Patient satisfaction after total knee arthroplasty is affected by their general physical well-being

A clinical risk score enables early prediction of dissatisfaction 1 year after total knee arthroplasty

PURPOSE

Dissatisfaction after total knee arthroplasty (TKA) is a prevalent and clinically relevant problem that affects approximately 10%-20% of patients. The aim of this study is to identify factors associated with dissatisfaction 1 year after TKA.

METHODS

A total of 236 patients undergoing TKA were included in this prospective cohort study. Demographic data, preoperative clinical parameters (e.g., axial alignment, osteoarthritis severity) and patient-reported outcome measures (PROMs) were collected preoperatively, at 1 month and 1 year after TKA, encompassing the Knee Society Score (KSS) and Knee injury and Osteoarthritis Outcome Score (KOOS). The primary outcome was dissatisfaction 1 year after TKA, defined as ≤20 points on the KSS satisfaction scale. A risk score based on multiple regression and area under the curve (AUC) analyses was calculated to predict dissatisfaction.

RESULTS

One year after TKA, 16% of the patients were dissatisfied. Dissatisfied patients were significantly younger (p = 0.023) and had a higher body mass index (BMI) (p = 0.007). No differences were observed in preoperative objective (p = 0.903) and functional KSS (p = 0.346), pain (p = 0.306), osteoarthritis severity (p = 0.358), axial knee alignment (p = 0.984) or psychological distress (p = 0.138). The likelihood of dissatisfaction at 1 year was 3.0, 4.0, 7.4, 4.3 and 2.8 times higher amongst patients aged <63.5 years, with a BMI > 30.1 kg/m2, a KOOSPain < 50%, a KSSFunction < 42 points and a KSSExpectation < 9 points (all at 1 month), respectively. Using these variables, a risk score with a maximum of 7 points was developed, demonstrating a high predictive value for dissatisfaction (AUC: 0.792 [95% confidence interval: 0.700-0.884], p < 0.001).

CONCLUSION

Dissatisfaction 1 year after TKA can be predicted by a weighted risk score that includes patient age, BMI, pain, subjective functionality and unmet expectation 1 month postoperatively. Using the risk score, early detection of dissatisfaction has the potential to enable targeted interventions and improve patients' quality of life.

LEVEL OF EVIDENCE

Level II, Prognostic study.

Sequential bilateral total ankle replacements: No difference in patient-reported outcomes between the first and second ankle

BACKGROUND

Total ankle replacement is an established treatment for end-stage arthritis. However, there is little data examining outcomes in sequential bilateral replacements. This study aimed to compare outcomes between first and second ankles in sequential replacement.

METHODS

Patients were retrospectively contacted to complete a follow-up questionnaire including the Manchester-Oxford Foot Questionnaire (MOXFQ), EQ-5D-3 L, and a question assessing satisfaction. Electronic records identified demographics, procedural details, and complications.

RESULTS

Twenty patients underwent sequential bilateral ankle replacement over the study period. At a mean follow-up of four years, 18 patients completed the follow-up questionnaire. There was no statistically significant difference between first and second ankles in terms of MOXFQ score, EQ-5D-3 L or satisfaction. Eleven complications were noted.

CONCLUSIONS

We report excellent outcomes after sequential bilateral ankle replacement with no difference in outcomes between first and second ankles. These results can be used to counsel patients in the future and manage expectations.

LEVEL OF EVIDENCE

IV.

Mental Health Effects on the Minimal Clinically Important Difference in Total Joint Arthroplasty

INTRODUCTION

The effect of mental health on patient-reported outcome measures is not fully understood in total joint arthroplasty (TJA). Thus, we investigated the relationship between mental health diagnoses (MHDs) and the Minimal Clinically Important Difference for Improvement (MCID-I) and Worsening (MCID-W) in primary TJA and revision TJA (rTJA).

METHODS

Retrospective data were collected using relevant Current Procedural Terminology and MHDs International Classification of Diseases, 10th Revision, codes with completed Hip Disability and Osteoarthritis Outcome Score-Physical Function Short Form, Knee Injury and Osteoarthritis Outcome Score-Physical Function Short Form, Patient-reported Outcomes Measurement Information System (PROMIS)-Physical Function Short Form 10a, PROMIS Global-Mental, or PROMIS Global-Physical questionnaires. Logistic regressions and statistical analyses were used to determine the effect of a MHD on MCID-I/MCID-W rates.

RESULTS

Data included 4,562 patients (4,190 primary TJAs/372 rTJAs). In primary total hip arthroplasty (pTHA), MHD-affected outcomes for Hip Disability and Osteoarthritis Outcome Score-Physical Function Short Form (MCID-I: 81% versus 86%, P = 0.007; MCID-W: 6.0% versus 3.2%, P = 0.008), Physical Function Short Form 10a (MCID-I: 68% versus 77%, P < 0.001), PROMIS Global-Mental (MCID-I: 38% versus 44%, P = 0.009), and PROMIS Global-Physical (MCID-I: 61% versus 73%, P < 0.001; MCID-W: 14% versus 7.9%, P < 0.001) versus pTHA patients without MHD. A MHD led to lower rates of MCID-I for PROMIS Global-Physical (MCID-I: 56% versus 63%, P = 0.003) in primary total knee arthroplasty patients. No effects from a MHD were observed in rTJA patients.

DISCUSSION

The presence of a MHD had a prominent negative influence on pTHA patients. Patients who underwent rTJA had lower MCID-I rates, higher MCID-W rates, and lower patient-reported outcome measure scores despite less influence from a MHD.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Local Periarticular Infiltration with Dexmedetomidine Results in Superior Patient Well-Being after Total Knee Arthroplasty Compared with Peripheral Nerve Blocks: A Randomized Controlled Clinical Trial with a Follow-Up of Two Years

BACKGROUND

This study aimed to compare local periarticular infiltration (LIA) with ultra-sound guided regional anesthesia (USRA) with ropivacaine and dexmedetomidine as an additive agent in primary total knee arthroplasty (TKA).

METHODS

Fifty patients were randomized into two groups in a 1:1 ratio. Patients in the LIA group received local periarticular infiltration into the knee joint. The USRA group received two single-shot USRA blocks. Functional outcomes and satisfaction (range of movement, Knee Society Knee Score, Western Ontario and McMaster Universities Osteoarthritis Index, Oxford Knee Score, and Forgotten Joint Score), including well-being, were analyzed preoperatively and at five days, six weeks, and one and two years postoperatively.

RESULTS

Functional outcomes did not significantly differ between the two groups at six weeks and one and two years after the implementation of TKA. A moderate correlation was observed in the LIA group regarding well-being and pain on day five. Six weeks postoperatively, the LIA group showed significantly superior well-being but worse pain scores. No differences between the groups in well-being and functional outcomes could be observed one and two years postoperatively.

CONCLUSION

Patients treated with LIA had superior postoperative well-being in the early postoperative phase of up to six weeks. Furthermore, LIA patients had similar functionality compared to patients treated with USRA but experienced significantly more pain six weeks postoperatively. LIA leads to improved short-term well-being, which is potentially beneficial for faster knee recovery. We believe that LIA benefits fast-track knee recovery with respect to improved short-term well-being, higher practicability, and faster application.

Change in Pain During Physical Activity Following Total Knee Arthroplasty: Associations With Improved Physical Function and Decreased Situational Pain Catastrophizing

Background and Objectives

Knee osteoarthritis is one of the primary causes of chronic pain among older adults and because of the aging population, the number of total knee arthroplasties (TKAs) performed is exponentially increasing. While pain reduction is a goal of TKA, movement-evoked pain is rarely assessed pre- and post-TKA. We characterized the distributions of change in pain, function, and situational catastrophizing in patients from presurgery to 3 months postsurgery and explored associations among these pre-post changes.

Research Design and Methods

This prospective study longitudinally assessed movement-evoked pain, function, and situational catastrophizing in patients with knee osteoarthritis (N = 92) using in-person performance-based tests (6-min walk test [6MWT], stair-climb test [SCT]) prior to and 3 months after TKA. Patients also completed the Western Ontario McMaster Universities Scales (WOMAC) pain and function subscales, and Pain Catastrophizing Scale, presurgery and 3- and 6-months postsurgery.

Results

Movement-evoked pain and function on performance tests significantly improved from pre- to post-TKA. Improved SCT function was associated with reduced SCT pain and catastrophizing. Similarly, reduced pain during the SCT was associated with reduced catastrophizing during the SCT. However, 6MWT function was not associated with 6MWT pain or catastrophizing; yet reduced pain during the 6MWT was associated with reduced catastrophizing during the 6MWT. Reduced movement-evoked pain during both performance tests was consistently associated with improved WOMAC function and pain, whereas improved function on performance tests was inconsistently associated with WOMAC function and pain. Notably, greater movement-evoked pain on both performance tests at 3-month post-TKA was associated with worse WOMAC function and pain at 6 months, whereas better function on performance tests at 3 months was associated with better WOMAC function, but not related to WOMAC pain at 6 months.

Discussion and Implications

Findings highlight the importance of situation-specific and in vivo assessments of pain and catastrophizing during physical activity.

Cross-sectional Analysis Study Between SIGMA Knee System and ATTUNE in a Cruciate-Retaining Fixed-Bearing Total Knee Replacement, with no Patellar Resurfacing

Background

The purpose of our study was to compare the knee implant SIGMA to the ATTUNE knee implant in a cruciate-retaining (CR) fixed-bearing (FB) total knee replacement (TKR) surgery, with no patellar resurfacing.

Methods

We examined 40 patients (19 SIGMA; 21 ATTUNE) who underwent a TKR FB CR surgery, without patellar resurfacing, due to osteoarthritis, between August 2013 and July 2017. All surgeries were performed by a single surgeon. We performed a cross-sectional analytical study based on preoperative patient data and data collected in follow-up sessions. All patients were asked to fill a quality-of-life (QOL) questionnaire, SF-36 translated to the Hebrew language. All patients were clinically evaluated using the Knee Society Score (KSS) and the Knee Function Score (KFS).

Results

Patients from the SIGMA cohort reported fewer postoperative physical function limitations in the SF-36 (p = 0.01) and the KFS (p = 0.04). Patients who underwent surgery using the SIGMA implant reported increased vitality when compared to the ATTUNE (p = 0.02). No significant differences were found between the groups in other measures of quality of life, ranges of motion, valgus, and postoperative knee stability. The average follow-up period was significantly longer for the SIGMA (p < 0.00001).

Conclusion

Significant differences were found in postoperative physical function and vitality scores between SIGMA and ATTUNE knee implants. SIGMA cohort presented superior results. Presumably, these findings are due to the differences in follow-up times.

Are 20% of Patients Actually Dissatisfied Following Total Knee Arthroplasty? A Systematic Review of the Literature

BACKGROUND

Total knee arthroplasty (TKA) is among the most performed orthopaedic surgeries in the United States with at least 1,000,000 cases performed per year. Dissatisfaction following TKA has often been reported as 20% or more, with a multitude of causes including sociodemographic, preoperative, and postoperative factors. The purpose of this study was to re-examine the rate and causes of dissatisfaction following TKA.

METHODS

A systematic review of the literature was performed searching databases from 2010 to 2022. Only primary TKA cases were included and all cases of unicompartmental arthroplasty and revisions were excluded. After abstracts were reviewed, 35 articles were selected for a full-length review, which was ultimately reduced to 21 articles for final inclusion.

RESULTS

The average rate of patient dissatisfaction was 10%. Excluding complications, the average rate of dissatisfaction was 7.3%. The most common sociodemographic factors for dissatisfaction were age < 65 years, lower income, and non-White patients. Preoperative factors included lower Kellgren-Lawrence scores, depression/anxiety, and pain catastrophizing. Postoperatively, most dissatisfaction was due to complications, unmet expectations, persistent pain, and stiffness.

CONCLUSION

Based on our review, the average rate of patient dissatisfaction following TKA is 10%. Improved counseling for known risk factors may have reduced dissatisfaction rates by increasing preoperative patient optimization. Many studies in recent years have demonstrated the issue of poor patient coping skills, such as pain catastrophizing and anxiety/depression as a common cause of dissatisfaction. Ultimately, dissatisfaction following TKA still continues to affect a high portion of patients but less than historical reports of 20%.

The use of an individualized intraoperative video shows no impact on the early postoperative clinical outcome after total knee arthroplasty: a prospective, randomized, controlled trial

PURPOSE

The purpose of the study was to evaluate the potential of an intraoperatively recorded video shown to patients immediately postoperatively on early outcome after total knee arthroplasty (TKA). The hypothesis was that there is a beneficial outcome concerning range of motion (ROM) and patient-reported outcome due to enhanced trust into the artificial joint.

METHODS

Seventy-three patients were randomly assigned 1:1 to two study groups in which they were either shown a video of their own postoperative range of motion or they were not. Clinically, the New Knee Society Score (nKSS) and ROM were evaluated and compared between the groups 6 weeks after surgery. Chi-square exact test, Kolmogorov-Smirnov test, Mann-Whitney U test, and the Wilcoxon signed rank test were used. Inter- and intra-class correlations were calculated for measurements of ROM.

RESULTS

No clinically relevant differences were observed preoperatively and 6 weeks postoperatively between both groups in range of motion (ROM). All patients were showing a significantly improved clinical outcome 6 weeks after the procedure. Clinical scores showed statistically significant differences with respect to preoperative nKSS for satisfaction and statistically significant differences with respect to postoperative nKSS for function.

CONCLUSION

Showing a video filmed immediately after implantation of primary TKA had no significant effect on ROM and clinical outcome at 6 weeks. We believe that face-to-face verbal communication in combination with video-assisted education ensures that patients understand their artificial joint in the best possible way and will continue to use intraoperatively filmed videos to enhance patient engagement during postoperative rehabilitation.

LEVEL OF EVIDENCE

I.

Preoperative Anemia Is Associated With Worse Joint-Specific Postoperative Outcomes, but Is Not Associated With Health-Related Quality of Life or Patient Satisfaction After Total Knee Arthroplasty

BACKGROUND

The primary aim assessed whether preoperative anemia was associated with a worse knee-specific functional outcome after total knee arthroplasty (TKA). The secondary aims assessed the association of preoperative anemia with generic health and patient satisfaction.

METHODS

A retrospective cohort study was undertaken to compare patients who did and did not have anemia (Hb <13.0 g/dL for men and Hb <11.5 g/dL for women). During a 1-year period, 497 patients underwent a total knee arthroplasty with complete preoperative and postoperative data, including 215 (43.3%) men and 282 (56.7%) women, who had a mean age of 70 years (range 45-93). Patient demographics, comorbidities, preoperative and postoperative (1 year) Oxford Knee Score (OKS), EuroQol 5 dimension (EQ-5D), postoperative Forgotten Joint Score (FJS), and patient satisfaction were collected. Regression analyses were used to adjust for confounding factors between the groups.

RESULTS

The 56 (11.3%) patients who had anemia were older (4.6 years, P < .001) and more likely to have chronic obstructive pulmonary disease (P = .004), connective tissue (P = .047), or kidney disease (P = .011) compared to those who did not have anemia. There were no differences in the preoperative OKS (P = .752) or EQ-5D (P = .762) scores between the groups. When adjusting for confounding differences, there was a significantly lower postoperative OKS (-3.0 points, P = .035) and FJS (-11.6 points, P = .011) associated with the anemia group. There were no significant differences in the EQ-5D (P = .118) or patient satisfaction between groups (odds ratio 0.84, P = .976).

CONCLUSION

Preoperative anemia is associated with a lower postoperative joint-specific functional outcome. It is not clear if these differences are clinically meaningful. No difference in patient satisfaction was observed.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Predictors of Patient Satisfaction in Hallux Valgus Surgery

This study aims to analyze a combination of preoperative biodata, radiological parameters, and validated functional scores to determine predictors for patient satisfaction in patients who have undergone Hallux abducto valgus (HAV) surgery at 2 years postoperatively. Data from 288 patients who had undergone HAV surgery and 373 cases were collected between 2007 and 2013. The study group measured the HAV angle (HVA), tibial sesamoid position (TSP), as well as inter-metatarsal angle (IMA) on both pre- and postoperative radiographs for all patients. Clinical outcomes such as the Visual Analogue Scale for pain, the American Orthopaedic Foot and Ankle Society (AOFAS) Hallux Metatarsophalangeal-Interphalangeal Scale (MTP-ITP) Scale, and Short Form 36 Health Survey's physical and mental component scores (PCS and MCS) were captured preoperatively and postoperatively. Univariate analysis was performed first to determine possible predictors of patient satisfaction and the results were then included in a binary logistic regression model. Independent predictors of patient satisfaction include higher preoperative AOFAS (p value = .028, 95% confidence interval [CI] 0.958, 0.998) and the 2 years postoperative AOFAS (p = .001, 95% CI 1.027, 1.114). We also found PCS and MCS scores at 2 years postoperatively to be independent predictors of patient satisfaction (p = .004, 95% CI 1.015, 1.086 and p = .045, 95% CI 1.001, 1.064 respectively). Predictors of patient satisfaction include subjective outcomes such as the AOFAS score and the Short Form 36 composite quality of life scales of PCS and MCS, rather than objective radiological outcomes such as HVA, IMA, and TSP.

Equivalent outcomes of ultra-congruent and standard cruciate-retaining inserts in total knee arthroplasty

PURPOSE

No systematic review has compared the clinical outcome of anterior stabilized ultra-congruent and standard cruciate-retaining inserts in fixed-bearing primary total knee arthroplasty. This study aimed to compare the outcomes and establish the superiority or equivalence of these inserts.

METHODS

Pubmed, EMBASE, Medline, AMED, ERIC, and Proquest databases were searched electronically. PRISMA guidelines were followed in the conduct of the study. The clinical outcomes compared in the meta-analysis were overall knee score, WOMAC, score for knee function, score for knee pain, SF-12 PCS, knee flexion, manipulation under anaesthesia for postoperative knee stiffness, revision total knee arthroplasty or change of polyethylene insert for post-operative instability (relative risk [RR]) and survivorship. Study quality was evaluated using the Newcastle Ottawa Scale and the Modified Jadad scale.

RESULTS

Fourteen studies comprising 9989 knees (three RCTs and 11 comparative case-cohort studies) were included for qualitative and quantitative analysis. The pooled analysis of the ultracongruent insert and the standard cruciate retaining insert was based on a cohort of 2860 and 7129 TKA, respectively. Knee pain was significantly better in patients that had standard inserts (p = 0.02; 95% CI - 1.06 to - 0.10), and the physical component of health-related quality of life was also significantly better in patients that had standard inserts (p = 0.02; 95% CI - 6.43 to - 0.64). There was a 72% lesser chance of revision TKA or change of insert for postoperative instability in knees that had been implanted with ultracongruent inserts (RR = 0.28; p = 0.0002; 95% CI 0.15-0.55). There was no difference in the otheroutcome measures. There was no significant difference between the two inserts, considering the minimal clinically important difference or absolute ratio.

CONCLUSION

Differences observed between the two types of inserts were not clinically significant. Therefore, based on current evidence, arthroplasty surgeons can use either of these inserts with cruciate-retaining knee prosthesis.

LEVEL OF EVIDENCE

Therapeutic study, Level II.

Comparison of the clinical and patient-reported outcomes between medial stabilized and posterior stabilized total knee arthroplasty: A systematic review and meta-analysis

BACKGROUND

Total knee arthroplasty (TKA) is effective in relieving pain and improving function in patients with end-stage knee osteoarthritis. Both medial stabilized total knee arthroplasty (MS-TKA) and posterior stabilized total knee arthroplasty (PS-TKA) can achieve satisfactory clinical results, but comparisons between MS-TKA and PS-TKA have yielded contradictory conclusions. This systematic review and meta-analysis were performed to investigate the differences in clinical and patient-reported outcomes (PROMs) between MS-TKA and PS-TKA.

METHODS

In December 2020, systematic searches of the following databases were undertaken: Pubmed, Embase, Cochrane Library, Clinical Trials.gov. Studies with PROMs comparing MS-TKA to PS-TKA were included. Meta-analysis was conducted for range of motion (ROM), Knee Society Score (KSS), Knee Society Functional Score (KFS), Forgotten Joint Score (FJS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Oxford Knee Score (OKS).

RESULTS

There were 17 studies included in this review, 13 studies used for quantitative analysis, and 4 studies used for qualitative synthesis. Meta-analysis concluded that the WOMAC mean difference (MD) for MS-TKA was 1.55 higher than for PS-TKA (MD = -1.55; 95 %CI = -2.45 to -0.64, P = 0.0008); however, this difference was less than the minimum clinically important difference (MCID) value of 15. Assessment using the OKS determined that the MD for PS-TKA was 0.58 higher than for MS-TKA (MD = 0.58; 95 %CI = 0.25 to 0.91, P = 0.0006); again, this MD was less than the MCID value of 5. There were no significant differences between MS-TKA and PS-TKA when assessed by ROM (P = 0.23), KSS (P = 0.13), KFS (P = 0.61), or FJS (P = 0.22).

CONCLUSION

Derived from numerous sources, utilizing a multitude of validated functional and patient-reported outcome assessment tools, there was no clinically evident advantage of MS-TKA compared to PS-TKA.

REGISTRATION

The registration number on PROSPERO is CRD42021228555.

Depression Is Not Independently Associated with a Clinically Worse Functional Improvement but Associated with a Lower Reported Satisfaction Rate after Total Knee Arthroplasty

The aim of this study was to assess whether depression had a clinically significant influence on the functional improvement of total knee arthroplasty (TKA) according to the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, and whether it influences patient satisfaction at 1 year. A retrospective cohort of 3,510 primary TKA was identified from an arthroplasty database. Patient demographics, comorbidities, WOMAC, and Short Form-12 (SF-12) scores were collected preoperatively and 1 year postoperatively. Patient satisfaction (overall, pain relief, return to work, and recreational activity) was assessed at 1 year. There were 444 (12.6%) patients who self-reported depression. Patients with depression were younger (p < 0.001), had a higher body mass index (BMI; p < 0.001), were more likely to be female (p < 0.001), had lung (p < 0.001), neurological (p = 0.018), kidney (p = 0.001), liver (p < 0.001), and gastric (p < 0.001) disease, report associated diabetes (p = 0.001), and back pain (p < 0.001) relative to the subgroup without depression. All preoperative WOMAC functional measures were significantly (p < 0.001) worse in patients with reported depression. When adjusting for these confounding differences, patients with depression had a clinically equal improvement in their WOMAC scores at 1 year compared to those patients without. Depression was not associated with a clinically significant difference in improvement of knee-specific outcome (WOMAC) but was independently associated with a lower rate of patient satisfaction 1 year after TKA. Patients with depression were approximately twice as likely to be dissatisfied at 1 year when compared with those without depression. This is a prognostic retrospective cohort study and reflects level of evidence III.

Negative Association of Subclinical Hypothyroidism on Improvement in Patient-Reported Outcomes After Total Knee Arthroplasty

BACKGROUND

The purpose of this study is to analyze the potential influence of subclinical hypothyroidism (SCH) on improvement in patient-reported outcome measures following primary total knee arthroplasty.

METHODS

A prospective, comparative cohort study between 92 SCH and 90 euthyroid patients was performed. Patients were followed up to 5 postoperative years. Patient-reported outcome measure was assessed by the Western Ontario and McMaster Universities Osteoarthritis Index questionnaire. The Knee Society Scores were used for functional evaluation, and 5-point Likert scale for patient satisfaction. The Hospital Anxiety and Depression scale was also used.

RESULTS

All outcome scores significantly improved from preoperative to final follow-up in both groups (P = .001). There were no significant differences between groups in Knee Society Scores (P = .057) at the final follow-up, but Western Ontario and McMaster Universities Osteoarthritis Index scores were significantly lower in the SCH group (P = .015). Likewise, the patient satisfaction rate was significant lower in the SCH group (0.010).

CONCLUSION

SCH patients have a slower functional recovery than euthyroid patients, and trended toward lower improvements in patient-reported scores. Depression was the most important negative factor. The findings of this study can provide the surgeon with an important information for better counseling the SCH patients.

Midterm functional recovery of Total knee arthroplasty patients compared between the ATTUNE knee system and the press fit condylar (PFC) SIGMA knee system

BACKGROUND

The ATTUNE Knee System is a new prosthetic design that has theoretical advantages over the Press Fit Condylar (PFC) Sigma Knee System specific to improved knee kinematics and patellofemoral joint tracking. This study aimed to evaluate functional outcomes compared between the ATTUNE and PFC Sigma designs at a minimum follow-up of 5 years.

METHODS

We retrospectively reviewed data from total knee arthroplasty (TKA) patients who received either the ATTUNE or PFC Sigma system during November 2013 to February 2015 at Siriraj Hospital (Bangkok, Thailand). Functional outcomes were evaluated using Timed Up and Go (TUG) test, 2-min walk test (2MWT), modified knee score, numerical rating scale-pain, range of motion (ROM), and rate of anterior knee pain and crepitation at preoperation, 3-months, 1-year, and 5-years postoperatively.

RESULTS

Of 113 patients, 59 and 54 received the PFC Sigma and ATTUNE systems, respectively. At a minimum of 5-years follow-up, all functional outcomes improved significantly from the preoperative period although TUG test and 2MWT declined significantly from 1- to 5-years postoperatively only in the PFC Sigma group. The mean ROM at 5-years postoperatively was significantly higher in ATTUNE than in PFC Sigma; however, the difference was small (116° vs. 110°, respectively; p = 0.041). There were no significant differences in any of the other outcome measurements, including anterior knee pain, clunking, and crepitation, between groups at any study time point.

CONCLUSIONS

​Our results revealed no major differences in functional outcomes between the PFC Sigma and ATTUNE TKA designs at an intermediate-term follow-up of at least 5 years. Longer-term follow-up study is needed to evaluate the benefits of the ATTUNE design relative to polyethylene wear and the rate of aseptic loosening.

Oxford Knee Score and EQ-5d poorly predict patient's satisfaction following mechanically aligned total knee replacement: A cross-sectional study

BACKGROUND

Patient satisfaction is increasingly used to measure the success of arthroplasty. Satisfaction with the outcome of a total knee replacement (TKR) is traditionally thought to be associated with improvements in functional status and quality of life measures. This study aims to answer the following questions: 1. What is the level of patient satisfaction, improvement in knee function and patient quality of life associated with mechanically aligned TKR? 2. What is the relationship between OKS, EQ-5d scores and 'outcome satisfaction'?

HYPOTHESIS

TKR is associated with a significant improvement in function, satisfaction and quality of life and that there is a strong correlation between OKS, EQ-5d and 'outcome satisfaction'.

METHOD

Five thousand eight hundred and ninety six patients underwent primary TKR between January 2010 and December 2017 and had complete preoperative and 2-year follow-up data for OKS, EQ-5d and satisfaction scores. Outcomes data were collected prospectively and recorded on our institutional database. Minimal clinically important difference (MCID) and the Patient acceptable symptomatic state (PASS) were calculated for OKS and EQ-5d, the association between OKS, EQ-5d and 'outcome satisfaction' was measured using regression analysis.

RESULTS

The median 2-year 'outcome satisfaction' score was 90/100 with 79% of patients reporting excellent satisfaction (≥80/100) and 93.4% of patients satisfied (≥50/100). Postoperatively, median scores were 39 for OKS and 0.8 for EQ-5d. The mean increase in scores was 15.85 for OKS and 0.32 for EQ-5d. Satisfaction showed moderate positive correlation with postoperative OKS (r=0.69) and EQ-5D (0.58) scores, but weaker correlation with the change in OKS (r=0.57) and EQ-5d (r=0.32) scores from preoperative levels.

DISCUSSION/CONCLUSION

Mechanically aligned TKR is overall a successful operation responsible of fair rate of patient satisfaction. OKS and EQ-5d are imperfect predictors for satisfaction as they are significantly influenced by patients' comorbidities. This should be taken into account when evaluating the success of an operation.

LEVEL OF EVIDENCE

IIc; observational study (based on prospectively collected data from an institutional registry).

Validation of a Patient Questionnaire Assessing Patient Satisfaction With Orthopedic Outpatient Clinic Consultation

Previous qualitative research has identified a number of factors which influence patient satisfaction with orthopedic outpatient clinic visits. To further evaluate these factors, the authors initially generated a number of items or statements representing these factors. This cohort of items was then subjected to analysis by an expert group to assess which 3 items best represented each factor. These items formed the basis of a draft survey which was then administered to 323 orthopedic outpatients to assess these factors as characteristics of patient satisfaction. Items and factors were also assessed against 2 global measures of patient satisfaction. One hundred and one survey responses were returned and subjected to factorial analysis. Results indicated that factors of trust, empathy, and relatedness were not distinguishable and subsequently combined to represent a single factor, the therapeutic relationship. A final 5-factor model is proposed incorporating 3 interpersonal factors (communication, expectation, therapeutic relationship) and 2 environmental factors (clinic wait time, clinical contact time). The factors identified by this study should be considered in surveys evaluating patient satisfaction with orthopedic outpatient services.

Differences in patient-reported outcomes between medial opening-wedge high tibial osteotomy and total knee arthroplasty

PURPOSE

To compare patient subjective satisfaction between medial opening-wedge high tibial osteotomy (HTO) and total knee arthroplasty (TKA).

METHODS

This study enrolled 110 knees, including comprising 49 knees in the HTO group, and 61 knees in the TKA group. We assessed the overall satisfaction using a three-point questionnaire. The satisfaction questionnaire included three questions: (1) How satisfied are you with the results of your knee surgery? (2) How satisfied are you with your most recent knee surgery for reducing your pain? and (3) How satisfied are you with your most recent knee surgery for improving your ability to perform functions? Furthermore, we assessed knee pain and function by using the Knee Society Function Score (KSS) and Knee Injury and Osteoarthritis Outcome Score (KOOS) systems.

RESULTS

Overall, 93.8% of patients from the HTO group and 95.1% from the TKA group indicated subjective satisfaction (very satisfied and satisfied) with their surgeries. For pain relief, the HTO group showed significantly better outcomes for overall satisfaction (p = 0.04 in walking on a flat surface and p = 0.02 in going upstairs or downstairs). For restored function, the HTO group scored significantly better on ascending stairs than the TKA group (p = 0.007). Functional outcomes using the KSS scoring system did not show significant differences between the two groups. The KOOS pain score was significantly higher in the TKA group (89.9 ± 6.4) than in the HTO group (80.3 ± 12.5).

CONCLUSION

HTO and TKA have comparable outcomes with respect to overall patient satisfaction.

LEVEL OF EVIDENCE

Level III, therapeutic case series.

Clinical Outcomes of a Modern Total Knee Arthroplasty Prosthesis Compared to Its Predecessor at 5-Year Follow-Up: Matched Pair Analysis

BACKGROUND

Residual pain is an important cause of patient dissatisfaction after total knee arthroplasty (TKA). A recent study at our institution found that a modern prosthesis was associated with less residual and anterior knee pain at 2-year follow-up when compared to its predecessor. The aim of this study is to evaluate these implants at 5-year follow-up.

METHODS

From July 2012 to December 2013, 100 consecutive modern TKAs were identified from our prospective Institutional Review Board approved database. All patients with 5-year clinical follow-up (n = 77) were matched in a one-to-one fashion based on age, gender, body mass index, and follow-up with a predecessor TKA. Clinical outcomes were assessed with a patient-administered questionnaire for specifically anterior knee pain, painless noise, painful crepitation, and satisfaction. Overall function was assessed using Knee Society Scores and Western Ontario and McMaster University Osteoarthritis Index.

RESULTS

At 5-year follow-up, there were no significant differences between the modern TKA and a predecessor TKA in the Knee Society pain or function scores (P = .24 and P = .54, respectively). The overall prevalence of residual pain was less with the modern TKA compared to its predecessor (19.5% vs 36.3%; P = .02), but the prevalence of isolated anterior knee pain was similar in both cohorts (11.7% vs 22.1%; P = .09). There was no difference in painless noise (19.5% vs 13.3%; P = .28) or satisfaction scores (7.9 ± 2.4 vs 7.6 ± 2.6; P = .25) between the modern and predecessor cohorts.

CONCLUSION

At 5-year follow-up, we found that both the modern and predecessor prostheses provided excellent clinical outcomes. The modern TKA was associated with less residual pain compared to its predecessor, but we were unable to detect differences in the prevalence of isolated anterior knee pain, painless noise, Knee Society Scores, or radiographic evaluation.

Dual Mobility Bearing Articulations Result in Lower Rates of Dislocation After Revision Total Hip Arthroplasty

INTRODUCTION

The purpose of our study is to directly compare the rates of instability after revision total hip arthroplasty (THA) between a modular dual mobility (DM) and a conventional polyethylene single-bearing surface.

METHODS

We retrospectively reviewed a consecutive series of patients who underwent revision THA from 2012 to 2016 at a single institution with a minimum of 2 years of follow-up. Rates of re-revision, dislocation, complications, and short-form (SF-12) scores were compared between the DM and single-bearing groups. To control for confounding variables, a multivariate logistic regression analysis was performed.

RESULTS

Of the 267 revision THA patients, 94 patients had a DM bearing articulation (36%), whereas 173 patients (64%) had a conventional single-bearing with a mean follow-up of 37.8 months (range 24 to 73 months). The DM group was more likely to undergo revision THA for instability compared with the single-bearing group (8.5% versus 1.2%, P ≤ 0.005) but had reduced incidence of postoperative dislocations (2.1% versus 8.7%, P = 0.067) and no difference in the rates of re-revisions (9.6% versus 11.6%, P = 0.770). When controlling for confounding variables, patients who received a DM liner had lower rates of dislocation postoperatively than those of single-bearing (odds ratio 0.12, P = 0.019).

DISCUSSION

Even with a selection bias of surgeons using DM for patients at high risk of instability, patients undergoing revision THA with a DM bearing have reduced rates of dislocation at the intermediate-term follow-up. Further study is needed to identify any potential longer-term complications which may result from a modular DM bearing.

Psychosocial Determinants of Total Knee Arthroplasty Outcomes Two Years After Surgery

Objective

To evaluate the association of preoperative psychosocial and demographic factors with total knee arthroplasty (TKA) outcomes and satisfaction in patients with osteoarthritis (OA) of the knee at 24 months after surgery.

Methods

A prospective cohort study of patients undergoing TKA was conducted. Outcome measures included: Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Short Form 36 (SF‐36) scores at baseline and 24 months after surgery, and patient satisfaction with TKA at 24 months. Linear regression models were performed to evaluate the association of preoperative psychosocial determinants (ie, Medical Outcome Study Social Support Scale; Depression, Anxiety, and Stress Scale; Brief COPE inventory, The Life Orientation Test‐Revised; Multidimensional Health Locus of Control; and Arthritis Self‐Efficacy Scale) on outcomes.

Results

We included 178 patients. Increasing WOMAC pain scores at 24 months were associated with increasing age and body mass index (BMI); low tangible social support and low optimism were associated with higher levels of pain (R² = 0.15). A decrease in WOMAC function scores was also associated with older age and higher BMI; low tangible support, increased stress, and low optimism were also associated with worse function (R² = 0.22). When evaluating quality of life, lower SF‐36 physical functioning scores at 24 months were associated with age, high BMI, and comorbidity (R² = 0.34). Lower SF‐36 mental functioning scores were associated with depression and low optimism (R² = 0.38). Having a dysfunctional style of coping was associated with lower satisfaction with surgery after 24 months (adjusted R² = 0.12).

Conclusion

Psychosocial factors, such as tangible support, depression, dysfunctional coping, and optimism, were associated with pain, function, and satisfaction 2 years after TKA. Perioperative programs identifying and addressing psychosocial problems may result in improvements in pain and function after TKA.

One-year Oxford knee scores should be used in preference to 6-month scores when assessing the outcome of total knee arthroplasty

Purpose

The primary aim of this study was to assess whether there was a clinically significant difference in the mean Oxford knee score (OKS) between 6 and 12 months after total knee arthroplasty (TKA). The secondary aim was to identify variables associated with a clinically significant change in the OKS between 6 and 12 months.

Methods

A retrospective cohort study was undertaken using an established arthroplasty database of 1574 primary TKA procedures. Patient demographics, body mass index (BMI), comorbidities, OKS and EuroQoL 5-domain (EQ-5D) score were collected preoperatively and at 6 and 12 months postoperatively. A clinically significant change in the OKS was defined as 5 points or more.

Results

There was a 1.1-point increase in the OKS between 6 and 12 months postoperatively, which was statistically significant (95% confidence (CI) 0.8–1.3, p < 0.0001). There were 381 (24.2%) patients who had a clinically significant improvement in their OKS from 6 to 12 months. After adjusting for confounding, patients with a lower BMI (p = 0.028), without diabetes mellitus (p < 0.001), a better preoperative OKS (p < 0.001) or a worse 6-month OKS (p < 0.001) were more likely to have a clinically significant improvement. A 6-month OKS < 36 points was a reliable predictor of a clinically significant improvement in the 6-month to 12-month OKS (area under the curve 0.73, 95% CI 0.70–0.75, p < 0.001).

Conclusion

Overall, there was no clinically significant change in the OKS from 6 to 12 months; however, a clinically significant improvement was observed in approximately a quarter of patients and was more likely in those scoring less than 36 points at 6 months. Level of evidence: retrospective diagnostic study, level III.

Current state of total knee arthroplasty

Total knee arthroplasty (TKA) is a successful and cost-effective treatment for end-stage degenerative arthritis. The aging of society and an increase in the prevalence of obesity has led to increases in the prevalence of arthritis and the incidence of TKA. Currently, the total number of procedures in Korea per year has reached 90,000. With the rapid growth, we need to know about the current state of TKA. The purpose of this review is to summarize the recent literature regarding TKA. The main indication for TKA is end-stage arthritis with severe pain, reduced function, and no response to conservative management. Metal on the polyethylene-bearing surface and cobalt alloy are used in most TKAs. Despite good clinical outcomes and long-term survival rates after TKA in many papers, 20% of patients are dissatisfied with the outcome of surgery. To improve the patient’s satisfaction, surgeons should understand factors affecting patient’s satisfaction, including patient’s expectations, age, and preoperative mental state. Navigation-assisted surgery and robotic surgery have been introduced in knee arthroplasty to achieve more precise and accurate alignment. There is some evidence to suggest that computer-assisted surgery reduces revision rates. However, clinical efficacy is also controversial, and a long-term follow-up study is required. The common complications of TKA include infection, polyethylene wear, loosening, stiffness, periprosthetic fracture, and thromboembolism. An understanding of the potential complications and pitfalls of TKA is essential for prevention.

There is no clinically important difference in the Oxford knee scores between one and two years after total knee arthroplasty: The one-year score could be used as the benchmark timepoint to assess outcome

BACKGROUND

The aim was to assess the whether there was a clinically important change in the Oxford knee score (OKS) between one and two years after total knee arthroplasty (TKA), and to identify predictors associated with a clinically important change.

METHODS

A retrospective cohort study was undertaken using an established arthroplasty database of 5857 primary TKA. Patient demographics, body mass index, social deprivation, OKS and EuroQoL five-domain (EQ-5D) score were collected preoperatively and at one and two years postoperatively. A clinically important change in the OKS was defined as ≥5 points.

RESULTS

There was a 0.2 point increase in the OKS between one and two years, which was statistically significant (95% confidence interval (CI) 0.1 to 0.4, p < .0001), but not clinically important. A better preoperative OKS (p < .001) and in contrast a worse one year OKS (p < .001) were independently associated with a greater improvement from one to two years. There were 1006 (17.3%) patients that had a clinically important improvement in the OKS between one and two years. Receiver operating characteristic curve analysis showed that a one year OKS of less than 35 was a reliable predictor of a clinically important improvement between one and two years (area under the curve 0.77, 95% CI 0.76 to 0.78, p < .001).

CONCLUSION

There was not a clinically important change in the OKS from one to two years after TKA when assessed as a group. However, individual patients with a one year OKS of less than 35 may demonstrate a clinically important improvement at two years.

LEVEL OF EVIDENCE

Retrospective diagnostic study, Level III.

Changes in actual daily physical activity and patient-reported outcomes up to 2 years after total knee arthroplasty with arthritis

The current study aimed 1) to describe changes in patient-reported outcomes and physical activity measured with an accelerometer preoperatively, 6 months and 2 years postoperatively in older patients undergoing total knee arthroplasty (TKA) for arthritis, and 2) to examine the predictors of the changes in physical activity (PA). This study included 58 patients (mean age 72.6 years, 84.5% women) who completed the Oxford Knee Score (OKS) and the 8-item Short Form Health Survey. Physical activity measured mean steps per day, duration of light physical activity and moderate-to-vigorous physical activity (MVPA) per week. All PA indicators and patient-reported outcomes improved 6 months postoperatively. After 6 months, knee-related pain and function gradually improved, and MVPA increased. The OKS was a sole predictor of improvement in PA during the 2-year study period, suggesting the importance of disease-specific quality of life.

Improved levels of physical activity in patients over 75 years following total knee arthroplasty

PURPOSE

There is insufficient evidence regarding the precise levels of physical activity (PA) in older patients following total knee arthroplasty (TKA). The aims of this study were (1) to describe the changes in the amount and intensity of PA before and after TKA with an accelerometer in older patients, compared with age- and sex-matched healthy participants and (2) to assess the effect of TKA on PA depending on age.

METHODS

Sixty-six primary TKA patients aged 60 years or over (mean age, 73.3 years) wore an accelerometer (Lifecorder EX) for 10 consecutive days and completed the Oxford Knee Score (OKS) before and at 6 months after TKA. PA was evaluated by mean step count and time spent (min) engaged in PA per day. PA intensity was classified as light (1.5-3 metabolic equivalents (METs)), moderate to vigorous (≥3 METs), and total (≥1.5 METs). Sixty-four healthy participants completed a single assessment of PA.

RESULTS

Each of the PA measures and OKS increased significantly after TKA. Compared with healthy controls, light and total PA improved to 100% at 6 months after TKA in patients 75 years or older. By contrast, moderate-to-vigorous PA was 32% of that of the controls and rose to 78% after TKA. PA intensity in patients aged 60-74 years was 31-74% of the controls but did not reach the same level after TKA.

CONCLUSION

TKA in older patients increases the amount of PA, with light and total PA suitable parameters for assessing PA.

Changes in Expectation Fulfillment Following Total Knee Arthroplasty: A 10-Year Follow-Up Study

BACKGROUND

This study aims to investigate how expectation fulfillment changes up to 10 years following total knee arthroplasty (TKA).

METHODS

Preoperative data were collected for 323 patients undergoing TKA (Hospital for Special Surgery Knee Replacement Expectations survey, Oxford Knee Score [OKS], and Short Form [SF]-12). Expectation fulfillment, OKS, SF-12, and patient satisfaction were assessed at 1 year and 9-10 years postoperatively. Relative risk (RR) of dissatisfaction at late follow-up was calculated for each specific expectation question. Linear regression analysis was used to identify factors independently associated with early (1 year) and late (mean 9 years) expectation fulfillment scores.

RESULTS

Mean expectation fulfillment scores declined from early to late follow-up (25.9-23.9, P = .025). Multivariate analysis identified younger age and better 1-year OKS as factors independently associated with long-term expectation fulfillment. Twelve percent of patients reported dissatisfaction at late follow-up. The risk of long-term dissatisfaction was greatest in patients with high preoperative expectations of kneeling (RR 2.2, 95% confidence interval [CI] 0.9-5.5), walking without aids (RR 2.4, 95% CI 0.7-7.6), and improved psychological well-being (RR 3.9, 95% CI 0.9-5.0). Night pain relief, kneeling ability, participating in outside activities, and sports were the most poorly fulfilled expectations at both early and late time points. Fulfillment improved the least from early to late for kneeling ability (17%) and ability to participate in outside activities (17%).

CONCLUSION

Expectation fulfillment following TKA changes with time. Expectations of kneeling ability and the ability to perform outside activities demonstrated persistently low levels of fulfillment. This information can be used to manage the longer term expectations of patients undergoing TKA.

Sex does not clinically influence the functional outcome of total knee arthroplasty but females have a lower rate of satisfaction with pain relief

Background

The aims were to assess whether sex had a clinically significant independent influence on the outcome of total knee arthroplasty (TKA) according to the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, Short Form (SF-) 12 scores and patient satisfaction at 1 year.

Methods

A retrospective cohort of 3510 primary TKA were identified. Patient demographics, comorbidities, WOMAC and SF-12 scores were collected preoperatively and 1 year postoperatively. Patient satisfaction were assessed at 1 year.

Results

There were 1584 males and 1926 females. The preoperative WOMAC and SF-12 scores were significantly (p < 0.001) worse in females but were not greater than the minimal clinically important difference (MCID). When adjustments had been made for confounding differences, females showed a significantly greater improvement in their function (1.5 points, p = 0.03) and total (1.5 points, p = 0.03) WOMAC scores compared to males, but these were not greater than the MCID. When adjustments had been made for confounding differences, females were less likely to be satisfied with their pain relief (p = 0.03) relative to males.

Conclusion

Sex does not clinically influence the knee specific outcome (WOMAC) or overall generic (SF-12) health 1 year after TKA. However, satisfaction with pain relief after TKA was significantly less likely in female patients.

Level of evidence II

Prognostic retrospective cohort study.

Knee arthroplasty system with medialized keel: Seven-year follow-up of a pioneer cohort

BACKGROUND

In this clinical investigation, a new design with a progressive increased keel medialization according to the size was implanted. The cohort of patients was followed up for seven years.

METHODS

From May 2012 to November 2012, we implanted 70 total knee arthroplasties in 69 patients. The mean age of the patients was 76.2 years. We followed up 56 patients for seven years; we evaluated the patients at six and 60 months after surgery by Patient Reported Outcome Measures score. During the seven-year follow-up, all patients were clinically re-evaluated using the Knee Society Score and the Forgotten Joint Score. All patients underwent a preoperative and postoperative radiographic investigation. At the last follow-up the presence of any radiolucency lines was checked using the Knee Society Total Knee Arthroplasty Radiographic Evaluation and Scoring System.

RESULTS

The patients defined the surgical results as excellent in 66% of the cases, very good in 23%, good in five percent. The analysis of the functional data at seven years, performed by administering the Forgotten Joint Score, showed average values of 70.4. The clinical analysis, performed through the Knee Society Score at the same follow-up, showed average values of 90.4. The seven-year radiological analysis revealed the presence of radiolucency lines in 20 implants. The sum of the line widths never exceeded the critical value of nine millimeters, always remaining below four millimeters. Only one patient was revised.

CONCLUSIONS

The results showed an excellent outcome of this design. The medialization of the tibial keel showed good bone fixation and component alignment at seven-year follow-up.

Minimal clinically important differences and substantial clinical benefits for Knee Society Scores

PURPOSE

There is a paucity of literature defining the minimal clinically important difference (MCID) for the Knee Society Scores (KSS) after total knee arthroplasty (TKA), and no data on the substantial clinical benefit (SCB) for KSS have been reported. The purpose of this study was to determine MCID and SCB for the KSS in patients with primary TKA.

METHODS

The median age of patients was 71.6 (range 50-88) years, and 60.3% were females 507 patients with TKA were prospectively enrolled. Patients completed the KSS before surgery and at second postoperative year. The MCID values of the KSS were estimated using anchor-based method, distribution-based method and receiver operating characteristic (ROC) curve analysis with calculation of the area under curve (AUC). SCB was estimated using ROC.

RESULTS

The MCID for KSS-knee score was 7.2 points by the anchor-based method, 7.2 by the distribution-based method, and using a ROC analysis the cutoff point was 8.9 points with an AUC of 0.75. For KSS-function score, the MCID values were 9.7, 6.3, and 10.3 (AUC 0.71), respectively. SCB values were 39.7 points (AUC 0.74) for the KSS-knee score, and 38.6 (AUC 0.76) for the KSS-function score. Logistic regression showed age and Charlson index to negatively affect the changes in KSS.

CONCLUSION

Different methods for MCID calculation lead to different results. With the use of ROC curve analysis, patients with an improvement of at least 9 points for KSS-knee and 10 points for KSS-function scores experience a clinically important change, whereas those who have at least an improvement of 40 points for KSS-knee and 39 points for KSS-function scores experience a substantial clinical benefit. These findings can ensure clinical improvement from the patient's perspective and also aid in interpreting results from clinical studies.

LEVEL OF EVIDENCE

III.

Does total contact of the patella with the femoral trochlea during no thumb test significantly reduce anterior knee pain?

BACKGROUND

Complications such as anterior knee pain (AKP) and crepitus continue to be causes of dissatisfaction after total knee arthroplasty (TKA). This prospective study aimed to study the significance of total patellar contact with the femoral trochlea of the implant, with the no thumb test during trial reduction, and its effect on reducing AKP.

METHODS

Between 2014 and 2016, 445 patellofemoral joints (M:F 126:319, age 45-80 years) and their contact with the trochlea of the femoral component were graded at trial reduction without lateral retinaculum release (Grades I, Ia, II, III based on existing publications). The aim was to restore all patellae to pre-operative thickness. Posterior stabilized implants with a domed patella were used in all cases. The Knee Society Score (KSS) and Visual Analogue Scale (VAS) score were noted at follow up between 12 and 24 months after surgery.

RESULTS

AKP was significantly lower with 100% patellofemoral contact. The KSS and VAS had statistically significant P-values of 0.021 and 0.025 in Grade I and Ia contact, respectively. Better results were achieved where patellar thickness was restored in Grades I and Ia with P-values of 0.041 and 0.046 for VAS change and 0.038 and 0.044 for KSS change, respectively.

CONCLUSION

At follow up, superior results were obtained where there was a complete patellofemoral contact at trial reduction in Grade I and Grade Ia, and when other confounding factors such as patellar thickness and normal rotation of the femoral and tibial components were standardized. To minimize AKP it is imperative to have total patellar contact with the femoral trochlea.

Meaningful changes in the Short Form 12 physical and mental summary scores after total knee arthroplasty

BACKGROUND

The aim of this study was to identify minimal clinically important difference (MCID), minimal important change (MIC) and minimal detectable change (MDC) for the Short Form (SF-) 12 physical and mental component summary (PCS, MCS) scores after total knee arthroplasty (TKA) using an anchor based methodology.

METHODS

During a 10-year period, 2589 TKA were performed. SF-12 PCS and MCS scores were recorded preoperatively and at one year postoperatively. At one year, patients were asked "How much did the knee replacement surgery improve the quality of your life?" Their response was recorded as: a great improvement, moderate improvement, little improvement, no improvement at all, or the quality of my life is worse. Patients recording a little (n = 211) and no (n = 115) were used to calculate the MCID and the MIC. The MDC90 was calculated using distribution based methods for the whole cohort.

RESULTS

The MCID was 1.8 (p = 0.04) for the PCS and 1.5 (p = 0.33) for the MCS score. The MIC was 2.7 (p = 0.04) for the PCS and -1.4 (p = 0.17) for the MCS score. The MDC90 was 8.9 for the PCS and 13.8 for the MCS score.

CONCLUSION

The MCID for the PCS can be used to compare the outcomes between groups, and the MIC can be used to ensure that a clinical difference has been observed for a cohort of patients. The values for the MDC90 can be used to assess whether or not an individual patient has experienced a change.

The Evaluation of Single-Sided Total Knee Arthroplasty Versus Simultaneous Bilateral Total Knee Arthroplasty Improvements and Postoperative Progression Based on Patient-Based Outcome Scoring: A Rural Retrospective Clinical Orthopaedic Study

INTRODUCTION

Both graduated single-sided total knee arthroplasty (SSTKA) and simultaneous bilateral total knee arthroplasty (SBTKA) are viable options for bilateral knee arthritis, and deciding which option to pursue is still debated. We aim to compare the two modalities using the patient-based oxford knee score and Visual analog pain scores in micropolitan settings.

METHODS

Oxford knee score and Visual analog pain scores were administered preoperatively and postoperatively 1, 6, and 12 months to 115 patients who underwent total knee arthroplasty. The 115 cohort was divided into two groups, those who underwent SSTKA and those who received SBTKA.

RESULTS

Cross-group analysis showed a significant difference with oxford scores at the 1-month postoperative interval (P = 0.026). The within-group analysis of the delta oxford knee scores displayed postoperative improvement at the 0.05 level of significance at 1, 6, and 12 months.

DISCUSSION

This study indicates that the patient-based outcome measures for the SBTKA group lagged behind the SSTKA group. The overall improvement a year out from surgery is comparable, and both groups had significant improvement in function. The SBTKA patient group had markedly lower functional outcome measures based on oxford scores at 1 month post-op compared with the SSTKA group; this may help in decision-making and patient selection.

Survival and functional outcome of revision total knee arthroplasty with a total stabilizer knee system: minimum 5 years of follow-up

INTRODUCTION

Revision knee arthroplasty surgery can range from patella resurfacing or polyethylene exchange, to staged revision and revision to a more constrained implant. Subsequently, the ability to elicit outcomes becomes difficult to obtain and hence information on functional outcome and survivorship for all modes of failure with a single revision system is valuable.

METHODS

We retrospectively assessed 100 consecutive revision knee replacements that were converted from a primary knee replacement to a Triathlon total stabilizer (TS) knee system (Stryker Orthopaedics, Mahwah, NJ). Inclusion criteria included failure of a primary knee replacement of any cause converted to a Stryker TS knee system. Midterm outcome of at least 5 years was required. Implants survivorship, Oxford Knee Score (OKS), Forgotten Joint Score (FJS-12), Short Form (SF-) 12, reported patient satisfaction and radiographic analysis were recorded.

RESULTS

The all-cause survival rate at 5 years was 89.0% [95% confidence interval (CI) 87.3 to 90.7]. The all-cause survival rate was generally static after the first 4 years. The mean OKS was 27 (SD 11.9, range 0 to 46), FJS was 32.3 (SD 30.4, range 0 to 100), SF-12 physical component summary was 40.6 (SD 17.6, range 23.9 to 67.1), and mental component summary was 48.3 (SD 15.5, range 23.9 to 69.1). Reported patient satisfaction in patients who were not re-revised was 82%.

CONCLUSION

The midterm survivorship of cemented Stryker Triathlon TS knee revision for all-cause mode of failure is good to excellent; however, future follow-up is required to ensure this survivorship is observed into the long term. Despite limited functional outcome, overall patient satisfaction rates are high.

What is the Minimum Clinically Important Difference for the WOMAC Index After TKA?

BACKGROUND

The WOMAC score is a validated outcome measure for use in patients undergoing TKA. Defining meaningful changes in the WOMAC score is important for sample-size calculations in clinical research and for interpreting published studies. However, inconsistencies among published studies regarding key definitions for changes in the WOMAC score after TKA potentially could result in incorrectly powered studies and the misinterpretation of clinical research results.

QUESTIONS/PURPOSES

(1) To identify the minimum clinically important difference (MCID) for the total WOMAC score and its components 1 year after TKA using an anchor-based methodology. (2) To define the minimum important change (MIC) and the minimum detectable change with 95% confidence (MDC95) for the total WOMAC score and its components 1 year after TKA.

METHODS

Between 2003 and 2013, 3641 patients underwent primary TKA at one center. Of those, 460 patients (13%) were excluded from this retrospective study for prespecified reasons (mainly secondary OA and bilateral surgery), and 592 patients (16%) were either lost to followup or could not be included because of incomplete questionnaires. WOMAC scores were recorded preoperatively and at 1 year postoperatively. Patient demographics and preoperative Short Form-12 and WOMAC scores were no different for the 16% of patients who were lost to followup or failed to complete 1-year questionnaires and the study cohort (n = 2589). At 1 year, patients were asked "How much did the knee replacement surgery improve the quality of your life?" Their responses were recorded as: a great improvement, moderate improvement, little improvement, no improvement at all, or the quality of my life is worse. The MCID was defined as the difference in the mean change in the WOMAC score between patients with no improvement compared with those with little improvement according to the anchor question. The MIC was defined as the change in the WOMAC score relative to the baseline score for patients who reported a little improvement in their quality of life. The MDC is the smallest change for an individual who is likely to be beyond the measurement error of the scoring tool and represents true change rather than variability in the scoring measure; we report it with 95% confidence bounds defining real change rather than variability in the scoring measure (MDC95). We calculated this with distribution-based methods for the whole cohort. Patients recording a little improvement (n = 211) and no improvement (n = 115) were used as anchor responses to calculate the MCID (using regression analysis to adjust for potential confounding variables such as age, gender, BMI and preoperative Short Form-12 or WOMAC scores) and the MIC (using receiver operative characteristics curves).

RESULTS

After adjusting for confounding variables such as age, gender, BMI as well as preoperative Short Form-12 and WOMAC scores, the MCID was 11 for pain, 9 for function, 8 for stiffness and 10 for the total WOMAC score. The MIC was 21 for pain, 16 for function, 13 for stiffness and 17 for the total WOMAC score. The MDC95 was 23 for pain, 11 for function, 27 for stiffness and 12 for the total WOMAC score.

CONCLUSIONS

The MCID and MIC for the WOMAC score represent the smallest meaningful effect sizes when comparing the outcome of two groups (difference in mean change between the groups) or when assessing a cohort (a change in score for the group) after TKA, respectively, helping the reader to distinguish between a clinically important effect size and a mere statistical difference. We determined that the error in measurement (based on the MDC95) for the function component and total WOMAC scores were less than the MIC, which suggests changes beyond the MIC are clinically real and not due to uncertainty in the score. These parameters are essential to interpret TKA outcomes research and to ensure clinical research studies are amply powered to detect meaningful differences. Future studies using the WOMAC score to assess TKA outcomes should report not only the statistical significance (a p value) but also the clinical importance using the reported MCID and MIC values.

LEVEL OF EVIDENCE

Level III, diagnostic study.

The prognostic value of pain catastrophizing in health-related quality of life judgments after Total knee arthroplasty

Background

Total knee arthroplasty (TKA) is a highly effective procedure that yields reductions in pain and disability associated with end stage osteoarthritis (OA) of the knee. Quality of life instruments are frequently used to gauge the outcomes of total knee arthroplasty (TKA). However, research suggests that post-TKA reductions in symptom severity may not be the sole predictors of quality of life post-TKA. The primary objective of the present study was to examine the prognostic value of catastrophic thinking in health-related quality of life (HRQoL) judgments in patients with severe OA after TKA.

Methods

In this study we used a prospective cohort design to examine the value of pain catastrophizing in predicting HRQoL 1 year after TKA. Participants with advanced OA of the knee who were scheduled for TKA were recruited at one of three hospitals in Canada. The study sample consisted of 116 individuals (71 women, 45 men) who completed study questionnaires at their pre-surgical evaluation and 1 year after surgery. Hierarchical regression analysis was used to assess the unique contribution of pre-surgical pain catastrophizing to the prediction of post-surgical HRQoL judgments.

Results

The results of the hierarchical regression equation revealed that the overall model was significant, F (9,106) = 8.3, p < 001, and accounted for 36.4% of the variance in the prediction of post-surgical physical component score of HRQoL. Pain catastrophizing was entered in the last step of the equation and contributed significant unique variance (β = −.35, p < .001) to the prediction of post-surgical physical component score of HRQoL above and beyond the variance accounted for by demographic variables, co-morbid health conditions, baseline HRQoL, and post-surgical reductions in pain, joint stiffness and physical disability.

Conclusions

The current findings highlight the importance of pre-surgical catastrophic cognitions in influencing HRQoL judgments after TKA. The findings suggest that psychosocial interventions designed to reduce pain catastrophizing before TKA might contribute to better quality of life outcomes following surgery.

The rate and predictors of patient satisfaction after total knee arthroplasty are influenced by the focus of the question: a standard satisfaction question is required

Aims

The primary aim of this study was to assess the rate of patient satisfaction one year after total knee arthroplasty (TKA) according to the focus of the question asked. The secondary aims were to identify independent predictors of patient satisfaction according to the focus of the question.

Patients and Methods

A retrospective cohort of 2521 patients undergoing a primary unilateral TKA were identified from an established regional arthroplasty database. Patient demographics, comorbidities, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and 12-Item Short-Form Health Survey (SF-12) scores were collected preoperatively and one year postoperatively. Patient satisfaction was assessed using four questions, which focused on overall outcome, activity, work, and pain. Logistic regression analysis was used to identify independent preoperative predictors of increased stiffness when adjusting for confounding variables.

Results

Using patient satisfaction with the overall outcome (n = 2265, 89.8%) as the standard, there was no difference in the rate of satisfaction for pain relief (n = 2277, odds ratio (OR) 0.95, 95% confident intervals (CI) 0.79 to 1.14, p = 0.60), but patients were more likely to be dissatisfied with activities (79.3%, n = 2000/2521, OR 2.22, 95% CI 1.96 to 2.70, p < 0.001) and work (85.8%, n = 2163/2521, OR 1.47, 95% CI 1.23 to 1.75, p < 0.001). Logistic regression analysis identified different predictors of satisfaction for each of the focused satisfaction questions. Overall satisfaction was influenced by diabetes (p = 0.03), depression (p = 0.004), back pain (p < 0.001), and SF-12 physical (p = 0.008) and mental (p = 0.01) components. Satisfaction with activities was influenced by depression (p = 0.001), back pain (p < 0.001), WOMAC stiffness score (p = 0.03), and SF-12 physical (p < 0.001) and mental (p < 0.001) components. Satisfaction with work was influenced by depression (p = 0.007), back pain (p < 0.001), WOMAC function (p = 0.04) and stiffness (p = 0.05) scores, and SF-12 physical (p < 0.001) and mental (p < 0.001) components. Satisfaction with pain relief was influenced by diabetes (p < 0.001), back pain (p < 0.001), and SF-12 mental component (p = 0.04).

Conclusion

The focus of the satisfaction question significantly influences the rate and the predictors of patient satisfaction after TKA. Cite this article: Bone Joint J 2018;100-B:740-8.

Three groups of dissatisfied patients exist after total knee arthroplasty: early, persistent, and late

AIMS

The primary aim of this study was to assess whether patient satisfaction one year after total knee arthroplasty (TKA) changed with longer follow-up. The secondary aims were to identify predictors of satisfaction at one year, persistence of patient dissatisfaction, and late onset dissatisfaction in patients that were originally satisfied at one year.

PATIENTS AND METHODS

A retrospective cohort consisting of 1369 patients undergoing a primary TKA for osteoarthritis that had not undergone revision were identified from an established arthroplasty database. Patient demographics, comorbidities, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores, and Short Form 12 (SF-12) questionnaire scores were collected preoperatively, and one and five years postoperatively. In addition, patient satisfaction was assessed at one and five years postoperatively. Logistic regression analysis was used to identify independent predictors of satisfaction at one and five years.

RESULTS

The overall rate of satisfaction did not change from one (91.7%, n = 1255) to five (90.1%, n = 1234) years (p = 0.16). Approximately half (n = 53/114) of the patients who were dissatisfied at one year became satisfied with their TKA at five years, whereas 6% (n = 74/1255) of those who were satisfied at one year became dissatisfied at five years. At one year, patients with lung disease (p = 0.04), with depression (p = 0.001), with back pain (p < 0.001), undergoing unilateral TKA (p = 0.001), or with a worse preoperative WOMAC pain score (p = 0.04) were more likely to be dissatisfied. Patients with gastric ulceration (p = 0.04) and a worse WOMAC stiffness score (p = 0.047) were at increased risk of persistent dissatisfaction at five years. In contrast, a worse WOMAC pain score (p = 0.01) at one year was a predictor of dissatisfaction in previously satisfied patients at five years.

CONCLUSION

Three groups of dissatisfied patients exist after TKA: 'early' dissatisfaction at one year, 'persistent' dissatisfaction with longer follow-up, and 'late' dissatisfaction developing in previously satisfied patients at one year. All three groups have different independent predictors of satisfaction, and potentially addressing risk factors specific to these groups may improve patient outcome and their satisfaction. Cite this article: Bone Joint J 2018;100-B:161-9.

Birmingham Hip Resurfacing vs Total Hip Arthroplasty: A Matched-Pair Comparison of Clinical Outcomes

BACKGROUND

Birmingham hip resurfacing (BHR) has proven to be a good alternative for younger patients with osteoarthritis. Some have asserted that BHR may yield outcomes which are superior to total hip arthroplasty (THA), and that some studies which failed to show a difference were plagued by ceiling effects and lack of sensitivity of outcome measures. The purpose of this study is to compare outcomes of BHR and THA using the "Forgotten Joint" Score-12 (FJS), a more sensitive score with lesser vulnerability to the ceiling effect.

METHODS

Patients who underwent BHR were matched to patients who underwent posterior THA by computing a propensity score using 5 covariates: age, body mass index, gender, worker's compensation claims, and previous hip surgery. Surgical outcomes were assessed using 6 patient-reported outcome measures, including the FJS, the visual analog scale for pain, and patient satisfaction.

RESULTS

There were 42 patients in the BHR group and 18 patients in the THA group. The FJS was 78.0 for the BHR group and 76.0 for the THA group. The Veterans RAND 12-Item Health Survey Mental Component Summary and Short Form 12 Mental Component Summary were significantly higher in the BHR group. No differences were seen between all other patient-reported outcomes.

CONCLUSION

BHR offers excellent results in young patients that are comparable to THA. As no clinical difference could be shown between BHR and THA, even with the use of the FJS, the choice between BHR and THA should not be based solely on any expectation that either yields superior clinical outcomes compared to the other at short-term follow-up.

Validation of the Chinese (Mandarin) Version of the Oxford Knee Score in Patients with Knee Osteoarthritis

BACKGROUND

With the increasing number of patients with knee osteoarthritis undergoing TKAs in China, there is a clear need for a valid, short, joint-specific patient-reported outcome measure such as the Oxford Knee Score (OKS).

QUESTIONS/PURPOSES

To test the translated and cross-culturally adapted Chinese (Mandarin) version of the Oxford Knee Score (OKS-CV) and its (1) reliability, (2) construct validity, (3) dimensionality, and (4) responsiveness.

METHODS

Three native Chinese bilingual translators (a professional English translator, an experienced orthopaedic surgeon, an advanced-practice nursing specialist) translated the English-language OKS into Mandarin Chinese. A consensus panel created a synthesis of those efforts, which then was back-translated by two bilingual nonmedical, professional English-language translators. The OKS-CV was developed according to the guidelines of copyright holders. Between March 2013 and March 2015, 253 patients underwent TKAs. Among them, 114 Mandarin-speaking patients with knee osteoarthritis underwent primary unilateral TKA (age, 67 ± 7 years; range, 55-84 years; female, 80%; preoperatively 54% had moderate to severe knee osteoarthritis), completed the preoperative questionnaires, and were followed up, with a mean postoperative followup of 2.7 years (SD, 0.5 years). Eligibility criteria were (1) patients with knee osteoarthritis who were scheduled to have a primary unilateral TKA, (2) patients who were fluent in Mandarin, and (3) consent to participate. The exclusion criteria were: (1) lack of understanding of Mandarin, and (2) inability to comprehend the questionnaires owing to cognitive impairment. To evaluate test-retest reliability, another group of 35 Mandarin-speaking outpatients with knee osteoarthritis (age, 61 ± 10 years; range, 44-84 years; female, 77%) was recruited to complete the OKS-CV twice at a 1-week interval. Reliability was tested using Cronbach's alpha and intraclass correlation coefficient (ICC). Construct validity was evaluated using Spearman's rank correlation coefficient to quantify the correlations between the OKS-CV and the WOMAC, Short Form-8 Health Survey (SF-8^TM), and EuroQol Group 5-Dimension Self-Report Questionnaire (EQ-5D). Exploratory factor analysis was performed to clarify dimensionality. The eigenvalue indicates the importance of each factor obtained from factor analysis. Responsiveness was determined by standardized response mean (SRM) and effect size (ES) from preoperative and postoperative scores of the OKS-CV. Floor and ceiling effects also were analyzed.

RESULTS

The internal consistency (Cronbach's alpha = 0.89) and test-retest reliability (ICC = 0.93; 95% CI, 0.87-0.97) proved good. Convergent construct validity was supported by moderate to strong correlations between the OKS-CV and the WOMAC (r = -0.80, p < 0.001), the SF-8^TM physical component summary (r = 0.65, p < 0.001), and the EQ-5D usual activities (r = -0.41, p < 0.001) and mobility (r = -0.35, p < 0.001). There also were correlations between the OKS-CV and the SF-8^TM mental component summary (r = 0.58, p < 0.001) and the EQ-5D anxiety/depression (r = -0.35, p < 0.001). The factor analysis yielded three factors with eigenvalues greater than 1. Responsiveness was excellent (SRM = 1.52; ES = 1.52). No floor or ceiling effect was observed.

CONCLUSIONS

The OKS-CV showed good acceptability and psychometric properties for the intended population. Future studies are needed to evaluate the mental state of patients with knee osteoarthritis.

CLINICAL RELEVANCE

The OKS-CV appears to be a reliable, valid, and responsive instrument for Chinese patients with knee osteoarthritis. Based on these results we believe the OKS-CV can be used as a valuable tool for the assessment of patient-reported outcomes in Chinese patients with knee osteoarthritis before and after TKA.

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.

Advances in Computer-Aided Technology for Total Knee Arthroplasty

Technology such as computer-assisted navigation systems, robotic-assisted systems, and patient-specific instrumentation has been increasingly explored during the past decade in an effort to optimize component alignment and improve clinical outcomes. Computer-assisted navigation accurately restores mechanical-axis alignment, but clinical outcome data are inconsistent. Computer-assisted navigation gap balancing has shown early promise in establishing mechanical-axis alignment with improved functional outcomes. Robotic-assisted systems more accurately restore component alignment when compared with computer-assisted navigation, but clinical outcomes have yet to be determined. Patient-specific instrumentation does not consistently improve alignment, accuracy, or patient outcomes. Studies demonstrating implant survivorship, cost-efficiency, and improved clinical outcomes and patient satisfaction are needed. [Orthopedics. 2017; 40(6):338-352.].

Single-stage total knee arthroplasty and osteotomy as treatment of secondary osteoarthritis with severe coronal deviation of joint surface due to extra-articular deformity

PURPOSE

Severe extra-articular deformities can be treated with single-stage total knee replacement (TKA) and osteotomy. Aim of this study was to examine the patient-reported outcome measures (PROMs) and the complications after single-stage TKA and osteotomy. We hypothesized patients achieve good outcome after single-stage TKA and osteotomy, which is comparable to outcome after primary TKA without deformity.

METHODS

Twenty-one patients with severe extra-articular deformity who underwent single-stage TKA and deformity-correcting osteotomy were reviewed and invited to fill in PROMs including the Oxford Knee Score, the Short Form-12, a Visual Analogue Scale for pain, and questions about satisfaction and quality of life.

RESULTS

The mean follow-up period was 64 months. Ten patients were treated with TKA and supracondylar femoral osteotomy. Although PROMs showed good results (mean quality of life score was 85 out of 100), two patients had a revision of the osteotomy due to non-union. Eleven patients were treated with TKA and high tibial osteotomy. Patients were satisfied with the results (mean quality of life score was 81 out of 100). Two patients developed infection requiring debridement, resulting in one arthrodesis and one gastrocnemius transfer for wound closure.

CONCLUSION

In general, patients were satisfied with the postoperative result. Outcome was comparable to patients after primary TKA in the literature. However, serious complications need to be taken into account.

LEVEL OF EVIDENCE

III.

Postoperative Anteroposterior Laxity Influences Subjective Outcome After Total Knee Arthroplasty

BACKGROUND

We hypothesized that postoperative anteroposterior (AP) stability of the knee correlates with patient-reported clinical outcome and knee function after total knee arthroplasty (TKA).

METHODS

This study enrolled 110 knees in 81 patients after TKA. AP laxity was measured with a KS Measure Arthrometer at 30°, 60°, and 90° flexion, which was confirmed with a goniometer. We assessed knee pain and function by using the Knee Society Function Score (KSS) and Knee Injury and Osteoarthritis Outcome Score (KOOS). Correlations among AP translation values and KOOS subscale scores (pain symptom, activities of daily living, and knee-related quality of life), KSS, and range of motion (ROM) were analyzed.

RESULTS

The mean follow-up period for the assessment of the KOOS was 4.4 ± 2.2 years (range, 1.1-11.5 years). Twenty-five knees had posterior-stabilized fixed-bearing TKA, and 85 knees had posterior-stabilized mobile-bearing TKA. The mean KSS functional score and mean ROM were 96.3 ± 5.7 (range, 75-100) and 121.6° ± 14.4° (range, 90°-145°), respectively. The mean AP laxity was 4.5 ± 2.2 mm, 3.6 ± 1.9 mm, and 3.0 ± 1.9 mm at 30°, 60°, and 90° knee flexion, respectively. A significant inverse association was observed between AP laxity at 60° knee flexion and KOOS pain (P = .02^∗, R² = 0.05), but no significant association was found between AP laxity and other KOOS subscale score, KSS, and ROM.

CONCLUSION

We found that the AP laxity at 60° knee flexion in this study significantly correlated with patient-reported pain. The observed AP laxity can be considered as a register of normal AP translations after arthroplasty.

Customized versus Patient-Sized Cruciate-Retaining Total Knee Arthroplasty: An In Vivo Kinematics Study Using Mobile Fluoroscopy

BACKGROUND

Historically, knee arthroplasties have been designed using average patient anatomy. Recent advances in imaging and manufacturing have facilitated the development of customized prostheses designed to fit the unique shape of individual patients. The purpose of this study is to determine if improving implant design through customized total knee arthroplasty (TKA) improves kinematic function.

METHODS

Using state-of-the-art mobile fluoroscopy, tibiofemoral kinematics were analyzed for 24 subjects with a customized individually made (CIM), cruciate-retaining TKA, and 14 subjects having an asymmetric condylar cruciate-retaining TKA. Subjects performed a weight-bearing deep knee bend and a rise from a seated position. Each patient was evaluated for weight-bearing range of motion, femorotibial translation, femorotibial axial rotation, and condylar liftoff occurrence.

RESULTS

Subjects having a CIM TKA experienced greater weight-bearing knee flexion compared with the traditional posterior cruciate-retaining (PCR) TKA design. During flexion, the CIM TKA subjects consistently exhibited more posterior femoral rollback than the traditional PCR TKA subjects. The CIM TKA was found to have statistically greater axial rotation compared with the traditional PCR TKA (P = .05). Of note, only the CIM TKA patients experienced femoral internal rotation at full extension, as exhibited in a normal knee. Compared with the traditional PCR TKA, the CIM TKAs demonstrated minimal occurrences of paradoxical sliding and reverse rotation during flexion and extension. The CIM TKA subjects showed minimal liftoff and hence better stability in earlyflexion to midflexion compared with the traditional PCR subjects.

CONCLUSION

The CIM TKA demonstrated kinematics more similar to a normal knee. Therefore, using customized implant technology through CIM TKA designs affords benefits including more normal motion compared with a traditional PCR TKA.

Clinical and Radiographic Results of Attune and PFC Sigma Knee Designs at 2-Year Follow-Up: A Prospective Matched-Pair Analysis

BACKGROUND

Anterior knee pain (AKP) and/or crepitation are important causes of dissatisfaction after total knee arthroplasty (TKA). Aim of this prospective, matched-pair study was to compare 2 different designs of patellofemoral (ie, trochlear groove) TKA. The Attune knee has an anatomic trochlear groove with a medialized dome patellar component vs the PFC Sigma with a single radius trochlear groove with a domed shaped patella.

METHODS

Between January 2010 and December 2014, 100 consecutive Attune TKAs were matched to 100 PFC Sigma TKAs based on age, gender, side, and body mass index. All surgeries were performed via medial parapatellar approach and used cemented, posterior-stabilized implants with patellar resurfacing. Clinical evaluations were assessed using Knee Society Scores (KSS) and a patient-administered questionnaire at 2-year follow-up (range, 1.5-3 years).

RESULTS

Based on the KSS clinical rating system, excellent clinical results were achieved in 89.4% and 90.7% of Attune and PFC Sigma TKAs, respectively. There were no significant differences in the KS pain or function scores. The overall incidence of AKP was significantly lower with the Attune knee compared to that of the PFC Sigma (12.5% vs 25.8%; P = .02). The incidence of hearing or feeling noise was also less with the Attune knee (17.7% vs 30.9%; P = .02). The incidence of painful crepitation was low in both groups (1.0% vs 4.1%) with no significant difference between groups (P = .37). Both groups had similar high satisfaction scores of 8.6 and 8.4 for the Attune and PFC groups, respectively (P = .09).

CONCLUSION

At 2-year follow-up, there were no differences between the PFC Sigma and Attune knees in KSS or satisfaction. However, the Attune group had a lesser incidence of AKP and crepitation. Further studies should focus on AKP and noise in cruciate-retaining knees.

A patient's perception of their hospital stay influences the functional outcome and satisfaction of total knee arthroplasty

INTRODUCTION

To assess whether patient satisfaction with their hospital stay influences the early outcome of total knee arthroplasty (TKA).

METHODS

During a 5-year period patients undergoing primary TKA at the study centre had prospective outcome data recorded (n = 2264). The Oxford knee score (OKS) and the short form (SF)-12 were recorded pre-operatively and 1 year post-operatively when satisfaction with their TKA was also assessed. Patient satisfaction with their hospital stay was also evaluated and their reasons for it were qualitatively documented.

RESULTS

Decreasing level of satisfaction with their hospital stay was associated with a significantly worse post-operative OKS (p < 0.001) and SF-12 score (p < 0.001). Multivariable regression analysis confirmed that the patient's perceived level of satisfaction with their hospital stay was an independent predictor of change in the OKS (p < 0.001) and SF-12 score (p < 0.006) after adjusting for confounding variables. Patient satisfaction with their TKA was significantly influenced by their hospital experience, decreasing from 96% in those with an excellent experience to 42% in those with a poor experience. Food, staff/care, and the hospital environment were the most frequent reasons of why patients rated their hospital experience as fair or poor.

CONCLUSION

A patient's perception of their inpatient hospital experience after surgery is an important modifiable predictor of early functional outcome and satisfaction with TKA.

Improvement in health-related quality of life after unilateral total knee arthroplasty in patients with bilateral knee osteoarthritis

PURPOSE

To review the outcome of unilateral total knee arthroplasty (TKA) in patients with bilateral knee osteoarthritis (OA) to determine whether unilateral TKA can achieve good health-related quality of life (HRQoL).

METHODS

Records of 68 women and 25 men with severe bilateral knee OA who underwent unilateral TKA on the more symptomatic knee by a single surgeon and did not return for the second TKA within 2 years were reviewed. Outcome at 6 months and 2 years was assessed using the mental and physical component summary (MCS and PCS) of the Short-Form 36 (SF-36) for HRQoL as well as the Oxford Knee Score (OKS) and Knee Society Score (KSS) for knee-specific outcome.

RESULTS

The SF-36, OKS, and KSS improved significantly after unilateral TKA. Respectively for MCS and PCS of SF-36, OKS, and KSS knee and function scores, 65%, 89%, 98%, 98%, and 98% of patients reported absolute improvement at 2 years. Respectively for PCS, OKS, and KSS function score that a minimal clinically important difference (MCID) was established, 77%, 96%, and 80% of patients achieved MCID at 2 years.

CONCLUSION

Unilateral TKA achieves good outcome in HRQoL at 2 years in patients with bilateral knee OA.

Concomitant low back pain impairs outcomes after primary total knee arthroplasty in patients over 65 years: a prospective, matched cohort study

INTRODUCTION

Knee osteoarthritis and low back pain (LBP) are two conditions with relatively high prevalence in patients over 65 years. The objective was to determine the effect of symptomatic LBP on the patient-reported outcome after primary TKA.

MATERIAL AND METHOD

A cohort of 48 patients with concomitant LBP was prospectively matched 1:2 with patients without LBP for gender, age, body mass index and preoperative knee function. LBP severity was measured with the Oswestry Disability Index (ODI). Patient-reported outcomes were assessed with reduced Short-Form (SF12), Western Ontario and McMaster Universities score (WOMAC), and visual analogue scale (VAS) for satisfaction. Functional outcome was assessed with the Knee Society Scores (KSS).

RESULTS

The mean postoperative follow-up was 3.2 years. At last follow-up, LBP cohort had significantly worse SF12, WOMAC, KSS and VAS scores than those patients without LBP. Preoperative ODI score was significantly correlated with outcomes.

CONCLUSION

Worse functional and patient-reported outcomes were obtained in patients over 65 years with concomitant LBP, and this was related to the intensity of preoperative LBP. Despite successful outcome in the knee, the LBP usually remains after TKA and this may impair satisfaction and patient-reported outcomes. These patients should be properly informed about their potential outcomes.