The August 2014 Knee Roundup360 looks at: re-admission following total knee replacement; out with the old and in with the new? computer navigation revisited; approach less important in knee replacement; is obesity driving a rise in knee replacements?; knee replacement isn’t cheap in the obese; cruciate substitution doesn’t increase knee flexion; and sonication useful diagnostic aid in two-stage revision.
We identified a group of patients from the Swedish
Arthroplasty Register who reported no relief of pain or worse pain
one year after a total knee replacement (TKR). A total of two different
patient-reported pain scores were used during this process. We then
evaluated how the instruments used to measure pain affected the
number of patients who reported no relief of pain or worse pain,
and the relative effect of potential risk factors. Between 2008 and 2010, 2883 TKRs were performed for osteoarthritis
in two Swedish arthroplasty units. After applying exclusion criteria,
2123 primary TKRs (2123 patients) were included in the study. The
Knee injury and Osteoarthritis Outcome Score (KOOS) and a Visual
Analogue Scale (VAS) for knee pain were used to assess patients pre-operatively
and one year post-operatively. Only 50 of the 220 patients (23%) who reported no pain relief
on either the KOOS pain subscale or the VAS for knee pain did so
with both of these instruments. Patients who reported no pain relief
on either measure tended to have less pain pre-operatively but a
higher degree of anxiety. Charnley category C was a predictor for
not gaining pain relief as measured on a VAS for knee pain. The number of patients who are not relieved of pain after a TKR
differs considerably depending on the instrument used to measure
pain. Cite this article:
Two types of fracture, early and late, have been
reported following limb lengthening in patients with achondroplasia (ACH)
and hypochondroplasia (HCH). We reviewed 25 patients with these conditions who underwent 72
segmental limb lengthening procedures involving the femur and/or
tibia, between 2003 and 2011. Gender, age at surgery, lengthened
segment, body mass index, the shape of the callus, the amount and
percentage of lengthening and the healing index were evaluated to determine
predictive factors for the occurrence of early (within three weeks
after removal of the fixation pins) and late fracture (>
three weeks
after removal of the pins). The Mann‑Whitney U test and Pearson’s
chi-squared test for univariate analysis and stepwise regression
model for multivariate analysis were used to identify the predictive factor
for each fracture. Only one patient (two tibiae) was excluded from
the analysis due to excessively slow formation of the regenerate,
which required supplementary measures. A total of 24 patients with
70 limbs were included in the study. There were 11 early fractures in eight patients. The shape of
the callus (lateral or central callus) was the only statistical
variable related to the occurrence of early fracture in univariate
and multivariate analyses. Late fracture was observed in six limbs
and the mean time between removal of the fixation pins and fracture
was 18.3 weeks (3.3 to 38.4). Lengthening of the tibia, larger healing
index, and lateral or central callus were related to the occurrence
of a late fracture in univariate analysis. A multivariate analysis
demonstrated that the shape of the callus was the strongest predictor
for late fracture (odds ratio: 19.3, 95% confidence interval: 2.91
to 128). Lateral or central callus had a significantly larger risk
of fracture than fusiform, cylindrical, or concave callus. Radiological monitoring of the shape of the callus during distraction
is important to prevent early and late fracture of lengthened limbs
in patients with ACH or HCH. In patients with thin callus formation,
some measures to stimulate bone formation should be considered as
early as possible. Cite this article:
The aims of this study were to compare the diagnostic test characteristics
of ultrasound alone, metal artefact reduction sequence MRI (MARS-MRI)
alone, and ultrasound combined with MARS-MRI for identifying intra-operative
pseudotumours in metal-on-metal hip resurfacing (MoMHR) patients
undergoing revision surgery. This retrospective diagnostic accuracy study involved 39 patients
(40 MoMHRs). The time between imaging modalities was a mean of 14.6
days (0 to 90), with imaging performed at a mean of 5.3 months (0.06
to 12) before revision. The prevalence of intra-operative pseudotumours
was 82.5% (n = 33).Aims
Methods
Acetabular component orientation in total hip arthroplasty (THA)
influences results. Intra-operatively, the natural arthritic acetabulum
is often used as a reference to position the acetabular component.
Detailed information regarding its orientation is therefore essential. The
aim of this study was to identify the acetabular inclination and
anteversion in arthritic hips. Acetabular inclination and anteversion in 65 symptomatic arthritic
hips requiring THA were measured using a computer navigation system.
All patients were Caucasian with primary osteoarthritis (29 men,
36 women). The mean age was 68 years (SD 8). Mean inclination was
50.5° (SD 7.8) in men and 52.1° (SD 6.7) in women. Mean anteversion
was 8.3° (SD 8.7) in men and 14.4° (SD 11.6) in women. Objectives
Methods
The accurate reconstruction of hip anatomy and
biomechanics is thought to be important in achieveing good clinical
outcomes following total hip arthroplasty (THA). To this end some
newer hip designs have introduced further modularity into the design
of the femoral component such that neckshaft angle and anteversion,
which can be adjusted intra-operatively. The clinical effect of
this increased modularity is unknown. We have investigated the changes
in these anatomical parameters following conventional THA with a
prosthesis of predetermined neck–shaft angle and assessed the effect
of changes in the hip anatomy on clinical outcomes. In total, 44 patients (mean age 65.3 years (standard deviation
( The mean pre-operative neck–shaft angle was significantly increased
by 2.8° from 128° ( Cite this article:
Several studies have reported the rate of post-operative
mortality after the surgical treatment of a fracture of the hip,
but few data are available regarding the delayed morbidity. In this
prospective study, we identified 568 patients who underwent surgery
for a fracture of the hip and who were followed for one year. Multivariate
analysis was carried out to identify possible predictors of mortality
and morbidity. The 30-day, four-month and one-year rates of mortality
were 4.3%, 11.4%, and 18.8%, respectively. General complications
and pre-operative comorbidities represented the basic predictors
of mortality at any time interval (p <
0.01). In-hospital, four-month
and one-year general complications occurred in 29.4%, 18.6% and
6.7% of patients, respectively. After adjusting for confounding variables,
comorbidities and poor cognitive status determined the likelihood
of early and delayed general complications, respectively (p <
0.001). Operative delay was the main predictor of the length of
hospital stay (p <
0.001) and was directly related to in-hospital
(p = 0.017) and four-month complications (p = 0.008). Cite this article:
Lumbar disc herniation (LDH) is uncommon in youth
and few cases are treated surgically. Very few outcome studies exist
for LDH surgery in this age group. Our aim was to explore differences
in gender in pre-operative level of disability and outcome of surgery
for LDH in patients aged ≤ 20 years using prospectively collected
data. From the national Swedish SweSpine register we identified 180
patients with one-year and 108 with two-year follow-up data ≤ 20
years of age, who between the years 2000 and 2010 had a primary
operation for LDH. Both male and female patients reported pronounced impairment
before the operation in all patient reported outcome measures, with
female patients experiencing significantly greater back pain, having
greater analgesic requirements and reporting significantly inferior
scores in EuroQol (EQ-5D-index), EQ-visual analogue scale, most aspects
of Short Form-36 and Oswestry Disabilities Index, when compared
with male patients. Surgery conferred a statistically significant
improvement in all registered parameters, with few gender discrepancies.
Quality of life at one year following surgery normalised in both
males and females and only eight patients (4.5%) were dissatisfied with
the outcome. Virtually all parameters were stable between the one-
and two-year follow-up examination. LDH surgery leads to normal health and a favourable outcome in
both male and female patients aged 20 years or younger, who failed
to recover after non-operative management. Cite this article:
Between 2003 and 2007, 99 knees in 77 patients
underwent opening wedge high tibial osteotomy. We evaluated the effect
of initial stable fixation combined with an artificial bone substitute
on the mid- to long-term outcome after medial opening-wedge high
tibial osteotomy (HTO) for medial compartmental osteoarthritis or
spontaneous osteonecrosis of the knee in 78 knees in 64 patients
available for review at a minimum of five years (mean age 68 years;
49 to 82). The mean follow-up was 6.5 years (5 to 10). The mean
Knee Society knee score and function score improved from 49.6 ( Opening-wedge HTO using a stable plate fixation system combined
with a bone substitute is a reliable procedure that provides excellent
results. Although this treatment might seem challenging for older
patients, our results strongly suggest that the results are equally
good. Cite this article:
The reported prevalence of an asymptomatic slip
of the contralateral hip in patients operated on for unilateral slipped
capital femoral epiphysis (SCFE) is as high as 40%. Based on a population-based
cohort of 2072 healthy adolescents (58% women) we report on radiological
and clinical findings suggestive of a possible previous SCFE. Common
threshold values for Southwick’s lateral head–shaft angle (≥ 13°)
and Murray’s tilt index (≥ 1.35) were used. New reference intervals
for these measurements at skeletal maturity are also presented. At follow-up the mean age of the patients was 18.6 years (17.2
to 20.1). All answered two questionnaires, had a clinical examination
and two hip radiographs. There was an association between a high head–shaft angle and
clinical findings associated with SCFE, such as reduced internal
rotation and increased external rotation. Also, 6.6% of the cohort
had Southwick’s lateral head–shaft angle ≥ 13°, suggestive of a
possible slip. Murray’s tilt index ≥ 1.35 was demonstrated in 13.1%
of the cohort, predominantly in men, in whom this finding was associated
with other radiological findings such as pistol-grip deformity or
focal prominence of the femoral neck, but no clinical findings suggestive
of SCFE. This study indicates that 6.6% of young adults have radiological
findings consistent with a prior SCFE, which seems to be more common
than previously reported. Cite this article:
We report our experience of revision total hip
replacement (THR) using the Revitan curved modular titanium fluted revision
stem in patients with a full spectrum of proximal femoral defects.
A total of 112 patients (116 revisions) with a mean age of 73.4
years (39 to 90) were included in the study. The mean follow-up
was 7.5 years (5.3 to 9.1). A total of 12 patients (12 hips) died
but their data were included in the survival analysis, and four
patients (4 hips) were lost to follow-up. The clinical outcome,
proximal bone regeneration and subsidence were assessed for 101
hips. The mean Harris Hip Score was 88.2 (45.8 to 100) after five years
and there was an increase of the mean Barnett and Nordin-Score,
a measure of the proximal bone regeneration, of 20.8 (-3.1 to 52.7).
Five stems had to be revised (4.3%), three (2.9%) showed subsidence,
five (4.3%) a dislocation and two of 85 aseptic revisions (2.3%)
a periprosthetic infection. At the latest follow-up, the survival with revision of the stem
as the endpoint was 95.7% (95% confidence interval 91.9% to 99.4%)
and with aseptic loosening as the endpoint, was 100%. Peri-prosthetic
fractures were not observed. We report excellent results with respect to subsidence, the risk
of fracture, and loosening after femoral revision using a modular
curved revision stem with distal cone-in-cone fixation. A successful
outcome depends on careful pre-operative planning and the use of
a transfemoral approach when the anatomy is distorted or a fracture
is imminent, or residual cement or a partially-secured existing
stem cannot be removed. The shortest appropriate stem should, in
our opinion, be used and secured with >
3 cm fixation at the femoral
isthmus, and distal interlocking screws should be used for additional
stability when this goal cannot be realised. Cite this article:
In this retrospective cohort study, we analysed
the incidence and functional outcome of a distal tibiofibular synostosis.
Patients with an isolated AO type 44-B or C fracture of the ankle
who underwent surgical treatment between 1995 and 2007 were invited
for clinical and radiological review. The American Orthopaedic Foot
and Ankle Society score, the American Academy of Orthopaedic Surgeons
score and a visual analogue score for pain were used to assess outcome. A total of 274 patients were available; the mean follow-up was
9.7 years (8 to 18). The extent of any calcification or synostosis
at the level of the distal interosseous membrane or syndesmosis
on the contemporary radiographs was defined as: no or minor calcifications
(group 1), severe calcification (group 2), or complete synostosis
(group 3). A total of 222 (81%) patients were in group 1, 37 (14%) in group
2 and 15 (5%) in group 3. There was no significant difference in
incidence between AO type 44-B and type 44-C fractures (p = 0.89).
Severe calcification or synostosis occurred in 21 patients (19%)
in whom a syndesmotic screw was used and in 31 (19%) in whom a syndesmotic screw
was not used.(p = 0.70). No significant differences were found between
the groups except for a greater reduction in mean dorsiflexion in
group 2 (p = 0.004). This is the largest study on distal tibiofibular synostosis,
and we found that a synostosis is a frequent complication of surgery
for a fracture of the ankle. Although it theoretically impairs the
range of movement of the ankle, it did not affect the outcome. Our findings suggest that synostosis of the distal tibiofibular
syndesmosis in general does not warrant treatment. Cite this article:
Stress shielding resulting in diminished bone
density following total knee replacement (TKR) may increase the
risk of migration and loosening of the prosthesis. This retrospective
study was designed to quantify the effects of the method of fixation
on peri-prosthetic tibial bone density beneath cemented and uncemented
tibial components of similar design and with similar long-term survival
rates. Standard radiographs taken between two months and 15 years
post-operatively were digitised from a matched group of TKRs using
cemented (n = 67) and uncemented (n = 67) AGC tibial prostheses.
Digital radiograph densitometry was used to quantify changes in
bone density over time. Age, length of follow-up, gender, body mass
index and alignment each significantly influenced the long-term
pattern of peri-prosthetic bone density. Similar long-term changes
in density irrespective of the method of fixation correlated well
with the high rate of survival of this TKR at 20 years, and suggest
that cemented and uncemented fixation are both equally viable. Cite this article:
Our aim was to compare the one-year post-operative
outcomes following retention or removal of syndesmotic screws in
adult patients with a fracture of the ankle that was treated surgically.
A total of 51 patients (35 males, 16 females), with a mean age of
33.5 years (16 to 62), undergoing fibular osteosynthesis and syndesmotic
screw fixation, were randomly allocated to retention of the syndesmotic
screw or removal at three months post-operatively. The two groups
were comparable at baseline. One year post-operatively, there was no significant difference
in the mean Olerud–Molander ankle score (82.4 retention We conclude that removal of a syndesmotic screw produces no significant
functional, clinical or radiological benefit in adult patients who
are treated surgically for a fracture of the ankle. Cite this article:
In an initial randomised controlled trial (RCT)
we segregated 180 patients to one of two knee positions following total
knee replacement (TKR): six hours of knee flexion using either a
jig or knee extension. Outcome measures included post-operative
blood loss, fall in haemoglobin, blood transfusion requirements,
knee range of movement, limb swelling and functional scores. A second
RCT consisted of 420 TKR patients randomised to one of three post-operative
knee positions: flexion for three or six hours post-operatively,
or knee extension. Positioning of the knee in flexion for six hours immediately
after surgery significantly reduced blood loss (p = 0.002). There
were no significant differences in post-operative range of movement,
swelling, pain or outcome scores between the various knee positions
in either study. Post-operative knee flexion may offer a simple
and cost-effective way to reduce blood loss and transfusion requirements
following TKR. We also report a cautionary note regarding the potential risks
of prolonged knee flexion for more than six hours observed during
clinical practice in the intervening period between the two trials,
with 14 of 289 patients (4.7%) reporting lower limb sensory neuropathy
at their three-month review. Cite this article:
There have been several studies examining the
association between the morphological characteristics seen in acetabular
dysplasia and the incidence of the osteoarthritis (OA). However, most studies focus mainly on acetabular morphological
analysis, and few studies have scrutinised the effect of femoral
morphology. In this study we enrolled 36 patients with bilateral
acetabular dysplasia and early or mid-stage OA in one hip and no
OA in the contralateral hip. CT scans were performed from the iliac
crest to 2 cm inferior to the tibial tuberosity, and the morphological
characteristics of both acetabulum and femur were studied. In addition, 200 hips in 100 healthy volunteer Chinese adults
formed a control group. The results showed that the dysplastic group
with OA had a significantly larger femoral neck anteversion and
a significantly shorter abductor lever arm than both the dysplastic
group without OA and the controls. Femoral neck anteversion had
a significant negative correlation with the length of the abductor
lever arm and we conclude that it may contribute to the development
of OA in dysplastic hips. Cite this article:
The aim of this prospective multicentre study
was to report the patient satisfaction after total knee replacement (TKR),
undertaken with the aid of intra-operative sensors, and to compare
these results with previous studies. A total of 135 patients undergoing
TKR were included in the study. The soft-tissue balance of each
TKR was quantified intra-operatively by the sensor, and 18 (13%)
were found to be unbalanced. A total of 113 patients (96.7%) in
the balanced group and 15 (82.1%) in the unbalanced group were satisfied
or very satisfied one year post-operatively (p = 0.043). A review of the literature identified no previous study with
a mean level of satisfaction that was greater than the reported
level of satisfaction of the balanced TKR group in this study. Ensuring
soft-tissue balance by using intra-operative sensors during TKR
may improve satisfaction. Cite this article:
This study compared the quality of reduction
and complication rate when using a standard ilioinguinal approach and
the new pararectus approach when treating acetabular fractures surgically.
All acetabular fractures that underwent fixation using either approach
between February 2005 and September 2014 were retrospectively reviewed
and the demographics of the patients, the surgical details and complications
were recorded. A total of 100 patients (69 men, 31 women; mean age 57 years,
18 to 93) who were consecutively treated were included for analysis.
The quality of reduction was assessed using standardised measurement
of the gaps and steps in the articular surface on pre- and post-operative
CT-scans. There were no significant differences in the demographics of
the patients, the surgical details or the complications between
the two approaches. A significantly better reduction of the gap,
however, was achieved with the pararectus approach (axial: p = 0.025,
coronal: p = 0.013, sagittal: p = 0.001). These data suggest that the pararectus approach is at least equal
to, or in the case of reduction of the articular gap, superior to
the ilioinguinal approach. This approach allows direct buttressing of the dome of the acetabulum
and the quadrilateral plate, which is particularly favourable in
geriatric fracture patterns. Cite this article:
The Oxford knee score (OKS) is a validated and
widely accepted disease-specific patient-reported outcome measure,
but there is limited evidence regarding any long-term trends in
the score. We reviewed 5600 individual OKS questionnaires (1547
patients) from a prospectively-collected knee replacement database,
to determine the trends in OKS over a ten-year period following
total knee replacement. The mean OKS pre-operatively was 19.5 (95%
confidence interval (CI) 18.8 to 20.2). The maximum post-operative
OKS was observed at two years (mean score 34.4 (95% CI 33.7 to 35.2)),
following which a gradual but significant decline was observed through
to the ten-year assessment (mean score 30.1 (95% CI 29.1 to 31.1))
(p <
0.001). A similar trend was observed for most of the individual
OKS components (p <
0.001). Kneeling ability initially improved
in the first year but was then followed by rapid deterioration (p
<
0.001). Pain severity exhibited the greatest improvement, although
residual pain was reported in over two-thirds of patients post-operatively,
and peak improvement in the night pain component did not occur until
year four. Post-operative OKS was lower for women (p <
0.001),
those aged <
60 years (p <
0.003) and those with a body mass
index >
35 kg/m2 (p <
0.014), although similar changes
in scores were observed. This information may assist surgeons in
advising patients of their expected outcomes, as well as providing
a comparative benchmark for evaluating longer-term outcomes following
knee replacement. Cite this article:
We examined patient and surgical factors associated
with deep surgical site infection (SSI) following total hip replacement
(THR) in a large integrated healthcare system. A retrospective review
of a cohort of primary THRs performed between 2001 and 2009 was
conducted. Patient characteristics, surgical details, surgeon and
hospital volumes, and SSIs were identified using the Kaiser Permanente
Total Joint Replacement Registry (TJRR). Proportional-hazard regression
models were used to assess risk factors for SSI. The study cohort
consisted of 30 491 THRs, of which 17 474 (57%) were performed on
women. The mean age of the patients in the whole series was 65.5
years (13 to 97; A comprehensive infection surveillance system, combined with
a TJRR, identified patient and surgical factors associated with
SSI. Obesity and chronic medical conditions should be addressed
prior to THR. The finding of increased SSI risk with bilateral THR
requires further investigation.