Appropriate questionnaires for knee arthroplasty. Results of a survey of 3600 patients from The Swedish Knee Arthroplasty Registry

Analysis of robot-specific operative time and surgical team anxiety level and its effect on alignment during robot-assisted TKA

Adapting to robotic-assisted (RA) total knee arthroplasty (TKA) is hindered by the surgeon's fear of extra time. The main purpose of this study was to determine the robot's operative time, and the secondary goals were to assess the surgical team's anxiety, implant location and size, and limb alignment. From February to April 2022, 40 participants participated in prospective research. The study included primary Cuvis joint active RA-TKA patients for end-stage arthritis, but conversion of unicompartmental knee arthroplasty to TKA, and patients with prior knee surgery were excluded. The active RA-TKA surgical time included surgeon-dependent and surgeon-independent/active robot time. The surgeon's anxiety was measured using the state-trait anxiety inventory (STAI). The implant size/position and limb alignment were checked by post-operative weight-bearing lateral, anteroposterior, and full-length scanograms. Operative time specifically related to active RA-TKA was higher in the first 10 cases as against 10-20, 20-30 and 30-40 cases which was observed to lower from cohort 2. A similar trend was observed for the surgical team's anxiety levels which seem to lower from cohort 2 (case 10-20). Cumulative experience of active RA-TKA showed no effect on the precision of implant alignment/ size, limb alignment and complications. The study showed progressive improvement in the surgical anxiety scores and reduction in operating time indicating the proficiency gained by the surgical team. Further no learning curve was involved in achieving the implant positioning and sizing, limb alignment with the absence of complications.

Fifteen-year prospective longitudinal cohort study of outcomes following single radius total knee arthroplasty

Aims

This prospective study reports longitudinal, within-patient, patient-reported outcome measures (PROMs) over a 15-year period following cemented single radius total knee arthroplasty (TKA). Secondary aims included reporting PROMs trajectory, 15-year implant survival, and patient attrition from follow-up.

Methods

From 2006 to 2007, 462 consecutive cemented cruciate-retaining Triathlon TKAs were implanted in 426 patients (mean age 69 years (21 to 89); 290 (62.7%) female). PROMs (12-item Short Form Survey (SF-12), Oxford Knee Score (OKS), and satisfaction) were assessed preoperatively and at one, five, ten, and 15 years. Kaplan-Meier survival and univariate analysis were performed.

Results

At 15 years, 28 patients were lost to follow-up (6.1%) and 221 patients (51.9%) had died, with the mean age of the remaining cohort reducing by four years. PROMs response rates among surviving patients were: one-year 63%; five-year 72%; ten-year 94%; and 15-year 59%. OKS and SF-12 scores changed significantly over 15 years (p < 0.001). The mean improvement in OKS was 18.8 (95% confidence (CI) 16.7 to 19.0) at one year. OKS peaked at five years (median 43 years) declining thereafter (p < 0.001), though at 15 years it remained 17.5 better than preoperatively. Age and sex did not alter this trajectory. A quarter of patients experienced a clinically significant decline (≥ 7) in OKS from five to ten years and from ten to 15 years. The SF-12 physical component score displayed a similar trajectory, peaking at one year (p < 0.001). Patient satisfaction was 88% at one, five, and ten years, and 94% at 15 years. In all, 15-year Kaplan-Meier survival was 97.6% (95% CI 96.0% to 99.2%) for any revision, and 98.9% (95% CI 97.9% to 99.9%) for aseptic revision.

Conclusion

Improvements in PROMs were significant and maintained following single radius TKA, with OKS peaking at five years, and generic physical health peaking at one year. Patient satisfaction remained high at 15 years, at which point 2.4% had been revised.

Patella non-resurfacing in primary total knee arthroplasty provides good functional results-a retrospective review of nine thousand three hundred forty six knees

PURPOSE

Patellar resurfacing has long been a contentious subject in TKA with no consensus and the literature yielding disparate results. The aim of this study was to evaluate the long-term functional outcomes and complications of patients undergoing primary TKA without patellar resurfacing (non-resurfacing).

METHODS

This study retrospectively analysed 9346 patients who underwent primary manual jig-based TKA without patellar resurfacing at a single high-volume arthroplasty centre between 2010 and 2018. Patients with a minimum three year follow-up irrespective of disease etiology and implant manufacturer were included in the study. Primary outcome was measured using Oxford knee score and patellofemoral Feller score. Secondary outcomes included determining the incidence of patellofemoral complications and re-operation rates following TKA.

RESULTS

A total of 8695 knees were eligible for final evaluation having a mean follow-up of 6.6 years. Mean age of the patients was 62.6 (SD-7.5) years with female predominance of (N-6619, 70.8%). The majority of the patients had primary OA (N-8792, 94.1%) with varus deformity (N-8642, 92.46%). Depuy was the most used manufacturer (n = 2592, 26.4%) with the posterior stabilised (N-4127, 44.2%) design being the most predominant. The mean Feller score of the study population was 24.5 (SD = 3) with a majority of patients having good to excellent outcomes (86.95%, N-8424) and mean Oxford knee score was 36.9 (SD-6.9) with a majority of the patients having an OKS greater than 30 (87.1%, N-8133) with anterior knee pain (AKP) reported in only 4.8% patients (N-418). Most common complications included patellar clunk (N-56, 0.7%), traumatic patellar fractures (N-62, 0.8%), quadriceps tendon tear (N-54, 0.7%) and patellar dislocation (N-4, 0.05%) CONCLUSION: Patellar non-resurfacing has no detrimental impact on functional outcomes and incidence of AKP. We conclude that it is a safe, cost-effective and satisfactory approach in primary TKA with no significant complications.

The mid-term survival of cemented, uncemented, and hybrid fixation of the ACS mobile bearing total knee arthroplasty

Background

Till today, Cemented Fixation in Total Knee Arthroplasty (TKA) is significantly more used than Hybrid or Uncemented Fixation. The purpose of this study was to compare Cemented, Uncemented and Hybrid Fixation of the ACS Mobile Bearing TKA at Mid-term follow-up.

Methods

This study was an extended data report of our prospective single-center, single-blinded randomized controlled clinical trial comprising 105 patients. The primary outcome was survival at five years of follow-up calculated by Kaplan-Meier and Log-rank test. The secondary outcome was function based on patient-reported outcome measures (PROMs).

Results

Eighty-three patients were included, of which 25 belonged into group A (Cemented), 28 in group B (Uncemented), and 30 in group C (Hybrid). Mean follow-up was 5.8 ± 0.7 (range 5-7) years. The 5-year survival rates were 96.8% (95%CI: 90.5; 100) in the Cemented group, 94.2% (95%CI: 86.4; 100) in the Uncemented group, and 93.8% (95%CI: 85.4; 100) in the Hybrid group for revision for any reason (p = 0.80). Functional outcome was similar among the groups.

Conclusion

In our cohort of ACS Mobile Bearing TKA, there was no difference between Cemented, Uncemented, and Hybrid Fixation with regard to survival and function at Mid-term follow-up.

Trial registration

Dutch Trial Register (NTR3893), 2013-03-12.

Level of evidence

II.

Validation and Cross-Cultural Adaptation of the Hindi Version of the Oxford Knee Score in Patients With Knee Osteoarthritis

Introduction: Cases of knee osteoarthritis are on the rise in India with an increasingly ageing population. A large number among them shall undergo total knee replacement, so there is a requirement for validated patient-reported outcome measures in the Hindi language. Oxford Knee Score (OKS) is one of the most commonly used patient-reported outcome measure scoring systems. The current study was designed to test and validate cross-cultural adaptation and translate the Hindi version of the Oxford Knee Score (OKS-H). 

Material and Methods: The OKS-H was formulated as per recommendations for cross-cultural adaptation and translation. The OKS was tested on 162 patients with knee osteoarthritis who underwent a total knee replacement. Reliability of the OKS-H was tested using the intraclass correlation coefficient (ICC) and internal consistency was assessed using Cronbach’s alpha. The construct validity was assessed using OKS-H, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and 36-Item Short Form Survey (SF-36) questionnaire. 

Results: The translation was performed with no major difficulty. The OKS was completed by 158 (97.5%) and 157 (96.9%) patients at test and retest, respectively, after one week. With an ICC of 0.87, OKS had shown good reliability. The construct validity obtained against the WOMAC and SF-36 scores was strong (ICC between 0.49 to 0.86).

Conclusion: The translated OKS-H is a reliable and valid instrument for patient-reported outcome measures in cases of knee osteoarthritis opting for total knee arthroplasty.

Return to Sport After Unicompartmental Knee Arthroplasty: A Systematic Review and Meta-analysis

Background:

Patients undergoing unicompartmental knee arthroplasty (UKA) often want to return to sport (RTS) after surgery. However, the time taken to RTS and proportion of patients who RTS after UKA remain unknown.

Purpose:

To determine the time to RTS and proportion of patients who RTS after UKA.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

A search was performed using PubMed, Medline, Embase, SPORTDiscus and the Cochrane Library databases for clinical trials reporting on RTS after UKA published between database inception and September 2021. In addition, a manual search was performed of relevant sports medicine and orthopaedic journals, and bibliographies were reviewed for eligible trials. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were used to undertake this study.

Results:

This meta-analysis included 11 studies (749 patients) that reported on RTS after UKA. The proportion of patients returning to sports increased over time: 6 studies (432 patients) demonstrated an overall pooled proportion of 48.1% (95% CI, 36.3%-60.2%) of patients who returned to sport at 3 months after surgery, while 7 studies (443 patients) demonstrated an overall pooled proportion of 76.5% (95% CI, 63.9%-87.1%) of patients who returned to sport at 6 months after surgery. Overall, 92.7% (95% CI, 85.8%-97.4%) of 749 patients were able to RTS at 4 years after surgery. Overall excellent patient-reported functional outcomes scores and low risk of complications with RTS after UKA were reported.

Conclusion:

The authors found that 48.1% of patients were able to RTS at 3 months after surgery and 76.5% were able to RTS at 6 months after UKA. Pooled proportion analysis showed that >90% of patients undergoing UKA were able to RTS at 48 months after surgery. The majority of patients who were able to RTS after UKA did so at a lower level of intensity than their preoperative level. RTS after UKA was associated with good patient-reported functional outcomes scores and a low risk of complications.

Traditional Chinese-Hong Kong version of Forgotten Joint Score-12 (FJS-12) for patients with osteoarthritis of the knee underwent joint replacement surgery: cross-cultural and sub-cultural adaptation, and validation

Background

A patient-reported outcome (PRO) tool which reflects the outcomes of patients underwent total knee arthroplasty (TKA) are important to be “ceiling effect free” which commonly used PRO tools face. Forgotten joint score-12 (FJS-12) has been proved to reduce or even free from ceiling effect. FJS-12 has been translated to different languages. The objectives of this study are to validate FJS-12 in Traditional Chinese-Hong Kong language and look for the goodness of FJS-12 still exist in this language adapted FJS-12 version.

Methods

FJS-12 was administered to 75 patients whose majority was obese underwent TKA between September 2019 and March 2020. Patients completed 3 sets of questionnaires (FJS-12, Oxford Knee Score (OKS), and Numeric Rating Scale (NRS)) twice, 2 weeks apart. Reliability, internal consistency, responsiveness, test–retest agreement and discriminant validity were evaluated.

Results

Reliability of FJS-12 showed moderate to excellent internal consistency (Cronbach’s α = 0.870). Test–retest reliability of FJS-12 was good (ICC = 0.769). Bland–Altman plot showed good test–retest agreement. Construct validity in terms of correlations between FJS-12 and OKS, and FJS-12 and NRS were moderate at baseline (Pearson’s coefficient r = 0.598) and good at follow-up (r = 0.879). Smallest detectable change (Responsiveness) was higher than MIC. Floor effect was none observed, and ceiling effect was low. Discriminant validity was found to have no significance. BMI (obesity) did not affect FJS-12 outcomes.

Conclusions

The Traditional Chinese-Hong Kong version of FJS-12 showed good test–retest reliability, validity, responsiveness, BMI non-specific, with no floor and low ceiling effects for patients who underwent TKA. Sub-culture differences in individual PRO tools should be considered in certain ethnicities and languages.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05156-5.

Infection and Mechanical Complications Are Risk Factors for New Diagnosis of a Mental Health Disorder After Total Joint Arthroplasty

Background

Prior studies have demonstrated that depression is an independent risk factor for developing a prosthetic joint infection (PJI) after total joint arthroplasty (TJA). To our knowledge, there is no literature examining whether PJI or aseptic failure increases the risk of developing a new mental health diagnosis.

Methods

PearlDiver Patient Database (Colorado Springs, CO) was used to identify 80,826 patients who underwent TJA without a pre-existing diagnosis of depression, anxiety, a stress and/or adjustment disorder, and/or current use of a selective serotonin reuptake inhibitor within the year prior to surgery. The odds of developing a new mental health issue or being prescribed a selective serotonin reuptake inhibitor within 1 year of an uncomplicated TJA was compared to those who developed PJI or mechanical failure within 90 days after TJA as well as to those who subsequently underwent revision surgery within 30 days of either complication using Fisher’s exact test and Baptista-Pike.

Results

A total of 6474 (8%) patients were diagnosed with a new mental health issue after TJA. PJI or mechanical failure led to significantly higher odds of new diagnoses with an odds ratio of 1.67 (95% confidence interval = 1.26, 2.22) and 1.57 (1.24, 2.00), respectively. Undergoing revision surgery for PJI or mechanical failure increased the odds of developing a new mental health diagnosis to 2.10 (1.29, 3.42) and 2.24 (1.36, 3.72), respectively. There was no significant difference comparing those who developed PJI vs those who sustained mechanical complications.

Conclusion

Patients who sustain complications after TJA are at increased odds of receiving a new mental health diagnosis, an effect further amplified if revision surgery is required.

Effect of Preoperative Diabetes on the Achievement of Forgotten Knee Status in Patients with Total Knee Arthroplasty

BACKGROUND

Forgotten knee is the terminology which is used to describe a post-TKA patient who is completely unaware of his knee implant. The aim of the study is to determine whether preoperative diabetes negatively influences the achievement of forgotten knee status.

METHODS

This is a retrospective cohort study. 300 patients (240 F:60 M) were studied. Patients were evaluated by an independent observer with FJS-12 score 2 weeks preop and at 6 weeks and 12 months after the operation. The patients with a FJS-12 score of ≥ 55 were considered to have achieved forgotten knee status. Out of 240 females, 96 had diabetes and out of 60 males, 18 had diabetes. Preoperative factors such as preop HBA1c, ROM, degree of deformity, VAS score and other associated co morbidities and postoperative factors such as HBA1c, ROM and hip-knee-ankle alignment were studied. Study was started with null hypothesis. The statistical difference was measured with Binominal proportion test and comparison of means t test.

RESULTS

96 out of 144 non-diabetic females (66.67%) and 51 out of 96 diabetic females (53%) achieved forgotten knee status (statistically significant, p value = 0.0336, Binominal proportion test). 27 out of 42 (65%) non-diabetic males and 12 out 18 diabetic males (66%) achieved forgotten knee status (p value = 0.9411). The FJS-12 score at 1 year for non-diabetic females and diabetic females was 58.6 mean ± 12.6 SD and 53.8 ± 17.6, respectively, which is statistically significant, p value 0.0145. The FJS-12 at 1 year in non-diabetic and diabetic males was 60.1 ± 14.8 and 59.6 ± 17.3, respectively, p value = 0.9097.

CONCLUSION

Diabetic females have less chance of achieving a forgotten knee status than non-diabetic females. This understanding will help the operating surgeon in the preoperative patient counseling and modify the patient expectations.

A clinical review of robotic navigation in total knee arthroplasty: historical systems to modern design

Robotic-assisted total knee arthroplasty (RA-TKA) has shown improved reproducibility and precision in mechanical alignment restoration, with improvement in early functional outcomes and 90-day episode of care cost savings compared to conventional TKA in some studies. However, its value is still to be determined.

Current studies of RA-TKA systems are limited by short-term follow-up and significant heterogeneity of the available systems.

In today’s paradigm shift towards an increased emphasis on quality of care while curtailing costs, providing value-based care is the primary goal for healthcare systems and clinicians. As robotic technology continues to develop, longer-term studies evaluating implant survivorship and complications will determine whether the initial capital is offset by improved outcomes.

Future studies will have to determine the value of RA-TKA based on longer-term survivorships, patient-reported outcome measures, functional outcomes, and patient satisfaction measures.

Cite this article: EFORT Open Rev 2021;6:252-269. DOI: 10.1302/2058-5241.6.200071

Education, engagement and provision of empathy by trained counselor enhances the patient satisfaction after Total Knee Arthroplasty

BACKGROUND

One of the major concerns following Total Knee Arthroplasty (TKA) surgery is patient satisfaction. Hence, this study sought to assess the effect of patient education, engagement and provision of empathy delivered by trained counselor on patient satisfaction.

METHODS

All the patients included in the study were randomly allocated to two groups: Patients who received counseling from trained personnel during pre-, peri- and post-TKA phase constituted group-A (n = 100) whereas patients who were advised by the surgeon before the procedure constituted group-B (n = 100). All the patients who were counseled by trained personnel continued to receive counseling up to six months following TKA surgery. Patients belonging to group-A were provided counseling pertaining to education related to TKA procedure, the modalities of pain management and post-TKA ambulation regimen. Patient satisfaction was measured with Forgotten Joint Score-12 (FJS-12) and consumer gap (defined as the difference between patient perception and expectation) was recorded by an independent observer after 52-week of the TKA procedure.

RESULTS

Patients belong to group-A had higher satisfaction as compared to those in group-B as evident by statistically higher FJS-12 score (64.5 ± 16.4 vs. 59.4 ± 17.9; p = 0.0369). There was statistically significant difference observed in consumer gap between group-A (6%) and group-B (16%) (p = 0.0242).

CONCLUSIONS

The results of the study are encouraging to employ counseling by trained personnel during pre-, peri- and post-TKA phases as to improve patient satisfaction and reduce consumer gap.

Discrepant histological diagnoses: A cause of early low FJS-12 score and if untreated, unhappy Total Knee Arthroplasty patient

PURPOSE

Total Knee Arthroplasty (TKA) is one of the most successful operations in orthopedics. Still, a sizable percentage of patients (20%) remain dissatisfied after a well-executed TKA. The study aims to examine the excised synovium from the suprapatellar region in osteoarthritic knees during TKA and evaluate the histopathology (HP) report to know whether discrepant diagnoses affect the Forgotten Joint Score-12 at various time intervals.

METHODS

This is a prospective cohort study. Two hundred (160 female; 40 male) end-stage osteoarthritis patients who underwent primary TKA were studied. An inclusion criterion was patient with end-stage osteoarthritis. Clinically and serologically proven rheumatoid arthritis patients were excluded from the study. The synovium excised during the TKA procedure was sent for the HP examination. The statistical significance was measured with the Chi-square test and two-sample t-test.

RESULTS

A total of 184 out of the 200 patients (92%) knee synovium showed HP features of osteoarthritis. The discordant diagnoses and discrepant diagnosis rate was 8% and 7%, respectively, which is statistically significant by Chi-square test (p value < 0.0001 and p value = 0.0001). 14 of the patients (12 F:2 M) showed histological features of inflammatory/rheumatoid arthritis who were treated, two patients (all female) showed HP features of villonodular synovitis. The mean (SD) improvement in FJS-12 at six weeks in the concordant group (25.3 [17.6]) is significantly more than the discrepant group (15.3 [12.5]), p-value 0.0385.

CONCLUSION

8% of our patients exhibited unexpected results. The study showed a 7% rate of discrepant diagnosis. This discrepant diagnosis if missed and untreated, would have affected the function and long-term survival of the implanted TKA.

Knee replacement outcome predicted by physiotherapists: a prospective cohort study

Background

Knee arthroplasty (KA) is commonly used for osteoarthritis of the knee joint and it is a highly successful procedure. Still, KA leaves 20% of patients dissatisfied with their outcome. The purpose of this study was to determine if a prognosis made by physiotherapists at the orthopaedic wards during the first post-operative days could predict the 6- and 12-months outcome of KA.

Methods

Physiotherapists at two orthopaedic wards in Denmark were asked to predict the 6- and 12-months outcome of the KA patients they have treated post-operatively on a 0–10 scale (10 representing the best prognosis). At 6 and 12 months post-operatively the patients answered the Oxford Knee Score (OKS), EuroQol 5D-3L and Patient Acceptable Symptom State (PASS). Multivariable logistic regression analyses were performed to assess the prediction of PASS and treatment success. We assessed predictive performance by examining measures of calibration and discrimination.

Results

A total of 361 patients were included. The models for PASS and Treatment Success showed poor to acceptable discriminative values (OR between 1.47 and 1.92 and areas under the curves of 0.62–0.73), however the calibration plots indicated significant uncertainties in the prediction.

Conclusion

Physiotherapists prognoses of recovery after KA are associated with 6- and 12-months patient reported outcomes and satisfaction but have weak predictive value. This study suggests that physiotherapists’ prognoses may be useful as an additional source of information when identifying patients in need of additional post-operative care.

Home physiotherapy with vs. without supervision of physiotherapist for assessing manipulation under anaesthesia after total knee arthroplasty

Abstract

The aim of this retrospective cohort study was to compare home physiotherapy with or without supervision of physiotherapist for assessing manipulation under anaesthesia after total knee arthroplasty.

Methods

A total of 900 patients (including 810 females and 90 males) who had undergone total knee arthroplasty were divided into group A (n = 300) and group B (n = 600). Patients in group A had home physiotherapy on their own after discharge from hospital. The physiotherapist did not visit them at home. Patients in group B received home physiotherapy under supervision of physiotherapist for 6 weeks after discharge from hospital. Patients’ age, range of motion of the knee, and forgotten joint score-12 were assessed. A p < 0.05 was considered statistically significant.

Results

In group A, the mean age was 69.1 ± 14.3 years (range: 58 to 82 years); in group B, the mean age was 66.5 ± 15.7 years (range: 56 to 83 years) (p > 0.05). Preoperatively, the mean range of motion of the knee in group A and B was 95.8° ± 18.1° and 95.4° ± 17.8°, respectively (p > 0.05). The mean forgotten joint score-12 of group A and B were 11.90 ± 11.3 and 11.72 ± 12.1 (p > 0.05), respectively. Six weeks after total knee arthroplasty, the mean ROM of the knee in group A and B was 109.7° ± 22.3° and 121° ± 21.5°, respectively (p < 0.05). The mean postoperative forgotten joint score-12 of the group A and B was 24.5 ± 16.4 and 25.6 ± 17.4, respectively (p > 0.05). The rate of manipulation under anaesthesia was 3% in group A and 0.2% in group B (p < 0.05).

Conclusion

After total knee arthroplasty, frequent physiotherapist’s instruction helps the patients improve knee exercises and therefore decrease the risk of revision surgery. The home physiotherapy under supervision of physiotherapist lowers the rate of manipulation under anaesthesia.

Level of evidence

Therapeutic study, Level IIa.

The Combination of Exercise and Manual Therapy Versus Exercise Alone in Total Knee Arthroplasty Rehabilitation: A Randomized Controlled Clinical Trial

BACKGROUND

Total knee arthroplasty (TKA) is one of the most commonly performed orthopedic surgeries in the lower extremity. However, patient dissatisfaction and functional disability are mostly experienced because of pain and limited range of motion (ROM). Although manual therapy is commonly implemented to improve ROM and modulate pain in the management of musculoskeletal disorders, there is a lack of evidence about its clinical effectiveness on postoperative TKA rehabilitation.

OBJECTIVE

To investigate the effectiveness of an exercise program combined with manual therapy compared with an exercise program only for pain, ROM, function, quality of life, and patient satisfaction outcomes.

DESIGN

A randomized controlled clinical trial.

SETTING

Rehabilitation unit of a university hospital.

PARTICIPANTS

Forty-two patients (68.45 ± 6.3 years) scheduled for unilateral TKA as a treatment of severe osteoarthritis.

INTERVENTIONS

Joint and soft tissue mobilizations in addition to exercise therapy were provided to the mobilization group (n = 21) while the control group received exercise therapy only (n = 21).

MAIN OUTCOME MEASURES

The outcome measures were numeric pain-rating scale, knee ROMs, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, 10-meter walk test (10MWT), 5-times sit to stand test (5SST), and Short Form-12 (SF-12).

RESULTS

Improvements in pain outcomes were significantly higher in the mobilization group than in the control group (P = .001, F [3, 33] = 7.06) and the between-group difference in change score was 1.3 points (P = .001). Although the between-group difference in change score was 12.8° for knee flexion at 2 months (P = .001), the overall group-by-time interactions were not significant for flexion and extension ROMs (P = .175, F [3, 33] = 1.75 and P = .57, F [2, 34] = 0.56, respectively). Additionally, there were statistically meaningful group-by-time interactions on total WOMAC score (P = .006, F [2, 34] = 5.29), 10MWT (P = .002, F [3, 33] = 5.98), and SF-12 mental component summary (P = .01, F [2, 34] = 4.92) favoring the mobilization group. Also, patient satisfaction was higher in the mobilization group (P = .02).

CONCLUSIONS

A structured exercise program combined with manual therapy can be more beneficial in improving pain, function, and patient satisfaction compared to exercise program alone for postoperative TKA patients.

Robotic Total Knee Arthroplasty vs Conventional Total Knee Arthroplasty: A Nationwide Database Study

Background

As robot-assisted equipment is continuously being used in orthopaedic surgery, the past few decades have seen an increase in the usage of robotics for total knee arthroplasty (TKA). Thus, the purpose of the present study is to investigate the differences between robotic TKA and nonrobotic TKA on perioperative and postoperative complications and opioid consumption.

Methods

An administrative database was queried from 2010 to Q2 of 2017 for primary TKAs performed via robot-assisted surgery vs non-robot-assisted surgery. Systemic and joint complications and average morphine milligram equivalents were collected and compared with statistical analysis.

Results

Patients in the nonrobotic TKA cohort had higher levels of prosthetic revision at 1-year after discharge (P < .05) and higher levels of manipulation under anesthesia at 90 days and 1-year after discharge (P < .05). Furthermore, those in the nonrobotic TKA cohort had increased occurrences of deep vein thrombosis, altered mental status, pulmonary embolism, anemia, acute renal failure, cerebrovascular event, pneumonia, respiratory failure, and urinary tract infection during the inpatient hospital stay (all P < .05) and at 90 days after discharge (all P < .05). All of these categories remained statistically increased at the 90-days postdischarge date, except pneumonia and stroke. Patients in the nonrobotic TKA cohort had higher levels of average morphine milligram equivalents consumption at all time periods measured (P < .001).

Conclusions

In the present study, the use of robotics for TKA found lower revision rates, lower incidences of manipulation under anesthesia, decreased occurrence of systemic complications, and lower opiate consumption for postoperative pain management. Future studies should look to further examine the long-term outcomes for patients undergoing robot-assisted TKA.

Level of Evidence

Level III.

Feasibility of Collecting Multiple Patient-Reported Outcome Measures Alongside the Dutch Arthroplasty Register

Background:

Compliance rates with patient-reported outcome measures (PROMs) collected alongside arthroplasty registries vary in the literature. We described the feasibility of a routinely collected set PROMs alongside the Dutch Arthroplasty Register.

Methods:

The longitudinal Leiden Orthopaedics Outcomes of OsteoArthritis Study is a multicenter (7 hospitals), observational study including patients undergoing total hip or total knee arthroplasty (THA or TKA). A set of PROMs: Short Form-12, EuroQol 5 Dimensions, Hip/Knee injury and Osteoarthritis Outcome Score, Oxford Hip/Knee Score was collected preoperatively and at 6, 12, 24 months, and every 2 years thereafter. Participation rates and response rates were recorded.

Results:

Between June 2012 and December 2014, 1796 THA and 1636 TKA patients were invited, of whom 1043 THA (58%; mean age 68 years [standard deviation, SD: 10]) and 970 TKA patients (59%; mean age 71 years [SD 9.5]) participated in the study. At 6 months, 35 THA/38 TKA patients were lost to follow-up. Response rates were 90% for THA (898/1000) and 89% for TKA (827/932) participants. At 1 and 2 years, 8 and 18 THA and 17 and 11 TKA patients were lost to follow-up, respectively. The response rates among those eligible were 87% (866/992) and 84% (812/972) for THA and 84% (771/917) and 83% (756/906) for TKA patients, respectively. The 2-year questionnaire was completed by 78.5% of the included THA patients and by 77.9% of the included TKA patients.

Conclusions:

About 60% of patients undergoing THA or TKA complete PROMs preoperatively, with more than 80% returning follow-up PROMs. To increase the participation rates, more efforts concerning the initial recruitment of patients are needed.

Core Outcome Measurement Instruments for Clinical Trials of Total Knee Arthroplasty: A Systematic Review

(1) Background: We have updated knowledge of the psychometric qualities of patient-reported outcome measures and, for the first time, systematically reviewed and compared the psychometric qualities of physical tests for patients with knee osteoarthritis who are undergoing total knee arthroplasty. This work was conducted to facilitate the choice of the most appropriate instruments to use in studies and clinical practice. (2) Methods: A search of medical databases up to December 2019 identified the studies and thus the instruments used. The quality of the measurement properties was assessed by the Bot et al. criteria. (3) Results: We identified 20 studies involving 25 instruments. Half of the instruments were questionnaires (n = 13). Among the condition-specific instruments, the Oxford knee score, Knee injury and Osteoarthritis Outcomes Score, and the Western Ontario and McMaster Universities Osteoarthritis index had the highest overall scores. Concerning generic tools, the Medical Outcomes Study Short-Form 36 (SF-36) or SF-12 obtained the highest overall score. For patient-specific tools, the Hospital Anxiety and Depression Scale ranked the highest. Some physical tests seemed robust in psychometric properties: 6-min Walk Test, five times Sit-To-Stand test, Timed Up and Go test strength testing of knee flexor/extensor by isometric or isokinetic dynamometer and Pressure Pain Threshold. (4) Conclusion: To make stronger recommendations, key areas such as reproducibility, responsiveness to clinical change, and minimal important change still need more rigorous evaluations. Some promising physical tests (e.g., actimetry) lack validation and require rigorous studies to be used as a core set of outcomes in future studies.

Eccentric and Concentric Resistance Exercise Comparison for Knee Osteoarthritis

INTRODUCTION

This study aimed to compare the efficacy of eccentrically focused resistance exercise (ECC RT) to concentrically focused resistance exercise (CNC RT) on knee osteoarthritis (OA) symptoms and strength.

METHODS

Ninety participants consented. Participants were randomized to CNC RT, ECC RT, or a wait-list, no-exercise control group. Four months of supervised exercise training was completed using traditional weight machines (CNC RT) or modified-matched machines that overloaded the eccentric action (ECC RT). Main outcomes included one-repetition maximal strength (knee extension, leg flexion, and leg press), weekly rate of strength gain, Western Ontario and McMaster University Osteoarthritis Index (WOMAC) total score and subscores.

RESULTS

Fifty-four participants (60-85 yr, 61% women) completed the study. Both CNC RT and ECC RT groups showed 16%-28% improvement relative to the wait-list, no-exercise control group (P = 0.003-0.005) for all leg strength measures. The rate of weekly strength gain was greater for CNC RT than for ECC RT for leg press and knee flexion (by 2.9%-4.8%; both, P < 0.05) but not knee extension (0.7%; P = 0.38). There were no significant differences in WOMAC total and subscores across groups over time. Leg press strength change was the greatest contributor to change in WOMAC total scores (R = 0.223). The change in knee flexion strength from baseline to month 4 was a significant predictor of the change in WOMAC pain subscore (F ratio = 4.84, df = 45, P = 0.032). Both modes of strength training were well tolerated.

CONCLUSIONS

Both resistance training types effectively increased leg strength. Knee flexion and knee extension muscle strength can modify function and pain symptoms irrespective of muscle contraction type. Which mode to pick could be determined by preference, goals, tolerance to the contraction type, and equipment availability.

Individual Gait Features Are Associated with Clinical Improvement After Total Knee Arthroplasty

Background:

Over 20% of patients do not report clinically relevant pain relief or functional improvements after total knee arthroplasty (TKA). The aim of this study was to investigate the effect of demographics, pre-TKA knee-joint biomechanics, and postoperative changes in knee biomechanics on meaningful improvements in self-reported pain and function after TKA.

Methods:

Forty-six patients underwent 3-dimensional gait analysis and completed the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire before and 1 year after TKA. Response to treatment in terms of pain relief and functional improvement (“pain and function responders”) was defined as improvements in WOMAC scores that met minimal clinically important difference thresholds in the pain and function domains. Differences between responder and non-responder demographics, severity of the osteoarthritis as seen radiographically, and knee kinematics and kinetics before TKA were explored using the t test and Mann-Whitney U test. Correlations and regression models were used to examine demographics, baseline knee kinematics and kinetics, and post-TKA kinematic and kinetic improvements associated with being a pain responder and a function responder separately. Analyses were conducted using a hypothesis-driving approach.

Results:

Of the 46 patients, 34 were pain responders and 36 were function responders. Preoperatively, both responder groups had a higher radiographic severity (Kellgren-Lawrence) grade (p = 0.03) and pain responders were more symptomatic according to their WOMAC score (p < 0.04). Less preoperative stance-phase flexion-extension angle range (p ≤ 0.03), lower preoperative stance-phase adduction (varus) angle magnitude (p = 0.01), and less postoperative reduction in the adduction angle magnitude (p ≤ 0.009) were independently associated with more self-reported improvement in pain and function.

Conclusions:

Patients with a higher radiographic severity grade, with specific frontal and sagittal knee kinematic patterns during gait before TKA, and who demonstrated less reduction in frontal plane angles during gait after TKA had greater self-reported pain and function score improvements after standard TKA. Gait analysis may aid preoperative identification of kinematic subgroups associated with self-reported improvements after TKA, and provide evidence that may inform triaging, surgical planning, and expectation management strategies.

Level of Evidence:

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Additional effect of neuromuscular electrical stimulation on knee extension lag, pain and knee range of motion in immediate postsurgical phase (0-2 weeks) in primary total knee arthroplasty patient

Background

There are various studies on younger adults which have shown that neuromuscular electrical stimulation (NMES), at sufficient intensities, combined with active exercises had better improvement in muscle strength and functional performance than exercises alone. But very limited research is available for giving NMES in the early acute stages post total knee arthroplasty (TKA). So, the short-term effect of NMES had not yet been researched upon widely. As there were conflicting evidences in giving NMES post TKA, this study was proposed to assess the short-term effect of early NMES on knee joint pain, range of motion (ROM) and extension lag on patients undergoing bilateral TKA.

Methods

The study included 28 bilateral TKA patients following osteoarthritis (OA) knee within the age group of 50-75 years (60.82±5.69). The knees of 28 bilaterally operated patients were randomly divided into two groups; 1 knee was allocated in the experimental group and the other knee of the same patient became the control. The experimental group was given NMES with exercises, while the control group was given only exercises for 7 days. The patients were asked to continue to follow exercises even after the discharge, i.e., beyond 7 days. The patients were measured for pain; knee flexion ROM and extensor lag both before and after intervention.

Results

There was a significant improvement in pain, knee ROM and extensor lag post intervention P<0.05 in both the groups. But there was no significant difference between the groups with respect to pain, knee ROM and extensor lag, P>0.05.

Conclusions

The NMES and exercises worked equally in case of patients operated for TKA. Hence our results concluded that there was no additional effect of NMES on extensor lag, knee ROM and pain when applied for 7 days in patients operated with TKA.

Association Between Femoral Component Sagittal Positioning and Anterior Knee Pain in Total Knee Arthroplasty: A 10-Year Case-Control Follow-up Study of a Cruciate-Retaining Single-Radius Design

BACKGROUND

Anterior knee pain is the most common complication of total knee arthroplasty (TKA). The purpose of this study was to assess whether sagittal femoral component position is an independent predictor of anterior knee pain after cruciate-retaining single-radius TKA without routine patellar resurfacing.

METHODS

A prospective cohort study of 297 cruciate-retaining single-radius TKAs performed in 2006 and 2007 without routine patellar resurfacing identified 73 patients (25%) with anterior knee pain and 89 (30%) with no pain (controls) at 10 years. Patients were assessed preoperatively and at 1, 5, and 10 years postoperatively using patient-reported outcome measures (PROMs), including the Short Form-12 (SF-12), Oxford Knee Score (OKS), and satisfaction and expectation questionnaires. Variables that were assessed as predictors of anterior knee pain included demographic data, the indication for the TKA, early complications, stiffness requiring manipulation under anesthesia, and radiographic criteria (implant alignment, Insall-Salvati ratio, posterior condylar offset ratio, and anterior femoral offset ratio).

RESULTS

The 73 patients with anterior knee pain (mean age, 67.0 years [range, 38 to 82 years]; 48 [66%] female) had a mean visual analog scale (VAS) score of 34.3 (range, 5 to 100) compared with 0 for the 89 patients with no pain (mean age, 66.5 years [range, 41 to 82 years]; 60 [67%] female). The patients with anterior knee pain had mean femoral component flexion of -0.6° (95% confidence interval [CI] = -1.5° to 0.3°), which differed significantly from the value for the patients with no pain (1.42° [95% CI = 0.9° to 2.0°]; p < 0.001). The patients with and those without anterior knee pain also differed significantly with regard to the mean anterior femoral offset ratio (17.2% [95% CI = 15.6% to 18.8%] compared with 13.3% [95% CI = 11.1% to 15.5%]; p = 0.005) and the mean medial proximal tibial angle (89.7° [95% CI = 89.2° to 90.1°] compared with 88.9° [95% CI = 88.4° to 89.3°]; p = 0.009). All PROMs were worse in the anterior knee pain group at 10 years (p < 0.05), and the OKSs were worse at 1, 5, and 10 years (p < 0.05). Multivariate analysis confirmed femoral component flexion, the medial proximal tibial angle, and an Insall-Salvati ratio of <0.8 (patella baja) as independent predictors of anterior knee pain (R = 0.263). Femoral component extension of ≥0.5° predicted anterior knee pain with 87% sensitivity.

CONCLUSIONS

In our study, 25% of patients had anterior knee pain at 10 years following a single-radius cruciate-retaining TKA without routine patellar resurfacing. Sagittal plane positioning and alignment of the femoral component were associated with long-term anterior knee pain, with femoral component extension being a major risk factor.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

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.

Effect of Deep Slow Breathing on Pain-Related Variables in Osteoarthritis

This study evaluated the effect of a six-week deep slow breathing (DSB) program on pain, physical function, and heart rate variability (HRV) in subjects with lower extremity joint pain. Twenty subjects were assigned into training (n = 10) and control (n = 10) groups. The training group participated in a six-week DSB program consisting of weekly training sessions and at-home breathing exercises. DSB exercises focused on prolonging the exhalation and the pause following exhalation. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) was used to assess pain and physical function, and HRV data were obtained before and after intervention. Results revealed no significant interactions between group and time for any of the variables. There was no significant main effect for group, but there was a significant main effect (p < 0.025) and a large effect size for time on both pain (η _p ² = 0.454) and physical function (η _p ² = 0.506). There were no significant main effects (p > 0.017) for group and time on LF power (group η _p ² = 0.039, time η _p ² = 0.061), HF power (group η _p ² = 0.039, time η _p ² = 0.039), and LF/HF ratio (group η _p ² = 0.036, time η _p ² = 0.169). Results indicated that the six-week DSB program was not sufficient to alleviate pain or improve physical function in subjects with lower extremity joint pain. Although the pain was not alleviated, other beneficial effects such as better coping with the pain were reported in the majority of training subjects. As this is the first study to examine the use of DSB for lower extremity joint pain and dysfunction, further research is needed to investigate the efficacy and applicability of DSB.

Radiological grading of osteoarthritis on Rosenberg view has a significant correlation with clinical outcomes after medial open-wedge high-tibial osteotomy

PURPOSE

To determine the classification scheme for osteoarthritis severity grading that most closely correlates with postoperative clinical outcomes and to identify the positive and negative prognostic factors for medial open-wedge high-tibial osteotomy (OWHTO).

METHODS

Seventy-nine consecutive patients with primary varus osteoarthritis were treated using OWHTO. Arthritic grading was determined by arthroscopic assessment according to the modified Outerbridge classification and by radiographic classification according to the Kellgren-Lawrence (KL) grading scale on standing anteroposterior (AP) and 45° posteroanterior (PA) flexion weight-bearing radiography. Clinical outcome was assessed using the Oxford Knee Score (OKS), which was evaluated both preoperatively and at the postoperative 2-year follow-up after OWHTO. Multivariate regression analyses were used to explore and quantify the influence of baseline patient demographics, variables related to arthroscopic and radiological grades of arthritis, as well as postoperative alignment changes on the OKS.

RESULTS

At the 2-year follow-up, the mean OKS had improved from 20 ± 4 to 39 ± 5 points (p < 0.001). The average mechanical femorotibial and mechanical medial proximal tibial angle (MPTA) changed from 6.9° ± 3.4° to valgus 2.7° ± 2.8° and from 85.6° ± 2.4° to 92.9° ± 3.7° (all p < 0.001). The osteoarthritis severity grade based on the KL scale was 2.4 ± 0.9 on standing AP radiography, 2.8 ± 0.9 on 45° PA flexion weight-bearing radiography (p = 0.003), and 3.4 ± 0.7 according to the modified Outerbridge classification. In the multivariate analyses, the KL grade on 45° PA flexion weight-bearing radiography (p = 0.01) and postoperative MPTA (p = 0.01) showed significant negative correlations with postoperative OKS at the 2-year follow-up.

CONCLUSION

The KL grading system based on 45° PA flexion weight-bearing radiography showed the strongest significant negative correlation with postoperative OKS after the OWHTO procedure using three different common OA classification schemes, which should be considered to determine the surgical indication of HTO. The KL grading system based on 45° PA flexion weight-bearing radiography showed the strongest correlation with high-tibial osteotomy-surgical indications and the counselling of patients with advanced osteoarthritis.

LEVEL OF EVIDENCE

IV.

Short term patient outcomes after total knee arthroplasty: Does the implant matter?

BACKGROUND

Newer implants for total knee arthroplasty (TKA) often gain market share at higher cost with little patient-reported and long-term clinical data. We compared outcomes after TKA using two different implants: DePuy PFC Sigma and Attune.

METHODS

Using a prospective data repository from an academic tertiary medical center, we analyzed 2116 TKAs (1603 Sigma and 513 Attune) from April 2011 through July 2016. Outcomes included length of surgery, length of stay, facility discharge, 90-day reoperation, range of motion (ROM) change, and patient-reported physical function (PCS).

RESULTS

There was no difference in length of surgery (Attune -2.87 min, P = 0.143). Implant type was not associated with extended LOS (>3 days) (OR 0.80, P = 0.439). There was no difference in facility discharge (OR 0.65, P = 0.103). Unadjusted 90-day reoperations were 0.3% for Sigma and 1.0% for Attune cohorts (P = 0.158). Sigma implants were associated with more ROM improvement in unadjusted analyses (+2.1 degree improvement P = 0.031). Fifty nine percent of the Sigma cohort and 49% of the Attune cohort achieved the minimal clinically important (MCID) change for PCS improvement, although there was no adjusted difference in achieving MCID (Attune OR 0.84, P = 0.435). There was no adjusted difference in absolute PCS improvement (Attune +0.12 score, P = 0.864).

CONCLUSIONS

Our data show no difference in physical function and most outcomes between Sigma and Attune. Attune implants had shorter absolute LOS, but there were no differences in extended LOS.

Rheumatoid Arthritis Patients Achieve Better Satisfaction but Lower Functional Activities as Compared to Osteoarthritis Patients After Total Knee Arthroplasty

BACKGROUND

Recently, poor patient satisfaction after total knee arthroplasty (TKA) has gained attention mainly in osteoarthritis (OA) patients; however, satisfaction after TKA remains to be understood in rheumatoid arthritis (RA) patients. This study aimed to examine satisfaction and function after RA TKA using patient-reported outcome measures and to compare the results with those of OA-TKA.

METHODS

This study enrolled 534 TKAs of 501 patients consisting of 75 TKAs of 70 RA patients and 459 TKAs of 431 OA patients. Data of patient-reported outcome measures such as new Knee Society Score 2011, Pain Catastrophizing Scale, and Pain DETECT Score were collected at 2 years. Multiple regression analysis was performed with Knee Society Score satisfaction score set as a dependent variable in order to clarify factors affecting patient satisfaction. Principle component analysis was performed, and satisfaction and function components were compared between RA and OA.

RESULTS

All activity scores were significantly lower in RA TKA than in OA TKA, whereas the range of motion and patient satisfaction scores were significantly better in RA TKA than in OA TKA. Scores for symptom, expectation, basic activity, and discretional activity positively affected patient satisfaction (P < .001), while Pain Catastrophizing Scale negatively did (P = .021). Importantly, diagnosis of RA itself pushed up the patient satisfaction score by 1.5 points. Principle component analysis revealed that RA TKA achieved significantly higher satisfaction component (P = .001), but lower function component (P < .0001) compared to OA TKA.

CONCLUSION

Patient satisfaction was better but functional activity was lower in RA than in OA. As poor functional activity was evident preoperatively in RA patients, to improve functional outcome should be future challenge for RA TKA.

Excellent 10-year patient-reported outcomes and survival in a single-radius, cruciate-retaining total knee arthroplasty

PURPOSE

Over 2 million Triathlon single-radius total knee arthroplasties (TKAs) have been implanted worldwide. This study reports the 10-year survival and patient-reported outcome of the Triathlon TKA in a single independent centre.

METHODS

From 2006 to 2007, 462 consecutive cruciate-retaining Triathlon TKAs were implanted in 426 patients (median age 69 (21-89), 289 (62.5%) female). Patellae were not routinely resurfaced. Patient-reported outcome measures (SF-12, Oxford Knee Scores (OKS), satisfaction) were assessed preoperatively and at 1, 5 and 10 years when radiographs were reviewed. Forgotten Joint Scores (FJS) were collected at 10 years. Kaplan-Meier survival analysis was performed.

RESULTS

At 10-11.6 years, 123 patients (128 TKAs) had died and 8 TKAs were lost to follow-up. There were four aseptic failures (two cases of tibial loosening, two cases of instability) and four septic failures requiring revision. Symptomatic aseptic radiographic loosening was present in three further cases at 11 years. Four (1%) patellae were secondarily resurfaced. OKS score improved by 17.7 ± 9.7 points at 1 year (p < 0.001), and was maintained at 34.7 ± 9.6 at 10 years with FJS 48.5 ± 31.4. Patient satisfaction was 88% at each timepoint. Ten-year survival was 97.9% (95% confidence interval 96.5-99.3) for revision for any reason, 98.9% (97.7-100) for mechanical failure, and 98.6% (97.4-99.8) for aseptic loosening (symptomatic radiographic or revised).

CONCLUSION

The Triathlon TKA continues to show excellent longer-term results with high implant survivorship, low rates of aseptic failure, consistently maintained PROMs and excellent patient satisfaction rates of 88% at 10 years.

LEVEL OF EVIDENCE

II, Prospective cohort study.

Computational analysis of customized cruciate retaining total knee arthroplasty restoration of native knee joint biomechanics

The purpose of this study was to verify if customized prosthesis better preserves the native knee joint kinematics and provides lower contact stress on the polyethylene (PE) insert owing to the wider bone preservation than that of standard off-the-shelf prosthesis in posterior cruciate-retaining type total knee arthroplasty (TKA). Validated finite element (FE) models for were developed to evaluate the knee joint kinematics and contact stress on the PE insert after TKA with customized and standard off-the-shelf (OTS) prostheses as well as in normal healthy knee through FE analysis under dynamic loading conditions. The contact stresses on the customized prosthesis decreased by 18% and 8% under gait cycle loading conditions, and 24% and 9% under deep-knee-bend loading conditions, in the medial and lateral sides of the PE insert, respectively, compared with the standard OTS prosthesis. The anterior-posterior translation and internal-external (IE) rotation in customized TKA were more similar to native knee joint behaviors compared with standard OTS TKA under gait loading conditions. The difference from normal knee kinematics was lower for femoral rollback and IE rotation in customized TKA than in standard OTS TKA in the deep-knee-bend condition. In general, customized prostheses achieve kinematics that are close to those of the native healthy knee joint and have better contact stresses than standard OTS prostheses in gait and deep-knee-bend loading conditions.

Slow gait speed after bilateral total knee arthroplasty is associated with suboptimal improvement of knee biomechanics

PURPOSE

The aim of this study was to investigate gait speed changes 2 years after bilateral total knee arthroplasty (TKA) and identify kinetic and kinematic factors associated with such changes by comparing patients with age- and sex-matched controls.

METHODS

The study group included 34 female patients with end-stage knee osteoarthritis (OA) who underwent bilateral TKA and 42 age- and sex-matched controls without knee pain or OA. Standard TKA was performed on all arthritic patients with placement of posterior stabilized fixed-bearing implants. Kinetic and kinematic parameters were evaluated using a commercial optoelectric gait analysis system. Gait speed, kinetic and kinematic changes and determinants of speed were assessed via principal component analysis and multiple regression analysis.

RESULTS

The average gait speed of an arthritic patient was 90.2 ± 18.4 cm/s and improved to 96.0 ± 12.3 cm/s after TKA (p = 0.032). However, the speed remained slower than that of controls (111.2 ± 8.2 cm/s, p < 0.001). With regard to kinetics, the peak knee extension moment (KEM) generated by the quadriceps was unchanged after TKA and weaker than that of controls (p < 0.001). The proportions of KEM contributing to the total sagittal moment were also smaller in the pre-/post-operative groups than in the control group (13-14% vs. 19%). On the other hand, the ankle plantar flexion moment (APFM) was increased after TKA (p = 0.007) and its proportion of the total sagittal moment was greater than in controls (46% vs. 42%). With regard to kinematics, knee range of motion (ROM) improved after TKA (p = 0.025), but was smaller than that of controls (p < 0.001). In controls, gait speed was determined principally by hip and knee joint moments. However, in the TKA group, speed was determined by the knee ROM and APFM.

CONCLUSIONS

Despite showing improvement, the gait speed of TKA patients remained slower than that of controls. Slow gait speed after bilateral TKA was associated with suboptimal improvement of knee biomechanics. Quadriceps strengthening exercises and the achievement of greater ROM during gait are advised for the further improvement of gait speed.

LEVEL OF EVIDENCE

Retrospective cohort study, Level III.

Evaluation of the Factors Affecting Concerns and Expectations of Patients Undergoing Total Knee Arthroplasty in China

Background

The aim of this study was to assess the level of concern and expectations of patients and their families of total knee arthroplasty (TKA), peri-operative procedures, postoperative rehabilitation, and outcome in a Chinese population.

Material/Methods

The study recruited 133 patients with osteoarthritis, scheduled to undergo primary elective TKA. Before surgery, the surgeon completed the Hospital for Special Surgery (HSS) Knee Score questionnaire on pain, function, range of motion (ROM), and muscle strength. There were 128 patients and 127 family members (spouses, sons, or daughters) who completed the 24-item Western Ontario and McMaster University Osteoarthritis Index (WOMAC) questionnaire on pain, stiffness, and physical function, and also a 61-item questionnaire that included direct questions on their concerns and expectations on TKA and its outcome, using scores of: 1, not concerned; 2, somewhat concerned; 3, very concerned; and 4, extremely concerned.

Results

The five greatest pre-operative concerns for patients included the degree of postoperative mobility; the experience and expertise of their surgeon; the risk of failure of TKA; the duration of the joint implant; and their expected degree of postoperative independence. Scores for Chinese patients indicated a higher level of concern compared with Western patients. Family members were significantly more concerned than patients regarding the postoperative restoration of knee function and alleviation of pain (p=0.001), the ability to squat (p=0.049) and to kneel (p=0.039).

Conclusions

Communicating pre-operative information on TKA might result in realistic expectations for patients and their families, alleviate concerns, and improve relationships between doctors and patients.

Asymptomatic population reference values for three knee patient-reported outcomes measures: evaluation of an electronic data collection system and implications for future international, multi-centre cohort studies

OBJECTIVES

The aim was to assess whether the Knee Society Score, Oxford Knee Score (OKS) and Knee Injury and Osteoarthritis Outcome Score (KOOS) were comparable in asymptomatic, healthy, individuals of different age, gender and ethnicity, across two remote continents. The purpose of this study was to establish normal population values for these scores using an electronic data collection system.

HYPOTHESIS

There is no difference in clinical knee scores in an asymptomatic population when comparing age, gender and ethnicity, across two remote continents.

METHODS

312 Australian and 314 Canadian citizens, aged 18-94 years, with no active knee pain, injury or pathology in the ipsilateral knee corresponding to their dominant arm, were evaluated. A knee examination was performed and participants completed an electronically administered questionnaire covering the subjective components of the knee scores. The cohorts were age- and gender-matched. Chi-square tests, Fisher's exact test and Poisson regression models were used where appropriate, to investigate the association between knee scores, age, gender, ethnicity and nationality.

RESULTS

There was a significant inverse relationship between age and all assessment tools. OKS recorded a significant difference between gender with females scoring on average 1% lower score. There was no significant difference between international cohorts when comparing all assessment tools.

CONCLUSIONS

An electronic, multi-centre data collection system can be effectively utilized to assess remote international cohorts. Differences in gender, age, ethnicity and nationality should be taken into consideration when using knee scores to compare to pathological patient scores. This study has established an electronic, normal control group for future studies using the Knee society, Oxford, and KOOS knee scores.

LEVEL OF EVIDENCE

Diagnostic Level II.

The Effect of Age, Sex, Area Deprivation, and Living Arrangements on Total Knee Replacement Outcomes: A Study Involving the United Kingdom National Joint Registry Dataset

Background:

Total knee replacement (TKR) is a common procedure for the treatment of osteoarthritis that provides a substantial reduction of knee pain and improved function in most patients. We investigated whether sociodemographic factors could explain variations in the benefit resulting from TKR.

Methods:

Data were collected from 3 sources: the National Joint Registry for England, Wales, Northern Ireland, and the Isle of Man; National Health Service (NHS) England Patient Reported Outcome Measures; and Hospital Episode Statistics. These 3 sources were linked for analysis. Pain and function of the knee were measured with use of the Oxford Knee Score (OKS). The risk factors of interest were age group, sex, deprivation, and social support. The outcomes of interest were sociodemographic differences in preoperative scores, 6-month postoperative scores, and change in scores.

Results:

Ninety-one thousand nine hundred and thirty-six adults underwent primary TKR for the treatment of osteoarthritis in an NHS England unit from 2009 to 2012. Sixty-six thousand seven hundred and sixty-nine of those patients had complete knee score data and were included in the analyses for the present study. The preoperative knee scores were worst in female patients, younger patients, and patients from deprived areas. At 6 months postoperatively, the mean knee score had improved by 15.2 points. There were small sociodemographic differences in the benefit of surgery, with greater area deprivation (−0.71 per quintile of increase in deprivation; 95% confidence interval [CI], −0.76 to −0.66; p < 0.001) and younger age group (−3.51 for ≤50 years compared with 66 to 75 years; 95% CI, −4.00 to −3.02; p < 0.001) associated with less benefit. Cumulatively, sociodemographic factors explained <1% of the total variability in improvement.

Conclusions:

Sociodemographic factors have a small influence on the benefit resulting from TKR. However, as they are associated with the clinical threshold at which the procedure is performed, they do affect the eventual outcomes of TKR.

Level of Evidence:

Prognostic Level IV. See Instructions for Authors for a complete description of evidence.

Early Clinically Relevant Improvement in Quality of Life and Clinical Outcomes 1 Year Postsurgery in Patients with Knee and Hip Joint Arthroplasties

Objective To measure and identify the determinants of the outcomes after hip/knee arthroplasty (HA/KA) in patients with osteoarthritis during the first postsurgical year. Design In this prospective observational study, we evaluated the preoperative and postoperative (3, 6, and 12 months) outcomes of 626 patients who underwent HA (346 with median age 65 years, 59% female) or KA (280 with median age 66.5 years, 54% female) between 2008 and 2013. Generic and specific tools were used to measure health-related quality of life (HRQoL) and utility. Good outcome was defined as an improvement in WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) greater than or equal to the minimal important difference (MID). Regressions were performed to evaluate the relationship between preoperative and postoperative measures and evolution of WOMAC/good outcome. Results We observed an almost systematic improvement of all parameters for up to 12 months, but especially at the 3-month follow-up. The low number of comorbidities and the absence of postoperative complications were the common determinants of improvement of WOMAC total score after 12 months. Other parameters (background of the joint, preoperative function and length of hospital stay in KA group; place of discharge in HA group) affected the evolution of WOMAC scores. 87.09% of HA and 73.06% of KA patients experienced a good outcome. A small number of comorbidities, a worse preoperative function, a shortened hospital stay (KA only), and an absence of early postoperative complications (HA only) significantly predicted a good outcome. Conclusions Intermediate HRQoL following HA or KA improved quickly from preoperative levels for all instruments. More than 70% of patients achieved a good outcome defined as improved pain, stiffness and disability and the predictors are slightly close.

The validity and reliability of the modified forgotten joint score

We aim to validate the "Modified Forgotten Joint Score" (MFJS) as a new patient-reported outcome measure (PROM) in hip and knee arthroplasty, against the UK's gold standard Oxford Hip and Knee Scores (OHS/OKS). The original Forgotten Joint Score (FJS) (12 items) was created to assess post-arthroplasty joint awareness. We modified the FJS to 10-items to improve its reliability. Postal questionnaires were sent out to 400 total hip or knee replacement (THR/TKR) patients who were 1-2 years' post-op, along with the OHS/OKS. Data, collected from the 212 returned questionnaires (53% response rate), was analysed in relation to construct and content validity. A sub-cohort of 77 patients took part in a test-retest repeatability study, to assess reliability of the MFJS. The MFJS proved to have an increased discriminatory power in high-performing patients in comparison to the OHS and OKS. 30.8% of TKR patients (n = 131) scored highly (87.5% or more) in the OKS compared to just 7.69% in the MFJS TKR patients. The MFJS proved to have increased test-retest repeatability, based upon its intra-class correlation coefficient of 0.968 compared to the Oxford's 0.845, p < 0.001. The MFJS is a more relevant tool, compared to the FJS, with greater discrimination in the assessment of well performing hip and knee arthroplasties in comparison to the OHS/OKS.

A lateral retinacular release during total knee arthroplasty changes femorotibial kinematics: an in vitro study

INTRODUCTION

Lateral retinacular release (LRR) is a common procedure during total knee arthroplasty (TKA), especially if patellar maltracking is observed intraoperatively. The impact of LRR on patellofemoral kinematics is well-examined, but the influence on femorotibial kinematics requires more elucidation. Therefore, the aim of this study was to evaluate the effects of LRR on femorotibial kinematics in vitro.

MATERIALS AND METHODS

A fixed bearing TKA was implanted in six human knee specimens. Femorotibial kinematics were measured dynamically through the use of a custom-constructed knee rig which flexes the knee from 20° to 120° under weight bearing conditions. Measurements were performed before and after LRR. LRR was performed completely including transection of synovium, retinaculum and tractus fibers. For the registration of tibiofemoral kinematics a 3-dimensional-ultrasound-based motion analysis system was used.

RESULTS

LRR revealed a significant reduction of femoral rollback at the lateral compartment (9.4 ± 5.0 vs 7.8 ± 9.4 mm; p < 0.01), whereas the present decrease of femoral rollback at the medial compartment was not significant (3.4 ± 4.7 vs 2.3 ± 5.9 mm; p = 0.34). Accordingly, LRR significantly reduced internal rotation of the tibia (0.8°; p < 0.01).

CONCLUSION

The results suggest that LRR significantly decreases lateral femoral rollback as well as internal rotation of the tibia, probably by changing the tension of the iliotibial band. When performing a LRR in clinical routine, surgeons should be aware of altering not only patellofemoral kinematics but also the femorotibial kinematics.

John Charnley Award: Randomized Clinical Trial of Direct Anterior and Miniposterior Approach THA: Which Provides Better Functional Recovery?

BACKGROUND

The choice of surgical approach for THA remains controversial. Some studies suggest that the direct anterior approach (DAA) leads to less muscle damage than the miniposterior approach (MPA), but there is little high-quality evidence indicating whether this accelerates recovery, or whether this approach-which may be technically more demanding-is associated with component malposition or more complications.

QUESTIONS/PURPOSES

(1) Does the DAA result in faster return to activities of daily living than the MPA? (2) Does the DAA have superior patient-reported outcome measures than the MPA? (3) Does the DAA result in improved radiographic outcomes than the MPA? (4) Does the DAA have a higher risk of complications than the MPA?

METHODS

Between March 1, 2013, and May 31, 2016, 116 patients undergoing primary unilateral THA were randomized to either the DAA or MPA; 15 patients withdrew after randomization, and one died 6 months after surgery from a stroke unrelated to the procedure. Recruitment stopped when 52 patients had been randomized into the DAA group and 49 in the MPA group (n = 101). After patient randomization, one high-volume surgeon performed all of the DAAs and three high-volume surgeons performed the MPA THAs. The groups did not differ in age (65 years; SD 11; range, 38-86 years), sex (52% women), or body mass index (mean 29 kg/m; SD 6 kg/m; range, 21-40 kg/m; all p > 0.40). Functional results included time to discontinue gait aids, discontinue all narcotics, and independence with various activities of daily living; accelerometer data evaluated activity level. Clinical and radiographic outcomes, Hip disability and Osteoarthritis Outcome Score, SF-12, and Harris hip scores to 1 year were also tabulated. The minimum followup was 365 days (mean ± SD, 627 ± 369 days).

RESULTS

There were slight differences in early functional recovery that favored the DAA versus the MPA: time to discontinue walker use (10 versus 15 days, p = 0.01) and time to discontinue all gait aids (17 versus 24 days, p = 0.04). There were no other differences in early functional milestones, although at 2 weeks after surgery, mean steps per day were 3897 (SD 2258; range, 737-11,010) for the DAA versus 2235 for the MPA (SD 1688; range, 27-7450; p < 0.01). There was no difference in activity monitoring at 1 year. There were no differences in patient-reported outcome scores between the groups. There was no difference in the radiographic parameters measured in the two groups, including leg length discrepancy, component position, or offset, and there was no subsidence observed in any hip. There was no difference in complications between the DAA and the MPA groups (8% [four of 52] versus 10% [five of 49]; p = 0.33).

CONCLUSIONS

Both the DAA and MPA approaches provided excellent early recovery with a low risk of complications. Patients undergoing the DAA had a slightly faster recovery, as measured by milestones of function and quantified by activity monitor data, but no substantive differences were evident at 2 months. Because the DAA is the less studied approach, longer term (> 1 year) complications may yet accrue, will be important to quantify, and may offset early benefits.

LEVEL OF EVIDENCE

Level I, therapeutic study.

Ten-year survival and patient-reported outcomes of a medial unicompartmental knee arthroplasty incorporating an all-polyethylene tibial component

INTRODUCTION

Biomechanical studies have suggested that proximal tibial strain is elevated in UKAs incorporating all-polyethylene tibial components with concern that this leads to premature failure. This study reports minimum 10-year outcomes for a UKA incorporating an all-polyethylene tibial component to determine whether these concerns were realised.

MATERIALS AND METHODS

109 fixed bearing UKAs (97 patients, mean age 68 (range 48-87), 54/97 (56%) female) with all-polyethylene tibial components were followed up for ≥ 10 years with Oxford Knee Scores, Forgotten Joint Scores and Kaplan-Meier analysis. 106/109 implants were 7 mm, 3 were 9.5 mm.

RESULTS

Ten-year survival was 85.5% (78.6-92.4 95% CI) with the end-point failure for any reason. Unexplained pain was the commonest mode of failure (6/17) followed by lateral compartment osteoarthritis (5/17) and tibial subsidence/loosening (4/17). Revision rate was highest at 2-5 years due to revisions for unexplained pain. Ten-year survival was worse in patients < 65 years old (p = 0.035), in those with BMI > 30 (p = 0.017) and in those with postoperative increases in medial tibial sclerosis (p < 0.001 log-rank). Implant malalignment was not significantly associated with failure. Radioisotope bone scans in 16 patients all remained "hot" at mean 6.1 years (range 2.1-11.5). Relative risk of failure in patients < 65 years was 2.9 (1.2-7.0 95% CI) and when BMI > 30 was 2.9 (1.2-6.9 95% CI). In those with intact UKAs at 10 years, mean Oxford Knee Score was 34.8 ± 10.7, Forgotten Joint Score was 37.9 ± 26.7 and 96% were satisfied with their knee.

CONCLUSION

The high rate of early failure between 2 and 5 years in this all-polyethylene tibial component UKA did not persist in the long term. Though medial proximal tibial metabolic changes appear to persist they are not necessarily symptomatic. BMI > 30 and age < 65 years were significant risk factors for revision.

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.].

Mediolateral femoral component position in TKA significantly alters patella shift and femoral roll-back

PURPOSE

Increased retropatellar pressure and altered kinematics are associated with anterior knee pain and unsatisfied patients after total knee arthroplasty (TKA). Since malposition of the implant is believed to contribute to postoperative pain, we performed this in vitro study to evaluate the influence of mediolateral femoral component position on retropatellar pressure as well as tibio-femoral and patella kinematics.

METHODS

For the test, a fixed-bearing TKA was implanted in eight fresh frozen cadaver specimens. To determine the impact of mediolateral (ML) position, three variants of femoral components (3-mm medialization, neutral position and 3-mm lateralization) were produced using rapid prototyping replicas. In a knee rig, a loaded squat from 20° to 120° of flexion was applied. Retropatellar pressure distribution was measured with a pressure-sensitive film. Additionally, an ultrasonic-based three-dimensional motion analysis system was used to register patello- and tibio-femoral kinematics.

RESULTS

ML translation of the femoral component by 3 mm did not lead to a significant alteration in retropatellar peak pressure (medial 6.5 ± 2.5 MPa vs. lateral 6.0 ± 2.4 MPa). Following the ML translation of the femoral component, the patella was significantly shifted and tilted in the same directions. Varying the ML femoral component position also led to a significant alteration in femoral roll-back.

CONCLUSION

In day-by-day use, ML position should be chosen with care since there is a significant influence on patella shift and femoral roll-back. Retropatellar pressure is not significantly altered, so there is no clear evidence of an impact on anterior knee pain.

Measuring everyday functional competence using the Rasch assessment of everyday activity limitations (REAL) item bank

OBJECTIVE

Traditional patient-reported physical function instruments often poorly differentiate patients with mild-to-moderate disability. We describe the development and psychometric evaluation of a generic item bank for measuring everyday activity limitations in outpatient populations.

STUDY DESIGN AND SETTING

Seventy-two items generated from patient interviews and mapped to the International Classification of Functioning, Disability and Health (ICF) domestic life chapter were administered to 1128 adults representative of the Dutch population. The partial credit model was fitted to the item responses and evaluated with respect to its assumptions, model fit, and differential item functioning (DIF). Measurement performance of a computerized adaptive testing (CAT) algorithm was compared with the SF-36 physical functioning scale (PF-10).

RESULTS

A final bank of 41 items was developed. All items demonstrated acceptable fit to the partial credit model and measurement invariance across age, sex, and educational level. Five- and ten-item CAT simulations were shown to have high measurement precision, which exceeded that of SF-36 physical functioning scale across the physical function continuum. Floor effects were absent for a 10-item empirical CAT simulation, and ceiling effects were low (13.5%) compared with SF-36 physical functioning (38.1%). CAT also discriminated better than SF-36 physical functioning between age groups, number of chronic conditions, and respondents with or without rheumatic conditions.

CONCLUSION

The Rasch assessment of everyday activity limitations (REAL) item bank will hopefully prove a useful instrument for assessing everyday activity limitations. T-scores obtained using derived measures can be used to benchmark physical function outcomes against the general Dutch adult population.

Early Spatiotemporal Patterns and Knee Kinematics during Level Walking in Individuals following Total Knee Arthroplasty

Purpose

With the aim of investigating the spatiotemporal features of early gait pattern and knee kinematics after total knee arthroplasty and analyzing the association between outcomes of gait analyses and knee kinematic parameters, the relationship between walking and dynamic knee deformity at the early period after total knee arthroplasty was assessed in this study.

Methods

Eighteen patients including 14 women and 4 men who underwent total knee arthroplasty were analyzed using three-dimensional gait analysis system to observe gait parameters and values of maximum knee flexion angle (MKFA) during swing phase and knee flexion angle (KFA) and knee valgus angle (KVA) at midstance phase.

Results

3D gait analysis showed that operated side exhibited significantly less total support time and single support time as well as significantly longer swing phase compared with the other side. During walking, the operated side had significantly smaller MKFA and greater KFA and KVA than the nonoperated side. There was moderate to significant correlation between gait pattern and the dynamic knee kinematics.

Conclusion

The gait abnormality of patients after TKA was associated with inadequate flexion of knees at swing phase and insufficient extension at stance phase as well as increased range of valgus.

Influence of mediolateral tibial baseplate position in TKA on knee kinematics and retropatellar pressure

PURPOSE

Anterior knee pain is a major reason for unsatisfied patients after total knee arthroplasty (TKA). Since malposition and increased retropatellar peak pressure are supposed to contribute to pain, we conducted this in vitro study to analyse the influence of mediolateral tibial component position on tibiofemoral and patella kinematics as well as retropatellar pressure.

METHODS

Eight fresh frozen cadaver specimens were tested after a fixed-bearing TKA. To evaluate the influence of mediolateral tibial component position, special inlays with 3 mm of medialization and lateralization were constructed. For the analysis, a weight-bearing knee rig under a loaded squat from 20° to 120° of flexion was used. Tibiofemoral and patella kinematics were measured with an ultrasonic-based three-dimensional motion analysis system. Additionally, retropatellar pressure distribution was registered with a pressure-sensitive film.

RESULTS

Alteration of mediolateral tibial component position by 3 mm did not reveal a significant influence on retropatellar peak pressure (7.5 ± 2.5 vs. 7.2 ± 2.6 MPa). Regarding tibiofemoral kinematics, 3-mm medialization of the tibial baseplate significantly increased lateral femoral rollback and femorotibial external rotation. Medialization of 3 mm also significantly increased the relative medial patella shift and decreased lateral patella tilt.

DISCUSSION

Medialization of the tibial baseplate came along with more lateral rollback and external femorotibial rotation. For the positioning of the tibial baseplate, rotational alignment seems to be more important than mediolateral orientation. Since retropatellar peak pressure remained rather unchanged, the tibial baseplate should be placed by the surgeon looking for a maximal tibial coverage without overhang.

Normal population reference values for the Oxford and Harris Hip Scores - electronic data collection and its implications for clinical practice

BACKGROUND

The aim of this study was to assess whether the Harris Hip Score (HHS) and the Oxford Hip Score (OHS) were comparable in normal, healthy, pathology-free individuals of different age, gender, ethnicity, handedness and nationality. The purpose of this study was to establish normal population values for the HHS and OHS using an electronic data collection system.

METHODS

317 Australian and 310 Canadian citizens with no active hip pain, injury or pathology in the ipsilateral hip corresponding to their dominant arm, were evaluated. Participants completed an electronically-administered questionnaire and were assessed clinically. Chi-square tests, Fisher's exact test and Poisson regression models were used where appropriate, to investigate the association between hip scores, ethnicity, nationality, gender, handedness and age.

RESULTS

There was a statistically significant association between the OHS and age (p<0.0001) and the HHS and age (p = 0.0006); demonstrating that as age increased, normal hip scores decreased. There was no statistically significant association between the HHS and gender (p = 0.1389); or HSS and nationality, adjusting for age (p = 0.5698) and adjusting for gender (p = 0.6997). There was no statistically significant association between the OHS and gender (p = 0.1350). Australians reported a statistically significant 4.2% higher overall OHS value compared to Canadians (p = 0.0490). There was no statistically significant association between the OHS and nationality in age groups 18-79 years. Participants >80 years reported a statistically significant association between the OHS and nationality (p<0.0001).

CONCLUSIONS

Studies using an electronic control group should consider differences in gender, age, ethnicity and nationality when using the HHS and OHS to assess patient outcomes. This study has established an electronic, normal control group for studies using the HHS and OHS. When using the OHS, the control group should be sourced from the same country of origin. When using the HHS, the control group should be sourced from a pre-established control group within a database, without necessarily being sourced from the same country of origin.

A Systematic Review of Measurement Properties of Patient-Reported Outcome Measures Used in Patients Undergoing Total Knee Arthroplasty

BACKGROUND

While clinical research on total knee arthroplasty (TKA) outcomes is prevalent in the literature, studies often have poor methodological and reporting quality. A high-quality patient-reported outcome instrument is reliable, valid, and responsive. Many studies evaluate these properties, but none have done so with a systematic and accepted method. The objectives of this study were to identify patient-reported outcome measures (PROMs) for TKA, and to critically appraise, compare, and summarize their psychometric properties using accepted methods.

METHODS

MEDLINE, EMBASE, SCOPUS, Web of Science, PsycINFO, and SPORTDiscus were systematically searched for articles with the following inclusion criteria: publication before December 2014, English language, non-generic PRO, and evaluation in the TKA population. Methodological quality and evidence of psychometric properties were assessed with the COnsensus-based standards for the selection of health Status Measurement INstruments (COSMIN) checklist and criteria for psychometric evidence proposed by the COSMIN group and Terwee et al.

RESULTS

One-hundred fifteen studies on 32 PROMs were included in this review. Only the Work, Osteoarthritis or joint-Replacement Questionnaire, the Oxford Knee Score, and the Western Ontario and McMaster Universities Arthritis Index had 4 or more properties with positive evidence.

CONCLUSION

Most TKA PROMs have limited evidence for their psychometric properties. Although not all the properties were studied, the Work, Osteoarthritis or joint-Replacement Questionnaire, with the highest overall ratings, could be a useful PROM for evaluating patients undergoing TKA. The methods and reporting of this literature can improve by following accepted guidelines.

Physical Function and Physical Activity in Obese Adults After Total Knee Arthroplasty

Obese patients are more likely to have osteoarthritis and total knee arthroplasty (TKA). This investigation sought to evaluate physical function, activity level, and quality of life (QOL). Obese participants near 1-year postsurgical follow-up appointment were recruited. Evaluation included QOL and activity questionnaire, medical histories, anthropometrics, strength, and aerobic capacity. Sixty participants completed assessments. Obese TKA patients have physical performance limitations and low physical activity levels 1 year after surgery and completion of postoperative rehabilitation.

Age, Sex, Body Mass Index, Education, and Social Support Influence Functional Results After Total Knee Arthroplasty

Introduction:

Total knee arthroplasty (TKA) is an effective treatment for knee osteoarthritis. Patient-reported outcome after TKA is influenced by multiple patient-related factors. The aim of this study was to prospectively evaluate preoperative patient-related factors and to compare the self-reported outcomes 1 year after TKA among groups differing by age, sex, body mass index (BMI), education, and social support level.

Methods:

314 patients, who underwent TKA in Vilnius Republican University Hospital between the end of 2012 and the middle of 2014, were included in a study. The preoperative and 12-month follow-up measurements were obtained using Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Short Form-12 (SF-12). Differences between patient groups according to gender, age, BMI, level of education, and level of social support were analyzed.

Results:

At 12-month follow-up men demonstrated better results than women in WOMAC (P = .003) and SF-12 both domains (P < .05). Patients with a higher social support demonstrated higher scores in physical function according to SF-12 (P = .008). Better preoperative WOMAC and SF-12 scores were a predictor of better outcome 1 year after surgery. There was no difference in postoperative scores in different age, BMI, and education groups according to WOMAC and SF-12.

Conclusion:

There is no difference in self-reported functional outcome between patient groups differing in age, BMI, and education. Men and socially supported patients demonstrate better postoperative functional results 12 months after TKA. Better preoperative knee function and overall physical and mental function are predictors of better outcome 1 year after TKA. Age and obesity should not be limiting factors when considering who should receive this surgery.

High correlation of the Oxford Knee Score with postoperative pain, but not with performance-based functioning

PURPOSE

The Oxford Knee Score (OKS) is a widely known patient-related outcome measure (PROM) to determine pain and knee functioning before and after total knee arthroplasty (TKA). Self-reported function is mainly influenced by change in pain; therefore, it was hypothesized that the OKS correlates more with pain than with performance-based functioning.

METHODS

In a prospective cohort of 88 patients, who had a cementless mobile-bearing TKA, included in a randomized clinical trial, the correlation between the overall OKS, and its subscales for pain (PCS) and function (FCS), with performance-based functioning using the DynaPort^® Knee Score (DKS), visual analogue scale score for pain (VAS) and the Knee Society Score (KSS) was evaluated. All scores were measured preoperatively, 6 months and 1 year after surgery. Overall change in outcome over time was analysed until 5 years after surgery.

RESULTS

All scores improved over time. The DKS was influenced by sex, preoperative BMI and age. The internal consistency of the OKS PCS increased over time, whereas the OKS FCS remained the same. The mean postoperative OKS FCS showed moderate correlation with the DKS (r = 0.65, p < 0.001), and the mean postoperative OKS and OKS PCS showed high correlation with the VAS (r = -0.79 and r = -0.82, respectively, p < 0.001). The mean postoperative KSS showed high correlations with the OKS (r = 0.80, p < 0.001), the OKS PCS (r = 0.72 p < 0.001) and OKS FCS (r = 0.74, p < 0.001).

CONCLUSION

The postoperative OKS and the OKS PCS showed high correlation with pain, but only the postoperative OKS FCS was well correlated with performance-based functioning. This suggests that the OKS is more related to pain and tells us less on postoperative functioning. This is important when the OKS as PROM is used to evaluate the quality of orthopaedic care of patients with TKA.

LEVEL OF EVIDENCE

III.