We have used an experimental model employing the bent tail of rats to investigate the effects of
We investigated factors that were thought to be associated with an increased incidence of squeaking of ceramic-on-ceramic total hip replacements. Between June 1997 and December 2008 the three senior authors implanted 2406 primary total hip replacements with a ceramic-on-ceramic bearing surface. The mean follow-up was 10.6 years. The diagnosis was primary osteoarthritis in each case, and no patient had undergone previous surgery to the hip. We identified 74 squeaking hips (73 patients) giving an incidence of 3.1% at a mean follow-up of 9.5 years (4.1 to 13.3). Taller, heavier and younger patients were significantly more likely to have hips that squeaked. Squeaking hips had a significantly higher range of post-operative internal (p = 0.001) and external rotation (p = 0.003) compared with silent hips. Patients with squeaking hips had significantly higher activity levels (p = 0.009). A squeaking hip was not associated with a significant difference in patient satisfaction (p = 0.24) or Harris hip score (p = 0.34). Four implant position factors enabled good prediction of squeaking. These were high acetabular component inclination, high femoral offset, lateralisation of the hip centre and either high or low acetabular component anteversion. This is the largest study to date to examine patient factors and implant position factors that predispose to squeaking of a ceramic-on-ceramic hip. The results suggest that factors which increase the
To investigate the extent of bone development around the scaffold of custom triflange acetabular components (CTACs) over time. We performed a single-centre historical prospective cohort study, including all patients with revision THA using the aMace CTAC between January 2017 and March 2021. A total of 18 patients (18 CTACs) were included. Models of the hemipelvis and the scaffold component of the CTACs were created by segmentation of CT scans. The CT scans were performed immediately postoperatively and at least one year after surgery. The amount of bone in contact with the scaffold was analyzed at both times, and the difference was calculated.Aims
Methods
Ankylosing spondylitis (AS) is a progressive
multisystem chronic inflammatory disorder. The hallmark of this pathological
process is a progressive fusion of the zygapophyseal joints and
disc spaces of the axial skeleton, leading to a rigid kyphotic deformity
and positive sagittal balance. The ankylosed spine is unable to
accommodate normal
To systematically evaluate whether bracing can effectively achieve curve regression in patients with adolescent idiopathic scoliosis (AIS), and to identify any predictors of curve regression after bracing. Two independent reviewers performed a comprehensive literature search in PubMed, Ovid, Web of Science, Scopus, and Cochrane Library to obtain all published information about the effectiveness of bracing in achieving curve regression in AIS patients. Search terms included “brace treatment” or “bracing,” “idiopathic scoliosis,” and “curve regression” or “curve reduction.” Inclusion criteria were studies recruiting patients with AIS undergoing brace treatment and one of the study outcomes must be curve regression or reduction, defined as > 5° reduction in coronal Cobb angle of a major curve upon bracing completion. Exclusion criteria were studies including non-AIS patients, studies not reporting p-value or confidence interval, animal studies, case reports, case series, and systematic reviews. The GRADE approach to assessing quality of evidence was used to evaluate each publication.Aims
Methods
Aseptic loosening of the acetabular component continues to be the most common indication for revision of total hip replacements in younger patients. Early in the evolution of the cemented hip, arthroplasty surgeons switched from removal to retention of the acetabular subchondral bone plate, theorising that unfavourable
Matrix metalloproteinases (MMPs), responsible
for extracellular matrix remodelling and angiogenesis, might play
a major role in the response of the growth plate to detrimental
loads that lead to overuse injuries in young athletes. In order
to test this hypothesis, human growth plate chondrocytes were subjected
to
Surgical reconstruction of deformed Charcot feet carries a high risk of nonunion, metalwork failure, and deformity recurrence. The primary aim of this study was to identify the factors contributing to these complications following hindfoot Charcot reconstructions. We retrospectively analyzed patients who underwent hindfoot Charcot reconstruction with an intramedullary nail between January 2007 and December 2019 in our unit. Patient demographic details, comorbidities, weightbearing status, and postoperative complications were noted. Metalwork breakage, nonunion, deformity recurrence, concurrent midfoot reconstruction, and the measurements related to intramedullary nail were also recorded.Aims
Methods
1. There seem to be two distinct methods of destruction of the foot, once pain sensibility has been lost: the first is a slow erosion and shortening associated with perforating ulcers under the distal weight-bearing end of the foot. The second is a proximal disintegration of the tarsus in which
This study compared the cobalt and chromium serum ion concentration of patients treated with two different metal-on-metal (MoM) hinged total knee arthroplasty (TKA) systems, as well as a titanium nitride (TiN)-coated variant. A total of 63 patients (65 implants) were treated using either a MoM-coated (n = 29) or TiN-coated (n = 7) hinged TKA (GenuX mobile bearing, MUTARS; Implantcast, Germany) versus the BPKS (Brehm, Germany) hinged TKA (n = 27), in which the weight placed on the MoM hinge is diffused through a polyethylene (PE) inlay, reducing the direct load on the MoM hinge. Serum cobalt and chromium ion concentrations were assessed after minimum follow-up of 12 months, as well as functional outcome and quality of life.Aims
Methods
This aim of this study was to assess the feasibility of designing and introducing generic 3D-printed instrumentation for routine use in total knee arthroplasty. Instruments were designed to take advantage of 3D-printing technology, particularly ensuring that all parts were pre-assembled, to theoretically reduce the time and skill required during surgery. Concerning functionality, ranges of resection angle and distance were restricted within a safe zone, while accommodating either mechanical or anatomical alignment goals. To identify the most suitable biocompatible materials, typical instrument shapes and mating parts, such as dovetails and screws, were designed and produced.Aims
Materials and Methods
This article presents a unified clinical theory
that links established facts about the physiology of bone and homeostasis,
with those involved in the healing of fractures and the development
of nonunion. The key to this theory is the concept that the tissue
that forms in and around a fracture should be considered a specific
functional entity. This ‘bone-healing unit’ produces a physiological
response to its biological and mechanical environment, which leads
to the normal healing of bone. This tissue responds to mechanical
forces and functions according to Wolff’s law, Perren’s strain theory
and Frost’s concept of the “mechanostat”. In response to the local
mechanical environment, the bone-healing unit normally changes with
time, producing different tissues that can tolerate various levels
of strain. The normal result is the formation of bone that bridges
the fracture – healing by callus. Nonunion occurs when the bone-healing
unit fails either due to mechanical or biological problems or a
combination of both. In clinical practice, the majority of nonunions
are due to mechanical problems with instability, resulting in too
much strain at the fracture site. In most nonunions, there is an
intact bone-healing unit. We suggest that this maintains its biological
potential to heal, but fails to function due to the mechanical conditions.
The theory predicts the healing pattern of multifragmentary fractures
and the observed morphological characteristics of different nonunions.
It suggests that the majority of nonunions will heal if the correct
mechanical environment is produced by surgery, without the need
for biological adjuncts such as autologous bone graft. Cite this article:
Nail patella syndrome (NPS) is a skeletal dysplasia with patellofemoral
dysfunction as a key symptom. We present the first in-depth radiological
evaluation of the knee in a large series of NPS patients and describe
the typical malformations. Conventional radiological examination of 95 skeletally mature
patients with NPS was performed. Patellar morphology was classified
according to the Wiberg classification as modified by Baumgartl
and Ficat criteria, and trochlear shape was classified according
to the Dejour classification.Aim
Patients and Methods
Deformity of the proximal femur in fibrous dysplasia
leads to deviation of the mechanical axis of the hip, which may lead
to the development of secondary osteoarthritis (OA). This study
investigated the prevalence and predisposing factors for the development
of OA in patients with fibrous dysplasia of the proximal femur.
We reviewed the records of 209 patients from our institutional database
with fibrous dysplasia of the proximal femur, investigating possible predisposing
factors including patient demographics, the extent of the coxa vara
deformity, the presence of peri-articular disease, and the overall
burden of skeletal disease. Of the 209 patients, 24 (12%) had radiological
evidence of OA in the ipsilateral hip. The prevalence was significantly
higher in patients with polyostotic fibrous dysplasia compared with
those with monostotic disease (p <
0.001). In a subgroup analysis of
patients with polyostotic disease, the extent of deformity (quantified
using the neck–shaft angle), and the presence of peri-articular
disease (whether in the head of the femur or the acetabulum) were
significant predictors of osteoarthritis (neck–shaft angle likelihood
ratio (LR) = 0.847 per 1° increase, p = 0.004; presence of lesion
in the head of the femur LR = 9.947, p = 0.027; presence of lesion
in the acetabulum LR = 11.231, p = 0.014). Our data suggest that patients with polyostotic fibrous dysplasia
have a high risk of developing secondary OA of the hips. This risk
is higher in patients with peri-articular disease, and those with
a more severe deformity of proximal femur. Cite this article:
Monostotic fibrous dysplasia of the proximal
femur has a variable clinical course, despite its reported limited tendency
to progress. We investigated the natural history and predisposing factors
for progression of dysplasia in a group of 76 patients with a mean
follow-up of 8.5 years (2.0 to 15.2). Of these, 31 (41%) presented
with an asymptomatic incidental lesion while 45 (59%) presented
with pain or a pathological fracture. A group of 23 patients (30%)
underwent early operative treatment for pain (19: 25%) or pathological
fracture (4: 5%). Of the 53 patients who were initially treated non-operatively,
45 (85%) remained asymptomatic but eight (15%) needed surgery because
of pain or fracture. The progression-free survival of the observation
group was 81% ( The risk of experiencing pain or pathological fracture is considerable
in monostotic fibrous dysplasia of the proximal femur. Patients
presenting with pain, a limp or radiological evidence of microfracture
have a high chance of needing surgical treatment. Cite this article:
We investigated the relationship between spinopelvic
parameters and disc degeneration in young adult patients with spondylolytic
spondylolisthesis. A total of 229 men with a mean age of 21 years
(18 to 26) with spondylolytic spondylolisthesis were identified.
All radiological measurements, including pelvic incidence, sacral
slope, pelvic tilt, lumbar lordosis, sacral inclination, lumbosacral
angle (LSA), and sacrofemoral distance, were calculated from standing
lateral lumbosacral radiographs. The degree of intervertebral disc
degeneration was classified using a modified Pfirrmann scale. We
analysed the spinopelvic parameters according to disc level, degree
of slip and disc degeneration. There were significant positive correlations between the degree
of slip and pelvic incidence (p = 0.009), sacral slope (p = 0.003)
and lumbar lordosis (p = 0.010). The degree of slip and the LSA
were correlated with disc degeneration (p <
0.001 and p = 0.003,
respectively). There was also a significant difference between the
degree of slip (p <
0.001) and LSA (p = 0.006) according to the
segmental level of disc degeneration. Cite this article:
We used demineralised bone matrix (DBM) to augment re-attachment of tendon to a metal prosthesis in an A significant increase of 23.5% was observed in functional weight-bearing at six weeks in the DBM-augmented group compared with non-augmented controls (p = 0.004). By 12 weeks augmentation with DBM resulted in regeneration of a more direct-type enthesis, with regions of fibrocartilage, mineralised fibrocartilage and bone. In the controls the interface was predominantly indirect, with the tendon attached to the bone graft-hydroxyapatite base plate by perforating collagen fibres.
We analysed whether a high body mass index (BMI)
had a deleterious effect on outcome following autologous chondrocyte
implantation (ACI) or matrix-carried autologous chondrocyte implantation
(MACI) for the treatment of full-thickness chondral defects of the
knee from a subset of patients enrolled in the ACI vs MACI trial
at The Royal National Orthopaedic Hospital. The mean Modified Cincinnati scores (MCS) were significantly
higher (p <
0.001) post-operatively in patients who had an ideal
body weight (n = 53; 20 to 24.9 kg/m2) than in overweight
(n = 63; 25 to 30 kg/m2) and obese patients (n = 22;
>
30 kg/m2). At a follow-up of two years, obese patients
demonstrated no sustained improvement in the MCS. Patients with
an ideal weight experienced significant improvements as early as
six months after surgery (p = 0.007). In total, 82% of patients
(31 of 38) in the ideal group had a good or excellent result, compared
with 49% (22 of 45) of the overweight and 5.5% (one of 18) in the
obese group (p <
0.001). There was a significant negative relationship between
BMI and the MCS 24 months after surgery (r = -0.4, p = 0.001). This study demonstrates that obese patients have worse knee function
before surgery and experience no sustained benefit from ACI or MACI
at two years after surgery. There was a correlation between increasing
BMI and a lower MCS according to a linear regression analysis. On
the basis of our findings patient selection can be more appropriately
targeted.
In distal fibular resection without reconstruction,
the stabilising effect of the lateral malleolus is lost. Thus, the ankle
may collapse into valgus and may be unstable in varus. Here, we
describe a child who underwent successful staged surgical correction
of a severe neglected valgus deformity after excision of the distal
fibula for a Ewing’s sarcoma.