No differences in objective dynamic instability during acceleration of the knee with or without subjective instability post-total knee arthroplasty

Do Patient Reported Outcomes Reflect Objective Measures of Function? Implications for Total Knee Arthroplasty

BACKGROUND

Patient Reported Outcomes (PROs) are used in research, clinical practice, and by federal reimbursement models to assess outcomes for patients who have knee osteoarthritis (OA) and total knee arthroplasty (TKA). We examined a large cohort of patients to determine if commonly used PROs reflect observed evaluation as measured by standardized functional tests (SFTs).

METHODS

We used data from the Osteoarthritis Initiative, a ten-year observational study of knee osteoarthritis patients. Two cohorts were examined: 1) participants who received TKA (n=281) and 2) participants who have native OA (n=4,687). The PROs included Western Ontario and McMaster Osteoarthritis Index (WOMAC), Knee Injury and Osteoarthritis Outcome Score (KOOS), 12-Item Short Form Health Survey (SF-12), and Intermittent and Constant Pain Score (ICOAP). The SFTs included 20 and 400 meter (M) walks and chair stand pace. Repeated measures correlation coefficients were used to determine the relationship between PROs and SFTs.

RESULTS

The PROs and SFTs were not strongly correlated in either cohort. The magnitude of the repeated measures correlation (r_rm) between KOOS, WOMAC, SF-12, and ICOAP scores and SFT measurements in native knee OA patients ranged as follows: 400 M walk pace (0.08 to 0.20), chair stand pace (0.05 to 0.12), and 20 M pace (0.02 to 0.21), all with P<0.05. In the TKA cohort, values ranged as follows: 400 M walk pace (0.00 to 0.29), chair stand time (0.02 to 0.23), and 20 M pace (0.03 to 0.30). Due to the smaller cohort size, the majority, but not all had P values <0.05.

CONCLUSION

There is not a strong association between PROs and SFTs among patients who have knee OA or among patients who received a TKA. Therefore, PROs should not be used as a simple proxy for observed evaluation of physical function. Rather, PROs and SFTs are complementary and should be used in combination for a more nuanced and complete characterization of outcome.

Usefulness of gait parameters obtained from inertial sensors attached to the lower trunk and foot for assessment of gait performance in the early postoperative period after total knee arthroplasty

BACKGROUND

This study was performed to (i) compare gait parameters obtained from inertial sensors attached to the lower trunk and foot between patients in the early postoperative period after total knee arthroplasty (TKA) and healthy age- and sex-matched controls and (ii) elucidate the association between the gait parameters and patient-reported outcome measures (PROMs).

METHOD

The gait performance of 19 patients who had undergone TKA was assessed using inertial sensors and PROMs obtained from the Knee Injury and Osteoarthritis Outcome Score (KOOS) 1 week before hospital discharge. The patients walked along a 15-m walkway and we calculated the following gait parameters: walking speed, coefficient of variation (CV) of stride time, unbiased autocorrelation coefficient (AC), harmonic ratio (HR), and symmetry index (SI). The same gait parameter data from 19 age- and sex-matched healthy adults (controls) were obtained from our past study.

RESULTS

The TKA group demonstrated slower walking speed, larger CV of stride time, lower HR in all three directions, lower AC in the vertical direction, and higher SI in the vertical direction than the healthy control group (all p < 0.05). Correlation analysis revealed that the SI in the anteroposterior direction was significantly correlated with the KOOS symptoms subscore and ADL subscore (p < 0.05).

CONCLUSIONS

Patients in the early postoperative period after TKA exhibited worse gait performance as assessed by inertial sensors compared with healthy controls. Gait symmetry was correlated with PROMs. These results indicate the usefulness of assessing gait parameters after TKA.

Inter-Rater Reliability of Clinical Testing for Laxity After Knee Arthroplasty

BACKGROUND

The clinical examination for laxity has been considered a mainstay in evaluation of the painful knee arthroplasty, especially for the diagnosis of instability. More than 10 mm of anterior-posterior (AP) translation in flexion has been described as important in the diagnosis of flexion instability. The inter-observer reliability of varus/valgus and AP laxity testing has not been tested.

METHODS

Ten subjects with prior to total knee arthroplasty (TKA) were examined by 4 fellowship-trained orthopedic knee arthroplasty surgeons. Each surgeon evaluated each subject in random order and was blinded to the results of the other surgeons. Each surgeon performed an anterior drawer test at 30 and 90 degrees of flexion and graded the instability as 0-5 mm, 5-10 mm or >10 mm. Varus-valgus testing was also graded. Motion capture was used during the examination to determine the joint position and estimate joint reaction force during the examination.

RESULTS

Inter-rater reliability (IRR) was poor at 30 and 90 degrees for both the subjective rater score and the measured AP laxity in flexion (k = 018-0.22). Varus-valgus testing similarly had poor reliability. Force applied by the rater also had poor IRR.

CONCLUSION

Clinical testing of knee laxity after TKA has poor reliability between surgeons using motion analysis. It is unclear if this is from differences in examiner technique or from differences in pain or quadriceps function of the subjects. Instability after TKA should not be diagnosed strictly by clinical testing and should involve a complete clinical assessment of the patient.

Can tibio-femoral kinematic and kinetic parameters reveal poor functionality and underlying deficits after total knee replacement? A systematic review

BACKGROUND

Extensive efforts have been made to understand joint kinematics and kinetics in total knee arthroplasty (TKA) in subjects with satisfactory outcomes during daily functional activities and clinical tests, but it remains unclear whether such movement characteristics hold the potential to indicate the underlying aetiology of unsatisfactory or bad TKA outcomes.

PURPOSE

To investigate which kinematic and kinetic parameters assessed during passive clinical tests and functional activities of daily living are associated with poor functionality and underlying deficits after total knee replacement.

METHODS

We focused on studies characterizing the kinematic or kinetic parameters of the knee joint that are associated with poor clinical outcome after TKA. Seventeen articles were included for the review, and kinematic and kinetic data from 719 patients with minimal follow up of 6 months were extracted and analyzed.

RESULTS

Passive posterior translation at 90°flexionexhibited good potential for differentiating stable and unstable TKAs. Anterior-posterior (A-P) translation of the medial condyle at 0-30° and 30-60° flexion, A-P translation of the lateral condyle at 60-90°during closed chain exercises, as well asknee extension moment during stair ascent and descent, knee abduction moment during stair descent, knee internal rotation moment and plantar flexion moment during walking, 2ndpeak ground reaction force during stair ascent and walkingshowed the greatest promise as functional biomarkers for a dissatisfied/poor outcome knee after TKA.

CONCLUSION

In this study, we systematically reviewed the state-of-the-art knowledge of kinematics and kinetics associated with functional deficits, and found 11 biomechanical parameters that showed promise for supportingdecision making in TKA.

Gait Analysis 1 Year after Primary TKA: No Difference between Gap Balancing and Measured Resection Technique

Mechanical alignment in total knee arthroplasty (TKA) can be achieved using dependent bone cuts. The hypothesis is that patients have a better balanced TKA, as a result. The aim of this study was to determine if this technique is superior to an independent bone cut technique in terms of gait parameters, patient-reported outcome measures (PROMs), and satisfaction assessed before surgery and at 1-year follow-up. A total of 58 patients were evaluated before and 1 year following TKA, using the Press Fit Condylar (PFC) Sigma posterior stabilizer (PS) design; 39 (70 ± 8 years; 27 women) with independent bone cuts and 19 (71 ± 7 years; 12 women) with dependent bone cuts using the Specialist TRAM. Gait was evaluated with a three-dimensional motion analysis system for spatiotemporal and kinematics parameters. Pain and functional levels were assessed using the Western Ontario and McMaster Universities arthritis index (WOMAC); general health was assessed by the short form (SF)-12. Global satisfaction, as well as patient satisfaction, related to pain and functional levels were assessed using a five-point Likert's scale. No significant difference was found between both groups in terms of age, body mass index, pain, and functional levels at baseline. At 1-year follow-up, despite an overall improvement in gait, WOMAC, SF-12 physical score and pain, none of the patients showed gait parameters comparable to a healthy control group. No surgical technique effect was observed on gait, clinical outcomes, and satisfaction level. While observing an overall improvement at 1-year follow-up, we did not find any significant difference between the two surgical techniques in terms of gait parameters, patients' outcomes, and satisfaction.

Correlation of quality of life with instrumented analysis of a total knee arthroplasty series at the long-term follow-up

PURPOSE

The relationship between instrumented knee measurements and patient-reported outcome measures is a newer field that continues to evolve. The aim of this study was to evaluate long-term quality of life (QoL) post-total knee arthroplasty (TKA) surgery correlating validated self-reported questionnaires, clinical examination and instrumented analysis, using baropodometry and accelerometry.

METHODS

Thirty-six patients who underwent primary unilateral TKA between 1999 and 2006 were evaluated at 11.3 ± 2.3 years following surgery. Clinical examination included range of motion (ROM) and instrumented knee laxity measurements with the Rolimeter device. The visual analogue scale (VAS) for pain was also recorded. The utilised subjective outcome scores were the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the short form of World Health Organisation Quality of Life (WHOQOL-BREF). Instrumented analysis was performed with baropodometry and accelerometry. QoL was assessed correlating clinical, subjective and instrumented results. Univariate analysis included the Spearman's Rho correlation coefficient and Mann-Whitney tests.

RESULTS

At the long-term follow-up all patients had relatively high quality of life measurements, as well as functional scores, except for the Sport/Rec dimension of the KOOS score. Only cadence (p = 0.008) and velocity (p = 0.026) affected the WHOQOL psychology domain no matter the age, follow-up and gender of the patients. The domain was unaffected by VAS and Rolimeter measurements. WHOQOL Social domain was unaffected by all instrumentation measurements except for stance phase (p = 0.025), VAS (p = 0.005) and ROM (p = 0.028). KOOS physical domain was not affected by any parameter. KOOS pain was reversely affected by VAS (p = 0.004), KOOS symptom by ROM (p = 0.000 and median maximum pressure (p = 0.033).

CONCLUSION

Quality of life for the TKA patient can be correlated and assessed reliably with instrumented analysis using pedobarography and accelerometry, at the long-term follow-up.

LEVEL OF EVIDENCE

III.

Current clinical utilisation of wearable motion sensors for the assessment of outcome following knee arthroplasty: a scoping review

OBJECTIVES

Wearable motion sensors are used with increasing frequency in the evaluation of gait, function and physical activity within orthopaedics and sports medicine. The integration of wearable technology into the clinical pathway offers the ability to improve post-operative patient assessment beyond the scope of current, questionnaire-based patient-reported outcome measures. This scoping review assesses the current methodology and clinical application of accelerometers and inertial measurement units for the evaluation of patient activity and functional recovery following knee arthroplasty.

DESIGN

This is a systematically conducted scoping review following Joanna Briggs Institute methodology for scoping reviews and reported consulting the Preferred Reporting Items for Systematic Review and Meta-Analyses extension for scoping reviews. A protocol for this review is registered with the Open Science Framework (https://osf.io/rzg9q).

DATA SOURCES

CINAHL, EMBASE, MEDLINE and Web of Science databases were searched for manuscripts published between 2008 and 2019.

ELIGIBILITY CRITERIA

We included clinical studies reporting the use of any combination of accelerometers, pedometers or inertial measurement units for patient assessment at any time point following knee arthroplasty.

DATA EXTRACTION AND SYNTHESIS

Data extracted from manuscripts included patient demographics, sensor technology, testing protocol and sensor-based outcome variables.

RESULTS

45 studies were identified, including 2076 knee arthroplasty patients, 620 patients with end-stage osteoarthritis and 449 healthy controls. Primary aims of the identified studies included functional assessment, physical activity monitoring and evaluation of knee instability. Methodology varied widely between studies, with inconsistency in reported sensor configuration, testing protocol and output variables.

CONCLUSIONS

The use of wearable sensors in evaluation of knee arthroplasty procedures is becoming increasingly common and offers the potential to improve clinical understanding of recovery and rehabilitation. While current studies lack consistency, significant opportunity exists for the development of standardised measures and protocols for function and physical activity evaluation.

Computational analysis of knee joint stability following total knee arthroplasty

The overall objective of this study was to introduce knee joint power as a potential measure to investigate knee joint stability following total knee arthroplasty (TKA). Specific aims were to investigate whether weakened knee joint stabilizers cause abnormal kinematics and how it influences the knee joint kinetic (i.e., power) in response to perturbation. Patient-specific musculoskeletal models were simulated with experimental gait data from six TKA patients (baseline models). Muscle strength and ligament force parameter were reduced by up to 30% to simulate weak knee joint stabilizers (weak models). Two different muscle recruitment criteria were tested to examine whether altered muscle recruitment pattern can mask the influence of weakened stabilizers on the knee joint kinematics and kinetics. Level-walking knee joint kinematics and kinetics were calculated though force-dependent kinematic and inverse dynamic analyses. Bode analysis was then recruited to estimate the knee joint power in response to a simulated perturbation. Weak models resulted in larger anterior-posterior (A-P) displacement and internal-external (I-E) rotation compared to baseline (I-E: 18.4 ± 8.5 vs. 11.6 ± 5.7 (deg), A-P: 9.7 ± 5.6 vs. 5.5 ± 4.1 (mm)). Changes in muscle recruitment criterion however altered the results such that A-P and I-E were not notably different from baseline models. In response to the simulated perturbation, weak models versus baseline models generated a delayed power response with unbounded magnitudes. Perturbed power behavior of the knee remained unaltered regardless of the muscle recruitment criteria. In conclusion, impairment at the knee joint stabilizers may or may not lead to excessive joint motions but it notably affects the knee joint power in response to a perturbation. Whether perturbed knee joint power is associated with the patient-reported outcome requires further investigation.

The assessment of instability in the osteoarthritic knee

Patient-reported instability is a common complaint amongst those with knee arthritis.

Much research has examined the assessment of self-reported instability in the knee; however, no definitive quantitative measure of instability has been developed.

This review focuses on the current literature investigating the nature of self-reported instability in the arthritic knee and discusses the possibilities of further investigation.

Cite this article: EFORT Open Rev 2019;4:70-76. DOI: 10.1302/2058-5241.4.170079