Total hip replacement using an alumina head and socket and a titanium alloy stem is evaluated in a series of patients under 50 years of age. Between April 1977 and December 1986, 86 such replacements were performed in 75 patients, but mainly because patients had difficulty travelling from Africa, only 71 hips were followed up adequately; of these, 56 were primary procedures and 15 revisions. Survivorship analysis showed that 98% of the prostheses were retained for 10 years. On clinical and radiological examination 51 of the 71 hips were stable and acceptable, 15 had radiological changes on the acetabular side, and one on the femoral side; four other cases had clinical and radiological changes suggesting impending failure, possibly because fixation of the socket was inadequate. There were no differences between the results of the primary procedures and those of revisions. In these young patients, the results seem better with alumina-on-alumina hips than with other varieties, possibly because of their remarkably low
Bone loss around replacement prostheses may be related to the activation of mononuclear phagocytes (MNP) by prosthetic
The ability to determine human bone stiffness is of clinical relevance in many fields, including bone quality assessment and orthopaedic prosthesis design. Stiffness can be measured using compression testing, an experimental technique commonly used to test bone specimens A keyword search of all English language articles up until December 2017 of compression testing of bone was undertaken in Medline, Embase, PubMed, and Scopus databases. Studies using bulk tissue, animal tissue, whole bone, or testing techniques other than compression testing were excluded.Objectives
Methods
Patients with flexion instability after total knee arthroplasty
(TKA) often present with a recurrent effusion, which may be a haemarthrosis.
While the radiographic factors contributing to flexion instability
have been elucidated, the clinical diagnosis remains challenging.
Our aim, in this study, was to determine the mean white cell count
and differential profile in pre-operative aspirations of synovial
fluid in a consecutive series of patients undergoing revision TKA
for flexion instability. Between 2000 and 2010, 60 patients undergoing aseptic revision
TKA for flexion instability were identified. The results of the
pre-operative aspiration of synovial fluid were available for 53
patients (88%). These patients were 1:2 matched to 106 patients
who underwent aseptic TKA for indications other than flexion instability.
The mean age of the patients at revision TKA was 65 years (44 to
82) and 55% were women. The mean follow-up was 4.3 years (2 to 10.2).Aims
Patients and Methods
We have studied the beneficial effects of a hydroxyapatite (HA) coating on the prevention of the migration of
Magnetically controlled growing rod (MCGR) systems use non-invasive
spinal lengthening for the surgical treatment of early-onset scoliosis
(EOS). The primary aim of this study was to evaluate the performance
of these devices in the prevention of progression of the deformity.
A secondary aim was to record the rate of complications. An observational study of 31 consecutive children with EOS, of
whom 15 were male, who were treated between December 2011 and October
2017 was undertaken. Their mean age was 7.7 years (2 to 14). The
mean follow-up was 47 months (24 to 69). Distractions were completed
using the tailgating technique. The primary outcome measure was
correction of the radiographic deformity. Secondary outcomes were
growth, functional outcomes and complication rates.Aims
Patients and Methods
Metal-on-metal (MOM) bearings for hip arthroplasty are increasing in popularity. Concern remains, however, regarding the potential toxicological effects of the metal ions which these bearings release. The serum levels of cobalt and chromium in 22 patients who had undergone MOM resurfacing arthroplasty were compared with a matched group of 22 patients who had undergone 28 mm MOM total hip arthroplasty (THA). At a median of 16 months (7 to 56) after resurfacing arthroplasty, we found the median serum levels of cobalt and chromium to be 38 nmol/l (14 to 44) and 53 nmol/l (23 to 165) respectively. These were significantly greater than the levels after 28 mm MOM THA which were 22 nmol/l (15 to 87, p = 0.021) and 19 nmol/l (2 to 58, p <
0.001) respectively. Since the upper limit for normal patients without implants is typically 5 nmol/l, both groups had significantly raised levels of metal ions. MOM bearings of large diameter, however, result in a greater systemic exposure of cobalt and chromium ions than bearings of small diameter. This may be of relevance for potential long-term side-effects. It is not known to what extent this difference is due to corrosion of the surfaces of the component or of the
The aims of this study were to determine the proportion of patients
with outlier varus or valgus alignment in kinematically aligned
total knee arthroplasty (TKA), whether those with outlier varus
or valgus alignment have higher forces in the medial or lateral
compartments of the knee than those with in-range alignment and
whether measurements of the alignment of the limb, knee and components
predict compartment forces. The intra-operative forces in the medial and lateral compartments
were measured with an instrumented tibial insert in 67 patients
who underwent a kinematically aligned TKA during passive movement.
The mean of the forces at full extension, 45° and 90° of flexion
determined the force in the medial and lateral compartments. Measurements
of the alignment of the limb and the components included the hip-knee-ankle
(HKA) angle, proximal medial tibial angle (PMTA), and distal lateral
femoral angle (DLFA). Measurements of the alignment of the knee
and the components included the tibiofemoral angle (TFA), tibial
component angle (TCA) and femoral component angle (FCA). Alignment was
measured on post-operative, non-weight-bearing anteroposterior (AP)
scanograms and categorised as varus or valgus outlier or in-range
in relation to mechanically aligned criteria.Aims
Patients and Methods
Periprosthetic joint infection (PJI) is a serious complication
of total hip arthroplasty (THA). Different bearing surface materials
have different surface properties and it has been suggested that
the choice of bearing surface may influence the risk of PJI after
THA. The objective of this meta-analysis was to compare the rate
of PJI between metal-on-polyethylene (MoP), ceramic-on-polyethylene
(CoP), and ceramic-on-ceramic (CoC) bearings. Electronic databases (Medline, Embase, Cochrane library, Web
of Science, and Cumulative Index of Nursing and Allied Health Literature)
were searched for comparative randomized and observational studies
that reported the incidence of PJI for different bearing surfaces.
Two investigators independently reviewed studies for eligibility, evaluated
risk of bias, and performed data extraction. Meta-analysis was performed
using the Mantel–Haenzel method and random-effects model in accordance
with methods of the Cochrane group.Aims
Patients and Methods
We reviewed the radiographs of 864 Charnley and STH (Zimmer) cemented total hip arthroplasties with a mean follow-up of seven years (maximum 16 years). Survivorship analysis was used to assess the correlation between radiographic performance and the bony containment or the coronal orientation of the acetabular cup. The cup orientation and containment were interrelated; all vertically oriented cups were completely contained, whereas 25% of more horizontal cups were only partially contained. Completely contained cups had significantly lower incidences of complete cement-bone radiolucency (p = 0.02) and of
Between 1990 and 1992, we implanted 71 hybrid alumina-on-alumina hip arthroplasties in 62 consecutive patients under the age of 55 years, with a mean age of 46 years at surgery. There were 56 primary and 15 secondary procedures. The prostheses involved a cemented titanium alloy stem, a 32 mm alumina head, and a press-fit metal-backed socket with an alumina insert. Three patients (four hips) died from unrelated causes. Four hips had revision surgery for either deep infection, unexplained persistent pain, fracture of the alumina head, or aseptic loosening of the socket. The nine-year survival rate was 93.7% with revision for any cause as the end-point and 98.4% with revision for aseptic loosening as the end-point. The outcome in the surviving patients (50 patients, 57 hips) with a minimum five-year follow-up (mean eight years) was excellent in 47 hips (82.5%), very good in eight (14%), good in one and fair in one. A thin, partial, lucent line, mainly in zone III was present in 38% of the sockets and one socket had a complete lucency less than 1 mm thick. One stem had isolated femoral osteolysis. There was no detectable component migration nor acetabular osteolysis. This hybrid arthroplasty gave satisfactory medium-term results in active patients. The press-fit metal-backed socket appeared to have reliable fixation in alumina-on-alumina hip arthroplasty. The excellent results using cemented fixation of the stem may be related to the low production of
What represents clinically significant acetabular undercoverage
in patients with symptomatic cam-type femoroacetabular impingement
(FAI) remains controversial. The aim of this study was to examine
the influence of the degree of acetabular coverage on the functional
outcome of patients treated arthroscopically for cam-type FAI. Between October 2005 and June 2016, 88 patients (97 hips) underwent
arthroscopic cam resection and concomitant labral debridement and/or
refixation. There were 57 male and 31 female patients with a mean
age of 31.0 years (17.0 to 48.5) and a mean body mass index (BMI)
of 25.4Â kg/m2 (18.9 to 34.9). We used the Hip2Norm, an
object-oriented-platform program, to perform 3D analysis of hip
joint morphology using 2D anteroposterior pelvic radiographs. The lateral
centre-edge angle, anterior coverage, posterior coverage, total
femoral coverage, and alpha angle were measured for each hip. The
presence or absence of crossover sign, posterior wall sign, and
the value of acetabular retroversion index were identified automatically
by Hip2Norm. Patient-reported outcome scores were collected preoperatively
and at final follow-up with the Hip Disability and Osteoarthritis
Outcome Score (HOOS).Aims
Patients and Methods
Fretting and corrosion at the modular head/neck junction, known
as trunnionosis, in total hip arthroplasty (THA) is a cause of adverse
reaction to metal debris (ARMD). We describe the outcome of revision
of metal-on-polyethylene (MoP) THA for ARMD due to trunnionosis
with emphasis on the risk of major complications. A total of 36 patients with a MoP THA who underwent revision
for ARMD due to trunnionosis were identified. Three were excluded
as their revision had been to another metal head. The remaining
33 were revised to a ceramic head with a titanium sleeve. We describe
the presentation, revision findings, and risk of complications in
these patients.Aims
Patients and Methods
1. In a prospective study of sixty patients with cerebral palsy and contracture of the hamstrings, 112 operations were performed by three different techniques after any necessary correction of flexion contracture of the hip or equinus of the ankle. 2. Transposition by the method of Eggers has been abandoned because simple lengthening has been found to have several advantages. 3. Proximal lengthening, at or near the ischial tuberosity, is employed when fixed flexion of the knee does not exceed 5 degrees, and is now the standard method. A transverse incision in the natal fold avoids cheloid formation. 4. Distal lengthening behind the knee is reserved for cases in which the fixed flexion exceeds 5 degrees. 5. After lengthening and weakening of the hamstrings, these spastic patients could stand more easily and walk with straighter knees, the length ofstride became greater, stairs could be climbed more easily, the feet could be lifted more from the ground, and the
Many case reports and small studies have suggested that cobalt
ions are a potential cause of cardiac complications, specifically
cardiomyopathy, after metal-on-metal (MoM) total hip arthroplasty
(THA). The impact of metal ions on the incidence of cardiac disease
after MoM THA has not been evaluated in large studies. The aim of
this study was to compare the rate of onset of new cardiac symptoms
in patients who have undergone MoM THA with those who have undergone
metal-on-polyethylene (MoP) THA. Data were extracted from the Standard Analytics Files database
for patients who underwent MoM THA between 2005 and 2012. Bearing
surface was selected using International Classification of Diseases
ninth revision codes. Patients with a minimum five-year follow-up
were selected. An age and gender-matched cohort of patients who underwent
MoP THA served as a comparison group. New diagnoses of cardiac disease
were collected during the follow-up period. Comorbidities and demographics
were identified and routine descriptive statistics were used.Aims
Patients and Methods
The aims of this study were to determine the clinical and radiographic
outcomes, implant survivorship, and complications of patients with
a history of poliomyelitis undergoing total hip arthroplasty (THA)
in affected limbs and unaffected limbs of this same population. A retrospective review identified 51 patients (27 male and 24
female, 59 hips) with a mean age of 66 years (38 to 88) and with
the history of poliomyelitis who underwent THA for degenerative
arthritis between 1970 and 2012. Immigrant status, clinical outcomes,
radiographic results, implant survival, and complications were recorded.Aims
Patients and Methods
1. Clinically, hallux rigidus is a painful condition of the joints of the great toe associated with loss of dorsiflexion of the first phalanx. 2. Pathologically, the morbid changes are those of a traumatic synovitis followed by an early development of osteoarthritis, the initial lesions of which are erosions of the cartilage at the centre and near the dorsal margin of the base of the proximal phalanx. There is no fundamental pathological difference between the adult and adolescent varieties of hallux ngidus. Both represent stages in the developmental cycle of osteoarthritis in the proximal joint of the great toe. 3. The radiographic density and apparent fragmentation of the phalangeal epiphysis do not represent an abnormality of the bone and have no significance in the etiology of hallux rigidus. 4. The cause of hallux rigidus is an abnormal gait developed either to protect an injured or inflamed metatarso-phalangeal joint from the pressure of weight-bearing, or to stabilise a hypermobile first metatarsal. The effects of this gait are to transfer most of the pressure from the flexor brevis tendon and the two sesamoids to the base of the first phalanx. Excessive pressure on this joint predisposes to osteoarthritis. 5. Evidence of this abnormal gait is found in the peculiarities of
We reviewed retrospectively 22 patients (23 limb segments) with fibular hemimelia treated by amputation or limb lengthening to evaluate these methods of treatment. There were 12 boys and 10 girls, all with associated anomalies in the lower limbs. Twelve patients (13 limb segments) had early amputation and prosthetic fitting and ten had tibial lengthening using the Ilizarov technique. At the latest follow-up, the twelve patients who had amputation were functioning well and had few complications. The ten patients who had lengthening had suffered numerous complications, and all had needed either further corrective surgery or to
Patient-specific (PS) implantation surgical technology has been introduced in recent years and a gradual increase in the associated number of surgical cases has been observed. PS technology uses a patient’s own geometry in designing a medical device to provide minimal bone resection with improvement in the prosthetic bone coverage. However, whether PS unicompartmental knee arthroplasty (UKA) provides a better biomechanical effect than standard off-the-shelf prostheses for UKA has not yet been determined, and still remains controversial in both biomechanical and clinical fields. Therefore, the aim of this study was to compare the biomechanical effect between PS and standard off-the-shelf prostheses for UKA. The contact stresses on the polyethylene (PE) insert, articular cartilage and lateral meniscus were evaluated in PS and standard off-the-shelf prostheses for UKA using a validated finite element model. Gait cycle loading was applied to evaluate the biomechanical effect in the PS and standard UKAs.Objectives
Methods