Aims

Functional alignment (FA) in total knee arthroplasty (TKA) aims to achieve balanced gaps by adjusting implant positioning while minimizing changes to constitutional joint line obliquity (JLO). Although FA uses kinematic alignment (KA) as a starting point, the final implant positions can vary significantly between these two approaches. This study used the Coronal Plane Alignment of the Knee (CPAK) classification to compare differences between KA and final FA positions.

Introduction. Understanding the implications of decreased femoral torsion on gait and running in children and adolescents might help orthopaedic surgeons to optimize treatment decisions. To date, there is limited evidence regarding the kinematic gait deviations between children with decreased femoral torsion and typically developing children as well as regarding the implications of the same on the adaptation of walking to running. Method. A three dimensional gait analysis study was undertaken to compare gait deviations during running and walking among patients with decreased femoral torsion (n=15) and typically developing children (n=11). Linear mixed models were utilized to establish comparisons within and between the two groups and investigate the relation between clinical examination, spatial parameters and the difference in hip rotation between running and walking. Result. Patients exhibited increased external hip rotation during walking in comparison to controls accompanied by higher peaks for the same as well as for, knee valgus and external foot progression angle. A similar kinematic gait pattern was observed during running with significant differences noted in peak knee valgus. In terms of variations from running to walking, patients internally rotated their initially external rotated hip by 4°, whereas controls maintained the same internal hip rotation. Patients and controls displayed comparable kinematic gait deviations during running compared to walking. The passive hip range of motion, torsions and velocity did not notably influence the variation between mean hip rotation from running to walking. Conclusion. This study underlines the potential of 3D gait kinematics to elucidate the functional implications of decreased FT and hence may contribute to clinical decision making

Aims

The aim of this study was to evaluate the suitability of the tapered cone stem in total hip arthroplasty (THA) in patients with excessive femoral anteversion and after femoral osteotomy.

A ceramic-on-ceramic hip resurfacing implant (cHRA) was developed and introduced in an MHRA-approved clinical investigation to provide a non metallic alternative hip resurfacing product. This study aimed to examine function and physical activity levels of patients with a cHRA implant using subjective and objective measures both before and 12 months following surgery in comparison with age and gender matched healthy controls. Eighty-two unilateral cHRA patients consented to this study as part of a larger prospective, non-randomised, clinical investigation. In addition to their patient reported outcome measures (PROMs), self- reported measures of physical activity levels and gait analysis were undertaken both pre- operatively (1.5 weeks) and post operatively (52 weeks). This data was then compared to data from a group of 43 age gender and BMI matched group of healthy controls. Kinetics and kinematics were recorded using an instrumented treadmill and 3D Motion Capture. Statistical parametric mapping was used for analysis. cHRA improved the median Harris Hip Score from 63 to 100, Oxford Hip score from 27 to 48 and the MET from 5.7 to 10.3. cHRA improved top walking speed (5.75km vs 7.27km/hr), achieved a more symmetrical ground reaction force profile, (Symmetry Index value: 10.6% vs 0.9%) and increased hip range of motion (ROM) (31.7° vs 45.9°). Postoperative data was not statistically distinguishable from the healthy controls in any domain. This gait study sought to document the function of a novel ceramic hip resurfacing, using those features of gait commonly used to describe the shortcomings of hip arthroplasty. These features were captured before and 12 months following surgery. Preoperatively the gait patterns were typical for OA patients, while at 1 year postoperatively, this selected group of patients had gait patterns that were hard to distinguish from healthy controls despite an extended posterior approach. Applications for regulatory approval have been submitted

Aims

Children with spinal dysraphism can develop various musculoskeletal deformities, necessitating a range of orthopaedic interventions, causing significant morbidity, and making considerable demands on resources. This systematic review aimed to identify what outcome measures have been reported in the literature for children with spinal dysraphism who undergo orthopaedic interventions involving the lower limbs.

The December 2023 Children’s orthopaedics Roundup³⁶⁰ looks at: A comprehensive nonoperative treatment protocol for developmental dysplasia of the hip in infants; How common are refractures in childhood?; Femoral nailing for paediatric femoral shaft fracture in children aged eight to ten years; Who benefits from allowing the physis to grow in slipped capital femoral epiphysis?; Paediatric patients with an extremity bone tumour: a secondary analysis of the PARITY trial data; Split tibial tendon transfers in cerebral palsy equinovarus foot deformities; Liposomal bupivacaine nerve block: an answer to opioid use?; Correction with distal femoral transphyseal screws in hemiepiphysiodesis for coronal-plane knee deformity.

Aims

To systematically review the efficacy of split tendon transfer surgery on gait-related outcomes for children and adolescents with cerebral palsy (CP) and spastic equinovarus foot deformity.

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.

Aims

Perthes’ disease (PD) often results in femoral head deformity and leg length discrepancy (LLD). Our objective was to analyze femoral morphology in PD patients at skeletal maturity to assess where the LLD originates, and evaluate the effect of contralateral epiphysiodesis for length equalization on proximal and subtrochanteric femoral lengths.

Aims

Bi-unicondylar arthroplasty (Bi-UKA) is a bone and anterior cruciate ligament (ACL)-preserving alternative to total knee arthroplasty (TKA) when the patellofemoral joint is preserved. The aim of this study is to investigate the clinical outcomes and biomechanics of Bi-UKA.

Introduction. Total Hip Arthroplasty (THA) devices are now increasingly subjected to a progressively greater range of kinematic and loading regimes from substantially younger and more active patients. In the interest of ensuring adequate THA solutions for all patient groups, THA polyethylene acetabular liner (PE Liner) wear representative of younger, heavier, and more active patients (referred to as HA in this study) warrants further understanding. Previous studies have investigated HA joint related morbidity [1]. Current or past rugby players are more likely to report osteoarthritis, osteoporosis, and joint replacement than a general population. This investigation aimed to provide a preliminary understanding of HA patient specific PE liner tribological performance during Standard Walking (SW) gait in comparison to IS0:14242-1:2014 standardized testing. Materials and Methods. Nine healthy male subjects volunteered for a gait lab-based study to collect kinematics and loading profiles. Owing to limitations in subject selection, five subjects wore a weighted jacket to increase Body Mass Index ≥30 (BMI). An induced increase in Bodyweight was capped (<30%BW) to avoid significantly effecting gait [3] (mean=11%BW). Six subjects identified as HA per BMI≥30, but with anthropometric ratios indicative of lower body fat as previously detailed by the author [2] (Waist-to-hip circumference ratio and waist circumference-to-height ratio). Three subjects identified as Normal (BMI<25). Instrumented force plate loading profiles were scaled (≈270%BW) in agreement with instrumented hip force data [4]. A previously verified THA (Pinnacle® Marathon® 36×56mm, DePuy Synthes) Finite Element Analysis wear model based on Archard's law and modified time hardening model [5] was used to predict geometrical changes due to wear and deformation, respectively (Figure 1). Subject dependent kinematic and loading conditions were sampled to generate, for both legs, 19 SW simulation runs using a central composite design of response surface method. Results. HA group demonstrated comparable SW gait characteristics and Range of Motion (RoM) to the Normal group (p>0.1) (Figure 2) but statistically greater SW peak loads, PE liner wear rates, deformation, and penetration after 3Mc (Million cycles) of SW (p<0.01). HA group demonstrated comparable RoM (p>0.4) and peak loading to ISO-14242-1:2014 (p>0.1) although, up to 8° increase in flexion-extension angle was observed. The HA group demonstrated statistically greater wear rates (mean 7.5% increase) to ISO-14242-1:2014 (p<0.05) (Figure 3). No difference in PE liner deformation or penetration was observed (p>0.4). Discussion. This study detailed only a 19. th. percentile within a broader HA population (BW=91kg, n=485) [6] however, were statistically worst-case compared to a Normal group and ISO-14242-1:2014. A 95. th. percentile HA population (BW=127kg) may produce lower PE liner tribological performance than reported in this investigation and therefore, warrants further investigation. Further studies would be beneficial to determine whether the increase in PE liner wear rate for HA patients is predictable based on kinematics and loading alone, or whether influences exist in design inputs and surgical factors. Conclusion. The HA population detailed in this study (representative of a 19. th. percentile) demonstrated statistically greater SW PE liner wear rates compared to ISO-14242-1:2014. This study may have implications for the test methods considered appropriate to verify novel designs. For any figures or tables, please contact the authors directly

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).

Aims

The complex relationship between acetabular component position and spinopelvic mobility in patients following total hip arthroplasty (THA) renders it difficult to optimize acetabular component positioning. Mobility of the normal lumbar spine during postural changes results in alterations in pelvic tilt (PT) to maintain the sagittal balance in each posture and, as a consequence, markedly changes the functional component anteversion (FCA). This study aimed to investigate the in vivo association of lumbar degenerative disc disease (DDD) with the PT angle and with FCA during postural changes in THA patients.

Purpose. Patients with acetabular dysplasia demonstrate altered biomechanics during gate and other activities. We hypothesized that these patients exhibit a compensatory increase in the anterior pelvic tilt during gait. Materials & Methods. Twelve patients were included in this prospective radiographic and gait analysis study prior to the PAO. All were women. The mean age was 27 years (+/− 8 yrs). Tonnis grade was zero in nine, and one in three hips. All patients performed multiple one-minute walking trials on the level, the incline, and the decline treadmill surfaces in an optical motion capture lab. Anterior pelvic tilt is reported in (+), while the posterior pelvic tilt is reported in (–) values. Results. Radiographic Data. : The mean alpha angle measured from the Dunn and the frog lateral images was 63.0º±17.4, and 54.7º±16.4, respectively. The mean LCEA was 14.9°±6.1, and the mean anterior center edge angle was 18.3°±8.9. the mean acetabular version at 1, 2, and 3 o'clock were 12.1°±11.6, 29.2°±9.9, and 23.3°±7.4, respectively. Intra-class correlation coefficient (ICC) for these measurements were 0.934, 0.895, and 0.971, respectively. The mean femoral anteversion, as measured on the 3D CT scan was 21.3°±16.1. The mean hip flexion range was 107.1°± 7.2. The mean pelvic tilt was 88.7 mm ± 14.4 using the PS-SI distance with an ICC of 0.998. Gait Data. : Baseline measurements were done in the standing position. On the leveled surface, 5 patients had anterior (+) while 7 had posterior (−) pelvic tilt. The mean posterior pelvic tilt was 1.0° with the range of −2.8° to +0.67°. On the inclined surface, all patients had posterior (−) pelvic tilt. The mean pelvic tilt was −4.9° with the range of −6.4° to −3.1°. On the declined surface, 8 patients had anterior (+) while 4 patients had posterior (−) pelvic tilt. The mean pelvic tilt was −0.39° with the range of −1.9° to +1.0°. The pelvic tilt was negatively correlated with the PS-SI distance on all three surfaces with the Spearman coefficients of −0.27, −0.04, and −0.18 on the 3 different surfaces, respectively. Conclusion. Our results demonstrated that the patients with hip dysplasia exhibit variable degrees of the pelvic tilt while walking on different surface inclinations. Weak negative correlation with the standing pelvic tilt measurements from the radiographs suggests that those patients with more anterior standing pelvic tilt tend to have greater compensatory posterior tilt during gait

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

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

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