Recent events have highlighted the importance
of implant design for survival and wear-related complications following
metal-on-metal hip resurfacing arthroplasty. The mid-term survival
of the most widely used implant, the Birmingham Hip Resurfacing
(BHR), has been described by its designers. The aim of this study
was to report the ten-year survival and patient-reported functional
outcome of the BHR from an independent centre. In this cohort of 554 patients (646 BHRs) with a mean age of
51.9 years (16.5 to 81.5) followed for a mean of eight years (1
to 12), the survival and patient-reported functional outcome depended
on gender and the size of the implant. In female hips (n = 267)
the ten-year survival was 74% (95% confidence interval (CI) 83 to
91), the ten-year revision rate for pseudotumour was 7%, the mean
Oxford hip score (OHS) was 43 ( This study supports the ongoing use of resurfacing in young active
men, who are a subgroup of patients who tend to have problems with
conventional THR. In contrast, the results in women have been poor
and we do not recommend metal-on-metal resurfacing in women. Continuous
follow-up is recommended because of the increasing incidence of
pseudotumour with the passage of time.
We reviewed the outcome of a retrospective case series of eight patients with atlantoaxial instability who had been treated by percutaneous anterior transarticular screw fixation and grafting under image-intensifier guidance between December 2005 and June 2008. The mean follow-up was 19 months (8 to 27). All eight patients had a solid C1–2 fusion. There were no breakages or displacement of screws. All the patients with pre-operative neck pain had immediate relief from their symptoms or considerable improvement. There were no major complications. Our preliminary clinical results suggest that percutaneous anterior transarticulation screw fixation is technically feasible, safe, useful and minimally invasive when using the appropriate instruments allied to intra-operative image intensification, and by selecting the correct puncture point, angle and depth of insertion.
Giant cell tumours (GCT) of the synovium and
tendon sheath can be classified into two forms: localised (giant
cell tumour of the tendon sheath, or nodular tenosynovitis) and
diffuse (diffuse-type giant cell tumour or pigmented villonodular
synovitis). The former principally affects the small joints. It
presents as a solitary slow-growing tumour with a characteristic
appearance on MRI and is treated by surgical excision. There is
a significant risk of multiple recurrences with aggressive diffuse
disease. A multidisciplinary approach with dedicated MRI, histological assessment
and planned surgery with either adjuvant radiotherapy or systemic
targeted therapy is required to improve outcomes in recurrent and
refractory diffuse-type GCT. Although arthroscopic synovectomy through several portals has
been advocated as an alternative to arthrotomy, there is a significant
risk of inadequate excision and recurrence, particularly in the
posterior compartment of the knee. For local disease partial arthroscopic
synovectomy may be sufficient, at the risk of recurrence. For both
local and diffuse intra-articular disease open surgery is advised
for recurrent disease. Marginal excision with focal disease will
suffice, not dissimilar to the treatment of GCT of tendon sheath.
For recurrent and extra-articular soft-tissue disease adjuvant therapy,
including intra-articular radioactive colloid or moderate-dose external
beam radiotherapy, should be considered.
We have reviewed the rate of revision of fully cemented, hybrid and uncemented primary total hip replacements (THRs) registered in the New Zealand Joint Registry between 1999 and December 2006 to determine whether there was any statistically significant difference in the early survival and reason for revision in these different types of fixation. The percentage rate of revision was calculated per 100 component years and compared with the reason for revision, the type of fixation and the age of the patients. Of the 42 665 primary THRs registered, 920 (2.16%) underwent revision requiring change of at least one component. Fully-cemented THRs had a lower rate of revision when considering all causes for failure (p <
0.001), but below the age of 65 years uncemented THRs had a lower rate (p <
0.01). The rate of revision of the acetabular component for aseptic loosening was less in the uncemented and hybrid groups compared with that in the fully cemented group (p <
0.001), and the rate of revision of cemented and uncemented femoral components was similar, except in patients over 75 years of age in whom revision of cemented femoral components was significantly less frequent (p <
0.02). Revision for infection was more common in patients aged below 65 years and in cemented and hybrid THRs compared with cementless THRs (p <
0.001). Dislocation was the most common cause of revision for all types of fixation and was more frequent in both uncemented acetabular groups (p <
0.001). The experience of the surgeon did not affect the findings. Although cemented THR had the lowest rate of revision for all causes in the short term (90 days), uncemented THR had the lowest rate of aseptic loosening in patients under 65 years of age and had rates comparable with international rates of aseptic loosening in those over 65 years.
It is accepted that resurfacing hip replacement
preserves the bone mineral density (BMD) of the femur better than total
hip replacement (THR). However, no studies have investigated any
possible difference on the acetabular side. Between April 2007 and March 2009, 39 patients were randomised
into two groups to receive either a resurfacing or a THR and were
followed for two years. One patient’s resurfacing subsequently failed,
leaving 19 patients in each group. Resurfaced replacements maintained proximal femoral BMD and,
compared with THR, had an increased bone mineral density in Gruen
zones 2, 3, 6, and particularly zone 7, with a gain of 7.5% (95%
confidence interval (CI) 2.6 to 12.5) compared with a loss of 14.6%
(95% CI 7.6 to 21.6). Resurfacing replacements maintained the BMD
of the medial femoral neck and increased that in the lateral zones
between 12.8% (95% CI 4.3 to 21.4) and 25.9% (95% CI 7.1 to 44.6). On the acetabular side, BMD was similar in every zone at each
point in time. The mean BMD of all acetabular regions in the resurfaced
group was reduced to 96.2% (95% CI 93.7 to 98.6) and for the total
hip replacement group to 97.6% (95% CI 93.7 to 101.5) (p = 0.4863).
A mean total loss of 3.7% (95% CI 1.0 to 6.5) and 4.9% (95% CI 0.8
to 9.0) of BMD was found above the acetabular component in W1 and
10.2% (95% CI 0.9 to 19.4) and 9.1% (95% CI 3.8 to 14.4) medial
to the implant in W2 for resurfaced replacements and THRs respectively.
Resurfacing resulted in a mean loss of BMD of 6.7% (95% CI 0.7 to
12.7) in W3 but the BMD inferior to the acetabular component was
maintained in both groups. These results suggest that the ability of a resurfacing hip replacement
to preserve BMD only applies to the femoral side.
We inserted an electrode up the femoral neck into the femoral head of ten patients undergoing a metal-on-metal hip resurfacing arthroplasty through a posterior surgical approach and measured the oxygen concentration during the operation. In every patient the blood flow was compromised during surgery, but the extent varied. In three patients, the oxygen concentration was zero at the end of the procedure. The surgical approach caused a mean 60% drop (p <
0.005) in oxygen concentration while component insertion led to a further 20% drop (p <
0.04). The oxygen concentration did not improve significantly on wound closure. This study demonstrates that during hip resurfacing arthroplasty, patients experience some compromise to their femoral head blood supply and some have complete disruption.
A review of the current literature shows that there is a lack of consensus regarding the treatment of spondylolysis and spondylolisthesis in children and adolescents. Most of the views and recommendations provided in various reports are weakly supported by evidence. There is a limited amount of information about the natural history of the condition, making it difficult to compare the effectiveness of various conservative and operative treatments. This systematic review summarises the current knowledge on spondylolysis and spondylolisthesis and attempts to present a rational approach to the evaluation and management of this condition in children and adolescents.
We performed a series of 16 anatomical dissections
on Caucasian cadaver material to determine the surgical anatomy
of the medial femoral circumflex artery (MFCA) and its anastomoses.
These confirmed that the femoral head receives its blood supply
primarily from the MFCA via a group of posterior superior nutrient
arteries and the posterior inferior nutrient artery. In terms of
anastomoses that may also contribute to the blood supply, the anastomosis
with the inferior gluteal artery, via the piriformis branch, is
the most important. These dissections provide a base of knowledge
for further radiological studies on the vascularity of the normal
femoral head and its vascularity after dislocation of the hip.
We report a case of a male patient presenting
with bilateral painful but apparently well-positioned and -fixed
large-diameter metal-on-metal hip replacements four years post-operatively.
Multiple imaging modes revealed a thick-walled, cystic expansile
mass in communication with the hip joint (a pseudotumour). Implant
retrieval analysis and tissue culture eliminated high bearing wear
or infection as causes for the soft-tissue reaction, but noted marked corrosion
of the modular neck taper adaptor and corrosion products in the
tissues. Therefore, we believe corrosion products from the taper
caused by mismatch of the implant components led to pseudotumour
formation requiring revision.
We present the case of a 15-year-old boy with
symptoms due to Klippel–Feil syndrome. Radiographs and CT scans demonstrated
basilar impression, occipitalisation of C1 and fusion of C2/C3.
MRI showed ventral compression of the medullocervical junction.
Skull traction was undertaken pre-operatively to determine whether
the basilar impression could be safely reduced. During traction,
the C3/C4 junction migrated 12 mm caudally and spasticity resolved.
Peri-operative skull-femoral traction enabled posterior occipitocervical
fixation without decompression. Following surgery, cervical alignment
was restored and spasticity remained absent. One year after surgery
he was not limited in his activities.
The use of ultrasound-guided wire localisation of lesions is not well described in the orthopaedic literature. We describe a case of an impalpable schwannoma of the femoral nerve and another of sacroiliitis with an associated pelvic abscess. In both, surgical localisation was difficult. Peri-operative ultrasound-guided wire localisation was used to guide surgery and minimise tissue damage, thereby optimising the results and recovery of the patient.
The removal of all prosthetic material and a
two-stage revision procedure is the established standard management of
an infected total hip replacement (THR). However, the removal of
well-fixed femoral cement is time-consuming and can result in significant
loss of bone stock and femoral shaft perforation or fracture. We
report our results of two-stage revision THR for treating infection,
with retention of the original well-fixed femoral cement mantle
in 15 patients, who were treated between 1989 and 2002. Following
partial excision arthroplasty, patients received local and systemic
antibiotics and underwent reconstruction and re-implantation at
a second-stage procedure, when the infection had resolved. The mean follow-up of these 15 patients was 82 months (60 to
192). Two patients had positive microbiology at the second stage
and were treated with six weeks of appropriate antibiotics; one
of these developed recurrent infection requiring further revision.
Successful eradication of infection was achieved in the remaining
14 patients. We conclude that when two-stage revision is used for the treatment
of peri-prosthetic infection involving a THR, a well-fixed femoral
cement mantle can be safely left
A new anterior intrapelvic approach for the surgical
management of displaced acetabular fractures involving predominantly
the anterior column and the quadrilateral plate is described. In
order to establish five ‘windows’ for instrumentation, the extraperitoneal
space is entered along the lateral border of the rectus abdominis
muscle. This is the so-called ‘Pararectus’ approach. The feasibility
of safe dissection and optimal instrumentation of the pelvis was
assessed in five cadavers (ten hemipelves) before implementation
in a series of 20 patients with a mean age of 59 years (17 to 90),
of whom 17 were male. The clinical evaluation was undertaken between
December 2009 and December 2010. The quality of reduction was assessed
with post-operative CT scans and the occurrence of intra-operative
complications was noted. In the treatment of acetabular fractures predominantly involving
the anterior column and the quadrilateral plate, the Pararectus
approach allowed anatomical restoration with minimal morbidity related
to the surgical access.
We report the results of 62 hips in 62 patients
(17 males, 45 females) with mean age of 62.4 years (37 to 81), who underwent
revision of the acetabular component of a total hip replacement
due to aseptic loosening between May 2003 and November 2007. All
hips had a Paprosky type IIIa acetabular defect. Acetabular revision
was undertaken using a Procotyl E cementless oblong implant with
modular side plates and a hook combined with impaction allografting. At a mean follow-up of 60.5 months (36 to 94) with no patients
lost to follow-up and one died due to unrelated illness, the complication
rate was 38.7%. Complications included aseptic loosening (19 hips),
deep infection (3 hips), broken hook and side plate (one hip) and
a femoral nerve palsy (one hip). Further revision of the acetabular component
was required in 18 hips (29.0%) and a further four hips (6.4%) are
currently loose and awaiting revision. We observed unacceptably high rates of complication and failure
in our group of patients and cannot recommend this implant or technique.
Modern metal-on-metal hip resurfacing has been
widely performed in the United Kingdom for over a decade. However,
the literature reports conflicting views of the benefits: excellent
medium- to long-term results with some brands in specific subgroups,
but high failure rates and local soft-tissue reactions in others.
The National Joint Registry for England and Wales (NJR) has collected
data on all hip resurfacings performed since 2003. This retrospective
cohort study recorded survival time to revision from a resurfacing
procedure, exploring risk factors independently associated with
failure. All patients with a primary diagnosis of osteoarthritis
who underwent resurfacing between 2003 and 2010 were included in
the analyses. Cox’s proportional hazard models were used to analyse
the extent to which the risk of revision was related to patient,
surgeon and implant covariates. A total of 27 971 hip resurfacings were performed during the
study period, of which 1003 (3.59%) underwent revision surgery.
In the final adjusted model, we found that women were at greater
risk of revision than men (hazard ratio (HR) = 1.30, p = 0.007),
but the risk of revision was independent of age. Of the implant-specific
predictors, five brands had a significantly greater risk of revision
than the Birmingham Hip Resurfacing (BHR) (ASR: HR = 2.82, p <
0.001,
Conserve: HR = 2.03, p <
0.001, Cormet: HR = 1.43, p = 0.001,
Durom: HR = 1.67, p <
0.001, Recap: HR = 1.58, p = 0.007). Smaller
femoral head components were also significantly more likely to require
revision (≤ 44 mm: HR = 2.14, p <
0.001, 45 to 47 mm: HR = 1.48,
p = 0.001) than medium or large heads, as were operations performed
by low-volume surgeons (HR = 1.36, p <
0.001). Once these influences
had been removed, in 4873 male patients <
60 years old undergoing
resurfacing with a BHR, the five-year estimated risk of revision
was 1.59%. In summary, after adjustment for a range of covariates we found
that there were significant differences in the rate of failure between
brands and component sizes. Younger male patients had good five-year
implant survival when the BHR was used.
In patients with osteoporosis there is always
a strong possibility that pedicle screws will loosen. This makes
it difficult to select the appropriate osteoporotic patient for
a spinal fusion. The purpose of this study was to determine the
correlation between bone mineral density (BMD) and the magnitude
of torque required to insert a pedicle screw. To accomplish this,
181 patients with degenerative disease of the lumbar spine were
studied prospectively. Each underwent dual-energy x-ray absorptiometry
(DEXA) and intra-operative measurement of the torque required to
insert each pedicle screw. The levels of torque generated in patients
with osteoporosis and osteopenia were significantly lower than those
achieved in normal patients. Positive correlations were observed between
BMD and T-value at the instrumented lumbar vertebrae, mean BMD and
mean T-value of the lumbar vertebrae, and mean BMD and mean T-value
of the proximal femur. The predictive torque (Nm) generated during pedicle
screw insertion was [-0.127 + 1.62 × (BMD at the corresponding lumbar
vertebrae)], as measured by linear regression analysis. The positive
correlation between BMD and the maximum torque required to insert
a pedicle screw suggests that pre-operative assessment of BMD may
be useful in determining the ultimate strength of fixation of a
device, as well as the number of levels that need to be fixed with
pedicle screws in patients who are suspected of having osteoporosis.
We report the findings of an independent review
of 230 consecutive Birmingham hip resurfacings (BHRs) in 213 patients
(230 hips) at a mean follow-up of 10.4 years (9.6 to 11.7). A total
of 11 hips underwent revision; six patients (six hips) died from
unrelated causes; and 13 patients (16 hips) were lost to follow-up.
The survival rate for the whole cohort was 94.5% (95% confidence
interval (CI) 90.1 to 96.9). The survival rate in women was 89.1%
(95% CI 79.2 to 94.4) and in men was 97.5% (95% CI 92.4 to 99.2).
Women were 1.4 times more likely to suffer failure than men. For
each millimetre increase in component size there was a 19% lower
chance of a failure. The mean Oxford hip score was 45.0 (median
47.0, 28 to 48); mean University of California, Los Angeles activity
score was 7.4 (median 8.0, 3 to 9); mean patient satisfaction score
was 1.4 (median 1.0, 0 to 9). A total of eight hips had lysis in
the femoral neck and two hips had acetabular lysis. One hip had
progressive radiological changes around the peg of the femoral component.
There was no evidence of progressive neck narrowing between five
and ten years. Our results confirm that BHR provides good functional outcome
and durability for men, at a mean follow-up of ten years. We are
now reluctant to undertake hip resurfacing in women with this implant.
Inflammatory pseudotumours occasionally occur after metal-on-metal hip resurfacing and often lead to revision. Our aim was to determine the severity of this complication by assessing the outcome of revision in these circumstances and by comparing this with the outcome of other metal-on-metal hip resurfacing revisions as well as that of matched primary total hip replacements. We identified 53 hips which had undergone metal-on-metal hip resurfacing and required revision at a mean of 1.59 years (0.01 to 6.69) after operation. Of these, 16 were revised for pseudotumours, 21 for fracture and 16 for other reasons. These were matched by age, gender and diagnosis with 103 patients undergoing primary total hip replacement with the Exeter implant. At a mean follow-up of three years (0.8 to 7.2) the outcome of metal-on-metal hip resurfacing revision for pseudotumour was poor with a mean Oxford hip score of 20.9 ( The outcome of revision for pseudotumour is poor and consideration should be given to early revision to limit the extent of the soft-tissue destruction. The outcome of resurfacing revision for other causes is good.
The aim of this study was to investigate the
possible benefit of large-head metal-on-metal bearing on a stem
for primary hip replacement compared with a 28 mm diameter conventional
metal-on-polyethylene bearing in a prospective randomised controlled
trial. We investigated cemented stem behaviour between these two
different bearings using Einzel-Bild-Röntgen-Analyse, clinical and
patient reported measures (Harris hip score, Western Ontario and
McMaster Universities osteoarthritis index, Short Form-36 and satisfaction)
and whole blood metal ion levels at two years. A power study indicated
that 50 hips were needed in each group to detect subsidence of >
5 mm at two years with a
p-value of <
0.05. Significant improvement (p <
0.001) was found in the mean
clinical and patient reported outcomes at two years for both groups.
Comparison of outcomes between the groups at two years showed no
statistically significant difference for mean stem migration, clinical
and patient reported outcomes; except overall patient satisfaction which
was higher for metal-on-metal group (p = 0.05). Metal ion levels
were raised above the Medicines and Healthcare products Regulatory
Agency advised safety level (7 µg per litre) in 20% of the metal-on-metal
group and in one patient in metal-on-polyethylene group (who had
a metal-on-metal implant on the contralateral side). Two patients
in the metal-on-metal group were revised, one for pseudotumour and
one for peri-prosthetic fracture. Use of large modular heads is associated with a risk of raised
whole blood metal ion levels despite using a proven bearing from
resurfacing. The head-neck junction or excess stem micromotion are
possibly the weak links warranting further research.
Ceramic-on-ceramic bearings in hip replacement have low rates of wear and are increasingly being used in young adults. Our aim was to determine the incidence of audible phenomena or other bearing-related complications. We retrospectively analysed 250 ceramic-on-ceramic hip replacements in 224 patients which had been implanted between April 2000 and December 2007. The mean age of the patients at operation was 44 years (14 to 83) and all the operations were performed using the same surgical technique at a single centre. At a mean follow-up of 59 months (24 to 94), the mean Oxford hip score was 40.89 (11 to 48). There were six revisions, three of which were for impingement-related complications. No patient reported squeaking, but six described grinding or clicking, which was usually associated with deep flexion. No radiological evidence of osteolysis or migration of the components was observed in any hip. The early to mid-term results of contemporary ceramic-on-ceramic hip replacement show promising results with few concerns in terms of noise and squeaking. Positioning of the acetabular component remains critical in regard to the reduction of other impingement-related complications.