Patients still wish for key improvements after total knee arthroplasty

The Impact of Robotic-Assisted Total Knee Arthroplasty on Resident Training

BACKGROUND

As robotic-assisted total knee replacement (rTKA) continues to gain popularity, the impact of this technology on resident education remains unknown. The purpose of this study was to describe trainee experience and perceptions of rTKA and its effect on surgical training.

METHODS

Two hundred and twenty two senior orthopaedic residents attending a national board review course completed a 17-question survey regarding their experience and perceptions regarding rTKA. Mean and standard deviations were calculated for Likert scale questions, and bivariate analyses were utilized to compare answer groups.

RESULTS

Seventy percent of respondents reported exposure to rTKA during their training. Of those with robotic exposure, 20% reported that greater than half of their TKA experience involved robotics. Only 29% percent agreed that robotics improved outcomes, whereas 21% disagreed and the remainder were unsure. Over half of respondents agreed that robotics are used primarily for marketing purposes. Of those who trained with rTKA, 45% percent believed that robotics improved their understanding of the surgical procedure; however, 25% felt robotics negatively compromised their training with traditional instrumentation. Higher robotic case exposure (P = .001) and attending an industry-sponsored course (P = .02) was associated with the belief that robotics improved outcomes. Robotic case volume and percentage was associated with the belief that robotics improved understanding of the surgical procedure, however, it also was associated with reduced comfort performing traditional knee arthroplasty (P = .001).

CONCLUSION

Current resident training experience varies greatly within the United States with regards to rTKA. While exposure to rTKA may be beneficial for a well-rounded surgical education, over-exposure likely results in decreased comfort with traditional instrumentation.

Comparison of Clinical Outcomes for Patients Treated With Gradually Reducing Radius Versus Single-Radius Total Knee Arthroplasty Systems

The choice of implant used for primary total knee arthroplasty (TKA) may have an impact on clinical outcomes. Clinical outcomes after TKA with gradually reducing radius implants (group G) vs single-radius implants (group S) were evaluated among Asian patients. This study included 541 patients (754 knees) in group G and 187 patients (275 knees) in group S. Range of motion (ROM), flexion contracture, American Knee Society Knee and American Knee Society Function scores (KSKS and KSFS, respectively), and mechanical and anatomic tibiofemoral angles (MTFA and ATFA, respectively) were evaluated with electronic medical records. In univariate analysis, improvements in ROM, KSKS, and KSFS were significantly better in group G compared with group S at 1-year follow-up. Multivariable analyses showed greater ROM (4.52°, P=.002), decreased flexion contracture (-2.80°, P=.011), and improved KSKS (15.57, P<.001) at 1 year for group G vs group S. No significant differences in KSFS, MTFA, or ATFA were observed. Implant-related complications and radiologic loosening were not identified in either group at 2-year follow-up. The TKA implants with a gradually reducing radius showed greater 1-year improvements in ROM, flexion contracture, KSKS, and similar implant-related safety outcomes compared with a single-radius system. [Orthopedics. 2022;45(6):367-372.].

Wound closure position in total knee arthroplasty: flexion versus extension-a meta-analysis of randomized controlled trials

BACKGROUND

Total knee arthroplasty (TKA) is one of the most commonly used procedures in orthopedics. However, whether different would closure positions affect the clinical outcomes after TKA remains controversial. We conducted a meta-analysis of randomized controlled trials (RCT) to assess the effect of wound closure position on clinical TKA outcomes.

METHODS

Embase, PubMed, and the Cochrane Library databases were systematically searched. A systematic review and meta-analysis of all RCTs were performed to prove the role of different wound closure positions on TKA.

RESULTS

Five RCTs containing 389 patients were included. Surgical closure of 90° flexion in TKA was associated with higher post-operative range-of-motion (ROM) at post-operative 4 weeks, lower VAS post-operative pain scores 4 weeks and 3 months, better peak torque difference of flexor muscle strength at 60 and 180°/s angular velocities between the flexion and the extension groups, and better total work difference of flexor muscle strength at 180°/s angular velocity. The American Knee Society Score did not show any significant difference between two closure techniques. No complications were described in the literature review.

CONCLUSIONS

Wound closure in 90° flexion during TKA may provide better postoperative ROM, higher pain relief, preferable muscle strength improvement in short-term follow-up, and no increase in the risks of wound complications.

LEVEL OF EVIDENCE

Level II.

A high degree of knee flexion after TKA promotes the ability to perform high-flexion activities and patient satisfaction in Asian population

Background

This study investigated whether achieving a higher degree of knee flexion after TKA promoted the ability to perform high-flexion activities, as well as patient satisfaction and quality of life.

Methods

Clinical data on 912 consecutive primary TKA cases involving a single high-flexion posterior stabilized fixed-bearing prosthesis were retrospectively analyzed. Demographic and clinical data were collected, including knee flexion angle, the ability to perform high-flexion activities, and patient satisfaction and quality of life.

Results

Of the cases, 619 (68%) achieved > 130° of knee flexion after TKA (high flexion group). Knee flexion angle and clinical scores showed significant annual changes, with the maximum improvement seen at 5 years and slight deterioration observed at 10 years postoperatively. In the high flexion group, more than 50% of the patients could not kneel or squat, and 35% could not stand up from on the floor. Multivariate analysis revealed that > 130° of knee flexion, the ability to perform high-flexion activities (sitting cross-legged and standing up from the floor), male gender, and bilateral TKA were significantly associated with patient satisfaction after TKA, while the ability to perform high-flexion activities (sitting cross-legged and standing up from the floor), male gender, and bilateral TKA were significantly associated with patient quality of life after TKA.

Conclusions

High knee flexion angle (> 130°) after TKA increased the ease of high-flexion activities and patient satisfaction. The ease of high-flexion activities also increased quality of life after TKA in our Asian patients, who frequently engage in these activities in daily life.

Does patient-specific instrumentation increase the risk of notching in the anterior femoral cortex in total knee arthroplasty? A comparative prospective trial

PURPOSE

Patient-specific instrumentation (PSI) was usually applied in total knee arthroplasty (TKA) to acquire a favourable alignment. We hypothesized that using PSI had a potential risk of notching in the anterior femoral cortex, because the femoral component may be placed in an overextension position due to the distal femoral sagittal anteversion. The aim of this study was to figure out the relationship between the notch and the distal femoral sagittal anteversion in PSI-assisted TKA.

METHODS

One hundred thirty-one patients who were to undergo total knee arthroplasty (TKA) were randomly divided into conventional instrumentation (CI) group and PSI group. The computed tomography (CT) data of lower extremities was collected and imported to the Mimics software to reconstruct the three-dimensional (3D) bone image of the femur. The angle between distal femoral anatomic axis (DFAA) and femoral mechanical axis (FMA) on sagittal plane was defined as distal femoral sagittal anteverted angle (DFSAA) and measured. The number of notch intra-operative and post-operative was recorded. Then, we calculated the incidence of the notch and analyzed its relationship with DFSAA.

RESULTS

The average DFSAA of 262 femurs is 2.5° ± 1.5° (range, 0.0°-5.7°). When DFSAA ≥ 3°, the incidence of notch was 7.10% in CI group and 33.30% in PSI group, respectively, which shows significant statistical difference in the two groups (P = 0.016 < 0.05). When DFSAA < 3°, the incidence of notch was 6.50% in CI group and 5.30% in PSI group, respectively, which shows no significant statistical difference in the two groups (P = 0.667 > 0.05).

CONCLUSION

DFSAA could be taken as an indicator to predict the notch when performing TKA assisted with PSI. Especially when the DFSAA ≥ 3°, the risk of notch could be markedly increased.

Effect of an e-Learning Tool on Expectations and Satisfaction Following Total Knee Arthroplasty: A Randomized Controlled Trial

BACKGROUND

Orthopedic surgeons recognize patient expectations of total knee arthroplasty (TKA) can be managed through education. E-learning is the application of educational technology. The objective of this study was to evaluate whether an e-learning tool could affect whether patients' expectations were met and they were satisfied 1 year following TKA.

METHODS

Patients with osteoarthritis from the London Health Sciences Centre, Canada, were randomly assigned to either a control group (n = 207) receiving standard patient education or an intervention group (n = 209) using the e-learning tool in addition to the standard. We used a web-based system with permuted block sizes, stratified by surgeon and first or second TKA. Preoperative measures were completed following the patients' preadmission clinic visit. Postoperative patient-reported outcome measures were completed at 6 weeks, 3 months, and 1 year after TKA. One year after TKA, risk difference was used to determine between-group differences for patient satisfaction and expectations being met.

RESULTS

One year postoperatively, the risk that expectations of patients were not met was 21.8% in the control group and 21.4% in the intervention group for an adjusted risk difference of 1.3% (95% confidence interval, -7.8% to 10.4%, P = .78). The proportion of patients satisfied with their TKA at 1 year postoperative was 78.6% in the intervention and 78.2% in the control groups.

CONCLUSION

There was no between-group difference at 1 year between intervention and control groups for either the risk that expectations of patients were not met or the proportion of patients who were dissatisfied with their TKA.

Higher physical activity and lower pain levels before surgery predict non-improvement of knee pain 1 year after TKA

PURPOSE

The purpose of this study was to describe patterns of pain during the first year following total knee arthroplasty (TKA) and evaluate pre- and postoperative factors associated with pain and patient satisfaction at 1 year. It was hypothesized that more severe preoperative pain would be associated with more residual pain and lower patient satisfaction 1 year after surgery.

METHODS

A longitudinal cohort study was performed with repeated measures of pain (0-10 numeric rating scale) and evaluation of other self-reported symptoms (Hospital Anxiety and Depression Scale, Pittsburgh Sleep Quality Index, and Fatigue Severity Score), daily functioning (Lawton Instrumental Activities of Daily Living Scale), quality of life (EQ-5D-3L), knee function (KSS Knee and Function Score), perioperative and clinical characteristics (e.g. surgery duration, brand of implant, comorbidities), biochemical parameters (haemoglobin, C-reactive protein, creatinine), and patient satisfaction (20-item scale). Post-surgical improvement was defined as at least a two-point decrease in the patient's rating of pain interference with walking from baseline to 1 year. Hundred patients (mean age 64 ± 8 years and 93% female) consecutively admitted for uncomplicated primary TKA participated, and 79 with complete data were included in this analysis.

RESULTS

Pain generally decreased during the first postoperative year, from an average rating of 6 (SD = 3) to 1 (SD = 2). However, 18 of the 79 patients experienced no improvement in pain from baseline to 1 year. Factors associated with non-improvement of pain interference with walking after TKA included lower preoperative ratings of pain interference with walking (p < 0.001) and lower preoperative ratings of average pain (p = 0.004), active or very active levels of preoperative physical activity (p = 0.017), and higher ratings of worst pain on the first three postoperative days (p = 0.028). Pain at 1 year was the only predictor of lower patient satisfaction at 1 year.

CONCLUSIONS

Patients with low preoperative pain ratings or high preoperative levels of physical activity are at increased risk of non-improvement in knee pain after TKA. This finding should be taken into consideration when selecting appropriate candidates for TKA surgery. Orthopaedic surgeons should pay particular attention to patients reporting low pain interference with walking and consider other conservative or surgical treatment options before TKA. Effective strategies for detection and treatment of TKA patients with high pain ratings at early follow-up visits also need to be developed.

LEVEL OF EVIDENCE

Prognostic study, Level II.

Second-generation bi-cruciate stabilized total knee system has a lower reoperation and revision rate than its predecessor

INTRODUCTION

Total knee arthroplasty (TKA) can provide pain relief and good long-term results. However, nearly 30% of post-surgical patients are unsatisfied due to persistent pain and functional deficits. A second-generation bi-cruciate stabilized TKA device has a post-cam mechanism with an asymmetric femoral component, a polyethylene insert, and a medially concave and laterally convex shape. The device is designed to provide guided motion, and thus improve knee kinematics by more closely approximating a normal knee. The aim of this study was to evaluate early complication and revision rates of the second-generation device and to compare its clinical performance to the first-generation device.

MATERIALS AND METHODS

In this retrospective, longitudinal, non-concurrent cohort study, 140 TKAs were performed using the second-generation device on 131 patients from 2012 to 2016, and 155 TKAs were performed using the first-generation device on 138 patients from 2009 to 2012. Primary outcomes were occurrence of revisions and reoperations.

RESULTS

There were 31 reoperations [3.21 per 100 observed component years (OCY)] in 22 (2.28 per 100 OCY) TKAs in the first-generation device cohort compared to five reoperations (1.92 per 100 OCY) in four TKAs (1.54 per 100 OCY) in the second-generation device cohort. The adjusted hazard ratio (HR) was 3.50 (P = 0.0254). There were 21 revisions (2.17 per 100 OCY) in 16 (1.66 per 100 OCY) TKAs in the first-generation device cohort, compared to only three revisions (1.15 per 100 OCY) in two TKAs (0.77 per 100 OCY) in the second-generation device cohort. The adjusted HR was 4.16 (P = 0.0693).

CONCLUSION

The improved design of the second-generation device appears to be associated with a lower risk of reoperation and revision compared to that of the first-generation device.

LEVEL OF EVIDENCE

III.

Patient Dissatisfaction Following Total Knee Arthroplasty: A Systematic Review of the Literature

BACKGROUND

Dissatisfaction following total knee arthroplasty (TKA) is common. Approximately 20% of patients report dissatisfaction following primary TKA. This systematic literature review explores key factors affecting patient dissatisfaction following TKA.

METHODS

Six literature databases published between 2005 and 1 January 2016 were searched using 3 key search phrases. Papers were included if the study investigated patient dissatisfaction in primary unilateral or bilateral TKA. Information from each article was categorized to the domains of socioeconomic, preoperative, intraoperative, and postoperative factors affecting patient dissatisfaction.

RESULTS

This review found that patient dissatisfaction pertains to several key factors. Patient expectations prior to surgery, the degree of improvement in knee function, and pain relief following surgery were commonly cited in the literature. Fewer associations were found in the socioeconomic and surgical domains.

CONCLUSION

Identifying who may be dissatisfied after their TKA is mystifying; however, we note several strategies that target factors whereby an association exists. Further research is needed to better quantify dissatisfaction, so that the causal links underpinning dissatisfaction can be more fully appreciated and strategies employed to target them.

Comparative Effects of Periarticular Multimodal Drug Injection and Single-Shot Femoral Nerve Block on Pain Following Total Knee Arthroplasty and Factors Influencing Their Effectiveness

Purpose

This study compared the analgesic effects of local infiltration analgesia (LIA) and femoral nerve block (FNB) after total knee arthroplasty (TKA) and assessed factors associated with analgesia obtained by these two methods.

Materials and Methods

Study subjects included 66 patients (72 knees) who underwent TKA for osteoarthritis of the knee. Pain visual analogue scale (VAS), the amount of analgesics used, number of days to achieve 90° of flexion of the knee joint, date of initiating parallel-bar walking, range of motion of the knee joint at discharge, and adverse events were investigated.

Results

The VAS scores did not differ significantly between two groups, whereas the amount of analgesics used was significantly lower in the LIA group. Preoperative flexion contracture was significantly more severe in the LIA group with high VAS compared with low VAS. No serious adverse event occurred in the LIA or FNB group.

Conclusions

The lower analgesic usage in the LIA group than the FNB group indicates that the analgesic effect of LIA was greater than that of singleshot FNB after TKA. There were no serious complications in either group. The postoperative analgesic effect of LIA was smaller in patients with severe than less severe preoperative flexion contracture.

In-vivo kinematics of high-flex posterior-stabilized total knee prosthesis designed for Asian populations

PURPOSE

The purpose of this study was to determine in-vivo kinematics of our developed posterior-stabilized (PS) total knee prosthesis for Asian populations in comparison with a popular high-flexion PS prosthesis.

METHODS

We analyzed 62 osteoarthritic knees: 31 knees with the new PS prosthesis (group A) and 31 knees with a popular high-flexion PS prosthesis (group B). Radiographic knee images were taken during standing, lunge, and kneeling activities. The three-dimensional position and orientation of the implant components were determined using model-based shape matching techniques.

RESULTS

Group A showed slightly greater implant flexion angles compared with knees with conventional prosthesis at maximum lunge (average: 119 vs. 110°, p = 0.001), and at maximum kneeling (121 vs. 114°, p = 0.004), although the range of motion was not significantly different. The femoral centre positions were more posterior in group A at standing, at 90° lunge, at maximum lunge (-9 and -7 mm, p = 0.004), at 90° kneeling, and at maximum kneeling (-9 vs. -7 mm, p = 0.016), and posterior translations of the femoral center were greater at 90° knee flexion postures. The femoral centre positions had a strong negative correlation with implant flexion angles at maximum lunge in group B (r = -0.893, p < 0.001), but not in group A (p = 0.242).

CONCLUSIONS

The new PS prosthesis designed for Asian knee morphology achieved flexion angles and range of motion at least comparable to that of conventional high-flexion PS prosthesis. The femoral roll-back pattern, however, is different from a conventional knee, reflecting the post/cam design.

Patient Satisfaction after Total Knee Arthroplasty

Total knee arthroplasty (TKA) is one of the most successful and effective surgical options to reduce pain and restore function for patients with severe osteoarthritis. The purpose of this article was to review and summarize the recent literatures regarding patient satisfaction after TKA and to analyze the various factors associated with patient dissatisfaction after TKA. Patient satisfaction is one of the many patient-reported outcome measures (PROMs). Patient satisfaction can be evaluated from two categories, determinants of satisfaction and components of satisfaction. The former have been described as all of the patient-related factors including age, gender, personality, patient expectations, medical and psychiatric comorbidity, patient's diagnosis leading to TKA and severity of arthropathy. The latter are all of the processes and technical aspects of TKA, ranging from the anesthetic and surgical factors, type of implants and postoperative rehabilitations. The surgeon- and patient-reported outcomes have been shown to be disparate occasionally. Among various factors that contribute to patient satisfaction, some factors can be managed by the surgeon, which should be improved through continuous research. Furthermore, extensive discussion and explanation before surgery will reduce patient dissatisfaction after TKA.

Serial Changes of Quadriceps and Hamstring Muscle Strength Following Total Knee Arthroplasty: A Meta-Analysis

This meta-analysis was performed to analyze serial changes in thigh muscles, including quadriceps and hamstring muscles, from before to one year after total knee arthroplasty (TKA). All studies sequentially comparing isokinetic quadriceps and hamstring muscle strengths between the TKA side and the contralateral uninjured limb were included in this meta-analysis. Five studies with 7 cohorts were included in this meta-analysis. The mean differences in the strengths of quadriceps and hamstring muscles between the TKA and uninjured sides were greatest three months after surgery (26.8 N∙m, 12.8 N∙m, P<0.001), but were similar to preoperative level at six months (18.4 N∙m, 7.4 N∙m P<0.001) and were maintained for up to one year (15.9 N∙m, 4.1 N∙m P<0.001). The pooled mean differences in changes in quadriceps and hamstring strengths relative to preoperative levels were 9.2 N∙m and 4.9 N∙m, respectively, three months postoperatively (P = 0.041), but were no longer significant after six months and one year. During the year after TKA, quadriceps and hamstring muscle strengths were lowest after 3 months, recovering to preoperative level after six months, but not reaching the muscle strength on the contralateral side. Relative to preoperative levels, the difference in muscle strength between the TKA and contralateral knees was only significant at three months. Because decrease of strength of the quadriceps was significantly greater than decrease in hamstring muscle strength at postoperative three months, early rehabilitation after TKA should focus on recovery of quadriceps muscle strength.