Choice of Patient-Reported Outcome Measures for Midterm Assessment After Anterior Cruciate Ligament Reconstruction Surgery.

BACKGROUND: Patient-reported outcome measures (PROMs) have become increasingly popular for assessing subjective elements of a patient's condition. Two frequently used knee-related PROMs after anterior cruciate ligament reconstruction (ACLR) surgery are the International Knee Documentation Committee Subjective Knee Form (IKDC-SKF) and the Knee injury and Osteoarthritis Outcome Score (KOOS). However, completing the full versions of both measures represents a considerable responder burden. PURPOSE: To compare a variety of KOOS short forms with each other as well as the IKDC-SKF in a large sample of ACLR patients between 2 and 6 years after surgery. STUDY DESIGN: Cohort study (Diagnosis); Level of evidence, 2. METHODS: The KOOS and IKDC-SKF were administered between 2 and 6 years (mean, 3 years) after ACLR surgery to a cohort of 832 patients (men, n = 489; women, n = 343). Two single-item assessment numerical evaluations were also completed for knee function and satisfaction. The following short form versions were calculated from the full KOOS: the KOOS-12 short form, KOOS-Physical Function Short form (KOOS-PS), KOOS-Joint Replacement Short form (KOOS-JR), and KOOS-Global. Descriptive statistics were calculated for all PROMs and associations between measures were explored using nonparametric (Spearman rho) correlations. Floor or ceiling effects were considered present if >15% of patients reported the worst (floor effect) or best (ceiling effect) possible score. Age and sex comparisons were also made for each PROM. RESULTS: Ceiling effects were present for all KOOS short form versions. They were highly evident for the KOOS-JR and KOOS-PS (37%-44%), but they were only marginally above the threshold for the KOOS-12 and KOOS-Global (16%). The KOOS-12 and KOOS-Global had the highest correlation with the IKDC-SKF but only explained 58% to 59% of the variance in scores. The KOOS-12 and KOOS-Global were very highly correlated (ρ = 0.98). Only moderate correlations were seen between the single-item assessments and the IKDC-SKF or various KOOS short forms. There was a negligible association between patient age and PROM scores, but there was no significant sex difference for any of the PROMs. CONCLUSION: The IKDC-SKF together with either the KOOS-Global or KOOS-12 may provide a comprehensive range of knee-related PROMs with minimized responder burden at 2 to 6 years after ACLR.

Risk assessment and management of primary patellar dislocation is complex and multifactorial: a survey of Australian knee surgeons.

OBJECTIVES: Recurrent patellar instability following first-time lateral patellar dislocation is associated with a variety of bony, soft tissue and patient-related risk factors. The specific management of recurrent dislocation may vary depending on the presence and combination of these factors as well as the treating physician's interpretation of these. Therefore, this study aimed to determine which factors Australian knee surgeons regard as increasing the risk of recurrence following first-time patellar dislocation and to characterise the surgical decision-making process of these surgeons in the management of lateral patellar instability. METHODS: An online survey was sent to all active members of the Australian Knee Society (AKS). The survey addressed (i) risk factors for recurrence following first-time patellar dislocation and (ii) the surgical decision-making process in treating patellar instability. RESULTS: Seventy-seven per cent (53 of 69) Australian Knee Society members responded. Factors identified by respondents as significantly increasing the risk of recurrence were a history of contralateral recurrent patellar dislocation (74% respondents), an atraumatic injury mechanism (57%), trochlear dysplasia (49%) younger age (45%), patella alta (43%) and generalised ligamentous laxity (42%). Forty-four per cent replied that there may be an indication for surgical intervention following first-time patellar dislocation with no apparent loose body present. All respondents would recommend operative management of recurrent patellar dislocation after a third episode, with 45% of surgeons recommending surgery after a second episode. The most common surgical procedures performed by respondents were medial patellofemoral ligament (MPFL) reconstruction (94%), tibial tuberosity medialisation (91%) and tibial tuberosity distalisation (85%). Only 23% of respondents consider trochleoplasty for primary surgical intervention. CONCLUSION: Surgeons identified a large number of factors that they use to assess risk of recurrence following first-time patellar dislocation, many of which are not supported by the literature. The two highest ranked factors (history of contralateral recurrent patellar dislocation and an atraumatic injury mechanism) are without a significant evidence base. There was considerable variation in the criteria used to make the decision to perform a patellar stabilisation procedure. MPFL reconstruction was the most commonly used procedure, either in isolation or combined with another procedure. LEVEL OF EVIDENCE: Cross-sectional study; expert opinion (Level V).

Perceptions about participation in a 12-week walking program for people with severe knee osteoarthritis: a qualitative analysis.

PURPOSE: To explore the perceptions of people with severe knee osteoarthritis and increased cardiovascular risk about participating in a walking program. METHODS: Qualitative study using semistructured interviews for people with severe knee osteoarthritis and increased cardiovascular risk who participated in a 12-week walking program. Interviews were audiotaped, transcribed verbatim, member-checked, coded and themes developed using thematic analysis. Findings were triangulated with quantitative data including pain, function and cardiovascular risk factors from previously reported data. RESULTS: Twenty-one participants were interviewed after the completion of the walking program. The main theme identified was the preoccupation with the knee including pain, damage and the view that surgery was required. Three subthemes to emerge were (i) the perception of functional, cardiovascular and psychosocial benefits with the walking program; (ii) that supervision, monitoring and commitment were important enablers; and (iii) external factors such as ill-health, weather and the environment were key barriers. The perceived functional and cardiovascular benefits converged with results from quantitative data. CONCLUSIONS: Even when patients with severe osteoarthritis of the knee report other benefits from participating in a walking program, the core theme to emerge was their preoccupation with knee pain, knee damage and the view that they needed a knee replacement. Implications for Rehabilitation Patients with severe osteoarthritis of the knee and moderate cardiovascular risk reported functional, cardiovascular and psychosocial benefits from participating in a walking program. Despite patients reporting functional, cardiovascular and psychosocial benefits, the core theme to emerge was their preoccupation with knee pain, knee damage and the view that they needed a knee replacement. The core theme highlights the challenges in promoting physical activity for patients with severe knee osteoarthritis.

Assessment of Gait Characteristics in Total Knee Arthroplasty Patients Using a Hierarchical Partial Least Squares Method.

Quantitative gait analysis is an important tool in objective assessment and management of total knee arthroplasty (TKA) patients. Studies evaluating gait patterns in TKA patients have tended to focus on discrete data such as spatiotemporal information, joint range of motion and peak values of kinematics and kinetics, or consider selected principal components of gait waveforms for analysis. These strategies may not have the capacity to capture small variations in gait patterns associated with each joint across an entire gait cycle, and may ultimately limit the accuracy of gait classification. The aim of this study was to develop an automatic feature extraction method to analyse patterns from high-dimensional autocorrelated gait waveforms. A general linear feature extraction framework was proposed and a hierarchical partial least squares method derived for discriminant analysis of multiple gait waveforms. The effectiveness of this strategy was verified using a dataset of joint angle and ground reaction force waveforms from 43 patients after TKA surgery and 31 healthy control subjects. Compared with principal component analysis and partial least squares methods, the hierarchical partial least squares method achieved generally better classification performance on all possible combinations of waveforms, with the highest classification accuracy . The novel hierarchical partial least squares method proposed is capable of capturing virtually all significant differences between TKA patients and the controls, and provides new insights into data visualization. The proposed framework presents a foundation for more rigorous classification of gait, and may ultimately be used to evaluate the effects of interventions such as surgery and rehabilitation.

Clinic-based assessment of weight-bearing asymmetry during squatting in people with anterior cruciate ligament reconstruction using Nintendo Wii Balance Boards.

OBJECTIVE: To use low-cost Nintendo Wii Balance Boards (NWBB) to assess weight-bearing asymmetry (WBA) in people who have undergone anterior cruciate ligament reconstruction (ACLR), and to compare their results with a matched control group. DESIGN: Quantitative clinical study using a cross-sectional design. SETTING: Orthopedic clinic of a private hospital. PARTICIPANTS: ACLR participants (n=41; mean age ± SD, 26.0 ± 9.8 y; current Cincinnati sports activity level, 75.3 ± 19.8) performed testing in conjunction with their routine 6- or 12-month clinical follow-up, and a control group (n=41) was matched for age, height, body mass, and physical activity level. INTERVENTIONS: Participants performed double-limb squats while standing on 2 NWBBs, 1 under each foot. MAIN OUTCOME MEASURES: The WBA variables mean mass difference as a percentage of body mass, time favoring a single limb by >5% body mass, absolute symmetry index, and symmetry index relative to the operated or matched control limb were derived. Mann-Whitney U tests were performed to assess between-group differences. RESULTS: Significant (P<.05) increases in asymmetry in the ACLR group were found for all outcome measures except symmetry index relative to the operated limb. CONCLUSIONS: People who have undergone ACLR are likely to possess WBA during squats, and this can be assessed using low-cost NWBBs in a clinical setting. Interestingly, the observed asymmetry was not specific to the surgical limb. Future research is needed to assess the relationship between WBA early in the rehabilitation process and long-term outcomes.

Assessment of standing balance deficits in people who have undergone anterior cruciate ligament reconstruction using traditional and modern analysis methods.

Modern methods of assessing standing balance such as wavelet and entropy analysis could provide insight into postural control mechanisms in clinical populations. The aim of this study was to examine what effect anterior cruciate ligament reconstruction (ACLR) has on traditional and modern measures of balance. Ninety subjects, 45 who had undergone ACLR and 45 matched controls, performed single leg static standing balance tests on their surgical or matched limb on a Nintendo Wii Balance Board. Data were analysed in the anterior-posterior axis of movement, which is known to be affected by ACLR. The traditional measures of path velocity, amplitude and standard deviation were calculated in this plane. Additionally, sample entropy and discrete wavelet transform derived assessment of path velocity in four distinct frequency bands related to (1) spinal reflexive loops and muscle activity, (2) cerebellar, (3) vestibular, and (4) visual mechanisms of postural control were derived. The ACLR group had significantly increased values in all traditional measures and all four frequency bands. No significant difference was observed for sample entropy. This indicated that whilst postural sway was amplified in the ACLR group, the overall mechanism used by the patient group to maintain balance was similar to that of the control group. In conclusion, modern methods of signal analysis may provide additional insight into standing balance mechanisms in clinical populations. Future research is required to determine if these results provide important and unique information which is of benefit to clinicians.

The assessment of postural control and the influence of a secondary task in people with anterior cruciate ligament reconstructed knees using a Nintendo Wii Balance Board.

BACKGROUND: Postural control impairments may persist following anterior cruciate ligament (ACL) reconstruction. The effect of a secondary task on postural control has, however, not been determined. The purpose of this case-control study was to compare postural control in patients following ACL reconstruction with healthy individuals with and without a secondary task. PARTICIPANTS: 45 patients (30 men and 15 women) participated at least 6 months following primary ACL reconstruction surgery. Participants were individually matched by age, gender and sports activity to healthy controls. MATERIALS: Postural control was measured using a Nintendo Wii Balance Board and customised software during static single-leg stance and with the addition of a secondary task. The secondary task required participants to match the movement of an oscillating marker by adducting and abducting their arm. MAIN OUTCOME MEASURES: Centre of pressure (CoP) path length in both medial-lateral and anterior-posterior directions, and CoP total path length. RESULTS: When compared with the control group, the anterior-posterior path length significantly increased in the ACL reconstruction patients' operated (12.3%, p=0.02) and non-operated limbs (12.8%, p=0.02) for the single-task condition, and the non-operated limb (11.5%, p=0.006) for the secondary task condition. The addition of a secondary task significantly increased CoP path lengths in all measures (p<0.001), although the magnitude of the increase was similar in both the ACL reconstruction and control groups. DISCUSSION: ACL reconstruction patients showed a reduced ability in both limbs to control the movement of the body in the anterior-posterior direction. The secondary task affected postural control by comparable amounts in patients after ACL reconstruction and healthy controls. Devices for the objective measurement of postural control, such as the one used in this study, may help clinicians to more accurately identify patients with deficits who may benefit from targeted neuromuscular training programs.

Validity of the Microsoft Kinect for assessment of postural control.

Clinically feasible methods of assessing postural control such as timed standing balance and functional reach tests provide important information, however, they cannot accurately quantify specific postural control mechanisms. The Microsoft Kinect™ system provides real-time anatomical landmark position data in three dimensions (3D), and given that it is inexpensive, portable and simple to setup it may bridge this gap. This study assessed the concurrent validity of the Microsoft Kinect™ against a benchmark reference, a multiple-camera 3D motion analysis system, in 20 healthy subjects during three postural control tests: (i) forward reach, (ii) lateral reach, and (iii) single-leg eyes-closed standing balance. For the reach tests, the outcome measures consisted of distance reached and trunk flexion angle in the sagittal (forward reach) and coronal (lateral reach) planes. For the standing balance test the range and deviation of movement in the anatomical landmark positions for the sternum, pelvis, knee and ankle and the lateral and anterior trunk flexion angle were assessed. The Microsoft Kinect™ and 3D motion analysis systems had comparable inter-trial reliability (ICC difference=0.06±0.05; range, 0.00-0.16) and excellent concurrent validity, with Pearson's r-values >0.90 for the majority of measurements (r=0.96±0.04; range, 0.84-0.99). However, ordinary least products analyses demonstrated proportional biases for some outcome measures associated with the pelvis and sternum. These findings suggest that the Microsoft Kinect™ can validly assess kinematic strategies of postural control. Given the potential benefits it could therefore become a useful tool for assessing postural control in the clinical setting.

Physiological falls risk assessment in older people with Alzheimer's disease.

BACKGROUND: Falls are common in people with Alzheimer's disease (AD). There is some evidence that deficits in vision, peripheral sensation, strength, reaction time and balance may be partly responsible for this increased risk. AIMS: To determine the feasibility and test-retest reliability of a physiological test battery designed to assess falls risk [the Physiological Profile Assessment (PPA)] in people with AD, and to compare their PPA scores to age- and sex-matched controls. METHODS: Twenty-one community-dwelling people with probable, mild to moderate AD aged 63-91 years, and 21 age- and sex-matched controls underwent the PPA tests and the Mini-Mental State Examination. All tests were then repeated in the AD group to determine test-retest reliability. RESULTS: Most of the PPA tests could be successfully administered to participants with AD. The AD group had a significantly higher overall falls risk score (t(40) = -2.41, p < 0.02), slower hand (t(40) = -4.86, p < 0.01) and foot reaction time (t(40) = -2.26, p < 0.05) and worse coordinated stability (t(40) = -2.40, p < 0.05) than the controls. CONCLUSION: Physiological falls risk assessment is feasible in older people with mild to moderate AD. Older people with AD demonstrate significant impairments in several physiological domains, particularly reaction time, compared to controls.