Dual mobility (DM) bearings are an attractive treatment option to obtain hip stability during challenging primary and revision total hip arthroplasty (THA) cases. The purpose of this study was to analyze data submitted to the American Joint Replacement Registry (AJRR) to characterize utilization trends of DM bearings in the USA. All primary and revision THA procedures reported to AJRR from 2012 to 2018 were analyzed. Patients of all ages were included and subdivided into DM and traditional bearing surface cohorts. Patient demographics, geographical region, hospital size, and teaching affiliation were assessed. Associations were determined by chi-squared analysis and logistic regression was performed to assess outcome variables.Aims
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
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
While previously underappreciated, factors related to the spine contribute substantially to the risk of dislocation following total hip arthroplasty (THA). These factors must be taken into consideration during preoperative planning for revision THA due to recurrent instability. We developed a protocol to assess the functional position of the spine, the significance of these findings, and how to address different pathologies at the time of revision THA. Prospectively collected data on 111 patients undergoing revision THA for recurrent instability from January 2014 to January 2017 at two institutions were included (protocol group) and matched 1:1 to 111 revisions specifically performed for instability not using this protocol (control group). Mean follow-up was 2.8 years. Protocol patients underwent standardized preoperative imaging including supine and standing anteroposterior (AP) pelvis and lateral radiographs. Each case was scored according to the Hip-Spine Classification in Revision THA.Aims
Patients and Methods
There remains confusion in the literature with regard to the spinopelvic relationship, and its contribution to ideal acetabular component position. Critical assessment of the literature has been limited by use of conflicting terminology and definitions of new concepts that further confuse the topic. In 2017, the concept of a Hip-Spine Workgroup was created with the first meeting held at the American Academy of Orthopedic Surgeons Annual Meeting in 2018. The goal of this workgroup was to first help standardize terminology across the literature so that as a topic, multiple groups could produce literature that is immediately understandable and applicable. This consensus review from the Hip-Spine Workgroup aims to simplify the spinopelvic relationship, offer hip surgeons a concise summary of available literature, and select common terminology approved by both hip surgeons and spine surgeons for future research. Cite this article:
Instability remains a challenging problem in both primary and
revision total hip arthroplasty (THA). Dual mobility components
confer increased stability, but there are concerns about the unique
complications associated with these designs, as well as the long-term
survivorship. We performed a systematic review of all English language articles
dealing with dual mobility THAs published between 2007 and 2016
in the MEDLINE and Embase electronic databases. A total of 54 articles
met inclusion criteria for the final analysis of primary and revision
dual mobility THAs and dual mobility THAs used in the treatment
of fractures of the femoral neck. We analysed the survivorship and
rates of aseptic loosening and of intraprosthetic and extra-articular
dislocation.Aims
Materials and Methods
Modular dual mobility (DM) prostheses in which a cobalt-chromium liner is inserted into a titanium acetabular shell ( This was a prospective study of patients between 18 and 65 years of age, with a body mass index (BMI) < 35 kg/m2 and University of California at Los Angeles (UCLA) activity score > 6, who received a modular cobalt-chromium acetabular liner, highly crosslinked polyethylene mobile bearing, and cementless titanium femoral stem for their primary THA. Patients with a history of renal disease and metal hardware elsewhere in the body were excluded. A total of 43 patients (30 male, 13 female; mean age 52.6 years (Aims
Patients and Methods
Our aim was to evaluate the radiographic characteristics of patients
undergoing total hip arthroplasty (THA) for the potential of posterior
bony impingement using CT simulations. Virtual CT data from 112 patients who underwent THA were analysed.
There were 40 men and 72 women. Their mean age was 59.1 years (41
to 76). Associations between radiographic characteristics and posterior
bony impingement and the range of external rotation of the hip were
evaluated. In addition, we investigated the effects of pelvic tilt
and the neck/shaft angle and femoral offset on posterior bony impingement.Aims
Patients and Methods
The aim of this systematic review was to report the rate of dislocation
following the use of dual mobility (DM) acetabular components in
primary and revision total hip arthroplasty (THA). A systematic review of the literature according to the Preferred
Reporting Items for Systematic Reviews and Meta-analyses guidelines
was performed. A comprehensive search of Pubmed/Medline, Cochrane
Library and Embase (Scopus) was conducted for English articles between
January 1974 and March 2016 using various combinations of the keywords “dual
mobility”, “dual-mobility”, “tripolar”, “double-mobility”, “double
mobility”, “hip”, “cup”, “socket”. The following data were extracted
by two investigators independently: demographics, whether the operation
was a primary or revision THA, length of follow-up, the design of
the components, diameter of the femoral head, and type of fixation
of the acetabular component.Aims
Materials and Methods
A possible solution for the management of proximal femoral bone
loss is a modular femoral endoprosthesis (EPR). Although the outcome
of EPRs in tumour surgery has been well described, the outcome of
their use in revision hip surgery has received less attention. The
aim of this study was to describe the outcome of using EPR for non-neoplastic
indications. A retrospective review of 79 patients who underwent 80 EPRs for
non-neoplastic indications was performed, including the rates of
complication and survival and the mean Oxford Hip Scores (OHS),
at a mean of five years post-operatively. The mean age at the time
of surgery was 69 years (28 to 93) and the mean number of previous operations
on the hip was 2.4 (0 to 17). The most common indications for EPR
implantation were periprosthetic joint infection (PJI) (n = 40),
periprosthetic fracture (n = 12) and failed osteosynthesis of a
proximal femoral fracture or complex trauma (n = 11).Objectives
Methods
Dual mobility cups have two points of articulation,
one between the shell and the polyethylene (external bearing) and
one between the polyethylene and the femoral head (internal bearing).
Movement occurs at the inner bearing; the outer bearing only moves
at extremes of movement. Dislocation after total hip arthroplasty (THA) is a cause of
much morbidity and its treatment has significant cost implications.
Dual mobility cups provide an increased range of movement and a
may reduce the risk of dislocation. This paper reviews the use of these cups in THA, particularly
where stability is an issue. Dual mobility cups may be of benefit
in primary THA in patients at a high risk of dislocation, such as
those who are older with increased comorbidities and a higher American
Association of Anesthesiology grade and those with a neuromuscular
disease. They may be used at revision surgery where the risk of
dislocation is high, such as in patients with many prior dislocations,
or those with abductor deficiency. They may also be used in THA
for displaced fractures of the femoral neck, which has a notoriously
high rate of dislocation. Cite this article:
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
Given the increasing number of total hip arthroplasty
procedures being performed annually, it is imperative that orthopaedic
surgeons understand factors responsible for instability. In order
to treat this potentially complex problem, we recommend correctly
classifying the type of instability present based on component position, abductor
function, impingement, and polyethylene wear. Correct classification
allows the treating surgeon to choose the appropriate revision option
that ultimately will allow for the best potential outcome. Cite this article:
Dislocation remains among the most common complications
of, and reasons for, revision of both primary and revision total
hip replacements (THR). Hence, there is great interest in maximising
stability to prevent this complication. Head size has been recognised
to have a strong influence on the risk of dislocation post-operatively.
As femoral head size increases, stability is augmented, secondary
to an increase in impingement-free range of movement. Larger head
sizes also greatly increase the ‘jump distance’ required for the
head to dislocate in an appropriately positioned cup. Level-one
studies support the use of larger diameter heads as they decrease
the risk of dislocation following primary and revision THR. Highly cross-linked
polyethylene has allowed us to increase femoral head size, without
a marked increase in wear. However, the thin polyethylene liners
necessary to accommodate larger heads may increase the risk of liner
fracture and larger heads have also been implicated in causing soft-tissue
impingement resulting in groin pain. Larger diameter heads also
impart larger forces on the femoral trunnion, which may contribute
to corrosion, metal release, and adverse local tissue reactions.
Alternative large bearings including large ceramic heads and dual
mobility bearings may mitigate some of these risks, and several
of these devices have been used with clinical success. Cite this article:
Surgical interventions consisting of internal
fixation (IF) or total hip replacement (THR) are required to restore
patient mobility after hip fractures. Conventionally, this decision
was based solely upon the degree of fracture displacement. However,
in the last ten years, there has been a move to incorporate patient
characteristics into the decision making process. Research demonstrating
that joint replacement renders superior functional results when compared
with IF, in the treatment of displaced femoral neck fractures, has
swayed the pendulum in favour of THR. However, a high risk of dislocation
has always been the concern. Fortunately, there are newer technologies
and alternative surgical approaches that can help reduce the risk
of dislocation. The authors propose an algorithm for the treatment
of femoral neck fractures: if minimally displaced, in the absence
of hip joint arthritis, IF should be performed; if arthritis is
present, or the fracture is displaced, then THR is preferred. Cite this article:
