What is the best way of assessing outcome after total knee replacement?

The short- and long-term effects of a fall prevention program on the frequency of falls following total knee replacement: A pragmatic single-blinded randomized controlled trial protocol

BACKGROUND

Falling following total knee replacement (TKR) is a significant issue, and can result in serious fatal and non-fatal injuries. The proposed study aims to investigate the short and long-term effects of integrating a falls prevention program into conventional physiotherapy versus just conventional physiotherapy on the number of falls, and any subsequent effects on balance, and functional ability among TKR patients.

METHODS AND DESIGN

This is a parallel group prospective (52 weeks) randomized single-blinded pragmatic controlled trial conducted at Alrazi Orthopedic Hospital, in Kuwait. Sample size will be 90 pariticpants (45 participants in each group). Particpants will be randomized to intervention or control group. Outcome measures will be collected at baseline, 12 weeks and 52 weeks by investigators who are blinded to treatment allocation. Primary outcome will be fall rate assessed at 52 weeks following the TKR surgery. Secondary outcomes will include knee range of motion, severity of pain, 10-m walk test, Timed Up and Go test, Berg Balance Scale, 30-s sit to stand, patient adherence to home program and patient's satisfaction. Two-way multivariate ANOVA (group × time) will be performed to assess the group (experimental and control group) differences over time (baseline, 12, and 52 weeks).

DISCUSSION

Investigating the physiotherapy programs that could minimize or prevent the risk of falling among TKR patients seems important. The proposed study will be the first step toward determining the exercise program that could be effective in reducing the number of falls among TKR patients.

TRIAL REGISTRATION

ClinicalTrials.gov, Identifier NCT05642260.

Randomized Placebo-Controlled Trial of 60-Day Percutaneous Peripheral Nerve Stimulation Treatment Indicates Relief of Persistent Postoperative Pain, and Improved Function After Knee Replacement

OBJECTIVES

Total knee arthroplasty (TKA) is an effective surgery for end-stage knee osteoarthritis, but chronic postoperative pain and reduced function affect up to 20% of patients who undergo such surgery. There are limited treatment options, but percutaneous peripheral nerve stimulation (PNS) is a promising nonopioid treatment option for chronic, persistent postoperative pain. The objective of the present study was to evaluate the effect of a 60-day percutaneous PNS treatment in a multicenter, randomized, double-blind, placebo-controlled trial for treating persistent postoperative pain after TKA.

MATERIALS AND METHODS

Patients with postoperative pain after knee replacement were screened for this postmarket, institutional review board-approved, prospectively registered (NCT04341948) trial. Subjects were randomized to receive either active PNS or placebo (sham) stimulation. Subjects and a designated evaluator were blinded to group assignments. Subjects in both groups underwent ultrasound-guided placement of percutaneous fine-wire coiled leads targeting the femoral and sciatic nerves on the leg with postoperative pain. Leads were indwelling for eight weeks, and the primary efficacy outcome compared the proportion of subjects in each group reporting ≥50% reduction in average pain relative to baseline during weeks five to eight. Functional outcomes (6-minute walk test; 6MWT and Western Ontario and McMaster Universities Osteoarthritis Index) and quality of life (Patient Global Impression of Change) also were evaluated at end of treatment (EOT).

RESULTS

A greater proportion of subjects in the PNS groups (60%; 12/20) than in the placebo (sham) group (24%; 5/21) responded with ≥50% pain relief relative to baseline (p = 0.028) during the primary endpoint (weeks 5-8). Subjects in the PNS group also walked a significantly greater distance at EOT than did those in the placebo (sham) group (6MWT; +47% vs -9% change from baseline; p = 0.048, n = 18 vs n = 20 completed the test, respectively). Prospective follow-up to 12 months is ongoing.

CONCLUSIONS

This study provides evidence that percutaneous PNS decreases persistent pain, which leads to improved functional outcomes after TKA at EOT.

A comparative intervention trial of deer milk and an oral nutritional supplement efficacy for improving older adults' nutritional status, muscle mass and physical performance

OBJECTIVES

To compare the effectiveness of deer milk (DM) for improving nutritional status, muscle mass and physical performance with that of a commercially available oral nutritional supplement (ONS) in older women.

METHODS

This study was an 11-week randomised, double-blind, parallel group study. Healthy women (N = 120) aged 65-80 years, the majority having a body mass index (BMI) < 25 kg/m2 were recruited. The women were randomly assigned to either 200 ml DM or a commercial ONS for 11 weeks. Data on habitual macronutrient intake, nutritional status (Mini Nutrition Assessment-Short Form, MNA-SF; ≤7 malnourished, 8-11 at risk of malnutrition, ≥12 normal nutrition), anthropometrics/body composition, and physical performance were collected. Blood samples were collected for metabolic markers.

RESULTS

102 women (DM 45, ONS 57) completed the study, of whom 29% had a dietary protein intake of <1 g/kg body weight per day, and 38% at risk of malnutrition. There were no between group differences in percentage change in MNA-SF score and body composition (P > 0.05), but a trend for a difference in handgrip strength (DM 11.7 ± 49.8% vs. ONS -2.42 ± 17.9%, P = 0.06). Further exploratory analysis showed that there was a trend for a between group difference in percentage change in MNA-SF score, favoring DM (DM 7.72 + 13.0% vs. ONS 0.63 + 9.25%, P = 0.06) only in women at risk of malnutrition. There was also a between group difference in percentage change in muscle mass (DM 1.68 ± 2.77% vs. ONS -0.18 ± 2.81%, P = 0.02) in women with BMI ≥25 kg/m2 and in handgrip strength (DM 10.6 ± 23.6% vs. ONS -5.03 ± 18.1%, P < 0.01) in women with BMI<25 kg/m2. Total cholesterol, LDL and LDL:HDL ratio did not change over time (P > 0.05), but there was a between group difference in percentage change in these markers (total cholesterol: DM 3.01 ± 6.97% vs. ONS -2.65 ± 9.92%, P < 0.01; LDL: DM 4.22 ± 14.9% vs. ONS -6.05 ± 17.6%, P < 0.01; LDL:HDL ratio: DM: 2.27 ± 16.4% vs. ONS: -5.78 ± 18.2%, P = 0.02).

CONCLUSION

Baseline nutritional status and BMI may modulate nutritional status, muscle mass and physical performance response to DM (as compared with ONS), suggesting DM may improve nutritional status and physical performance in women at risk of malnutrition and/or with lower BMI, and improve muscle mass in women with a higher BMI. The study was registered with the Australian New Zealand Clinical Trial Registry ACTRN12621000650897p.

Patient Acceptable Symptom State for the Forgotten Joint Score in Primary Total Knee Arthroplasty

BACKGROUND

In order to better understand the clinical benefits of total knee arthroplasty (TKA) and improve the interpretability of the Forgotten Joint Score (FJS-12), the establishment of a meaningful change in score is necessary. The purpose of this study is to determine the threshold of the FJS-12 for detecting the patient acceptable symptom state (PASS) following primary TKA.

METHODS

We retrospectively reviewed all patients who underwent elective, primary TKA and answered both the FJS-12 and the Knee Injury Osteoarthritis Outcome Survey, Joint Replacement KOOS, JR surveys 1-year postoperatively. The questionnaires were administered via a web-based electronic application. KOOS, JR score was used as the anchor. The anchor for PASS calculation should relate pain, physical function, and patient satisfaction. Two statistical methods were employed: (1) the receiver operating characteristic (ROC) curve point; (2) 75^th percentile of the cumulative percentage curve of patients who had the KOOS, JR score difference larger than the cut-off value.

RESULTS

This study included 457 patients. The mean 1-year FJS-12 score was 42.6 ± 27.8. The mean 1-year KOOS, JR score was 68.0 ± 17.2. A high positive correlation between FJS-12 and KOOS, JR was found (r = 0.72, P < .001) making the KOOS, JR a valid external anchor. The threshold score of the FJS-12 which maximized the sensitivity and specificity for detecting a PASS was 33.3 (AUC = 0.78, 95% CI [0.74, 0.83]). The cut-off value computed with the 75^th percentile approach was 77.1 (95% CI [73.9, 81.5]).

CONCLUSION

The PASS threshold for the FJS-12 was 33.3 and 77.1 at 1-year follow-up after primary TKA using the receiver operating characteristic (ROC) curve and 75^th percentile approaches, respectively. These values can be used to assess the successful achievement of a forgotten joint.

LEVEL III EVIDENCE

Retrospective Cohort Study.

A prospective randomised control trial comparing functional with mechanical axis alignment in total knee arthroplasty: study protocol for an investigator initiated trial

Background

A drive to improve functional outcomes for patients undergoing total knee arthroplasty (TKA) has led to alternative alignment being used. Functional alignment (FA) uses intraoperative soft tissue tension to determine the optimal position of the prosthesis within the patient’s soft tissue envelope. Angular limits for bone resections are followed to prevent long-term prosthesis failure. This study will use the aid of robotic assistance to plan and implement the final prosthesis position. This method has yet to be compared to the traditional mechanically aligned (MA) knee in a randomised trial.

Methods

A blinded randomised control trial with 100 patients will be undertaken via Perth Hip and Knee Clinic. Fifty patients will undergo a MA TKA and fifty will undergo a FA TKA. Both alignment techniques will be balanced via computer-assisted navigation to assess prosthetic gaps, being achieved via the initial bony resection and further soft tissue releases as required to achieve satisfactory balance. The primary outcome will be the Forgotten Joint Score (FJS) 2 years after surgery, with secondary outcomes being other patient-reported outcome measures, clinical functional assessment, radiographic position and complications. Other data that will be collected will be patient demography (sex, age, level of activity) and medical information (grade of knee injury, any other relevant medical information). The linear statistical model will be fitted to the response (FJS), including all the other variables as covariates.

Discussion

Many surgeons are utilising alternative alignment techniques with a goal of achieving better functional outcomes for their patients. Currently, MA TKA remains the gold standard with good outcomes and excellent longevity. There is no published RCTs comparing FA to MA yet and only two registered studies are planned or currently in progress. This study utilises a FA technique which differs from the two studies. This study will help determine if FA TKA has superior functional results for patients.

Trial registration

This trial has been registered with the Australian New Zealand Clinical Trials Registry (ANZCTR) http://www.anzctr.org.au: U1111-1257-2291, registered 25th Jan 2021. It is also listed on www.clinicaltrials.gov: NCT04748510.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05433-z.

The effect of aerobic exercise training on postmenopausal patients with knee osteoarthritis

BACKGROUND

Knee osteoarthritis (OA) is a common musculoskeletal problem encountered in the postmenopausal period.

OBJECTIVE

This study aimed to determine the impact of aerobic exercise on functional limitation, exercise tolerance, and performance tests in postmenopausal women with knee OA.

METHODS

A total of 50 women (aged between 48-78) with grade 2-3 knee OA according to the Kellgren-Lawrence radiographic scale were enrolled. OA-specific physical performance tests (40 m Fast-Paced Walk Test (40mFPWT), 30 s Chair Stand Test (30sCST), Stair Climb Test (9-step SCT)), six-minute walk test (6MWT), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Visual Analogue Scale (VAS) were performed. Fifty patients were randomized to either the treatment or control groups. The treatment group received an additional aerobic exercise training along with a combined physiotherapy program for six weeks. The aerobic exercise program was carried out by the same physiotherapist every weekday (five days) for six weeks. The control group only received a combined physiotherapy program for six weeks.

RESULTS

The post-treatment comparisons of the two groups yielded similar SCT results (p> 0.05), while VAS scores, the results of all performance tests, WOMAC scores, and the distance covered in 6MWT were significantly higher in the treatment group (p< 0.05).

CONCLUSIONS

Consequently, this study provides an insight into the efficacy of the aerobic exercise program applied along with a combined physiotherapy program in postmenopausal women with knee OA.

Long-Term Comparison Study of Patella Resurfacing Versus Non-resurfacing in Total Knee Arthroplasty with Minimum 10-Year Follow-Up

BACKGROUND

Management of the patella during total knee arthroplasty is a matter of constant debate. Numerous studies have assessed and compared the mechanical and clinical results of total knee arthroplasty with native as well as resurfaced patellae. However, the consensus has not been reached yet on this subject. This study aims to compare the outcome between patella resurfaced (PR) and non-resurfaced patellae (NPR) after a follow-up of minimum 10 years following total knee arthroplasty.

MATERIALS AND METHODS

This is a retrospective study including 63 subjects (103 knees) who had undergone total knee arthroplasty with a follow-up of 10-14 years. In this study, we evaluated the knees implanted with either press fit condylar (PFC) sigma (Depuy, Johnson & Johnson) or Nexgen (CR flex/LPS flex) (Zimmer, Warsaw, Indiana, USA) implants. Whether to perform patella resurfacing or not and choice of implants as well as implant design (posterior stabilized/cruciate retaining) was surgeons' preference. At final follow-up, clinical and functional outcome was assessed using Knee Society Scores (KSS), and comparison of difference between pre-op scores and scores at final follow-up among resurfaced versus non-resurfaced patellae groups was carried out. Patello-femoral function was assessed at final follow-up using Feller's score and the results were compared between resurfaced and non-resurfaced patellae.

RESULTS

The mean follow-up was 140 months (range 124-168 months). There were 62 knees with their patella resurfaced and 41 knees with non-resurfaced patellae There was no significant difference in the mean pre-op Knee Society Scores between PR (46.29 ± 5.17) and NPR (47.34 ± 5.95), p value 0.34. Similarly there was no significant difference in their pre-op functional score as well PR (38.53 ± 5.14) and NPR (39.22 ± 6.79), p value 0.56. Both groups had significantly improved post-operative Knee Society Scores PR (85.95 ± 5.23) and NPR (84.65 ± 5.30). However, there is no difference between these groups, p value 0.22. Functional scores also maintained significant improvement at final follow-up. Between the two groups, the resurfaced group showed a significantly higher functional score at final follow-up: PR (70.90 ± 7.73) and NPR (66.44 ± 7.12), p value 0.02. Feller's score at final follow-up for PR group was (23.36) and NPR group was (21.98), p value 0.001, which showed clear superiority of PR over NPR.

CONCLUSION

After a minimum follow-up of 10 years, there were no differences in clinical results; however, the knee function score and patello-femoral function scoring was found to be significantly higher with patella resurfacing and it was persistent across all the subgroups we had included in the study-posterior stabilized/cruciate retaining or between implants made by two different manufacturers.

Influence of early mobilization program on pain, self-reported and performance based functional measures following total knee replacement

BACKGROUND

Total knee replacement (TKR) is an optimal treatment for persons with severe knee joint pain and disability, who were unsuccessful with conservative management. Early mobilization can be defined as moving out of bed and/or walking quickly after the surgery for reducing the risks allied with bed rest. There is a paucity of studies on effects of early mobilization on a performance-based measure of timed up and go test (TUG), six-minute walk test (SMWT) and a self-reported disease-specific measure of a knee injury and Osteoarthritis outcome score (KOOS) following TKR.

METHODS

A prospective pre-post-trial was conducted at Manipal Hospital, Bangalore, India. Participants underwent early (POD '0') mobilization on the same postoperative day within 7 h post-TKR surgery. Outcome measures were recorded by an independent blinded observer. The statistical significance level was set at 'p' value < 0.05. The difference between pre-operative and post-operative outcome measure at 1 month and 3 months post-intervention were analyzed using repeated measures of ANOVA.

RESULTS

The study included a total of 78 participants (59 Females; 19 Males) and the mean age of the included participants was 64.1 ± 7 years. Amongst, 78 participants, 53 underwent unilateral TKR, 25 underwent bilateral TKR. There were three dropouts in the study due to post-operative complications. Significant improvements from pre-operative to one month were observed following POD '0' mobilization on NPRS (7.35 ± 1.2 to 4.3 ± 1.7), SMWT (169 ± 70 to 236.7 ± 80.7). KOOS subscales of pain, symptom, and quality of life showed significant changes at one month and 3 months. TUG, Knee strength, Knee ROM and KOOS ADL subscale shown improvements only at 3 months post-intervention.

CONCLUSION

Our study findings suggest that POD '0' (early) mobilization can result in reduced pain and an increase in walking speed at 1 month. Significant changes were observed in pain, Knee strength, Knee ROM, TUG, SMWT and KOOS subscales at 3 months following total knee replacement.

What is the Responsiveness and Respondent Burden of the New Knee Society Score?

BACKGROUND

Although the new Knee Society score (NKSS) has been validated by a task force, a longitudinal study of the same cohort of patients to evaluate the score's responsiveness and respondent burden has not been reported, to our knowledge.

QUESTIONS/PURPOSES

We analyzed the NKSS for (1) responsiveness; (2) respondent burden; and (3) convergent validity in 148 patients studied longitudinally during more than 1 year.

METHODS

During an 8-month period, 165 patients underwent TKA by the same surgeon at our institution, of whom 148 (90%) completed this study; the others were excluded because of distance to travel or loss to followup at the specified time. The NKSS, WOMAC, and SF-12 were completed by each patient 1 day before surgery and at 3 and 12 months postoperatively. At the same times, the original KSS (OKSS) which is designed as an observer's assessment, was completed by the same orthopaedic fellow for all patients. Responsiveness of the NKSS was assessed by determining effect size, standardized response mean (SRM), and ceiling and floor effects. Respondent burden was assessed through time to completion recorded in minutes and ease of completion which was measured objectively on a Likert scale of 1 to 5 by the patients. Convergent validity was assessed by correlating the NKSS with the WOMAC, SF-12, and OKSS (current, widely used scales) by Pearson's correlation coefficient.

RESULTS

Effect size was largest (2.83 and 3.38) and SRM was highest (2.29 and 2.68) for the NKSS at 3 and 12 months respectively, indicating the NKSS to be the most-responsive score followed by the OKSS, WOMAC, and SF-12. The NKSS exhibited no ceiling and floor effects. The NKSS took a longer time to complete (5.49 ± 3.56 minutes) compared with the WOMAC (4.64 ± 3.19 minutes) and SF-12 (4.35 ± 3.27 minutes). The mean difference in time taken for the NKSS versus the WOMAC was 0.85 minutes (95% CI, 0.54-1.17 minutes; p < 0.001) and the mean difference for the NKSS versus the SF-12 was 1.14 minutes (95% CI, 0.76-1.15 minutes; p < 0.001). Its ease of completion generally was comparable to that of the WOMAC and SF-12. Convergent validity showed a strong correlation (r > 0.6; p < 0.001) of the NKSS with the WOMAC at all times and moderate to strong correlation (r = 0.4-0.6; p < 0.001) with the SF-12 and OKSS at the first two assessments, which became strong (r > 0.6; p < 0.001) at 12 months.

CONCLUSIONS

The NKSS exhibited greater responsiveness than the WOMAC, SF-12, and OKSS scales and showed no ceiling effect, indicating adequate potential for recording future improvement. The NKSS also showed reliable convergent validity when correlated with these other scores. However, it posed a greater respondent burden in terms of time to completion.

CLINICAL RELEVANCE

As independent nondevelopers of the NKSS, we found it to be a responsive tool for assessment of TKA outcomes. We have confirmed that the NKSS can be used interchangeably for this purpose with the WOMAC scale and that it correlates positively with other established scales of the SF-12 and OKSS. Further study of the short-form version will establish whether it also can be used effectively while reducing the respondent burden.

Relationship between physical performance and self-reported function in healthy individuals across the lifespan

BACKGROUND

Functional outcome measures in clinical trials of musculoskeletal conditions need to be meaningful to individuals.

OBJECTIVES

To investigate the relationship between physical performance and self/proxy-reported function in 1000 healthy children and adults.

DESIGN

Cross-sectional observational study (1000 Norms Project).

METHODS

One thousand males and females aged 3-101 years, healthy by self-report and without major physical disability, were recruited. Twelve performance-based tests were analysed: vertical and long jump, two hand dexterity tests, four balance tests, stepping reaction time, 30-second chair stand, timed up-and-down stairs, and six-minute walk. Self/proxy-reported function was assessed using the Infant-Toddler Quality of Life questionnaire, Child Health Questionnaire, Assessment of Quality of Life (AQoL)-6D Adolescent, AQoL-8D, International Physical Activity Questionnaire and work ability question. Bivariate and multivariate correlational analyses were constructed for infants (3-4y), children (5-10y), adolescents (11-17y), adults (18-59y) and older adults (60+).

RESULTS/FINDINGS

Socio-demographic characteristics were similar to the Australian population. Among infants/children, greater jump and sit-to-stand performance correlated with higher proxy-reported function (p < 0.05). There were no significant relationships observed for adolescents (p > 0.05). Greater jump, dexterity, balance, reaction time, sit-to-stand, stair-climbing and six-minute walk performance correlated with higher self-reported function in adults (r = -0.097 to.231; p < 0.05) and older adults (r = -0.135 to 0.625; p < 0.05). Multivariate regression modelling revealed a collection of independent performance measures explaining up to 46% of the variance in self/proxy-reported function.

CONCLUSIONS

Many performance-based tests were significantly associated with self/proxy-reported function. We have identified a set of physical measures which could form the basis of age-appropriate functional scales for clinical trials of musculoskeletal conditions.

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.

Hip Abductor Strengthening Improves Physical Function Following Total Knee Replacement: One-Year Follow-Up of a Randomized Pilot Study

BACKGROUND

Total knee replacement (TKR) is the commonest surgical procedure for patients with severe pain and impaired physical function following end stage knee osteoarthritis. The hip abductors are well renowned in stabilization of the trunk and hip during walking, maintaining the lower limb position, and transferring the forces from the lower limbs to the pelvis.

OBJECTIVE

To assess the efficacy of hip abductor strengthening exercise on functional outcome using performance based outcome measures following total knee replacement.

METHODS

An observer blinded randomized pilot trial design was conducted at Manipal hospital, Bangalore, India. Participants designated for elective TKR were randomized to experimental group hip abductor strengthening along with standard rehabilitation (n=10) or control group standard rehabilitation alone (n=10). Participants followed for one year to assess physical function using performance based outcomes, such as timed up and go test, single leg stance test, six minute walk test, knee extensor strength and hip abductor strength.

RESULT

Eighteen participants with a mean age of 63.1 ± 5.5 years (8 Males and 10 Females) completed the study. Improvement in hip abduction strength, single leg stand test was superior in hip abductor strengthening group at 3 months and 1 year when compared to standard rehabilitation alone.

CONCLUSION

Hip abductor strengthening showed superior improvements in single leg stance test and six minute walk test. Hip abductor strengthening exercises has the potential to improve physical function following total knee replacement.

How often is the office visit needed? Predicting total knee arthroplasty revision risk using pain/function scores

BACKGROUND

Most patients have favorable outcomes after primary total knee arthroplasty (TKA). Well-validated methods to predict the risk of poor outcomes have not been developed or implemented. Several patients have annual clinic visits despite well-funcitoning TKA, as a routine practice, to detect early failure requiring revision surgery. It is not known whether assessment of pain and function can be used as a predictive tool for early failure and revision to guide practice. Our objective was to determine whether pain and function can predict revision after TKA.

METHODS

We retrospectively studied data from a large prospectively gathered TKA registry to examine changes in outcome scores for primary TKAs undergoing revision compared to those not requiring revision to determine the factors that are predictive for revision.

RESULTS

Of the 1,012 patients, 721 had had a single-sided primary TKA and had American Knee Society (AKS) Scores for three or more visits. 46 patients underwent revision, 23 acutely (fracture, traumatic component failure or acute infection) and 23 for latent causes (late implant loosening, progressive osteolysis, or pain and indolent infection). Mean age was 70 years for the non-revision patients, and 64 years for those revised. Both AKS Clinical and AKS Function Scores for non-revised patients were higher than in revision patients, higher in acute revision compared to latent revision patients. Significant predictors of revision surgery were preoperative, 3- and 15-month postoperative AKS Clinical Scores and 3-month AKS Function Scores. At 15-month post-TKA, a patient with a low calculated probability of revision, 32 % or less, was unlikely to require revision surgery with a negative predictive value of 99 %.

CONCLUSION

Time dependent interval evaluation post-TKA with the AKS outcome scores may provide the ability to assign risk of revision to patients at the 15-month follow-up visit. If these findings can be replicated using a patient-reported measure, a virtual follow-up with patient-reported outcomes and X-ray review may be an alternative to clinic visit for patients doing well.

Knee Injury and Osteoarthritis Outcome Score has higher responsiveness and lower ceiling effect than Knee Society Function Score after total knee arthroplasty

PURPOSE

To compare the following subjective scoring instruments: the Knee Society Function (KS-F) Score and Knee Injury and Osteoarthritis Outcome Score (KOOS) in patients who underwent total knee arthroplasty (TKA) by assessing standard metrics related to the utility of each instrument, including responsiveness, ceiling effect, and distribution of scores.

METHODS

Patients undergoing TKA for osteoarthritis (n = 82) were evaluated pre-operatively and post-operatively at a median time of 1 year (range 0.7-3.6 years) using the KS-F score and KOOS. Responsiveness, the ability of a tool to measure change over time, was evaluated by computing the standardized response mean. Ceiling effects were determined by calculating the percentage of patients who attained the best-possible score.

RESULTS

The KOOS scale had higher standardized response mean than KS-F scale in the majority of subsections (except sports and recreation). The KOOS had a lower ceiling effect in the majority of subsections (except pain) and was significantly lower on the symptoms and quality of life subscales (both p < 0.05). Scores were not normally distributed for either KS-F or KOOS scales.

CONCLUSIONS

Since the KOOS scale had a higher responsiveness and a lower ceiling effect, it appears to be a superior outcome tool versus the KS-F scale when evaluating the outcomes of TKA patients.

LEVEL OF EVIDENCE

Diagnostic Study, Level I.

Effect of rotational alignment on outcome of total knee arthroplasty

BACKGROUND AND PURPOSE

Poor outcomes have been linked to errors in rotational alignment of total knee arthroplasty components. The aims of this study were to determine the correlation between rotational alignment and outcome, to review the success of revision for malrotated total knee arthroplasty, and to determine whether evidence-based guidelines for malrotated total knee arthroplasty can be proposed.

PATIENTS AND METHODS

We conducted a systematic review including all studies reporting on both rotational alignment and functional outcome. Comparable studies were used in a correlation analysis and results of revision were analyzed separately.

RESULTS

846 studies were identified, 25 of which met the inclusion criteria. From this selection, 11 studies could be included in the correlation analysis. A medium positive correlation (ρ = 0.44, 95% CI: 0.27-0.59) and a large positive correlation (ρ = 0.68, 95% CI: 0.64-0.73) were found between external rotation of the tibial component and the femoral component, respectively, and the Knee Society score. Revision for malrotation gave positive results in all 6 studies in this field.

INTERPRETATION

Medium and large positive correlations were found between tibial and femoral component rotational alignment on the one hand and better functional outcome on the other. Revision of malrotated total knee arthroplasty may be successful. However, a clear cutoff point for revision for malrotated total knee arthroplasty components could not be identified.

A wearable mobility assessment device for total knee replacement: A longitudinal feasibility study

BACKGROUND

Total knee replacement currently lacks robust indications and objective follow-up metrics. Patients and healthcare staff are under-equipped to optimise outcomes. This study aims to investigate the feasibility of using an ear-worn motion sensor (e-AR, Imperial College London) to conduct objective, home-based mobility assessments in the peri-operative setting.

METHODS

Fourteen patients on the waiting list for knee replacement, and 15 healthy subjects, were recruited. Pre-operatively, and at 1, 3, 6, 12 and 24 weeks post-operatively, patients underwent functional mobility testing (Timed Up and Go), knee examination (including range of motion), and an activity protocol whilst wearing the e-AR sensor. Features extracted from sensor motion data were used to assess patient performance and predict patients' recovery phase.

RESULTS

Sensor-derived peri-operative mobility trends correlated with clinical measures in several activities, allowing functional recovery of individual subjects to be profiled and compared, including the detection of a complication. Sensor data features enabled classification of subjects into normal, pre-operative and 24-week post-operative groups with 89% (median) accuracy. Classification accuracy was reduced to 69% when including all time intervals.

DISCUSSION

This study demonstrates a novel, objective method of assessing peri-operative mobility, which could be used to supplement surgical decision-making and facilitate community-based follow-up.

The KSS 2011 reflects symptoms, physical activities, and radiographic grades in a Japanese population

BACKGROUND

Cultural and ethnic differences are present both in subjective and objective measures of patient health, but scoring systems do not always reflect these differences, and so validation of outcomes tools in different cultural settings is important. Recently, a revised version of The Knee Society Score® (KSS 2011) was developed, but to our knowledge, the degree that this tool evaluates clinical symptoms, physical activities, and radiographic grades in the general Japanese population is not known.

QUESTIONS/PURPOSES

We therefore asked: (1) how KSS 2011 reflects knee conditions and function in the general Japanese population, in particular evaluating changes with increasing patient age; (2) can objective measures of physical function be correlated with KSS 2011; and (3) does radiographic osteoarthritis (OA) grade correlate with KSS 2011?

METHODS

Two hundred twenty-six people in the general Japanese population, aged 35 to 92 years, with and without knee arthritis, voluntarily participated in this cross-sectional study. Residents who had no serious disease or symptoms based on a self-assessment were recruited. This study consisted of a questionnaire including self-administered KSS 2011, physical examination, and weightbearing radiographs of the knee. Leg muscle strength, Timed Up and Go test, and body mass index (BMI) were examined in all the participants. Radiographs were graded according to the Kellgren and Lawrence scale (KL grade).

RESULTS

Multivariable linear regression analysis showed that KSS 2011 correlated with age (coefficient: -0.30±0.12, p=0.011), BMI (coefficient: -1.47±0.42, p<0.001), leg muscle strength (coefficient: 0.41±0.13, p=0.002), and Timed Up and Go Test (coefficient: -1.96±0.92, p=0.034), but not sex, as independent variables by a stepwise method. KSS 2011 was also correlated with radiographic OA evaluated by KL grade (coefficient: -12.2±2.9, p<0.001).

CONCLUSIONS

KSS 2011 reflects symptoms, physical activities, and radiographic OA grades of the knee in an age-dependent manner in the general Japanese population.

LEVEL OF EVIDENCE

Level IV, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

Short-term functional versus patient-reported outcome of the bicruciate stabilized total knee arthroplasty: prospective consecutive case series

Background

The main goals of the standard treatment for advanced symptomatic knee osteoarthritis, total knee arthroplasty (TKA), are pain reduction and restoration of knee motion.

The aim of this study was to analyse the outcome of the patient-based Knee Injury and Osteoarthritis Outcome Score (KOOS), and the surgeon-based Knee Society Score (KSS) and its Knee Score (KS) and Knee Functional Score (KFS) components after (TKA) using the Journey knee prosthesis, and to assess the correlation of these scores with range of motion (ROM).

Methods

In a prospective case series study between August 1^st 2008 and May 31^st 2011, 99 patients, all operated by a single surgeon, received Journey bicruciate stabilized total knee prostheses. The female/male ratio was 53/34, the mean patient age at surgery was 68 years (range 41–83 years), and the left/right knee ratio was 55/44. The KOOS, range of motion, and KS and KFS were obtained preoperatively and at 1-year follow-up. The pre- and postoperative levels of the outcome measures were compared using the Wilcoxon signed-rank test. Correlation between ROM and patient outcomes was analysed with the Spearman coefficient.

Results

All KOOS subscores improved significantly. Ninety percent of patients improved by at least the minimum clinically relevant difference of 10 points in stiffness and other symptoms, 94.5% in pain, 94.5% in activities of daily living, 84.9% in sports and recreation, and 90% in knee-related quality of life. The mean passive and active ROM improved from 122.4° (range 90-145°) and 120.4° (range 80-145°) preoperatively to 129.4° (range 90-145°) and 127.1° (range 100-145°) postoperatively. The highest correlation coefficients for ROM and KOOS were observed for the activity and pain subscores. Very low or no correlation was seen for the sport subscore.

There was a significant and clinically relevant improvement of KSS (preop/postop 112.2/174.5 points), and its KS (preop/postop 45.6/86.8 points) and KFS (preop/postop 66.6/87.8 points) components.

Conclusions

The Journey bicruciate stabilized knee prosthesis showed good 1-year postoperative results in terms of both functional and patient-based outcome. However, higher knee ROM correlates only moderately with patient-based outcome, implying that functionality afforded by the Journey bicruciate TKA is not equivalent to patient satisfaction.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-435) contains supplementary material, which is available to authorized users.

Clinimetric quality of the new 2011 Knee Society score: high validity, low completion rate

BACKGROUND

The demands of the younger and more active current total knee arthroplasty (TKA) patients are not in line with the current outcome assessments. Therefore, new questionnaires are developed or adjusted, as with the popular 1989 Knee Society Score (KSS). This study is the first to investigate the clinimetric parameters of the patient-reported outcome measurement (PROM) part of the 2011 KSS.

METHODS

Four-hundred-fifteen primary Dutch TKA patients were scored using the PROM part of the 2011 KSS. The scale is subdivided into an Objective (not evaluated), Satisfaction, Expectation and Function subscales. Clinimetric quality was evaluated by response and completion rate, test-retest reliability (n=29, intraclass correlation coefficient), internal consistency (n=172, Cronbach's alpha), construct validity (Pearson's correlations with 1989 KSS (n=75) and KOOS-PS (n=139)) and responsiveness (n=20, paired-samples t-test, effect sizes and floor and ceiling effects).

RESULTS

A response rate of 96% and completion rate of 43% were found. Reliability and internal consistency proved excellent with ICCs≥0.79 and Cronbach's alpha≥0.76 for all subscales. Strong correlations were found between the Function subscales of the 2011 KSS and KOOS-PS (r=-0.60 to -0.83). All subscales improved significantly after intervention, with exception of Walking & Standing and Discretionary Activities. 23% reached the maximum score postoperatively in Walking & Standing, indicating a ceiling effect.

CONCLUSIONS

The 2011 KSS is a reliable, internal consistent, construct valid and responsive questionnaire to assess the outcome of the Dutch TKA patients. Optimizations (e.g. shortening the scale, simplified design) are recommended to increase the disappointing completion rate.

CLINICAL RELEVANCE

The 2011 KSS is a reliable, internal consistent, construct valid and responsive questionnaire to assess the outcome of the Dutch TKA patients.

Reliability of the "American Knee Society Score" (AKSS)

Objective

To analyze the reproducibility of the "American Knee Society Score" (AKSS) scale, and determine its measurement, in order to make it useful for the evaluation of patients with osteoarthritis or who have undergone total knee arthroplasty.

Methods

In the first interview, the AKSS was applied along with the SF-36 and WOMAC (examiner 1). After thirty minutes the same patients answered only the AKSS. After a two week break, a third additional interview with AKSS was applied (examiner 2).

Results

We selected 58 patients with a mean age of 67.4 years. In the analysis of reproducibility, by ICC, there was strong inter-examiner and intra-examiner correlation for two AKSS components. In the individual items analysis there was good correlation for "Pain", "Range of Motion", "Flexion contracture" and all items of the AKSS Function component. Validation through the Pearson coefficient showed good correlation between AKSS "Pain," WOMAC "pain" and SF-36 "Pain domain", and good correlation between the AKSS and SF-36 "Functional Capacity domain".

Conclusion

The AKSS adapted to Brazilian culture is useful and reliable for the evaluation of individuals with osteoarthritis or those who have undergone TKA.

Income and patient-reported outcomes (PROs) after primary total knee arthroplasty

BACKGROUND

To assess whether income is associated with patient-reported outcomes (PROs) after primary total knee arthroplasty (TKA).

METHODS

We used prospectively collected data from the Mayo Clinic Total Joint Registry to assess the association of income with index knee functional improvement, moderate to severe pain and moderate to severe activity limitation at 2-year and 5-year follow-up after primary TKA using multivariable-adjusted logistic regression analyses.

RESULTS

There were 7, 139 primary TKAs at 2 years and 4, 234 at 5 years. In multivariable-adjusted analyses, at 2-year follow-up, compared to income > US$45, 000, lower incomes of ≤ US$35, 000 and > US$35, 000 to 45, 000 were associated (1) significantly with moderate to severe pain with an odds ratio (OR) 0.61 (95% CI 0.40 to 0.94) (P = 0.02) and 0.68 (95% CI 0.49 to 0.94) (P = 0.02); and (2) trended towards significance for moderate to severe activity limitation with OR 0.78 (95% CI 0.60 to 1.02) (P = 0.07) and no significant association with OR 0.96 (95% CI 0.78 to 1.20) (P = 0.75), respectively. At 5 years, odds were not statistically significantly different by income, although numerically they favored lower income. In multivariable-adjusted analyses, overall improvement in knee function was rated as 'better' slightly more often at 2 years by patients with income in the ≤ US$35, 000 range compared to patients with income > US$45, 000, with an OR 1.9 (95% CI 1.0 to 3.6) (P = 0.06).

CONCLUSIONS

We found that patients with lower income had better pain outcomes compared to patients with higher income. There was more improvement in knee function, and a trend towards less overall activity limitation after primary TKA in lower income patients compared to those with higher incomes. Insights into mediators of these relationships need to be investigated to understand how income influences outcomes after TKA.

Single-step test for unilateral limb ability following total knee arthroplasty

STUDY DESIGN

Secondary analysis of a cohort enrolled in a prospective, randomized, longitudinal clinical trial.

OBJECTIVES

The single-step test (SST) was evaluated to assess its intertester reliability, validity as a test of activity limitation, and responsiveness to change for patients after unilateral total knee arthroplasty (TKA). The SST was also examined to determine whether it could differentiate between the surgical and nonsurgical lower limbs of patients after unilateral TKA and between the surgical limbs of patients after TKA and the limbs of healthy controls.

BACKGROUND

Tests of functional ability for patients recovering from TKA cannot differentiate the contribution of each limb to performance outcome. A test of unilateral limb ability would provide a metric for assessing the surgical lower extremity, without the confounder of the status of the contralateral lower extremity.

METHODS

Intertester reliability was assessed between clinicians and between a clinician and a switch mat. Patients who underwent unilateral TKA were tested at initial outpatient physical therapy evaluation, at 3 months after TKA, and at 1 year after TKA.

RESULTS

The assessment of function with the SST was determined to be reliable between testers when using a stopwatch. SST times were significantly correlated with other measures of lower extremity functional performance, providing evidence of its validity in patients after TKA. The SST was responsive to treatment in patients after TKA, with improvements in time for test completion. Performance on the SST also differed between limbs of patients after TKA and when comparing the limbs of healthy controls to those of patients after TKA.

CONCLUSION

The SST is a reliable measure between testers and a valid and responsive test of activity limitations when assessing unilateral lower extremity impairments in patients after TKA.

Lower extremity-specific measures of disability and outcomes in orthopaedic surgery

Outcome measures may be simple questions or complex measures that assess multiple interrelated domains affecting treatment outcomes. Outcome measures should be relevant to patients, easy to use, reliable, valid, and responsive to clinical changes. Joint and disease-specific outcome measures have been developed for the hip, knee, and foot and ankle. Many of these measures would benefit from further research into their validity, reliability, and optimal applicability. General health measures and activity level scores should be included in outcome assessments after treatment for orthopaedic conditions.

Knee instruments and rating scales designed to measure outcomes

In this article, the knee instruments and rating scales that are designed to measure outcomes are revised. Although the International Knee Documentation Committee Subjective Knee Form can be used as a general knee measure, no instrument is currently universally applicable across the spectrum of knee disorders and patient groups. Clinicians and researchers looking to use a patient-based score for measurement of outcomes must consider the specific patient population in which it has been evaluated. The Western Ontario and McMaster Universities Osteoarthritis Index is recommended for the evaluation of treatment effect in persons with osteoarthritis (OA). This is a generic health status questionnaire that contains 36 items, is widely used, and easy to complete. The Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire evaluates the functional status and quality of life (QoL) of patients with any type of knee injury who are at increased risk of developing OA; i.e., patients with anterior cruciate ligament (ACL) injury, meniscus injury, or chondral injury. So far, the KOOS questionnaire has been validated for several orthopedic procedures such as total knee arthroplasty, ACL reconstruction, and meniscectomy. The utilization of QoL questionnaires is crucial to the adequate assessment of a number of orthopedic procedures of the knee. The questionnaires are generally well accepted by the patients and open up new perspectives in the analysis of prognostic factors for optimal QoL of patients undergoing knee surgery.

Development of a new Knee Society scoring system

BACKGROUND

The Knee Society Clinical Rating System was developed in 1989 and has been widely adopted. However, with the increased demand for TKA, there is a need for a new, validated scoring system to better characterize the expectations, satisfaction, and physical activities of the younger, more diverse population of TKA patients.

QUESTIONS/PURPOSES

We developed and validated a new Knee Society Scoring System.

METHODS

We developed the new knee scoring system in two stages. Initially, a comprehensive survey of activities was developed and administered to 101 unilateral TKA patients (53 women, 48 men). A prototype knee scoring instrument was developed from the responses to the survey and administered to 497 patients (204 men, 293 women; 243 postoperatively, 254 preoperatively) at 15 medical institutions within the United States and Canada. Objective and subjective data were analyzed using standard statistical and psychometric procedures and compared to the Knee Injury and Osteoarthritis Score and SF-12 scores for validation. Based on this analysis, minor modifications led to the new Knee Society Scoring System.

RESULTS

We found the new Knee Society Scoring System to be broadly applicable and to accurately characterize patient outcomes after TKA. Statistical analysis confirmed the internal consistency, construct and convergent validity, and reliability of the separate subscale measures.

CONCLUSIONS

The new Knee Society Scoring System is a validated instrument based on surgeon- and patient-generated data, adapted to the diverse lifestyles and activities of contemporary patients with TKA. This assessment tool allows surgeons to appreciate differences in the priorities of individual patients and the interplay among function, expectation, symptoms, and satisfaction after TKA.

The importance to including objective functional outcomes in the clinical follow up of total knee arthroplasty patients

In clinical practice, it is increasingly important to assess patients' daily functionality routinely and objectively. Acceleration-based gait analysis (AGA) has shown to be reliable and technically suitable for routine clinical use outside the laboratory. This study investigated the suitability of AGA for measuring function in orthopaedic patients with symptomatic gonarthrosis listed for total knee arthroplasty (TKA) by investigating (a) the ability of AGA to distinguish patients from healthy subjects, (b) the sensitivity to gait changes of AGA in assessing recovery following total knee arthroplasty in a subpopulation, and (c) correlations between AGA parameters and clinical scales. Gait was assessed using AGA in 24 patients with symptomatic gonarthrosis listed for TKA, and in 24 healthy subjects. AGA parameters (e.g. speed, asymmetry) and clinical scales (e.g. KSS) were used to monitor progress in 12 patients 3 months after TKA. The Mann-Whitney-U test, Receiver Operating Characteristic (ROC) curves, repeated measurement ANOVA and Pearson correlations were performed. AGA differentiated pathological from healthy gait. The area under the ROC curve, sensitivity and specificity values were high for speed, step frequency and step length. Different recovery profiles were found, with clinical scales showing faster recovery rates. None or only weak correlations were found between AGA and clinical scores. AGA was found to be of clinical relevance in identifying and monitoring patients with symptomatic gonarthrosis in orthopaedic practice, providing objective and additional information about function beyond clinical scales. This, together with the fact that AGA can be applied routinely, suggests the suitability of AGA for use in rehabilitation programs.

Strategies Aimed at Preventing Chronic Post-surgical Pain: Comprehensive Perioperative Pain Management after Total Joint Replacement Surgery

PURPOSE

Chronic post-surgical pain (CPSP) is a frequent outcome of musculoskeletal surgery. Physiotherapists often treat patients with pain before and after musculoskeletal surgery. The purposes of this paper are (1) to raise awareness of the nature, mechanisms, and significance of CPSP; and (2) to highlight the necessity for an inter-professional team to understand and address its complexity. Using total joint replacement surgeries as a model, we provide a review of pain mechanisms and pain management strategies.

SUMMARY OF KEY POINTS

By understanding the mechanisms by which pain alters the body's normal physiological responses to surgery, clinicians selectively target pain in post-surgical patients through the use of multi-modal management strategies. Clinicians should not assume that patients receiving multiple medications have a problem with pain. Rather, the modern-day approach is to manage pain using preventive strategies, with the aims of reducing the intensity of acute postoperative pain and minimizing the development of CPSP.

CONCLUSIONS

The roles of biological, surgical, psychosocial, and patient-related risk factors in the transition to pain chronicity require further investigation if we are to better understand their relationships with pain. Measuring pain intensity and analgesic use is not sufficient. Proper evaluation and management of risk factors for CPSP require inter-professional teams to characterize a patient's experience of postoperative pain and to examine pain arising during functional activities.

Early functional outcome after subvastus or parapatellar approach in knee arthroplasty is comparable

PURPOSE

In total knee arthroplasty, tissue-sparing techniques are considered more important, as functional gain could become more advantageous when early mobilization is commenced. The parapatellar approach is most often used, whereas the subvastus approach is a suitable alternative. Presently, it is unknown, according to true objective measurements, which of the two is most advantageous.

METHODS

In this prospective randomized double-blind, short-term trial measurements (KSS, WOMAC, PDI, VAS, ability to perform) were obtained at day 1, day 3, 1 week, 6 weeks, and 3 months.

RESULTS

The subvastus group (n=20) showed only significantly less extension lag direct postoperative (P=0.04) compared with the parapatellar group (n=20). Other scores were not significantly different. The Dynaport®knee test, an objective performance-based tool, could not demonstrate significant differences. A blunt anatomical dissection was carried out in both observational and histological to support findings. A dense innervation of the distal vastus medialis was found. This is at risk employing the subvastus approach. Both approaches harm the suprapatellar bursa. The vastus medialis sheath must be detached distally to open the knee joint. No true separate vastus medialis obliquus could be identified.

CONCLUSION

Comparable to literature, only mild advantage employing the subvastus approach was found, but only early postoperative and not objectively. As this approach is also not suitable in every case, we will continue to use the parapatellar approach.

Correlations between commonly used clinical outcome scales and patient satisfaction after total knee arthroplasty

Patient satisfaction is becoming increasingly important as a crucial outcome measure for total knee arthroplasty. We aimed to determine how well commonly used clinical outcome scales correlate with patient satisfaction after total knee arthroplasty. In particular, we sought to determine whether patient satisfaction correlates better with absolute postoperative scores or preoperative to 12-month postoperative changes. Patient satisfaction was evaluated using 4 grades (enthusiastic, satisfied, noncommittal, and disappointed) for 438 replaced knees that were followed for longer than 1 year. Outcomes scales used the American Knee Society, Western Ontario McMaster University Osteoarthritis Index scales, and Short Form-36 scores. Correlation analyses were performed to investigate the relation between patient satisfaction and the 2 different aspects of the outcome scales: postoperative scores evaluated at latest follow-ups and preoperative to postoperative changes. The Western Ontario McMaster University Osteoarthritis Index scales function score was most strongly correlated with satisfaction (correlation coefficient=0.45). Absolute postoperative scores were better correlated with satisfaction than the preoperative to postoperative changes for all scales.

LEVEL OF EVIDENCE

Level IV (retrospective case series).

The development and validation of a functional assessment tool for the upper extremity in the overhead athlete

BACKGROUND

There are no validated upper extremity instruments designed specifically to evaluate the performance and function of overhead athletes. Current shoulder and elbow scoring systems may not be sensitive to subtle changes in performance in this high-demand population.

HYPOTHESIS

The scoring system developed in this study will be valid, reliable, and responsive in the evaluation of overhead athletes.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Based on the results of a pilot questionnaire administered to 21 overhead athletes, a final 10-item questionnaire was developed. Two hundred eighty-two healthy, competitive overhead athletes completed the new questionnaire, as well as 2 established upper extremity questionnaires, and were self-assigned into injury categories: (1) playing without pain, (2) playing with pain, and (3) not playing due to pain. Correlations between the scores and differences between injury categories were measured. Responsiveness testing was performed in an additional group of 55 injured athletes, comparing their scores before and after an intervention.

RESULTS

The new score showed high correlation with the Disabilities of the Arm, Shoulder and Hand (DASH) score and the DASH sports/performing arts module. The new score correctly stratified overhead athletes by injury category (P < .0001). The new score also demonstrated excellent responsiveness, varying appropriately with improvements in injury category after treatment of injuries (P < .05).

CONCLUSION

The new patient-reported instrument is valid and responsive in the evaluation of overhead athletes. Reliability was also demonstrated for the 13-item pilot questionnaire. The results support its use for the functional assessment of overhead athletes in future studies.

The visual analogue WOMAC 3.0 scale--internal validity and responsiveness of the VAS version

BACKGROUND

Many people suffer with Osteoarthritis (OA) and subsequent morbidity. Therefore, measuring outcome associated with OA is important. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) has been a widely used patient reported outcome in OA. However, there is relatively little evidence to support the use of the Visual Analogue Scale (VAS) version of the scale. We aimed to explore the internal validity and responsiveness of this VAS version of the WOMAC.

METHODS

Patients with chronic hip or knee pain of mechanical origin, waiting for a hip or knee joint replacement completed the WOMAC as part of a study to investigate the effects of acupuncture and placebo controls. Validity was tested using factor analysis and Rasch analysis, and responsiveness using standardised response means.

RESULTS

Two hundred and twenty one patients (mean age 66.8, SD 8.29, 58% female) were recruited. Factor and Rasch analysis confirmed unidimensional Pain and Physical Functioning scales, capable of transformation to interval scaling and invariant over time. Some Differential Item Functioning (DIF) was observed, but this cancelled out at the test level. The Stiffness scale fitted the Rasch model but adjustments for DIF could not be made due to the shortness of the scale. Using the interval transformed data, Standardised Response Means were smaller than when using the raw, ordinal data.

CONCLUSIONS

The WOMAC Pain and Physical Functioning subscales satisfied unidimensionality and ordinal scaling tests, and the ability to transform to an interval scale. Some Differential Item Functioning was observed, but this cancelled out at the test level and, by doing so, at the same time removed the disturbance of unidimensionality. The scaling characteristics of sets of items which use VAS require further analysis, as it would appear that they can lead to spurious levels of responsiveness and scale compression because they exaggerate the distortion of the ordinal scale.

TRIAL NUMBER

UKCRN study ID: 4881 ISRCTN78434638.

Use of a new high-activity arthroplasty score to assess function of young patients with total hip or knee arthroplasty

The High-Activity Arthroplasty Score (HAAS) was specifically developed to assess subtle variations in functional ability after lower limb arthroplasty with particular regard to highly functioning individuals. The score was a 4-item self-assessment measure covering the 4 domains of walking, running, stair climbing, and general activities, with a possible score ranging from 0 to 18 points. The score was validated in 22 patients (total hip arthroplasty [THA], n = 11; total knee arthroplasty [TKA], n = 11) by comparison with the Oxford, Knee Society, Harris Hip, and Short WOMAC scores. The HAAS was then administered to 152 high-functioning arthroplasty patients (THA, n = 99; TKA, n = 53), all younger than 66 years. The HAAS produced a much wider range of scores, allowing greater differentiation of level of function between patients in assessing performance after TKA or THA.

Determining patient concerns before joint arthroplasty

Despite the prevalence of studies relating to hip and knee arthroplasties, no Canadian studies exist in the literature regarding patients' perceptions and concerns prior to undergoing these procedures. A 32-question, 5-point Likert scale questionnaire was developed and administered to a Canadian cohort. One hundred fifty-six knee and 85 hip arthroplasty patients returned the survey. Results consistently showed complications arising from surgery, ways to reduce pain after surgery, and ability to walk properly again as the 3 top concerns for patients whether stratified by age, sex, residential status or joint replacement type. Other results discussed include resources used by patients to become better informed about joint arthroplasty, differences in Western Ontario and McMaster Universities Index of Osteoarthritis scores between groups, and significant differences in patient concerns as determined by ridit analyses.

Assessment of outcomes after hip arthroplasty

Because of the ever-increasing prevalence of joint replacement, it is important that patient outcomes after surgery are continuously reviewed and monitored, with the aim of optimising outcomes after surgery. Of central importance in assessing outcomes is choosing the most appropriate outcome measure. This article reviews five methods of assessing outcomes after hip arthroplasty, namely radiographic analysis, implant survivorship analysis, surgeon-based outcome measures, performance-related assessment and patient-reported outcome measures. The relative strengths and weaknesses of each method of assessment are discussed, with the aim of aiding the surgeon or researcher in choosing an outcome measure when designing a clinical trial.

Cost-benefit comparison of the Oxford Knee score and the American Knee Society score in measuring outcome of total knee arthroplasty

The American Knee Society score (AKSS) and the Oxford Knee score (OKS) are validated outcome measures for evaluation of total knee arthroplasties (TKAs). We investigated whether patient self-assessment using the OKS offers a viable alternative to clinical review using the AKSS. Preoperative, 2-year, 5-year, and 10-year postoperative OKS and AKSS were reviewed from TKA patients. The scores were analyzed using the Pearson correlation. There was good correlation of OKS and AKSS at 2 years. This implies that patient self-assessment is a viable screening tool to identify which patients require clinical review, at 2 years, after TKA. However, the moderate correlation at 5 and 10 years indicates that clinical evaluation remains necessary at these time points.

Gabapentin decreases morphine consumption and improves functional recovery following total knee arthroplasty

BACKGROUND

Moderate to severe pain after total knee arthroplasty often interferes with postoperative rehabilitation and delays discharge from hospital. The present study examined the effects of a four-day postoperative gabapentin (GBP) regimen versus placebo on opioid consumption, pain scores and knee flexion, as well as adverse effects, after total knee arthroplasty.

METHODS

After obtaining research ethics board approval and informed consent, 40 patients were enrolled in a randomized, single-blind, placebo-controlled, open-label study. Patients were assigned to one of five groups - preoperative placebo/postoperative placebo (G1), preoperative GBP 600 mg/postoperative placebo (G2), preoperative GBP 600 mg/postoperative GBP 100 mg three times per day (G3), preoperative GBP 600 mg/ postoperative GBP 200 mg three times per day (G4) and preoperative GBP 600 mg/postoperative GBP 300 mg three times per day (G5). Postoperative GBP or placebo was continued for four days after surgery. Two hours before surgery, all patients received celecoxib 400 mg. Based on the above groupings, patients in G1 received placebo medication, whereas patients in G2, G3, G4 and G5 received gabapentin 600 mg 2 h preoperatively. All patients received femoral and sciatic nerve blocks, followed by spinal anesthesia. Beginning in the postanesthetic care unit, all patients received a regimen of celecoxib 200 mg every 12 h for four days and a patient-controlled morphine analgesia pump for 48 h.

RESULTS

Thirty-six patients (G1, n=7; G2, n=7; G3, n=8; G4, n=7; G5, n=7) completed the study. Data were analyzed by one-way ANOVA followed by a contrast comparing patients who received postoperative GBP (G3, G4 and G5) (n=22) with patients who received placebo postoperatively (G1 and G2) (n=14). Patients who received GBP postoperatively used significantly less patient-controlled morphine analgesia at 24 h, 36 h and 48 h (P<0.05). The postoperative GBP patients had significantly better active assisted knee flexion on postoperative days 2 and 3, with a trend toward better flexion on postoperative day 4. Patients who received GBP postoperatively reported less pruritus than patients who received placebo. There were no differences in pain scores.

CONCLUSIONS

These results support the use of GBP in the acute postoperative period. Further trials are needed to delineate the optimal dose, timing and duration of GBP use following surgery.

Patella retention versus replacement in total knee arthroplasty; functional and clinimetric aspects

INTRODUCTION

Whether to resurface the patella or not in total knee arthroplasty still remains undecided. Classical scores and questionnaires might not be responsive or demanding enough. This study used two accelerometer based systems to study the hypothesis whether performance based tests are able to detect a difference in patients with or without a resurfaced patella.

METHOD

In this retrospective study 53 patients were included and divided into a resurfaced group (n = 31) and a non-resurfaced group (n = 22). Both groups were matched on age and longevity of follow up. Patients were clinically assessed using the Knee Society Score (KSS) at various time points. At final follow up patients were also assessed once using the Dynaport Knee Test and the Minimod Gait Test.

RESULTS

The Dynaport Knee Test showed a significant functional advantage for patients with a resurfaced patella [44 vs. 39.7 (P = 0.042)], whereas KSS and The Minimod were not significant (P values ranging from 0.07 to 0.75). Similar to other reports in literature, using the KSS, it was not possible to identify significant difference between patella resurfacing or retaining in total knee arthroplasty, however using a performance based test it was possible to determine significant difference. The found advantage of patella resurfacing may be less due to pain relief but due to a functional benefit during demanding motion tasks. This finding indicates that current measurement tools may not be accurate or specific enough to detect this difference. Therefore, we recommend complementing the classic evaluation tools with an objective functional test, when conducting a randomized trial to answer the indecision whether to resurface the patella or not.

Correlation between objective gait parameters and subjective score measurements before and after total knee arthroplasty

The absence of uniformity, the use of different terminologies, and the diversity of methods used to translate numerical data into clinical outcomes have been described as potential problems when dealing with clinical knee scores for total knee arthroplasty (TKA). Gait analysis is believed to provide more objective parameters. The aim of the present study was to obtain information about the correlation between the outcome in terms of locomotion and the clinical knee score after TKA. Thirty consecutive patients awaiting TKA were involved in the study. One day prior to surgery and 3 months postoperatively, data pertaining to the Hospital for Special Surgery Score (HSS) and the Knee Society Score (KSS) (subgroups 'pain', 'knee', 'function' and 'total sum') were analyzed for correlations with kinematic and temporospatial parameters of gait analysis. At a significance-level of p</=0.001 moderate correlations (0.4<r<0.6) were found preoperatively, particularly between 'max knee flexion swing' and the function-subscores of HSS and KSS and the 'KSS total'. High correlations (0.6<r<0.8) were ascertained for 'stride length' and 'gait velocity' with 'KSS function'. High correlations were also determined between 'stride length' and 'KSS total' and between 'gait velocity' and 'HSS function'. The only correlation found postoperatively was between 'max pelvic obliquity stance' and 'KSS knee' (r=0.770, p<0.001). We conclude that the 'function' subscores of KSS and HSS are highly suitable to assess the functional capacity of patients scheduled for TKA. However, because no adequate correlations between knee scores and gait parameter were found postoperatively, we cannot recommend the abandonment of gait analysis when monitoring the functional benefit of TKA.

Small increase of actual physical activity 6 months after total hip or knee arthroplasty

Limitation in daily physical activity is one of the reasons for total hip arthroplasty (THA) or total knee arthroplasty (TKA). However, studies of the effects of THA or TKA generally do not determine actual daily activity as part of physical functioning. We determined the effect of THA or TKA on patients' actual physical activity and body function (pain, stiffness), capacity to perform tasks, and self-reported physical functioning. We also assessed whether there are differences in the effect of the surgery between patients undergoing THA or TKA and whether the improvements vary between these different outcome measures. We recruited patients with long-standing end-stage osteoarthritis of the hip or knee awaiting THA or TKA. Measurements were performed before surgery and 3 and 6 months after surgery. Actual physical activity improved by 0.7%. Patients' body function, capacity, and self-reported physical functioning also improved. The effects of the surgery on these aspects of physical functioning were similar for THA and TKA. The effect on actual physical activity (8%) was smaller than on body function (80%-167%), capacity (19%-36%), and self-reported physical functioning (87%-112%). Therefore, in contrast to the large effect on pain and stiffness, patients' capacity, and their self-reported physical functioning, the improvement in actual physical activity of our patients was less than expected 6 months after surgery.

LEVEL OF EVIDENCE

Level I, prospective study. See the Guidelines for Authors for a complete description of levels of evidence.

Magnitude and meaningfulness of change in SF-36 scores in four types of orthopedic surgery

Background

The Medical Outcomes General Health Survey (SF-36) is a widely used health status measure; however, limited evidence is available for its performance in orthopedic settings. The aim of this study was to examine the magnitude and meaningfulness of change and sensitivity of SF-36 subscales following orthopedic surgery.

Methods

Longitudinal data on outcomes of total hip replacement (THR, n = 255), total knee replacement (TKR, n = 103), arthroscopic partial meniscectomy (APM, n = 74) and anterior cruciate ligament reconstruction (ACL, n = 62) were used to estimate the effect sizes (ES, magnitude of change) and minimal detectable change (sensitivity) at the group and individual level. To provide context for interpreting the magnitude of changes in SF-36 scores, we also compared patients' scores with age and sex-matched population norms. The studies were conducted in Sweden. Follow-up was five years in THR and TKR studies, two years in ACL, and three months in APM.

Results

On average, large effect sizes (ES≥0.80) were found after orthopedic surgery in SF-36 subscales measuring physical aspects (physical functioning, role physical, and bodily pain). Small (0.20–0.49) to moderate (0.50–0.79) effect sizes were found in subscales measuring mental and social aspects (role emotional, vitality, social functioning, and mental health). General health scores remained relatively unchanged during the follow-up. Despite improvements, post-surgery mean scores of patients were still below the age and sex matched population norms on physical subscales. Patients' scores on mental and social subscales approached population norms following the surgery. At the individual level, scores of a large proportion of patients were affected by floor or ceiling effects on several subscales and the sensitivity to individual change was very low.

Conclusion

Large to moderate meaningful changes in group scores were observed in all SF-36 subscales except General Health across the intervention groups. Therefore, in orthopedic settings, the SF-36 can be used to show changes for groups in physical, mental, and social dimensions and in comparison with population norms. However, SF-36 subscales have low sensitivity to individual change and so we caution against using SF-36 to monitor the health status of individual patients undergoing orthopedic surgery.