The aim of this study was to investigate the
relationship between the geometry of the proximal femur and the incidence
of intra-operative fracture during uncemented total hip arthroplasty
(THA). We studied the pre-operative CT scans of 100 patients undergoing
THA with an uncemented femoral component. We measured the anteroposterior
and mediolateral dimensions at the level of division of the femoral
neck to calculate the aspect ratio of the femur. Wide variations
in the shape of the femur were observed, from round, to very narrow
elliptic. The femurs of women were narrower than those of men (p
<
0.0001) and small femurs were also narrower than large ones.
Patients with an intra-operative fracture of the calcar had smaller
and narrower femurs than those without a fracture (p <
0.05)
and the implanted Corail stems were smaller in those with a fracture
(mean size 9 The variability of the shape of the femoral neck at the level
of division contributes to the understanding of the causation of
intra-operative fractures in uncemented THA. Cite this article:
Our understanding of the origin of hip pain in
degenerative disorders of the hip, including primary osteoarthritis, avascular
necrosis and femoroacetabular impingement (FAI), is limited. We
undertook a histological investigation of the nociceptive innervation
of the acetabular labrum, ligamentum teres and capsule of the hip,
in order to prove pain- and proprioceptive-associated marker expression.
These structures were isolated from 57 patients who had undergone
elective hip surgery (44 labral samples, 33 ligamentum teres specimens,
34 capsular samples; in 19 patients all three structures were harvested).
A total of
15 000 histological sections were prepared that were investigated
immunohistochemically for the presence of protein S-100, 68 kDa
neurofilament, neuropeptide Y, nociceptin and substance P. The tissues
were evaluated in six representative areas. Within the labrum, pain-associated free nerve ending expression
was located predominantly at its base, decreasing in the periphery.
In contrast, the distribution within the ligamentum teres showed
a high local concentration in the centre. The hip capsule had an
almost homogeneous marker expression in all investigated areas. This study showed characteristic distribution profiles of nociceptive
and pain-related nerve fibres, which may help in understanding the
origin of hip pain. Cite this article:
We have updated our previous randomised controlled trial comparing release of chromium (Cr) and cobalt (Co) ions and included levels of titanium (Ti) ions. We have compared the findings from 28 mm metal-on-metal total hip replacement, performed using titanium CLS/Spotorno femoral components and titanium AlloFit acetabular components with Metasul bearings, with Durom hip resurfacing using a Metasul articulation or bearing and a titanium plasma-sprayed coating for fixation of the acetabular component. Although significantly higher blood ion levels of Cr and Co were observed at three months in the resurfaced group than in total hip replacement, no significant difference was found at two years post-operatively for Cr, 1.58 μg/L and 1.62 μg/L respectively (p = 0.819) and for Co, 0.67 μg/L and 0.94 μg/L respectively (p = 0.207). A steady state was reached at one year in the resurfaced group and after three months in the total hip replacement group. Interestingly, Ti, which is not part of the bearing surfaces with its release resulting from metal corrosion, had significantly elevated ion levels after implantation in both groups. The hip resurfacing group had significantly higher Ti levels than the total hip replacement group for all periods of follow-up. At two years the mean blood levels of Ti ions were 1.87 μg/L in hip resurfacing and and 1.30 μg/L in total hip replacement (p = 0.001). The study confirms even with different bearing diameters and clearances, hip replacement and 28 mm metal-on-metal total hip replacement produced similar Cr and Co metal ion levels in this randomised controlled trial study design, but apart from wear on bearing surfaces, passive corrosion of exposed metallic surfaces is a factor which influences ion concentrations. Ti plasma spray coating the acetabular components for hip resurfacing produces significantly higher release of Ti than Ti grit-blasted surfaces in total hip replacement.
We compared the accuracy of the growth remaining
method of assessing leg-length discrepancy (LLD) with the straight-line
graph method, the multiplier method and their variants. We retrospectively
reviewed the records of 44 patients treated by percutaneous epiphysiodesis
for LLD. All were followed up until maturity. We used the modified Green–Anderson
growth-remaining method (Method 1) to plan the timing of epiphysiodesis.
Then we presumed that the other four methods described below were
used pre-operatively for calculating the timing of epiphysiodesis. We
then assumed that these four methods were used pre-operatively.
Method 2 was the original Green–Anderson growth-remaining method;
Method 3, Paley’s multiplier method using bone age; Method 4, Paley’s
multiplier method using chronological age; and Method 5, Moseley’s
straight-line graph method. We compared ‘Expected LLD at maturity
with surgery’ with ‘Final LLD at maturity with surgery’ for each
method. Statistical analysis revealed that ‘Expected LLD at maturity
with surgery’ was significantly different from ‘Final LLD at maturity
with surgery’. Method 2 was the most accurate. There was a significant
correlation between ‘Expected LLD at maturity with surgery’ and
‘Final LLD at maturity with surgery’, the greatest correlation being
with Method 2. Generally all the methods generated an overcorrected
value. No method generates the precise ‘Expected LLD at maturity
with surgery’. It is essential that an analysis of the pattern of
growth is taken into account when predicting final LLD. As many
additional data as possible are required. Cite this article:
We have developed an illustrated questionnaire, the Hand20, comprising 20 short and easy-to-understand questions to assess disorders of the upper limb. We have examined the usefulness of this questionnaire by comparing reliability, validity, responsiveness and the level of missing data with those of the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire. A series of 431 patients with disorders of the upper limb completed the Hand20 and the Japanese version of the DASH (DASH-JSSH) questionnaire. The norms for Hand20 scores were determined in another cross-sectional study. Most patients had no difficulty in completing the Hand20 questionnaire, whereas the DASH-JSSH had a significantly higher rate of missing data. The standard score for the Hand20 was smaller than the reported norms for the DASH. Our study showed that the Hand20 questionnaire provided validation comparable with that of the DASH-JSSH. Explanatory illustrations and short questions which were easy-to-understand led to better rates of response and fewer missing data, even in elderly individuals with cognitive deterioration.
We evaluated 30 patients with cervical myelopathy before and after decompressive surgery and compared them with 42 healthy controls. All were asked to grip and release their fingers as rapidly as possible for 15 seconds. Films recorded with a digital camera were divided into three files of five seconds each. Three doctors independently counted the number of grip and release cycles in a blinded manner (N1 represents the number of cycles for the first five-second segment, N2 for the second and N3 for the third). N2 and N3 of the pre-operative group were significantly fewer than those of the control group, and the postoperative group’s results were significantly greater than those of the pre-operative group. In the control group, the numbers decreased significantly with each succeeding five-second interval (fatigue phenomenon). In the pre-operative myelopathy group there was no significant difference between N1 and N2 (freezing phenomenon). The 15-second test is shown to be reliable in the quantitative evaluation of cervical myelopathy. Although it requires a camera and animation files, it can detect small changes in neurological status because of its precise and objective nature.
In In a hip fracture experiment, nine pairs of human cadaver femurs
were tested in a paired study design. The femurs were then re-matched
according to BMD, creating two new test groups. Intra-pair variance
and paired correlations in fixation stability were calculated. A
hypothetical power analysis was then performed to explore the required sample
size for the two types of group allocation. Objective
Methods
Our aim was to determine the most repeatable three-dimensional measurement of glenoid orientation and to compare it between shoulders with intact and torn rotator cuffs. Our null hypothesis was that glenoid orientation in the scapulae of shoulders with a full-thickness tear of the rotator cuff was the same as that in shoulders with an intact rotator cuff. We studied 24 shoulders in cadavers, 12 with an intact rotator cuff and 12 with a full-thickness tear. Two different observers used a three-dimensional digitising system to measure glenoid orientation in the scapular plane (ie glenoid inclination) using six different techniques. Glenoid version was also measured. The overall precision of the measurements revealed an error of less than 0.6°. Intraobserver reliability (correlation coefficients of 0.990 and 0.984 for each observer) and interobserver reliability (correlation coefficient of 0.985) were highest for measurement of glenoid inclination based on the angle obtained from a line connecting the superior and inferior points of the glenoid and that connecting the most superior point of the glenoid and the most superior point on the body of the scapula. There were no differences in glenoid inclination (p = 0.34) or glenoid version (p = 0.12) in scapulae from shoulders with an intact rotator cuff and those with a full-thickness tear. Abnormal glenoid orientation was not present in shoulders with a torn rotator cuff.
The aim of our study was to investigate whether placing of the femoral component of a hip resurfacing in valgus protected against spontaneous fracture of the femoral neck. We performed a hip resurfacing in 20 pairs of embalmed femora. The femoral component was implanted at the natural neck-shaft angle in the left femur and with a 10° valgus angle on the right. The bone mineral density of each femur was measured and CT was performed. Each femur was evaluated in a materials testing machine using increasing cyclical loads. In specimens with good bone quality, the 10° valgus placement of the femoral component had a protective effect against fractures of the femoral neck. An adverse effect was detected in osteoporotic specimens. When resurfacing the hip a valgus position of the femoral component should be achieved in order to prevent fracture of the femoral neck. Patient selection remains absolutely imperative. In borderline cases, measurement of bone mineral density may be indicated.
Progressive degenerative changes in the medial
compartment of the knee following lateral unicompartmental arthroplasty
(UKA) remains a leading indication for revision surgery. The purpose
of this study is to evaluate changes in the congruence and joint
space width (JSW) of the medial compartment following lateral UKA.
The congruence of the medial compartment of 53 knees (24 men, 23
women, mean age 13.1 years; Our data suggest that a well conducted lateral UKA may improve
the congruence and normalise the JSW of the medial compartment,
potentially preventing progression of degenerative change. Cite this article:
An increased tibial tubercle–trochlear groove
(TT-TG) distance is related to patellar maltracking and instability.
Tibial tubercle transfer is a common treatment option for these
patients with good short-term results, although the results can
deteriorate over time owing to the progression of osteoarthritis.
We present a ten-year follow-up study of a self-centring tibial
tubercle osteotomy in 60 knees, 30 with maltracking and 30 with
patellar instability. Inclusion criteria were a TT-TG ≥ 15 mm and
symptoms for >
one year. One patient (one knee) was lost to follow-up
and one required total knee arthroplasty because of progressive
osteoarthritis. Further patellar dislocations occurred in three
knees, all in the instability group, one of which required further
surgery. The mean visual analogue scores for pain, and Lysholm and
Kujala scores improved significantly and were maintained at the
final follow-up (repeated measures, p = 0.000, intergroup differences
p = 0.449). Signs of maltracking were found in only a minority of
patients, with no difference between groups (p >
0.05). An increase
in patellofemoral osteoarthritis was seen in 16 knees (31%) with
a maximum of grade 2 on the Kellgren–Lawrence scale. The mean increase
in grades was 0.31 (0 to 2) and 0.41 (0 to 2) in the maltracking
and instability groups respectively (p = 0.2285) This self-centring tibial tubercle osteotomy provides good results
at ten years’ follow-up without inducing progressive osteoarthritis. Cite this article:
Cadaveric models of the shoulder evaluate discrete motion segments
using the glenohumeral joint in isolation over a defined trajectory.
The aim of this study was to design, manufacture and validate a
robotic system to accurately create three-dimensional movement of
the upper body and capture it using high-speed motion cameras. In particular, we intended to use the robotic system to simulate
the normal throwing motion in an intact cadaver. The robotic system
consists of a lower frame (to move the torso) and an upper frame
(to move an arm) using seven actuators. The actuators accurately
reproduced planned trajectories. The marker setup used for motion
capture was able to determine the six degrees of freedom of all
involved joints during the planned motion of the end effector.Objectives
Methods
We investigated the incidence and risk factors
for the development of avascular necrosis (AVN) of the femoral head in
the course of treatment of children with cerebral palsy (CP) and
dislocation of the hip. All underwent open reduction, proximal femoral
and Dega pelvic osteotomy. The inclusion criteria were: a predominantly
spastic form of CP, dislocation of the hip (migration percentage,
MP >
80%), Gross Motor Function Classification System, (GMFCS) grade
IV to V, a primary surgical procedure and follow-up of >
one year. There were 81 consecutive children (40 girls and 41 boys) in
the study. Their mean age was nine years (3.5 to 13.8) and mean
follow-up was 5.5 years (1.6 to 15.1). Radiological evaluation included
measurement of the MP, the acetabular index (AI), the epiphyseal
shaft angle (ESA) and the pelvic femoral angle (PFA). The presence
and grade of AVN were assessed radiologically according to the Kruczynski
classification. Signs of AVN (grades I to V) were seen in 79 hips (68.7%). A
total of 23 hips (18%) were classified between grades III and V. Although open reduction of the hip combined with femoral and
Dega osteotomy is an effective form of treatment for children with
CP and dislocation of the hip, there were signs of avascular necrosis
in about two-thirds of the children. There was a strong correlation
between post-operative pain and the severity of the grade of AVN. Cite this article:
We analysed data from the Oxford hip and knee questionnaires collected by the New Zealand Joint Registry at six months and five years after joint replacement, to determine if there was any relationship between the scores and the risk of early revision. Logistic regression of the six-month scores indicated that for every one-unit decrease in the Oxford score, the risk of revision within two years increased by 9.7% for total hip replacement (THR), 9.9% for total knee replacement (TKR) and 12.0% for unicompartmental knee replacement (UKR). Our findings showed that 70% of the revisions within two years for TKR and 67% for THR and UKR would have been captured by monitoring the lowest 22%, 28% and 28%, respectively, of the Oxford scores. When analysed using the Kalairajah classification a score of <
27 (poor) was associated with a risk of revision within two years of 7.6% for THR, 7.0% for TKR and 24.3% for UKR, compared with risks of 0.7%, 0.7% and 1.8%, respectively, for scores >
34 (good or excellent). Our study confirms that the Oxford hip and knee scores at six months are useful predictors of early revision after THR and TKR and we recommend their use for the monitoring of the outcome and potential failure in these patients.
We studied 33 third generation, alumina ceramic-on-ceramic bearings retrieved from cementless total hip replacements after more than six months in situ. Wear volume was measured with a Roundtest machine, and acetabular orientation from the anteroposterior pelvic radiograph. The overall median early wear rate was 0.1 mm3/yr for the femoral heads, and 0.04 mm3/yr for the acetabular liners. We then excluded hips where the components had migrated. In this stable subgroup of 22 bearings, those with an acetabular anteversion of <
15° (seven femoral heads) had a median femoral head wear rate of 1.2 mm3/yr, compared with 0 mm3/yr for those with an anteversion of ≥15° (15 femoral heads, p <
0.001). Even under edge loading, wear volumes with ceramic-on-ceramic bearings are small in comparison to other bearing materials. Low acetabular anteversion is associated with greater wear.
We have studied the effect of shortening of the femoral neck and varus collapse on the functional capacity and quality of life of patients who had undergone fixation of an isolated intracapsular fracture of the hip with cancellous screws. After screening 660 patients at four university medical centres, 70 patients with a mean age of 71 years (20 to 90) met the inclusion criteria. Overall, 66% (46 of 70) of the fractures healed with >
5 mm of shortening and 39% (27 of 70) with >
5° of varus. Patients with severe shortening of the femoral neck had significantly lower short form-36 questionnaire (SF-36) physical functioning scores (no/mild (<
5 mm) vs severe shortening (>
10 mm); 74 vs 42 points, p <
0.001). A similar effect was noted with moderate shortening, suggesting a gradient effect (no/mild (<
5 mm) vs moderate shortening (5 to 10 mm); 74 vs 53 points, p = 0.011). Varus collapse correlated moderately with the occurrence of shortening (r = 0.66, p <
0.001). Shortening also resulted in a significantly lower EuroQol questionnaire (EQ5D) index scores (p = 0.05). In a regression analysis shortening of the femoral neck was the only significant variable predictive of a low SF-36 physical functioning score (p <
0.001).
The August 2014 Research Roundup360 looks at: Antibiotic loaded ceramic of use in osteomyelitis; fibronectin implicated in cartilage degeneration; Zinc Chloride accelerates fracture healing in rats; advertisements and false claims; Net Promoter Score: substance or rhetoric?; aspirin for venous thromboembolism prophylaxis and dissection, stress and the soul.
We compared lower limb coronal alignment measurements
obtained pre- and post-operatively with long-leg radiographs and
computer navigation in patients undergoing primary total knee replacement
(TKR). A series of 185 patients had their pre- and post-implant
radiological and computer-navigation system measurements of coronal alignment
compared using the Bland-Altman method. The study included 81 men
and 104 women with a mean age of 68.5 years (32 to 87) and a mean
body mass index of 31.7 kg/m2 (19 to 49). Pre-implant
Bland–Altman limits of agreement were -9.4° to 8.6° with a repeatability
coefficient of 9.0°. The Bland–Altman plot showed a tendency for the
radiological measurement to indicate a higher level of pre-operative
deformity than the corresponding navigation measurement. Post-implant
limits of agreement were -5.0° to 5.4° with a repeatability coefficient
of 5.2°. The tendency for valgus knees to have greater deformity
on the radiograph was still seen, but was weaker for varus knees. The alignment seen or measured intra-operatively during TKR is
not necessarily the same as the deformity seen on a standing long-leg
radiograph either pre- or post-operatively. Further investigation
into the effect of weight-bearing and surgical exposure of the joint
on the mechanical femorotibial angle is required to enable the most appropriate
intra-operative alignment to be selected.
To evaluate the neck strength of school-aged rugby players, and
to define the relationship with proxy physical measures with a view
to predicting neck strength. Cross-sectional cohort study involving 382 rugby playing schoolchildren
at three Scottish schools (all male, aged between 12 and 18 years).
Outcome measures included maximal isometric neck extension, weight,
height, grip strength, cervical range of movement and neck circumference.Objectives
Methods
The β-angle is a radiological tool for measuring the distance between the pathological head-neck junction and the acetabular rim with the hip in 90° of flexion in patients with femoroacetabular impingement. Initially it was measured using an open-chamber MRI. We have developed a technique to measure this angle on plain radiographs. Correlation analysis was undertaken to determine the relationship between the range of movement and the β-angle in 50 patients with femoroacetabular impingement and 50 asymptomatic control subjects. Inter- and intra-observer reliability of the β-angle was also evaluated. Patients with femoroacetabular impingement had a significantly smaller (p <
0.001) mean β-angle (15.6°, 95% confidence interval (CI) 13.3 to 17.7) compared with the asymptomatic group (38.7°, 95% CI 36.5 to 41.0). Correlation between internal rotation and the β-angle was high in the impingement group and moderate in the asymptomatic group. The β-angle had excellent inter- and intra-observer reliability in both groups. Our findings suggest that the measurement of the β-angle on plain radiography may represent a valid, reproducible and cost-effective alternative to open MRI in the assessment of the pathological bony anatomy in patients with cam, pincer and mixed femoroacetabular impingement.