Aseptic loosening of the femoral component is
an important indication for revision surgery in unicompartmental knee
replacement (UKR). A new design of femoral component with an additional
peg was introduced for the cemented Oxford UKR to increase its stability.
The purpose of this study was to compare the primary stability of
the two designs of component. Medial Oxford UKR was performed in 12 pairs of human cadaver
knees. In each pair, one knee received the single peg and one received
the twin peg design. Three dimensional micromotion and subsidence
of the component in relation to the bone was measured under cyclical
loading at flexion of 40° and 70° using an optical measuring system.
Wilcoxon matched pairs signed-rank test was performed to detect
differences between the two groups. There was no significant difference in the relative micromotion
(p = 0.791 and 0.380, respectively) and subsidence (p = 0.301 and
0.176, respectively) of the component between the two groups at
both angles of flexion. Both designs of component offered good strength
of fixation in this cadaver study. Cite this article:
It has recently been reported that the transverse
acetabular ligament (TAL) is helpful in determining the position
of the acetabular component in total hip replacement (THR). In this
study we used a computer-assisted navigation system to determine
whether the TAL is useful as a landmark in THR. The study was carried
out in 121 consecutive patients undergoing primary THR (134 hips),
including 67 dysplastic hips (50%). There were 26 men (29 hips)
and 95 women (105 hips) with a mean age of 60.2 years (17 to 82)
at the time of operation. After identification of the TAL, its anteversion
was measured intra-operatively by aligning the inferomedial rim
of the trial acetabular component with the TAL using computer-assisted
navigation. The TAL was identified in 112 hips (83.6%). Intra-observer reproducibility
in the measurement of anteversion of the TAL was high, but inter-observer
reproducibility was moderate. Each surgeon was able to align the trial component according
to the target value of the angle of anteversion of the TAL, but
it was clear that methods may differ among surgeons. Of the measurements
of the angle of anteversion of the TAL, 5.4% (6 of 112 hips) were
outliers from the safe zone. In summary, we found that the TAL is useful as a landmark when
implanting the acetabular component within the safe zone in almost
all hips, and to prevent it being implanted in retroversion in all
hips, including dysplastic hips. However, as anteversion of the
TAL may be excessive in a few hips, it is advisable to pay attention
to individual variations, particularly in those with severe posterior
pelvic tilt. Cite this article:
The December 2014 Foot &
Ankle Roundup360 looks at: Charcot feet, biomarkers and diabetes; weight bearing following Achilles tendon rupture; endobuttons and mal-reduced diastasis; evidence for stem cell therapies in osteochondral lesions of the talus; syndesmosis fixation in SER ankle fractures; and self-reporting for foot and ankle outcomes.
Total hip replacement (THR) after acetabular
fracture presents unique challenges to the orthopaedic surgeon.
The majority of patients can be treated with a standard THR, resulting
in a very reasonable outcome. Technical challenges however include
infection, residual pelvic deformity, acetabular bone loss with
ununited fractures, osteonecrosis of bone fragments, retained metalwork,
heterotopic ossification, dealing with the sciatic nerve, and the
difficulties of obtaining long-term acetabular component fixation.
Indications for an acute THR include young patients with both femoral
head and acetabular involvement with severe comminution that cannot
be reconstructed, and the elderly, with severe bony comminution.
The outcomes of THR for established post-traumatic arthritis include
excellent pain relief and functional improvements. The use of modern
implants and alternative bearing surfaces should improve outcomes
further. Cite this article:
We retrospectively evaluated the clinical and
radiological outcomes of a consecutive cohort of patients aged >
70 years with a displaced fracture of the olecranon, which was treated
non-operatively with early mobilisation. We identified 28 such patients
(27 women) with a mean age of 82 years (71 to 91). The elbow was
initially immobilised in an above elbow cast in 90° of flexion of
the elbow for a mean of five days. The cast was then replaced by
a sling. Active mobilisation was encouraged as tolerated. No formal
rehabilitation was undertaken. At a mean follow-up of 16 months
(12 to 26), the mean ranges of flexion and extension were 140° and
15° respectively. On a visual analogue scale of 1 (no pain) to 10,
the mean pain score was 1 (0 to 8). Of the original 28 patients
22 developed nonunion, but no patients required surgical treatment. We conclude that non-operative functional treatment of displaced
olecranon fractures in the elderly gives good results and a high
rate of satisfaction. 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:
Stems may improve fixation and stability of components
during revision total knee replacement. However, the choice between
cemented and cementless stems is not a clear one. Cemented stems
offer several advantages in terms of versatility, mechanical stability, surgical
technique and clinical outcome over their cementless counterpart. Cite this article:
In this study we randomised 140 patients who
were due to undergo primary total knee arthroplasty (TKA) to have the
procedure performed using either patient-specific cutting guides
(PSCG) or conventional instrumentation (CI). The primary outcome measure was the mechanical axis, as measured
at three months on a standing long-leg radiograph by the hip–knee–ankle
(HKA) angle. This was undertaken by an independent observer who
was blinded to the instrumentation. Secondary outcome measures were
component positioning, operating time, Knee Society and Oxford knee
scores, blood loss and length of hospital stay. A total of 126 patients (67 in the CI group and 59 in the PSCG
group) had complete clinical and radiological data. There were 88
females and 52 males with a mean age of 69.3 years (47 to 84) and
a mean BMI of 28.6 kg/m2 (20.2 to 40.8). The mean HKA
angle was 178.9° (172.5 to 183.4) in the CI group and 178.2° (172.4
to 183.4) in the PSCG group (p = 0.34). Outliers were identified
in 22 of 67 knees (32.8%) in the CI group and 19 of 59 knees (32.2%)
in the PSCG group (p = 0.99). There was no significant difference
in the clinical results (p = 0.95 and 0.59, respectively). Operating time,
blood loss and length of hospital stay were not significantly reduced
(p = 0.09, 0.58 and 0.50, respectively) when using PSCG. The use of PSCG in primary TKA did not reduce the proportion
of outliers as measured by post-operative coronal alignment. Cite this article:
Instability after total knee replacement (TKR)
accounts for 10% to 22% of revision procedures. All patients who
present for evaluation of instability require a thorough history to
be taken and physical examination, as well as appropriate imaging.
Deep periprosthetic infection must be ruled out by laboratory testing
and an aspiration of the knee must be carried out. The three main
categories of instability include flexion instability, extension instability
(symmetric and asymmetric), and genu recurvatum. Most recently,
the aetiologies contributing to, and surgical manoeuvres required
to correct, flexion instability have been elucidated. While implant
design and patient-related factors may certainly contribute to the
aetiology, surgical technique is also a significant factor in all
forms of post-operative instability. Cite this article:
Back pain is a common symptom in children and
adolescents. Here we review the important causes, of which defects
and stress reactions of the pars interarticularis are the most common
identifiable problems. More serious pathology, including malignancy
and infection, needs to be excluded when there is associated systemic
illness. Clinical evaluation and management may be difficult and
always requires a thorough history and physical examination. Diagnostic
imaging is obtained when symptoms are persistent or severe. Imaging
is used to reassure the patient, relatives and carers, and to guide
management. Cite this article:
Charcot neuro-osteoarthropathy (CN) of the midfoot
presents a major reconstructive challenge for the foot and ankle
surgeon. The Synthes 6 mm Midfoot Fusion Bolt is both designed and
recommended for patients who have a deformity of the medial column
of the foot due to CN. We present the results from the first nine
patients (ten feet) on which we attempted to perform fusion of the
medial column using this bolt. Six feet had concurrent hindfoot fusion
using a retrograde nail. Satisfactory correction of deformity of
the medial column was achieved in all patients. The mean correction
of calcaneal pitch was from 6°
(-15° to +18°) pre-operatively to 16° (7° to 23°) post-operatively;
the mean Meary angle from 26° (3° to 46°) to 1° (1° to 2°); and
the mean talometatarsal angle on dorsoplantar radiographs from 27°
(1° to 48°) to 1° (1° to 3°). However, in all but two feet, at least one joint failed to fuse.
The bolt migrated in six feet, all of which showed progressive radiographic
osteolysis, which was considered to indicate loosening. Four of
these feet have undergone a revision procedure, with good radiological
evidence of fusion. The medial column bolt provided satisfactory correction
of the deformity but failed to provide adequate fixation for fusion
in CN deformities in the foot. In its present form, we cannot recommend the routine use of this
bolt. Cite this article:
Surgical interventions consisting of internal
fixation (IF) or total hip replacement (THR) are required to restore
patient mobility after hip fractures. Conventionally, this decision
was based solely upon the degree of fracture displacement. However,
in the last ten years, there has been a move to incorporate patient
characteristics into the decision making process. Research demonstrating
that joint replacement renders superior functional results when compared
with IF, in the treatment of displaced femoral neck fractures, has
swayed the pendulum in favour of THR. However, a high risk of dislocation
has always been the concern. Fortunately, there are newer technologies
and alternative surgical approaches that can help reduce the risk
of dislocation. The authors propose an algorithm for the treatment
of femoral neck fractures: if minimally displaced, in the absence
of hip joint arthritis, IF should be performed; if arthritis is
present, or the fracture is displaced, then THR is preferred. Cite this article:
This study compares the outcomes of two methods
of fixation of displaced fractures of the radial neck. The 58 patients
with a mean age of 38.5 years (18 to 56), were treated in a non
randomised study with screws (n = 29) or a plate and screws (n =
29) according to the surgeon’s preference. The patients were reviewed at one year. Radiographs and functional
evaluations were carried out up to one year post-operatively, using
the Broberg and Morrey functional evaluation score, range of movement,
and assessment of complications. The mean functional scores did not differ significantly between
groups (90 (55 to 100) Cite this article:
Cemented femoral stems with force closed fixation
designs have shown good clinical results despite high early subsidence.
A new triple-tapered stem in this category (C-stem AMT) was introduced
in 2005. This study compares this new stem with an established stem
of similar design (Exeter) in terms of migration (as measured using radiostereometric
analysis), peri-prosthetic bone remodelling (measured using dual
energy x-ray densitometry, DXA), Oxford Hip Score, and plain radiographs. A total of 70 patients (70 hips) with a mean age of 66 years
(53 to 78) were followed for two years. Owing to missing data of
miscellaneous reasons, the final analysis represents data from 51
(RSA) and 65 (DXA) patients. Both stems showed a typical pattern
of migration: Subsidence and retroversion that primarily occurred
during the first three months. C-stem AMT subsided less during the
first three months (p = 0.01), before stabilising at a subsidence rate
similar to the Exeter stem from years one to two. The rate of migration
into retroversion was slightly higher for C-stem AMT during the
second year (p = 0.03). Whilst there were slight differences in
movement patterns between the stems, the C-stem AMT exhibits good
early clinical outcomes and displays a pattern of migration and
bone remodelling that predicts good clinical performance. Cite this article:
We compared the rate of revision for instability
after total hip replacement (THR) when lipped and non-lipped acetabular
liners were used. We hypothesised that the use of a lipped liner
in a modular uncemented acetabular component reduces the risk of
revision for instability after primary THR. Using data from the
New Zealand Joint Registry, we found that the use of a lipped liner
was associated with a significantly decreased rate of revision for instability
and for all other indications. Adjusting for the size of the femoral
head, the surgical approach and the age and gender of the patient,
this difference remained strongly significant (p <
0.001). We conclude that evidence from the New Zealand registry suggests
that the use of lipped liners with modular uncemented acetabular
components is associated with a decreased rate of revision for instability
after primary THR. Cite this article:
In this study we evaluated the results of midtarsal
release and open reduction for the treatment of children with convex
congenital foot (CCF) (vertical talus) and compared them with the
published results of peritalar release. Between 1977 and 2009, a
total of 22 children (31 feet) underwent this procedure. In 15 children
(48%) the CCF was isolated and in the remainder it was not (seven
with arthrogryposis, two with spinal dysraphism, one with a polymalformative
syndrome and six with an undefined neurological disorder). Pre-operatively, the mean tibiotalar angle was 150.2° (106° to
175°) and the mean calcaneal pitch angle was -19.3° (-72° to 4°).
The procedure included talonavicular and calcaneocuboid joint capsulotomies,
lengthening of tendons of tibialis anterior and the extensors of
the toes, allowing reduction of the midtarsal joints. Lengthening
of the Achilles tendon was necessary in 23 feet (74%). The mean follow-up was 11 years (2 to 21). The results, as assessed
by the Adelaar score, were good in 24 feet (77.4%), fair in six
(19.3%) and poor in one foot (3.3%), with no difference between
those with isolated CCF and those without. The mean American Orthopaedic
Foot and Ankle Society midfoot score was 89.9 (54 to 100) and 77.8
(36 to 93) for those with isolated CCF and those without, respectively.
At the final follow-up, the mean tibiotalar (120°; 90 to 152) and
calcaneal pitch angles (4°; -13 to 22) had improved significantly
(p <
0.0001). Dislocation of the talonavicular and calcaneocuboid
joints was completely reduced in 22 (70.9%) and 29 (93.6%) of feet,
respectively. Three children (five feet) underwent further surgery
at a mean of 8.5 years post-operatively, three with pes planovalgus
and two in whom the deformity had been undercorrected. No child
developed avascular necrosis of the talus. Midtarsal joint release and open reduction is a satisfactory
procedure, which may provide better results than peritalar release.
Complications include the development of pes planovalgus and persistent
dorsal subluxation of the talonavicular joint. Cite this article:
Previous studies of failure mechanisms leading
to revision total knee replacement (TKR) performed between 1986 and
2000 determined that many failed early, with a disproportionate
amount accounted for by infection and implant-associated factors
including wear, loosening and instability. Since then, efforts have
been made to improve implant performance and instruct surgeons in
best practice. Recently our centre participated in a multi-centre evaluation
of 844 revision TKRs from 2010 to 2011. The purpose was to report
a detailed analysis of failure mechanisms over time and to see if
failure modes have changed over the past 10 to 15 years. Aseptic
loosening was the predominant mechanism of failure (31.2%), followed
by instability (18.7%), infection (16.2%), polyethylene wear (10.0%),
arthrofibrosis (6.9%) and malalignment (6.6%). The mean time to
failure was 5.9 years (ten days to 31 years), 35.3% of all revisions
occurred at less than two years, and 60.2% in the first five years.
With improvements in implant and polyethylene manufacture, polyethylene
wear is no longer a leading cause of failure. Early mechanisms of
failure are primarily technical errors. In addition to improving
implant longevity, industry and surgeons must work together to decrease
these technical errors. All reports on failure of TKR contain patients
with unexplained pain who not infrequently have unmet expectations.
Surgeons must work to achieve realistic patient expectations pre-operatively,
and therefore, improve patient satisfaction post-operatively. Cite this article:
Total Of the 54 patients who underwent TES for a primary tumour between
1993 and 2010, 19 died and four were lost to follow-up. In January
2012, a questionnaire was sent to the 31 surviving patients. This
included the short form-36 to assess HRQoL and questions about the
current condition of their disease, activities of daily living (ADL)
and surgery. The response rate was high at 83.9% (26/31 patients).
We found that most patients were satisfied and maintained good performance
of their ADLs. The mental health status and social roles of the HRQoL scores
were nearly equivalent to those of healthy individuals, regardless
of the time since surgery. There was significant impairment of physical
health in the early post-operative years, but this usually returned
to normal approximately three years after surgery. Cite this article:
At least four ways have been described to determine
femoral component rotation, and three ways to determine tibial component
rotation in total knee replacement (TKR). Each method has its advocates
and each has an influence on knee kinematics and the ultimate short
and long term success of TKR. Of the four femoral component methods,
the author prefers rotating the femoral component in flexion to
that amount that establishes a stable symmetrical flexion gap. This
judgement is made after the soft tissues of the knee have been balanced
in extension. Of the three tibial component methods, the author prefers rotating
the tibial component into congruency with the established femoral
component rotation with the knee is in extension. This yields a
rotationally congruent articulation during weight-bearing and should
minimise the torsional forces being transferred through a conforming tibial
insert, which could lead to wear to the underside of the tibial
polyethylene. Rotating platform components will compensate for any
mal-rotation, but can still lead to pain if excessive tibial insert
rotation causes soft-tissue impingement. Cite this article:
We report our experience with glenohumeral arthrodesis
as a salvage procedure for epilepsy-related recurrent shoulder instability.
A total of six patients with epilepsy underwent shoulder fusion
for recurrent instability and were followed up for a mean of 39 months
(12 to 79). The mean age at the time of surgery was 31 years (22
to 38). Arthrodesis was performed after a mean of four previous
stabilisation attempts (0 to 11) in all but one patient in whom
the procedure was used as a primary treatment. All patients achieved
bony union, with a mean time to fusion of 2.8 months (2 to 7). There
were no cases of re-dislocation. One revision was undertaken for
loosening of the metalwork, and then healed satisfactorily. An increase
was noted in the mean subjective shoulder value, which improved
from 37 (5 to 50) pre-operatively to 42 (20 to 70) post-operatively
although it decreased in two patients. The mean Oxford shoulder
instability score improved from 13 pre-operatively (7 to 21) to
24 post-operatively (13 to 36). In our series, glenohumeral arthrodesis
eliminated recurrent instability and improved functional outcome. Fusion
surgery should therefore be considered in this patient population.
However, since the majority of patients are young and active, they
should be comprehensively counselled pre-operatively given the functional
deficit that results from the procedure. Cite this article: