More accurate component alignment in navigated total knee arthroplasty has no clinical benefit at 5-year follow-up

Clinical Course of Pain and Function Following Total Knee Arthroplasty: A Systematic Review and Meta-Regression

BACKGROUND

Total knee arthroplasty (TKA) is widely considered a successful intervention for osteoarthritis and other degenerative knee diseases. This study addresses the need for a high-quality meta-analysis that outlines the clinical course of pain and function post-TKA.

METHODS

The review included prospective cohort studies assessing pain or function of patients undergoing primary TKA at baseline (preoperatively) and at least 2 additional time points including one at least 12 months postoperatively. Two reviewers independently screened references, extracted data, and assessed risk of bias using the Quality in Prognosis Studies tool. The time course of recovery of pain and function was modeled using fractional polynomial meta-regression.

RESULTS

In total, 191 studies with 59,667 patients were included, most with low risk of bias. The variance-weighted mean pain score (/100, 0 = no pain) was 64.0 (95% confidence interval [CI] 60.2-67.7) preoperatively, 24.1 (95% CI 20.3-27.9) at 3 months, 20.4 (95% CI 16.7-24.0) at 6 months, and 16.9 (95%CI 13.6-20.3) at 12 months, and remained low (10.1; 95% CI 4.8-15.4) at 10 years postoperatively. The variance-weighted mean function score (/100, 0 = worst function) was 47.1 (95% CI 45.7-48.4) preoperatively, 72.8 (95% CI 71.3-74.4) at 3 months, 76.3 (95% CI 74.7-77.8) at 6 months, and 78.1 (95%CI 76.4-79.7) at 12 months. Function scores were good (79.7; 95% CI 77.9-81.5) at 10 years postoperatively.

CONCLUSION

Patients undergoing primary TKA can expect a large and rapid but incomplete recovery of pain and function in the first postoperative year. At 10 years, the gains in pain scores may still remain while there is an improvement in function.

Computer and robotic - assisted total knee arthroplasty: a review of outcomes

Background

Total knee arthroplasty (TKA) is a successful treatment for tricompartmental knee arthritis. Computer navigation and robotic-assisted-surgery (RAS) have emerged as tools that aim to help plan and execute surgery with greater precision and consistency. We reviewed the most current literature to describe the historical background and outcomes compared to conventional TKA.

Methods

A review and synthesis of the literature comparing the patient reported outcomes (PROM’s) of RA TKA and computer-assisted (CA) TKA to conventional TKA was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

Results

CAS TKA improves accuracy and consistency of implant position, and appears to provide a small improvement in PROMs and implant survival compared to conventional TKA. RTKA similarly improves implant accuracy compared to conventional techniques and early results suggest a similar small benefit in PROMs compared to conventional TKA. A strengthening trend is emerging showing CAS TKA has greatest benefit to implant survival in people under 65. RTKA survival analysis data is more limited and early results do not allow strong conclusions, however early trends are similar to CAS TKA.

Conclusion

Results for CAS-TKA show improvement in alignment, and early clinical outcomes have revealed promising results, with longer-term data and medium-term survival analysis recently emerging showing small benefits over conventional TKA. RTKA represents another phase of development. Early results show similar trends to that of CAS TKA with longer-term data still to come.

Computer Navigation-Assisted Knee Replacement Demonstrates Improved Outcome Compared with Conventional Knee Replacement at Mid-Term Follow-up: A Systematic Review and Meta-analysis

The study is a systematic review and meta-analysis of prospective randomised control studies and prospective cohort studies of mid-term functional outcome of total knee replacement undertaken using imageless computer navigation compared with conventional instrumented total knee replacement. The literature search strategy included a search of the electronic databases, visual scanning of reference lists, hand searching of key journals and conference proceedings, and abstracts, citations, and trial registers. In total, 440 papers were retrieved after removal of duplicates, and with further screening, 11 papers were included in the systematic review and 6 papers were considered appropriate for meta-analysis. Analysis of the data showed evidence of a modest improvement in functional outcome at mid-term follow-up with use of imageless computer navigation assistance compared with conventional instrumented total knee replacement with a total score point estimate of 3.36 confidence interval (CI) (- 0.583, 7.298), objective score point estimate of 1.45 CI (0.11, 2.799), and functional score point estimate of 2.4, CI (- 1.174, 5.977). The predominant risk of bias was from random allocation and attrition. There is evidence of a modest improvement in functional outcome with the use of imageless computer navigation assistance compared with conventional instrumented total knee replacement at mid-term follow-up.

How are clinical outcomes related to the deviation severity of the tibiofemoral mechanical axis on coronal plane following knee arthroplasty?

OBJECTIVE

To analyze the effect of tibiofemoral mechanical axis (TFMA) deviation severity on clinical outcomes after total knee arthroplasty (TKA).

METHODS

We retrospectively reviewed the patients who underwent primary TKA between January 2002 and December 2010. After applying inclusion/exclusion criteria, we evaluated 70 knees of 51 patients. The mean ± SD follow-up period was 7.08 ± 1.34 years. The knees were divided into 3 groups based on TFMAs. The first group, identified as "well aligned," included the TFMAs that were neutral within 3° (0° ± 3°) of alignment. The second group, identified as "outliers 1," included the slightly deviated TFMAs (-3° to -6° valgus and +3° to +6° varus). The third group, identified as "outliers 2," included the severely deviated TFMAs of more than 6° from neutral alignment (<-6° valgus and > + 6° varus). The clinical outcomes of each group were compared by evaluating the Oxford Knee Score (OKS), visual analog scale (VAS), and Short Form-36 physical component summary (SF-36 PCS) and mental component summary (SF-36 MCS) scores.

RESULTS

We found that OKS, SF-36 PCS, and SF-36 MCS were nearly the same in the well-aligned and outliers 1 groups but worse in the outliers 2 group. VAS scores were nearly the same in all groups. (p > 0.05).

CONCLUSION

Function scores were impaired when the TFMA deviated more than 6° from neutral. However, the differences in clinical outcomes between well-aligned knees and those of outliers were not found to be statistically significant in the medium term.

Twelve-Year Follow-Up of Navigated Computer-Assisted Versus Conventional Total Knee Arthroplasty: A Prospective Randomized Comparative Trial

BACKGROUND

Navigated computer-assisted total knee arthroplasty (TKA) was introduced to expedite long-term survival based on improved postoperative implantation accuracy. However, long-term outcome data after 10 years or more are rare, even available meta-analyses show controversial study results.

METHODS

In a prospective randomized trial, 100 conventional TKAs (group CONV) were compared with 100 computer-assisted TKAs (group NAV) after a mean follow-up of 12 years postoperatively. A long-leg weight-bearing X-ray was performed for measuring mechanical axis of the limb, lateral distal femoral angle, and medial proximal tibial angle. Tibial slope, patella alpha angle, and radiolucent lines were also observed. Clinical investigation included evaluation of 4 different scores: Insall Knee Score, Western Ontario and MacMaster University Index score, Hospital for Special Surgery Knee Score, and visual analog scale.

RESULTS

Based on a follow-up rate of at least 75%, no difference in TKA survival was found 12 years postoperatively: 91.5% in group CONV vs 98.2% in group NAV (P = .181). Since 5-year follow-up, no additional TKA revision had been performed in both groups. Group CONV showed a nonsignificant higher inaccuracy of neutral lower limb axis (1.8° ± 1.4°) compared to group NAV (1.6° ± 1.7°, P = .700). All X-ray assessments were not significant different within both study groups (P ≥ .068). Clinical examination showed no differences in evaluations (P ≥ .204). All collected outcome score results were similar (P ≥ .222).

CONCLUSION

Twelve years postoperatively, no differences were found in terms of long-term survival, implantation accuracy, clinical outcome or score results.

Computer navigation and distal femoral reconstruction in the oncologic patient

OBJECTIVES

As adjuvant treatments for musculoskeletal malignancies improve expectations of preserved function increase. We questioned whether computer navigation for distal femoral reconstruction would improve outcomes.

METHODS

Twenty oncology patients were reviewed after distal femoral reconstruction using navigation. Outcomes included local recurrence, implant revision, patient function, patellofemoral complications and leg-length inequality.

RESULTS

Implant survivorship was 85% at 26 months. There were no local recurrences and 3 failures for aseptic loosening. Good functional outcomes were observed in remaining cases.

CONCLUSION

Computer navigation for distal femoral reconstruction resulted in acceptable functional outcomes and implant survivorship. Reduced local recurrence were observed at intermediate follow-up. Level of Evidence: Level IV.

Comparison of Midterm Outcomes of Minimally Invasive Computer-Assisted vs Minimally Invasive Jig-Based Total Knee Arthroplasty

BACKGROUND

Minimally invasive surgery (MIS) has perceived advantages in the early postoperative stage for total knee arthroplasty (TKA). It is not clear whether the improved radiographic alignment achieved by computer-assisted navigation surgery (CAS) improves midterm clinical outcomes. The aim of this study was to compare patient outcomes of MIS TKA performed with and without CAS after a minimum follow-up of 7 years.

METHODS

Between 2007 and 2009, 50 patients underwent CAS and MIS TKA, and 50 patients underwent jig-based MIS TKA in this prospective study. Ninety-six patients were evaluated after a mean follow-up of 7.7 years, and clinical and radiological evaluations were performed.

RESULTS

Midterm results demonstrated that the Knee Society knee score, function score, and range of motion were comparable in the 2 groups. The percentage of patients with the mechanical axis within ±3° of neutral was significantly higher in the CAS group than in the jig-based group (94% vs 79%, respectively; P = .038). No knees had loosening after TKA. However, 1 patient in the CAS group demonstrated late infection 4 years postoperatively.

CONCLUSION

CAS did not improve midterm outcomes after MIS TKA compared with jig-based surgery, although CAS reduced outliers in coronal alignment.

Current state of computer navigation and robotics in unicompartmental and total knee arthroplasty: a systematic review with meta-analysis

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.

Does post-operative knee awareness differ between knees in bilateral simultaneous total knee arthroplasty? Predictors of high or low knee awareness

PURPOSE

To evaluate the difference in post-operative knee awareness between knees in patients undergoing bilateral simultaneous total knee arthroplasty (TKA) and to assess factors predicting high or low knee awareness.

METHODS

This study was conducted on 99 bilateral simultaneous TKAs performed at our institution from 2008 to 2012. All patients received one set of questionnaires [Forgotten Joint Score (FJS) and Oxford Knee Score (OKS)] for each knee. Based on the FJS, the patients' knees were divided into two groups: "best" and "worst" knees. The median of the absolute difference in FJS and OKS within each patient was calculated. Multivariate linear regression was performed to identify factors affecting FJS.

RESULTS

The difference between knees was 1 point (CI 0-5) for the FJS and 1 point (CI 0-2) for the OKS. The FJS for females increased (decreasing awareness) with increasing age. Males had the highest FJS (lowest awareness) at the age of 67. An increase in the FJS (lower knee awareness) of 12.0 points was found for Kellgren-Lawrence (K-L) grades 3 + 4 compared with K-L grades 1 + 2. A preoperative anatomical alignment of 3° valgus resulted in the lowest FJS (highest knee awareness) with decreasing knee awareness for decreasing tibio-femoral angles. Post-operative alignment did not significantly affect FJS.

CONCLUSION

Knee awareness did not differ significantly between the "best" and the "worst" knee. Bilateral simultaneous TKA can be performed without compromising the result in one of the knees. Knee awareness after primary TKA was influenced by age, gender, preoperative knee alignment, and severity of OA.

LEVEL OF EVIDENCE

III.

Reliable Alignment in Total Knee Arthroplasty by the Use of an iPod-Based Navigation System

Axial alignment is one of the main objectives in total knee arthroplasty (TKA). Computer-assisted surgery (CAS) is more accurate regarding limb alignment reconstruction compared to the conventional technique. The aim of this study was to analyse the precision of the innovative navigation system DASH® by Brainlab and to evaluate the reliability of intraoperatively acquired data. A retrospective analysis of 40 patients was performed, who underwent CAS TKA using the iPod-based navigation system DASH. Pre- and postoperative axial alignment were measured on standardized radiographs by two independent observers. These data were compared with the navigation data. Furthermore, interobserver reliability was measured. The duration of surgery was monitored. The mean difference between the preoperative mechanical axis by X-ray and the first intraoperatively measured limb axis by the navigation system was 2.4°. The postoperative X-rays showed a mean difference of 1.3° compared to the final navigation measurement. According to radiographic measurements, 88% of arthroplasties had a postoperative limb axis within ±3°. The mean additional time needed for navigation was 5 minutes. We could prove very good precision for the DASH system, which is comparable to established navigation devices with only negligible expenditure of time compared to conventional TKA.

Navigation-assisted versus conventional total knee replacement: no difference in patient-reported outcome measures (PROMs) at 1 and 2 years

INTRODUCTION

Navigation technique for total knee replacement has been shown to improve accuracy of prosthesis alignment in several studies. The purpose was to compare the patient-reported outcome measures in primary total knee replacement (TKR) using navigation versus conventional surgical technique at 1- and 2-year follow-up.

MATERIALS AND METHODS

A retrospective review of prospectively collected patient-reported outcome data for 351 consecutively performed primary TKR was included in the study. The study group (N = 113) included patients who had Triathlon TKR using articular surface mounted (ASM Stryker) navigation technique and control group (N = 238) included patients who had Triathlon TKR using conventional jig. In addition to the WOMAC (Western Ontario and McMaster University Osteoarthritis Index) and SF-36 (Medical Outcomes Trust Short Form-36), a short self-report questionnaire evaluating the level of satisfaction, quality of life and whether patients would undergo knee replacement again.

RESULTS

WOMAC: no significant difference between the groups was noted in mean WOMAC pain, function and stiffness scores at 1- and 2-year follow-up. SF-36: no significant difference between the groups was seen except in the physical function component of score at 1 year (p = 0.019). Navigation group mean 56.78 (CI 51.06-62.5) versus conventional group mean 48.34 (44.68-52.01) but this difference was not observed at 2-year follow-up.

CONCLUSIONS

The overall patient-reported outcome scores improved after total knee replacement but appear to be comparable in both groups at 1- and 2-year follow-up.

Computer navigation for total knee arthroplasty reduces revision rate for patients less than sixty-five years of age

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.

Imageless computer navigation in total knee arthroplasty provides superior short term functional outcomes: a meta-analysis

Computer navigation in total knee arthroplasty (TKA) is intended to produce more reliable results, but its impact on functional outcomes has not been firmly demonstrated. Literature searches were performed for Level I randomized trials that compared TKA using imageless computer navigation to those performed with conventional instruments. Radiographic and functional outcomes were extracted and statistically analyzed. TKA performed with computer navigation was more likely to be within 3° of ideal mechanical alignment (87.1% vs. 73.7%, P < .01). Navigated TKAs had a higher increase in Knee Society Score at 3-month follow-up (68.5 vs. 58.1, P = .03) and at 12-32 month follow-up (53.1 vs. 45.8, P < .01). Computer navigation in TKA provides more accurate alignment and superior functional outcomes at short-term follow-up.

Midterm outcomes of electromagnetic computer-assisted navigation in minimally invasive total knee arthroplasty

Background

A combination of two emerging technologies, computer-assisted navigation and minimally invasive surgery, in total knee arthroplasty has gained increasing interests from orthopedic surgeons around the world. To date, there has never been any midterm study for clinical and radiographic outcomes from using an electromagnetic computer-assisted navigation system. In this study, we aimed to systematically compare clinical and radiographic outcomes of minimally invasive surgery in total knee arthroplasty (MIS-TKA) performed with and without electromagnetic computer-assisted navigation at immediate and midterm follow-ups.

Methods

A total of 151 patients (160 knees) who underwent MIS-TKA were randomized to be operated with electromagnetic computer-assisted navigation (group I: 75 patients, 80 knees) or without the navigation (group II: 76 patients, 80 knees). The clinical and radiographic outcomes of immediate, 6-week postoperative follow-up and average 6.1-year follow-up were compared.

Results

On immediate, 6-week postoperative follow-up, clinical and radiographic outcomes did not reveal any difference between the two groups except for the fact that the operative time was longer in the navigation group. On 6.1-year follow-up, a total of 58 patients (63 knees) from group I and 58 patients (61 knees) from group II were reevaluated. There were no significant differences in clinical and radiographic loosening and in complications between the two groups.

Conclusion

In this study, no significant differences of clinical and radiographic outcomes were found for immediate and midterm follow-ups of MIS-TKA performed with and without electromagnetic computer-assisted navigation except for the additional operating time in the navigation group.

No difference between computer-assisted and conventional total knee arthroplasty: five-year results of a prospective randomised study

PURPOSE

The use of computer-assisted surgery (CAS) in total knee arthroplasty (TKA) results in better limb and implant alignment compared to conventional TKA; however, it is unclear whether this translates to better mid- to long-term clinical outcome. This prospective randomised study comparing CAS and conventional TKA reports the functional and patient perceived outcomes at a follow-up of 5 years. The hypothesis was that there would be a difference in functional outcome or quality of life after mid-term follow-up.

METHODS

Sixty-seven patients were available for physical and radiological examination at 5 years. The Knee Society Score (KSS) was used to describe functional outcome and the Euroquol questionnaire for quality of life.

RESULTS

The mean total KSS for the CAS group improved from 91.1 (SD 22.3) points preoperatively to 157.4 (SD 21.9) and 150.2 (SD 30.4) points at 2 and 5 years, respectively. In the conventional group, the mean total KSS was 99.6 (SD 18.6) points preoperatively and 151.1 (SD 26.0) and 149.0 (SD 28.0) points at 2 and 5 years, respectively. The mean quality of life score improved from 48.2 (SD 16.5) points preoperatively to 67.4 (SD 16.3) and 66.8 (SD 22.2) points at 2 and 5 years in the CAS group, and from 52.2 (SD 17.1) points preoperatively to 65.6 (SD 14.6) and 61.7 (SD 19.3) points at 2 and 5 years, respectively, in the conventional TKA group. These differences were not statistically significant. There were radiolucent lines up to 2 mm in 11 knees (four CAS, seven conventional), but there were no changes in implant position.

CONCLUSIONS

There were no significant differences in functional or patient perceived outcome after mid-term follow-up in this study.

LEVEL OF EVIDENCE

I.

Osteolysis around total knee arthroplasty: a review of pathogenetic mechanisms

Aseptic loosening and other wear-related complications are some of the most frequent late reasons for revision of total knee arthroplasty (TKA). Periprosthetic osteolysis (PPOL) pre-dates aseptic loosening in many cases, indicating the clinical significance of this pathogenic mechanism. A variety of implant-, surgery- and host-related factors have been delineated to explain the development of PPOL. These factors influence the development of PPOL because of changes in mechanical stresses within the vicinity of the prosthetic device, excessive wear of the polyethylene liner, and joint fluid pressure and flow acting on the peri-implant bone. The process of aseptic loosening is initially governed by factors such as implant/limb alignment, device fixation quality and muscle coordination/strength. Later, large numbers of wear particles detached from TKA trigger and perpetuate particle disease, as highlighted by progressive growth of inflammatory/granulomatous tissue around the joint cavity. An increased accumulation of osteoclasts at the bone-implant interface, impairment of osteoblast function, mechanical stresses and increased production of joint fluid contribute to bone resorption and subsequent loosening of the implant. In addition, hypersensitivity and adverse reactions to metal debris may contribute to aseptic TKA failure, but should be determined more precisely. Patient activity level appears to be the most important factor when the long-term development of PPOL is considered. Surgical technique, implant design and material factors are the most important preventative factors, because they influence both the generation of wear debris and excessive mechanical stresses. New generations of bearing surfaces and designs for TKA should carefully address these important issues in extensive preclinical studies. Currently, there is little evidence that PPOL can be prevented by pharmacological intervention.