We investigated the long-term performance of the Tripolar Trident acetabular component used for recurrent dislocation in revision total hip arthroplasty. We assessed: 1) rate of re-dislocation; 2) incidence of complications requiring re-operation; and 3) Western Ontario and McMaster Universities osteoarthritis index (WOMAC) pain and functional scores. We retrospectively identified 111 patients who had 113 revision tripolar constrained liners between 1994 and 2008. All patients had undergone revision hip arthroplasty before the constrained liner was used: 13 after the first revision, 17 after the second, 38 after the third, and 45 after more than three revisions. A total of 75 hips (73 patients) were treated with Tripolar liners due to recurrent instability with abductor deficiency, In addition, six patients had associated cerebral palsy, four had poliomyelitis, two had multiple sclerosis, two had spina bifida, two had spondyloepiphyseal dysplasia, one had previous reversal of an arthrodesis, and 21 had proximal femoral replacements. The mean age of patients at time of Tripolar insertions was 72 years (53 to 89); there were 69 female patients (two bilateral) and 42 male patients. All patients were followed up for a mean of 15 years (10 to 24). Overall, 55 patients (57 hips) died between April 2011 and February 2018, at a mean of 167 months (122 to 217) following their tripolar liner implantation. We extracted demographics, implant data, rate of dislocations, and incidence of other complications.Aims
Patients and Methods
The primary aim of this study was to evaluate the performance
and safety of magnetically controlled growth rods in the treatment
of early onset scoliosis. Secondary aims were to evaluate the clinical
outcome, the rate of further surgery, the rate of complications,
and the durability of correction. We undertook an observational prospective cohort study of children
with early onset scoliosis, who were recruited over a one-year period
and followed up for a minimum of two years. Magnetically controlled
rods were introduced in a standardized manner with distractions
performed three-monthly thereafter. Adverse events which were both related
and unrelated to the device were recorded. Ten children, for whom
relevant key data points (such as demographic information, growth
parameters, Cobb angles, and functional outcomes) were available,
were recruited and followed up over the period of the study. There
were five boys and five girls. Their mean age was 6.2 years (2.5
to 10).Aims
Patients and Methods
It is important to consider sagittal pelvic rotation when introducing
the acetabular component at total hip arthroplasty (THA). The purpose
of this study was to identify patients who are at risk of unfavourable
pelvic mobility, which could result in poor outcomes after THA. A consecutive series of 4042 patients undergoing THA had lateral
functional radiographs and a low-dose CT scan to measure supine
pelvic tilt, pelvic incidence, standing pelvic tilt, flexed-seated
pelvic tilt, standing lumbar lordotic angle, flexed-seated lumbar
lordotic angle, and lumbar flexion. Changes in pelvic tilt from
supine-to-standing positions and supine-to-flexed-seated positions
were determined. A change in pelvic tilt of 13° between positions was
deemed unfavourable as it alters functional anteversion by 10° and
effectively places the acetabular component outside the safe zone
of orientation.Aims
Patients and Methods
The hip’s capsular ligaments passively restrain extreme range of movement (ROM) by wrapping around the native femoral head/neck. We determined the effect of hip resurfacing arthroplasty (HRA), dual-mobility total hip arthroplasty (DM-THA), conventional THA, and surgical approach on ligament function. Eight paired cadaveric hip joints were skeletonized but retained the hip capsule. Capsular ROM restraint during controlled internal rotation (IR) and external rotation (ER) was measured before and after HRA, DM-THA, and conventional THA, with a posterior (right hips) and anterior capsulotomy (left hips).Aims
Materials and Methods
The aim of this study was to identify predictors of return to
work (RTW) after revision lower limb arthroplasty in patients of
working age in the United Kingdom. We assessed 55 patients aged ≤ 65 years after revision total
hip arthroplasty (THA). There were 43 women and 12 men with a mean
age of 54 years (23 to 65). We also reviewed 30 patients after revision
total knee arthroplasty (TKA). There were 14 women and 16 men with
a mean age of 58 years (48 to 64). Preoperatively, age, gender,
body mass index, social deprivation, mode of failure, length of
primary implant survival, work status and nature, activity level
(University of California, Los Angeles (UCLA) score), and Oxford
Hip and Knee Scores were recorded. Postoperatively, RTW status,
Oxford Hip and Knee Scores, EuroQol-5D (EQ-5D), UCLA score, and
Work, Osteoarthritis and Joint-Replacement Questionnaire (WORQ)
scores were obtained. Univariate and multivariate analysis was performed.Aims
Patients and Methods
Instability continues to be a troublesome complication after total hip arthroplasty (THA). Patient-related risk factors associated with a higher dislocation risk include the preoperative diagnosis, an age of 75 years or older, high body mass index (BMI), a history of alcohol abuse, and neurodegenerative diseases. The goal of this study was to assess the dislocation rate, radiographic outcomes, and complications of patients stratified as high-risk for dislocation who received a dual mobility (DM) bearing in a primary THA at a minimum follow-up of two years. We performed a retrospective review of a consecutive series of DM THA performed between 2010 and 2014 at our institution (Hospital for Special Surgery, New York, New York) by a single, high-volume orthopaedic surgeon employing a single prosthesis design (Anatomic Dual Mobility (ADM) Stryker, Mahwah, New Jersey). Patient medical records and radiographs were reviewed to confirm the type of implant used, to identify any preoperative risk factors for dislocation, and any complications. Radiographic analysis was performed to assess for signs of osteolysis or remodelling of the acetabulum.Aims
Materials 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
Aims
Patients and Methods
The aim of this study was to investigate the impact of maturity status at the time of surgery on final spinal height in patients with an adolescent idiopathic scoliosis (AIS) using the spine-pelvic index (SPI). The SPI is a self-control ratio that is independent of age and maturity status. The study recruited 152 female patients with a Lenke 1 AIS. The additional inclusion criteria were a thoracic Cobb angle between 45° and 70°, Risser 0 to 1 or 3 to 4 at the time of surgery, and follow-up until 18 years of age or Risser stage 5. The patients were stratified into four groups: Risser 0 to 1 and selective fusion surgery (Group 1), Risser 0 to 1 and non-selective fusion (Group 2), Risser 3 to 4 and selective fusion surgery (Group 3), and Risser 3 to 4 and non-selective fusion (Group 4). The height of spine at follow-up (HOSf) and height of pelvis at follow-up (HOPf) were measured and the predicted HOS (pHOS) was calculated as 2.22 (SPI) × HOPf. One-way analysis of variance (ANOVA) was performed for statistical analysis.Aims
Patients and Methods
This study reports the mid-term results of total hip arthroplasty (THA) performed using a monoblock acetabular component with a large-diameter head (LDH) ceramic-on-ceramic (CoC) bearing. Of the 276 hips (246 patients) included in this study, 264 (96%) were reviewed at a mean of 67 months (48 to 79) postoperatively. Procedures were performed with a mini posterior approach. Clinical and radiological outcomes were recorded at regular intervals. A noise assessment questionnaire was completed at last follow-up.Aims
Patients and Methods
The aim of this study was to systematically review the literature on measurement of muscle strength in patients with femoroacetabular impingement (FAI) and other pathologies and to suggest guidelines to standardise protocols for future research in the field. The Cochrane and PubMed libraries were searched for any publications using the terms ‘hip’, ‘muscle’, ‘strength’, and ‘measurement’ in the ‘Title, Abstract, Keywords’ field. A further search was performed using the terms ‘femoroacetabular’ or ‘impingement’. The search was limited to recent literature only.Objectives
Methods
Magnetically controlled growing rods (MCGRs) allow non-invasive
correction of the spinal deformity in the treatment of early-onset
scoliosis. Conventional growing rod systems (CGRS) need repeated
surgical distractions: these are associated with the effect of the
‘law of diminishing returns’. The primary aim of this study was to quantify this effect in
MCGRs over sequential distractions. A total of 35 patients with a maximum follow-up of 57 months
were included in the study. There were 17 boys and 18 girls with
a mean age of 7.4 years (2 to 14). True Distraction (TD) was determined
by measuring the expansion gap on fluoroscopy. This was compared
with Intended Distraction (ID) and expressed as the ‘T/I’ ratio.
The T/I ratio and the Cobb angle were calculated at several time
points during follow-up.Aims
Patients and Methods
Open reduction is required following failed conservative treatment
of developmental dysplasia of the hip (DDH). The Ludloff medial
approach is commonly used, but poor results have been reported,
with rates of the development of avascular necrosis (AVN) varying
between 8% and 54%. This retrospective cohort study evaluates the
long-term radiographic and clinical outcome of dislocated hips treated
using this approach. Children with a dislocated hip, younger than one year of age
at the time of surgery, who were treated using a medial approach
were eligible for the study. Radiographs were evaluated for the
degree of dislocation and the presence of an ossific nucleus preoperatively,
and for the degree of AVN and residual dysplasia at one and five
years and at a mean of 12.7 years (4.6 to 20.8) postoperatively.
Radiographic outcome was assessed using the Severin classification,
after five years of age. Further surgical procedures were recorded.
Functional outcome was assessed using the Pediatric Outcomes Data
Collection Instrument (PODCI) or the Hip Disability and Osteoarthritis
Outcome Score (HOOS), depending on the patient’s age.Aims
Patients and Methods
