Aims. Cementing in
Aims. The aim of this study was to estimate time to
Aims. To our knowledge, no study has compared the long-term results of cemented and hybrid total hip arthroplasty (THA) in patients with osteoarthritis (OA) secondary to congenital hip disease (CHD). This is a demanding procedure that may require special techniques and implants. Our aim was to compare the long-term outcome of cemented low-friction
Aims. Custom-made partial pelvis
Aims. The purpose of this study was to determine the access to and ability to use telemedicine technology in adult patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA), and to determine associations with the socioeconomic characteristics of the patients, including age, sex, race, and education. We also sought to understand the patients’ perceived benefits, risks, and preferences when dealing with telemedicine. Methods. We performed a cross-sectional survey involving patients awaiting primary THA and TKA by one of six surgeons at a single academic institution. Patients were included and called for a telephone-administered survey if their surgery was scheduled to be between 23 March and 2 June 2020, and were aged > 18 years. Results. The response rate was 52% (189 of 363 patients). A total of 170 patients (90.4%) reported using the internet, 177 (94.1%) reported owning a device capable of videoconferencing, and 143 (76.1%) had participated in a video call in the past year. When asked for their preferred method for a consultation, 155 (82.8%) and 26 (13.9%) ranked in-person and a videoconference as their first choice, respectively. The perceived benefits of telemedicine consultations included reduced travel to appointments (165 (88.2%) agreed) and reduced cost of attending appointments (123 (65.8%) agreed). However, patients were concerned that they would not establish the same patient-physician connection (100 (53.8%) agreed), and would not receive the same level of care (52 (33.2%) agreed) using telemedicine consultations compared with in-person consultations. Conclusion. Most patients undergoing
Aims. The aim of the HIPGEN consortium is to develop the first cell therapy product for hip fracture patients using PLacental-eXpanded (PLX-PAD) stromal cells. Methods. HIPGEN is a multicentre, multinational, randomized, double-blind, placebo-controlled trial. A total of 240 patients aged 60 to 90 years with low-energy femoral neck fractures (FNF) will be allocated to two arms and receive an intramuscular injection of either 150 × 10. 6. PLX-PAD cells or placebo into the medial gluteal muscle after direct lateral implantation of total or hemi hip arthroplasty. Patients will be followed for two years. The primary endpoint is the Short Physical Performance Battery (SPPB) at week 26. Secondary and exploratory endpoints include morphological parameters (lean body mass), functional parameters (abduction and handgrip strength, symmetry in gait, weightbearing), all-cause mortality rate and patient-reported outcome measures (Lower Limb Measure, EuroQol five-dimension questionnaire). Immunological biomarker and in vitro studies will be performed to analyze the PLX-PAD mechanism of action. A sample size of 240 subjects was calculated providing 88% power for the detection of a 1 SPPB point treatment effect for a two-sided test with an α level of 5%. Conclusion. The HIPGEN study assesses the efficacy, safety, and tolerability of intramuscular PLX-PAD administration for the treatment of muscle injury following
Aims. The aim of this study was to determine whether patients with
metal-on-metal (MoM)
Aims. Routine surveillance of primary hip and knee arthroplasties has traditionally been performed with office follow-up visits at one year postoperatively. The value of these visits is unclear. The present study aims to determine the utility and burden of routine clinical follow-up at one year after primary
Aims. 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. Materials and Methods. 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). Results. Hip resurfacing provided a near-native ROM with between 5° to 17° increase in IR/ER ROM compared with the native hip for the different positions tested, which was a 9% to 33% increase. DM-THA generated a 9° to 61° (18% to 121%) increase in ROM. Conventional THA generated a 52° to 100° (94% to 199%) increase in ROM. Thus, for conventional THA, the capsule function that exerts a limit on ROM is lost. It is restored to some extent by DM-THA, and almost fully restored by hip resurfacing. In positions of low flexion/extension, the posterior capsulotomy provided more normal function than the anterior, possibly because the capsule was shortened during posterior repair. However, in deep flexion positions, the anterior capsulotomy functioned better. Conclusion. Native head-size and capsular repair preserves capsular function after
Aims. Natural Language Processing (NLP) offers an automated method to extract data from unstructured free text fields for arthroplasty registry participation. Our objective was to investigate how accurately NLP can be used to extract structured clinical data from unstructured clinical notes when compared with manual data extraction. Methods. A group of 1,000 randomly selected clinical and hospital notes from eight different surgeons were collected for patients undergoing primary
In Africa the amount of
Arthroscopy of the native hip is an established diagnostic and therapeutic procedure. Its application in the symptomatic replaced hip is still being explored. We describe the use of arthroscopy of the hip in 24 symptomatic patients following total hip replacement, resurfacing
Aims. Our aim was to examine the Elixhauser and Charlson comorbidity indices, based on administrative data available before surgery, and to establish their predictive value for mortality for patients who underwent hip arthroplasty in the management of a femoral neck fracture. Patients and Methods. We analyzed data from 42 354 patients from the Swedish Hip Arthroplasty Register between 2005 and 2012. Only the first operated hip was included for patients with bilateral
Nerve palsy is a well-described complication
following total hip arthroplasty, but is highly distressing and
disabling. A nerve palsy may cause difficulty with the post-operative
rehabilitation, and overall mobility of the patient. Nerve palsy
may result from compression and tension to the affected nerve(s)
during the course of the operation via surgical manipulation and
retractor placement, tension from limb lengthening or compression
from post-operative hematoma. In the literature, hip dysplasia,
lengthening of the leg, the use of an uncemented femoral component, and
female gender are associated with a greater risk of nerve palsy.
We examined our experience at a high-volume, tertiary care referral
centre, and found an overall incidence of 0.3% out of 39 056 primary
hip
We studied survival to 38 years after Charnley low-friction
As adverse events related to metal on metal hip
arthroplasty have been better understood, there has been increased
interest in toxicity related to the high circulating levels of cobalt ions.
However, distinguishing true toxicity from benign elevations in
cobalt levels can be challenging. The purpose of this review is
to examine the use of cobalt alloys in total hip arthroplasty, to
review the methods of measuring circulating cobalt levels, to define
a level of cobalt which is considered pathological and to review
the pathophysiology, risk factors and treatment of cobalt toxicity.
To the best of our knowledge, there are 18 published cases where
cobalt metal ion toxicity has been attributed to the use of cobalt-chromium
alloys in hip arthroplasty. Of these cases, the great majority reported
systemic toxic reactions at serum cobalt levels more than 100 μg/L.
This review highlights some of the clinical features of cobalt toxicity,
with the goal that early awareness may decrease the risk factors
for the development of cobalt toxicity and/or reduce its severity. Take home message: Severe adverse events can arise from the release
of cobalt from metal-on-metal
Objectives. The primary aim of this study was to assess the reproducibility of the recalled preoperative Oxford Hip Score (OHS) and Oxford Knee Score (OKS) one year following
Aims. For this retrospective cohort study, patients aged ≤ 30 years
(very young) who underwent total hip arthroplasty (THA) were compared
with patients aged ≥ 60 years (elderly) to evaluate the rate of
revision
In patients with severe quadriplegic cerebral palsy and painful hip dislocation proximal femoral resection
We reviewed 261 patients with 320 Charnley low-friction
Few independent studies have reported the outcome of resurfacing
We evaluated the potential of a vastus lateralis muscle flap in controlling infection after resection
We used Laser Doppler flowmetry to measure the effect on the blood flow to the femoral head/neck junction of two surgical approaches during resurfacing
We reviewed 508 consecutive total hip replacements in 370 patients with old developmental dysplasia of the hip, to relate the amount of leg lengthening to the incidence of nerve palsies after operation. There were eight nerve palsies (two femoral, six sciatic), two complete and six incomplete. We found no statistical correlation between the amount of lengthening and the incidence of nerve damage (p = 0.47), but in seven of the eight hips, the surgeon had rated the intervention as difficult because of previous surgery, severe deformity, a defect of the acetabular roof, or considerable flexion deformity. The correlation between difficulty and nerve palsy was significant (p = 0.041). We conclude that nerve injury is most commonly caused by direct or indirect mechanical trauma and not by limb lengthening on its own.
Of the 11 054 Charnley low-frictional torque
Patient safety is a critical issue in elective
total
We performed 96 Birmingham resurfacing
Aims. The place of thromboprophylaxis in
The orientation of the acetabular component is
influenced not only by the orientation at which the surgeon implants
the component, but also the orientation of the pelvis at the time
of implantation. Hence, the orientation of the pelvis at set-up
and its movement during the operation, are important. During 67
hip
Increasing follow-up identifies the outcome in younger patients who have undergone total hip replacement (THR) and reveals the true potential for survival of the prosthesis. We identified 28 patients (39 THRs) who had undergone cemented Charnley low friction
Resurfacing
Arthroplasty registries are important for the
surveillance of
We report the long-term results of revision total
hip
We evaluated the outcome of 41 consecutive Charnley
low-friction
Narrowing of the femoral neck after resurfacing
Increased concentrations of metal ions after metal-on-metal resurfacing
During hip resurfacing arthroplasty, excessive valgus positioning or surgical technique can result in notching of the femoral neck. Although mechanical weakening and subsequent fracture of the femoral neck are well described, the potential damage to the retinacular vessels leading to an ischaemic event is relatively unknown. Using laser Doppler flowmetry, we measured the blood flow in 14 osteoarthritic femoral heads during routine total hip replacement surgery, before and after notching of the femoral neck. In ten hips there was a reduction in blood flow of more than 50% from the baseline value after simulated notching of the femoral neck. Our results suggest that femoral head vascularity in the osteoarthritic state is similar to the non-arthritic state, where damage to the extraosseous vessels can predispose to avascular necrosis. Surgeons who perform resurfacing
Patients from a randomised trial on resurfacing
hip
The early designs of hip resurfacing implants suffered high rates of early failure, making it impossible to obtain valuable mid-term radiostereophotogrammetric (RSA) results. The metal-on-metal Birmingham Hip Resurfacing
Between 1981 and 1986 two groups of patients received either Charnley low-friction
We present the histological findings of bone retrieved from beneath the femoral components of failed metal-on-metal hip resurfacing arthroplasties. Of a total of 377 patients who underwent resurfacing
We report a prospective study of the use of intramedullary bone blocks to improve the fixation of a matt-finish femoral stem in Charnley low-friction
The treatment of substantial proximal femoral
bone loss in young patients with developmental dysplasia of the
hip (DDH) is challenging. We retrospectively analysed the outcome
of 28 patients (30 hips) with DDH who underwent revision total hip
replacement (THR) in the presence of a deficient proximal femur,
which was reconstructed with an allograft prosthetic composite.
The mean follow-up was 15 years (8.5 to 25.5). The mean number of
previous THRs was three (1 to 8). The mean age at primary THR and
at the index reconstruction was 41 years (18 to 61) and 58.1 years
(32 to 72), respectively. The indication for revision included mechanical
loosening in 24 hips, infection in three and peri-prosthetic fracture
in three. Six patients required removal and
Symptomatic cobalt toxicity from a failed total
hip
We reviewed 249 consecutive Charnley primary low-friction
Between 1983 and 1988 we carried out 45 Charnley low-friction
Revision total hip replacement (THR) for young
patients is challenging because of technical complexity and the potential
need for subsequent further revisions. We have assessed the survivorship,
functional outcome and complications of this procedure in patients
aged <
50 years through a large longitudinal series with consistent treatment
algorithms. Of 132 consecutive patients (181 hips) who underwent
revision THR, 102 patients (151 hips) with a mean age of 43 years
(22 to 50) were reviewed at a mean follow-up of 11 years (2 to 26)
post-operatively. We attempted to restore bone stock with allograft
where indicated. Using further revision for any reason as an end point,
the survival of the acetabular component was 71% (. sd. 4)
and 54% (. sd. 7) at ten- and 20 years. The survival of the
femoral component was 80% (. sd. 4) and 62% (. sd. 6)
at ten- and 20 years. Complications included 11 dislocations (6.1%),
ten periprosthetic fractures (5.5%), two deep infections (1.1%),
four sciatic nerve palsies (2.2%; three resolved without intervention,
one improved after exploration and freeing from adhesions) and one
vascular injury (0.6%). The mean modified Harris Hip Score was 41
(10 to 82) pre-operatively, 77 (39 to 93) one year post-operatively
and 77 (38 to 93) at the latest review. This overall perspective on the mid- to long-term results is
valuable when advising young patients on the prospects of revision
surgery at the time of primary
Femoral impaction bone grafting was first developed in 1987 using
morselised cancellous bone graft impacted into the femoral canal
in combination with a cemented, tapered, polished stem. We describe
the evolution of this technique and instrumentation since that time. Between 1987 and 2005, 705 revision total hip arthroplasties
(56 bilateral) were performed with femoral impaction grafting using
a cemented femoral stem. All surviving patients were prospectively
followed for a mean of 14.7 years (9.8 to 28.3) with no loss to
follow-up. By the time of the final review, 404 patients had died.Aims
Patients 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
We report the results of our continued review of 14 hip arthroplasties using alumina ceramic femoral heads with cross-linked polyethylene cups. There have been no complications and a very low rate of penetration. This was 0.02 mm per year after an initial ‘bedding-in’ period of two years. There has been no change in the mean rate between our earlier study at six years and the current results at 10 to 11 years. The use of these bearing surfaces appears to reduce the potential amount of polyethylene debris and may provide the next logical stage in the development of the Charnley low-friction
The leading indication for revision total hip
arthroplasty (THA) remains aseptic loosening owing to wear. The younger,
more active patients currently undergoing THA present unprecedented
demands on the bearings. Ceramic-on-ceramic (CoC) bearings have
consistently shown the lowest rates of wear. The recent advances,
especially involving alumina/zirconia composite ceramic, have led
to substantial improvements and good results Alumina/zirconia composite ceramics are extremely hard, scratch
resistant and biocompatible. They offer a low co-efficient of friction
and superior lubrication and lower rates of wear compared with other
bearings. The major disadvantage is the risk of fracture of the
ceramic. The new composite ceramic has reduced the risk of fracture
of the femoral head to 0.002%. The risk of fracture of the liner
is slightly higher (0.02%). Assuming that the components are introduced without impingement,
CoC bearings have major advantages over other bearings. Owing to
the superior hardness, they produce less third body wear and are
less vulnerable to intra-operative damage. The improved tribology means that CoC bearings are an excellent
choice for young, active patients requiring THA. Cite this article:
Between November 1962 and December1990 a group of 1092 patients, 668 women and 424 men, under the age of 51 years at the time of surgery, underwent 1434 primary Charnley low-frictional torque
In this prospective study a total of 80 consecutive
Chinese patients with Crowe type I or II developmental dysplasia of
the hip were randomly assigned for hip resurfacing arthroplasty
(HRA) or total hip replacement (THR). Three patients assigned to HRA were converted to THR, and three
HRA patients and two THR patients were lost to follow-up. This left
a total of 34 patients (37 hips) who underwent HRA and 38 (39 hips)
who underwent THR. The mean follow-up was 59.4 months (52 to 70)
in the HRA group and 60.6 months (50 to 72) in the THR group. There was
no failure of the prosthesis in either group. Flexion of the hip
was significantly better after HRA, but there was no difference
in the mean post-operative Harris hip scores between the groups.
The mean size of the acetabular component in the HRA group was significantly
larger than in the THR group (49.5 mm vs 46.1 mm, p = 0.001). There was
no difference in the mean abduction angle of the acetabular component
between the two groups. Although the patients in this series had risk factors for failure
after HRA, such as low body weight, small femoral heads and dysplasia,
the clinical results of resurfacing in those with Crowe type I or
II hip dysplasia were satisfactory. Patients in the HRA group had
a better range of movement, although neck-cup impingement was observed.
However, more acetabular bone was sacrificed in HRA patients, and
it is unclear whether this will have an adverse effect in the long
term.
Revision of a cemented hemiarthroplasty of the
hip may be a hazardous procedure with high rates of intra-operative complications.
Removing well-fixed cement is time consuming and risks damaging
already weak bone or perforating the femoral shaft. The cement-in-cement
method avoids removal of intact cement and has shown good results
when used for revision total hip arthroplasty (THA). The use of
this technique for the revision of a hemiarthroplasty to THA has
not been previously reported. A total of 28 consecutive hemiarthroplasties (in 28 patients)
were revised to a THA using an Exeter stem and the cement-in-cement
technique. There were four men and 24 women; their mean age was
80 years (35 to 93). Clinical and radiographic data, as well as
operative notes, were collected prospectively and no patient was
lost to follow-up. Four patients died within two years of surgery. The mean follow
up of the remainder was 70 months (25 to 124). Intra-operatively
there was one proximal perforation, one crack of the
femoral calcar and one acetabular fracture. No femoral components
have required subsequent revision for aseptic loosening or are radiologically loose. Four patients with late complications (14%) have since undergone
surgery (two for a peri-prosthetic fracture, and one each for deep
infection and recurrent dislocation) resulting in an overall major
rate of complication of 35.7%. The cement-in-cement technique provides reliable femoral fixation
in this elderly population and may reduce operating time and rates
of complication. Cite this article:
Valid and reliable techniques for assessing performance
are essential to surgical education, especially with the emergence
of competency-based frameworks. Despite this, there is a paucity
of adequate tools for the evaluation of skills required during joint
replacement surgery. In this scoping review, we examine current
methods for assessing surgeons’ competency in joint replacement
procedures in both simulated and clinical environments. The ability
of many of the tools currently in use to make valid, reliable and
comprehensive assessments of performance is unclear. Furthermore,
many simulation-based assessments have been criticised for a lack
of transferability to the clinical setting. It is imperative that
more effective methods of assessment are developed and implemented
in order to improve our ability to evaluate the performance of skills
relating to total joint replacement. This will enable educators
to provide formative feedback to learners throughout the training
process to ensure that they have attained core competencies upon
completion of their training. This should help ensure positive patient
outcomes as the surgical trainees enter independent practice. Cite this article:
The purpose of this study was twofold: first,
to determine whether the five-year results of hip resurfacing arthroplasty
(HRA) in Canada justified the continued use of HRA; and second,
to identify whether greater refinement of patient selection was
warranted. This was a retrospective cohort study that involved a review
of 2773 HRAs performed between January 2001 and December 2008 at
11 Canadian centres. Cox’s proportional hazards models were used
to analyse the predictors of failure of HRA. Kaplan–Meier survival
analysis was performed to predict the cumulative survival rate at
five years. The factors analysed included age, gender, body mass
index, pre-operative hip pathology, surgeon’s experience, surgical
approach, implant sizes and implant types. The most common modes
of failure were also analysed. The 2773 HRAs were undertaken in 2450 patients: 2127 in men and
646 in women. The mean age at operation was 50.5 years ( The failure rates of HRA at five years justify the ongoing use
of this technique in men. Female gender is an independent predictor
of failure, and a higher failure rate at five years in women leads
the authors to recommend this technique only in exceptional circumstances
for women. Cite this article:
The purpose of this study was to examine the
complications and outcomes of total hip replacement (THR) in super-obese
patients (body mass index (BMI) >
50 kg/m2) compared
with class I obese (BMI 30 to 34.9 kg/m2) and normal-weight
patients (BMI 18.5 to 24.9 kg/m2), as defined by the
World Health Organization. A total of 39 THRs were performed in 30 super-obese patients
with a mean age of 53 years (31 to 72), who were followed for a
mean of 4.2 years (2.0 to 11.7). This group was matched with two
cohorts of normal-weight and class I obese patients, each comprising
39 THRs in 39 patients. Statistical analysis was performed to determine differences
among these groups with respect to complications and satisfaction
based on the Western Ontario and McMaster Universities (WOMAC) osteoarthritis
index, the Harris hip score (HHS) and the Short-Form (SF)-12 questionnaire. Super-obese patients experienced significantly longer hospital
stays and higher rates of major complications and readmissions than
normal-weight and class I obese patients. Although super-obese patients
demonstrated reduced pre-operative and post-operative satisfaction
scores, there was no significant difference in improvement, or change in
the score, with respect to HHS or the WOMAC osteoarthritis index. Super-obese patients obtain similar satisfaction outcomes as
class I obese and normal-weight patients with respect to improvement
in their scores. However, they experience a significant increase
in length of hospital stay and major complication and readmission
rates. Cite this article:
Persistent groin pain after seemingly successful
total hip replacement (THR) appears to have become more common.
Recent studies have indicated a high incidence after metal-on-polyethylene
and metal-on-metal conventional THR and it has been documented in
up to 18% of patients after metal-on-metal resurfacing. There are many
causes, including acetabular loosening, stress fracture, and iliopsoas
tendonitis and impingement. The evaluation of this problem requires
a careful history and examination, plain radiographs and an algorithmic approach
to special diagnostic imaging and tests. Non-operative treatment
is not usually successful. Specific operative treatment depending
on the cause of the pain usually involves revision of the acetabular
component, iliopsoas tenotomy or other procedures, and is usually
successful. Here, an appropriate algorithm is described.
A total of 31 patients, (20 women, 11 men; mean
age 62.5 years old; 23 to 81), who underwent conversion of a Girdlestone
resection-arthroplasty (RA) to a total hip replacement (THR) were
compared with 93 patients, (60 women, 33 men; mean age 63.4 years
old; 20 to 89), who had revision THR surgery for aseptic loosening
in a retrospective matched case-control study. Age, gender and the
extent of the pre-operative bone defect were similar in all patients.
Mean follow-up was 9.3 years (5 to 18). Pre-operative function and range of movement were better in the
control group (p = 0.01 and 0.003, respectively) and pre-operative
leg length discrepancy (LLD) was greater in the RA group (p <
0.001). The post-operative clinical outcome was similar in both
groups except for mean post-operative LLD, which was greater in
the study group (p = 0.003). There was a significant interaction
effect for LLD in the study group (p <
0.001). A two-way analysis
of variance showed that clinical outcome depended on patient age
(patients older than 70 years old had worse pre-operative pain,
p = 0.017) or bone defect (patients with a large acetabular bone
defect had higher LLD, p = 0.006, worse post-operative function
p = 0.009 and range of movement, p = 0.005), irrespective of the
group. Despite major acetabular and femoral bone defects requiring complex
surgical reconstruction techniques, THR after RA shows a clinical
outcome similar to those obtained in aseptic revision surgery for
hips with similar sized bone defects. Cite this article:
If a surgeon is faced with altered lesser trochanter
anatomy when revising the femoral component in revision total hip
replacement, a peri-prosthetic fracture, or Paprosky type IIIb or
type IV femoral bone loss, a modular tapered stem offers the advantages
of accurately controlling femoral version and length. The splines
of the taper allow rotational control, and improve the fit in femoral
canals with diaphyseal bone loss. In general, two centimetres of diaphyseal
contact is all that is needed to gain stability with modular tapered
stems. By allowing the proximal body trial to rotate on a well-fixed
distal segment during trial reduction, appropriate anteversion can
be obtained in order to improve intra-operative stability, and decrease
the dislocation risk. However, modular stems should not be used for
all femoral revisions, as implant fracture and corrosion at modular
junctions can still occur. Cite this article:
There is no consensus about the best method of achieving equal
leg lengths at total hip arthroplasty (THA) in patients with Crowe
type-IV developmental dysplasia of the hip (DDH). We reviewed our
experience of a consecutive series of patients who underwent THA
for this indication. We retrospectively reviewed 78 patients (86 THAs) with Crowe
type-IV DDH, including 64 women and 14 men, with a minimum follow-up
of two years. The mean age at the time of surgery was 52.2 years
(34 to 82). We subdivided Crowe type-IV DDH into two major types
according to the number of dislocated hips, and further categorised
them into three groups according to the occurrence of pelvic obliquity
or spinal curvature. Leg length discrepancy (LLD) and functional
scores were analysed.Aims
Patients and Methods
We have reviewed 42 patients who had revision of metal-on-metal resurfacing procedures, mostly because of problems with the acetabular component. The revisions were carried out a mean of 26.2 months (1 to 76) after the initial operation and most of the patients (30) were female. Malpositioning of the acetabular component resulted in 27 revisions, mostly because of excessive abduction (mean 69.9°; 56° to 98°) or insufficient or excessive anteversion. Seven patients had more than one reason for revision. The mean increase in the diameter of the component was 1.8 mm (0 to 4) when exchange was needed. Malpositioning of the components was associated with metallosis and a high level of serum ions. The results of revision of the femoral component to a component with a modular head were excellent, but four patients had dislocation after revision and four required a further revision.
Two-stage exchange remains the gold standard
for treatment of peri-prosthetic joint infection after total hip replacement
(THR). In the first stage, all components and associated cement
if present are removed, an aggressive debridement is undertaken
including a complete synovectomy, and an antibiotic-loaded cement
spacer is put in place. Patients are then treated with six weeks
of parenteral antibiotics, followed by an ‘antibiotic free period’
to help ensure the infection has been eradicated. If the clinical
evaluation and serum inflammatory markers suggest the infection
has resolved, then the second stage can be completed, which involves
removal of the cement spacer, repeat debridement, and placement
of a new THR. Cite this article:
Discrepancy in leg length after total hip replacement has been associated with patient dissatisfaction. We prospectively studied 200 consecutive patients undergoing unilateral Charnley hip replacements to identify whether there is a demonstrable association between such disparity and postoperative function. Radiological measurements between defined points on the pelvis and femur of the operated hip were compared with the same points on the contralateral joint. A lengthening index was derived and statistical analysis used to compare this with validated functional outcome scores (Harris hip score and the SF36 Health Survey) and patient satisfaction. Our results showed no statistical association between leg-length discrepancy after hip arthroplasty and functional outcome or patient satisfaction.
Direct anterior approaches to the hip have gained
popularity as a minimally invasive method when performing primary
total hip replacement (THR). A retrospective review of a single
institution joint registry was performed in order to compare patient
outcomes after THR using the Anterior Supine Intermuscular (ASI)
approach Cite this article
Radiostereometric analysis (RSA) can detect early
micromovement in unstable implant designs which are likely subsequently
to have a high failure rate. In 2010, the Articular Surface Replacement
(ASR) was withdrawn because of a high failure rate. In 19 ASR femoral
components, the mean micromovement over the first two years after implantation
was 0.107 mm ( We conclude that the ASR femoral component achieves initial stability
and that early migration is not the mode of failure for this resurfacing
arthroplasty.
We report serum metal ion level data in patients with unilateral and bilateral hip resurfacing over a ten-year period. In these patients there is an increase in both cobalt and chromium levels above the accepted reference ranges during the first 18 months after operation. Metal ion levels remain elevated, but decline slowly for up to five years. However, the levels then appear to start rising again in some patients up to the ten-year mark. There was no significant difference in cobalt or chromium levels between men and women. These findings appear to differ from much of the current literature. The clinical significance of a raised metal ion level remains under investigation.
The debate whether to use cemented or uncemented
components in primary total hip replacement (THR) has not yet been
considered with reference to the cost implications to the National
Health Service. We obtained the number of cemented and uncemented components
implanted in 2009 from the National Joint Registry for England and
Wales. The cost of each component was established. The initial financial
saving if all were cemented was then calculated. Subsequently the
five-year rates of revision for each type of component were reviewed
and the predicted number of revisions at five years for the actual
components used was compared with the predicted number of revisions
for a cemented THR. This was then multiplied by the mean cost of
revision surgery to provide an indication of the savings over the
first five years if all primary THRs were cemented. The saving at primary THR was calculated to be £10 million with
an additional saving during the first five years of between £5 million
and £8.5 million. The use of cemented components in routine primary
THR in the NHS as a whole can be justified on a financial level
but we recognise individual patient factors must be considered when deciding
which components to use.
The widely used and well-proven Palacos R (a.k.a. Refobacin Palacos
R) bone cement is no longer commercially available and was superseded
by Refobacin bone cement R and Palacos R + G in 2005. However, the
performance of these newly introduced bone cements have not been
tested in a phased evidence-based manner, including roentgen stereophotogrammetric
analysis (RSA). In this blinded, randomised, clinical RSA study, the migration
of the Stanmore femoral component was compared between Refobacin
bone cement R and Palacos R + G in 62 consecutive total hip arthroplasties.
The primary outcome measure was femoral component migration measured
using RSA and secondary outcomes were Harris hip score (HHS), Hip
disability and Osteoarthritis Outcome Score (HOOS), EuroQol 5D (EQ-5D)
and Short Form 36 (SF-36).Aims
Patients and Methods
The Unified Classification System (UCS) emphasises
the key principles in the assessment and management of peri-prosthetic
fractures complicating partial or total joint replacement. We tested the inter- and intra-observer agreement for the UCS
as applied to the pelvis and femur using 20 examples of peri-prosthetic
fracture in 17 patients. Each subtype of the UCS was represented
by at least one case. Specialist orthopaedic surgeons (experts)
and orthopaedic residents (pre-experts) assessed reliability on
two separate occasions. For the pelvis, the UCS showed inter-observer agreement of 0.837
(95% confidence intervals (CI) 0.798 to 0.876) for the experts and
0.728 (95% CI 0.689 to 0.767) for the pre-experts. The intra-observer
agreement for the experts was 0.861 (95% CI 0.760 to 0.963) and
0.803 (95% 0.688 to 0.918) for the pre-experts. For the femur, the
UCS showed an inter-observer kappa value of 0.805 (95% CI 0.765
to 0.845) for the experts and a value of 0.732 (95% CI 0.690 to 0.773)
for the pre-experts. The intra-observer agreement was 0.920 (95%
CI 0.867 to 0.973) for the experts, and 0.772 (95% CI 0.652 to 0.892)
for the pre-experts. This corresponds to a substantial and ‘almost
perfect’ inter- and intra-observer agreement for the UCS for peri-prosthetic
fractures of the pelvis and femur. We hope that unifying the terminology of these injuries will
assist in their assessment, treatment and outcome. Cite this article:
The orientation of the acetabular component can
influence both the short- and long-term outcomes of total hip replacement
(THR). We performed a prospective, randomised, controlled trial
of two groups, comprising of 40 patients each, in order to compare
freehand introduction of the component with introduction using the transverse
acetabular ligament (TAL) as a reference for anteversion. Anteversion
and inclination were measured on pelvic radiographs. With respect to anteversion, in the freehand group 22.5% of the
components were outside the safe zone With respect to inclination, in the freehand group 37.5% of the
components were outside the safe zone The transverse acetabular ligament may be used to obtain the
appropriate anteversion when introducing the acetabular component
during THR, but not acetabular component inclination. Cite this article:
After total hip and knee replacement arthoplasty, patients may become anaemic and may be prescribed oral iron. There is, however, no published evidence that this is of benefit when used postoperatively. We treated 72 patients who were anaemic after primary total hip and knee arthroplasty by randomly allocating them to receive six weeks of either oral ferrous sulphate (35 patients) or a placebo (37 patients). Both groups of patients were similar in all aspects except for the treatment given. There was no statistically significant difference in the change of haemoglobin levels between the two groups. We therefore believe that the prescription of iron to all anaemic patients postoperatively should be avoided. The level of serum ferritin should be monitored at preoperative assessment.
Between 1985 and 1993, 146 patients (162 hips) had total hip replacement (THR) using a conservative uncemented femoral component. The mean age of the patients was 50.8 years and the mean follow-up was 6.2 years (2 to 13). One patient was lost to follow-up, one died within two years of surgery and one had a revision procedure after a fracture sustained in a road-traffic accident. For the remaining 159, Kaplan-Meier survival analysis was calculated for the incidence of revision because of mechanical loosening or osteolysis. Survival without mechanical loosening at both five and ten years was 98.2%. Survival without osteolysis was 99% at five and 91% at ten years. The Harris hip score improved from a mean of 66.3 before to 90.4 at follow-up. Of particular note is the lack of thigh pain in this group. Radiological analysis showed that 139 stems (88%) had no measurable subsidence, 8 (5%) had less than 2 mm and 12 (7%) had more than 2 mm. Two of the eight and one of the 12 were revised for mechanical loosening. Nine hips were revised for late loosening associated with osteolysis. No reaming of the femoral canal was associated with statistically significant less blood loss compared with a comparable control group of uncemented implants (p <
0.0001). Our study suggests that using a conservative femoral implant does not protect against wear debris but the reliable mechanical stability (98.2%) makes this an attractive design of implant particularly for young patients.
We have assessed the usefulness of a regional hip register in the assessment of the outcome of primary total hip replacement (THR). Over 97% of THRs performed in the Trent region in 1990 were captured onto the register and the inaccuracies recorded were less than 1.8%. In an independent assessment of 2111 patients five years after THR, 85.9% of those available for assessment responded, and 66.8% agreed to an assessment. The cost of this independent assessment at five years, utilising a regional hip register, was approximately £50 per implant. This is a reasonable outlay to identify problems early. Some form of registration and outcome assessment should be performed on a national level.
This study reports the clinical outcome of reconstruction
of deficient abductor muscles following revision total hip arthroplasty
(THA), using a fresh–frozen allograft of the extensor mechanism
of the knee. A retrospective analysis was conducted of 11 consecutive
patients with a severe limp because of abductor deficiency which
was confirmed on MRI scans. The mean age of the patients (three
men and eight women) was 66.7 years (52 to 84), with a mean follow-up
of 33 months (24 to 41). Following surgery, two patients had no limp, seven had a mild
limp, and two had a persistent severe limp (p = 0.004). The mean
power of the abductors improved on the Medical Research Council
scale from 2.15 to 3.8 (p <
0.001). Pre-operatively, all patients
required a stick or walking frame; post-operatively, four patients
were able to walk without an aid. Overall, nine patients had severe
or moderate pain pre-operatively; ten patients had no or mild pain
post-operatively. At final review, the Harris hip score was good in five patients,
fair in two and poor in four. We conclude that using an extensor mechanism allograft is relatively
effective in the treatment of chronic abductor deficiency of the
hip after THA when techniques such as local tissue transfer are
not possible. Longer-term follow-up is necessary before the technique can be
broadly applied. Cite this article:
We report the results of our continued review of 11 total hip arthroplasties using 22.225 mm alumina ceramic femoral heads on a Charnley flanged stem, articulating with chemically cross-linked polyethylene. There was an initial bedding-in of up to 0.41 mm at the articular surface in the first two years. This had not progressed further, at a minimum follow-up of 15 years. Radiographically no femoral or acetabular component showed loosening or osteolysis.
Pre-operative planning for total hip replacement
(THR) is challenging in hips with severe acetabular deformities, including
those with a hypoplastic acetabulum or severe defects and in the
presence of arthrodesis or ankylosis. We evaluated whether a Rapid
Prototype (RP) model, which is a life-sized reproduction based on
three-dimensional CT scans, can determine the feasibility of THR
and provide information about the size and position of the acetabular component
in severe acetabular deformities. THR was planned using an RP model
in 21 complex hips in five men (five hips) and 16 women (16 hips)
with a mean age of 47.7 years (24 to 70) at operation. An acetabular
component was implanted successfully and THR completed in all hips.
The acetabular component used was within 2 mm of the predicted size
in 17 hips (80.9%). All of the acetabular components and femoral
stems had radiological evidence of bone ingrowth and stability at
the final follow-up, without any detectable wear or peri-prosthetic
osteolysis. The RP model allowed a simulated procedure pre-operatively
and was helpful in determining the feasibility of THR pre-operatively,
and to decide on implant type, size and position in complex THRs. Cite this article:
Muscle atrophy has been demonstrated in patients suffering from osteoarthritis of the hip, but little is known about muscular recovery after total hip replacement (THR). A total of 20 patients with unilateral osteoarthritis of the hip were assessed before, six months and two years after THR. The cross-sectional area and radiological density of the muscles of the hip, thigh, calf and back were measured using CT. We hypothesised that the muscles would not recover fully after operation. After two years comparison of the limb with the THR with the healthy limb showed that there was such a reduction in the cross-sectional area in iliopsoas (7.0%; p = 0.006) and the hip adductors (8.4%, p = 0.003) and in the radiological density in gluteus maximus (10.1 Hounsfield units; p <
0.001), gluteus medius/minimus (5.6 Hounsfield units; p = 0.011), iliopsoas (3.9 Hounsfield units; p <
0.001) and the adductors (2.4 Hounsfield units; p = 0.022). Thus, there was persistent muscle atrophy in muscles acting about the hip two years after THR. We suggest that an earlier operation or a more intensive rehabilitation may reverse these changes.
The primary aim of this study was to investigate the effect of
an enhanced recovery program (ERP) on the short-term functional
outcome after total hip arthroplasty (THA). Secondary outcomes included
its effect on rates of dislocation and mortality. Data were gathered on 1161 patients undergoing primary THA which
included 611 patients treated with traditional rehabilitation and
550 treated with an ERP. Aims
Patients and Methods
The highly cross-linked polyethylene Exeter RimFit flanged cemented
acetabular component was introduced in the United Kingdom in 2010.
This study aimed to examine the rates of emergence of radiolucent
lines observed when the Rimfit acetabular component was implanted
at total hip arthroplasty (THA) using two different techniques: firstly,
the ‘rimcutter’ technique in which the flange sits on a pre-prepared
acetabular rim; and secondly, the ‘trimmed flange’ technique in
which the flange is trimmed and the acetabular component is seated
inside the rim of the acetabulum. The radiographs of 150 THAs (75 ‘rimcutter’, 75 ‘trimmed flange’)
involving this component were evaluated to assess for radiolucencies
at the cement/bone interface by three observers. Aims
Patients and Methods
In this study we evaluated whether pre-operative
Western Ontario and McMaster Universities (WOMAC) osteoarthritis
scores can predict satisfaction following total hip arthroplasty
(THA). Prospective data for a cohort of patients undergoing THA
from two large academic centres were collected, and pre-operative
and one-year post-operative WOMAC scores and a 25-point satisfaction
questionnaire were obtained for 446 patients. Satisfaction scores
were dichotomised into either improvement or deterioration. Scatter
plots and Spearman’s rank correlation coefficient were used to describe
the association between pre-operative WOMAC and one-year post-operative WOMAC
scores and patient satisfaction. Satisfaction was compared using
receiver operating characteristic (ROC) analysis against pre-operative,
post-operative and δ WOMAC scores. We found no relationship between pre-operative WOMAC scores and
one-year post-operative WOMAC or satisfaction scores, with Spearman’s
rank correlation coefficients of 0.16 and –0.05, respectively. The
ROC analysis showed areas under the curve (AUC) of 0.54 (pre-operative
WOMAC), 0.67 (post-operative WOMAC) and 0.43 (δ WOMAC), respectively,
for an improvement in satisfaction. We conclude that the pre-operative WOMAC score does not predict
the post-operative WOMAC score or patient satisfaction after THA,
and that WOMAC scores can therefore not be used to prioritise patient
care. Cite this article:
We describe the results of 76 total arthroplasties of the hip for stage-III or stage-IV avascular necrosis of the femoral head. Harris Galante Porous cups were used in 63 patients between 1986 and 1994 and followed prospectively. We reviewed 70 hips with a follow-up of more than five years (mean 7.6). At the latest review the mean Harris Hip Score had improved from a preoperative value of 29 ± 14.7 to 94 ± 6.8. Radiologically, there was no evidence of acetabular migration. The rate of revision for the femoral component was 8.6%, three being undertaken for loosening and three to allow downsizing of the femoral head. The rate of revision for the acetabular component was 7.1% (five cups). At the time of revision none of the cups was clinically loose, and only required the liner to be changed. The rate of complications was low with no case of deep infection or dislocation, but nine of the 76 hips (11.8%) showed grade-III heterotopic ossification. Previous studies of patients undergoing cemented total hip arthroplasty for the treatment of advanced avascular necrosis have indicated a high incidence of loosening of the acetabular component. Our findings show good medium-term results using the Harris Galante Porous cup for acetabular reconstruction, together with a variety of cemented femoral components, for the treatment of this difficult problem.
Aims. Our primary aim was to assess reoperation-free survival at one year after the index injury in patients aged ≥ 75 years treated with internal fixation (IF) or
Tranexamic acid (TXA), an inhibitor of fibrinolysis,
reduces blood loss after total knee arthroplasty. However, its effect
on minimally invasive total hip arthroplasty (THA) is not clear.
We performed a prospective, randomised double-blind study to evaluate
the effect of two intravenous injections of TXA on blood loss in
patients undergoing minimally invasive THA. In total, 60 patients (35 women and 25 men with a mean age of
58.1 years; 17 to 84) who underwent unilateral minimally invasive
uncemented THA were randomly divided into the study group (30 patients,
20 women and ten men with a mean age of 56.5 years; 17 to 79) that
received two intravenous injections 1 g of TXA pre- and post-operatively
(TXA group), and a placebo group (30 patients, 15 women and 15 men
with a mean age of 59.5 years; 23 to 84). We compared the peri-operative
blood loss of the two groups. Actual blood loss was calculated from
the maximum reduction in the level of haemoglobin. All patients
were followed clinically for the presence of venous thromboembolism. The TXA group had a lower mean intra-operative blood loss of
441 ml (150 to 800) This prospective, randomised controlled study showed that a regimen
of two intravenous injections of 1 g TXA is effective for blood
conservation after minimally invasive THA. Cite this article:
Pseudotumour is a rare but important complication of metal-on-metal hip resurfacing that occurs much more commonly in women than in men. We examined the relationship between head-neck ratio (HNR) and pseudotumour formation in 18 resurfaced hips (18 patients) revised for pseudotumour and 42 asymptomatic control resurfaced hips (42 patients). Patients in whom pseudotumour formation had occurred had higher pre-operative HNR than the control patients (mean 1.37 ( We suggest that reducing the size of the femoral head, made possible by a high pre-operative HNR, increases the risk of impingement and edge loading, and may contribute to high wear and pseudotumour formation. As the incidence of pseudotumour is low in men, it appears safe to perform resurfacing in men. However, this study suggests that it is also reasonable to resurface in women with a pre-operative HNR ≤ 1.3.
To investigate the longevity of uncemented fixation of a femoral
component in total hip arthroplasty (THA) in patients with Dorr
type C proximal femoral morphology. A total of 350 consecutive uncemented THA in 320 patients were
performed between 1983 and 1987, by a single surgeon using the Taperloc
femoral component. The 63 patients (68 hips) with Dorr type C proximal
femoral morphology were the focus of this review. The mean age of
the patients was 69 years (24 to 88) and mean follow-up was 16.6
years (ten to 29). Survival analysis included eight patients (eight
hips) who died without undergoing revision surgery prior to obtaining
ten years follow-up. All 55 surviving patients (60 hips) were available
for clinical assessment and radiographic review. As a comparator
group, the survival and implant fixation in the remaining 282 THAs
(257 patients) with Dorr type A and B morphology were evaluated.
The mean age of these patients was 52 years (20 to 82).Aims
Patients and Methods
Between 1999 and 2005, 10 264 patients who had undergone total hip replacement (THR) for subcapital fracture of the hip were compared with 76 520 in whom THR had been performed for other reasons. All the cases were identified through the Swedish Hip Arthroplasty Register. The THRs performed as primary treatment for fracture were also compared with those done after failure of internal fixation. After seven years the rate of revision was higher in THR after fracture (4.4% vs 2.9%). Dislocation and periprosthetic fracture were the most common causes of revision. The risk was higher in men than in women. The type of femoral component and the surgical approach influenced the risk. After correction for gender, type of component and the surgical approach the revision rates were similar in the primary and secondary fracture THR groups. Total hip replacement is therefore a safe method for both the primary and secondary management of fracture of the hip.
We examined the relationships between the serum levels of chromium and cobalt ions and the inclination angle of the acetabular component and the level of activity in 214 patients implanted with a metal-on-metal resurfacing hip replacement. Each patient had a single resurfacing and no other metal in their body. All serum measurements were performed at a minimum of one year after operation. The inclination of the acetabular component was considered to be steep if the abduction angle was greater than 55°. There were significantly higher levels of metal ions in patients with steeply-inclined components (p = 0.002 for chromium, p = 0.003 for cobalt), but no correlation was found between the level of activity and the concentration of metal ions. A highly significant (p <
0.001) correlation with the arc of cover was found. Arcs of cover of less than 10 mm were correlated with a greater risk of high concentrations of serum metal ions. The arc of coverage was also related to the design of the component and to size as well as to the abduction angle of the acetabular component. Steeply-inclined acetabular components, with abduction angles greater than 55°, combined with a small size of component are likely to give rise to higher serum levels of cobalt and chromium ions. This is probably due to a greater risk of edge-loading.
We compared two methods of reconstruction of the abductor mechanism in 15 patients after prosthetic replacement of the upper femur, to assess abductor strength and function. Six patients in group I had direct fixation of the gluteus medius tendon and a segment of the original bone to the prosthesis. Nine patients in group 2 had the abductor tendon fixed to the iliotibial band. We assessed clinical function, isometric muscle strength and muscle cross-sectional area for each patient. The patients in group 1 had better clinical and functional results (p = 0.059), with average peak torques for hip abduction of 92% of that in the non-operated leg in group 1, and of 57% in group 2. Group 1 had a mean muscle cross-sectional area of 69% and a mean value of strength per cross-sectional area of 134% when compared with the control side. The respective values for group 2 were 52% and 91%. Direct fixation of the abductor muscles to the prostheses gave improved function and higher isometric abductor muscle force.
We have investigated the accuracy of placement of the femoral component using imageless navigation in 100 consecutive Birmingham Hip Resurfacings. Pre-operative templating determined the native neck-shaft angle and planned stem-shaft angle of the implant. The latter were verified post-operatively using digital anteroposterior unilateral radiographs of the hip. The mean neck-shaft angle determined before operation was 132.7° (118° to 160°). The mean planned stem-shaft angle was a relative valgus alignment of 9.7° ( Navigation in hip resurfacing may afford the surgeon a reliable and accurate method of placement of the femoral component.
The ideal bearing surface for young patients
undergoing total hip replacement (THR) remains controversial. We report
the five-year results of a randomised controlled trial comparing
the clinical and radiological outcomes of 102 THRs in 91 patients
who were <
65 years of age. These patients were randomised to
receive a cobalt–chrome on ultra-high-molecular-weight polyethylene,
cobalt–chrome on highly cross-linked polyethylene, or a ceramic-on-ceramic
bearing. In all, 97 hip replacements in 87 patients were available
for review at five years. Two hips had been revised, one for infection
and one for peri-prosthetic fracture. At the final follow-up there were no significant differences
between the groups for the mean Western Ontario and McMaster Universities
osteoarthritis index (pain, p = 0.543; function, p = 0.10; stiffness,
p = 0.99), Short Form-12 (physical component, p = 0.878; mental
component, p = 0.818) or Harris hip scores (p = 0.22). Radiological
outcomes revealed no significant wear in the ceramic group. Comparison of standard and highly cross-linked polyethylene,
however, revealed an almost threefold difference in the mean annual
linear wear rates (0.151 mm/year
We present a series of 114 patients with microbiologically-proven chronically-infected total hip replacement, treated between 1991 and 2004 by a two-stage exchange procedure with antibiotic-loaded cement, but without the use of a prolonged course of antibiotic therapy. The mean follow-up for all patients was 74 months (2 to 175) with all surviving patients having a minimum follow-up of two years. Infection was successfully eradicated in 100 patients (87.7%), a rate which is similar to that reported by others, but where prolonged adjuvant antibiotic therapy has been used. Using the technique described, a prolonged course of systemic antibiotics does not appear to be essential and the high cost of the administration of antibiotics can be avoided.
Aims. Periprosthetic joint infection (PJI) in total hip arthroplasty in the elderly may occur but has been subject to limited investigation. This study analyzed infection characteristics, surgical outcomes, and perioperative complications of octogenarians undergoing treatment for PJI in a single university-based institution. Methods. We identified 33 patients who underwent treatment for PJIs of the hip between January 2010 and December 2019 using our institutional joint registry. Mean age was 82 years (80 to 90), with 19 females (57%) and a mean BMI of 26 kg/m. 2. (17 to 41). Mean American Society of Anesthesiologists (ASA) grade was 3 (1 to 4) and mean Charlson Comorbidity Index was 6 (4 to 10). Leading pathogens included coagulase-negative Staphylococci (45%) and Enterococcus faecalis (9%). Two-stage exchange was performed in 30 joints and permanent resection
Aims. The Birmingham Hip Resurfacing (BHR)
Aims. Several different designs of hemiarthroplasty are used to treat intracapsular fractures of the proximal femur, with large variations in costs. No clinical benefit of modular over monoblock designs has been reported in the literature. Long-term data are lacking. The aim of this study was to report the ten-year implant survival of commonly used designs of hemiarthroplasty. Methods. Patients recorded by the Australian Orthopaedic Association National
Aims. The aim of this study was to examine the implant accuracy of custom-made partial pelvis
Aims. The proportion of
Aims. Computer-assisted 3D preoperative planning software has the potential to improve postoperative stability in total hip arthroplasty (THA). Commonly, preoperative protocols simulate two functional positions (standing and relaxed sitting) but do not consider other common positions that may increase postoperative impingement and possible dislocation. This study investigates the feasibility of simulating commonly encountered positions, and positions with an increased risk of impingement, to lower postoperative impingement risk in a CT-based 3D model. Methods. A robotic arm-assisted
Aims. It has been well documented in the