Restoration of leg length and offset is an important
goal in total hip replacement. This paper reports a calliper-based technique
to help achieve these goals by restoring the location of the centre
of the femoral head. This was validated first by using a co-ordinate
measuring machine to see how closely the calliper technique could
record and restore the centre of the femoral head when simulating
hip replacement on Sawbone femur, and secondly by using CT in patients
undergoing hip replacement. Results from the co-ordinate measuring machine showed that the
centre of the femoral head was predicted by the calliper to within
4.3 mm for offset (mean 1.6 (95% confidence interval (CI) 0.4 to
2.8)) and 2.4 mm for vertical height (mean -0.6 (95% CI -1.4 to
0.2)).
The CT scans showed that offset and vertical height were restored
to within 8 mm
(mean -1 (95% CI -2.1 to 0.6)) and -14 mm (mean 4 (95% CI 1.8 to
4.3)), respectively. Accurate assessment and restoration of the centre of the femoral
head is feasible with a calliper. It is quick, inexpensive, simple
to use and can be applied to any design of femoral component.
Aims. Refobacin Bone Cement R and Palacos R + G bone cement were introduced to replace the original cement Refobacin Palacos R in 2005. Both cements were assumed to behave in a biomechanically similar fashion to the original cement. The primary aim of this study was to compare the migration of a polished triple-tapered femoral stem fixed with either Refobacin Bone Cement R or Palacos R + G bone cement. Repeated radiostereometric analysis was used to measure migration of the
The aim of this study is to evaluate whether acetabular retroversion (AR) represents a structural anatomical abnormality of the pelvis or is a functional phenomenon of pelvic positioning in the sagittal plane, and to what extent the changes that result from patient-specific functional position affect the extent of AR. A comparative radiological study of 19 patients (38 hips) with AR were compared with a control group of 30 asymptomatic patients (60 hips). CT scans were corrected for rotation in the axial and coronal planes, and the sagittal plane was then aligned to the anterior pelvic plane. External rotation of the hemipelvis was assessed using the superior iliac wing and inferior iliac wing angles as well as quadrilateral plate angles, and correlated with cranial and central acetabular version. Sagittal anatomical parameters were also measured and correlated to version measurements. In 12 AR patients (24 hips), the axial measurements were repeated after matching sagittal pelvic rotation with standing and supine anteroposterior radiographs.Aims
Methods
Pelvic incidence (PI) is considered an important anatomical parameter for determining the sagittal balance of the spine. The contribution of an abnormal PI to hip osteoarthritis (OA) remains controversial. In this study, we aimed to investigate the relationship between PI and hip OA, and the difference in PI between hip OA without anatomical abnormalities (primary OA) and hip OA with developmental dysplasia of the hip (DDH-OA). In this study, 100 patients each of primary OA, DDH-OA, and control subjects with no history of hip disease were included. CT images were used to measure PI, sagittal femoral head coverage, α angle, and acetabular anteversion. PI was also subdivided into three categories: high PI (larger than 64.0°), medium PI (42.0° to 64.0°), and low PI (less than 42.0°). The anterior centre edge angles, posterior centre edge angles, and total sagittal femoral head coverage were measured. The correlations between PI and sagittal femoral head coverage, α angle, and acetabular anteversion were examined.Aims
Methods
We aimed to evaluate the long-term outcome of highly cross-linked polyethylene (HXLPE) cemented acetabular components and assess whether any radiolucent lines (RLLs) which arose were progressive. We retrospectively reviewed 170 patients who underwent 187 total hip arthroplasties at two hospitals with a minimum follow-up of ten years. All interventions were performed using the same combination of HXLPE cemented acetabular components with femoral stems made of titanium alloy. Kaplan-Meier survival analysis was performed for the primary endpoint of acetabular component revision surgery for any reason and secondary endpoint of the appearance of RLLs. RLLs that had appeared once were observed over time. We statistically assessed potential relationships between RLLs and a number of factors, including the technique of femoral head autografting and the Japanese Orthopaedic Association score.Aims
Methods
Hip displacement, common in patients with cerebral palsy (CP), causes pain and hinders adequate care. Hip reconstructive surgery (HRS) is performed to treat hip displacement; however, only a few studies have quantitatively assessed femoral head sphericity after HRS. The aim of this study was to quantitatively assess improvement in hip sphericity after HRS in patients with CP. We retrospectively analyzed hip radiographs of patients who had undergone HRS because of CP-associated hip displacement. The pre- and postoperative migration percentage (MP), femoral neck-shaft angle (NSA), and sphericity, as determined by the Mose hip ratio (MHR), age at surgery, Gross Motor Function Classification System level, surgical history including Dega pelvic osteotomy, and triradiate cartilage status were studied. Regression analyses using linear mixed model were performed to identify factors affecting hip sphericity improvement.Aims
Methods
The complex relationship between acetabular component position and spinopelvic mobility in patients following total hip arthroplasty (THA) renders it difficult to optimize acetabular component positioning. Mobility of the normal lumbar spine during postural changes results in alterations in pelvic tilt (PT) to maintain the sagittal balance in each posture and, as a consequence, markedly changes the functional component anteversion (FCA). This study aimed to investigate the in vivo association of lumbar degenerative disc disease (DDD) with the PT angle and with FCA during postural changes in THA patients. A total of 50 patients with unilateral THA underwent CT imaging for radiological evaluation of presence and severity of lumbar DDD. In all, 18 patients with lumbar DDD were compared to 32 patients without lumbar DDD. In vivo PT and FCA, and the magnitudes of changes (ΔPT; ΔFCA) during supine, standing, swing-phase, and stance-phase positions were measured using a validated dual fluoroscopic imaging system.Aims
Methods
The prevalence of combined abnormalities of femoral torsion (FT) and tibial torsion (TT) is unknown in patients with femoroacetabular impingement (FAI) and hip dysplasia. This study aimed to determine the prevalence of combined abnormalities of FT and TT, and which subgroups are associated with combined abnormalities of FT and TT. We retrospectively evaluated symptomatic patients with FAI or hip dysplasia with CT scans performed between September 2011 and September 2016. A total of 261 hips (174 patients) had a measurement of FT and TT. Their mean age was 31 years (SD 9), and 63% were female (165 hips). Patients were compared to an asymptomatic control group (48 hips, 27 patients) who had CT scans including femur and tibia available for analysis, which had been acquired for nonorthopaedic reasons. Comparisons were conducted using analysis of variance with Bonferroni correction.Aims
Methods
The diagnosis of developmental dysplasia of the hip (DDH) is challenging owing to extensive variation in paediatric pelvic anatomy. Artificial intelligence (AI) may represent an effective diagnostic tool for DDH. Here, we aimed to develop an anteroposterior pelvic radiograph deep learning system for diagnosing DDH in children and analyze the feasibility of its application. In total, 10,219 anteroposterior pelvic radiographs were retrospectively collected from April 2014 to December 2018. Clinicians labelled each radiograph using a uniform standard method. Radiographs were grouped according to age and into ‘dislocation’ (dislocation and subluxation) and ‘non-dislocation’ (normal cases and those with dysplasia of the acetabulum) groups based on clinical diagnosis. The deep learning system was trained and optimized using 9,081 radiographs; 1,138 test radiographs were then used to compare the diagnoses made by deep learning system and clinicians. The accuracy of the deep learning system was determined using a receiver operating characteristic curve, and the consistency of acetabular index measurements was evaluated using Bland-Altman plots.Aims
Methods
Abnormal femoral torsion (FT) is increasingly recognized as an additional cause for femoroacetabular impingement (FAI). It is unknown if in-toeing of the foot is a specific diagnostic sign for increased FT in patients with symptomatic FAI. The aims of this study were to determine: 1) the prevalence and diagnostic accuracy of in-toeing to detect increased FT; 2) if foot progression angle (FPA) and tibial torsion (TT) are different among patients with abnormal FT; and 3) if FPA correlates with FT. A retrospective, institutional review board (IRB)-approved, controlled study of 85 symptomatic patients (148 hips) with FAI or hip dysplasia was performed in the gait laboratory. All patients had a measurement of FT (pelvic CT scan), TT (CT scan), and FPA (optical motion capture system). We allocated all patients to three groups with decreased FT (< 10°, 37 hips), increased FT (> 25°, 61 hips), and normal FT (10° to 25°, 50 hips). Cluster analysis was performed.Aims
Patients and Methods
In patients where the proximal femur shows gross deformity due
to degenerative changes or fracture, the contralateral femur is
often used to perform preoperative templating for hip arthroplasty.
However, femurs may not be symmetrical: the aim of this study was
to determine the degree of variation between hips in healthy individuals and
to determine whether it is affected by demographic parameters. CT-scan based modelling was used to examine the pelvis and bilateral
femurs of 345 patients (211 males, 134 women; mean age 62 years
(standard deviation (Aims
Materials and Methods
This study sought to establish the prevalence of the cross over
sign (COS) and posterior wall sign (PWS) in relation to the anterior
pelvic plane (APP) in an asymptomatic population through reliable
and accurate 3D-CT based assessment. Data from pelvic CT scans of 100 asymptomatic subjects (200 hips)
undertaken for conditions unrelated to disorders of the hip were
available for analysis in this study. A previously established 3D
analysis method was applied to assess the prevalence of the COS
and PWS in relation to the APP.Aims
Materials and Methods
To determine the effect of a change in design of a cementless
ceramic acetabular component in fixation and clinical outcome after
total hip arthroplasty We compared 342 hips (302 patients) operated between 1999 and
2005 with a relatively smooth hydroxyapatite coated acetabular component
(group 1), and 337 hips (310 patients) operated between 2006 and
2011 using a similar acetabular component with a macrotexture on
the entire outer surface of the component (group 2). The mean age of
the patients was 53.5 (14 to 70) in group 1 and 53.0 (15 to 70)
in group 2. The mean follow-up was 12.7 years (10 to 17) for group
1 and 7.2 years (4 to 10) for group 2.Aims
Patients and Methods
To present a surgically relevant update of trunnionosis. Systematic review performed April 2017.Aims
Materials and Methods
The primary aim of this study was to define and quantify three
new measurements to indicate the position of the greater trochanter.
Secondary aims were to define ‘functional antetorsion’ as it relates
to abductor function in populations both with and without torsional
abnormality. Three new measurements, functional antetorsion, posterior tilt,
and posterior translation of the greater trochanter, were assessed
from 61 CT scans of cadaveric femurs, and their reliability determined.
These measurements and their relationships were also evaluated in
three groups of patients: a control group (n = 22), a ‘high-antetorsion’ group
(n = 22) and a ‘low-antetorsion’ group (n = 10).Aims
Patients and Methods
To evaluate the outcomes of cemented total hip arthroplasty (THA)
following a fracture of the acetabulum, with evaluation of risk
factors and comparison with a patient group with no history of fracture. Between 1992 and 2016, 49 patients (33 male) with mean age of
57 years (25 to 87) underwent cemented THA at a mean of 6.5 years
(0.1 to 25) following acetabular fracture. A total of 38 had undergone
surgical fixation and 11 had been treated non-operatively; 13 patients
died at a mean of 10.2 years after THA (0.6 to 19). Patients were
assessed pre-operatively, at one year and at final follow-up (mean
9.1 years, 0.5 to 23) using the Oxford Hip Score (OHS). Implant
survivorship was assessed. An age and gender-matched cohort of THAs
performed for non-traumatic osteoarthritis (OA) or avascular necrosis
(AVN) (n = 98) were used to compare complications and patient-reported outcome
measures (PROMs).Aims
Patients and Methods
To confirm whether developmental dysplasia of
the hip has a risk of hip impingement, we analysed maximum ranges
of movement to the point of bony impingement, and impingement location
using three-dimensional (3D) surface models of the pelvis and femur
in combination with 3D morphology of the hip joint using computer-assisted methods.
Results of computed tomography were examined for 52 hip joints with
DDH and 73 normal healthy hip joints. DDH shows larger maximum extension
(p = 0.001) and internal rotation at 90° flexion (p <
0.001).
Similar maximum flexion (p = 0.835) and external rotation (p = 0.713)
were observed between groups, while high rates of extra-articular
impingement were noticed in these directions in DDH (p <
0.001).
Smaller cranial acetabular anteversion (p = 0.048), centre-edge
angles (p <
0.001), a circumferentially shallower acetabulum,
larger femoral neck anteversion (p <
0.001), and larger alpha
angle were identified in DDH. Risk of anterior impingement in retroverted
DDH hips is similar to that in retroverted normal hips in excessive
adduction but minimal in less adduction. These findings might be
borne in mind when considering the possibility of extra-articular
posterior impingement in DDH being a source of pain, particularly
for patients with a highly anteverted femoral neck. Cite this article:
Tibiofemoral alignment is important to determine the rate of
progression of osteoarthritis and implant survival after total knee
arthroplasty (TKA). Normally, surgeons aim for neutral tibiofemoral
alignment following TKA, but this has been questioned in recent
years. The aim of this study was to evaluate whether varus or valgus
alignment indeed leads to increased medial or lateral tibiofemoral
forces during static and dynamic weight-bearing activities. Tibiofemoral contact forces and moments were measured in nine
patients with instrumented knee implants. Medial force ratios were
analysed during nine daily activities, including activities with
single-limb support (e.g. walking) and double-limb support (e.g.
knee bend). Hip-knee-ankle angles in the frontal plane were analysed
using full-leg coronal radiographs. Aims
Patients and Methods
In developmental dysplasia of the hip (DDH),
a bone defect is often observed superior to the acetabulum after
the reconstruction at the level of the true acetabulum during total
hip replacement (THR). However, the essential amount of uncemented
acetabular component coverage required for a satisfactory outcome
remains controversial. The purpose of this study was to assess the
stability and function of acetabular components with a lack of coverage >
30% (31% to 50%). A total of 760 DDH patients underwent THR with
acetabular reconstruction at the level of the true floor. Lack of
coverage above the acetabular component of >
30% occurred in 56
patients. Intra-operatively, autogenous morcellised bone grafts
were used to fill the uncovered portion. Other than two screws inserted through
the acetabular shell, no additional structural supports were used
in these hips. In all, four patients were lost to follow-up. Therefore,
52 patients (52 hips, 41 women and 11 men) with a mean age of 60.1
years (42 to 78) were available for this study at a mean of 4.8
years (3 to 7). There were no instances of prosthesis revision or
marked loosening during the follow-up. The Harris hip score improved
from a mean of 40.7 points ( Cite this article:
