Secondary fracture healing is strongly influenced by the stiffness of the bone-fixator system. Biomechanical tests are extensively used to investigate stiffness and strength of fixation devices. The stiffness values reported in the literature for locked plating, however, vary by three orders of magnitude. The aim of this study was to examine the influence that the method of restraint and load application has on the stiffness produced, the strain distribution within the bone, and the stresses in the implant for locking plate constructs. Synthetic composite bones were used to evaluate experimentally the influence of four different methods of loading and restraining specimens, all used in recent previous studies. Two plate types and three screw arrangements were also evaluated for each loading scenario. Computational models were also developed and validated using the experimental tests.Objectives
Methods
Whilst gait speed is variable between healthy and injured adults, the extent to which speed alone alters the 3D A total of 26 men and 25 women (18 to 35 years old) participated in this study. Participants walked on a treadmill with the KneeKG system at a slow imposed speed (2 km/hr) for three trials, then at a self-selected comfortable walking speed for another three trials. Paired Objectives
Methods
A new method of vascularised tibial grafting
has been developed for the treatment of avascular necrosis (AVN)
of the talus and secondary osteoarthritis (OA) of the ankle. We
used 40 cadavers to identify the vascular anatomy of the distal
tibia in order to establish how to elevate a vascularised tibial
graft safely. Between 2008 and 2012, eight patients (three male,
five female, mean age 50 years; 26 to 68) with isolated AVN of the
talus and 12 patients (four male, eight female, mean age 58 years;
23 to 76) with secondary OA underwent vascularised bone grafting
from the distal tibia either to revascularise the talus or for arthrodesis.
The radiological and clinical outcomes were evaluated at a mean
follow-up of 31 months (24 to 62). The peri-malleolar arterial arch
was confirmed in the cadaveric study. A vascularised bone graft
could be elevated safely using the peri-malleolar pedicle. The clinical
outcomes for the group with AVN of the talus assessed with the mean
Mazur ankle grading scores, improved significantly from 39 points
(21 to 48) pre-operatively to 81 points (73 to 90) at the final
follow-up (p = 0.01). In all eight revascularisations, bone healing
was obtained without progression to talar collapse, and union was
established in 11 of 12 vascularised arthrodeses at a mean follow-up
of 34 months (24 to 58). MRI showed revascularisation of the talus
in all patients. We conclude that a vascularised tibial graft can be used both
for revascularisation of the talus and for the arthrodesis of the
ankle in patients with OA secondary to AVN of the talus. Cite this article:
The surgical management of ankle arthritis with tibiotalar arthrodesis
is known to alter gait, as compared with normal ankles. The purpose
of this study was to assess post-operative gait function with gait
before arthrodesis. We prospectively studied 20 patients who underwent three-dimensional
gait analysis before and after tibiotalar arthrodesis. Cadence,
step length, walking velocity and total support time were assessed.
Kinetic parameters, including the moment and power of the ankle
in the sagittal plane and hip power were also recorded.Aims
Patients and Methods
Talonavicular and subtalar joint fusion through
a medial incision (modified triple arthrodesis) has become an increasingly
popular technique for treating symptomatic flatfoot deformity caused
by posterior tibial tendon dysfunction. The purpose of this study was to look at its clinical and radiological
mid- to long-term outcomes, including the rates of recurrent flatfoot
deformity, nonunion and avascular necrosis of the dome of the talus. A total of 84 patients (96 feet) with a symptomatic rigid flatfoot
deformity caused by posterior tibial tendon dysfunction were treated
using a modified triple arthrodesis. The mean age of the patients
was 66 years (35 to 85) and the mean follow-up was 4.7 years (1 to 8.3).
Both clinical and radiological outcomes were analysed retrospectively. In 86 of the 95 feet (90.5%) for which radiographs were available,
there was no loss of correction at final follow-up. In all, 14 feet
(14.7%) needed secondary surgery, six for nonunion, two for avascular
necrosis, five for progression of the flatfoot deformity and tibiotalar
arthritis and one because of symptomatic overcorrection. The mean
American Orthopaedic Foot and Ankle Society Hindfoot score (AOFAS
score) at final follow-up was 67 (between 16 and 100) and the mean
visual analogue score for pain 2.4 points (between 0 and 10). In conclusion, modified triple arthrodesis provides reliable
correction of deformity and a good clinical outcome at mid- to long-term
follow-up, with nonunion as the most frequent complication. Avascular
necrosis of the talus is a rare but serious complication of this
technique. Cite this article:
Static radiostereometric analysis (RSA) using implanted markers is considered the most accurate system for the evaluation of prosthesis migration. By using CT bone models instead of markers, combined with a dynamic RSA system, a non-invasive measurement of joint movement is enabled. This method is more accurate than current 3D skin marker-based tracking systems. The purpose of this study was to evaluate the accuracy of the CT model method for measuring knee joint kinematics in static and dynamic RSA using the marker method as the benchmark. Bone models were created from CT scans, and tantalum beads were implanted into the tibia and femur of eight human cadaver knees. Each specimen was secured in a fixture, static and dynamic stereoradiographs were recorded, and the bone models and marker models were fitted to the stereoradiographs.Objectives
Methods
The objective of this study was to assess the association between whole body sagittal balance and risk of falls in elderly patients who have sought treatment for back pain. Balanced spinal sagittal alignment is known to be important for the prevention of falls. However, spinal sagittal imbalance can be markedly compensated by the lower extremities, and whole body sagittal balance including the lower extremities should be assessed to evaluate actual imbalances related to falls. Patients over 70 years old who visited an outpatient clinic for back pain treatment and underwent a standing whole-body radiograph were enrolled. Falls were prospectively assessed for 12 months using a monthly fall diary, and patients were divided into fallers and non-fallers according to the history of falls. Radiological parameters from whole-body radiographs and clinical data were compared between the two groups.Objectives
Methods
To present our experience of using a combination of intra-articular
osteotomy and external fixation to treat different deformities of
the knee. A total of six patients with a mean age of 26.5 years (15 to
50) with an abnormal hemi-joint line convergence angle (HJLCA) and
mechanical axis deviation (MAD) were included. Elevation of a tibial
hemiplateau or femoral condylar advancement was performed and limb
lengthening with correction of residual deformity using a circular
or monolateral Ilizarov frame.Aims
Patients and Methods
Normal sagittal spine-pelvis-lower extremity alignment is crucial in humans for maintaining an ergonomic upright standing posture, and pathogenesis in any segment leads to poor balance. The present study aimed to investigate how this sagittal alignment can be affected by severe knee osteoarthritis (KOA), and whether associated changes corresponded with symptoms of lower back pain (LBP) in this patient population. Lateral radiograph films in an upright standing position were obtained from 59 patients with severe KOA and 58 asymptomatic controls free from KOA. Sagittal alignment of the spine, pelvis, hip and proximal femur was quantified by measuring several radiographic parameters. Global balance was accessed according to the relative position of the C7 plumb line to the sacrum and femoral heads. The presence of chronic LBP was documented. Comparisons between the two groups were carried by independent samples Objectives
Methods
This prospective cohort study aims to determine if the size of
the tendon gap following acute rupture of the Achilles tendon shows
an association with the functional outcome following non-operative
treatment. All patients presenting within two weeks of an acute unilateral
rupture of the Achilles tendon between July 2012 and July 2015 were
considered for the study. In total, 38 patients (nine female, 29
male, mean age 52 years; 29 to 78) completed the study. Dynamic
ultrasound examination was performed to confirm the diagnosis and
measure the gap between ruptured tendon ends. Outcome was assessed
using dynamometric testing of plantarflexion and the Achilles tendon
Total Rupture score (ATRS) six months after the completion of a
rehabilitation programme.Aims
Patients and Methods
This retrospective cohort study compared the results of vascularised
and non-vascularised anterior sliding tibial grafts for the treatment
of osteoarthritis (OA)of the ankle secondary to osteonecrosis of
the talus. We reviewed the clinical and radiological outcomes of 27 patients
who underwent arthrodesis with either vascularised or non-vascularised
(conventional) grafts, comparing the outcomes (clinical scores,
proportion with successful union and time to union) between the
two groups. The clinical outcome was assessed using the Mazur and
American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot
scores. The mean follow-up was 35 months (24 to 68).Aims
Patients and Methods
The aim of the current study was to analyse the effects of posterior cruciate ligament (PCL) deficiency on forces of the posterolateral corner structure and on tibiofemoral (TF) and patellofemoral (PF) contact force under dynamic-loading conditions. A subject-specific knee model was validated using a passive flexion experiment, electromyography data, muscle activation, and previous experimental studies. The simulation was performed on the musculoskeletal models with and without PCL deficiency using a novel force-dependent kinematics method under gait- and squat-loading conditions, followed by probabilistic analysis for material uncertain to be considered.Objectives
Methods
The purpose of this study was to compare the results and complications of tibial lengthening over an intramedullary nail with treatment using the traditional Ilizarov method. In this matched case study, 16 adult patients underwent 19 tibial lengthening over nails (LON) procedures. For the matched case group, 17 patients who underwent 19 Ilizarov tibial lengthenings were retrospectively matched to the LON group.Objectives
Methods
The purpose of this study was to investigate the prevalence of
sarcopenia and to examine its impact on patients with degenerative
lumbar spinal stenosis (DLSS). This case-control study included two groups: one group consisting
of patients with DLSS and a second group of control subjects without
low back or neck pain and related leg pain. Five control cases were
randomly selected and matched by age and gender (n = 77 cases and
n = 385 controls) for each DLSS case. Appendicular muscle mass,
hand-grip strength, sit-to-stand test, timed up and go (TUG) test,
and clinical outcomes, including the Oswestry Disability Index (ODI)
scores and the EuroQol EQ-5D were compared between the two groups.Aims
Patients and Methods
The main object of this study was to use a geometric morphometric
approach to quantify the left-right symmetry of talus bones. Analysis was carried out using CT scan images of 11 pairs of
intact tali. Two important geometric parameters, volume and surface
area, were quantified for left and right talus bones. The geometric
shape variations between the right and left talus bones were also
measured using deviation analysis. Furthermore, location of asymmetry
in the geometric shapes were identified. Numerical results showed that talus bones are bilaterally symmetrical
in nature, and the difference between the surface area of the left
and right talus bones was less than 7.5%. Similarly, the difference
in the volume of both bones was less than 7.5%. Results of the three-dimensional
(3D) deviation analyses demonstrated the mean deviation between
left and right talus bones were in the range of -0.74 mm to 0.62
mm. It was observed that in eight of 11 subjects, the deviation
in symmetry occurred in regions that are clinically less important
during talus surgery. Objective
Methods
Results
There is increasing evidence that flexible flatfoot (FF) can
lead to symptoms and impairment in health-related quality of life.
As such we undertook an observational study investigating the aetiology
of this condition, to help inform management. The hypothesis was
that as well as increased body mass index (BMI) and increased flexibility of
the lower limb, an absent anterior subtalar articulation would be
associated with a flatter foot posture. A total of 84 children aged between eight and 15 years old were
prospectively recruited. The BMI for each child was calculated,
flexibility was assessed using the lower limb assessment scale (LLAS)
and foot posture was quantified using the arch height index (AHI).
Each child underwent a sagittal T1-weighted MRI scan of at least
one foot. Aims
Patients and Methods
