Jodie A. McClelland

Knee kinetics during walking at different speeds in people who have undergone total knee replacement

Previous research suggests that most people who have undergone total knee replacement (TKR) walk with a sagittal knee moment profile and peak knee moments that are different from normal. However, most previous research has consisted of small samples of patients with prostheses that are no longer in use. The aim of this study was to compare the peak knee moments and patterns of the moment waveforms of walking at different speeds between a large cohort of TKR patients with the Genesis-II PS prosthesis (Smith and Nephew, Memphis, USA) and matched control participants. Forty patients 12months following TKR and 40 control participants were assessed during walking at self-selected comfortable and fast speeds using motion analysis. Individual sagittal plane knee moment graphs were assessed for the presence of a biphasic pattern. Peak sagittal and coronal plane knee moments were compared between groups using a univariate ANOVA with walking speed as a covariate. A biphasic moment pattern was present in 87% and 92% of TKR patients when walking at comfortable and fast speeds, respectively. The knee flexor (p<0.001 at both speeds), extensor (p=0.004 at comfortable speed and p<0.001 at fast speed) and adductor (p<0.001 at both speeds) moments were reduced in the TKR patients. The high proportion of TKR patients with biphasic moment patterns was unexpected, but suggests that modern prostheses can result in more normal outcomes. Nonetheless, the peak knee moments of patients were reduced compared to controls. Although these reductions may be beneficial to the survival of the prosthesis, these abnormalities may also indicate suboptimal functional outcome from TKR.

Gender differences in the knee adduction moment after anterior cruciate ligament reconstruction surgery

Background The external knee adduction moment during gait has previously been associated with knee pain and osteoarthritis (OA). Recently, the knee adduction moment has been shown to be increased following anterior cruciate ligament (ACL) reconstruction surgery and has been suggested as a potential mechanism for the progression of early onset knee OA in this population. No study has investigated the gender differences in gait biomechanics following ACL reconstruction. Aim To examine gender differences in gait biomechanics following ACL reconstruction surgery. Methods 36 subjects (18 females, 18 males) who had previously undergone ACL reconstruction surgery (mean time since surgery 20 months) underwent gait analysis at a self-selected walking speed. Males and females were well matched for age, time since surgery and walking speed. Maximum flexion and adduction angles and moments were recorded during the stance phase of level walking and compared between the male and female groups. Results The knee adduction moment was 23% greater in the female compared with the male ACL group. No gender differences were seen in the sagittal plane. No differences were seen between the reconstructed and contralateral limb. Conclusion The higher knee adduction moment seen in females compared with males may suggest an increased risk for the development of OA in ACL-reconstructed females.

Lower limb strength following total knee arthroplasty: A systematic review

BACKGROUND Total knee arthroplasty (TKA) is commonly performed for end-stage knee osteoarthritis to relieve pain and improve quality of life. Understanding specific muscle weakness following TKA is required in order to develop targeted rehabilitation programmes for TKA patients. The aim of this systematic review was to determine whether TKA patients have reduced strength in lower limb muscle groups compared to controls. METHODS A search of common scientific databases was conducted. A modified published checklist was used to assess the risk of bias. A meta-analysis was completed for each lower limb muscle group in three separate post-operative time periods (4-6 months, 1-3 years, and >3 years). The GRADE approach was used to determine the quality of the evidence. RESULTS Fifteen studies met the inclusion criteria for this review. There was low quality evidence for all meta-analyses. The meta-analyses showed that TKA patients had weaker quadriceps than the controls at every post-operative time (pooled effect sizes between -2.81 and -0.53). The meta-analyses of hamstring strength for patients 1-3 years post-operatively also showed patient weakness (pooled effect size=-1.87) and no significant difference at >3 years post-operatively (pooled effect size=-0.20). CONCLUSION There was low quality evidence of quadriceps and hamstring weakness following TKA. Further research is required to determine if other lower limb muscles also display similar muscle weakness. Strategies that specifically target strengthening of these muscle groups may need to be incorporated in rehabilitation to improve outcomes from TKA. LEVEL OF EVIDENCE I.

Effect of Fatigue on Landing Biomechanics after Anterior Cruciate Ligament Reconstruction Surgery

PURPOSE The purpose of this study was to determine the effects of fatigue on lower limb biomechanics during landing in patients who had undergone anterior cruciate ligament (ACL) reconstruction surgery. METHODS Fifteen male participants who had undergone primary ACL reconstruction 15-19 months previously and 11 uninjured male control subjects had three-dimensional lower limb kinematics and kinetics quantified during single-limb landings, both before and during progression to fatigue. The single-limb landings were a vertical drop from a 30-cm platform, and subjects performed repetitive bilateral squats to induce fatigue. RESULTS Fatigue led to reduced flexion in the lower limb, increased hip and knee abduction, increased knee rotation, and reduced knee joint moments. The response to fatigue was similar between the ACL-reconstructed limb and the control group as well as the reconstructed limb and the contralateral limb. The only kinematic variable to show a between-group or between-limb difference was hip flexion at initial contact, whereby flexion was greater for the reconstructed side. Although knee flexion and adduction moments were smaller for the reconstructed knee compared with the contralateral knee, they were not different from the control group. CONCLUSIONS The results show that having an ACL reconstruction does not necessarily mean greater vulnerability to the effect of fatigue during single-limb landing. Nonetheless, some of the landing positions that were observed with fatigue potentially compromise the knee and integrity of the ACL graft.

Hamstring tendon anterior cruciate ligament reconstruction: does gracilis tendon harvest matter?

PurposeHamstring tendon grafts are a popular choice for anterior cruciate ligament (ACL) reconstruction. Typical morbidity reported after hamstring tendon harvest is muscle weakness in flexion, and whilst still a matter for debate, this morbidity may be greater if the gracilis tendon is harvested in addition to the semitendinosus.This study sought to comprehensively compare the outcome of ACL reconstructions in which the semitendinosus was harvested alone (ST group) or with the gracilis (ST/G group).MethodsTwenty patients (ten ST, ten ST/G) were assessed with a variety of measures that included subjective scores, function, strength and tibial rotation as measured by gait analysis during a pivoting task.ResultsResults showed that the graft diameter was significantly larger in the ST group, but there were no other differences between the groups for any other outcome measure.ConclusionHarvesting the gracilis in addition to semitendinosus does not appear to affect either the outcome or graft-related morbidity after hamstring ACL reconstruction.

Three dimensional motion analysis of within and between day repeatability of tibial rotation during pivoting.

Activities that involve a change in direction apply a high rotational load to the knee joint. Biomechanical analysis of such activities may be useful for determining mechanisms that underlie knee injury and the success of ligament reconstruction surgery. However, the reliability of the measurement of tibial rotation remains unclear. The purpose of this study was to determine the reliability of tibial rotation measurements during a pivoting task, both between testing sessions conducted on the same day and between those made one week apart. Three-dimensional motion analysis was used to measure peak internal tibial rotation and rotational excursion during a stair descent and pivoting task in eleven healthy subjects (six female, five males). Intraclass correlation coefficients (ICC (3, 1)) and typical error analyses were used to examine within and between day reliability. Tibial rotational excursion had excellent reliability for within day (ICC=0.82) and between day sessions (ICC=0.76) whereas peak internal rotation had good reliability (within ICC=0.74; between ICC=0.68). Typical error was less than 2.4 degrees for within day measures and 2.9 degrees for between day measures. It was concluded that tibial rotation can be measured reliably during pivoting. Typical error values were less than the usual group differences in rotational excursion reported in the literature. The ability to reliably quantify tibial rotation during dynamic activities is important in determining the causes of persisting instability following anterior cruciate ligament reconstruction.

Does Quadriceps Atrophy Exist in Individuals With Patellofemoral Pain? A Systematic Literature Review With Meta-analysis

STUDY DESIGN Systematic literature review. OBJECTIVES To investigate whether quadriceps atrophy is present in the affected limb of individuals with patellofemoral pain (PFP). BACKGROUND PFP is a common condition. Atrophy of the quadriceps femoris, in particular the vastus medialis obliquus, is often assumed to be present by clinicians, and its resolution may underpin the reported effectiveness of quadriceps strengthening intervention in PFP rehabilitation. METHODS A systematic search of the literature was conducted to identify studies that measured the size of the quadriceps in individuals with PFP. Meta-analyses were performed to determine whether quadriceps size in limbs with PFP differed from that in comparison limbs. Separate meta-analyses were performed for quadriceps size measured as girth and quadriceps size measured with imaging (thickness, cross-sectional area, and volume). RESULTS Ten studies were included in this review. The meta-analysis of girth measurements (3 studies) found no atrophy in limbs with PFP (P = .638). The meta-analyses for imaging techniques (thickness, cross-sectional area, or volume measurements) showed atrophy in the limb with PFP compared to both the asymptomatic limb (3 studies) (P = .036) and limbs from a comparison group (3 studies) (P = .001). The single study that compared the vastus medialis obliquus and vastus lateralis in individuals with PFP found atrophy of both the vastus medialis obliquus and vastus lateralis but no significant difference in the amount of atrophy between them (P = .179). CONCLUSION Quadriceps muscle atrophy was shown to be present in PFP when analyzed by imaging, but not by girth measures. Insufficient data were available to determine if there was greater atrophy of the vastus medialis obliquus than the vastus lateralis. These findings support the rationale for use of quadriceps strengthening as part of a rehabilitation program for PFP.

Alternative modelling procedures for pelvic marker occlusion during motion analysis.

BACKGROUND Motion analysis of participants with different body shapes under diverse conditions can be problematic when vital markers are occluded. The markers located over the anterior superior iliac spines are commonly occluded in older patients and during analysis of activities with trunk and hip flexion which can prevent accurate calculation of lower limb joint kinematics. Options to modify standard body models exist but have not been described in detail, and the effects on the lower limb kinematics are not known. METHODS Three-dimensional motion analysis data were collected from 10 participants during level walking. A single trial from each participant was processed using the standard PlugIn Gait model and with four alternative modelling procedures where either one or both anterior pelvis markers were not labelled for all or part of the trial. Similarity of these alternative procedures to PlugIn Gait was assessed by comparison of peak kinematic characteristics and Root Mean Square (RMS) across the gait cycle. FINDINGS The peak lower limb kinematics of all four alternative modelling procedures were similar to PlugIn Gait to within 4.57 degrees . The alternative procedure most similar to PlugIn Gait was less than 1.24 degrees different. The largest RMS was 2.88 degrees and the smallest was 0.92 degrees . INTERPRETATION This study has presented several options for researchers and clinicians to modify the standard body models of motion analysis so that lower limb kinematics may be calculated without reliance on continuous visualisation of anterior pelvic markers. Although the alternative modelling processes are subject to different sources of error which need to be considered, the error is minimal.

Can ultrasound measurements of muscle thickness be used to measure the size of individual quadriceps muscles in people with patellofemoral pain

OBJECTIVES Selective atrophy of vastus medialis oblique (VMO) may be present in patellofemoral pain (PFP). This study investigated the validity of real-time ultrasound in measuring the thickness of each quadriceps muscle. DESIGN Cross sectional-Validity. SETTING University laboratory. PARTICIPANTS 10 limbs, 5 people with unilateral PFP. MAIN OUTCOME MEASURES The thickness of VMO, vastus lateralis (VL), vastus intermedius (VI), rectus femoris (RF), and vastus medialis (VM) measured with ultrasound were compared to magnetic resonance imaging (MRI) muscle thickness measurements, using Pearsons (r), and compared to MRI muscle cross-sectional area (CSA) measurements, using Spearmans correlation coefficient (rho). RESULTS There was a good correlation between ultrasound and MRI measures of the thickness of each superficial quadriceps muscle VMO (r = 0.86), VM (r = 0.86), VL (r = 0.94), RF (r = 0.86), and a poor for VI (r = 0.37). Ultrasound measures had a good correlation to MRI muscle CSA measures for VL (rho = 0.83) and RF (rho = 0.88), moderate for VM (rho = 0.73), and poor for VMO (rho = 0.20), and VI (rho = 0.310). CONCLUSION Real-time ultrasound muscle thickness measurements are correlated to MRI measured thickness of superficial quadriceps muscles (VMO, VL, VL, and RF) in PFP.

Patterns in the knee flexion-extension moment profile during stair ascent and descent in patients with total knee arthroplasty

The aim of this study was to investigate the prevalence of abnormal knee biomechanical patterns in 40 patients with a modern TKA prosthesis, compared to 40 matched control participants when ascending and descending stairs. Fewer patients were able to ascend (65%) or descend stairs (53%) unassisted than controls (83%). Of the participants who could ascend and descend, cluster analysis classified most patients (up to 77%) as demonstrating a similar knee moment pattern as all controls. A small subgroup of patients who completed the tasks did so with distinctly abnormal biomechanics compared to other patients and controls. These findings suggest that recovery of normal stair climbing is possible. However, rehabilitation might be more effective if it were tailored to account for these differences between patients.