We describe the influence of the angle of immobilisation during partial weight-bearing on the forces across the extensor mechanism of the knee. Gait analysis was performed on eight healthy male subjects with the right knee in an orthotic brace locked at 0°, 10°, 20° and 30°, with the brace unlocked and also without a brace. The ground
An experimental sheep model was used for impaction allografting of 12 hemiarthroplasty femoral components placed into two equal-sized groups. In group 1, a 50:50 mixture of ApaPore hydroxyapatite bone-graft substitute and allograft was used. In group 2, ApaPore and allograft were mixed in a 90:10 ratio. Both groups were killed at six months. Ground
We used an in vivo model to assess the use of an autogenous cancellous bone block and marrow graft for augmenting tendon reattachment to metallic implants. We hypothesised that augmentation of the tendon-implant interface with a bone block would enable retention of the graft on the implant surface, enhance biological integration, and result in more consistent functional outcomes compared with previously reported morcellised graft augmentation techniques. A significant improvement in functional weight-bearing was observed between six and 12 weeks. The significant increase in ground
Aims. To compare the gait of unicompartmental knee arthroplasty (UKA)
and total knee arthroplasty (TKA) patients with healthy controls,
using a machine-learning approach. Patients and Methods. 145 participants (121 healthy controls, 12 patients with cruciate-retaining
TKA, and 12 with mobile-bearing medial UKA) were recruited. The
TKA and UKA patients were a minimum of 12 months post-operative,
and matched for pattern and severity of arthrosis, age, and body
mass index. . Participants walked on an instrumented treadmill until their
maximum walking speed was reached. Temporospatial gait parameters,
and vertical ground
This study investigates the use of porous biphasic ceramics as graft extenders in impaction grafting of the femur during revision hip surgery. Impaction grafting of the femur was performed in four groups of sheep. Group one received pure allograft, group two 50% allograft and 50% BoneSave, group three 50% allograft and 50% BoneSave type 2 and group four 10% allograft and 90% BoneSave as the graft material. Function was assessed using an index of pre- and post-operative peak vertical ground
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. 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.Aims
Methods
Registry studies on modified acetabular polyethylene (PE) liner designs are limited. We investigated the influence of standard and modified PE acetabular liner designs on the revision rate for mechanical complications in primary cementless total hip arthroplasty (THA). We analyzed 151,096 primary cementless THAs from the German Arthroplasty Registry (EPRD) between November 2012 and November 2020. Cumulative incidence of revision for mechanical complications for standard and four modified PE liners (lipped, offset, angulated/offset, and angulated) was determined using competing risk analysis at one and seven years. Confounders were investigated with a Cox proportional-hazards model.Aims
Methods
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. 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.Aims
Methods
Adverse local tissue reactions associated with abnormal wear considerably slowed down the general use of metal-on-metal (MoM) hip resurfacing arthroplasty (HRA), now limited to a few specialized centres. In this study, we provide the clinical results of 400 consecutive MoM HRAs implanted more than 20 years ago in one such centre. A total of 355 patients (400 hips) were treated with Conserve Plus HRA between November 1996 and November 2000. There were 96 female (27%) and 259 male patients (73%). Their mean age was 48.2 years (SD 10.9). The University of California, Los Angeles (UCLA) hip scores and 12-item Short Form Survey (SF-12) quality of life scores were reported. Survivorship was assessed using Kaplan-Meier analyses.Aims
Methods
The aim of this study was to compare robotic arm-assisted bi-unicompartmental knee arthroplasty (bi-UKA) with conventional mechanically aligned total knee arthroplasty (TKA) in order to determine the changes in the anatomy of the knee and alignment of the lower limb following surgery. An analysis of 38 patients who underwent TKA and 32 who underwent bi-UKA was performed as a secondary study from a prospective, single-centre, randomized controlled trial. CT imaging was used to measure coronal, sagittal, and axial alignment of the knee preoperatively and at three months postoperatively to determine changes in anatomy that had occurred as a result of the surgery. The hip-knee-ankle angle (HKAA) was also measured to identify any differences between the two groups.Aims
Methods
The aim of this study was to assess the functional gain achieved following hip resurfacing arthroplasty (HRA). 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.Aims
Patients and Methods
The purpose of this study was to explore the correlation between femoral torsion and morphology of the distal femoral condyle in patients with trochlear dysplasia and lateral patellar instability. A total of 90 patients (64 female, 26 male; mean age 22.1 years (SD 7.2)) with lateral patellar dislocation and trochlear dysplasia who were awaiting surgical treatment between January 2015 and June 2019 were retrospectively analyzed. All patients underwent CT scans of the lower limb to assess the femoral torsion and morphology of the distal femur. The femoral torsion at various levels was assessed using the a) femoral anteversion angle (FAA), b) proximal and distal anteversion angle, c) angle of the proximal femoral axis-anatomical epicondylar axis (PFA-AEA), and d) angle of the AEA–posterior condylar line (AEA-PCL). Representative measurements of distal condylar length were taken and parameters using the ratios of the bianterior condyle, biposterior condyle, bicondyle, anterolateral condyle, and anteromedial condyle were calculated and correlated with reference to the AEA, using the Pearson Correlation coefficient.Aims
Methods
A borderline dysplastic hip can behave as either stable or unstable and this makes surgical decision making challenging. While an unstable hip may be best treated by acetabular reorientation, stable hips can be treated arthroscopically. Several imaging parameters can help to identify the appropriate treatment, including the Femoro-Epiphyseal Acetabular Roof (FEAR) index, measured on plain radiographs. The aim of this study was to assess the reliability and the sensitivity of FEAR index on MRI compared with its radiological measurement. The technique of measuring the FEAR index on MRI was defined and its reliability validated. A retrospective study assessed three groups of 20 patients: an unstable group of ‘borderline dysplastic hips’ with lateral centre edge angle (LCEA) less than 25° treated successfully by periacetabular osteotomy; a stable group of ‘borderline dysplastic hips’ with LCEA less than 25° treated successfully by impingement surgery; and an asymptomatic control group with LCEA between 25° and 35°. The following measurements were performed on both standardized radiographs and on MRI: LCEA, acetabular index, femoral anteversion, and FEAR index.Aims
Patients and Methods
We compared implant and patient survival following intraoperative periprosthetic femoral fractures (IOPFFs) during primary total hip arthroplasty (THA) with matched controls. This retrospective cohort study compared 4831 hips with IOPFF and 48 154 propensity score matched primary THAs without IOPFF implanted between 2004 and 2016, which had been recorded on a national joint registry. Implant and patient survival rates were compared between groups using Cox regression.Aims
Patients and Methods
There is little information about how to manage patients with a recurvatum deformity of the distal tibia and osteoarthritis (OA) of the ankle. The aim of this study was to evaluate the functional and radiological outcome of addressing this deformity using a flexion osteotomy and to assess the progression of OA after this procedure. A total of 39 patients (12 women, 27 men; mean age 47 years (28 to 72)) with a distal tibial recurvatum deformity were treated with a flexion osteotomy, between 2010 and 2015. Nine patients (23%) subsequently required conversion to either a total ankle arthroplasty (seven) or an arthrodesis (two) after a mean of 21 months (9 to 36). A total of 30 patients (77%), with a mean follow-up of 30 months (24 to 76), remained for further evaluation. Functional outcome, sagittal ankle joint OA using a modified Kellgren and Lawrence Score, tibial lateral surface (TLS) angle, and talar offset ratio (TOR) were evaluated on pre- and postoperative weight-bearing radiographs.Aims
Patients and Methods
A contact patch to rim (CPR) distance of <
10 mm has been
associated with edge-loading and excessive wear. However, not all
arthroplasties with a low CPR distance show problems with wear.
Therefore, CPR distance may not be the only variable affecting the
post-operative metal ion concentrations. We used multiple logistic regression to determine what variables
differed between the patients who had high and low cobalt (CoS)
and chromium (CrS) serum ion concentrations within a cohort of patients
with low (<
10 mm) CPR distances. A total of 56 patients treated
with unilateral hip resurfacing arthroplasty (HRA) had CoS and CrS
ion studies performed more than one year after surgery. The mean
age of the patients at the time of surgery was 51.7 years (29 to
70), with 38 women (68%) and 18 men (32%).Aims
Patients and Methods
The hip’s capsular ligaments passively restrain extreme range of movement (ROM) by wrapping around the native femoral head/neck. We determined the effect of hip resurfacing arthroplasty (HRA), dual-mobility total hip arthroplasty (DM-THA), conventional THA, and surgical approach on ligament function. Eight paired cadaveric hip joints were skeletonized but retained the hip capsule. Capsular ROM restraint during controlled internal rotation (IR) and external rotation (ER) was measured before and after HRA, DM-THA, and conventional THA, with a posterior (right hips) and anterior capsulotomy (left hips).Aims
Materials and Methods
The outcome of total knee arthroplasty (TKA) is not always satisfactory.
The purpose of this study was to identify satisfaction and biomechanical
features characterising the gait of patients who had undergone TKA
with either an anatomical single radius design or a medial pivot
design. We hypothesised that the latter would provide superior function. This is a study of a subset of patients recruited into a prospective
randomised study of a single radius design Aims
Patients and Methods
The eccentric glenosphere was principally introduced into reverse
shoulder arthroplasty to reduce the incidence of scapular notching.
There is only limited information about the influence of its design
on deltoid power and joint reaction forces. The aim of our study was to investigate how the diameter and
eccentricity of the glenosphere affect the biomechanics of the deltoid
and the resultant joint reaction forces. Different sizes of glenosphere and eccentricity were serially
tested in ten cadaveric shoulders using a custom shoulder movement
simulator.Aims
Methods
Patellar instability most frequently presents
during adolescence. Congenital and infantile dislocation of the
patella is a distinct entity from adolescent instability and measurable
abnormalities may be present at birth. In the normal patellofemoral
joint an increase in quadriceps angle and patellar height are matched
by an increase in trochlear depth as the joint matures. Adolescent
instability may herald a lifelong condition leading to chronic disability
and arthritis. Restoring normal anatomy by trochleoplasty, tibial tubercle transfer
or medial patellofemoral ligament (MPFL) reconstruction in the young
adult prevents further instability. Although these techniques are
proven in the young adult, they may cause growth arrest and deformity
where the physis is open. A vigorous non-operative strategy may
permit delay of surgery until growth is complete. Where non-operative
treatment has failed a modified MPFL reconstruction may be performed
to maintain stability until physeal closure permits anatomical reconstruction.
If significant growth remains an extraosseous reconstruction of
the MPFL may impart the lowest risk to the physis. If minor growth
remains image intensifier guided placement of femoral intraosseous
fixation may impart a small, but acceptable, risk to the physis. This paper presents and discusses the literature relating to
adolescent instability and provides a framework for management of
these patients. Cite this article: