Aims. The standard of surgical treatment for lower limb neoplasms had been characterized by highly interventional techniques, leading to severe kinetic impairment of the patients and incidences of phantom pain. Rotationplasty had arisen as a potent limb salvage treatment option for young cancer patients with lower limb bone tumours, but its impact on the gait through comparative studies still remains unclear several years after the introduction of the procedure. The aim of this study is to assess the effect of rotationplasty on gait parameters measured by gait analysis compared to healthy individuals. Methods. The MEDLINE, Scopus, and Cochrane databases were systematically searched without time restriction until 10 January 2022 for eligible studies. Gait parameters measured by gait analysis were the outcomes of interest. Results. Three studies were eligible for analyses. Compared to healthy individuals, rotationplasty significantly decreased gait velocity (-1.45 cm/sec; 95% confidence interval (CI) -1.98 to -0.93; p < 0.001), stride length (-1.20 cm; 95% CI -2.31 to -0.09; p < 0.001), cadence (-0.83 stride/min; 95% (CI -1.29 to -0.36; p < 0.001), and non-significantly increased cycle time (0.54 sec; 95% CI -0.42 to 1.51; p = 0.184). Conclusion. Rotationplasty is a valid option for the management of lower limb bone tumours in young cancer patients. Larger studies, with high patient accrual, refined surgical techniques, and well planned rehabilitation strategies, are required to further improve the reported outcomes of this procedure. Cite this article: Bone Jt Open 2023;4(11):817–824

Gait analysis is an indispensable tool for scientific assessment and treatment of individuals whose ability to walk is impaired. The high cost of installation and operation are a major limitation for wide-spread use in clinical routine. Advances in Artificial Intelligence (AI) could significantly reduce the required instrumentation. A mobile phone could be all equipment necessary for 3D gait analysis. MediaPipe Pose provided by Google Research is such a Machine Learning approach for human body tracking from monocular RGB video frames that is detecting 3D-landmarks of the human body. Aim of this study was to analyze the accuracy of gait phase detection based on the joint landmarks identified by the AI system. Motion data from 10 healthy volunteers walking on a treadmill with a fixed speed of 4.5km/h (Callis, Sprintex, Germany) was sampled with a mobile phone (iPhone SE 2nd Generation, Apple). The video was processed with Mediapipe Pose (Version 0.9.1.0) using custom python software. Gait phases (Initial Contact - IC and Toe Off - TO) were detected from the angular velocities of the lower legs. For the determination of ground truth, the movement was simultaneously recorded with the AS-200 System (LaiTronic GmbH, Innsbruck, Austria). The number of detected strides, the error in IC detection and stance phase duration was calculated. In total, 1692 strides were detected from the reference system during the trials from which the AI-system identified 679 strides. The absolute mean error (AME) in IC detection was 39.3 ± 36.6 ms while the AME for stance duration was 187.6 ± 140 ms. Landmark detection is a challenging task for the AI-system as can clearly be seen be the rate of only 40% detected strides. As mentioned by Fadillioglu et al., error in TO-detection is higher than in IC-detection

The Step Holter is a software and mobile application that can be used to easily study gait analysis. The application can be downloaded for free on the App Store and Google Play Store for iOS and Android devices. The software can detect with an easy calibration the three planes to detect the movement of the gait. Before proceeding with the calibration, the smartphone can be placed and fixed with a band or stowed into a long sock with its top edge at the height of the joint line, in the medial side of the tibia. The calibration consists in bending the knee about 20 to 30 degrees and then making a rotation movement, leaving the heel fixed to the ground as a rotation fulcrum. After calibration, the program records data related to lateral flexion, rotation, and bending of the leg. This data can be viewed directly from the smartphone screen or transmitted via a web link to the Step Holter web page . www.stepholter.com. by scanning a personal QR code. The web page allows the users to monitor the test during its execution or view data for tests done previously. By pressing the play button, it is possible to see a simulation of the patient's leg and its movement. With the analyze button, the program is capable of calculating the swing and stance phase of every single step, providing a plot with time and percentages. Finally, with the Get Excel button, test data can be conveniently exported for more in-depth research. The advantage of this application is not only to reduce the costs of a machine for the study of gait analysis but also being able to perform tests quickly, without expensive hardware or software and be used in specific spaces, without specialized personnel. Furthermore, the application can collect important data concerning rotation that cannot be highlighted with the classic gait analysis. The versatility of a smartphone allows tests to be carried out not only during walking but also by climbing or descending stairs or sitting down or getting up from a chair. This software offers the possibility to easily study any kind of patients; Older patients, reluctant to leave their homes for a gait analysis can be tested at home or during an office control visit. Step Holter could be one small step for patients, one giant leap for gait study simplicity. For any figures or tables, please contact authors directly

Total knee replacement in a commonly performed procedure in the United Kingdom with more than 76000 primary procedures performed in 2010. With so many procedures performed there has to be a robust way of assessing the outcome of the procedure. Gait analysis is a valuable tool in objectively assessing the these patients. Inertial movement units (IMU's) are a fairly new development in gait analysis. The aim of our project is to use IMUs to assess the differences in gait profile between a cohort of healthy controls, a group of pre operative knee replacement patients, a group of 8 week post operative patients and finally a group of post operative knee replacement patients at 1 year. We studied a total of 47 patients. We also had data from a previous study done on healthy controls using the same measurement tool. We measured three parameters: peak swing phase flexion, peak stance phase flexion and stride duration. Our findings indicate that pre-operative patients have a significantly reduced peak flexion in swing and stance with increased stride duration. This shows no improvement at the 8 week mark. At the 1 year mark peak flexion in swing returns to pre operative levels but flexion in stance and stride duration are still poor. These findings may not have been identified without gait analysis. Gait analysis using intertial movement units will add much information to radiographs and clinical examination. This information can also be used to tailor individual patients rehabilitation

Introduction: It has been proposed that rotational gait abnormalities in the normal child are usually reflections of the anatomic deformity. A decreased acetabular and femoral anteversion have been recognized as a predisposing factor for osteoarthritis of the hip and the McKibbin instability index was introduced to quantify this relationship. Additionally, an increased femoral anteversion has been associated with osteoarthritis of the knee. However, it is well known that compensatory factors influence the dynamic rotational profile during gait. We compared rotational computed tomography data with gait analysis to evaluate their correlation and to elucidate the influence of compensatory mechanisms. Materials and Methods: In a prospective study conducted between 2001 and 2005 patients presenting with rotational malalignment were sent for 3D gait analysis. Main exclusion criterion was any kind of neurological affection. Patients in whom surgery was considered were referred to rotational computed tomography. The rotational alignment of the pelvis, hip and knee at different times during the gait cycle as evaluated in the 3D gait analysis was compared to the angular values derived from the rotational computed tomography for the femur and tibia and statistically analyzed and correlated. Results: There were 12 female and 16 male patients with a mean age of 16 (± 9.7) years at the time of gait analysis. After a first evaluation of data 8 limb segments were excluded to increase the quality of data. The mean anteversion of the femur was 29 degrees (2 degrees of retrotorsion to 56 degrees of anteversion) and the mean tibial torsion was 31 degrees (1 to 66 degrees of external torsion). The calculation of the Pearson correlation showed that an increase of femoral anteversion resulted in an increase of pelvic range of motion. An increase of femoral anteversion resulted in an increase of the internal rotation of the hip. Highly significant correlations were found between the rotational–CT values for the tibia and the all parameters describing rotation of the knee. The determination coefficient was high for tibial torsion versus knee rotation (R2 = 0.64), but showed a low value for femoral anteversion versus hip rotation (R2 = 0.2). Conclusion: The rotation of the hip as found in the gait analysis showed only weak correlation with rotational CT data. This is not surprising as the hips segment offers many possibilities for compensation. The torsion of the tibia was found to correlate very strongly with the gait analysis. The McKibbin index seems questionable as a prognostic factor for the individual patient in the light of a multitude of dynamic compensatory influences. Effort should be made to integrate the static instability index with dynamic gait analysis data

Patellofemoral osteoarthritis (PFOA) affects 32% men and 36% women over the age of 60years and is associated with anterior knee pain, stiffness, and poor mobility. Patellofemoral arthroplasty (PFA) is a bone-sparing treatment for isolated PFOA. This study set out to investigate the relationship between patient-related outcome measures (PROMs) and measurements obtained from gait analysis before and after PFA. There are currently no studies relating to gait analysis and PFA available in the literature. A prospective cohort study was conducted of ten patients known to have isolated PFOA who had undergone PFA compared to a gender and age matched control group. The patients were also asked to complete questionnaires (Oxford knee score (OKS), EQ-5D-5L) before surgery and one year after surgery. Gait analysis was done on an instrumented treadmill comparing Ground reaction force parameters between the control and pre and post-operative PFA patients. The average age 60 (49–69) years with a female to male ratio of 9:1. Patient and healthy subjects were matched for age and gender, with no significant difference in BMI. Post-op PFA improvement in gait seen in ground reaction force at 6.5km/h. Base support difference was statistically significant both on the flat P=0.0001 and uphill P=0.429 (5% inclination) and P=0.0062 (10% inclination). PROMS response rate was 70%(7/10) pre-operative and 60%(6/10) post-operative. EQ-5D-5L scores reflected patient health state was better post-operatively. This study found that gait analysis provides an objective measure of functional gait and reflected by significant quality-of-life improvement of patients post PFA. Literature lacks studies relating to gait-analysis and PFA. Valuable information provided by this study highlights that PFA has a beneficial outcome reflected by PROMs and improvement in vertical ground reaction force and gait. Further research is needed to assess how care-providers may use gait-analysis as part of patient care plans for PFOA patients

Total hip arthroplasty (THA) is one of the most successful surgery. However, patients' expectations have increased over the last two decades in regards to hip function after joint replacement, the patients assume to return their daily and sport activities without major limitations. This presentation will examine the effect of surgical approaches and implant designs as well as rehabilitation protocol on the clinical and biomechanical outcomes after THA. The new implant designs for THA aim to improve joint function whereas the surgical approaches intend to reduce muscle damage to regain muscle strength. One important determinant measured from gait analysis is the hip abduction moment as the abductors play a key role in stabilizing the pelvis in the frontal plane, particularly in phases of transition, such as the single leg stance in walking or stair climbing. This showed that muscle strength needs to be preserved. To minimize the risk of hip joint instability, a strong focus of implant development has been carried out. To illustrate this important concept within the context of gait analysis, I will present two studies that examine the influence of surgical approach and biomechanical reconstruction; and the second, is a prospective RCT comparing a dual mobility implant to a standard total hip replacement

Total Knee Arthroplasty (TKA) has been widely performed and successful clinical outcomes have been achieved for the patients with knee osteoarthritis which is generally known to cause ADL problem. Clinical and radiographic evaluations are commonly used when evaluating postoperative outcomes, among which kinetic analysis and gait analysis are considered essential to investigate the more detailed effect of the treatment. There is a controversy whether performing TKA on both knees simultaneously is appropriate in treating patients with bilateral knee osteoarthritis, in terms of the speed and effectiveness of gait recovery. In this study, we reviewed the significance of performing simultaneous bilateral TKA, by the results of preoperative and postoperative gait analysis. Materials and Methods: Total of eight patients, all female and diagnosed of bilateral knee osteoarthritis, were treated with TKA and reviewed. Mean age was 70 years old (60–74). For prosthesis, we used Scorpio NRG PS, and ADVANCE, with cementation for all. No patella was replaced. Some had unilateral TKA, and some were treated bilaterally as needed. We examined distance factors (step length and step width), gait velocity, and gait barycentric factors (single-support phase and Ratio of center of gravity maximum values). We performed the analysis preoperatively, postoperatively at 1 month, 3 months, and 6 months. We used the floor pressure gauge (NITTA CORPORATION) and the three-dimensional motion analysis device (DITECT Co. Ltd) for the analysis. Results: During the six-month follow-ups, six cases were unilateral TKA and two were treated bilaterally. Increase in step length was seen in the unilateral cases, and it decreased in the bilateral cases. Step width decreased in five cases, two cases showed no change, and increased in one case. Gait velocity had increased in all cases. Single-support phase was close to 1 for all the cases. Ratio of center of gravity maximum values, which indicates the movement of centroid during ambulation, the ratio went up for unilateral cases while it showed no change in the bilateral cases. Discussion: Quantitative studies of gait analysis have reported that gait condition had improved after TKA. However, some reported that the gait impairment had remained. Unilateral TKA group showed gait restoration, whereas gait abnormality in either leg was seen in the bilateral group. Gait analysis is effective in determining whether surgeons should perform unilateral TKA or bilateral TKA to the patients with bilateral knee osteoarthritis. Among the gait analysis factors, we consider that Ratio of center of gravity maximum values shows effectively the improvement of the treated knee, gait, and the condition of contralateral knee

Purpose. This study aimed to objectively define gait derangements and changes before and after Tibialis Anterior Tendon Transfer surgery in a group of patients treated using the Ponseti method. Methods. 21 feet in 13 patients with Ponseti treated clubfoot who showed supination in swing on clinical examination, underwent gait analysis before, and approximately 12 months after, Tibialis Anterior Tendon transfer. 3–4 weekly casts were applied prior to the surgery, which was performed by transfer of the complete TA tendon to the lateral cuneiform. A parental satisfaction questionnaire was also completed. Results. In all but one patient, increased supination in swing phase was confirmed on pre-operative gait analysis, with EMG evidence of poor Tibialis Anterior modulation through-out the gait cycle. Post-operatively all patients showed improved positioning at initial contact, with heel strike and an absence of supination, and a decrease in swing phase supination. In all patients, knees were overly flexed at initial contact, some continuing through stance phase; there was no change seen postoperatively. All parents reported marked improvements in gait and activity level post-operatively. Conclusion. Gait analysis can be useful to confirm the need for tibialis anterior tendon transfer. Improved post-operative gait patterns seen by parents and clinicians can be related to objective improvements seen during gait analysis, confirming the benefit of tibialis anterior tendon transfer in appropriate patients

Instrumented gait analysis has evolved into a widely used tool to define and describe abnormalities of gait. It is used as a tool to enhance the performance in sports as well as to measure the effects of conservative or surgical treatment methods. Patients usually walk very slow during gait training, whereas normal data are obtained at regular walking velocity. This may lead to misinterpretations. The purpose of this study was to determine the effects of walking slow towards gait and to establish normal data for “walking slow” on a treadmill. 10 healthy volunteers with no known gait problem underwent training to accommodate to the conditions of treadmill walking. There were 5 females and 5 males. The mean age was 30 [range 22–56] years. Instrumented gait analysis was performed using a camera system (Motion Analysis Systems). Data obtained were processed by OrthotracTM and the proprietary software of our lab. During data acquisition participants were asked to walk at leisure velocity, then they were asked to slow down as much as possible. The normal walking velocity of was 0,99 [range 0,78–1,16] m/s. When asked to walk as slow as possible the walking speed decreased to 0,29 [range 0,14–0,50] m/s. We noted a change in the ratio between swing and stance periods with less swing time, as well as a increase of double limb support time. Step length decreased. Changes in the pattern of motion included delayed and increased peak ankle dorsiflexion and decrease of ankle plantar flexion at initial contact. 3-D motion data for hip and knee also demonstrate noteworthy changes, generally resulting in a decrease of joint excursion. Interpretation of gait data obtained from slow walking patients should consider the effects walking velocity. Locomotion therapy (e.g. for spinal cord injuries) should not force patients into motion patterns that are only found at faster walking velocities

Introduction. Total hip arthroplasty (THA) is the most effective treatment modality for severe arthritis of the hip. Patients report excellent clinical and functional outcomes following THA, including subjective improvement in gait mechanics. However, few studies in the literature have outlined the impact of THA, as well as surgical approach, on gait kinetics and kinematics. Purpose. The purpose of this study was to determine the impact of surgical approach for THA on quantitative gait analysis. Methods. Thirty patients undergoing THA for primary osteoarthritis of the hip were assigned to one of three surgical approaches (10 anterior, 10 posterior, and 10 lateral). A single surgeon performed each individual approach. Each patient received standardized implants at the time of surgery (cementless stem and acetabular component, cobalt chrome femoral head, highly cross-linked liner). Patients underwent 3D gait analysis pre-operatively, and at 6- and 12-weeks following the procedure. At each time point, temporal gait parameters, kinetics, and kinematics were compared. Statistical analysis was performed using one-way analysis of variance. Results. All three groups were similar with respect to age (p=0.27), body mass index (p=0.16), and the Charlson Comorbidity Index (p=0.66). Temporal parameters including step length, stride length, gait velocity, and percent stance and swing phase were similar between the groups at all time points. The lateral cohort had higher pelvic tilt during stance on the affected leg than the anterior cohort at 6-weeks (p=0.033). Affected leg ipsilateral trunk lean during stance was higher in the lateral group at 6-weeks (p=0.006) and 12-weeks (p=0.037) compared to the other cohorts. The anterior and posterior groups demonstrated an increased external rotation moment at 6-weeks (p=0.001) and 12-weeks (p=0.005) compared to the lateral group. Discussion. Although temporal parameters were similar across all groups, some differences in gait kinematics and kinetics exist following THA using different surgical approaches. However, the clinical relevance based on the small magnitude of the differences remains in question

Total hip arthroplasty (THA) is the most effective treatment modality for severe arthritis of the hip. Patients report excellent clinical and functional outcomes following THA, including subjective improvement in gait mechanics. However, few studies in the literature have outlined the impact of surgical approach on gait kinetics and kinematics. The purpose of this study was to determine the impact of surgical approach for THA on quantitative gait analysis. Thirty patients undergoing THA for primary osteoarthritis of the hip were assigned to one of three surgical approaches (10 anterior, 10 posterior, and 10 lateral). A single surgeon performed each individual approach. Each patient received standardised implants at the time of surgery (cementless stem and acetabular component, cobalt chrome femoral head, highly cross-linked liner). Patients underwent 3D gait analysis pre-operatively, and at 6- and 12-weeks following the procedure. At each time point, temporal gait parameters, kinetics, and kinematics were compared. Statistical analysis was performed using one-way analysis of variance. All three groups were similar with respect to age (p=0.27), body mass index (p=0.16), and the Charlson Comorbidity Index (p=0.66). Temporal parameters including step length, stride length, gait velocity, and percent stance and swing phase were similar between the groups at all time points. The lateral cohort had higher pelvic tilt during stance on the affected leg than the anterior cohort at 6-weeks (p=0.033). Affected leg ipsilateral trunk lean during stance was higher in the lateral group at 6-weeks (p=0.006) and 12-weeks (p=0.037) compared to the other cohorts. The anterior and posterior groups demonstrated an increased external rotation moment at 6-weeks (p=0.001) and 12-weeks (p=0.005) compared to the lateral group. Although temporal parameters were similar across all groups, some differences in gait kinematics and kinetics exist following THA using different surgical approaches. However, the clinical relevance based on the small magnitude of the differences remains in question

Background. The aim of this study is to analysis the ability of these patients, treated with MOMHR, to resume sport activities by gait analysis and clinical evaluations. Metal on metal hip resurfacing (MOMHR) is indicated to treat symptomatic hip osteoarthritis in young active patients. These patients require a high level of function and desire to resume sport activities after surgery. Study Design & Methods. 30 consecutive male patients playing high impact sports with unilateral hip osteoarthritis and normal contralateral hip were included in the study, they were treated with MOMHR by the same surgeon. No patients were lost to follow. The mean age at operation was 39.1 years (range 31 to 46). Primary diagnosis was osteoarthritis. OHS, HHS, UCLA activity score were completed at pre-operative time, six months and one year after surgery. Functionally, gait analysis was performed in all patients 6 months and one year after surgery. A stereophotogrammetric system (Smart-DX, BTS, Milano, Italy, 10 cameras, 250Hz) and two platforms (9286BA Kistler Instrumente AG, Switzerland) were used. Cluster of 4 markers were attached on the skin of each bone segment, a number of anatomical landmarks were calibrated and segment anatomical frames defined, markers were positioned by the same operator. Walking, running and squat jump were analyzed and strength and range of movement of the hips and knees were calculated. Results. At follow-up times the survival rate for the whole cohort was 100%. The mean pre-op OHS was 28.1 points (range 15.0 to 38.0), at 6 months after surgery was 44.5 points (range 44 to 48), at one year after surgery was 47.9 points (range 45 to 48). The mean pre-op HHS was 54.7 points (range 33.1 to 73.4), at 6 months after surgery was 96.7 points (range 93.4 to 100), at one year after surgery was 99.7 points (range 95.7 to 100). The mean pre-op UCLA activity score was 2.7 (range 2 to 4), at 6 months after surgery was 7.4 (range 5 to 10), at one year after surgery was 8.6 (range 7 to 10). At 6 months after surgery, patients showed a reduction of the differences between the operated and the contralateral side during walking, running and squat jumping. (p<0.01). One year after the operation there were no differences. At 3 months after surgery the mean hip flexion extension range of motion was in the normal hips 41±1.7 and in the operated hips 37.3±2.1; at 6 months after surgery the mean hip flexion extension range of motion was in the normal hips 45.4±1.8 and in the operated hips 42.0±1.7; At 1 year after surgery the hip flexion extension range of motion was in the normal hips 42.9±1.7 and in the operated hips 45.5±1.4. (p=0.001). Conclusions. Our gait analysis study shows that the biomechanical function of the operated hip is completely recovered 1 year after MOMHR operation. As a consequence sport activities can be successfully resumed. MOMHR is a good choice for young and active patients affected by hip osteoarthritis requiring a high level of activity

Introduction:. There is paucity of literature on Gait analysis following Total Ankle Replacement (TAR). We aimed to study changes to gait after successful Mobility TAR. Methods:. 20 patients who underwent a primary TAR, with a diagnosis of either OA or PTOA were recruited between October 2008 and March 2011. Gait analysis was carried out using the Helen Hayes marker system with VICON 3D opto-electric system pre-operatively, 3, 6 and 12 months post-operatively. Ankle kinematics and spatio-temporal parameters of gait were studied. Results:. 20 patients were included. Mean age was 63.6 years (Range 43–84), mean BMI was 29.6 ± 4.08. Diagnosis was OA in 12 (52.2%) and PTOA in 8 (34.8%). Results showed increase in average and maximum range of dorsiflexion from (3° to 7°) and (11° to 17°) respectively from pre-op to 1 year, but statistically not significant (p>0.05). Of the temporal variables, Average Cadence increased from Pre-op to 1 year (102 to 106 steps/min); double support (0.35% to 0.31%), single support (0.41% to 0.39%) and toe off point at gait cycle (63.9% to 62.4%) decreased from pre-op to 1 year, but failed to achieve statistical significance (p>0.05). For distance variables, Step length showed a significant increase from pre-op to 1 year (0.21m/s to 0.58m/s; p<0.001); stride length increased (1.05m/s to 1.13m/s), step time and stride time decreased (0.60 secs to 0.58 secs) and (1.19 to 1.14 secs) respectively and Walking speed increased (0.90m/s to 1.00m/s) from pre-op to 1 year, but statistically not significant (P>0.05). Conclusion:. There was significant improvement in step length after TAR from pre-op to 1 year. Although the results showed a trend for improvement in average dorsiflexion, average cadence, stride length, walking speed, decreased step and stride length times, which showed improvement in walking pattern in these group of patients, but failed to achieve statistical significance

Introduction. Various rehabilitation shoes are prescribed to protect the forefoot following surgery. Patients often complain of discomfort in other areas as a result of the postoperative shoe, including the knee, hip and lower back. This has never been quantified. This study aims to establish the effect on other joints using gait analysis. Methods: 11 healthy volunteers were investigated using various common types of postoperative shoe. They were studied with gait analysis equipment and the joint motion assessed with commercial software. The effect of commercial devices designed to minimise gait changes by lifting the contralateral foot were also evaluated. Results. There was a reduction in knee flexion and extension compared to the contralateral leg in all phases of the gait cycle. This was the case with both heel wedge shoes and inflatable air boots. There was also an increase in pelvic tilt during gait with both shoes, which was more pronounced with the air boot. The foot raise device for the contralateral foot which is designed to decrease these changes was effective in decreasing gait changes. Discussion. The use of rehabilitation shoes after forefoot surgery is almost universal. Patients are rarely counselled of the risk of joint pain or back pain as a result of the postoperative shoe. Patients with pre-existing back pain or hip pain may have fewer symptoms if they are supplied with an equalising device to raise the other foot. Conclusions. Patients are at risk of initiation or exacerbation of low back pain or lower limb joint pain from the use of postoperative shoes. Patients with a history of back or limb symptoms should be provided with an equalising device for the contralateral limb to minimise their discomfort. Patients should be warned of this risk when giving consent

We studied the kinematic patterns of knee, performing gait analysis, in diplegic children. Our gait laboratory consists of 4 infrared cameras. We used the Elite program. We studied initially 25 normal children. We constructed our models and developed the linear measurements of the gait. Then we performed measurements of the angles of the knee and ankle joints and the wave forms of the kinematic forms of these joints. We performed gait analysis in 25 diplegic children aged 4–15 years old. We found two groups of children. In the first group (21 children) the main lesion was in the kinematics of the knee and in the second group (4 children) in the ankle joint. In the first group, characteristic pattern is the absence of full extension of the knee during stance. Analyzing the kinematics of the ankle joint of this group, we found 12 children with toe strike and 9 children landing in the whole foot. Studding the wave form of the knee in stance and swing, we separated those with spasticity alone from those with fixed contractures of the knee. Our patients were treated either with botulinum injections or with intamuscular lengthening, according to our results. In the second group, of diplegic children with toe walking, we found increased equinus, both in stance and swing. Kinematic studies of the knee in frontal and coronal level showed increased adduction of the femur( scissoring) and increased anteversion. Gait analysis in diplegic children offers an accurate assessment of the gait disorders. We can plan our treatment according the results of the gait analysis

Background: Mobile-bearing knee replacements have some theoretical advantages over fixed-bearing devices. However, very few randomized controlled clinical trials have been published to date, and studies showed little clinical and subjective advantages for the mobile-bearing using traditional systems of scoring. The choice of the ideal outcome measure to assess total joint replacement remains a complex issue. However, gait analysis provides objective and quantifying evidences of treatment evaluation. Significant methodological advances are currently made in gait analysis laboratories and ambulatory gait devices are now available. The goal of this study was to provide gait parameters as a new objective method to assess total knee arthroplasty outcome between patients with fixed- and mobile-bearing, using an ambulatory device with minimal sensor configuration. This randomized controlled double-blind study included to date 14 patients: the gait signatures of four patients with mobile-bearing were compared to the gait signatures of nine patients with fixed-bearing pre-operatively and post-operatively at 6 weeks, 3 months and 6 months. Each participant was asked to perform two walking trials of 30m long at his/her preferred speed and to complete a EQ-5D questionnaire, a WOMAC and Knee Society Score (KSS). Lower limbs rotations were measured by four miniature angular rate sensors mounted respectively, on each shank and thigh. A new method for a portable system for gait analysis has been developed with very encouraging results regarding the objective outcome of total knee arthroplasty using mobile- and fixed-bearings

The Arthrotic knee is frequently associated with several-pain and loosening of joint function often so important to need a total knee arthroplasty (TKA). Obviously, the aims of a TKA is to obtain no pain and restore a good joint function so to contribute to a good health and a better quality life. To realize ends like these it’s necessary a good selection of the patients first, an adequate preparation for the surgery, correct surgery technique and a specific post-operative rehabilitation until achieving the normal daily activities. In this way clinical biomechanical evaluations can contribute to quantify the achievement of the ends and they can get influence to modulate the “ways” used. Actually the dynamic evaluation more useful and reproducible in the gonartrhosis is the gait analysis. Patients were selected from a group of subjects suffering from advanced gonartrhosis. Exclusion criteria from the study were: bilateral advanced arthrosis; previous surgery at the lower limbs or other disease that could influence the gait pattern. With these criteria a group of 7 males and 2 females, mean age 67,7 years old, participated at the study (after a known consensus). All subjects had clinical evaluation. For the dynamic analysis The knee society evaluation system for arthroplasty was used. The knee stability was evaluated on the frontal and mediolateralaxis. For evaluating the pain entity we used the V.A.S. score at rest and during gait, before and after taking the analgesic drug. In addition standard X-ray of the knees were evaluated. Gait Analysis was performed at the biomechanical laboratory “Let people move” of Perugia (Italy). Subjects walked on a track of 12,5 m., a 3Dcinematic evaluation was performed using the APAS system (ARIEL Dynamics, USA) with 4 high speed video cameras. 15 auto reflexed markers were applied on both lower limbs. The ground reaction forces during the gait were recorded at 500 Hz with Bertec platform placed at the centre of there cording area. At the subjects was asked to make 10 valid trials (5 for right and 5 for left knee). During gait was evaluated the range of motion of ankle and foot too. The mean score obtained with the V.A.S. score for the pain during the first section was 3.3 (range 0–7). After taking the analgesic drug and 20 minutes of rest the range was 0–4 at the sequent trial. The results so obtained said that there’s no difference between the range of motion of the knee after taking the drug on the sagittal plane. In addition, no difference neither between the range of motion of the hip and the ankle, on the sagittal plane after the drug. The mean score obtained with the V.A.S. score for the pain during the first section was 3.3 (range 0–7). After taking the analgesic drug and 20 minutes of rest the range was 0–4 at the sequent trial. The results so obtained said that there’s no difference between the range of motion of the knee after taking the drug on the sagittal plane. In addition, no difference neither between the range of motion of the hip and the ankle, on the sagittal plane after the drug

BACKGROUND. Many patients who underwent a THA, report a feeling of more “physiological” hip and of faster recovery when bigger heads are used. The aim of this study is to evaluate the walking recovery of patients after THA with different head diameters by the means of gait analysis. MATERIALS AND METHODS. A prospective, randomized, blind study was conducted on 60 patients operated by THA at our Institution. Inclusion criteria were: primary hip arthritis, women, age between 55 and 70 years. Exclusion criteria were: other problems influencing walking ability (previous operations of the lower limbs, spine disorders, knee or controlateral hip arthritis). The same uncemented stem, same uncemented press-fit cup, same surgical technique and approach (posterolateral), same surgeons, same postoperative protocol and rehabilitation were employed. The only difference was the head diameter. The patients were randomized into three groups, of twenty patients each one (28mm Cer-on-XPE, 36mm Cer-on-XPE, >42mm Met-on-Met). The gait evaluation have been performed at three temporal steps: preoperatively, two months postoperatively and four months postoperatively. Kinematic parameters were acquired with Elite opto-electronic system (BTS, Milan, Italy) equipped with 6 cameras at 100 Hz frame rate. The system is integrated with a force platform (Kistler, CH) and a synchronic video system using two cameras (BTS, Milan, Italy). Data acquisition and processing were carried out using passive markers positioned according to Davis protocol. At least ten trials for each session were collected in order to assess the repeatability of the results. Gait analysis included kinematic parameters (temporal-spatial parameters and joint angular values) and kinetic parameters (ground interaction forces during walking). Articular moments and powers were computed on the basis of data obtained from dynamometric platform along with those given by kinematic analysis. All patients were compared to a control group. Wilcoxon signed rank test was employed for statistical evaluation. RESULTS. At a preliminary evaluation (still in progress) and statistical analysis, temporal-spatial parameters show no significant differences among the three groups. All the variables of step length, stride length, cadence and velocity show statistical significant improvements towards the standard values, in the four months follow-up in all the groups, and the improvement does not depend on the side operated. CONCLUSIONS. The preliminary evaluation of this study shows that there is no statistical significant difference in standard gait analysis parameters in patients with different head diameters (28mm, 36mm, >42mm) after THA

Purpose of the study: How does a total knee arthroplasty (TKA) function? Do all prostheses provide the excellent results reported in the literature? This gait analysis compared patients with a TKA versus normal subjects in order to obtain a 3D quantification of the kinematic and dynamic differences between patients with a very good functional result and controls. Material and methods: Twenty patients who had a TKA for less than one year and whose functional outcome was scored very good (KSS knee > 85/100, VAS ≤1/10) were compared in a double blind study with 20 normal controls. The knees were masked so that the investigators were unaware of the type of subject (operated or not), the side operated, or the type of implant. The analysis as performed on an AMTI platform with six infrared cameras which followed the displacements of 36 reflectors. Motion Analysis software was applied. The gait parameters recorded were: speed, step length, flexion angle, duration of weight bearing/oscillation phases, and dynamic variables: flexion-extension moment, varus-valgus moment, internal/external rotation moment. Results: Adjusted for age and height, step length, walking speed, and duration of the weight bearing phase were identical in the operated and control populations. Kinematic and dynamic variables demonstrated significant differences. At lift-off, all of the TKA subjects were in functional permanent flexion (m=10); the flexion moment of the quadriceps was less than in the non-operated subjects. In the frontal plane, the weight-bearing phase was identical between the operated subjects and controls, but with a varus dynamic (m=4) during the oscillating phase. In the horizontal plane, there was an external rotation of the tibia (m=+5) during weight bearing. Discussion: Gait analysis provides quantitative information which is not perceptible at physical examination nor with videoscopic explorations. Even patients with an excellent KSS score exhibit important anomalies despite the fact that the physical exam finds a normal range of motion and normal muscle force. The degree by degree 3D gait analysis reveals the difference. Conclusion: Despite a clinical score considered to be very good, patients with a TKA have a functional deficit of the extensor system during take-off, even when the knee has complete active extension; the weight-bearing phase of the step is in external rotation and the oscillating phase exhibits varus laxity

Ankle arthrodesis for isolated ankle arthritis has a high patient satisfaction level; however, gait analysis and functional outcome measurements demonstrate substantial disability. The high patient satisfaction may reflect the extent of disability present prior to the intervention. This study demonstrates that the presence of subtalar or talonavicular arthritis and/or limited motion is a negative predictor for a satisfactory outcome. The risk of developing arthritis of these joints increases with time and therefore the patient can expect a deterioration of their initial result. Ankle arthrodesis should be considered a salvage procedure. Viable alternatives that preserve motion should continue to be explored. The purpose of this study was to utilize gait analysis and validated outcome measures to assess the results of an ankle arthrodesis and compare these results to a healthy age – sex matched control group. Isolated Ankle arthrodesis has a high patient satisfaction rate; however, gait analysis and functional outcome scores demonstrate a significant difference when compared to controls. The presence of limited subtalar and midfoot motion and/or arthritis correlates with a poor clinical result. This study will help the clinician predict outcomes and better educate patients as to the expected results following ankle arthrodesis. Twenty-six patients with an isolated ankle arthrodesis underwent gait analysis and functional outcome assessment using AOFAS ankle-hindfoot scale, MODEMS (includes SF-36) and Ankle Osteoarthritis Scale (AOS). A radiographic analysis was preformed. Mean follow-up was 3.7 years. Results were compared to a group of twenty-six controls. Seventy-seven percent were satisfied and eighty-eight percent would recommend it to a friend. These perceived outcomes did not correlate well with their average Functional Outcome scores and gait analysis. The AOFAS score rated 46% as excellent or good. The MODEMS identified significant differences in Physical Function, Role-Physical and Physical Composite means when compared to controls. The AOS identified significant differences in Pain and Disability means. Gait analysis demonstrated significant differences in stride length, cadence, hip flexion, hindfoot flexion, hindfoot inversion and midfoot flexion. Decreased hindfoot and midfoot motion correlated with poorer outcome scores. Poor radiographic scores correlated with decreased hindfoot/midfoot motion and poorer clinical outcomes. Ankle arthrodesis should be considered a salvage procedure. Viable alternatives that preserve ankle motion should continue to be explored

Aim of study: To assess ankle dorsiflexion of operated pedes equinovari congenitales in both clinical examination and gait analysis. Introduction: Mac Kay subtalar release corrects mostly perfectly deformed feet. Operated feet show however stiffness not only in subtalar but as well as in ankle joint. The range of motion in ankle joint was not yet studied systematically at all. Gait analysis offers the possibility to follow the motion in ankle joint dynamically. Material: Thirty six consecutively operated feet were examined by clinical as well as by gait analysis examination. All were operated by Mac Kay procedure at least one year before examination (range 1–7 years). Feet were examined in lying and stance positions. Gait analysis was based on use of Oxford foot model (8 cameras motion capture system). Results: Dorsiflexion/plantiflexion of the foot estimated by clinical examination was compared with maximum dorsiflexion in phase of mid-stance (second rocker)/maximum plantiflexion in pre-swing phase (third rocker). Differences individually for each patients in dorsiflexion/plantiflexion were calculated. Mean of difference between dorsiflexion in clinical examination and dorsiflexion in gait analysis x = 14.3°. Mean of diference between plantiflexion in clinical examination and plantiflexion in gait analysis x= 5,4°. Using T-paired test these differences were found statistically significant (p=0,01). Normal maximum dorsiflexion of the children’ foot in gait analysis is about 20°. From this point 14 operated feet out from 36 did not fulfill this criterion. On the other hand only 4 operated feet showed in gait analysis dorsiflexion less than 10°. Discussion: Dorsiflexion of the foot is important for smooth gait. The diference between dates from clinical examination and dates from gait lab can be explained by weight - bearing force pushing the foot into dorsiflexion during second rocker or by secondary adaptive intrinsic bending of the foot. Conclusion: Operated feet showed moderate/severe stiffnes of ankle joint. Despite of it, the gait cycle was not significantly impaired

Introduction: Mobile bearing total knee arthroplasty (TKA) has been developed to theoretically provide better, more physiological function of the knee and produce less PE wear. The theoretical superiority of mobile bearing TKAs over fixed bearing devices has not yet been proven in clinical studies. The objective of the present study was to prospectively analyze clinical and functional outcomes of randomized fixed and mobile bearing total knee arthroplasty patients by means of gait analysis, electromyography and established clinical scores. Methods: In a prospective, randomized, patient- and observer-blinded, clinical study, 33 patients (mean age 63 years) received a cruciate retaining Genesis II TKA for primary osteoarthritis. 16 patients received a mobile bearing and 17 patients a fixed bearing device. The day before surgery and 24 months postoperatively, established clinical (KSS, HSS, WOMAC, UCLA, VAS) and quality of life (SF-36) scores were used to compare both patient groups. Electromyography of standardized locations was measured with the MyoSystem 2000 and analyzed with Myoresearch software. Gait analysis was performed with a six camera motion analysis system and force platforms. Results: Both groups showed significant improvements between pre- and postoperative evaluation in gait analysis and electromyography, but gait analysis results as well electromyography did not show any difference between both groups at follow-up. Clinical and quality of life results significantly improved from pre- to postoperative evaluation, but only the Knee Society Score showed a significant superiority of the mobile bearing group (mean 159.0; SD 27.7; range, 105–196) over the fixed bearing group (mean 134.4; SD 41; range, 56–198) (p=0.0022). Conclusions: In the present study, no functional advantage of mobile bearing TKA over fixed bearing devices could be found, although the mobile bearing group had better clinical results. Thus, long-term clinical results and in-vivo wear analyses have to be followed, and more subtle functional analyses (e.g. fluoroscopy) have to be employed to finally judge over the theoretical advantage of mobile bearing TKAs

Performing Total Knee Replacement (TKR) surgery using computer assisted navigation systems results in more reproducibly accurate component alignment. Navigation allows real time evaluation of passive knee behaviour throughout flexion. These kinematic measurements reflect tibial rotation about the femoral condyles, patellar tracking and soft tissue balance throughout surgery. In this study, we aim to study dynamic knee function in navigated and standard instrumentation TKR patients performing a range of everyday activities using gait analysis. A prospective randomised controlled trial evaluated the functional outcome using gait analysis with 20 patients in each of three groups – Standard, Navigated and Control. The same implant (Scorpio) and navigation system (Strykervision) was used for each patient. The control group were subjects with no history of knee pathology or gait abnormality. Using an 8-camera Vicon motion analysis system set at 120Hz (real-time motion), we assessed the following functional activies: walking, rising from/sitting in chair, ascending/descending stairs. One functional outcome measure we have analysed so far is the maximum flexion angle. The maximum flexion angle was recorded for each activity in standard, navigated and control groups respectively. ANOVA was performed, with significance set at p< 0.05. Maximum flexion angle during gait was 65.6°, 72.6° (p=0.009) and 73.5° (p=0.74), chair rising/sitting was 82.5°, 92.8° (p=0.01), and 93.5° (p=0.64), stairs ascent/descent was 81.8°, 99° (p< 0.0001), and 113.4° (p< 0.0001). In terms of dynamic functional outcome, we found that the average maximum flexion angle for the navigated group was greater than for the standard group; moreover, this was similar to the maximum flexion angle for the control group when performing a variety of normal daily activities

Background. There are limited previous findings detailed biomechanical properties following implantation with mechanical and kinematic alignment method in robotic total knee arthroplasty (TKA) during walking. The purpose of this study was to compare clinical and radiological outcomes between two groups and gait analysis of kinematic, and kinetic parameters during walking to identify difference between two alignment method in robotic total knee arthroplasty. Methods. Sixty patients were randomly assigned to undergo robotic-assisted TKA using either the mechanical (30 patients) or the kinematic (30 patients) alignment method. Clinical outcomes including varus and valgus laxities, ROM, HSS, KSS and WOMAC scores and radiological outcomes were evaluated. And ten age and gender matched patients of each group underwent gait analysis (Optic gait analysis system composed with 12 camera system and four force plate integrated) at minimum 5 years post-surgery. We evaluated parameters including knee varus moment and knee varus force, and find out the difference between two groups. Results. The mean follow up duration of both group was 8.1 years (mechanical method) and 8.0 years (kinematic method). Clinical outcome between two groups showed no significant difference in ROM, HSS, WOMAC, KSS pain score at last follow up. Varus and valgus laxity assessments showed no significant inter-group difference. We could not find any significant difference in mechanical alignment of the lower limb and perioperative complicatoin. In gait analysis, no significant spatiotemporal, kinematic or kinetic parameter differences including knee varus moment (mechanical=0.33, kinematic=0.16 P0.5) and knee varus force (mechanical=0.34, kinematic=0.37 P0.5) were observed between mechanical and kinematic groups. Conclusions. The results of this study show that mechanical and kinematic alignment method provide comparable clinical and radiological outcomes after robotic total knee arthroplasty in average 8 years follow-up. And no functional difference were found between two knee alignment methods during walking

Background. There are limited previous findings detailed biomechanical properties following implantation with mechanical and kinematic alignment method in robotic total knee arthroplasty (TKA) during walking. The purpose of this study was to compare clinical and radiological outcomes between two groups and gait analysis of kinematic, and kinetic parameters during walking to identify difference between two alignment method in robotic total knee arthroplasty. Methods. Sixty patients were randomly assigned to undergo robotic-assisted TKA using either the mechanical (30 patients) or the kinematic (30 patients) alignment method. Clinical outcomes including varus and valgus laxities, ROM, HSS, KSS and WOMAC scores and radiological outcomes were evaluated. And ten age and gender matched patients of each group underwent gait analysis (Optic gait analysis system composed with 12 camera system and four force plate integrated) at minimum 5 years post-surgery. We evaluated parameters including knee varus moment and knee varus force, and find out the difference between two groups. Results. The mean follow up duration of both groups was 8.1 years (mechanical method) and 8.0 years (kinematic method). Clinical outcome between two groups showed no significant difference in ROM, HSS, WOMAC, KSS pain score at last follow up. Varus and valgus laxity assessments showed no significant inter-group difference. We could not find any significant difference in mechanical alignment of the lower limb and perioperative complicatoin. In gait analysis, no significant spatiotemporal, kinematic or kinetic parameter differences including knee varus moment (mechanical=0.33, kinematic=0.16 P0.5) and knee varus force (mechanical=0.34, kinematic=0.37 P0.5) were observed between mechanical and kinematic groups. Conclusions. The results of this study show that mechanical and kinematic alignment method provide comparable clinical and radiological outcomes after robotic total knee arthroplasty in average 8 years follow-up. And no functional differences were found between two knee alignment methods during walking

Background: Congenital absence of the cruciate ligaments is a commonly associated pathology of the knee joint in congenital longitudinal deformities. We performed a radiological analysis and investigated gait patterns in patients with congenital absence of one or both cruciate ligaments. Patients and Methods: Thirty-four knee joints in thirty-one patients with congenital longitudinal deficiency of the lower limb were evaluated. The cruciate ligaments and associated abnormalities of the bony configuration were evaluated on magnetic resonance imaging and tunnel view radiographs. A radiological classification is proposed. Gait analysis was employed to determine kinematic, kinetic and electromyographic data in 24 of these patients and the results were compared to an age-matched control group. Results: We differentiated 3 main types of absence of the cruciate ligaments with typical associated changes in the femoral intercondylar notch (FIN) and the tibial eminence (TE). In type I (n=19) partial closure of the FIN and hypoplasia of the TE was observed in hypoplasia or absence of the ACL, in type II (n=7) these findings were aggravated by additional underlying hypoplasia of the PCL and in type III (n=8) absence of the FIN and a flat TE was observed in aplasia of both cruciate ligaments. The main findings in gait analysis were significantly increased flexion moment of the hip, increased flexion of the knee in midstance phase and reduced ankle power in comparison to the control group. Conclusion: The knee joint with aplastic cruciate ligaments shows typical radiological changes, thus, one will be able to distinguish between aplasia of the ACL only or both cruciate ligaments by observing plain tunnel view radiographs. Our obtained data of the gait analysis revealed specific gait patterns as adaption to underlying aplasia of the cruciate ligaments

Introduction. Surgical techniques for implant alignment in total knee arthroplasty (TKA) is a expanding field as manufacturers introduce patient-specific cutting blocks derived from 3D reconstructions of pre-operative imaging, commonly MRI or CT. The patient-specific OtisMed system uses a detailed MRI scan of the knee for 3D reconstruction to estimate the kinematic axis, dictating the cutting planes in the custom-fit cutting blocks machined for each patient. The resulting planned alignment can vary greatly from a neutral mechanical axis. The purpose of this study was to evaluate the early fixation of components in subjects randomized to receive shape match derived kinematic alignment or conventional alignment using computer navigation. A subset of subjects were evaluated with gait analysis. Methods. Fifty-one patients were randomized to receive a cruciate retaining cemented total knees (Triathlon, Stryker) using computer navigation aiming for neutral mechanical axis (standard of care) or patient-specific cutting blocks (OtisMed custom-fit blocks, Stryker). Pre-operatively, all subjects had MRI scans for cutting block construction to maintain blinding. RSA exams and health outcome questionnaires were performed post-operatively at 6 week, 3, 6, and 12 month follow-ups. A subset (9 subjects) of the patient-specific group underwent gait analysis (Optotrak TM 3020, AMTI force platforms) one-year post-TKA, capturing three dimensional (3D) knee joint angles and kinematics. Principal component analysis (PCA) was applied to the 3D gait angles and moments of the patient-specific group, a case-matched control group, and 60 previously collected asymptomatic subjects. Results. Five MRI scans for surgical planning were not useable due to motion artifacts, with 2 successfully rescanned. Ligament releases were performed in 62% of navigation cases and 32% of patient-specific cases. One patient-specific case was revised for failure of the cruciate ligament, resulting in a polyethylene liner exchange for a thicker, cruciate substituting insert. Implant migration at 1 year was 0.40±0.25 mm for the patient-specific group and 0.37±0.20 mm for the navigation group (maximum total point motions; t-test P=0.65). EQ-5D scores, Oxford Knee scores, satisfaction, pain, and range of motion were not different between groups at any follow-up to 1 year, including the polyethylene liner exchange case. The gait analysis showed that there were no statistical differences between groups. PCA captured a lower early stance phase flexion moment magnitude in the patient-specific group than the computer navigated recipients, bringing patterns further away from asymptomatic characteristics (flexion moment PC2, P=0.02). Conclusions. Implant migration was not different between groups at 1 year despite differences in implant alignment methods. Subject function and satisfaction were also not different between groups, despite significantly fewer ligament releases in the patient-specific group. However, gait analysis of a subgroup has not shown an improvement towards restoring asymptotic gait. It should be acknowledged that the production of patient-specific cutting blocks may not be possible for all patients due to the MRI scanning requirements. Continued evaluation with RSA to 2 years will be performed to monitor these subjects over the longer term

In arthritis of the varus knee, a high tibial osteotomy (HTO) redistributes load from the diseased medial compartment to the unaffected lateral compartment. We report the outcome of 36 patients (33 men and three women) with 42 varus, arthritic knees who underwent HTO and dynamic correction using a Garches external fixator until they felt that normal alignment had been restored. The mean age of the patients was 54.11 years (34 to 68). Normal alignment was achieved at a mean 5.5 weeks (3 to 10) post-operatively. Radiographs, gait analysis and visual analogue scores for pain were measured pre- and post-operatively, at one year and at medium-term follow-up (mean six years; 2 to 10). Failure was defined as conversion to knee arthroplasty. . Pre-operative gait analysis divided the 42 knees into two equal groups with high (17 patients) or low (19 patients) adductor moments. After correction, a statistically significant (p < 0.001, t-test,) change in adductor moment was achieved and maintained in both groups, with a rate of failure of three knees (7.1%), and 89% (95% confidence interval (CI) 84.9 to 94.7) survivorship at medium-term follow-up. At final follow-up, after a mean of 15.9 years (12 to 20), there was a survivorship of 59% (95% CI 59.6 to 68.9) irrespective of adductor moment group, with a mean time to conversion to knee arthroplasty of 9.5 years (3 to 18; 95% confidence interval ± 2.5). . HTO remains a useful option in the medium-term for the treatment of medial compartment osteoarthritis of the knee but does not last in the long-term. . Cite this article: Bone Joint J 2016;98-B:601–7

Purpose of the study: The aim of this study was to analyze the mechanical function of the ankle after implantation of a total ankle arthroplasty. Gait analysis included kinematic and dynamic parameters of the lower limbs before and after prosthesis implantation in comparison with ankle fusion. Material and methods: This prospective non-randomized study included three cohorts of patients. The first cohort included 12 patients presenting osteoarthritic lesions of the ankle requiring total ankle arthroplasty; these 12 patients were reviewed six months postoperatively and for six of them twelve months postoperatively. The second cohort was composed of 12 patients reviewed twelve months after tibiotalar arthrodesis. The third cohort was composed of 12 healthy volunteers who participated in the same study protocol. The gait analysis was conducted with the Motion Analysis optoelectronic system. Parameters recorded were: self-selected speed, fastest speed, stride rate, step length, stride symmetry and length, symmetry of floor contact, and symmetry of toe lift-off. In addition, patients participated in specific tests to step over an obstacle and go up and down stairs. Results: Gail was slower an asymmetrical in patients with ankle fusion. Fusion enabled good recovery of gait speed but at the cost of imbalanced weight-bearing times and asymmetrical toe lift-off. Total ankle arthrodesis provided little improvement in gait speed but enabled progressive and persistent recovery of symmetrical gait. Discussion: It is well established that an ankle prosthesis improved joint force and motion in comparison with the osteoarthritic ankle. Fusion provides good clinical and kinetic results but at the const of compensation by the joints above and below the ankle. Few studies have examined gait symmetry which in our opinion would be a good criterion for evaluating the quality of gait. Conclusion: The raw data obtained in this study demonstrate that patients with an osteoarthritic or fused ankle can recover gait speed but that they retain a limp. Total ankle arthroplasty enables a more balanced fluid and symmetrical gait which is much more comfortable for the patient

Background: Mobile-bearing knee replacements have some theoretical advantages over fixed-bearing devices. However, very few randomized controlled clinical trials have been published to date, and studies showed little clinical and subjective advantages for the mobile-bearing using traditional systems of scoring. The choice of the ideal outcome measure to assess total joint replacement remains a complex issue. However, gait analysis provides objective and quantifying evidences of treatment evaluation. Significant methodological advances are currently made in gait analysis laboratories and ambulatory gait devices are now available. The goal of this study was to provide gait parameters as a new objective method to assess total knee arthroplasty outcome between patients with fixed- and mobile-bearing, using an ambulatory device with minimal sensor configuration. Methods: This randomized controlled double-blind study included to date 31 patients: the gait signatures of 12 patients with mobile-bearing were compared to the gait signatures of 19 patients with fixed-bearing pre-operatively and post-operatively at 6 weeks, 3 months and 6 months. Each participant was asked to perform two walking trials of 30m long at his/her preferred speed and to complete a EQ-5D questionnaire, a WOMAC and Knee Society Score (KSS). Lower limbs rotations were measured by four miniature angular rate sensors mounted respectively, on each shank and thigh. Results: Better relative differences between pre-operative and post-operative 3 months and 6 months KSS (122% vs 34% at 3 months, 138% vs 36% at 6 months) and KSS function (154% vs 8% at 3 months, 183% vs 42% at 6 months) scores were observed for the fixed-bearing compared to the mobile-bearing. The same better improvements for fixed-bearing were also found with the range of knee angles (Affected side: 31% vs −5% at 3 months, 47% vs 5% at 6 months), (Unaffected side: 16% vs 5% at 3 months, 15% vs 6% at 6 months) and peak swing speeds of shank (Affected side: 18% vs −2% at 3 months, 30% vs 4% at 6 months), (Unaffected side: 8% vs −3% at 3 months, 7% vs 4% at 6 months). Conclusions: A new method for a portable system for gait analysis has been developed with very encouraging results regarding the objective outcome of total knee arthroplasty using mobile- and fixed-bearings

Introduction: Fibular hemimelia (FH) is a congenital limb reduction deficiency characterised by partial or complete absence of the fibula and a spectrum of associated anomalies. For children with a major anticipated limb length discrepancy and severe foot deformity, management (amputation or limb reconstruction) is controversial. Materials and Methods: 8 children who are now adults (average age 28 years) underwent limb reconstruction as children in one of two UK centres for severe fibular hemimelia. All 8 participants were recalled to our institution for instrumented gait analysis. The SF-36 and lower limb domains of the Toronto Extremity Salvage Score (TESS) questionnaires were also administered. Results: Partcipants scored well for general health but had functional limitations reflected in lower TESS scores. Kinematic analysis revealed decreased sagittal knee motion and valgus knee alignment. Also ubiquitous were anterior pelvic tilt and obliquity with incomplete hip extension and reduced range of hip abduction. Kinetic analysis showed reduced peak plantar flexion moment with reduced push-off power and an internal hip adduction moment in late stance. These parameters are compared to control data for below knee amputees. Discussion and conclusions: Although the number of participants is small, this is the first study to use instrumented gait analysis for severe fibular hemimelia managed with limb reconstruction. The results add objective data to the debate over limb reconstruction or amputation in this group of children

This randomized clinical trial compares fixed- and mobile-bearing total knee prostheses in terms of the patients’ clinical outcome parameters (Knee Society Clinical Rating, WOMAC, SF-12), range of motion and performance during gait analysis for level-ground walking. Our results show no significant differences in the clinical outcomes and gait performance of the fixed- and mobile-bearing total knee arthroplasties. The purpose of this study was to compare the clinical outcomes and gait parameters of patients with a fixed-bearing or mobile-bearing total knee arthroplasty (TKA). Fifty-five patients were entered into a prospective, randomized clinical trial comparing fixed- versus mobile-bearing TKAs (Genesis II, Smith & Nephew, Memphis, TN). From this patient population, fifteen fixed-bearing and fifteen mobile-bearing TKA patients were matched based on age, sex and BMI to undergo gait analysis. Patients performed trials of level-ground walking at a self-selected velocity while three-dimensional kinetic and kinematic data were collected. The fixed-bearing and mobile-bearing TKA patient groups were comparable regarding Knee Society Clinical Rating (181 ± 22 versus 171 ± 28), WOMAC scores (7 ± 5 versus 9 ± 12), SF-12 and range of motion (121° ± 11° versus 125° ± 6°). Patients with fixed- and mobile-bearing TKAs performed similarly in the gait analysis in terms of their velocity, percent weight acceptance in the operated versus the non-operated limb, peak flexion in stance and swing phases, the support moments and extension moments at the ankle, knee and hip. Decreased peak extension in the mid-stance and swing phases was observed in the operative limb versus the non-operative limb for both fixed- and mobile-bearing TKAs (P=0.02 and 0.04). Decreased peak extension was also observed during mid-stance and swing phases in the mobile-bearing TKAs versus the fixed-bearing TKAs (P=0.064 and 0.052). Fixed-bearing and mobile-bearing TKAs perform similarly in terms of their clinical outcome measures and the kinetics and kinematics of level-ground walking. Funding for this project obtained from Smith & Nephew, Memphis, TN

The purpose of the study was to evaluate the functional outcome of different limb salvage procedures for osteosarcoma about the knee. A selection of patients who have undergone limb salvage procedures for osteosarcoma about the knee were invited to join the study. Medical and operation notes were reviewed along with recent radiographs of the involved limb. Patients completed the Musculoskeletal Tumour Society functional questionnaire and underwent a gait analysis assessing walking and running. Most patients had stage 2B osteosarcoma involving either the proximal tibia or distal femur. Limb salvage procedures included arthrodesis, allograft reconstruction, endoprosthesis and rotationplasty. All patients scored highly (> 70 %) on the MSTS questionnaire except the arthrodesis that scored 57 %. The gait analysis revealed some subtle changes with a quadriceps-sparing gait in the endoprosthesis, mild foot drop in the proximal tibial allograft and a lateral lean of the trunk over the ipsilateral limb in the rotationplasty. The arthrodesis had an obvious straight leg gait with subtle pelvic hiking to assist foot clearance. While analysis of walking was close to normal most patients were unable to obtain a double float and run. This study shows that limb salvage procedures tailored to each individual case can result in an excellent functional outcome with close to normal gait and high MSTS scores

Over a 4 year period 27 children with cerebral palsy underwent proximal femoral derotation osteotomy resulting in a total of 42 operations performed. Each of these children had pre operative gait analysis performed followed by derotation osteotomy. The degree of derotation varied individually and was judged to be correct when the foot lay in a neutral position. Gait analysis was not repeated until 1 year after surgery to allow for complete bony union, recovery of the soft tissues and general patient rehabilitation. Pre-operative and post-operative data were compared to give a quantitative analysis of the actual derotation obtained. The mean age at the time of operation was 9.7 years (range 4.5–14.5 years). The male : female ration was 6 : 5. the mean amount of femoral derotation achieved was 26.25 degrees (minimum 7 degrees, maximum 66 degrees). The goal of the operation was to correct internal rotation and achieve a hip in a neutral position throughout the majority of the gait cycle. The average hip rotation in a normal able-bodied person is 1.72 degrees of external rotation. 84% achieved more than 75% derotation to neutral. The remainder were considered operational failures. These results quantitatively demonstrate that proximal femoral derotation osteotomy is a successful operation in cerebral palsy to correct intoeing

Conventional fixed-bearing (FB) knee prostheses have been proved clinically successful. Rotating platform, mobile-bearing (MB) total knee replacements (TKR) have been developed to improve knee kinematics, lower contact stresses on the polyethylene tibial component, minimize constraint, and allow implant self-alignment. The purpose of this study was to characterize and compare the functional outcome of FB- and MB- TKR during gait and deep knee bends, using a motion analysis system. Two groups of five patients with a unilateral FB TKR (PFC) or MB TKR (LCS) underwent a gait analysis study. The normal contralateral limb was used as a control to compare data in the stance phase of gait. Demographic, clinical, and radiographic data were equivalent in the 2 groups. Both MB and FB TKRs gave good functional results in spite of different design rationales. No statistically significant difference was demonstrated between the two groups. However, gait and knee function after TKR was abnormal even though the patients were asymptomatic. A flexional pattern for flex-ion-extension moments at the knee during level walking was present in both types of TKR. Differences in rotational moments between the two groups were observed, with a higher internal rotational moment in the PFC group (PFC, 0.14 Nm/kg; LCS, 0.09 Nm/kg; p=0.094). A stressful weightbearing activity, such as deep knee bends, amplified the functional differences between the different prosthetic designs, indicating that knee kinematics are activity-dependent. Kinetic and kinematic differences noted between the 2 groups reflect different patterns of joint surface motion and loading, with postulated effects on long term failure of the implants through wear, mechanical failure, and loosening. Gait analysis using external skin markers has a limited role in the characterization of the joint surface motion of the prosthetic knee during ambulatory activities because of errors and assumptions inherent in the technique. However, it provides scope for the study of kinetic parameters acting on different knee prostheses during gait

Summary Statment. The dual-mobility cup seems to bring more stability without changing the gait pattern. Introduction. Dislocations and instability are among the worst complications after THA in elderly patient. Dual mobility cups seem to lower these risks. To our knowledge no study performed a gait analysis of dual cup in this group. Methods. Our team implanted 52 dual mobility cups (Gyros, de Puy J&J Corporation) before 2007. 7 hip revisions and 15 primary hips were reviewed in 20 patients. The mean age at the review was 79.8 years old. 15 died or were mentally too disabled to perform a gait analysis. 5 didn't give consent for a clinical study and 8 were not localizable. We performed a gait analysis using a non-invasive miniature sensors device (PhysilogTM) when patients walked freely on a flat ground. We compared our results to a control group of frail eldery patients of the same age who didn't sufferd of orthopedic condition and to a group of patient with a conventional THA from our institution and to the literature. The WOMAC and Harris Hip scores were also computed. Results. None of the 22 hips faced dislocation. The gait analysis showed good results that were superior to those of the control group of frail elderly and comparable to those of conventional THA. The cadence was of 100,3 steps/min, the double stance of 23,3%, the stance of 61,6%, the stride of 1,13 meters and the walking speed of 0,96 m/s. The mean HHS and WOMAC were 87,6 (51–100) and 11,3 (0–34). Conclusion. Our results at 5 years compared favorably with the current litterature. The increase of stability didn't impared the walking performances

Aim We set out to see. whether ankle replacements were capable of maintaining a normal gait and. whether ankle replacements were superior to arthrodeses in maintaining a normal gait pattern. Method We performed gait analysis on 15 patients, with 13 ankle replacements (mixture of Buechel Pappas and Scandinavian Total Ankle Replacement [STAR]) and three ankle arthrodeses. One patient had an ankle replacement on one side and an arthrodesis on the other. We used a standard seven camera infrared system and force plate at a frequency of 240Hz. There were a mixture of patients with osteoarthritis and rheumatoid arthritis. We also looked at the ‘normal’ side of the patients with unilateral surgery. Results We found that patients with ankle replacements had near normal gait parameters for both kinetic and kinematic data whereas patients with ankle fusions had significantly altered kinetic and kinematic data. This was both in respect to normal individuals and to the unoperated side. Patients with rheumatoid arthritis had some alteration in the gait pattern on the normal side – the presence of an ankle replacement on the other side maintained this pattern on the operated side, suggesting that this was not due to abnormalities within the ankle but in the rest of the foot and lower limb. Patients with unilateral osteoarthritis for which they had an ankle replacement had essentially normal kinetics and kinematics of both ankles. Conclusion We have been able to show that an ankle replacement performs well in terms of restoring/maintaining a normal gait pattern, whereas ankle arthrodesis, although gives a functional and pain free foot, significantly alters the normal gait pattern

We studied 50 patients before and after unilateral total hip replacement, and compared them, using gait analysis, with 22 having staged bilateral operations. The average age of the patients was 65 years at the first operation. The mean follow-up was 53 months for the unilateral cases and 27 months, after the second THR, for the bilateral cases. The average interval between first and second THR was 24 months. Patients with bilateral hip disease did not gain optimal function, even on the first side, until both hips had been replaced. Unilateral replacement gave better gait analysis results than did either side after bilateral procedures

Introduction: Numerous studies in the orthopaedic literature have reported changes in knee kinematics following rupture of the Anterior Cruciate Ligament (ACL). Gait analysis is currently the preferred method for studying these in vivo kinematics. The accuracy of this method of analysis remains limited due to errors related to skin movement artefact. Most studies have therefore been limited to analysing subjects performing simple tasks such as straight-line walking, since results become increasingly inaccurate as the subject moves faster. Standard skin marker formats allow measurements of knee flexion angle and varus/valgus angles to be recorded relatively accurately during such tasks. Accurate measurements of rotations and translations at the knee joint, however, are not possible with these set-ups. Aim: To produce a new method for interpretation of kinematic data from gait analysis, to allow accurate measurement of 3-D displacements at the knee joint during dynamic activity. Method: We employed two different sets of skin markers in an attempt to increase the accuracy of our data, by diminishing the effects of skin movement. The Kabada. 1. marker set was used with retroreflective spheres of 14.5mm diameter. This marker set was used to establish 3-D femoral and tibial co-ordinate systems. We then established a femoral and tibial co-ordinate centre within the distal femur and proximal tibia respectively. A second set of markers was used similar to the “point-cluster” method described by Andriacchi et al. 2. This involved groups of eight smaller spheres (9.5mm diameter) placed in a non-uniform distribution on each of the thigh and shank segments. The positions of all these remaining markers, relative to the co-ordinate centres were then established. 15 subjects were then recorded while performing a series of running and cutting tasks. For each trial that was then analysed, we used all visible markers to optimize the recorded position of the tibial and femoral co-ordinate centres, using a method similar to that described by Soderkvist. 3. The displacements of these co-ordinate centres were then used to calculate the 3-D tibio-femoral kinematics. Reliability and repeatability tests suggest that this method produces results accurate to 3–4mm. Conclusion: We believe we have developed a practical and accurate method to analyse 3-D joint kinematics from gait laboratory data

Many studies describe the use of the Ilizarov ring fixator for lower limb lengthening and for the management of the 3-dimensional lower limb deformities in achondroplasia, and most confirm the efficacy of this technique. However, long term follow up of these achondroplastic patients is lacking. Most studies have focused on magnitude of lengthening, treatment time required and complications, but no study has analyzed the long term postoperative condition of these patients using an objective, functional method such as gait analysis. Nineteen (19) achondroplastic patients, 12 males and 7 females, aged 19–38 years (mean 27.3 y) who have undergone tibia and femur lengthening, using the Ilizarov method, at the age of 9–19 years (mean 12.6 y), were evaluated 5–19 years (mean 10.1 y) after their last surgery, using 3-dimensional gait analysis. Nineteen (19) normal, height-matched subjects were used as controls. The VICON Nexus 8 Camera System was used to accurately measure spatiotemporal characteristics (walking velocity, stride length, step length, cadence) and kinematics (range of motion) of lower limb joints. Statistical comparison of deformity parameters between achondroplastic patients and normal population was done using the student t- test. A level of p<0.05 was considered statistically significant. Walking velocity, step length and stride length were statistically significantly decreased (p<0.05) in achondroplastic patients compared to normal population values. The achondroplastic group presented with excessive anterior pelvic tilt (mean 21.9. o. ± 7.3), excessive pelvic rotation (range 28.7. o. ±7.8), decreased hip extension (mean 1.8. o. ±10.1) and decreased plantar flexion (mean 17.1. o. ±5.1) when compared to normal controls. There was no statistically significant difference in the knee kinematics between the operated achondroplastic patients and normal controls. The achondroplastic patients present decreased values in their spatiotemporal characteristics compared to the normal subjects because, despite the height gain, their lower limbs remain shorter. Their excessive anterior pelvic tilt is attributed to their lordosis. Their excessive forward pelvic rotation is an attempt to increase stride and step length. The decreased hip extension is due to their anterior pelvic tilt. The correction of these patients genu varum restored knee kinematics to normal. In order to address the hip and pelvis deformities a proximal femoral osteotomy should be considered. The Ilizarov method provides functional height gain and substantially corrects the three-dimensional lower limb deformities of achondroplastic patients especially around the knee joint but more planning needs to be implemented when the system is applied to correct the disease specific deformities of the hip and pelvis. Gait analysis is an objective tool that can be used to address these design issues

Introduction. In prosthetic knee surgery, the axis of the lower limb is often determined only by static radiographic analysis. However, it is relevant to determine if this axis varies during walking, as this may alter the stresses on the implants. The aim of this study was to determine whether pre-operative measurement of the mechanical femorotibial axis (mFTA) varies between static and dynamic analysis in isolated medial femorotibial osteoarthritis. Methods. Twenty patients scheduled for robotic-assisted medial unicompartmental knee arthroplasty (UKA) were included in this prospective study. We compared three measurements of the coronal femorotibial axis: in a static and weightbearing position (on long leg radiographs), in a dynamic but non-weightbearing position (intra-operative acquisition during robotic-assisted UKA), and in a dynamic and weightbearing position (during walking by a gait analysis). Results. There was no significant difference in the mFTA between radiological (173.9 ± 3.3°), robotic (174.4 ± 3.4°), and gait analysis (172.9 ± 5.1°) measurements (p < 0.05). Conclusion. There is no significant variation in varus between lying, standing, and while walking in patients who are candidates for medial UKA. This study also allows us to validate the accuracy of the robotic system in varus estimation, and to rely on intra-operative planning as it also reflects the dynamic knee under load

Introduction: Traditionally, the degree of correction for derotational femoral osteotomies in cerebral palsy has been based on clinical or radiographic measures. Recently, three dimensional gait analysis has been used to plan and evaluate orthopaedic surgery. Our aim was to assess the outcome of derotation osteotomies, where the degree of rotation at surgery was guided by transverse plane kinematics (aiming at reducing peak hip rotations to normal limits). Method: Pre and post-operative gait analyses were reviewed in a group of these patients (16 legs) and compared with a similar group of 8 patients (16 legs) who had soft tissue procedures only. Results: Improvement following derotation osteotomy occurred in all but one case; 11/16 osteotomies resulted in peak internal rotation within one standard deviation (SD) of peak normal internal rotation (normal range −6° to +11°), the other 4 were within 1.4 SDs. Discussion: Objective improvement in hip rotation during gait was measured in 15/16 subjects undergoing dero-tation osteotomy based on gait analysis. There was no rotational change overall in patients who had soft tissue procedures only. Average dynamic correction of internal rotation during gait was slightly less than intra-operative correction, possibly due to tensioning of spastic muscles

The purpose of this study is to assess the clinical outcome and gait analysis of a new technique for ankle arthrodesis using a Fibular Sparing Z Osteotomy (FSZO). The FSZO technique for ankle arthrodesis utilises a lateral approach where the fibula is osteotomised and reflected posteriorly on a soft tissue hinge to allow easy access to the ankle joint for an anatomic arthrodesis. Outcome assessment at six months follow up included health related quality of life (SF36) and joint specific (American Orthopedic Foot and Ankle Society Ankle-Hindfoot, Ankle Osteoarthritis Scale, Foot Function Index) clinical outcome scores. Gait Analysis was completed using the Walkabout Portable Gait Monitor® which includes a wireless gait belt housing a triaxial arrangement of accelerometers, resting behind the lumbar vertebrae, approximately at position of centre of mass to quatintfy surgery, lurch and functional limb length difference (LLD). There was a significant improvement in the health related quality of life and the joint specific clinical outcome scores at six months follow up. The six month gait study preliminary analysis showed improvement in some parameters of gait but worsening in others. The FSZO ankle arthrodesis technique provides improvement in clinical outcome scores and certain gait parameters at early follow up

Introduction and Aims: The effects of injury to the posterior cruciate ligament (PCL) and posterior-lateral corner (PLC) on physical function are not as well documented compared to the more common injury to the anterior cruciate ligament. This study aimed at improving our understanding of PCL/PLC injury through gait analysis and electromyographic (EMG) testing. Method: We studied 19 patients, average age 30 years (20–55) with clinically and radiologically confirmed PCL/PLC deficiency in isolation. Ninety percent of patients complained of instability when performing the activities of daily living and all complained of pain. All patients were assessed using the Lysholm and Gillquist functional knee score as well as gait analysis, including Kinematics, Kinetics and EMG of the quadriceps, hamstrings and gastrocnemius muscles. Findings were compared to our normal database. The mean Lysholm score was 51/100 (24–90). Those with a Lysholm greater than 50 were designated as ‘copers’. Results: There were 12 ‘non-copers’ and seven ‘copers’. Fifty percent of patients demonstrated a varus thrust through stance. Forty-two percent of patients demonstrated hyperextension of the knee through stance. Sixty-three percent of patients demonstrated premature and prolonged hamstring activity. Thirty-seven percent of patients had premature activity of the gastrocnemius muscle in stance. Fifty-seven percent of the ‘copers’ demonstrated premature and prolonged hamstring activity through the gait cycle compared to forty-five percent of ‘non-copers’ (non-significant p=0.25 Fishers Exact Test). Fifty-five of ‘non-copers’ demonstrated premature activity of the gastrocnemius muscle in stance compared to none of the ‘copers’ (significant p=0.025 Fishers Exact Test). Conclusion: The observed varus thrust may be responsible for the development of medial and patellofemoral compartment osteoarthritis, a recognised problem in PCL deficient knees. Hyperextension that occurs dynamically during gait could explain failure of PCL/PLC reconstruction over time. The observed abnormal hamstrings activity is unlikely to be a compensatory mechanism

INTRODUCTION. Mobile-bearing knee prostheses have been designed in order to provide less constrained knee kinematics compared to fixed-bearing prosthesis. Currently, there is no evidence to confirm the superiority of either of the two implants with regard to walking performances. It has been shown that subjective outcome scores correlate poorly with real walking performance and it has been recommended to obtain an additional assessment of walking ability with objective gait analysis. OBJECTIVES. We assessed recovery after total knee arthroplasty (TKA) with mobile- and fixed-bearing between patients during the first postoperative year, and at 5 years follow-up, using a new objective method to measure gait parameters in real life conditions. METHODS. 56 patients with mobile- and fixed-bearing of the same design were included in this randomised controlled double-blinded study and evaluated pre- and post-operatively at 6 weeks, 3 months, 6 months 1 year and 5 years. At each visit a WOMAC and Knee Society Score were calculated and each participant completed an EQ-5D questionnaire. To assess the patients' gait five miniature angular rate sensors mounted respectively on the sacrum and each shank and thigh measured lower limb movement and rotation. The patients walked 30 metres on a flat surface and gait parameters were recorded with a small ambulatory device in order to carry out an objective gait analysis. RESULTS. Objective recovery was strongly correlated with patients' age. When the whole population was considered, there was no significant difference between groups at any time in objective gait parameters. After separating the population according to their age (less than 71 years old, compared to those of more than 71 years old) a secondary analysis showed that the bearing type can lead to opposite results in different age groups. At five years follow-up, most of the recorded gait parameters (stride length, knee max rotation speed, shank and thigh range of motion, and limp) showed better results for mobile bearing in younger patients, while better gait performances were found systematically with fixed-bearing TKA in older patients. CONCLUSION. To our knowledge, this is the first study where similarly designed posterior-stabilised knee replacements with fixed- and mobile-bearing have been compared with gait analysis in real-life conditions. We observed systematically differences between mobile and fixed bearing groups, which are confirmed by multivariate analysis. Our results suggest that older patients might not benefit from a mobile bearing TKA and that extended age controlled study should be performed to identify an age, above which fixed bearing should not be the recommended choice. Before choosing the bearing type, surgeons should take into account the age of the patient

Aim: To quantify the gait characteristics of the children with a history of treated femoral shaft fracture, and compare the outcome of three different treatment methods (spica cast, plate fixation, and flexible intramedullary nailing) in terms of kinematic and kinetic characteristics of gait. Material and Methods: Fifteen children (9 boys, 8 girls), admitted to our hospital for unilateral (n=12) and bilateral (n=3) femoral fracture were evaluated in this study. The average age was 9.4 years (range 5–15 years). They were treated by three different methods: spica cast (n=5 ), plate fixation (n= 5), flexible intra-medullary nailing (n= 5). The cases were followed up with an average period of 23 months (6–48 months). At the end of the follow up period quantitative gait analysis was performed using Vicon 370 system with five cameras and two Bertec force plates. For each assessment, a typical walk was selected for each limb on the basis of consistency of time-distance characteristics. Kinematic and kinetic gait characteristics were compared using MANOVA, post hoc Tukey and LSD tests. Results: Gait characteristics of the patients were significantly different than normal, however, the difference between spica cast, plate fixation, and flexible intra-medullary nailing groups in terms of kinematic and kinetic characteristics of gait were not statistically significant. Older children treated by spica cast showed the best gait characteristics among the others. Conclusion: Femoral shaft fractures during childhood causes significant deviations of gait characteristics even though treated by spica cast, plate fixation, or flexible intra-medullary nailing. These children need novel treatment options to prevent gait pathologies, and further evaluation to understand the compensatory mechanisms of gait deviations

Aims. Conventional patient-reported surveys, used for patients undergoing total hip arthroplasty (THA), are limited by subjectivity and recall bias. Objective functional evaluation, such as gait analysis, to delineate a patient’s functional capacity and customize surgical interventions, may address these shortcomings. This systematic review endeavours to investigate the application of objective functional assessments in appraising individuals undergoing THA. Methods. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were applied. Eligible studies of THA patients that conducted at least one type of objective functional assessment both pre- and postoperatively were identified through Embase, Medline/PubMed, and Cochrane Central database-searching from inception to 15 September 2023. The assessments included were subgrouped for analysis: gait analysis, motion analysis, wearables, and strength tests. Results. A total of 130 studies using 15 distinct objective functional assessment methods (FAMs) were identified. The most frequently used method was instrumented gait/motion analysis, followed by the Timed-Up-and-Go test (TUG), 6 minute walk test, timed stair climbing test, and various strength tests. These assessments were characterized by their diagnostic precision and applicability to daily activities. Wearables were frequently used, offering cost-effectiveness and remote monitoring benefits. However, their accuracy and potential discomfort for patients must be considered. Conclusion. The integration of objective functional assessments in THA presents promise as a progress-tracking modality for improving patient outcomes. Gait analysis and the TUG, along with advancing wearable sensor technology, have the potential to enhance patient care, surgical planning, and rehabilitation. Cite this article: Bone Joint J 2024;106-B(8):764–774

Aims: Purpose of this retrospective study was to evaluate changes of pressure distribution during walking and joint movement after clubfootoperation. Methods: For this analysis the VICON 512 motion system including 12 cameras and 2 KISTLER force plates were used. Pressure distribution under both feet during gait was measured by a pressure sensitive plate (EMED NOVEL pressure plate). Muscle activity of the lateral and medial gastrocnemicus, anterior tibialis and longer peroneal muscles was registered by surface EMG using BIOVISION. The sampling rate of the motion analysis system was set at 120 Hz. Data acquisition of force and EMG signals were performed at 1080 Hz. The kinematic analysis of the human body was represented by a 7-segment model consisting of feet, lower legs, upper legs and pelvis. A set of 16 markers were used to identify the body segments. Results: 20 children with a mean age of 12 years underwent a quantitative 3-dimensional kinematic and kinetic gait analysis. Regarding to gait pattern a wide range from normal to equinal was found. Measurement of the pressure distribution during walking showed maximum pressure at different foot regions. There were only a few children with “normal” gait pattern. The striking gait pattern was combined with higher dorsalflexion in the ankle joint, missing extension and higher flexion in the knee joint. A lower extension in the hip joint was also found. Conclusions: A wide range of gait pattern was found during 3-dimensional analysis after clubfoot-operation by using the Imhaeuser method. Reasons could be the rehabilitation after operation and different daily activities of life. Work in progress is still the comparison with other methods

Purpose of the study: The effect of idiopathic scoliosis surgery on walking capacity has rare been studied. Results published in the literature have been discordant: reduced velocity, step rate and stride length for Lenke et al; no change for Engsber et al. We conducted a prospective study to analyze gait parameters after surgery for idiopathic scoliosis. Material and methods: This study was conducted in 46 patients who underwent surgery for idiopathic scoliosis. Mean age was 15 years (range 12–22). Mean angle was 56° (range 40–94°). A posterior approach was used for reduction and fusion in all patients. Mean postoperative angle was 20° (range 8–64°). There were no neurological, mechanical or infectious complications. Gait analysis was performed with a locometer to record spatial and temporal gait parameters preoperatively then postoperatively at 10 days, and 3, 6, and 12 months. ANOVA was performed. Results: Preoperatively, mean±SD values were: velocity: 1.48±0.14 m/s; step rate: 132±9 steps/min; stride length 67±6.7 cm; balancing time: 0.39±0.03 s; double-stance time 0.07±0.03 s. These values were lower than reported for health adults using the same measurement instrument. All parameters were modified immediately after surgery (p< 0.05) but there was no significant difference between the pre- and postoperative values at 3, 6, and 12 months. Conclusion: Corrective fusion via a posterior approach for the treatment of idiopathic scoliosis does not affect spatial and temporal gait parameters

The choice of surgical technique for total hip arthroplasty (THA) can affect time and postoperative rehabilitation procedures. The aim of this prospective blinded cohort study is to determine significant differences in gait parameters in the short term between those patients who have experienced THA using a limited incision anterolateral intermuscular (MIS) approach compared with those who have experienced traditional lateral transmuscular (LTM) approach. Thirty patients were enrolled in this study, 15 of who received the MIS technique and 15 the LTM approach. A single surgeon performed all the operations using short hip stem implants with 36mm femoral head size and all patients received a standard postoperative rehabilitation protocol. Patients, physiotherapists, and assessors were blinded to the incision used. Gait analysis was performed 30 day after surgery, when patients were able to ambulate without crutches. Minimal differences in temporostatial parameters were shown between the MIS and LTM groups, whereas significant differences (p< 0.05) in kinematics (hip range of motion in sagittal, frontal and transverse planes), kinetics (hip flexion/extension and abduction/adduction moments) and electromiography parameters (gluteus medius activation pattern and degree of activity) between two groups. This study demonstrates functional benefits of the minimally invasive incision over the standard lateral transmuscular approach in terms of walking ability 30 days postoperatively

Introduction: Ankle arthropathy is associated with a decreased motion of the ankle-hindfoot during ambulation. Ankle arthrodesis was shown to result in degeneration of the neighbour joints of the foot. Inversely, total ankle arthroplasty conceptually preserves the adjacent joints because of the residual mobility of the ankle but this has not been demonstrated yet in vivo. It has also been reported that degenerative ankle diseases, and even arthrodesis, do not result in alteration of the knee and hip joints. We present the preliminary results of a new approach of this problem based on ambulatory gait analysis. Patients and Methods: Motion analysis of the lower limbs was performed using a Physilog® (BioAGM, CH) system consisting of three-dimensional (3D) accelerometer and gyroscope, coupled to a magnetic system (Liberty©, Polhemus, USA). Both systems have been validated. Three groups of two patients were included into this pilot study and compared to healthy subjects (controls) during level walking: patients with ankle osteoarthritis (group 1), patients treated by ankle arthrodesis (group 2), patients treated by total ankle prosthesis (group 3). Results: Motion patterns of all analyzed joints over more than 20 gait cycles in each subject were highly repeatable. Motion amplitude of the ankle-hindfoot in control patients was similar to recently reported results. Ankle arthrodesis limited the motion of the ankle-hindfoot in the sagittal and horizontal planes. The prosthetic ankle allowed a more physiologic movement in the sagittal plane only. Ankle arthritis and its treatments did not influence the range of motion of the knee and hip joint during stance phase, excepted for a slight decrease of the hip flexion in groups 1 and 2. Conclusion: The reliability of the system was shown by the repeatability of the consecutive measurements. The results of this preliminary study were similar to those obtained through laboratory gait analysis. However, our system has the advantage to allow ambulatory analysis of 3D kinematics of the lower limbs outside of a gait laboratory and in real life conditions. To our knowledge this is a new concept in the analysis of ankle arthropathy and its treatments. Therefore, there is a potential to address specific questions like the difficult comparison of the benefits of ankle arthroplasty versus arthrodesis. The encouraging results of this pilot study offer the perspective to analyze the consequences of ankle arthropathy and its treatments on the biomechanics of the lower limbs ambulatory, in vivo and in daily life conditions

Accelerometer based gait analysis (AGA) is a potential alternative to the more commonly used skin marker based optical motion analysis system(OMAS). The use of gyroscopes in conjunction with accelerometers (i.e. inertial sensors), enables the assessment of position and angular movements of body segments and provides ambulatory kinematic characterisation of gait. We investigated commonly used gait parameters and also a novel parameter, Pelvic obliquity (PO) and whether they can be used as a parameter of physical function and correlate with classic clinical outcome scores. Gait was studied in healthy subjects (n=20), in patients with end stage hip OA (n=20) and in patients with end stage knee OA (n=20). Subjects walked 20 metres in an indoor environment along a straight flat corridor at their own preferred speed. A 3D inertial sensor was positioned centrally between the posterior superior iliac spines (PSIS) overlying S1. Comparing gait parameters of end stage hip OA patients with an age and gender matched healthy control group, significantly lower walking speed, longer step duration and shorter step length was observed. After correcting for walking speed between groups, significantly less average range of motion of PO (RoM. po. ) was observed for patients with end stage hip OA compared to healthy subjects and patients with end stage knee OA. IGA allows objective assessment of physical function for everyday clinical practice and allows assessment of functional parameters beyond time only. IGA measures another dimension of physical function and could be used supplementary to monitor recovery of OA patients after TJR

Aims:Understanding total knee replacement mechanics and their influence on patient mobility requires accurate analysis of both operated joint accurate kinematics and full body kinematics and kinetics. The main aim of this study is to perform these two analyses conjointly, as never been reported previously. An innovative graphic-based interface is also pursued aimed at supporting quantitative functional assessment of these patients during the execution of daily living motor tasks in a single synchronized view. Methods: Three-dimensional fluoroscopic and gait analysis were carried out on eleven patients with PCL-retaining mobile bearing (Interax ISA, Stryker / How-medica / Ostetonics) and on ten posterior stabilized fixed bearing (Optetrak PS, Exactech) knee prostheses. Patients performed three trials of stair ascent twice on the same day: first in the radiology department for fluoroscopy acquisition and later in the Movement Analysis Laboratory, utilizing an identical staircase. Three-dimensional fluoroscopic analysis entails reconstruction of absolute and relative positions and orientations of the two metal components in space by analyzing series of fluoroscopic images of the operated knee and utilizing knowledge of the 3D cad models of these components. Conventional stereophotogrammetry and dynamometry were used to calculate kinematics and kinetics of the trunk, pelvis and of the major joints of the lower limb. An advanced computer-based interface was developed (MULTIMOD, EU-funded project: IST-2000-28377) to show together a) original video of the patient tasks, b) 3D graphical representation of bony segment motion, c) original fluoroscopic images, d) 3D reconstruction of prosthesis component relative motion, and e) graphical transverse plane representation of the contact areas at the base-plate of the replaced knee. All these were registered in space and synchronized in time. Results: No significant statistical differences on clinical data were found between the two patient populations. Observations at the interface allowed distinct identification of the most critical phases of the task and of the most common compensatory mechanisms utilized by these patients. Statistically significant correlation was found between knee flexion at foot strike and the position of the mid-condylar contact points, and between maximum knee adduction moment and corresponding lateral trunk tilt. Conclusions: A more complete and powerful assessment of the functional performances of different TKR designs is obtained by combining gait and fluoroscopic in-vivo analyses, which provide correlated and synergic quantitative information

Introduction. Post-operative gait abnormalities are recognized following total hip arthroplasty (THA). Despite global improvement in functional outcome, gait abnormality persists for a decade or more. In this study 3-dimensional gait analysis (3DGA) was performed using a portable system with Inertial Measurement Units (IMUs) to quantify this abnormality. Methods. The gait of 55 patients with monarthrodial hip arthrosis was measured pre-operatively and at one year post-surgery. Patients with medical co-morbidity or other conditions affecting their gait were excluded. Six IMUs were aligned at the level of the anterior superior iliac spines, mid-thigh and mid-leg. Data was analysed using proprietary software. Each patient underwent a conventional THA using a posterolateral approach. 92 healthy individuals were assessed for comparison. Results. Pre-operative movement in the sagittal plane of the ipsilateral hip (mean range 20.4) and the contra-lateral non-diseased hip (35.3 degrees) was reduced compared to the control group (40.5 degrees), (P<0.001). The pre-operative movement of both knees was reduced compared with normal (P<0.001). Pelvic movement on the ipsilateral side was increased. After one year ipsilateral hip movement significantly improved (Mean range 28.9 deg SD 6.6) but did not reach normal values (P<0.001). Movement measured in the contralateral hip was further reduced with a mean difference of −5.25 degrees (95% CI −8.06 to −2.43). Knee movement on both sides increased but not to normal values (p<0.001). There was increased coronal movement bilaterally at the thigh and calf one year after surgery. Discussion and Conclusion. Gait after routine THA does not return to normal. Unilateral hip pathology causes bilateral gait abnormality affecting the entire kinematic chain. This portable technology allows practical assessment of gait in the outpatient setting and will enable identification of key aspects of gait abnormality to target during rehabilitation following THA

Ambulating children with bilateral spastic cerebral palsy (BSCP) demonstrate atypical posture and gait due to abnormal muscle and skeletal growth when compared to typically–developing (TD) children. Normal postural alignment in standing facilitates many of the tasks of daily living because it allows a stable base of support without requiring significant muscular effort. Similarly, increasing gait abnormality is associated with poorer functional capacity. Our aims were to compare the standing posture of TD children and children with BSCP using the Standing Profile Score and identify if any abnormality in standing is correlated with abnormality in walking in children with BSCP using the Gait Profile Score index. We retrospectively compared 44 typically-developing children to 74 age-matched children with BSCP (GMFCS I & II). We performed 3D Gait Analysis during long-standing (10seconds) and in gait after application of 16 retro-reflective markers on anatomical landmarks of the lower limb and pelvis. Analysis of all kinematics was performed for movements in the sagittal, coronal and axial planes. The Gait Profile score (GPS) is a validated index of overall gait pathology. The Standing Profile Score (SPS) was developed using the same calculations for GPS but during static trials. A significant correlation was observed between the Standing Profile Score (SPS) and Gait Profile Score (GPS) in children with BSCP (p<0.001). Significant differences were exhibited in GPS between the two groups, across all parameters, except the pelvic obliquity (p<0.05). A significant positive correlation existed for hip rotation in both groups, however the correlations observed at hip flexion and ankle dorsiflexion were significantly greater in the BSCP group compare to the TD group (p<0.01). We have shown that posture during gait (GPS) is predictable from standing posture (SPS) in patients with BSCP. This biomechanical relationship can aid surgical decision-making

Aims: Minimal invasive total hip replacement is supposed to allow a quicker rehabilitation in the immediate post-operative period due to reduced soft tissue damage. The aim of this study is to compare gait kinematics after total hip arthroplasty using a one incision minimal invasive approach to a traditional approach. Matarial and Methods: 21 patients were available for a complete analysis. In 12 patients (MIS group) a minimal invasive, modified Watson-Jones approach was used, in 9 patients (Standard group) a transgluteal approach as described by Bauer was used. All operations were performed by a single surgeon with the patient in supine position. In all cases the same cementless implant (Alloclassic® VariallTM system) with standard instruments was used. 3D gait analysis was carried out pre-operatively, 10 days postoperatively and after 3 months. The variables analysed in this study were velocity, step length, range of hip extension, range of pelvic tilt, Trendelenburg’s sign and Duchenne limp, pelvic rotation and symmetry. Results: There were no significant differences between the MIS and the Standard group in any of the evaluated variables. In both groups of the patients presented a decrease in the hip extension at the end of stance phase 10 days postoperatively. About half of these patients compensated with an increased sagital pelvic tilt during maximal hip extension. At the 3 months follow-up all patients in both groups had an increased hip extension compared to the preoperative values, reached normative values. The velocity was reduced in both groups at the 10 days follow-up, ¼ reached normative values after 3 months. Conclusion: Our data show no significant improvement of gait kinematics in patients who underwent a total hip arthroplasty using a minimal invasive approach (modified Watson-Jones) compared to a standard approach (Bauer) during the early postoperative period

Aims. To evaluate inducing osteoarthritis (OA) by surgical destabilization of the medial meniscus (DMM) in mice with and without a stereomicroscope. Methods. Based on sample size calculation, 70 male C57BL/6 mice were randomly assigned to three surgery groups: DMM aided by a stereomicroscope; DMM by naked eye; or sham surgery. The group information was blinded to researchers. Mice underwent static weightbearing, von Frey test, and gait analysis at two-week intervals from eight to 16 weeks after surgery. Histological grade of OA was determined with the Osteoarthritis Research Society International (OARSI) scoring system. Results. Surgical DMM with or without stereomicroscope led to decrease in the mean of weightbearing percentages (-20.64% vs -21.44%, p = 0.792) and paw withdrawal response thresholds (-21.35% vs -24.65%, p = 0.327) of the hind limbs. However, the coefficient of variation (CV) of weight-bearing percentages and paw withdrawal response thresholds in naked-eye group were significantly greater than that in the microscope group (19.82% vs 6.94%, p < 0.001; 21.85% vs 9.86%, p < 0.001). The gait analysis showed a similar pattern. Cartilage degeneration was observed in both DMM-surgery groups, evidenced by increased OARSI scores (summed score: 11.23 vs 11.43, p = 0.842), but the microscope group showed less variation in OARSI score than the naked-eye group (CV: 21.03% vs 32.44%; p = 0.032). Conclusion. Although surgical DMM aided by stereomicroscope is technically difficult, it produces a relatively more homogeneous OA model in terms of the discrete degree of pain behaviours and histopathological grading when compared with surgical DMM without stereomicroscope. Cite this article: Bone Joint Res 2022;11(8):518–527

Due to abnormal neuromuscular development, functional capability in children with cerebral palsy is often severely compromised. Single event multi-level surgery (SEMLS) is the gold standard surgical treatment for patients with cerebral palsy. It has been demonstrated to improve gait, however, how standing posture is affected is unknown. The aim was to investigate the effect of SEMLS in patients with spastic cerebral palsy on walking and standing posture using 3D gait analysis. Participants were identified from the One Small Step Gait Laboratory database. Standardised 3D-Gait analysis was performed within 2 years pre- and post-SEMLS. Gait abnormality was measured using the Gait Profile Score (GPS) index; standing abnormality was measured using the newly-developed Standing Profile Score (SPS) index. A control group (n=20) of age/sex-matched CP patients who did not undergo surgery were also assessed. 104 patients (73 boys, 31 girls) with spastic cerebral palsy underwent SEMLS with appropriate pre- and post-gait analyses (2000–2015). 91 patients had bilateral limb involvement, 14 had unilateral limb involvement. Average age at surgery was 10.38 years (range 4.85–15.60 years). A total of 341 procedures were performed, with hamstring and gastrocnemius lengthening representing approximately 65% of this. There was a 20% mean improvement in walking (GPS reduced 2.4°, p<0.001) and standing (SPS reduced 3.4°, p<0.001) following SEMLS. No improvement was noted in the control group. Significant correlations were observed between the changes in SPS and GPS following surgery (r2, p<0.001). Patients with poorer pre-operative standing posture (SPS) reported the most significant improvement following surgery. We confirmed improvement in walking following SEMLS using the Gait Profile Score (GPS). This is the first paper to report that standing posture is also improved following surgery using a novel index, the Standing Posture Score (SPS). SPS could be adopted as a tool to assess functional capability and predict post-operative changes

We studied the results of multi-level surgical intervention for children with cerebral palsy. Thirty patients, aged 7–16 years, with spastic diplegia (n=20), or spastic hemiplegia (n=10) were studied prospectively by gait analysis. Multilevel surgery included a combination of psoas lengthening, medial hamstring lengthening, rectus femoris transfer and gastrocnemius lengthening +/− foot surgery or femoral derotation osteotomies. Gait analyses were carried out pre-op and at 6 and 24 months post-op. Children with spastic diplegia increased their walking velocity by an average of 20% at two years (p< 0.05). Mean stride length increased from 89cm pre-op to 102cm at two years (p< 0.05) with similar improvements in both groups of children. Maximum knee extension in stance improved from an average 17.5 degrees flexion pre-operatively to an average 5 degrees flexion postoperatively (p< 0.05). Peak knee flexion in swing was maintained and the timing improved. Peak ankle dorsiflexion in stance was unchanged following surgery but the timing of peak ankle dorsiflexion was normalised to late stance (from 24% of cycle pre-operatively to 48% of cycle post-operatively (norm = 48%). Average maximum hip extension in stance did not change. The mean anterior pelvic tilt did not change post-operatively. However, a number of children with spastic diplegia had increased anterior pelvic tilt post-operatively. These results are similar to those reported internationally, with most improvement seen distally at the knee and ankle and less improvement at the hip. Increased anterior pelvic tilt was seen as a consequence of hamstring lengthening in some more involved patients

To evaluate the gait of five-year old children with club-feet initially treated non-operatively with the French functional technique and to compare these results to the data from this same cohort at the age of two years. Thirty-three patients (fifty-two idiopathic clubfeet) were initially treated with the French functional (physiotherapy) program. At the age of two years, no child underwent surgery for its clubfoot. Gait Analysis was performed with the VICON system (kinematics). At the age of five years, these patients were all re-evaluated in the gait laboratory. Of the thirty-three patients (fifty-two clubfeet) initially treated non-operatively and tested in the gait lab at two years of age, thirty-seven feet required subsequent surgery by the age of five years. This included posterior release (41%), posteromedial release (35%), tibial osteotomy (19%), and tendo Achilles lengthening (5%). The proportion of feet with the following gait parameters changed significantly (p< 0.05) between the ages of two and five years: Equinus (15% at 2 yrs vs. 2% at 5 yrs), Calcaneus (7% vs. 23%), Foot Drop (18% vs. 4%). The proportion of patients with internal foot progression angle did not change over this time (46% vs. 50%), nor did the proportion with normal sagittal plane ankle motion (61% vs. 54%). At age two years, the majority of patients treated with the French Functional non-operative treatment had normal sagittal plane ankle motion. Gait disturbances, when present at this age, were generally ankle equinus, foot drop and in-toeing. By the age of five years, 71% of these patients underwent surgery for their clubfeet. When re-tested in the gait laboratory at age five years, the proportion of feet with normal sagittal plane ankle motion did not change significantly, however, their resultant gait disturbances, when present, were predominantly calcaneus rather than equinus and foot drop. By treating patients with clubfeet with the French Functional technique exclusively, equinus gait may result in a small proportion. By subsequently treating these patients surgically after the age of two years, over-lengthening or over-release may occur and result in calcaneus gait. The French originators of this technique now incorporate an early gastrocsnemius fascial lengthening as part of their technique. This modification of their technique should improve the gait characteristics observed at two years of age and should decrease the necessity for late surgery that may have contributed to the gait characteristics observed at five years of age

Background

The cruciate ligaments are important structures for biomechanical stability of the knee. For total knee arthroplasty (TKA), understanding of the exact function of the (PCL) and anterior (ACL) cruciate ligament during walking is important in the light of recent designs of bicruciate TKAs. However, studies evaluating in vivo function of the PCL during daily activities such as walking are scarce. We aimed to assess the role of the PCL during gait by measuring kinematics and kinetics of individuals with PCL deficiency and compare them with individuals with ACL deficiency and healthy young adults.

Introduction: A key to the analysis of function after joint replacement is the ability to identify gait adaptations specific to design features. In a prospective controlled design, we evaluated mechanics of gait in the hip joint after total hip replacement (THR) with use of two different types of implants. We also investigated whether adaptations to gait normalized postoperatively. Material and Methods: Thirty patients were randomized to receive a hip resurfacing system (HRS group) or conventional hybrid prosthesis (MHE group). Twenty-22 patients underwent three-dimensional gait analysis 6 and 12 weeks postoperatively. To evaluate normalization of gait parameter variables in the hip joint after THR, we used data from 22 age- and sex-matched healthy controls. Results: We found similar postoperative improvements in mechanics of gait in the hip joint between the groups, except for peak abductor moments, which improved more in the MHE group. HRS and MHE groups were similar with respect to level of peak values. Three months after surgery, most peak values were significantly different between operated and non-operated hip in all THR patients. Mean curves of kinetic and kinematic variables of THR patients and healthy controls showed that gait adaptations in the hip joint were not normalized after 3 months. Conclusion: We found no evidence for the hypothesis that one implant was superior to the other in normalizing gait adaptation. Although THR patients improved considerably and significantly in almost all gait parameter variables of the hip, gait impairments persisted. Our results may indicate the need of gait retraining in conjunction with intensive muscle strengthening to improve function and longevity of implants, especially among young patients

Objectives. To evaluate the effects of ankle/hindfoot arthrodesis in rheumatoid arthritis (RA) patients on gait pattern of the knee and hip. Methods. In this prospective follow-up study 14 RA patients scheduled for ankle/hindfoot arthrodesis were included. Three-dimensional gait analyses of joint angles, moments and work were performed at the index operation and after 13 months of follow-up. Each patient underwent clinical assessments of pain while walking, overall evaluation of disease activity, Health Related Quality of Life Questionnaire (EQ-5D), activity limitations, maximum walking distance, difficulty with walking surface and gait abnormality. For comparisons of pre- versus post-operative conditions, Wilcoxon’s matched pairs test and Friedman ANOVA by rank test were used. Results. At follow-up after ankle/hindfoot fusion surgery, RA patients demonstrated a statistically significant improvement in mean range of joint motions, moments and work in the overlying joints such as the knee and hip. Moreover, there was significantly less pain, disease activity, activity limitation, difficulty with walking surface and gait abnormality. EQ-5D and maximum walking distance were also significantly improved at follow-up. Conclusions. Our results demonstrate that ankle/hindfoot arthrodesis in RA is an effective intervention to reduce pain and to improve Health Related Quality of Life and functional ability. Moreover, the overlying leg joints experience an improvement in joint motion, muscle-generated joint moments and work during walking. Three-dimensional gait analysis may assist future investigations of the effects of orthopaedic surgery on functional mobility in RA to prevent irreversible disablement

Patella and extensor mechanism injuries are common injuries and are generally managed with some degree of immobilisation and partial weight bearing to facilitate healing. The aim of this project was to determine the type of immobilisation or splintage during partial weight bearing that results in minimal forces acting through the extensor mechanism. Gait analysis studies were performed on eight healthy male subjects mobilising partially weight bearing. Measurements were taken for six types of immobilisation: locked at 0, 10, 20, 30 degrees and unlocked in an orthotic knee brace, and without a brace. The ground reaction force, knee joint angle and the knee flexion moment were measured using Qualisys Track Manager and Visual 3D Software. The extensor mechanism moment and the extensor mechanism force were calculated using static equilibrium equations and documented data. A one-way analysis of variance statistical test was performed to determine the statistical significance of the differences between the six types of immobilisation. There was a direct relationship between the knee flex-ion angle and the extensor mechanism force. The extensor mechanism force at 0 degrees of immobilisation was significantly lower than that for 20 and 30 degrees (p< 0.05). The increase in the extensor mechanism moment arm with increasing knee flexion was not suf-ficient to offset the increase in the extensor mechanism force caused by the increase in the knee flexion moment. The results also showed that the knee flexion angle does not always correspond with the angle set at the knee brace; however they did exhibit a direct relationship. These results have important implications for the management of patients with patella and extensor mechanism injuries. The results suggest that improvements in knee brace design to allow 0 degrees of knee flexion, rather than the 10 degrees as seen in this study, are likely to result in significantly reduced extensor mechanism tensile forces

Aims. Total knee arthroplasty (TKA) may provoke ankle symptoms. The aim of this study was to validate the impact of the preoperative mechanical tibiofemoral angle (mTFA), the talar tilt (TT) on ankle symptoms after TKA, and assess changes in the range of motion (ROM) of the subtalar joint, foot posture, and ankle laxity. Methods. Patients who underwent TKA from September 2020 to September 2021 were prospectively included. Inclusion criteria were primary end-stage osteoarthritis (Kellgren-Lawrence stage IV) of the knee. Exclusion criteria were missed follow-up visit, post-traumatic pathologies of the foot, and neurological disorders. Radiological angles measured included the mTFA, hindfoot alignment view angle, and TT. The Foot Function Index (FFI) score was assessed. Gait analyses were conducted to measure mediolateral changes of the gait line and ankle laxity was tested using an ankle arthrometer. All parameters were acquired one week pre- and three months postoperatively. Results. A total of 69 patients (varus n = 45; valgus n = 24) underwent TKA and completed the postoperative follow-up visit. Of these, 16 patients (23.2%) reported the onset or progression of ankle symptoms. Varus patients with increased ankle symptoms after TKA had a significantly higher pre- and postoperative TT. Valgus patients with ankle symptoms after TKA showed a pathologically lateralized gait line which could not be corrected through TKA. Patients who reported increased ankle pain neither had a decreased ROM of the subtalar joint nor increased ankle laxity following TKA. The preoperative mTFA did not correlate with the postoperative FFI (r = 0.037; p = 0.759). Conclusion. Approximately one-quarter of the patients developed ankle pain after TKA. If patients complain about ankle symptoms after TKA, standing radiographs of the ankle and a gait analysis could help in detecting a malaligned TT or a pathological gait. Cite this article: Bone Joint J 2023;105-B(11):1159–1167

Background

High functional aspirations and an active ageing population equate to a growing number of patients awaiting hip arthroplasty demanding superior biomechanical function. The purpose of this study was to compare the biomechanics of top walking speed between two commonly used hip arthroplasty procedures to determine if a performance advantage existed.

Osteoarthritis of the first metatarsophalangeal (MTP1) joint is a common disorder in elderly, resulting in pain and disability. Arthrodesis of this joint shows satisfactory results, with relieve of pain in approximately 85% of the patients. However, the compensation mechanism for loss of motion in the MTP1 joint after MTP1 arthrodesis is unknown. A reduced compensation mechanism of the foot may explain the disappointing result of MTP1 arthrodesis in the remaining 15% of the patients. This study was conducted to elucidate this compensation mechanism. We hypothesize that the ankle and forefoot are responsible for compensation after MTP1 arthrodesis.

Gait was evaluated in eight patients with arthrodesis of the MTP1 joint (10 feet) and twelve healthy controls (21 feet) by using a sixteen-camera Vicon-system. The four-segmental, validated Oxford-Foot-Model was used to investigate differences in range of motion of the hindfoot-tibia, forefoot-hindfoot and hallux-forefoot segment during stance. For statistical analysis, the unpaired t-test with Bonferroni correction (p<0.0125) was performed.

No differences in spatiotemporal parameters were observed between both groups. In the frontal plane, MTP1 arthrodesis decreased the range of motion in midstance, while an increased range of motion was observed in terminal stance for the hindfoot relative to the tibia in the transversal plane. Subsequently range of motion in the forefoot in preswing was increased. This resulted in less eversion in the hindfoot during midstance, increased internal rotation of the hindfoot during terminal stance and more supination in the forefoot during preswing in the MTP1 arthrodesis group. Motion of the hallux was restricted in the loading response (i.e. plantar flexion) and terminal stance (i.e. dorsiflexion).

As hypothesized, both the ankle and the forefoot are responsible for compensation after MTP1 arthrodesis, because arthrodesis causes less eversion and increased internal rotation of the hindfoot and increased supination of the forefoot. As expected, both dorsiflexion and plantar flexion of the hallux was restricted due to arthrodesis. These findings suggest a gait pattern in which the lateral arch of the foot is more loaded and the stiff hallux is avoided during the stance phase of gait.

Our results indicate that proper motion of the forefoot and ankle joint is important when considering arthrodesis of the MTP1 joint. Therefore, we emphasize careful assessment the range of motion in the forefoot and ankle joint in the pre-operative situation, since patients with a decreased range of motion in the forefoot and ankle joint have a less functioning compensation mechanism. We currently perform a study to evaluate the strength of the positive correlation between the pre-operative range of motion in the forefoot and ankle joint and the clinical outcome.

Purpose: Two questions arise after metatarsophalangeal hallux arthrodesis: what are the 3D changes observed when walking on flat ground ? and is the arthrodesis compensation essentially at the talocrural or interphalangeal level ?

Material and methods: Our series included twelve patients (ten women and two men) mean age 60.7 years. Nine patients had unilateral arthrodesis and three bilateral arthrodesis. The optoelectronic exploration was conducted barefoot. The patients wore underclothes and 27 reflectors. A miniaturised reflector was placed on the distal end of each hallux. Three valid recordings were made.

Results: General gait parameters and kinematic and kinetic values were unchanged (excepting nonsignificant maximal ankle dorsiflexion). On the arthrodesis side we observed: significant decline in propulsion force in the anteroposterior and vertical planes; significantly later heel lift-off; systematic anterior displacement of the ground reaction force of the metatarsophalangeal joint (not seen on the healthy side).

Discussion: We propose a coherent explanation of these observations. The kinetics of balance movement under the head of the first metatarsal head is changed. When the foot is flat on the ground, as the ankle balance movement occurs, the weight of the body is transferred earlier and massively to the forefoot. While in the healthy foot this occurs under the metatarsophalangeal joint of the great toe, in arthrodesis patients body weight is transferred under the interphalangeal joint of the great toe. The balance movement of the interphalangeal joint of the great toe occurs when the ankle balance movement is terminated. The centre of the balance movement is more distal and heel lift-off tends to occur later. During the propulsion phase, the greater lever arm limits the propulsion force, explaining the lesser peak force observed on the arthrodesis side. Use of reflectors on the distal end of the hallux demonstrated that the arthrodesis compensation occurs essentially at the interphalangeal level, exposing this joint to greater risk of degeneration.

The gait pattern of five amputees was recorded by visual observation and also by a quantitative measurement system. The results were compared with the gait pattern predicted from biomechanical analysis. Visual observation was found to be an unreliable clinical skill. The observers recorded only 22.2% of the predicted gait deviations and were unable to comment on 15.6% of all the required observations. The gait parameters which were difficult to assess visually, namely step length and step time, are considered by most workers to be of particular value as diagnostic clinical indicators in gait assessment. The measurement system used was accurate in recording gait deviations and picked up 3.4 times as many deviations as visual observation. This report demonstrates the inadequacy of visual observation as a diagnostic method and emphasises the need for measurements.

Aims. A retrospective longitudinal study was conducted to compare directly volumetric wear of retrieved polyethylene inserts to predicted volumetric wear modelled from individual gait mechanics of total knee arthroplasty (TKA) patients. Methods. In total, 11 retrieved polyethylene tibial inserts were matched with gait analysis testing performed on those patients. Volumetric wear on the articular surfaces was measured using a laser coordinate measure machine and autonomous reconstruction. Knee kinematics and kinetics from individual gait trials drove computational models to calculate medial and lateral tibiofemoral contact paths and forces. Sliding distance along the contact path, normal forces and implantation time were used as inputs to Archard’s equation of wear to predict volumetric wear from gait mechanics. Measured and modelled wear were compared for each component. Results. Volumetric wear rates on eight non-delaminated components measured 15.9 mm. 3. /year (standard error (SE) ± 7.7) on the total part, 11.4 mm. 3. /year (SE ± 6.4) on the medial side and 4.4 (SE ± 2.6) mm. 3. /year on the lateral side. Volumetric wear rates modelled from patient gait mechanics predicted 16.4 mm. 3. /year (SE 2.4) on the total part, 11.7 mm. 3. /year (SE 2.1) on the medial side and 4.7 mm. 3. /year (SE 0.4) on the lateral side. Measured and modelled wear volumes correlated significantly on the total part (p = 0.017) and the medial side (p = 0.012) but not on the lateral side (p = 0.154). Conclusion. In the absence of delamination, patient-specific knee mechanics during gait directly affect wear of the tibial component in TKA. Cite this article: Bone Joint J 2020;102-B(6 Supple A):129–137

This study compared the outcome of total knee replacement (TKR) in adult patients with fixed- and mobile-bearing prostheses during the first post-operative year and at five years’ follow-up, using gait parameters as a new objective measure. This double-blind randomised controlled clinical trial included 55 patients with mobile-bearing (n = 26) and fixed-bearing (n = 29) prostheses of the same design, evaluated pre-operatively and post-operatively at six weeks, three months, six months, one year and five years. Each participant undertook two walking trials of 30 m and completed the EuroQol questionnaire, Western Ontario and McMaster Universities osteoarthritis index, Knee Society score, and visual analogue scales for pain and stiffness. Gait analysis was performed using five miniature angular rate sensors mounted on the trunk (sacrum), each thigh and calf. The study population was divided into two groups according to age (≤ 70 years versus > 70 years).

Improvements in most gait parameters at five years’ follow-up were greater for fixed-bearing TKRs in older patients (> 70 years), and greater for mobile-bearing TKRs in younger patients (≤ 70 years). These findings should be confirmed by an extended age controlled study, as the ideal choice of prosthesis might depend on the age of the patient at the time of surgery.

Purpose: Kinematic studies have shown that patients with a total hip arthroplasty (THA) walk with different gait characteristics compared to normal subjects. This abnormal gait might result from difficulties restoring the normal hip anatomy and biomechanics with THA. Surface replacement arthroplasty (SRA) facilitates leg length management and reconstruction of the normal anatomy of the proximal femur, allowing potential improvements in muscle power, proprioception and hip stability compared to THA.

Method: Patients suffering from advanced hip joint disease were randomised to receive an uncemented metal-metal THA or metal-metal SRA. A group of patients from this study were evaluated pre operatively, at 6 months and one year post operatively at a gait laboratory. A VICON system with 8 cameras, platform (AMTI) and surface electromyograph (Motion Lab) were used. Articular and muscle power and work characteristics of the hip, knee and ankle were analysed with different tasks. Postural stability (e.g. distance between the mass centre and pressure centre) in the standing position will serve to differentiate the 2 groups. Other specific tests, such as the hop test, the step test and the TUG test, were performed.

Summary of Results: Thirty randomised patients were evaluated. The results will be presented and discussed.

Discussion: Considering the strong interest of patients and surgeons for the potential functional benefits of surface replacement arthroplasty, it is necessary to determine scientifically how it compares with the standard of care (THA). Patient age, weight, sex and pre operative function have a strong influence on the post operative function. Thus, a prospective randomised study is mandatory to obtain valid results.

Significance: We strongly believe that this subject warrants special attention considering the possible benefits associated with this technique in the young adult with hip osteoarthitis.

Purpose of Study

In children with spastic diplegia, surgery for equinus has a high incidence of both over and under correction. We wished to determine if conservative (mainly Zone 1) surgery for equinus gait, in the context of multilevel surgery, could result in the avoidance of calcaneus and crouch gait as well as an acceptable rate of recurrent equinus, at medium term follow-up.

Aims. The aim of this study was to assess the functional gain achieved following hip resurfacing arthroplasty (HRA). Patients and Methods. A total of 28 patients (23 male, five female; mean age, 56 years (25 to 73)) awaiting Birmingham HRA volunteered for this prospective gait study, with an age-matched control group of 26 healthy adults (16 male, ten female; mean age, 56 years (33 to 84)). The Oxford Hip Score (OHS) and gait analysis using an instrumented treadmill were used preoperatively and more than two years postoperatively to measure the functional change attributable to the intervention. Results. The mean OHS improved significantly from 27 to 46 points (p < 0.001) at a mean of 29 months (12 to 60) after HRA. The mean metal ion levels at a mean 32 months (13 to 60) postoperatively were 1.71 (0.77 to 4.83) µg/l (ppb) and 1.77 (0.68 to 4.16) µg/l (ppb) for cobalt and chromium, respectively. When compared with healthy controls, preoperative patients overloaded the contralateral good hip, limping significantly. After HRA, patients walked at high speeds, with symmetrical gait, statistically indistinguishable from healthy controls over almost all characteristics. The control group could only be distinguished by an increased push-off force at higher speeds, which may reflect the operative approach. Conclusion. Patients undergoing HRA improved their preoperative gait pattern of a significant limp to a symmetrical gait at high speeds and on inclines, almost indistinguishable from normal controls. HRA with an approved device offers substantial functional gains, almost indistinguishable from healthy controls. Cite this article: Bone Joint J 2019;101-B:1423–1430

Purpose: Currently, clubfoot is initially treated with non-operative methods including Ponseti casting and the French physical therapy program (PT). Our purpose was to evaluate the function of children treated with these techniques.

Methods: Seventy-six idiopathic clubfoot patients were enrolled. Successful non-operative outcomes were achieved in 32 patients (44 feet) treated with casting and 44 patients (66 feet) treated by PT. Initial Dimeglio scores were 10–17. At average age 2.3 years (1.9–3.3yr), subjects’ gait was evaluated with a VICON 512 motion analysis system. Cadence and kinematic data was classified as abnormal if it fell outside of one standard deviation from normal.

Results: No statistical differences for cadence parameters were found between the two groups. Two kinematic patterns were identified: Children treated with PT walked with knee hyperextension (41% of feet)*, equinus (17%)*, and foot-drop (28%)*; whereas zero casted patients walked in equinus and only one demonstrated foot-drop. In contrast, the casted group demonstrated increased stance dorsiflexion (47%)* and calcaneus (18%). More PT feet had increased internal foot progression angle (34% vs. 13%)* and increased shank-based foot rotation (56% vs. 33%)*. Both groups had equal rates of normal sagittal-plane ankle motion (59% PT vs. 55%). [*p< 0.05].

Conclusions: Half of the two year-old patients treated non-operatively for clubfoot had normal sagittal-plane ankle motion. Less than 20% in each group experienced calcaneus and equinus gaits, respectively. These differences may be the result of performing percutaneous tendo Achilles lengthening as part of the Ponseti casting technique, but not as part of the PT program.

The purpose of this study was to investigate whether a gender-specific high-flexion posterior-stabilised (PS) total knee replacement (TKR) would offer advantages over a high-flex PS TKR regarding range of movement (ROM), ‘feel’ of the knee, pain and satisfaction, as well as during activity. A total of 24 female patients with bilateral osteoarthritis entered this prospective, blind randomised trial in which they received a high-flex PS TKR in one knee and a gender-specific high-flexion PS TKR in the other knee. At follow-up, patients were assessed clinically measuring ROM, and questioned about pain, satisfaction and daily ‘feel’ of each knee. Patients underwent gait analysis pre-operatively and at one year, which yielded kinematic, kinetic and temporospatial parameters indicative of knee function during gait. At final follow-up we found no statistically significant differences in ROM (p = 0.82). The median pain score was 0 (0 to 8) in both groups (p = 0.95). The median satisfaction score was 9 (4 to 10) in the high-flex group and 8 (0 to 10) in the gender-specific group (p = 0.98). The median ‘feel’ score was 9 (3 to 10) in the high-flex group and 8 (0 to 10) in the gender-specific group (p = 0.66). Gait analysis showed no statistically significant differences between the two prosthetic designs in any kinematic, kinetic or temporospatial parameters. Both designs produced good clinical results with significant improvements in several gait parameters without evidence of any advantage in the gender-specific design

Purpose: To compare gait kinematics and kinetics in five-year old children treated initially with Ponseti casting versus French physical therapy. A third group, consisting of patients initially treated with these non-operative methods and then undergoing surgery consisting of more than a tendoachilles lengthening, was compared to those children treated entirely non-operatively.

Method: Ninety patients (125 clubfeet) were tested at age five years. Thirty-four feet had undergone only Ponseti treatment, 40 the French program, and 51 had initial non-operative treatment with either the Ponseti or French protocols but later had surgery at an average age of 2+3 years. Kinematics and kinetics were compared to age-matched normal subjects.

Results: Average stance-phase dorsiflexion did not differ between groups or from normal. Incidence of equinus: French 5%, Ponseti 0%; Increased stance-phase dorsiflexion: French 3%, Ponseti 24%, Surgical 18% (p < 0.05). A similar number of feet that were not operated upon at age five had in-toeing: 30% French, 32% Ponseti. Decreased ankle power generation at push-off: 53% French; 47% Ponseti; 67% Surgical. Average ankle power generation: 2.21 W/kg French, 2.36 W/kg Ponseti, 1.97 W/kg Surgical (2.83 W/kg in normal 5-year-old children). There was a difference in ankle power generation between normal feet and both the French and surgical groups (p< 0.001). Feet in the non-operative groups that had undergone Achilles tenotomy (n=28) had similar ankle power to those feet (n=42) that did not have tenotomies (p =0.223). Hip power generation was increased 33% in children who had undergone Ponseti treatment (1.38 W/kg), and 41% after French nonoperative treatment (1.47 W/kg), compared to normal (1.04 W/kg). This may be to compensate for poor ankle push-off.

Conclusion: The gait characteristics of those feet that have not had surgery reveal that the majority had normal ankle kinematics, but reduced efficiency is demonstrated by reduced ankle push-off power, regardless of whether or not an Achilles tenotomy was performed. Decreased ankle power and persistant internal rotation are more frequently seen in feet that have undergone surgery despite initial nonoperative treatment, compared to those treated only by either the Ponseti protocol or the French physical therapy program.

Aims. A flexed knee gait is common in patients with bilateral spastic cerebral palsy and occurs with increased age. There is a risk for the recurrence of a flexed knee gait when treated in childhood, and the aim of this study was to investigate whether multilevel procedures might also be undertaken in adulthood. Patients and Methods. At a mean of 22.9 months (standard deviation 12.9), after single event multi level surgery, 3D gait analysis was undertaken pre- and post-operatively for 37 adult patients with bilateral cerebral palsy and a fixed knee gait. Results. There was a significant improvement of indices and clinical and kinematic parameters including extension of the hip and knee, reduction of knee flexion at initial contact, reduction of minimum and mean knee flexion in the stance phase of gait, improved range of movement of the knee and a reduction of mean flexion of the hip in the stance phase. Genu recurvatum occurred in two patients (n = 3 legs, 4%) and an increase of pelvic tilt (> 5°) was found in 12 patients (n = 23 legs, 31%). Conclusion. Adult patients with bilateral cerebral palsy and a flexed knee gait benefit from multilevel surgery including hamstring lengthening. The risk of the occurence of genu recurvatum and increased pelvic tilt is lower than has been previously reported in children. Cite this article: Bone Joint J 2017;99-B:1256–64

Introduction: There has been an increasing use of orthotic knee braces in the management of knee injuries. To ensure the biomechanics of the knee are not adversely affected, it is important that orthotic knee braces accurately provide the desired angle of immobilisation. The objective of our study was to measure the actual knee flexion angles for a lockable orthotic knee brace, and measure the resulting knee flexion moment.

Materials and methods: Eight healthy male volunteers participated in the study looking at six different types of knee immobilisation: locked in 0, 10, 20, 30 degrees of knee flexion, with the brace unlocked, and without a brace. Force and 3-dimensional motion data were collected using a single Kistler force plate and an eight-camera Qualisys ProReflex motion analysis system.

Results: The kinematic knee flexion angles were significantly different when compared with the angles set at the orthotic knee brace for 0 degrees (p=0.001) and 10 degrees (p=0.011). The kinematic knee flexion angle when no brace was used was significantly different from the angle for the unlocked orthotic knee brace (p= 0.003). The knee flexion moment was directly proportional to the knee flexion angle. There was a statistically significant difference between the knee flexion moment for the six types of immobilisation (p< 0.001).

Discussion: The knee flexion angles measured using the kinematic data did not always correspond with the angle set at the orthotic knee brace. These findings highlight inadequacies in the design of lockable orthotic knee braces, especially at low flexion angles of 0 and 10 degrees. The resulting higher actual knee flexion angles were associated with greater knee flexion moments and joint reaction forces at the tibiofemoral and patellofemoral joints. This can, at best result in increased energy expenditure and decreased agility, and at worse potentially augment injuries to the knee.

Introduction

There is limited evidence assessing the effect of the Ankle Foot Orthosis (AFO) on gait improvements in diplegic cerebral palsy. In particular, the effect of the AFO on vertical forces during gait has not been reported. Appropriate vertical ground reaction forces are crucial in enabling children with CP to walk efficiently. This study investigated the effect of AFO application on the vertical forces in gait, particularly the second vertical peak in force (FZ2) in late stance. The force data was compared with the barefoot walk.

There are nearly no studies which describe the influence of the ileotibial tract (IT) on force distribution in the knee joint in a qunatitative manner. Therfore the aim of this work was to develop a complex 3-D computer model of the lower extremity, consisting of bones, joints and muscle models describing their dynamic behaviour including a special IT model. The computer model provided the possibility to simlate training of the muscular system.

Thus the computer model provided among others the possibility to simulate training of the lateral thigh muscles and vastus lateralis with the aim to tension the IT, with the option to calculate force distribution in the knee and compare it with the effect of a tibial osteotomy.

Patients with varus knees were examined. Kinematic data during walking together with forceplate and EMG data wer collected, before and after tibial osteotomy. The anatomy of the patients was recorded by MRI.

Gait and MRI data were the input in the new developed three dimensional computer model. The scaled geometrical data by Delp (1990) and the MRI data were combined to represent the individuals anatomy.

The model of the lower extremity included 43 muscles with origins/insertions and force-length properties described by Delp (1990). The muscle model was improved by including force-velocity properties and a new muscle tendon parameter (tendon stiffness). A functional scaling method was developed to fit the muscle models to individual anatomy. The IT complex was modelled as a coupled unit of IT, tensor fascia latae and gluteus maximus. Muscle and joint forces were determined using an optimization approach minimizing the cube of the sum of muscle forces divided by their upper bounds.

Simulated muscle training of the lateral thigh muscles and vastus lateralis led to an increased tensioning of the IT. As a result the lateral knee force raised considerably similar to the increase after osteotomy. However the decrease in the medial compartment was small and not comparable with the effect of a valgus osteotomy. Tensioning of the IT leads apparently to an overall larger resulting knee force stabilizing the joint, but is not able to reduce medial knee force to an extent that can avoid osteotomy.

The aim of this study was to examine the loading of the other joints of the lower limb in patients with unilateral osteoarthritis (OA) of the knee. We recruited 20 patients with no other symptoms or deformity in the lower limbs from a consecutive cohort of patients awaiting knee replacement. Gait analysis and electromyographic recordings were performed to determine moments at both knees and hips, and contraction patterns in the medial and lateral quadriceps and hamstrings bilaterally. The speed of gait was reduced in the group with OA compared with the controls, but there were only minor differences in stance times between the limbs. Patients with OA of the knee had significant increases in adduction moment impulse at both knees and the contralateral hip (adjusted p-values: affected knee: p < 0.01, unaffected knee p = 0.048, contralateral hip p = 0.03), and significantly increased muscular co-contraction bilaterally compared with controls (all comparisons for co-contraction, p < 0.01). The other major weight-bearing joints are at risk from abnormal biomechanics in patients with unilateral OA of the knee. Cite this article: Bone Joint J 2013;95-B:348–53

Although equinus gait is the most common abnormality in children with spastic cerebral palsy (CP) there is no consistency in recommendations for treatment, and evidence for best practice is lacking. The Baumann procedure allows selective fractional lengthening of the gastrocnemii and soleus muscles but the long-term outcome is not known. We followed a group of 18 children (21 limbs) with diplegic CP for ten years using three-dimensional instrumented gait analysis. The kinematic parameters of the ankle joint improved significantly following this procedure and were maintained until the end of follow-up. We observed a normalisation of the timing of the key kinematic and kinetic parameters, and an increase in the maximum generation of power of the ankle. There was a low rate of overcorrection (9.5%, n = 2), and a rate of recurrent equinus similar to that found with other techniques (23.8%, n = 5).

As the procedure does not impair the muscle architecture, and allows for selective correction of the contracted gastrocnemii and soleus, it may be recommended as the preferred method for correction of a mild fixed equinus deformity.

This prospective randomised controlled double-blind trial compared two types of PFC Sigma total knee replacement (TKR), differing in three design features aimed at improving flexion. The outcome of a standard fixed-bearing posterior cruciate ligament-preserving design (FB-S) was compared with that of a high-flexion rotating-platform posterior-stabilised design (RP-F) at one year after TKR.

The study group of 77 patients with osteoarthritis of the knee comprised 37 men and 40 women, with a mean age of 69 years (44.9 to 84.9). The patients were randomly allocated either to the FB-S or the RP-F group and assessed pre-operatively and at one year post-operatively. The mean post-operative non-weight-bearing flexion was 107° (95% confidence interval (CI) 104° to 110°)) for the FB-S group and 113° (95% CI 109° to 117°) for the RP-F group, and this difference was statistically significant (p = 0.032). However, weight-bearing range of movement during both level walking and ascending a slope as measured during flexible electrogoniometry was a mean of 4° lower in the RP-F group than in the FB-S group, with 58° (95% CI 56° to 60°) versus 54° (95% CI 51° to 57°) for level walking (p = 0.019) and 56° (95% CI 54° to 58°) versus 52° (95% CI 48° to 56°) for ascending a slope (p = 0.044). Further, the mean post-operative pain score of the Western Ontario and McMaster Universities Osteoarthritis Index was significantly higher in the RP-F group (2.5 (95% CI 1.5 to 3.5) versus 4.2 (95% CI 2.9 to 5.5), p = 0.043).

Although the RP-F group achieved higher non-weight-bearing knee flexion, patients in this group did not use this during activities of daily living and reported more pain one year after surgery.

Introduction. Limb deformity is usually assessed clinically assisted by long leg alignment radiographs and further imaging modalities (MRI and CT). Often decisions are made based on static imaging and simple gait interpretation in clinic. We have assessed the value of gait lab analysis in surgical decision making comparing surgical planning pre and post gait lab assessment. Materials & Methods. Patients were identified from the local limb reconstruction database. Patients were reviewed in the outpatient clinic and long leg alignment radiographs and a CT rotational limb profile were performed. A surgical plan was formulated and documented. All patients then underwent a formal gait lab analysis. The gait lab recommendations were then compared to the initial plan. Results. Twelve patients (8 female) with mean age of 14 (range 12–16) were identified. Nine were developmental torsional malalignments, one arthrogryposis, one hemiparesis secondary to spinal tumour resection and one syndromic limb deficiency. The gait lab recommended conservative management in four patients and agreed with eight surgical plans with one osteotomy level changing. Five patients are post-operative: two bilateral distal tibial osteotomies, two de-rotational femoral osteotomy with de-rotational tibial osteotomies and one bilateral femoral de-rotational osteotomies. Conclusions. Limb deformity correction is major surgery with long rehabilitation and recovery period. Gait lab analysis can identify who would benefit from conservative management rather than surgery with our study showing changes to surgical planning in one third of patients. The gait lab analysis helps to identify patients with functional and neuromuscular imbalances where correcting the bony anatomy may not actually benefit the patient

Vacuum orthoses are being applied in the care of patients with foot and lower leg conditions, as ankle fractures or sprains. The lower leg is protected and immobilized, which increases mobility. Due to the design, the orthoses lead to a difference in leg length, i.e. the side with the orthosis becomes longer, which changes the gait kinematics. To prevent or mitigate the unfavourable effects of altered gait kinematics, leg length-evening devices (shoe lifts) are offered that are worn under the shoe on the healthy side. Our aim was to evaluate the effect of such a device on the normality of gait kinematics. Gait analysis was conducted with 63 adult, healthy volunteers having signed an informed consent form that were asked to walk on a treadmill at a speed of 4.5km/h in three different conditions:. barefoot - as reference for establishing the normality score baseline. with a vacuum orthosis (VACOPed, OPED GmbH, Germany) and a sport shoe. with a vacuum orthosis and a shoe lift (EVENup, OPED GmbH, Germany). Data was sampled using the gait analysis system MCU 200 (LaiTronic GmbH, Austria). The positions of the joint markers were exported from the software and evaluated for the joint angles during the gait cycle using custom software (implemented in DIAdem 2017, National Instruments). A normality score using a modification of the Gait Profile Score (GPS) was calculated in every 1%-interval of the gait cycle and evaluated with a Wilcoxon signed rank test. The GPS value was reduced by 0.33° (0.66°) (median and IQR) while wearing the shoe lift. The effect was statistically significant, and very large (W = 1535.00, p < .001; r (rank biserial) = 0.52, 95% CI [0.29, 0.70]). The significant reduction of the GPS value indicates a more normal gait kinematics while using the leg length-evening device on the contralateral shoe. This rather simple and inexpensive device thus might improve patient comfort and balance while using the vacuum orthoses

Aims. The aim of this study was to compare any differences in the primary outcome (biphasic flexion knee moment during gait) of robotic arm-assisted bi-unicompartmental knee arthroplasty (bi-UKA) with conventional mechanically aligned total knee arthroplasty (TKA) at one year post-surgery. Methods. A total of 76 patients (34 bi-UKA and 42 TKA patients) were analyzed in a prospective, single-centre, randomized controlled trial. Flat ground shod gait analysis was performed preoperatively and one year postoperatively. Knee flexion moment was calculated from motion capture markers and force plates. The same setup determined proprioception outcomes during a joint position sense test and one-leg standing. Surgery allocation, surgeon, and secondary outcomes were analyzed for prediction of the primary outcome from a binary regression model. Results. Both interventions were shown to be effective treatment options, with no significant differences shown between interventions for the primary outcome of this study (18/35 (51.4%) biphasic TKA patients vs 20/31 (64.5%) biphasic bi-UKA patients; p = 0.558). All outcomes were compared to an age-matched, healthy cohort that outperformed both groups, indicating residual deficits exists following surgery. Logistic regression analysis of primary outcome with secondary outcomes indicated that the most significant predictor of postoperative biphasic knee moments was preoperative knee moment profile and trochlear degradation (Outerbridge) (R. 2. = 0.381; p = 0.002, p = 0.046). A separate regression of alignment against primary outcome indicated significant bi-UKA femoral and tibial axial alignment (R. 2. = 0.352; p = 0.029), and TKA femoral sagittal alignment (R. 2. = 0.252; p = 0.016). The bi-UKA group showed a significant increased ability in the proprioceptive joint position test, but no difference was found in more dynamic testing of proprioception. Conclusion. Robotic arm-assisted bi-UKA demonstrated equivalence to TKA in achieving a biphasic gait pattern after surgery for osteoarthritis of the knee. Both treatments are successful at improving gait, but both leave the patients with a functional limitation that is not present in healthy age-matched controls. Cite this article: Bone Joint J 2022;103-B(4):433–443

Aims. This study investigates the effects of intra-articular injection of adipose-derived mesenchymal stem cells (AdMSCs) and platelet-rich plasma (PRP) on lameness, pain, and quality of life in osteoarthritic canine patients. Methods. With informed owner consent, adipose tissue collected from adult dogs diagnosed with degenerative joint disease was enzymatically digested and cultured to passage 1. A small portion of cells (n = 4) surplus to clinical need were characterized using flow cytometry and tri-lineage differentiation. The impact and degree of osteoarthritis (OA) was assessed using the Liverpool Osteoarthritis in Dogs (LOAD) score, Modified Canine Osteoarthritis Staging Tool (mCOAST), kinetic gait analysis, and diagnostic imaging. Overall, 28 joints (25 dogs) were injected with autologous AdMSCs and PRP. The patients were followed up at two, four, eight, 12, and 24 weeks. Data were analyzed using two related-samples Wilcoxon signed-rank or Mann-Whitney U tests with statistical significance set at p < 0.05. Results. AdMSCs demonstrated stem cell-like characteristics. LOAD scores were significantly lower at week 4 compared with preinjection (p = 0.021). The mCOAST improved significantly after three months (p = 0.001) and six months (p = 0.001). Asymmmetry indices decreased from four weeks post-injection and remained significantly lower at six months (p = 0.025). Conclusion. These improvements in quality of life, reduction in pain on examination, and improved symmetry in dogs injected with AdMSCs and PRP support the effectiveness of this combined treatment for symptom modification in canine OA for six months. Cite this article: Bone Joint Res 2021;10(10):650–658

Reports of improved functional outcome of Metal on Metal Hip Resurfacing Arthroplasty (mHRA) to Total Hip Replacement needs to be balanced with concerns of metal ion release. By removing cobalt-chrome, cHRA reduces these risks. To the author's knowledge, there is no data available on functional outcomes of cHRA, therefore the aim of the study was to compare the function between cHRA patients and mHRA patients. 24 patients received a unilateral cHRA (H1, Embody) and was compared to 24 age and gender matched patients with a unilateral mHRA (BHR, Smith and Nephew). All patients completed the Oxford Hip Score (OHS)[T2] and underwent gait analysis on an instrumented treadmill before and at a mean of 74wks (+/− 10) for mHRA and 53wks (+/− 2) for cHRA post op. Walking trials started at 4km/h and increased in 0.5km/h increments until a top walking speed (TWS) was achieved. Vertical ground reaction forces (GRF) were recorded along with the symmetry index (SI). Spatiotemporal measures of gait were also recorded. Vertical GRF were captured for the entire normalised stance phase using statistical parametric mapping (SPM; CI = 95%). The gain in OHS was similar: H1 (25-46), BHR(27-47). TWS increased by 19% with H1 (6.02 – 8.0km/hr), and 20% with BHR (6.02 – 7.37km/hr). SPM of the entire gait cycle illustrated the restoration of symmetry in both groups with no difference in GRF across the stance phase between groups at 5km/hr pre-op and post-op. At faster speeds (6.5km/hr), H1 patients had a mid-support GRF slightly closer to normal compared to BHR. Both groups increased step length similar from pre to post op (H1:0.76 – 0.85cm, BHR:0.77-0.86cm). In this study, subjective and objective functional outcome measures suggest that short term functional outcomes of ceramic resurfacing is not inferior to metal resurfacing

This study aimed to quantify self-reported outcomes and walking gait biomechanics in patients following primary and revision THA. The specific goals of this study were to investigate: (i) if primary and revision THA patients have comparable preoperative outcomes; and (2) if revision THA patients have worse postoperative outcomes than primary THA patients. Forty-three patients undergoing primary THA for osteoarthritis and 23 patients undergoing revision THA were recruited and followed longitudinally for their first 12 postoperative months. Reasons for revision were loosening (73%), dislocation (9%), and infection (18%). Patients completed the Hip dysfunction and Osteoarthritis Outcome Score (HOOS), and underwent gait analysis preoperatively, and at 3 and 12 months postoperatively. A 10 camera motion analysis system (V5 Vantage, Vicon, UK) recorded marker trajectories (100 Hz) during walking at self- selected speeds. A generic lower-body musculoskeletal model (Gait2392) was scaled using principal component analysis [1] and the inverse kinematics tool in Opensim 3.3 was used to compute joint angles for the lower limbs in the sagittal plane. Independent samples t-test were used to compare patient reported outcomes between the primary and revision groups at each timepoint. Statistical parametric mapping was used to compare gait patterns between the two groups at each timepoint. Preoperatively, patients undergoing primary THA reported significantly worse pain (p<0.001), symptoms (p<0.001), function (p<0.001), and quality of life (p=0.004). No differences were observed at 3 and 12 months postoperatively between patients who had received a primary or revision THA. The only observed difference in gait pattern was that patients with a revision THA had reduced hip extension at 3 months, but no differences were observed preoperatively and 12 months. Despite the suggestions in the literature that revision THA is bound to have worse outcomes compared to primary THA, we found no differences in in patient-reported outcomes and gait patterns at 12 months postoperatively. This suggests that it may be possible, in some circumstances, for patients following revision THA to achieve similar outcomes to their peers undergoing primary THA

In 2010, we published results of Ponseti versus primary posteromedial release (PMR) for congenital talipes equinovarus (CTEV) in 51 prospective patients. This study reports outcomes at a median of 15 years from original treatment. We followed 51 patients at a median of 15 years (range 13–17 years) following treatment of CTEV with either Ponseti method (25 patients; 38 feet) or PMR (26 patients; 42 feet). Thirty-eight patientsd were contacted and 33 participated in clinical review (65%), comprising patient reported outcomes, clinical examination, 3-D gait analysis and plantar pressures. Sixteen of 38 Ponseti treated feet (42%) and 20 of 42 PMR treated feet (48%) had undergone further surgery. The PMR treated feet were more likely to have osteotomies and intra- articular surgeries (16 vs 5 feet, p<0.05). Of the 33 patients reviewed with multimodal assessment, the Ponseti group demonstrated better scores on the Dimeglio (5.8 vs 7.0, p<0.05), the Disease Specific Instrument (80 vs 65.6, p<0.05), the Functional Disability Inventory (1.1 vs 5.0, p<0.05) and the AAOS Foot & Ankle Questionnaire (52.2 vs. 46.6, p < 0.05), as well as improved total sagittal ankle range of motion in gait, ankle plantarflexion range at toe off and calf power generation. The primary PMR group displayed higher lateral midfoot and forefoot pressures. Whilst numbers of repeat surgical interventions following Ponseti treatment and primary PMR were similar, the PMR treated feet had greater numbers of osteotomies and intra-articular surgeries. Outcomes were improved at a median of 15 years for functional data for the Ponseti method versus PMR, with advantages seen in the Ponseti group over several domains. This study provides the most comprehensive evaluation of outcomes close to skeletal maturity in prospective cohorts, reinforcing the Ponseti Method as the initial treatment of choice for idiopathic clubfeet

Wearable inertial sensors can detect abnormal gait associated with knee or hip osteoarthritis (OA). However, few studies have compared sensor-derived gait parameters between patients with hip and knee OA or evaluated the efficacy of sensors suitable for remote monitoring in distinguishing between the two. Hence, our study seeks to examine the differences in accelerations captured by low-frequency wearable sensors in patients with knee and hip OA and classify their gait patterns. We included patients with unilateral hip and knee OA. Gait analysis was conducted using an accelerometer ipsilateral with the affected joint on the lateral distal thighs. Statistical parametric mapping (SPM) was used to compare acceleration signals. The k-Nearest Neighbor (k-NN) algorithm was trained on 80% of the signals' Fourier coefficients and validated on the remaining 20% using 10-fold cross-validation to classify the gait patterns into hip and knee OA. We included 42 hip OA patients (19 females, age 70 [63–78], BMI of 28.3 [24.8–30.9]) and 59 knee OA patients (31 females, age 68 [62–74], BMI of 29.7 [26.3–32.6]). The SPM results indicated that one cluster (12–20%) along the vertical axis had accelerations exceeding the critical threshold of 2.956 (p=0.024). For the anteroposterior axis, three clusters were observed exceeding the threshold of 3.031 at 5–19% (p = 0.0001), 39–54% (p=0.00005), and 88–96% (p = 0.01). Regarding the mediolateral axis, four clusters were identified exceeding the threshold of 2.875 at 0–9% (p = 0.02), 14–20% (p=0.04), 28–68% (p < 0.00001), and 84–100% (p = 0.004). The k-NN model achieved an AUC of 0.79, an accuracy of 80%, and a precision of 85%. In conclusion, the Fourier coefficients of the signals recorded by wearable sensors can effectively discriminate the gait patterns of knee and hip OA. In addition, the most remarkable differences in the time domain were observed along the mediolateral axis

The effects of Hypericum perforatum on nerve regeneration after sciatic nerve injury have not yet been evaluated in all its aspects yet. In this experimental study, the effect of Hypericum perforatum on injured nerve tissue was histologically and biochemically investigated. Motor functional healing was surveyed by gait analysis. Rats were divided into 3 groups: Group I (n=8) was intact control group and no intervention and treatment was applied to this group. Group II (n=16) was surgical control group and Group III (n=16) was Hypericum perforatum group. After the operation, while any treatment was performed on Group II, 30 mg/kg dose Hypericum perforatum extract was intraperitoneally administered to the Group III per day for 8 weeks from the 1. st. day of post-op. Gait analysis was made to all rats for functional evaluation at 2. nd. , 3. rd. , 4. th. , 6. th. and 8. th. weeks, and sciatic functional index (SFI) was evaluated. At the end of the eighth week, sciatic nerve tissue samples were taken from the sacrificed rats. Tissues were examined biochemically, histologically and immnohistochemically. Malondialdehyde (MDA) as an indicator of oxidative stress and main antioxidant enzyme [superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT)] levels were biochemically measured. The nerve degeneration and regeneration were histologically viewed, and also cell count was immnohistochemically done by having done anti-S100 staining. It was seen that measurement results of SFI were statistically significantly difference between groups (p<0,001). In the sciatic nerve tissue samples taken from the rats, it was not determined a statistically significant difference between MDA, SOD, GPx and CAT levels detected by ELISA method (p>0,05). In the histological evaluation, it was seen that Hypericum perforatum affected positively the regeneration and immunohistochemically, it was found a statistically significant difference between the anti-S-100 positive cell numbers. The obtained results in this study show that; Hypericum perforatum, which was intraperitoneally administered on rats subjected to nerve injury, has affected positively the nerve regeneration and it can also provide an insight to future studies

The tendency towards using inertial sensors for remote monitoring of the patients at home is increasing. One of the most important characteristics of the sensors is sampling rate. Higher sampling rate results in higher resolution of the sampled signal and lower amount of noise. However, higher sampling frequency comes with a cost. The main aim of our study was to determine the validity of measurements performed by low sampling frequency (12.5 Hz) accelerometers (SENS) in patients with knee osteoarthritis compared to standard sensor-based motion capture system (Xsens). We also determined the test-retest reliability of SENS accelerometers. Participants were patients with unilateral knee osteoarthritis. Gait analysis was performed simultaneously by using Xsens and SENS sensors during two repetitions of over-ground walking at a self-selected speed. Gait data from Xsens were used as an input for AnyBody musculoskeletal modeling software to measure the accelerations at the exact location of two defined virtual sensors in the model (VirtualSENS). After preprocessing, the signals from SENS and VirtualSENS were compared in different coordinate axes in time and frequency domains. ICC for SENS data from first and second trials were calculated to assess the repeatability of the measurements. We included 32 patients (18 females) with median age 70.1[48.1 – 85.4]. Mean height and weight of the patients were 173.2 ± 9.6 cm and 84.2 ± 14.7 kg respectively. The correlation between accelerations in time domain measured by SENS and VirtualSENS in different axes was r = 0.94 in y-axis (anteroposterior), r = 0.91 in x-axis (vertical), r = 0.83 in z-axis (mediolateral), and r = 0.89 for the magnitude vector. In frequency domain, the value and the power of fundamental frequencies (F. 0. ) of SENS and VirtualSENS signals demonstrated strong correlation (r = 0.98 and r = 0.99 respectively). The result of test-retest evaluation showed excellent repeatability for acceleration measurement by SENS sensors. ICC was between 0.89 to 0.94 for different coordinate axes. Low sampling frequency accelerometers can provide valid and reliable measurements especially for home monitoring of the patients, in which handling big data and sensors cost and battery lifetime are among important issues

For clinical movement analysis, optical marker-based motion capture is the gold standard. With the advancement of AI-driven computer vision, markerless motion capture (MMC) has emerged. Validity against the marker-based standard has only been examined for lightly-dressed subjects as required for marker placement. This pilot study investigates how different clothing affects the measurement of typical gait metrics. Gait tests at self-selected speed (4 km/h) were performed on a treadmill (Motek Grail), captured by 9 cameras (Qualisys Miqus, 720p, f=100Hz) and analyzed by a leading MMC application (Theia, Canada). A healthy subject (female, h=164cm, m=54kg) donned clothes between trials starting from lightly dressed (LD: bicycle tight, short-sleeved shirt), adding a short skirt (SS: hip occlusion) or a midi-skirt (MS: partial knee occlusion) or street wear (SW: jeans covering ankle, long-sleeved blouse), the lattern combined with a short jacket (SWJ) or a long coat (SWC). Gait parameters (mean±SD, t=10s) calculated (left leg, mid-stance) were ankle pronation (AP-M), knee flexion (KF-M), pelvic obliquity (PO-M) and trunk lateral lean (TL-M) representing clinically common metrics, different joints and anatomic planes. Four repetitions of the base style (LD) were compared to states of increased garment coverage using the t-test (Bonferroni correction). For most gait metrics, differences between the light dress (LD) and various clothing styles were absent (p>0.0175), small (< 2SD) or below the minimal clinically important differences (MCID). For instance, KF-M was for LD=10.5°±1.7 versus MD=12.0°±0.5 (p=0.07) despite partial knee cover. AP-M measured for LD=5.2°±0.6 versus SW=4.1°±0.7 (p<0.01) despite ankle cover-up. The difference for KF-M between LD=10.5°±1.7 versus SWL=6.0°±0.9, SW and SWJ (7.6°±1.5, p<0.01) indicates more intra-subject gait variability than clothing effect. This study suggests that typical clothings styles only have a small clinically possibly negligible effect on common gait parameters measured with MMC. Thus, patients may not need to change clothes or be instructed to wear specific garments. In addition to avoiding marker placement, this further increases speed, ease and economy of clinical gait analysis with MMC facilitating high volume or routine application

Aims. To compare changes in gait kinematics and walking speed 24 months after conventional (C-MLS) and minimally invasive (MI-MLS) multilevel surgery for children with diplegic cerebral palsy (CP). Methods. A retrospective analysis of 19 children following C-MLS, with mean age at surgery of 12 years five months (seven years ten months to 15 years 11 months), and 36 children following MI-MLS, with mean age at surgery of ten years seven months (seven years one month to 14 years ten months), was performed. The Gait Profile Score (GPS) and walking speed were collected preoperatively and six, 12 and 24 months postoperatively. Type and frequency of procedures as part of MLS, surgical adverse events, and subsequent surgery were recorded. Results. In both groups, GPS improved from the preoperative gait analysis to the six-month assessment with maintenance at 12 and 24 months postoperatively. While reduced at six months in both groups, walking speed returned to preoperative speed by 12 months. The overall pattern of change in GPS and walking speed was similar over time following C-MLS and MI-MLS. There was a median of ten procedures per child as part of both C-MLS (interquartile range (IQR) 8.0 to 11.0) and MI-MLS (IQR 7.8 to 11.0). Surgical adverse events occurred in seven (37%) and 13 (36%) children, with four (21%) and 13 (36%) patients requiring subsequent surgery following C-MLS and MI-MLS, respectively. Conclusion. This study indicates similar improvements in gait kinematics and walking speed 24 months after C-MLS and MI-MLS for children with diplegic CP. Cite this article: Bone Joint J 2021;103-B(1):192–197

Introduction and Objective. In recent studies, robotic-assisted surgical techniques for unicompartmental knee arthroplasty (UKA) have demonstrated superior implant positioning and limb alignment compared to a conventional technique. However, the impact of the robotic-assisted technique on clinical and functional outcomes is less clear. The aim of this study was to compare the gait parameters of UKA performed with conventional and image-free robotic-assisted techniques. Materials and Methods. This prospective, single center study included 66 medial UKA, randomized to a robotic-assisted (n=33) or conventional technique (n=33). Gait analysis was performed on a treadmill at 6 months to identify changes in gait characteristics (walking speed, each degree-of-freedom: flexion–extension, abduction–adduction, internal-external rotation and anterior-posterior displacement). Clinical results were assessed at 6 months using the IKS score and the Forgotten Joint Score. Implants position was assessed on post-operative radiographs. Results. Post-operatively, the whole gait cycle was not significantly different between groups. In both groups there was a significant improvement in varus deformity between the pre- and post-operative gait cycle. There was no significant difference between the two groups in clinical scores, implant position, revision and complication rates. Conclusions. No difference of gait parameters could be identified between medial UKA performed with image-free robotic-assisted technique or with conventional technique

Aims. The most effective surgical approach for total hip arthroplasty (THA) remains controversial. The direct anterior approach may be associated with a reduced risk of dislocation, faster recovery, reduced pain and fewer surgical complications. This systematic review aims to evaluate the current evidence for the use of this approach in THA. Materials and Methods. Following the Cochrane collaboration, an extensive literature search of PubMed, Medline, Embase and OvidSP was conducted. Randomised controlled trials, comparative studies, and cohort studies were included. Outcomes included the length of the incision, blood loss, operating time, length of stay, complications, and gait analysis. Results. A total of 42 studies met the inclusion criteria. Most were of medium to low quality. There was no difference between the direct anterior, anterolateral or posterior approaches with regards to length of stay and gait analysis. Papers comparing the length of the incision found similar lengths compared with the lateral approach, and conflicting results when comparing the direct anterior and posterior approaches. . Most studies found the mean operating time to be significantly longer when the direct anterior approach was used, with a steep learning curve reported by many. Many authors used validated scores including the Harris hip score, and the Western Ontario and McMaster Universities Arthritis Index. These mean scores were better following the use of the direct anterior approach for the first six weeks post-operatively. Subsequently there was no difference between these scores and those for the posterior approach. Conclusion . There is little evidence for improved kinematics or better long-term outcomes following the use of the direct anterior approach for THA. There is a steep learning curve with similar rates of complications, length of stay and outcomes. . Well-designed, multi-centre, prospective randomised controlled trials are required to provide evidence as to whether the direct anterior approach is better than the lateral or posterior approaches when undertaking THA. Cite this article: Bone JointJ 2017;99-B:732–40