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
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:
The aim of this study was to evaluate fretting and corrosion in retrieved oxidized zirconium (OxZr; OXINIUM, Smith & Nephew, Memphis, Tennessee) femoral heads and compare the results with those from a matched cohort of cobalt-chromium (CoCr) femoral heads. A total of 28 OxZr femoral heads were retrieved during revision total hip arthroplasty (THA) and matched to 28 retrieved CoCr heads according to patient demographics. The mean age at index was 56 years (46 to 83) in the OxZr group and 70 years (46 to 92) in the CoCr group. Fretting and corrosion scores of the female taper of the heads were measured according to the modified Goldberg scoring method.Aims
Patients and Methods
The medially spherical GMK Sphere (Medacta International AG, Castel San Pietro, Switzerland) total knee arthroplasty (TKA) was previously shown to accommodate lateral rollback while pivoting around a stable medial compartment, aiming to replicate native knee kinematics in which some coronal laxity, especially laterally, is also present. We assess coronal plane kinematics of the GMK Sphere and explore the occurrence and pattern of articular separation during static and dynamic activities. Using pulsed fluoroscopy and image matching, the coronal kinematics and articular surface separation of 16 well-functioning TKAs were studied during weight-bearing and non-weight-bearing, static, and dynamic activities. The closest distances between the modelled articular surfaces were examined with respect to knee position, and proportions of joint poses exhibiting separation were computed.Objectives
Methods
Cardiac magnetic resonance (CMR) was used to assess whether cardiac function or tissue composition was affected in patients with well-functioning metal-on-metal hip resurfacing arthroplasties (MoMHRA) when compared with a group of controls, and to assess if metal ion levels correlated with any of the functional or structural parameters studied. In all, 30 participants with no significant cardiac history were enrolled: 20 patients with well-functioning MoMHRA at mean follow-up of 8.3 years post-procedure (ten unilateral, ten bilateral; 17 men, three women) and a case-matched control group of ten non-MoM total hip arthroplasty patients (six men, four women). The mean age of the whole cohort (study group and controls) at the time of surgery was 50.6 years (41.0 to 64.0). Serum levels of cobalt and chromium were measured, and all patients underwent CMR imaging, including cine, T2* measurements, T1 and T2 mapping, late gadolinium enhancement, and strain measurements.Aims
Patients and Methods
The purpose of this study was to compare two different types
of metal-on-metal (MoM) bearing for total hip arthroplasty (THA):
one with a large femoral head (38 mm to 52 mm) and the other with
a conventional femoral head (28 mm or 32 mm). We compared clinical
outcome, blood metal ion levels, and the incidence of pseudotumour in
the two groups. Between December 2009 and December 2011, 62 patients underwent
MoM THA with a large femoral head (Magnum group) and 57 patients
an MoM THA with a conventional femoral head (conventional group).
Clinical outcome was assessed using the Harris Hip score, University
of California, Los Angeles (UCLA) activity score and EuroQol-5D
(EQ-5D). Blood metal ion levels were measured and MRI scans were
analyzed at a minimum of five years postoperatively.Aims
Patients and Methods
The aim of this study was to evaluate two hypotheses. First,
that disruption of posterior bundle of the medial collateral ligament
(PMCL) has to occur for the elbow to subluxate in cases of posteromedial
rotatory instability (PMRI) and second, that ulnohumeral contact
pressures increase after disruption of the PMCL. Six human cadaveric elbows were prepared on a custom-designed
apparatus which allowed muscle loading and passive elbow motion
under gravitational varus. Joint contact pressures were measured
sequentially in the intact elbow (INTACT), followed by an anteromedial
subtype two coronoid fracture (COR), a lateral collateral ligament (LCL)
tear (COR + LCL), and a PMCL tear (COR + LCL + PMCL).Aims
Materials and Methods
The aim of this study was to report the mid-term clinical outcome
of cemented unlinked J-alumina ceramic elbow (JACE) arthroplasties
when used in patients with rheumatoid arthritis (RA). We retrospectively reviewed 87 elbows, in 75 patients with RA,
which was replaced using a cemented JACE total elbow arthroplasty
(TEA) between August 2003 and December 2012, with a follow-up of
96%. There were 72 women and three men, with a mean age of 62 years
(35 to 79). The mean follow-up was nine years (2 to 14). The clinical condition
of each elbow before and after surgery was assessed using the Mayo
Elbow Performance Index (MEPI, 0 to 100 points). Radiographic loosening
was defined as a progressive radiolucent line of >1 mm that was
completely circumferential around the prosthesis.Aims
Patients and Methods
Unicompartmental knee arthroplasty (UKA) is an alternative to total knee arthroplasty for patients who require treatment of single-compartment osteoarthritis, especially for young patients. To satisfy this requirement, new patient-specific prosthetic designs have been introduced. The patient-specific UKA is designed on the basis of data from preoperative medical images. In general, knee implant design with increased conformity has been developed to provide lower contact stress and reduced wear on the tibial insert compared with flat knee designs. The different tibiofemoral conformity may provide designers the opportunity to address both wear and kinematic design goals simultaneously. The aim of this study was to evaluate wear prediction with respect to tibiofemoral conformity design in patient-specific UKA under gait loading conditions by using a previously validated computational wear method. Three designs with different conformities were developed with the same femoral component: a flat design normally used in fixed-bearing UKA, a tibia plateau anatomy mimetic (AM) design, and an increased conforming design. We investigated the kinematics, contact stress, contact area, wear rate, and volumetric wear of the three different tibial insert designs.Objectives
Methods
The treatment of patients with allergies to metal in total joint arthroplasty is an ongoing debate. Possibilities include the use of hypoallergenic prostheses, as well as the use of standard cobalt-chromium (CoCr) alloy. This non-designer study was performed to evaluate the clinical outcome and survival rates of unicondylar knee arthroplasty (UKA) using a standard CoCr alloy in patients reporting signs of a hypersensitivity to metal. A consecutive series of patients suitable for UKA were screened for symptoms of metal hypersensitivity by use of a questionnaire. A total of 82 patients out of 1737 patients suitable for medial UKA reporting cutaneous metal hypersensitivity to cobalt, chromium, or nickel were included into this study and prospectively evaluated to determine the functional outcome, possible signs of hypersensitivity, and short-term survivorship at a minimum follow-up of 1.5 years.Aims
Patients and Methods
Bone void fillers are increasingly being used for dead space management in arthroplasty revision surgery. The aim of this study was to investigate the influence of calcium sulphate bone void filler (CS-BVF) on the damage and wear of total knee arthroplasty using experimental wear simulation. A total of 18 fixed-bearing U2 total knee arthroplasty system implants (United Orthopedic Corp., Hsinchu, Taiwan) were used. Implants challenged with CS-BVF were compared with new implants (negative controls) and those intentionally scratched with a diamond stylus (positive controls) representative of severe surface damage (n = 6 for each experimental group). Three million cycles (MC) of experimental simulation were carried out to simulate a walking gait cycle. Wear of the ultra-high-molecular-weight polyethylene (UHMWPE) tibial inserts was measured gravimetrically, and damage to articulating surfaces was assessed using profilometry.Objectives
Methods
Surface replacement arthroplasty (SRA), compared with traditional total hip arthroplasty (THA), is more expensive and carries unique concern related to metal ions production and hypersensitivity. Additionally, SRA is a more demanding procedure with a decreased margin for error compared with THA. To justify its use, SRA must demonstrate comparable component survival and some clinical advantages. We therefore performed a systematic literature review to investigate the differences in complication rates, patient-reported outcomes, stress shielding, and hip biomechanics between SRA and THA. A systematic review of the literature was completed using MEDLINE and EMBASE search engines. Inclusion criteria were level I to level III articles that reported clinical outcomes following primary SRA compared with THA. An initial search yielded 2503 potential articles for inclusion. Exclusion criteria included review articles, level IV or level V evidence, less than one year’s follow-up, and previously reported data. In total, 27 articles with 4182 patients were available to analyze.Aims
Materials and Methods
We conducted a prospective study of a delta ceramic total hip
arthroplasty (THA) to determine the rate of ceramic fracture, to
characterise post-operative noise, and to evaluate the mid-term
results and survivorship. Between March 2009 and March 2011, 274 patients (310 hips) underwent
cementless THA using a delta ceramic femoral head and liner. At
each follow-up, clinical and radiological outcomes were recorded.
A Kaplan-Meier analysis was undertaken to estimate survival.Aims
Patients and Methods
Aims
Materials and Methods
Aims
Patients and Methods
Aims
Patients and Methods
The pathogenesis of intraneural ganglion cysts is controversial.
Recent reports in the literature described medial plantar intraneural
ganglion cysts (mIGC) with articular branches to subtalar joints.
The aim of the current study was to provide further support for
the principles underlying the articular theory, and to explain the
successes and failures of treatment of mICGs. Between 2006 and 2017, five patients with five mICGs were retrospectively
reviewed. There were five men with a mean age of 50.2 years (33
to 68) and a mean follow-up of 3.8 years (0.8 to 6). Case history,
physical examination, imaging, and intraoperative findings were
reviewed. The outcomes of interest were ultrasound and/or MRI features
of mICG, as well as the clinical outcomes.Aims
Patients and Methods
