
IV (retrospective case series review).
... Therefore, the transition from one systematic standard alignment workflow to one of the existing individual workflows needs guidance and education. In addition, this transition in the OR is time-consuming and increases surgeon stress levels and consequent surgical errors [21]. It is likely that the increased complexity of computer-assisted surgery (CAS) is one of the main reasons why it gained only limited acceptance in the orthopaedic surgeon community [22][23][24][25][26][27]. ...
Individual alignment techniques have been introduced to restore patients’ unique anatomical variations during total knee arthroplasty. The transition from conventional mechanical alignment to individualised approaches, with the assistance of computer and/or robotic technologies, is challenging. The objective of this study was to develop a digital training platform with real patient data to educate and simulate various modern alignment philosophies. The aim was to evaluate the training effect of the tool by measuring the process quality and efficiency, as well as the post-training surgeon’s confidence with new alignment philosophies. Based on 1000 data sets, a web-based interactive TKA computer navigation simulator (Knee-CAT) was developed. Quantitative decisions on bone cuts were linked to the extension and flexion gap values. Eleven different alignment workflows were introduced. A fully automatic evaluation system for each workflow, with a comparison function for all workflows, was implemented to increase the learning effect. The results of 40 surgeons with different experience levels using the platform were assessed. Initial data were analysed regarding process quality and efficiency and compared after two training courses. Process quality measured by the percentage of correct decisions was increased by the two training courses from 45% to 87.5%. The main reasons for failure were wrong decisions on the joint line, tibia slope, femoral rotation, and gap balancing. Efficiency was obtained with a reduction in time spent per exercise from 4 min 28 sec to 2 min 35 sec (42%) after the training courses. All volunteers rated the training tool as helpful or extremely helpful for learning new alignment philosophies. Separating the learning experience from OR performance was mentioned as one of the main advantages. A novel digital simulation tool for the case-based learning of various alignment philosophies in TKA surgery was developed and introduced. The simulation tool, together with the training courses, improved surgeon confidence and their ability to learn new alignment techniques in a stress-free out-of-theatre environment and to become more time efficient in making correct alignment decisions.
... amounts of femoral anteversion, changeable neck or cone-type stems may be useful options, by adjusting femoral anteversion to achieve the target CA (Matsushita et al., 2010;Howie et al., 2012). Computerassisted surgeries such as navigation or robot-assisted systems have been reported as useful tools to verify and achieve the precise orientation of components (Hazratwala et al., 2020;Rhee et al., 2019). The present study has several limitations. ...
Objectives: The study aimed to elucidate target cup orientation and stem anteversions to avoid impingement between the liner and stem neck even at hip rotation with adduction during the deeply flexed posture.
Methods: A computer simulation analysis was performed on 32 total hip arthroplasty patients applying patient-specific orientation of the components and in vivo hip kinematics obtained from three-dimensional analysis of the squatting motion. The anterior/posterior liner-to-neck distance and impingement were evaluated based on a virtual change in internal/external rotation (0°–60°) and adduction/abduction (0°–20°) at actual maximum flexion/extension during squatting. Cutoff values of cup orientations, stem anteversion, and combined anteversion to avoid liner-to-neck impingements were determined.
Results: The anterior liner-to-neck distance decreased as internal rotation or adduction increased, and the posterior liner-to-neck distance decreased as external rotation or adduction increased. Negative correlations were found between anterior/posterior liner-to-neck distances at maximum flexion/extension and internal/external rotation. Anterior/posterior liner-to-neck impingements were observed in 6/18 hips (18/56%) at 45° internal/external rotation with 20° adduction. The range of target cup anteversion, stem anteversion, and combined anteversion to avoid both anterior and posterior liner-to-neck impingements during squatting were 15°–18°, 19°–34°, and 41°–56°, respectively.
Conclusion: Simulated hip rotations caused prosthetic impingement during squatting. Surgeons could gain valuable insights into target cup orientations and stem anteversion based on postoperative simulations during the deeply flexed posture.
Understanding alignment and gap balancing in Total Knee Arthroplasty (TKA) can be challenging for trainee and experienced orthopedic surgeons. Traditional learning methods may not effectively translate to real-life scenarios. The advent of advanced technologies like robotic surgery and navigation systems has revolutionized intraoperative understanding of gap balancing techniques. This trial aims to investigate the effectiveness of robotic TKA planning software in educating trainees about alignment and ligament balancing. We hypothesize that a single session with the software will significantly enhance trainees’ understanding of these techniques. This UK-based single-center, two-arm, group parallel randomized controlled trial was conducted during a national robotic arthroplasty symposium. It aims to evaluate the effect of robotic knee arthroplasty software training on understanding TKA alignment and gap balancing principles using Multiple Choice Questions (MCQs). The MCQ test was crafted based on established guidelines from a different institution with expert consensus in the field. Our study revealed that baseline knowledge of gap balancing and alignment principles was generally low among all participants. However, the intervention group, which received comprehensive robotic software training, demonstrated a significant improvement in their MCQ scores compared to the control group, which did not undergo the training. In conclusion, our study demonstrates that robotic arthroplasty software training significantly improves the understanding of TKA alignment and balancing principles among orthopedic trainees. Level of Evidence II.
Background:
The use of technology during total knee arthroplasty (TKA)-specifically computer navigation (CN) and robotic assistance (RA)-has been associated with more accurate component position and less blood loss. Yet to date, the risk of developing prosthetic joint infection (PJI) associated with technology use has not been thoroughly evaluated. This study used propensity score matching (PSM) in a large cohort of primary TKA patients to compare the rate of PJI following conventional TKA (TKA) versus CN-TKA and RA-TKA.
Methods:
We retrospectively reviewed 13,015 knees in 11,727 patients who underwent primary TKA at a single institution from 2018-2021. The cohort was stratified into TKA, CN-TKA, and RA-TKA groups. 1:1 PSM was applied to 11,834 patients. PSM was performed using logistic regression accounting for age, sex, body mass index, Charlson Comorbidity Index (CCI) score, CCI components, and smoking status to isolate the effect of technology on PJI risk. Univariate and multivariable analyses were performed to evaluate differences in surgical time and PJI rate.
Results:
Significantly median longer operating times were noted in the RA-TKA group (14 minutes) compared to TKA (P<0.001). The PJI rates among matched cohorts were similar among RA-TKA (0.3%), CN-TKA (0.3%), and conventional TKA (0.5%). Multivariable logistic regressions demonstrated that the use of robotic-assistance (Odds ratio (OR)=0.5, P=0.423) or computer-navigation (OR=0.61, P=0.128) was not associated with increased risk of PJI when compared to conventional TKA.
Conclusion:
Use of computer navigation and robotic assistance during primary TKA are associated with longer surgical times, but no difference in PJI frequency within 90 days of surgery.
Technological innovation in total hip arthroplasty (THA) is a critical component of health care delivery for improving patient outcomes. Analyzing the content of patents and trends in their activity over time can leverage insight into innovations in THA; however, these investigations remain underutilized. We aimed to quantify patent activity and relative growth pertaining to technologies in THA over a 30-year period. A query for patents relating to “hip replacement” or “hip arthroplasty” between 1989 and 2019 using an open-source patent database yielded 24,071 unique patents for analysis. These were grouped into 12 independent technology clusters using Cooperative Patent Classification codes. Annual patent activity for each cluster was normalized with a validated formula to control for exponential growth. The 5-, 10-, and 30-year compound annual growth rates (CAGR) for each cluster were quantified and compared between clusters. Annual cumulative patent activity increased from 151 patents in 1989 to 1,182 patents in 2019, representing a 682.8% increase. The largest technology clusters concerned “drugs” (n = 6,429 patents), “instruments” (n = 4,014 patents), “materials” (n = 2,037 patents), and “components” (n = 1,946 patents). One-half of the identified clusters concerned developments in technology-assisted THA (patient-specific instrumentation, navigation, robotics, design/manufacturing, instruments, and computer modeling). The most rapidly growing technology within the past 5, 10, and 30 years was robotics (CAGR = 15.82%, 20.11%, and 9.50%, respectively). Within the past 5- and 10-year trial prostheses (CAGR = 10.76%) and design/manufacturing processes (CAGR = 10.27%), computer modeling (CAGR = 12.91%) and navigation (CAGR = 11.25%) were among the most rapidly growing clusters, respectively. The majority of patents pertaining to THA over the past 30 years have concerned developments in drugs, instruments, materials, and components. Within the past 10-years, substantial growth has been observed in patent domains related to technology-assisted THA. Monitoring of emerging technologies through patent metrics may provide valuable information for regulatory bodies and assess progress in the field of THA. This is a cross-sectional study with level of evidence IV.
Purpose:
Computer-assisted arthroplasty supports the surgeons in planning, simulating, and performing the replacement procedure, using robotic or navigation technologies. However, the safety of the technology has not been widely ascertained. Food and Drug Administration (FDA) database was interrogated about software-related recalls in computer-assisted arthroplasty, aiming to assess: (1) the incidence, (2) the root causes, and (3) the actions taken due to recalls.
Methods:
The Medical Device Recalls database was investigated about software-related recalls in computer-assisted hip and knee arthroplasty surgery, between 2017 and 2022. The incidence of the software-related recalls, the root causes according to FDA and manufacturers, and the corrective actions taken by firms were determined.
Results:
Eighteen recall numbers could be identified (1.6%), corresponding to 11 recall events. A total of 4634 units were involved. The FDA determined root causes were: software design (66.6%), design change (22.2%), manufacturing deployment (1, 5.6%), and design manufacturing process (5.6%). Among the manufacturers' reasons for recalls, a specific error was declared in 16 cases (88.9%). In seven cases (43.8%), a coding error about lower limb alignment assessment was identified. Seventeen software-related recalls (94.4%) were classified as class 2; only one case was class 3 (5.6%). Return of the device was the main action taken by firms (8, 44.4%), followed by software update (7, 38.9%).
Conclusion:
Software-related recalls in computer-assisted hip and knee arthroplasty were quite uncommon among all the recalls, deemed non-life threatening and usually due to software design errors. The main actions taken by manufacturers were the return of the device or the software update.
Study design:
Retrospective National Database Study.
Objectives:
The purpose of this study is to evaluate the cost and patient outcomes associated with the utilization of computer-assisted navigation (CAN) utilization on patients undergoing lumbar spinal fusion.
Background:
CAN systems have demonstrated comparable outcomes with instrumentation and procedural speed when compared with traditional techniques. In recent years, CAN systems have seen increased adoption in spinal surgery as they allow for better contextualization of anatomical structures with the goal of improving surgical accuracy and reproducibility.
Methods:
The 2016 National Readmission Database was queried for patients with lumbar spinal fusion ICD-10 codes, with 2 subgroups created based on computer-aided navigation ICD-10 codes. Nonelective cases and patients below 18 years of age were excluded. Univariate analysis on demographics, surgical data, and total charges was performed. Postoperative complication rates were calculated based on diagnosis. Lastly, multivariate analysis was performed to assess navigation's impact on cost and postoperative outcomes.
Results:
A total of 88,445 lumbar fusion surgery patients were identified. Of the total, 2478 (2.8%) patients underwent lumbar fusion with navigation utilization, while 85,967 (97.2%) patients underwent surgery without navigation. The average total charges were 150,058, 161,018 (155,747, 166,289) for the non-CAN and CAN groups, respectively (P<0.001). The 30-day readmission rates were 5.3% for the non-CAN cohort and 3.1% for the CAN cohort (P<0.05). The 90-day readmission rates were 8.8% for the non-CAN cohort and 5.2% for the CAN cohort (P<0.001).
Conclusions:
CAN use was found to be significantly associated with increased cost and decreased 30-day and 90-day readmissions. Although patients operated on with CAN had increased routine discharge and decreased readmission risk, future studies must continue to evaluate the cost-benefit of CAN. Limitations include ICD-10 codes for CAN utilization being specific to region of surgery, not to exact type.
Level of evidence:
Level III.
Study design:
Retrospective cohort study of 2016 Healthcare Cost and Utilization Project Nationwide Readmissions Database (NRD).
Objective:
The aim was to evaluate cost and outcomes associated with navigation use on posterior cervical fusion (PCF) surgery patients.
Summary of background data:
Computer-assisted navigation systems demonstrate comparable outcomes with hardware placement and procedural speed compared with traditional techniques. Innovations in technology continue to improve surgeons' performance in complicated procedures, causing need to analyze the impact on patient care.
Methods:
The 2016 NRD was queried for patients with PCF surgery ICD-10 codes. Cost and readmission rates were compared with and without navigation. Nonelective cases and patients below 18 years of age were excluded. Univariate analysis on demographics, surgical data, and total charges was performed. Lastly, multivariate analysis was performed to assess navigation's impact on cost and postoperative outcomes.
Results:
A total of 11,834 patients were identified, with 137 (1.2%) patients undergoing surgery with navigation and 11,697 (98.8%) patients without. Average total charge was 141,270.1 for the non-navigation and navigation cohorts, respectively (P=0.349). Thirty-day and 90-day readmission rates were not significantly lower in patients who received navigation versus those that did not (P=0.087). This remained insignificant after adjusting for several variables, age above 65, sex, medicare status, mental health history, and comorbidities. The model adjusting for demographic and comorbidities maintained insignificant results of navigation being associated with decreased 30-day and 90-day readmissions (P=0.079).
Conclusions:
Navigation use in PCF surgery was not associated with increased cost, and patients operated on with navigation did not significantly have increased routine discharge or decreased 90-day readmission. As a result, future studies must continue to evaluate the cost-benefit of navigation use for cervical fusion surgery.
Level of evidence:
Level III.
Background
Dislocation after total hip arthroplasty is a frequent cause of revision surgery. This study was performed to determine the optimal implant alignment in total hip arthroplasty by simulating the postoperative range of motion.
Methods
All operations were performed via posterolateral approach using combined anteversion of the stem and cup technique. Maximum range of motion without implant impingement was simulated in 79 replaced hips using postoperative computed tomography and the achievement of the required range of motion defined by previous studies was assessed. Optimal cup and stem alignment for impingement-free range of motion were statistically determined using the receiver operator coefficient curve.
Findings
Cup inclination and anteversion, stem anteversion, and combined anteversion were 37.6°, 20.1°, 26.2°, and 46.3°, respectively. Maximum range of motion in flexion, extension, internal rotation at 90° of flexion, and external rotation were 131.8°, 42.3°, 56.4°, and 64.5°, respectively. Flexion >110°, extension >30°, internal rotation >30° at 90° of flexion, and external rotation >30° were fulfilled by 96%, 86%, 92%, and 96% of all replaced hips, respectively. Optimal implant alignment for impingement-free range of motion was 34°–43° of cup inclination, 18°–26° of cup anteversion, 17°–29° of stem anteversion, and 35°–56° of combined anteversion. Both cup and stem anteversion showed significant relationship with postoperative range of motion.
Interpretation
Surgeons could gain valuable insights into optimal cup and stem alignment to perform postoperative range of motion simulations.
Malalignment of total knee arthroplasty (TKA) components affects function and survivorship. Common practice is to set coronal alignment prior to adjusting slope. With improper jig placement, adjustment of the slope may alter coronal alignment. The purpose of this study was to quantify the change in coronal alignment with increasing posterior tibial slope while comparing two methods of jig fixation. A prospective consecutive series of 100 patients underwent TKA using computer navigation. Fifty patients had the extramedullary cutting jig secured proximally with one pin and 50 patients had the jig secured proximally with two pins. Coronal alignment (CA) was recorded with each increasing degree of posterior slope (PS) from 0 to 7 degrees. Mean CA and change in CA were compared between cohorts. Utilizing one pin, osteotomies drifted into varus with an average change in CA of 0.34 degrees per degree PS. At 4 degrees PS, patients started to have >3 degrees of varus with 12.0% having >3 degrees of varus at 7 degrees PS. Utilizing two pins, osteotomies drifted into valgus with an average change of 0.04 degrees in CA per degree PS. No patients in the two-pin cohort fell outside 3 degrees varus/valgus CA. CA was significantly different at all degrees of PS between the cohorts. Changes in PS influenced CA making verification of tibial cut intraoperative critical. Use of >1 pin and computer navigation were beneficial to prevent coronal plane malalignment. This relationship may explain why computer navigation has been shown to improve alignment as well as survivorship and outcomes in some patients, especially those <65 years.
Background
Computer navigation and robotic assistance technologies are used to improve the accuracy of component positioning in total knee arthroplasty (TKA), with the goal of improving function and optimizing implant longevity. The purpose of this study was to analyze trends in the use of technology-assisted TKA, identify factors associated with the use of these technologies, and describe potential drivers of cost.
Methods
The Nationwide Inpatient Sample database was used to identify patients who underwent TKA using conventional instrumentation, computer navigation, and robot-assisted techniques between 2005 and 2014. Variables analyzed include patient demographics, hospital and payer types, and hospital charges. Descriptive statistics were used to describe trends. Univariate and multivariate analyses were performed to identify differences between conventional and technology-assisted groups.
Results
Our analysis identified 6,060,901 patients who underwent TKA from 2005 to 2014, of which 273,922 (4.5%) used computer navigation and 24,084 (0.4%) used robotic assistance. The proportion of technology-assisted TKAs steadily increased over the study period, from 1.2% in 2005 to 7.0% in 2014. Computer navigation increased in use from 1.2% in 2005 to 6.3% in 2014. Computer navigation was more likely to be used in the Western United States, whereas robot-assisted TKAs were more likely to be performed in the Northeast. Increased hospital charges were associated with the use of technology assistance (47,639.2).
Conclusions
The use of computer navigation and robot-assisted TKA steadily increased over the study period, accounting for 7.0% of TKAs performed in the United States in 2014. Marked regional differences in the use of these technologies were identified. The use of these technologies was associated with increased hospital charges.
Introduction
Over the past decades many innovations were introduced in total knee arthroplasty (TKA) focusing on implant longevity and higher procedural precision; however, there are still a high number of dissatisfied patients. It was reported that better anatomical alignment may result in improved patient outcome; however, current technologies have limitations to achieve this. The aim of this video article is to describe the technique of individualized alignment in TKA with the use of image-based robotic assistance.
Methods
The technology is based on an individual patient knee model computed from segmented computed tomography (CT) scans. A preoperative planning of prosthesis position is conducted following the principle of kinematic alignment. Intraoperatively the soft tissue envelope is recorded and the computer predicts the gap balance based on the virtual planning. The prosthesis position is then adapted to achieve balanced gaps and to avoid soft tissue release. This technique is shown in a cadaver operation and clinical examples of two patients are described.
Results
With the combination of anatomically oriented prosthesis positioning and minor adaptations with respect to the soft tissue, an individualized alignment is achieved with reduced need of soft tissue release. The robotic-assisted surgery guarantees a precise implementation of the planning. The initial experience showed a promising outcome in short-term follow-up.
Equalization of biomechanical differences is a major goal in total hip arthroplasty (THA). In the current study we compared the accuracy of restoring leg length and offset using imageless navigation with an osseous fixed pin to a femoral pinless device in 97 minimally invasive THAs through an anterolateral approach in the lateral decubitus position. Leg length and offset differences were evaluated on magnification-corrected radiographs by a blinded observer. A postoperative mean difference of -0.9 mm (95% CI -2.8 mm to 1.1 mm, p = 0.38) between pinless navigation and navigation with a fixed pin was observed for leg length and that of -2.4 mm (95% CI -3.9 mm to -0.9 mm, p = 0.002) was observed for offset, respectively. The number of patients with a residual difference below 5 mm after THA was higher if using a fixed pin than in pinless navigation for both leg length (98.2%, 54/55 to 50.0%, 21/42, p < 0.001) and offset (100.0%, 55/55 to 71.4%, 30/42, p < 0.001). Imageless navigation is a feasible method in intraoperative control of leg length and offset in minimally invasive THA. The use of pins fixed to the bone has a higher precision than pinless devices. This trial is registered with DRKS00000739 .
Background Previously published studies reported benefits of computer-assisted surgery (CAS) in terms of radiographic implant position in TKA, but whether these improvements result in clinically important survival differences or functional differences that a patient might perceive at a minimum 10-year followup remains largely unknown.
Questions/purposes We performed a prospective randomized trial and asked whether CAS (1) improved survival free from aseptic loosening; and (2) demonstrated any clear difference in patient-reported outcomes at latest followup using validated outcome measures at minimum 10-year followup.
Methods Between January 2004 and December 2005, 80 patients scheduled for TKA were randomly assigned either to the CAS group or to the conventional technique group by the Hospital Informatics Department. The patient inclusion criteria were age 20 to 80 years old, weight < 100 kg, and consent to receive a primary knee arthroplasty performed through a medial parapatellar approach by the senior author. The exclusion criteria were a history of prior knee surgery, TKA performed for a posttraumatic indication, or revision knee surgery. The first 80 patients meeting these criteria were included in the study. There were 21 women and 19 men and in each group; mean age was 66 years (range, 58-77 years), and mean body mass index was 27 ± 4 kg/m2. An initial published study using this patient group investigated only differences regarding implant positioning in the coronal and sagittal planes. This is a secondary analysis of patients from the earlier study protocol at a minimum of 10-year followup with different endpoints. Kaplan-Meier survivorship was compared between groups, and functional patient-reported outcome measures (PROMs) were evaluated using the SF-12, Knee Injury and Osteoarthritis Outcome Score (KOOS), Forgotten Joint Score, and the new Knee Society Score. Those PROMs were not available at the time of the original randomized controlled trial and we therefore do not have baseline preoperative values demonstrating that our two groups were comparable. However, our groups were created using strict randomization and were similar in terms of demographic parameters and knee deformities. Our secondary analysis was not powered for survival analysis but had 80% power to detect a difference > 6 points on the SF-12 components and > 6 points out of 100 on the KOOS subscores (published minimal clinically important difference: 8 points) at the p < 0.05 level.
Results With the numbers available, there was no difference between the CAS group and the conventional TKA group in terms of survivorship free from aseptic loosening 10 years after TKA (97%, 95% confidence interval [CI], 95%-99% versus 97%, 95% CI, 95%-99%; p = 0.98). Investigation of the latest followup PROM scores showed no difference between SF-12 scores (respectively, for CAS and control patients, physical SF-12: 72 ± 12 versus 73 ± 13 mean difference 0, 95% CI -3 to 3, p = 0.9; mental SF-12: 75 ± 8 versus 73 ± 10, mean difference 2, 95% CI 0−4, p = 0.3) as well as for all KOOS subscores (all p > 0.1). Forgotten Joint Scores were similar in both groups with 83 ± 4 for CAS and 82 ± 5 for control patients (mean difference 1, 95% CI 0−2, p = 0.2). Finally, the new Knee Society Scores were not statistically different between groups with a mean objective score of 82 ± 13 for CAS patients versus 79 ± 12 for control patients (mean difference 2, 95% CI 0−5, p = 0.5) and a mean subjective score of 83 ± 11 versus 85 ± 12, respectively (mean difference 2, 95% CI 0−5, p = 0.5).
Conclusions Our observations suggest that CAS used for TKA alignment with restoration of a neutral mechanical axis as the goal did not confer any substantial advantage in survivorship, function, or quality of life at 10 years after TKA. Larger studies with longitudinal collection of PROMs for functional assessment and greater numbers to assess survivorship are needed to confirm these findings.
Level of Evidence: Level III, therapeutic study.
Computer-assisted navigation was introduced as an adjunct to total knee arthroplasty (TKA) with the potential of improving positioning and alignment of TKA implants. Computer-assisted surgery (CAS) can be divided into: passive (navigated TKA) or semiactive and active (robotic TKA). Passive CAS has shown improved results regarding alignment in TKA compared with conventional instrumentation but it has several possible complications such as registration errors, pin site complications, increased surgical time and a potentially longer learning curve. Robotic TKA has been developed to eliminate the possible error in the preparation of bone surfaces by the surgeon. There is still little evidence on these systems but the early results are encouraging. Despite better results in accuracy with both CAS systems, clinical benefits are still subject of debate. Additional research is required to fully define the costs and benefits of robotics in regular medical practice.
- Mechanical or anatomical alignment techniques create a
supposedly ‘biomechanically friendly’ but often functionally
limited prosthetic knee.
- Alternative techniques for alignment in total knee arthroplasty
(TKA) aim at being more anatomical and patientspecific,
aiming to improve functional outcomes after TKA.
- The kinematic alignment (KA) technique for TKA has
shown good early clinical outcomes. Its role in extreme
anatomical variation remains to be defined.
- The restricted KA technique for TKA might be a reasonable
option for patients with extreme anatomical variation.
- While unicompartmental knee arthroplasty (UKA) has
many advantages over TKA, the revision rate remains
higher compared with TKA. One major explanation is the
relative ease with which a UKA can be converted to a TKA,
compared with revising a TKA. This can be considered as
an additional advantage of UKA. Another reason is that
surgeons favour revising a UKA to a TKA in cases of degeneration
of the other femorotibial compartment rather than
performing a relatively simple re-operation of the knee by
doing an additional UKA (staged bi-UKA).
Purpose
The purpose of this study was to examine the accuracy of implant orientation and leg length in total hip arthroplasty (THA) with an image-free navigation system based on a comparison of the intraoperative navigation and postoperative CT evaluations.
Material and Methods
A consecutive series of 111 patients (118 hips) who underwent THA using the current version of the image-free navigation system constituted the basic study population. Subsequently, a total of 101 patients (108 hips) meeting the inclusion and exclusion criteria were selected as study subjects for the analysis. THA was performed using an image-free navigation system that was capable of adjusting both the prosthetic position and leg length. Postoperative CT examination was performed for all study subjects, and the prosthetic position and leg length were measured on CT images using the image analysis software. Subsequently, the intraoperative navigation results and the corresponding values obtained from the postoperative CT measurements were compared to test the accuracy of the navigation system.
Results
The average discrepancies between the intra- and postoperative assessments were 6.8°, 3.7°, and 5.7° for cup anteversion, cup inclination, and stem anteversion, respectively. The corresponding value in leg length averaged 4.1 mm.
Conclusion
Average discrepancies between the intra- and postoperative measurements were less than 10° in all prosthetic alignment parameters and less than 5 mm in leg length. Intraoperative assessments with the use of the image-free navigation in THA could afford satisfactory result.
Introduction:
Computer assisted surgery was pioneered in early 1990s. The first computer assisted surgery (CAS) total knee replacement with an imageless system was carried out in 1997. In the past 25 years, CAS has progressed from experimental in vitro studies to established in vivo surgical procedures.
Methods:
A comprehensive body of evidence establishing the advantages of computer assisted surgery in knee and hip arthroplasty is available. Established benefits have been demonstrated including its role as an excellent research tool. Its advantages include dynamic pre-operative and per-operative assessment, increased accuracy in correction of deformities, kinematics and mechanical axis, a better alignment of components, better survival rates of prostheses and a better functional outcome. Adoption of computer navigation in the hip arthroplasty is still at an early stage compared to knee arthroplasty, though the results are well documented. Evidence suggests improved accuracy in acetabular orientation, positioning, hip offset and leg length correction.
Results:
Among the orthopaedic surgeons, navigated knee arthroplasty is gaining popularity though slowly. The uptake rates vary from country to country. The Australian joint registry data shows increased navigated knee arthroplasty from 2.4% in 2003 to 28.6% in 2015 and decreased revision rates with navigated knee arthroplasty in comparison with traditional instrumented knee arthroplasty in patient cohort under the age of 55 years.
Conclusion:
Any new technology has a learning curve and with practice the navigation assisted knee and hip arthroplasty becomes easy. We have actively followed the evidence of CAS in orthopaedics and have successfully adopted it in our routine practice over the last decades. Despite the cautious inertia of orthopaedic surgeons to embrace CAS more readily; we are certain that computer technology has a pivotal role in lower limb arthroplasty. It will evolve to become a standard practice in the future in various forms like navigation or robotics.
Computer-aided surgery (CAS) is now nearly 30 years old. It has brought to surgery a variety of tools, techniques, and paradigm changes that have had an impact on how surgeries are planned, executed, and evaluated. In this review, we examine the predictive, preventive, and personalized medicine (PPPM) aspects of CAS. We present a brief history of CAS, summarize its the state of the art, and discuss current trends and future developments related to PPPM. Of the three Ps, we note that the most important impact of CAS is on Personalization, in all the steps of the surgical treatment: preoperative planning, intraoperative execution, and postoperative evaluation. Prediction in CAS is reflected in the preoperative evaluation of the various surgical options and in the evaluation of the possible surgical outcomes. Prevention in CAS is related to intraoperative execution, to help prevent possible surgical complications. We foresee that CAS will play an increasingly important role in PPPM in the coming years.
Modern total knee arthroplasty is effective at treating the pain and disability associated with osteoarthritis. The number of total knee replacements done in the USA continues to increase. Despite the great care taken during all of these procedures, some patients remain dissatisfied with their outcome. While this dissatisfaction is likely multifactorial, malalignment of the prosthetic components is a major cause of postoperative complications. A neutral mechanical axis plus or minus 3° is felt to have a positive impact on the survivorship of the prosthesis. Conventional instrumentation has been shown to have a significant number of total knee replacements that lie well outside a neutral coronal alignment. With that in mind, significant effort has been placed into the development of technology to improve the overall alignment of the prosthesis. In order to reduce the number of outliers, several companies have developed cost-effective systems to aid the surgeon in achieving a more predictably aligned prosthesis in all three planes. We will review the literature that is available regarding several of these tools to examine if navigation or custom guides improve outcomes in total knee arthroplasty. Our review supports that while both navigation and custom implants guides seem to be a cost effective way to achieve a predictable mechanical alignment of a total knee prosthesis therefore reducing the number of outliers, the cost may be increased operative times with no perceived difference in patient satisfaction with navigation custom guides.
Unicompartmental arthroplasty (UKA) is a successful procedure for the treatment of focal arthritis or osteonecrosis of the medial or lateral compartments of the knee. While UKA may pose lower risk of perioperative complications and achieve better functional outcomes than TKA, a high degree of accuracy of implant positioning and soft tissue balance are required to optimize durability and implant survivorship. First generation robotic technology improved substantially implant position compared to conventional methods; however, high capital costs, uncertainty regarding the value of advanced technologies, and the need for preoperative CT scans were barriers to broader adoption. This paper reviews the next generation robotic technology – an image-free hand-held robotic sculpting tool -- which offers an alternative method for optimizing implant positioning and soft tissue balance without the need for preoperative CT scans and with price points that make it suitable for use in an outpatient surgery center.
Purpose:
The sulcus line (SL) is a three-dimensional curve produced from multiple points along the trochlear groove. Whiteside's Line, also known as the anteroposterior axis (APA), is derived from single anterior and posterior points. The purposes of the two studies presented in this paper are to (1) assess the results from the clinical use of the SL in a large clinical series, (2) measure the SL and the APA on three-dimensional CT reconstructions, (3) demonstrate the effect of parallax error on the use of the APA and (4) determine the accuracy of an axis derived by combining the SL and the posterior condylar axis (PCA).
Methods:
In the first study, we assessed the SL using a large, single surgeon series of consecutive patients undergoing primary total knee arthroplasties. The post-operative CT scans of patients (n = 200) were examined to determine the final rotational alignment of the femoral component. In the second study, measurements were taken in a series of 3DCT reconstructions of osteoarthritic knees (n = 44).
Results:
The mean position of the femoral component in the clinical series was 0.6° externally rotated to the surgical epicondylar axis, with a standard deviation of 2.9° (ranges from -7.2° to 6.7°). On the 3DCT reconstructions, the APA (88.2° ± 4.2°) had significantly higher variance than the SL (90.3° ± 2.7°) (F = 5.82 and p = 0.017). An axis derived by averaging the SL and the PCA+3° produced a significant decrease in both the number of outliers (p = 0.03 vs. PCA and p = 0.007 vs. SL) and the variance (F = 6.15 and p = 0.015 vs. SL). The coronal alignment of the SL varied widely relative to the mechanical axis (0.4° ± 3.8°) and the distal condylar surface (2.6° ± 4.3°).
Conclusions:
The multiple points used to determine the SL confer anatomical and geometrical advantages, and therefore, it should be considered a separate rotational landmark to the APA. These findings may explain the high degree of variability in the measurement of the APA which is documented in the literature. Combining a geometrically correct SL and the PCA is likely to further improve accuracy.
Although computer-assisted navigation has been used in clinical practice for more than 15 years, it has only recently started to gain acceptance in a variety of orthopedic procedures. Different types of computer-assisted navigation are available, which allow the surgeon to obtain real-time feedback and offer him the potential to decrease intraoperative errors. However, its increased cost and lacking evidence of long-term superiority have made many surgeons skeptical about its clinical usefulness. The scope of this article is to review the clinical applications of computer-assisted navigation in orthopedic surgery of the knee joint.
Various systems of computer-assisted orthopaedic surgery (CAOS) in total hip arthroplasty (THA) were reviewed. The first clinically applied system was an active robotic system (ROBODOC), which performed femoral implant cavity preparation as programmed preoperatively. Several reports on cementless THA with ROBODOC showed better stem alignment and less variance in limb-length inequality on radiographic evaluation, less incidence of pulmonary embolic events on transesophageal cardioechogram, and less stress shielding on the dual energy X-ray absorptiometry analysis than conventional manual methods. On the other hand, some studies raise issues with active systems, including a steep learning curve, muscle and nerve damage, and technical complications, such as a procedure stop due to a bone motion during cutting, requiring re-registration and registration failure. Semi-active robotic systems, such as Acrobot and Rio, were developed for ease of surgeon acceptance. The drill bit at the tip of the robotic arm is moved by a surgeon's hand, but it does not move outside of a milling path boundary, which is defined according to three-dimensional (3D) image-based preoperative planning. However, there are still few reports on THA with these semi-active systems. Thanks to the advancements in 3D sensor technology, navigation systems were developed. Navigation is a passive system, which does not perform any actions on patients. It only provides information and guidance to the surgeon who still uses conventional tools to perform the surgery. There are three types of navigation: computed tomography (CT)-based navigation, imageless navigation, and fluoro-navigation. CT-based navigation is the most accurate, but the preoperative planning on CT images takes time that increases cost and radiation exposure. Imageless navigation does not use CT images, but its accuracy depends on the technique of landmark pointing, and it does not take into account the individual uniqueness of the anatomy. Fluoroscopic navigation is good for trauma and spine surgeries, but its benefits are limited in the hip and knee reconstruction surgeries. Several studies have shown that the cup alignment with navigation is more precise than that of the conventional mechanical instruments, and that it is useful for optimizing limb length, range of motion, and stability. Recently, patient specific templates, based on CT images, have attracted attention and some early reports on cup placement, and resurfacing showed improved accuracy of the procedures. These various CAOS systems have pros and cons. Nonetheless, CAOS is a useful tool to help surgeons perform accurately what surgeons want to do in order to better achieve their clinical objectives. Thus, it is important that the surgeon fully understands what he or she should be trying to achieve in THA for each patient.
Introduction
“Navigation in surgery” spans a broad area, which, depending on the clinical challenge, can have different meanings. Over the past decade, navigation in surgery has evolved beyond imaging modalities and bulky systems into the rich networking of the cloud or devices that are pocket-sized.
Discussion
This article will review various aspects of navigation in the operating room and beyond. This includes a short history of navigation, the evolution of surgical navigation, as well as technical aspects and clinical benefits with examples from neurosurgery, spinal surgery, and orthopedics.
Conclusion
With improved computer technology and a trend towards advanced information processing within hospitals, navigation is quickly becoming an integral part in the surgical routine of clinicians.
Orthopaedic residents typically learn to perform total knee arthroplasty (TKA) through an apprenticeship-type model, which is a necessarily slow process. Surgical skills courses, using artificial bones, have been shown to improve technical and cognitive skills significantly within a couple of days. The addition of computer-assisted surgery (CAS) simulations challenges the participants to consider the same task in a different context, promoting cognitive flexibility. We designed a hands-on educational intervention for junior residents with a conventional tibiofemoral TKA station, two different tibiofemoral CAS stations, and a CAS and conventional patellar resection station, including both qualitative and quantitative analyses. Qualitatively, structured interviews before and after the course were analyzed for recurring themes. Quantitatively, subjects were evaluated on their technical skills before and after the course, and on a multiple-choice knowledge test and error detection test after the course, in comparison to senior residents who performed only the testing. Four themes emerged: confidence, awareness, deepening knowledge and changed perspectives. The residents' attitudes to CAS changed from negative before the course to neutral or positive afterwards. The junior resident group completed 23% of tasks in the pre-course skills test and 75% of tasks on the post-test (p<0.01), compared to 45% of tasks completed by the senior resident group. High-impact educational interventions, promoting cognitive flexibility, would benefit trainees, attending surgeons, the healthcare system and patients.
The aim of this study is to evaluate the accuracy of VISIONAIRE (Smith & Nephew Inc., Memphis, TN, USA) Patient Matched cutting tibial jigs in comparison with extramedullary (EM) tibial instrumentation by analysing data as detected by intra-operative use of VectorVision knee navigation software from BrainLAB (Redwood City, CA, USA).
Twelve patients were selected for unilateral total knee replacement (TKR). They underwent a full-length weight-bearing anteroposterior (AP) radiograph and magnetic resonance imaging (MRI). During surgery, once the EM guides were placed and fixed on the tibia, the orientation in the coronal and sagittal planes was checked by the navigator and then compared with the data obtained by measuring the orientation of VISIONAIRE Patient Matched cutting tibial jigs. An unsatisfactory result was considered an error ≥2° in both coronal and sagittal planes for the tibial component as a possible error of 4° could result.
In the coronal plane the mean deviation of the EM tibial guides from the ideal alignment (0°) was 0.7 ± 0.39° and of the VISIONAIRE was 129 ± 1.55° (P = 0.22). In the sagittal plane the mean deviation of the EM tibial guides from 3° of posterior slope was -1.62 ± 1.78° and of the VISIONAIRE was +1.16 ± 4.29° (P < 0.05). Negative values indicate a more posterior slope from the ideal and positive values an anterior slope.
This preliminary study documented only a fair accuracy of the method with a consistent risk of error of more of 3° especially in the sagittal plane. We could speculate that the problem in the sagittal plane was due to the fact that the pre-operative protocol does not include a lateral X-ray projection of the knee and only includes an AP standing X-ray of the straight leg and MRI.
Computer assisted surgery (CAS) was used to improve the positioning of implants during total knee arthroplasty (TKA). Most studies have reported that computer assisted navigation reduced the outliers of alignment and component malpositioning. However, additional sophisticated studies are necessary to determine if the improvement of alignment will improve long-term clinical results and increase the survival rate of the implant. Knowledge of CAS-TKA technology and understanding the advantages and limitations of navigation are crucial to the successful application of the CAS technique in TKA. In this article, we review the components of navigation, classification of the system, surgical method, potential error, clinical results, advantages, and disadvantages.
Background:
We previously reported the short-term radiographic and functional results of a randomized controlled trial (RCT) comparing computer-assisted and conventionally performed total knee replacement. We currently report the 2-year clinical results from this trial.
Methods:
One hundred and ninety patients were randomly allocated to undergo either computer-assisted or conventional total knee replacement. One hundred and seventy-two patients were available for clinical evaluation at 2 years, and 167 (97%) of those answered all patient-reported outcome measures (PROMs), including the Knee Injury and Osteoarthritis Outcome Score (KOOS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee Society Score (KSS), visual analog scale (VAS), and EuroQol-5 Dimensions (EQ-5D). Patients and clinical evaluators were blinded to the method of surgery. Surgical outcome was assessed using the Outcome Measures in Rheumatology-Osteoarthritis Research Society International (OMERACT-OARSI) criteria to calculate responder rates, divided into high responders, moderate responders, and nonresponders.
Results:
The computer-assisted group had significantly more improvement than the conventional group in the mean scores for 2 subscales of the KOOS (7.4 for symptoms [p = 0.02] and 16.2 for sport and recreation [p < 0.01]) and in 1 subscale of the WOMAC (8.8 for stiffness [p = 0.03]).The computer-assisted group also had significantly more high responders (82.8%) than the conventional group (68.8%; p = 0.03) at 2 years, with the number needed to treat determined to be 8.
Conclusions:
In this study, the use of computer navigation provided better pain relief and restored better function than the use of the conventional surgical technique at 2 years after total knee replacement.
Level of evidence:
Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.
The history of osteoarthritis (OA) is important because it can help broaden our perspective on past and present controversies. The naming of OA, beginning with Heberden's nodes, is itself a fascinating story. According to Albert Hoffa, R. Llewellyn Jones and Archibald Edward Garrod, the name OA was introduced in the mid-19th century by surgeon Richard von Volkmann who distinguished it from rheumatoid arthritis and gout. Others preferred the terms 'chronical rheumatism', 'senile arthritis', 'hypertrophic arthritis' or 'arthritis deformans'. A similar narrative applies to the concept of OA affecting the whole joint vs. the 'wear-and-tear' hypothesis, inflammation and the role of the central nervous system (CNS). In the late 19th and early 20th centuries, the Garrods (father and son) and Hermann Senator argued that OA was a whole joint disease, and that inflammation played a major role in its progression. Garrod Jnr and John Spender also linked OA to a neurogenic lesion 'outside the joint'. The remaining 20th century was no less dynamic, with major advances in basic science, diagnostics, treatments, surgical interventions and technologies. Today, OA is characterized as a multi-disease with inflammation, immune and CNS dysfunction playing central roles in whole joint damage, injury progression, pain and disability. In the current 'omics' era (genomics, proteomics and metabolomics), we owe a great debt to past physicians and surgeons who dared to think 'outside-the-box' to explain and treat OA. Over 130 years later, despite these developments, we still don't fully understand the unravelling complexities of OA, and we still don't have a cure.
Background
Total knee replacements (TKR) aim to restore stability of the tibiofemoral and patella-femoral joints and provide relief of pain and improved quality of life for the patient. In recent years, computer-assisted navigation systems have been developed with the aim of reducing human error in joint alignment and improving patient outcomes. Methods
We examined the current body of evidence surrounding the use of navigation systems and discussed their current and future role in TKR. ResultsThe current body of evidence shows that the use of computer navigation systems for TKR significantly reduces outliers in the mechanical axis and coronal prosthetic position. Also, navigation systems offer an objective assessment of soft tissue balancing that had previously not been available. Although these benefits represent a technical superiority to conventional TKR techniques, there is limited evidence to show long-term clinical benefit with the use of navigation systems, with only a small number of studies showing improvement in outcome scores at short-term follow-up. Because of the increased costs and operative time associated with their use as well as the emergence of more affordable and patient-specific technologies, it is unlikely for navigation systems to become more widely used in the near future. Conclusions
Whilst this technology helps surgeons to achieve improved component positioning, it is important to consider the clinical and functional implications, as well as the added costs and potential learning curve associated with adopting new technology.
Background:
Computer-assisted surgical (CAS) navigation has been developed with the aim of improving the accuracy and precision of total knee arthroplasty (TKA) component positioning and therefore overall limb alignment. The historical goal of knee arthroplasty has been to restore the mechanical alignment of the lower limb by aligning the femoral and tibial components perpendicular to the mechanical axis of the femur and tibia. Despite over 4 decades of TKA component development and nearly 2 decades of interest in CAS, the fundamental question remains; does the alignment goal and/or the method of achieving that goal affect the outcome of the TKA in terms of patient-reported outcome measures and/or overall survivorship? The quest for reliable and reproducible achievement of the intraoperative alignment goal has been the primary motivator for the introduction, development, and refinement of CAS navigation. Numerous proprietary systems now exist, and rapid technological advancements in computer processing power are stimulating further development of robotic surgical systems. Three categories of CAS can be defined: image-based large-console navigation; imageless large-console navigation, and more recently, accelerometer-based handheld navigation systems have been developed.
Conclusion:
A review of the current literature demonstrates that there are enough well-designed studies to conclude that both large-console CAS and handheld navigation systems improve the accuracy and precision of component alignment in TKA. However, missing from the evidence base, other than the subgroup analysis provided by the Australian Orthopaedic Association National Joint Replacement Registry, are any conclusive demonstrations of a clinical superiority in terms of improved patient-reported outcome measures and/or decreased cumulative revision rates in the long term. Few authors would argue that accuracy of alignment is a goal to ignore; therefore, in the absence of clinical evidence, many of the arguments against the use of large-console CAS navigation center on the prohibitive cost of the systems. The utilization of low-cost, handheld CAS navigation systems may therefore bridge this important gap, and over time, further clinical evidence may emerge.
I explore here how trainees in a community of practice learn new techniques and technologies when approved practices for learning are insufficient. I do so through two studies: a two-year, five-sited, comparative ethnographic study of learning in robotic and traditional surgical practice, and a blinded interview-based study of surgical learning practices at 13 top-tier teaching hospitals around the U.S. I found that learning surgery through increasing participation using approved methods worked well in traditional (open) surgery, as current literature would predict. But the radically different practice of robotic surgery greatly limited trainees’ role in the work, making approved methods ineffective. Learning surgery in this context required what I call “shadow learning”: an interconnected set of norm- and policy-challenging practices enacted extensively, opportunistically, and in relative isolation that allowed only a minority of robotic surgical trainees to come to competence. Successful trainees engaged extensively in three practices: “premature specialization” in robotic surgical technique at the expense of generalist training; “abstract rehearsal” before and during their surgical rotations when concrete, empirically faithful rehearsal was prized; and “undersupervised struggle,” in which they performed robotic surgical work close to the edge of their capacity with little expert supervision—when norms and policy dictated such supervision. Shadow learning practices were neither punished nor forbidden, and they contributed to significant and troubling outcomes for the cadre of initiate surgeons and the profession, including hyperspecialization and a decreasing supply of experts relative to demand.
Nowadays, operating rooms can be inefficient and overcrowded. Patient data and images are at times not well integrated and displayed in a timely fashion. This lack of coordination may cause further reductions in efficiency, jeopardize patient safety, and increase costs. Fortunately, technology has much to offer the surgical disciplines and the ongoing and recent operating room innovations have advanced preoperative planning and surgical procedures by providing visual, navigational, and mechanical computerized assistance. The field of computer-assisted surgery (CAS) broadly refers to surgical interface between surgeons and machines. It is also part of the ongoing initiatives to move away from invasive to less invasive or even noninvasive procedures. CAS can be applied preoperatively, intraoperatively, and/or postoperatively to improve the outcome of orthopaedic surgical procedures as it has the potential for greater precision, control, and flexibility in carrying out surgical tasks, and enables much better visualization of the operating field than conventional methods have afforded. CAS is an active research discipline, which brings together orthopaedic practitioners with traditional technical disciplines such as engineering, computer science, and robotics. However, to achieve the best outcomes, teamwork, open communication, and willingness to adapt and adopt new skills and processes are critical. Because of the relatively short time period over which CAS has developed, long-term follow-up studies have not yet been possible. Consequently, this review aims to outline current CAS applications, limitations, and promising future developments that will continue to impact the operating room (OR) environment and the OR in the future, particularly within orthopedic and spine surgery.
Purpose:
Our aim was to compare the long-term outcome between navigated and conventional total knee arthroplasty (TKA), which is currently not known.
Methods:
Long-term survivorship, clinical scores and radiographic results of a matched-pair group of 350 patients (350 knees) treated with navigated (n = 157) or conventional (n = 188) TKA for osteoarthritis over a period of 11 years were reviewed retrospectively.
Results:
The mean clinical follow-up was ten years. There were no clinically relevant differences with respect to any clinical outcome, patient satisfaction or pain between the two groups. Coronal leg alignment was closer (1.7-3.1°) to the neutral mechanical axis in the navigated group compared with the conventional group (2.6-4.7°). A total of 12 knees (6.4%) in the conventional group and three (1.9%) in the navigated group underwent revision surgery (p = 0.04), resulting in an absolute risk reduction of 4.5% for revision surgery by using navigation. Using any revision as an end point, the ten-year Kaplan-Meier survivorship was 98.1% in the navigated and 92.5% in the conventional group.
Conclusions:
Navigated TKA improves implant survivorship compared with conventional TKA.
Computer-assisted surgery for total knee arthroplasty can be performed with use of computer-assisted navigation, handheld navigation, partially or fully robot-assisted technology, and patient-specific instrumentation.
➢ Computer-assisted navigation leads to improved component alignment and a reduction in the likelihood of mechanical axis outliers after total knee arthroplasty, but it is not known whether these differences have any long-term benefit on clinical or functional outcomes.
➢ Handheld navigation is a form of computer-assisted navigation that includes accelerometer and sensor-based technology. While largely unproven in the clinical literature, it offers many potential advantages over traditional navigation.
➢ Robot-assisted surgery has not been extensively studied in the context of unicompartmental and total knee arthroplasty, and, although initial reports have been promising in terms of accuracy and precision, this method is associated with substantial cost and a steep learning curve.
➢ Patient-specific instrumentation was designed to overcome many of the intraoperative challenges associated with navigation or robotic surgery, but early reports have demonstrated only minor improvements in surgical accuracy, and no change in outcomes, compared with conventional total knee arthroplasty.
Aims:
Accurate placement of the acetabular component during total hip arthroplasty (THA) is an important factor in the success of the procedure. However, the reported accuracy varies greatly and is dependent upon whether free hand or navigated techniques are used. The aim of this study was to assess the accuracy of an instrument system that incorporates 3D printed, patient-specific guides designed to optimise the placement of the acetabular component.
Patients and methods:
A total of 100 consecutive patients were prospectively enrolled and the accuracy of placement of the acetabular component was measured using post-operative CT scans.
Patients and methods:
A total of 100 consecutive patients were prospectively enrolled and the accuracy of placement of the acetabular component was measured using post-operative CT scans.
Conclusion:
Accurate placement of the acetabular component can be achieved using patient-specific guides and is superior to free hand techniques and comparable to navigated and robotic techniques. Cite this article: Bone Joint J 2016;98-B:1342-6.
Recently, there is a growing interest in surgical variables that are intraoperatively controlled by orthopaedic surgeons, including lower leg alignment, component positioning and soft tissues balancing. Since more tight control over these factors is associated with improved outcomes of unicompartmental knee arthroplasty and total knee arthroplasty (TKA), several computer navigation and robotic-assisted systems have been developed. Although mechanical axis accuracy and component positioning have been shown to improve with computer navigation, no superiority in functional outcomes has yet been shown. This could be explained by the fact that many differences exist between the number and type of surgical variables these systems control. Most systems control lower leg alignment and component positioning, while some in addition control soft tissue balancing. Finally, robotic-assisted systems have the additional advantage of improving surgical precision.
A systematic search in PubMed, Embase and Cochrane Library resulted in 40 comparative studies and three registries on computer navigation reporting outcomes of 474,197 patients, and 21 basic science and clinical studies on robotic-assisted knee arthroplasty. Twenty-eight of these comparative computer navigation studies reported Knee Society Total scores in 3504 patients. Stratifying by type of surgical variables, no significant differences were noted in outcomes between surgery with computer-navigated TKA controlling for alignment and component positioning versus conventional TKA (p = 0.63). However, significantly better outcomes were noted following computer-navigated TKA that also controlled for soft tissue balancing versus conventional TKA (mean difference 4.84, 95 % Confidence Interval 1.61, 8.07, p = 0.003). A literature review of robotic systems showed that these systems can, similarly to computer navigation, reliably improve lower leg alignment, component positioning and soft tissues balancing. Furthermore, two studies comparing robotic-assisted with computer-navigated surgery reported superiority of robotic-assisted surgery in controlling these factors.
Manually controlling all these surgical variables can be difficult for the orthopaedic surgeon. Findings in this study suggest that computer navigation or robotic assistance may help managing these multiple variables and could improve outcomes. Future studies assessing the role of soft tissue balancing in knee arthroplasty and long-term follow-up studies assessing the role of computer-navigated and robotic-assisted knee arthroplasty are needed.
Purpose
The purpose of this study was to assess the midterm results of total knee arthroplasty (TKA) implanted with a specific computer navigation system in a group of patients (NAV) and to assess the same prosthesis implanted with the conventional technique in another group (CON); we hypothesized that computer navigation surgery would improve implant alignment, functional scores and survival of the implant compared to the conventional technique.
Methods
From 2008 to 2009, 225 patients were enrolled in the study and randomly assigned in CON and NAV groups; 240 consecutive mobile-bearing ultra-congruent score (Amplitude, Valence, France) TKAs were performed by a single surgeon, 117 using the conventional method and 123 using the computer-navigated approach. Clinical outcome assessment was based on the Knee Society Score (KSS), the Hospital for Special Surgery Knee Score and the Western Ontario Mac Master University Index score. Component survival was calculated by Kaplan–Meier analysis.
Results
Median follow-up was 6.4 years (range 6–7 years). Two patients were lost to follow-up. No differences were seen between the two groups in age, sex, BMI and side of implantation. Three patients of CON group referred feelings of instability during walking, but clinical tests were all negative. NAV group showed statistical significant better KSS Score and wider ROM and fewer outliers from neutral mechanical axis, lateral distal femoral angle, medial proximal tibial angle and tibial slope in post-operative radiographic assessment. There was one case of early post-operative superficial infection (caused by Staph. Aureus) successfully treated with antibiotics. No mechanical loosening, mobile-bearing dislocation or patellofemoral complication was seen. At 7 years of follow-up, component survival in relation to the risk of aseptic loosening or other complications was 100 %. There were no implant revisions.
Conclusion
This study demonstrates superior accuracy in implant positioning and statistical significant better functional outcomes of computer-navigated TKA. Computer navigation for TKAs should be used routinely in primary implants.
Level of evidence
II.
PurposeKinematic alignment in TKA is supposed to restore function by aligning the components to the premorbid flexion–extension axis instead of altering the joint line and natural kinematic axes of the knee. The purpose of this study was to compare mechanically aligned TKA to kinematic alignment. Methods
In this study, 200 patients underwent TKA and were randomly assigned to 2 groups: 100 TKAs were performed using kinematic alignment with custom-made cutting guides in order to complete cruciate-retaining TKA; the other 100 patients underwent TKA that was manually performed using mechanical alignment. The WOMAC and combined Knee Society Score (KSS), as well as radiological alignment, were determined as outcome parameters at the 12-month endpoint. ResultsWOMAC and KSS significantly improved in both groups. There was a significant difference in both scores between groups in favour of kinematic alignment. Although the kinematic alignment group demonstrated significantly better overall results, more outliers with poor outcomes were also seen in this group. A correlation between post-operative alignment deviation from the initial plan and poor outcomes was also noted. The most important finding of this study is that applying kinematic alignment in TKA achieves comparable results to mechanical alignment in TKA. This study also shows that restoring the premorbid flexion–extension axis of the knee joint leads to better overall functional results. Conclusion
Kinematic alignment is a favourable technique for TKA. Clinical relevanceThe kinematic alignment idea might be a considerable alternative to mechanical alignment in the future. Level of evidenceII.
Surgical robotics and supporting technologies have really become a prime example of modern applied information technology infiltrating our everyday lives. The development of these systems spans across four decades, and only the last few years brought the market value and saw the rising customer base imagined already by the early developers. This chapter guides the reader through the historical development of the most important systems and provides references and lessons learnt for current engineers facing similar challenges. A special emphasis is put on system validation, assessment, and clearance, as the most commonly cited barrier hindering the wider deployment of a system.
Background:
Unicompartmental knee arthroplasty (UKA) is a treatment option for single-compartment knee osteoarthritis. Robotic assistance may improve survival rates of UKA, but the cost-effectiveness of robot-assisted UKA is unknown. The purpose of this study was to delineate the revision rate, hospital volume, and robotic system costs for which this technology would be cost-effective.
Methods:
We created a Markov decision analysis to evaluate the costs, outcomes, and incremental cost-effectiveness of robot-assisted UKA in 64-year-old patients with end-stage unicompartmental knee osteoarthritis.
Results:
Robot-assisted UKA was more costly than traditional UKA, but offered a slightly better outcome with 0.06 additional quality-adjusted life-years at an incremental cost of 1.426 million.
Conclusion:
Robot-assisted UKA is cost-effective compared with traditional UKA when annual case volume exceeds 94 cases per year. It is not cost-effective at low-volume or medium-volume arthroplasty centers.
Background:
Computer navigation for total knee arthroplasty has improved alignment compared with that resulting from non-navigated total knee arthroplasty. This study analyzed data from the Australian Orthopaedic Association National Joint Replacement Registry to examine the effect of computer navigation on the rate of revision of primary total knee arthroplasty.
Methods:
The cumulative percent revision following all non-navigated and navigated primary total knee arthroplasties performed in Australia from January 1, 2003, to December 31, 2012, was assessed. In addition, the type of and reason for revision as well as the effect of age, surgeon volume, and use of cement for the prosthesis were examined. Kaplan-Meier estimates of survivorship were used to describe the time to first revision. Hazard ratios (HRs) from Cox proportional hazards models, with adjustment for age and sex, were used to compare revision rates.
Results:
Computer navigation was used in 44,573 (14.1% of all) primary total knee arthroplasties, and the rate of its use increased from 2.4% in 2003 to 22.8% in 2012. Overall, the cumulative percent revision following non-navigated total knee arthroplasty at nine years was 5.2% (95% confidence interval [CI] = 5.1 to 5.4) compared with 4.6% (95% CI = 4.2 to 5.1) for computer-navigated total knee arthroplasty (HR = 1.05 [95% CI = 0.98 to 1.12], p = 0.15). There was a significant difference in the rate of revision following non-navigated total knee arthroplasty compared with that following navigated total knee arthroplasty for younger patients (HR = 1.13 [95% CI = 1.03 to 1.25], p = 0.011). Patients less than sixty-five years of age who had undergone non-navigated total knee arthroplasty had a cumulative percent revision of 7.8% (95% CI = 7.5 to 8.2) at nine years compared with 6.3% (95% CI = 5.5 to 7.3) for those who had undergone navigated total knee arthroplasty. Computer navigation led to a significant reduction in the rate of revision due to loosening/lysis (HR = 1.38 [95% CI = 1.13 to 1.67], p = 0.001), which is the most common reason for revision of total knee arthroplasty.
Conclusions:
Computer navigation reduced the overall rate of revision and the rate revision for loosening/lysis following total knee arthroplasty in patients less than sixty-five years of age.
A prospective comparative study was conducted to compare the mechanical axis post total knee arthroplasty (TKA) between two groups: In the first group of 100 knees (ASM group) Articular Surface Mounted navigation system was used to guide the distal femoral cut. In the second group of 100 knees (JIG group) conventional intramedullary femoral jig was used. The postoperative mechanical axis of the leg was within 3° of neutral alignment in 90% of the TKA in the ASM group (mean 178.12°) as compared to 74% in the JIG group (mean 177.02°). This difference was statistically significant (P<0.05). The data presented show that the use of limited femoral navigation leads to more accurate restoration of mechanical axis alignment when compared to conventional intramedullary femoral jigs.
Copyright © 2014 Elsevier Inc. All rights reserved.
Purpose
Restoring a neutral mechanical axis in total knee arthroplasty (TKA) (within ±3° of varus/valgus) is associated with superior functional outcome and reduced early implant failure. Using conventional alignment jigs results in malalignment in >20 % of cases. In this study, we investigated the reduction of outliers within the threshold of ±3° of leg alignment using a “pinless” navigation system in comparison with conventional alignment jigs investigated.
Methods
In this randomised prospective study, 80 patients were randomly assigned/allocated to the pinless or conventional control group. After surgery, the two groups were compared regarding outliers > ±3° by means of hip–knee–ankle angle (HKA), mechanical medial proximal tibia angle (mMPTA), mechanical lateral distal femoral angle (mLDFA) and duration of surgery. Student’s unpaired t test was used for quantitative variables, Fisher’s exact test compared groups (pinless vs. control) and a two-sided p value of ≤0.05 was considered statistically significant.
Results
In the pinless group, outliers regarding HKA and mLDFA > ±3° was significantly reduced (p = 0.025 and p = 0.002 respectively). In the pinless group, the surgery duration was significantly longer (75.6 vs. 64.5 minutes, p ±3° regarding HKA without risking pin-related complications, such as fractures, infections or breaking screws. However, not all tools for conventional navigation in TKA, such as real-time measurements of the tibiofemoral axis and gap balancing, are available.
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. A significant increase of 16.9 minutes in mean operative time for computer-navigated TKA was observed ( P =.046). Although patients undergoing computer-navigated TKA had fewer outliers in mechanical axis (13.4%) compared with the conventional technique (27.4%), the results did not achieve statistical significance (I ² =0.0%; P =1.000). Fewer complications were observed in patients undergoing computer-navigated TKA (4%) compared with conventional TKA (6.5%).
The use of computer-navigated TKA reduced the number of outliers in mechanical axis compared with conventional TKA; however, it did not achieve statistical significance. Additional research with longer follow-up is recommended.
The aim of this study was to investigate the post-operative radiological outcomes of patient-specific instrumentation (PSI) surgery versus conventional total knee arthroplasty (TKA).
Sixty patients scheduled for a primary TKA were prospectively divided into PSI or conventional technique. Coronal and sagittal radiographic long limb films were taken post-operatively. The accepted values for normal alignment were 180° ± 3° for hip-knee-ankle angle; 90° ± 3° for coronal femoral component angle or coronal tibia component angle; 0° to 3° flexion for sagittal femoral component angle and 0° to 7° posterior slope for sagittal tibia component angle.
For hip-knee-ankle angle, there were 21 % more outliers in the PSI group compared to the conventional group (p = 0.045). Most of these outliers had valgus deformity in the PSI group and varus deformity in the conventional group (p = 0.045). For implant placement, there was no difference in the proportion of outliers between the two groups. There was also no difference in the duration of surgery.
This study showed that PSI surgery is associated with a larger proportion of outliers for lower limb alignment. PSI surgery as an alternative to conventional TKA is not advisable. LEVEL OF EVIDENCE: II.
The influence of joint distraction force on intraoperative soft tissue balance was evaluated using Offset Repo-Tensor® for 78 knees that underwent primary posterior-stabilized total knee arthroplasty. The joint center gap and varus ligament balance were measured between osteotomized surfaces using 20, 40 and 60lbs of joint distraction force. These values were significantly increased at extension and flexion as the distraction force increased. Furthermore, lateral compartment stiffness was significantly lower than medial compartment stiffness. Thus, larger joint distraction forces led to larger varus ligament balance and joint center gap, because of the difference in soft tissue stiffness between lateral and medial compartments. These findings indicate the importance of the strength of joint distraction force in the assessment of soft tissue balance, especially when using gap-balancing technique.
Recently, patient-specific guides (PSGs) have been introduced, claiming a significant improvement in accuracy and reproducibility of component positioning in TKA. Despite intensive marketing by the manufacturers, this claim has not yet been confirmed in a controlled prospective trial.
We (1) compared three-planar component alignment and overall coronal mechanical alignment between PSG and conventional instrumentation and (2) logged the need for applying changes in the suggested position of the PSG.
In this randomized controlled trial, we enrolled 128 patients. In the PSG cohort, surgical navigation was used as an intraoperative control. When the suggested cut deviated more than 3A degrees from target, the use of PSG was abandoned and marked as an outlier. When cranial-caudal position or size was adapted, the PSG was marked as modified. All patients underwent long-leg standing radiography and CT scan. Deviation of more than 3A degrees from the target in any plane was defined as an outlier.
The PSG and conventional cohorts showed similar numbers of outliers in overall coronal alignment (25% versus 28%; p = 0.69), femoral coronal alignment (7% versus 14%) (p = 0.24), and femoral axial alignment (23% versus 17%; p = 0.50). There were more outliers in tibial coronal (15% versus 3%; p = 0.03) and sagittal 21% versus 3%; p = 0.002) alignment in the PSG group than in the conventional group. PSGs were abandoned in 14 patients (22%) and modified in 18 (28%).
PSGs do not improve accuracy in TKA and, in our experience, were somewhat impractical in that the procedure needed to be either modified or abandoned with some frequency.
Level I, therapeutic study. See instructions for authors for a complete description of levels of evidence.
The purpose of this review was to appraise the use of computer-assisted navigation in total knee arthroplasty and to assess whether this technology has improved clinical outcomes. Studies were identified through searches in MEDLINE, Embase, and PubMed. Numerous studies have shown improved leg and component alignment using navigation systems. However, the better alignment achieved in navigated knee arthroplasty has not been shown to lead to better clinical outcomes. Navigated knee arthroplasty had lower calculated blood loss and lower incidence of fat embolism compared with conventional knee arthroplasty using intramedullary jigs. It may be most valued when dealing with complex knee deformities, revision surgery, or minimally invasive surgery. Navigated knee arthroplasty, however, is only cost-effective in centers with a high volume of joint replacements. Overall, computer-assisted navigated knee arthroplasty provides some advantages over conventional surgery, but its clinical benefits to date are unclear and remain to be defined on a larger scale.
We performed this study to determine whether the use of imageless navigation reduces revision rates after total knee arthroplasty (TKA).
Data of 1,121 consecutive primary TKA with a follow-up of one to six years were retrospectively analysed. Following the conversion of the standard technique from conventional to navigated procedures, these data included the last 342 conventional and first 779 navigated procedures performed in our clinic. Demographic and perioperative covariates were recorded. All patients were asked by post to report instances of revisions.
Data of 1,054 patients (94 %) were complete. Mean follow-up was 3.9 years for conventional and 2.4 years for navigated operations. Cumulative revision rate averaged 4.7 % for conventional and 2.3 % for navigated procedures. Cox's proportional hazard model was used to assess the effect of covariates on survival, resulting in significantly lower revision rates for older patients (p < 0.001) and for the navigated technique (p = 0.012). The reduced revision rate for navigated operations was mainly caused by a significantly reduced rate of aseptic implant loosening (1.9 % vs. 0.1 %, p = 0.024).
Our study showed lower revision rates when computer navigation was used. However, due to the retrospective uncontrolled design, further prospective trials will be necessary to further evaluate this effect.
This paper presents an overview of the surgical robotics field, highlighting significant milestones and grouping the various propositions into cohorts. The review does not aim to be exhaustive but rather to highlight how surgical robotics is acting as an enabling technology for minimally invasive surgery. As such, there is a focus on robotic surgical solutions which are commercially available; research efforts which have not gained regulatory approval or entered clinical use are mostly omitted. The practice of robotic surgery is currently largely dominated by the da Vinci system of Intuitive Surgical (Sunnyvale, CA, USA) but other commercial players have now entered the market with surgical robotic products or are appearing in the horizon with medium and long term propositions. Surgical robotics is currently a vibrant research topic and new research directions may lead to the development of very different robotic surgical devices in the future—small, special purpose, lower cost, possibly disposable robots rather than the current large, versatile and capital expensive systems. As the trend towards minimally invasive surgery (MIS) increases, surgery becomes more technically demanding for surgeons and more challenging for medical device technologists and it is clear that surgical robotics has now an established foothold in medicine as an enabling technology of MIS.
Although there have been many studies focusing on the increasingly important assessment of patients' satisfaction, few studies have specifically addressed this issue for total hip arthroplasty (THA). The goals of this study were to measure patients' satisfaction with THA and to evaluate the relationships of expectations and outcome to patients' satisfaction. A total of 180 patients were surveyed 2 to 3 years after THA about their experiences with THA. Patients cited 45 different expectations, which were grouped into five categories reflecting improvement in pain, walking, psychological state, essential activities, and nonessential activities. Overall, 89% of patients were satisfied with the results of surgery. Lower rates of satisfaction were found in patients who had a better preoperative condition (as measured by the surgeons with The Hospital for Special Surgery Hip Scale), in patients who expected improvement in nonessential activities, and in patients who reported worse postoperative condition (as measured by self-assessment with the Hip Rating Questionnaire and the Medical Outcomes Study Short-form General Health Survey). Patients were also asked how they came to THA. Nearly 50% of patients were first referred to an orthopaedist by family or friends or based on their own knowledge. Seventy-four percent either had subsequently referred others for THA or would have done so if they knew someone with hip pain. This study demonstrates that satisfaction with THA is a complex phenomenon, affected by expectations, outcome, and what patients know about the procedure from their community network. A better understanding of THA satisfaction will enable better future selection of patients and an additional dimension of outcome, both of which are important to patients and payers.
A 42-item survey was developed and administered to determine patient perception of and satisfaction with total hip arthroplasty (THA) vs total knee arthroplasty (TKA). A total of 153 patients who had both primary THA and TKA for osteoarthritis with 1-year follow-up were identified. Survey response rate was 72%. Patients were more satisfied with THA meeting expectations for improvement in function and quality of life (P < .05), whereas pain relief expectations were equivalent. Most patients (70.9%) reported that TKA required more physiotherapy. One-year Oxford score and improvement in Oxford score from preoperative to 1 year were superior for THAs (P = .000). Despite equivalent pain relief, THAs trend toward higher satisfaction compared with TKAs. THA is more likely to "feel normal" with greater improvement in Oxford score. Recovery from TKA requires more physiotherapy and a longer time to achieve a satisfactory recovery status. Patients should be counseled accordingly.
Because of the significant risks associated with component malalignment, considerable resources are being utilized to develop technology to improve alignment and decrease outliers in knee replacement surgery. While computer-assisted surgery is more accurate and allows for decreased outliers when compared to traditional instrumentation, it is not a technology that can be utilized by all surgeons who perform total knee arthroplasty (TKA) due to increased operative times and cost. Recently, the creation and use of patient-customized cutting guides has been applied to TKA. Published studies and results from practice have shown customized patient instrumentation technology to have comparable or better implant alignment than traditional instrumentation and increased efficiency with regard to surgical preparation time, the amount of surgical instrumentation needed, and cost savings. For lower-volume/inexperienced surgeons, these advantages can be significant.