Aims. To assess the extent of osteointegration in two designs of shoulder
resurfacing implants. Bony integration to the Copeland cylindrical
central stem design and the Epoca RH conical-crown design were compared. Patients and Methods. Implants retrieved from six patients in each group were pair-matched.
Mean time to revision surgery of Copeland implants was 37 months
(standard deviation (. sd. ) 23; 14 to 72) and Epoca RH 38
months (. sd. 28; 12 to 84). The mean age of patients investigated
was 66 years (. sd. 4; 59 to 71) and 58 years (. sd. 17;
31 to 73) in the Copeland and Epoca RH groups respectively. None
of these implants were revised for loosening. . Results. Increased osteointegration was measured under the cup in the
Copeland implant group with limited bone seen in direct contact
with the central stem. Bone adjacent to the Epoca RH implants was
more uniform. . Conclusion. This difference in the distribution of bone-implant contact and
bone formation was attributed to the Epoca implant’s conical crown,
which is positioned in more dense peripheral bone. The use of a
central stem may not be necessary provided there is adequate peripheral
fixation within good quality humeral bone. Take home message: Poor osteointegration of cementless surface
replacement shoulder prosthesis may be improved by
Aims. Periprosthetic femoral fractures (PFF) following total hip arthroplasty
(THA) are devastating complications that are associated with functional
limitations and increased overall mortality. Although cementless
implants have been associated with an increased risk of PFF, the
precise contribution of implant geometry and design on the risk
of both intra-operative and post-operative PFF remains poorly investigated.
A systematic review was performed to aggregate all of the PFF literature
with specific attention to the femoral implant used. Patients and Methods. A systematic search strategy of several journal databases and
recent proceedings from the American Academy of Orthopaedic Surgeons
was performed. Clinical articles were included for analysis if sufficient
implant description was provided. All articles were reviewed by
two reviewers. A review of fundamental investigations of implant
load-to-failure was performed, with the intent of identifying similar
conclusions from the clinical and fundamental literature. Results. In total 596 articles were initially identified, with 34 being
eligible for analysis. Aggregate analysis of 1691 PFFs in 342 719
primary THAs revealed a significantly higher number of PFFs with
cementless femoral implants (p <
0.001). Single-wedge and double-wedge
(fit-and-fill) femoral implants were associated with a threefold
increase in PFF rates (p <
0.001) compared with anatomical, fully
coated and tapered/rounded stems. Within cemented stems, loaded-taper
(Exeter) stems were associated with more PFFs than composite-beam
(Charnley) stems (p = 0.004). Review of the fundamental literature
revealed very few studies comparing cementless component designs. Conclusion. Very few studies within the PFF literature provide detailed implant
information. Cementless implants, specifically those of single-wedge
and double-wedge, have the highest PFF rates in the literature,
with most investigations recommending against their use in older
patients with osteoporotic bone. This review illustrates the need
for registries and future PFF studies to record implant name and
information for future analysis. Furthermore, future biomechanical
investigations comparing modern implants are needed to clarify the
precise contribution of
This study reports updates the previously published two-year clinical, functional, and radiological results of a group of patients who underwent transfibular total ankle arthroplasty (TAA), with follow-up extended to a minimum of five years. We prospectively evaluated 89 patients who underwent transfibular TAA for end-stage osteoarthritis. Patients’ clinical and radiological examinations were collected pre- and postoperatively at six months and then annually for up to five years of follow-up. Three patients were lost at the final follow-up with a total of 86 patients at the final follow-up.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
There are concerns regarding nail/medullary canal mismatch and initial stability after cephalomedullary nailing in unstable pertrochanteric fractures. This study aimed to investigate the effect of an additional anteroposterior blocking screw on fixation stability in unstable pertrochanteric fracture models with a nail/medullary canal mismatch after short cephalomedullary nail (CMN) fixation. Eight finite element models (FEMs), comprising four different femoral diameters, with and without blocking screws, were constructed, and unstable intertrochanteric fractures fixed with short CMNs were reproduced in all FEMs. Micromotions of distal shaft fragment related to proximal fragment, and stress concentrations at the nail construct were measured.Aims
Methods
The use of hinged implants in primary total knee
replacement (TKR) should be restricted to selected indications and mainly
for elderly patients. Potential indications for a rotating hinge
or pure hinge implant in primary TKR include: collateral ligament
insufficiency, severe varus or valgus deformity (>
20°) with necessary
relevant soft-tissue release, relevant bone loss including insertions
of collateral ligaments, gross flexion-extension gap imbalance,
ankylosis, or hyperlaxity. Although data reported in the literature
are inconsistent, clinical results depend on
Unicompartmental and total knee arthroplasty (UKA and TKA) are successful treatments for osteoarthritis, but the solid metal implants disrupt the natural distribution of stress and strain which can lead to bone loss over time. This generates problems if the implant needs to be revised. This study investigates whether titanium lattice UKA and TKA implants can maintain natural load transfer in the proximal tibia. In a cadaveric model, UKA and TKA procedures were performed on eight fresh-frozen knee specimens, using conventional (solid) and titanium lattice tibial implants. Stress at the bone-implant interfaces were measured and compared to the native knee.Aims
Methods
Highly polished stems with force-closed design have shown satisfactory clinical results despite being related to relatively high early migration. It has been suggested that the minimal thickness of cement mantles surrounding the femoral stem should be 2 mm to 4 mm to avoid aseptic loosening. The line-to-line cementing technique of the femoral stem, designed to achieve stem press-fit, challenges this opinion. We compared the migration of a highly polished stem with force-closed design by standard and line-to-line cementing to investigate whether differences in early migration of the stems occur in a clinical study. In this single-blind, randomized controlled, clinical radiostereometric analysis (RSA) study, the migration pattern of the cemented Corail hip stem was compared between line-to-line and standard cementing in 48 arthroplasties. The primary outcome measure was femoral stem migration in terms of rotation and translation around and along with the X-, Y-, and Z- axes measured using model-based RSA at three, 12, and 24 months. A linear mixed-effects model was used for statistical analysis.Aims
Methods
Stemless humeral implants have been developed to overcome stem-related complications in total shoulder arthroplasty (TSA). However, stemless implant designs may hypothetically result in less stable initial fixation, potentially affecting long-term survival. The aim of this study is to investigate early fixation and migration patterns of the stemless humeral component of the Simpliciti Shoulder System and to evaluate clinical outcomes. In this prospective cohort study, radiostereometric analysis (RSA) radiographs were obtained in 24 patients at one day, six weeks, six months, one year, and two years postoperatively. Migration was calculated using model-based RSA. Clinical outcomes were evaluated using the visual analogue scale (VAS), the Oxford Shoulder Score (OSS), the Constant-Murley Score (CMS), and the Disabilities of the Arm, Shoulder and Hand (DASH) score.Aims
Methods
This systematic review of the literature summarises
the clinical experience with ceramic-on-ceramic hip bearings over
the past 40 years and discusses the concerns that exist in relation
to the bearing combination. Loosening, fracture, liner chipping
on insertion, liner canting and dissociation, edge-loading and squeaking
have all been reported, and the relationship between these issues
and
Anchorage of pedicle screw rod instrumentation in the elderly spine with poor bone quality remains challenging. Our study aims to evaluate how the screw bone anchorage is affected by screw design, bone quality, loading conditions, and cementing techniques. Micro-finite element (µFE) models were created from micro-CT (μCT) scans of vertebrae implanted with two types of pedicle screws (L: Ennovate and R: S4). Simulations were conducted for a 10 mm radius region of interest (ROI) around each screw and for a full vertebra (FV) where different cementing scenarios were simulated around the screw tips. Stiffness was calculated in pull-out and anterior bending loads.Aims
Methods
Varus-valgus constrained (VVC) devices are typically used in revision settings, often with stems to mitigate the risk of aseptic loosening. However, in at least one system, the VVC insert is compatible with the primary posterior-stabilized (PS) femoral component, which may be an option in complex primary situations. We sought to determine the implant survivorship, radiological and clinical outcomes, and complications when this VVC insert was coupled with a PS femur without stems in complex primary total knee arthroplasties (TKAs). Through our institution’s total joint registry, we identified 113 primary TKAs (103 patients) performed between 2007 and 2017 in which a VVC insert was coupled with a standard cemented PS femur without stems. Mean age was 68 years (SD 10), mean BMI was 32 kg/m2 (SD 7), and 59 patients (50%) were male. Mean follow-up was four years (2 to 10).Aims
Methods
DF Hamilton, R Burnett, JT Patton, CR Howie, M Moran, AHRW Simpson, P Gaston.
Acetabular edge-loading was a cause of increased wear rates in metal-on-metal hip arthroplasties, ultimately contributing to their failure. Although such wear patterns have been regularly reported in retrieval analyses, this study aimed to determine their in vivo location and investigate their relationship with acetabular component positioning. 3D CT imaging was combined with a recently validated method of mapping bearing surface wear in retrieved hip implants. The asymmetrical stabilizing fins of Birmingham hip replacements (BHRs) allowed the co-registration of their acetabular wear maps and their computational models, segmented from CT scans. The in vivo location of edge-wear was measured within a standardized coordinate system, defined using the anterior pelvic plane.Aims
Methods
Focal femoral inlay resurfacing has been developed
for the treatment of full-thickness chondral defects of the knee. This
technique involves implanting a defect-sized metallic or ceramic
cap that is anchored to the subchondral bone through a screw or
pin. The use of these experimental caps has been advocated in middle-aged
patients who have failed non-operative methods or biological repair
techniques and are deemed unsuitable for conventional arthroplasty
because of their age. This paper outlines the
This study aims to enhance understanding of clinical and radiological consequences and involved mechanisms that led to corrosion of the Precice Stryde (Stryde) intramedullary lengthening nail in the post market surveillance era of the device. Between 2018 and 2021 more than 2,000 Stryde nails have been implanted worldwide. However, the outcome of treatment with the Stryde system is insufficiently reported. This is a retrospective single-centre study analyzing outcome of 57 consecutive lengthening procedures performed with the Stryde nail at the authors’ institution from February 2019 until November 2020. Macro- and microscopic metallographic analysis of four retrieved nails was conducted. To investigate observed corrosion at telescoping junction, scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDX) were performed.Aims
Methods
