Aims. The aim of this study was to examine the real time in
vivo
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
Hip arthroplasty aims to accurately recreate joint biomechanics. Considerable attention has been paid to vertical and horizontal offset, but femoral head centre in the anteroposterior (AP) plane has received little attention. This study investigates the accuracy of restoration of joint centre of rotation in the AP plane. Postoperative CT scans of 40 patients who underwent unilateral uncemented total hip arthroplasty were analyzed. Anteroposterior offset (APO) and femoral anteversion were measured on both the operated and non-operated sides. Sagittal tilt of the femoral stem was also measured. APO measured on axial slices was defined as the perpendicular distance between a line drawn from the anterior most point of the proximal femur (anterior reference line) to the centre of the femoral head. The anterior reference line was made parallel to the posterior condylar axis of the knee to correct for rotation.Aims
Methods
The cemented Oxford unicompartmental knee arthroplasty (OUKA) features two variants: single and twin peg OUKA. The purpose of this study was to assess the stability of both variants in a worst-case scenario of bone defects and suboptimal cementation. Single and twin pegs were implanted randomly allocated in 12 pairs of human fresh-frozen femora. We generated 5° bone defects at the posterior condyle. Relative movement was simulated using a servohydraulic pulser, and analyzed at 70°/115° knee flexion. Relative movement was surveyed at seven points of measurement on implant and bone, using an optic system.Aims
Methods
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
Objectives. Many studies have investigated the
This annotation considers the place of extra-articular
reconstruction in the treatment of anterior cruciate ligament (ACL)
deficiency. Extra-articular reconstruction has been employed over
the last century to address ACL deficiency. However, the technique
has not gained favour, primarily due to residual instability and
the subsequent development of degenerative changes in the lateral
compartment of the knee. Thus intra-articular reconstruction has
become the technique of choice. However, intra-articular reconstruction
does not restore normal knee
The cause of dissatisfaction following total
knee arthroplasty (TKA) remains elusive. Much attention has been
focused on static mechanical alignment as a basis for surgical success and
optimising outcomes. More recently, research on both normal and
osteoarthritic knees, as well as
This study compares the initial outcomes of minimally invasive techniques for single-event multi-level surgery with conventional single-event multi-level surgery. The minimally invasive techniques included derotation osteotomies using closed corticotomy and fixation with titanium elastic nails and percutaneous lengthening of muscles where possible. A prospective cohort study of two matched groups was undertaken. Ten children with diplegic cerebral palsy with a mean age of ten years six months (7.11 to 13.9) had multi-level minimally invasive surgery and were matched for ambulatory level and compared with ten children with a mean age of 11 years four months (7.9 to 14.4) who had conventional single-event multi-level surgery. Gait
We performed a prospective, randomised trial of 44 patients to compare the functional outcomes of a posterior-cruciate-ligament-retaining and posterior-cruciate-ligament-substituting total knee arthroplasty, and to gain a better understanding of the in vivo
Aims. Long-term clinical outcomes for ceramic-on-ceramic (CoC) bearings
are encouraging. However, there is a risk of squeaking. Guidelines
for the orientation of the acetabular component are defined from
static imaging, but the position of the pelvis and thus the acetabular
component during activities associated with edge-loading are likely
to be very different from those measured when the patient is supine.
We assessed the functional orientation of the acetabular component. Patients and Methods. A total of 18 patients with reproducible squeaking in their CoC
hips during deep flexion were investigated with a control group
of 36 non-squeaking CoC hips. The two groups were matched for the
type of implant, the orientation of the acetabular component when
supine, the size of the femoral head, ligament laxity, maximum hip
flexion and body mass index. . Results. The mean functional anteversion of the acetabular component at
the point when patients initiated rising from a seated position
was significantly less in the squeaking group than in the control
group, 8.1° (-10.5° to 36.0°) and 21.1° (-1.9° to 38.4°) respectively
(p = 0.002). . Conclusion. The functional orientation of the acetabular component during
activities associated with posterior edge-loading are different
from those measured when supine due to patient-specific pelvic
There has been a marked increase in the number of hip arthroscopies performed over the past 16 years, primarily in the management of femoroacetabular impingement (FAI). Insights into the pathoanatomy of FAI, and high-level evidence supporting the clinical effectiveness of arthroscopy in the management of FAI, have fuelled this trend. Arthroscopic management of labral tears with repair may have superior results compared with debridement, and there is now emerging evidence to support reconstructive options where repair is not possible. In situations where an interportal capsulotomy is performed to facilitate access, data now support closure of the capsule in selective cases where there is an increased risk of postoperative instability. Preoperative planning is an integral component of bony corrective surgery in FAI, and this has evolved to include computer-planned resection. However, the benefit of this remains controversial. Hip instability is now widely accepted, and diagnostic criteria and treatment are becoming increasingly refined. Instability can also be present with FAI or develop as a result of FAI treatment. In this annotation, we outline major current controversies relating to decision-making in hip arthroscopy for FAI. Cite this article:
Aims. 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. Patients and Methods. 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. Results. Significant improvement was recorded across numerous parameters
compared with pre-operative measurements. Temporal-spatial data
demonstrated a significant increase in step length (p = 0.003) and
velocity (p = <
0.001). Total support time decreased for the
unaffected limb (p = 0.01).
Dislocation following total hip arthroplasty (THA) is a well-known and potentially devastating complication. Clinicians have used many strategies in attempts to prevent dislocation since the introduction of THA. While the importance of postoperative care cannot be ignored, particular emphasis has been placed on preoperative planning in the prevention of dislocation. The strategies have progressed from more traditional approaches, including modular implants, the size of the femoral head, and augmentation of the offset, to newer concepts, including patient-specific component positioning combined with computer navigation, robotics, and the use of dual-mobility implants. As clinicians continue to pursue improved outcomes and reduced complications, these concepts will lay the foundation for future innovation in THA and ultimately improved outcomes. Cite this article:
It is unknown whether gap laxities measured in robotic arm-assisted total knee arthroplasty (TKA) correlate to load sensor measurements. The aim of this study was to determine whether symmetry of the maximum medial and lateral gaps in extension and flexion was predictive of knee balance in extension and flexion respectively using different maximum thresholds of intercompartmental load difference (ICLD) to define balance. A prospective cohort study of 165 patients undergoing functionally-aligned TKA was performed (176 TKAs). With trial components in situ, medial and lateral extension and flexion gaps were measured using robotic navigation while applying valgus and varus forces. The ICLD between medial and lateral compartments was measured in extension and flexion with the load sensor. The null hypothesis was that stressed gap symmetry would not correlate directly with sensor-defined soft tissue balance.Aims
Methods
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. Bi-UKA subjects (n = 22) were measured on an instrumented treadmill, using standard gait metrics, at top walking speeds. Age-, sex-, and BMI-matched healthy (n = 24) and primary TKA (n = 22) subjects formed control groups. TKA subjects with preoperative patellofemoral or tricompartmental arthritis or ACL dysfunction were excluded. The Oxford Knee Score (OKS) and EuroQol five-dimension questionnaire (EQ-5D) were compared. Bi-UKA, then TKA, were performed on eight fresh frozen cadaveric knees, to investigate knee extensor efficiency under controlled laboratory conditions, using a repeated measures study design.Aims
Methods