Asphericity of the femoral head-neck junction is common in cam-type
femoroacetabular impingement (FAI) and usually quantified using
the alpha angle on radiographs or MRI. The aim of this study was
to determine the natural alpha angle in a large cohort of patients
by continuous circumferential analysis with CT. CT scans of 1312 femurs of 656 patients were analyzed in this
cross-sectional study. There were 362 men and 294 women. Their mean
age was 61.2 years (18 to 93). All scans had been performed for
reasons other than hip disease. Digital circumferential analysis
allowed continuous determination of the alpha angle around the entire
head-neck junction. All statistical tests were conducted two-sided;
a p-value < 0.05 was considered statistically significant.Aims
Methods
The aim of this study was to compare the cost-effectiveness of
treatment with an osseointegrated percutaneous (OI-) prosthesis
and a socket-suspended (S-) prosthesis for patients with a transfemoral
amputation. A Markov model was developed to estimate the medical costs and
changes in quality-adjusted life-years (QALYs) attributable to treatment
of unilateral transfemoral amputation over a projected period of
20 years from a healthcare perspective. Data were collected alongside
a prospective clinical study of 51 patients followed for two years.Aims
Patients and Methods
Anatomical total knee arthroplasty alignment
The aim of this study was to assess the current evidence relating
to the benefits of virtual reality (VR) simulation in orthopaedic
surgical training, and to identify areas of future research. A literature search using the MEDLINE, Embase, and Google Scholar
databases was performed. The results’ titles, abstracts, and references
were examined for relevance.Aims
Materials and Methods
An important measure for the diagnosis and monitoring of knee osteoarthritis is the minimum joint space width (mJSW). This requires accurate alignment of the x-ray beam with the tibial plateau, which may not be accomplished in practice. We investigate the feasibility of a new mJSW measurement method from stereo radiographs using 3D statistical shape models (SSM) and evaluate its sensitivity to changes in the mJSW and its robustness to variations in patient positioning and bone geometry. A validation study was performed using five cadaver specimens. The actual mJSW was varied and images were acquired with variation in the cadaver positioning. For comparison purposes, the mJSW was also assessed from plain radiographs. To study the influence of SSM model accuracy, the 3D mJSW measurement was repeated with models from the actual bones, obtained from CT scans.Objectives
Materials and Methods
The purpose of this study was to evaluate the existing literature from 2005 to 2016 reporting on the efficacy of surgical management of patients with femoroacetabular impingement (FAI) secondary to slipped capital femoral epiphysis (SCFE). The electronic databases MEDLINE, EMBASE, and PubMed were searched and screened in duplicate. Data such as patient demographics, surgical technique, surgical outcomes and complications were retrieved from eligible studies.Objectives
Methods
Posterior tilt of the pelvis with sitting provides biological
acetabular opening. Our goal was to study the post-operative interaction
of skeletal mobility and sagittal acetabular component position. This was a radiographic study of 160 hips (151 patients) who
prospectively had lateral spinopelvic hip radiographs for skeletal
and implant measurements. Intra-operative acetabular component position
was determined according to the pre-operative spinal mobility. Sagittal
implant measurements of ante-inclination and sacral acetabular angle were
used as surrogate measurements for the risk of impingement, and
intra-operative acetabular component angles were compared with these.Aims
Materials and Methods
The primary aim of this study was to analyse the position of
the acetabular and femoral components in total hip arthroplasty
undertaken using an anterior surgical approach. In a prospective, single centre study, we used the EOS imaging
system to analyse the position of components following THA performed
via the anterior approach in 102 patients (103 hips) with a mean
age of 64.7 years (Aims
Patients and Methods
Tibiofemoral alignment is important to determine the rate of
progression of osteoarthritis and implant survival after total knee
arthroplasty (TKA). Normally, surgeons aim for neutral tibiofemoral
alignment following TKA, but this has been questioned in recent
years. The aim of this study was to evaluate whether varus or valgus
alignment indeed leads to increased medial or lateral tibiofemoral
forces during static and dynamic weight-bearing activities. Tibiofemoral contact forces and moments were measured in nine
patients with instrumented knee implants. Medial force ratios were
analysed during nine daily activities, including activities with
single-limb support (e.g. walking) and double-limb support (e.g.
knee bend). Hip-knee-ankle angles in the frontal plane were analysed
using full-leg coronal radiographs. Aims
Patients and Methods
Modular junctions are ubiquitous in contemporary hip arthroplasty. The head-trunnion junction is implicated in the failure of large diameter metal-on-metal (MoM) hips which are the currently the topic of one the largest legal actions in the history of orthopaedics (estimated costs are stated to exceed $4 billion). Several factors are known to influence the strength of these press-fit modular connections. However, the influence of different head sizes has not previously been investigated. The aim of the study was to establish whether the choice of head size influences the initial strength of the trunnion-head connection. Ti-6Al-4V trunnions (n = 60) and two different sizes of cobalt-chromium (Co-Cr) heads (28 mm and 36 mm; 30 of each size) were used in the study. Three different levels of assembly force were considered: 4 kN; 5 kN; and 6 kN (n = 10 each). The strength of the press-fit connection was subsequently evaluated by measuring the pull-off force required to break the connection. The statistical differences in pull-off force were examined using a Kruskal–Wallis test and two-sample Mann–Whitney U test. Finite element and analytical models were developed to understand the reasons for the experimentally observed differences.Objectives
Materials and Methods
Patient-specific glenoid guides (PSGs) claim an improvement in
accuracy and reproducibility of the positioning of components in
total shoulder arthroplasty (TSA). The results have not yet been
confirmed in a prospective clinical trial. Our aim was to assess
whether the use of PSGs in patients with osteoarthritis of the shoulder
would allow accurate and reliable implantation of the glenoid component. A total of 17 patients (three men and 14 women) with a mean age
of 71 years (53 to 81) awaiting TSA were enrolled in the study.
Pre- and post-operative version and inclination of the glenoid were
measured on CT scans, using 3D planning automatic software. During
surgery, a congruent 3D-printed PSG was applied onto the glenoid
surface, thus determining the entry point and orientation of the
central guide wire used for reaming the glenoid and the introduction
of the component. Manual segmentation was performed on post-operative
CT scans to compare the planned and the actual position of the entry
point (mm) and orientation of the component (°).Aims
Patients and Methods
Patients with neuromuscular imbalance who require
total hip arthroplasty (THA) present particular technical problems
due to altered anatomy, abnormal bone stock, muscular imbalance
and problems of rehabilitation. In this systematic review, we studied articles dealing with THA
in patients with neuromuscular imbalance, published before April
2017. We recorded the demographics of the patients and the type
of neuromuscular pathology, the indication for surgery, surgical
approach, concomitant soft-tissue releases, the type of implant
and bearing, pain and functional outcome as well as complications
and survival. Recent advances in THA technology allow for successful outcomes
in these patients. Our review suggests excellent benefits for pain
relief and good functional outcome might be expected with a modest
risk of complication. Cite this article:
Adverse reaction to wear and corrosion debris
is a cause for concern in total hip arthroplasty (THA). Modular junctions
are a potential source of such wear products and are associated
with secondary pseudotumour formation. We present a consecutive series of 17 patients treated at our
unit for this complication following metal-on-highly cross-linked
polyethylene (MoP) THA. We emphasise the risk of misdiagnosis as
infection, and present the aggregate laboratory results and pathological
findings in this series. The clinical presentation was pain, swelling or instability.
Solid, cystic and mixed soft-tissue lesions were noted on imaging
and confirmed intra-operatively. Corrosion at the head–neck junction
was noted in all cases. No bacteria were isolated on multiple pre-
and intra-operative samples yet the mean erythrocyte sedimentation
rate was 49 (9 to 100) and C-reactive protein 32 (0.6 to 106) and
stromal polymorphonuclear cell counts were noted in nine cases. Adverse soft–tissue reactions can occur in MoP THA owing to corrosion
products released from the head–neck junction. The diagnosis should
be carefully considered when investigating pain after THA. This
may avoid the misdiagnosis of periprosthetic infection with an unidentified
organism and mitigate the unnecessary management of these cases
with complete single- or two-stage exchange. Cite this article:
The objective of this five-year prospective, blinded, randomised
controlled trial (RCT) was to compare femoral head penetration into
a vitamin E diffused highly cross-linked polyethylene (HXLPE) liner
with penetration into a medium cross-linked polyethylene control
liner using radiostereometric analysis. Patients scheduled for total hip arthroplasty (THA) were randomised
to receive either the study E1 (32 patients) or the control ArComXL
polyethylene (35 patients). The median age (range) of the overall
cohort was 66 years (40 to 76).Aims
Patients and Methods
In order to prevent dislocation of the hip after total hip arthroplasty
(THA), patients have to adhere to precautions in the early post-operative
period. The hypothesis of this study was that a protocol with minimal
precautions after primary THA using the posterolateral approach
would not increase the short-term (less than three months) risk
of dislocation. We prospectively monitored a group of unselected patients undergoing
primary THA managed with standard precautions (n = 109, median age
68.9 years; interquartile range (IQR) 61.2 to 77.3) and a group
who were managed with fewer precautions (n = 108, median age 67.2
years; IQR 59.8 to 73.2). There were no significant differences between
the groups in relation to predisposing risk factors. The diameter
of the femoral head ranged from 28 mm to 36 mm; meticulous soft-tissue
repair was undertaken in all patients. The medical records were
reviewed and all patients were contacted three months post-operatively
to confirm whether they had experienced a dislocation. Aims
Patients and Methods
We present a minimum 20-year follow-up study of 382 cemented
Exeter Universal total hip arthroplasties (350 patients) operated
on at a mean age of 66.3 years (17 to 94). All patients received the same design of femoral component, regardless
of the original diagnosis. Previous surgery had been undertaken
for 33 hips (8.6%). During the study period 218 patients with 236
hips (62%) died, 42 hips (11%) were revised and 110 hips (29%) in
96 patients were available for review. The acetabular components
were varied and some designs are now obsolete, however they were
all cemented.Aims
Patients and Methods
