We compared the performance of uncemented trabecular metal tibial components in total knee replacement with that of cemented tibial components in patients younger than 60 years over two years using radiostereophotogrammetric analysis (RSA). A total of 22 consecutive patients (mean age 53 years, 33 to 59, 26 knees) received an uncemented NexGen trabecular metal cruciate-retaining monobloc tibial component and 19 (mean 53 years, 44 to 59, 21 knees) a cemented NexGen Option cruciate-retaining modular tibial component. All the trabecular metal components migrated during the initial three months and then stabilised. The exception was external rotation, which did not stabilise until 12 months. Unlike conventional metal-backed implants which displayed a tilting migration comprising subsidence and lift-off from the tibial tray, most of the trabecular metal components showed subsidence only, probably due to the elasticity of the implant. This pattern of subsidence is regarded as being beneficial for uncemented fixation.
The optimal method of tibial component fixation remains uncertain
in total knee arthroplasty (TKA). Hydroxyapatite coatings have been
applied to improve bone ingrowth in uncemented designs, but may
only coat the directly accessible surface. As peri-apatite (PA)
is solution deposited, this may increase the coverage of the implant
surface and thereby fixation. We assessed the tibial component fixation
of uncemented PA-coated TKAs Patients were randomised to PA-coated or cemented TKAs. In 60
patients (30 in each group), radiostereometric analysis of tibial
component migration was evaluated as the primary outcome at baseline,
three months post-operatively and at one, two and five years. A
linear mixed-effects model was used to analyse the repeated measurements.Aims
Patients and Methods
The June 2015 Knee Roundup360 looks at: Cruciate substituting
Unicompartmental knee arthroplasty (UKA) is a potential treatment
for isolated bone on bone osteoarthritis when limited to a single
compartment. The risk for revision of UKA is three times higher
than for total knee arthroplasty (TKA). The aim of this review was
to discuss the different revision options after UKA failure. A search was performed for English language articles published
between 2006 and 2016. After reviewing titles and abstracts, 105
papers were selected for further analysis. Of these, 39 papers were
deemed to contain clinically relevant data to be included in this review.Objectives
Materials and Methods
Debate has raged over whether a cruciate retaining
(CR) or a posterior stabilised (PS) total knee replacement (TKR) provides
a better range of movement (ROM) for patients. Various sub-sets
of CR design are frequently lumped together when comparing outcomes.
Additionally, multiple factors have been proven to influence the
rate of manipulation under anaesthetic (MUA) following TKR. The
purpose of this study was to determine whether different CR bearing
insert designs provide better ROM or different MUA rates. All primary
TKRs performed by two surgeons between March 2006 and March 2009
were reviewed and 2449 CR-TKRs were identified. The same CR femoral
component, instrumentation, and tibial base plate were consistently
used. In 1334 TKRs a CR tibial insert with 3° posterior slope and
no posterior lip was used (CR-S). In 803 there was an insert with
no slope and a small posterior lip (CR-L) and in 312 knees the posterior
cruciate ligament (PCL) was either resected or lax and a deep-dish,
anterior stabilised insert was used (CR-AS). More CR-AS inserts
were used in patients with less pre-operative ROM and greater pre-operative
tibiofemoral deformity and flexion contracture (p <
0.05). The
mean improvement in ROM was highest for the CR-AS inserts (5.9°
(-40° to 55°) Cite this article:
The Advance Medial-Pivot total knee arthroplasty (TKA) was designed
to reflect contemporary data regarding the kinematics of the knee.
We wished to examine the long-term results obtained with this prosthesis
by extending a previous evaluation. We retrospectively evaluated prospectively collected data from
225 consecutive patients (41 men and 184 women; mean age at surgery
71 years, 52 to 84) who underwent 284 TKAs with a mean follow-up
of 13.4 years (11 to 15). Implant failure, complication rate, clinical (both
subjective and objective) and radiological outcome were assessed.
Pre- and post-operative clinical and radiographic data were available
at regular intervals for all patients. A total of ten patients (4.4%;
ten TKAs) were lost to follow-up.Aims
Patients and Methods
Risk of revision following total knee arthroplasty (TKA) is higher
in patients under 55 years, but little data are reported regarding
non-revision outcomes. This study aims to identify predictors of
dissatisfaction in these patients. We prospectively assessed 177 TKAs (157 consecutive patients,
99 women, mean age 50 years; 17 to 54) from 2008 to 2013. Age, gender,
implant, indication, body mass index (BMI), social deprivation,
range of movement, Kellgren-Lawrence (KL) grade of osteoarthritis
(OA) and prior knee surgery were recorded. Pre- and post-operative
Oxford Knee Score (OKS) as well as Short Form-12 physical (PCS)
and mental component scores were obtained. Post-operative range
of movement, complications and satisfaction were measured at one
year.Aims
Patients and Methods
This study investigated the influence of body mass index (BMI)
on the post-operative fall in the level of haemoglobin (Hb), length
of hospital stay (LOS), 30-day re-admission rate, functional outcome
and quality of life, two years after total knee arthroplasty (TKA). A total of 7733 patients who underwent unilateral primary TKA
between 2001 and 2010 were included. The mean age was 67 years (30
to 90). There were 1421 males and 6312 females. The patients were
categorised into three groups: BMI <
25.0 kg/m2 (normal);
BMI between 25.0 and 39.9 kg/m2 (obese); and BMI ≥ 40.0
kg/m2 (morbidly obese).Aims
Patients and Methods
Our aim was to compare kinematic with mechanical alignment in
total knee arthroplasty (TKA). We performed a prospective blinded randomised controlled trial
to compare the functional outcome of patients undergoing TKA in
mechanical alignment (MA) with those in kinematic alignment (KA).
A total of 71 patients undergoing TKA were randomised to either
kinematic (n = 36) or mechanical alignment (n = 35). Pre- and post-operative
hip-knee-ankle radiographs were analysed. The knee injury and osteoarthritis
outcome score (KOOS), American Knee Society Score, Short Form-36,
Euro-Qol (EQ-5D), range of movement (ROM), two minute walk, and timed
up and go tests were assessed pre-operatively and at six weeks,
three and six months and one year post-operatively.Aims
Patients and Methods
The outcome of total knee replacement (TKR) using
components designed to increase the range of flexion is not fully
understood. The short- to mid-term risk of aseptic revision in high
flexion TKR was evaluated. The endpoint of the study was aseptic
revision and the following variables were investigated: implant
design (high flexion In a cohort of 64 000 TKRs, high flexion components were used
in 8035 (12.5%). The high flexion knees with tibial liners of thickness
>
14 mm had a density of revision of 1.45/100 years of observation,
compared with 0.37/100 in non-high flexion TKR with liners ≤ 14
mm thick. Relative to a standard fixed PS TKR, the NexGen (Zimmer,
Warsaw, Indiana) Gender Specific Female high flexion fixed PS TKR
had an increased risk of revision (hazard ratio (HR) 2.27 (95% confidence
interval (CI) 1.48 to 3.50)), an effect that was magnified when
a thicker tibial insert was used (HR 8.10 (95% CI 4.41 to 14.89)). Surgeons should be cautious when choosing high flexion TKRs,
particularly when thicker tibial liners might be required. Cite this article:
The role of computer-assisted surgery in maintaining the level of the joint in primary knee joint replacement (TKR) has not been well defined. We undertook a blinded randomised controlled trial comparing joint-line maintenance, functional outcomes, and quality-of-life outcomes between patients undergoing computer-assisted and conventional TKR. A total of 115 patients were randomised (computer-assisted, n = 55; conventional, n = 60). Two years post-operatively no significant correlation was found between computer-assisted and conventional surgery in terms of maintaining the joint line. Those TKRs where the joint line was depressed post-operatively improved the least in terms of functional scores. No difference was detected in terms of quality-of-life outcomes. Change in joint line was found to be related to change in alignment. Change in alignment significantly affects change in joint line and functional scores.
The purpose of this study was to compare clinical
outcomes of total knee arthroplasty (TKA) after manipulation under
anaesthesia (MUA) for post-operative stiffness with a matched cohort
of TKA patients who did not requre MUA. In total 72 patients (mean age 59.8 years, 42 to 83) who underwent
MUA following TKA were identified from our prospective database
and compared with a matched cohort of patients who had undergone
TKA without subsequent MUA. Patients were evaluated for range of
movement (ROM) and clinical outcome scores (Western Ontario and
McMaster Universities Arthritis Index, Short-Form Health Survey,
and Knee Society Clinical Rating System) at a mean follow-up of
36.4 months (12 to 120). MUA took place at a mean of nine weeks
(5 to 18) after TKA. In patients who required MUA, mean flexion
deformity improved from 10° (0° to 25°) to 4.4° (0° to 15°) (p <
0.001),
and mean range of flexion improved from 79.8° (65° to 95°) to 116°
(80° to 130°) (p <
0.001). There were no statistically significant
differences in ROM or functional outcome scores at three months,
one year, or two years between those who required MUA and those
who did not. There were no complications associated with manipulation At most recent follow-up, patients requiring MUA achieved equivalent
ROM and clinical outcome scores when compared with a matched control
group. While other studies have focused on ROM after manipulation,
the current study adds to current literature by supplementing this
with functional outcome scores. Cite this article:
The aims of this study were to determine the proportion of patients
with outlier varus or valgus alignment in kinematically aligned
total knee arthroplasty (TKA), whether those with outlier varus
or valgus alignment have higher forces in the medial or lateral
compartments of the knee than those with in-range alignment and
whether measurements of the alignment of the limb, knee and components
predict compartment forces. The intra-operative forces in the medial and lateral compartments
were measured with an instrumented tibial insert in 67 patients
who underwent a kinematically aligned TKA during passive movement.
The mean of the forces at full extension, 45° and 90° of flexion
determined the force in the medial and lateral compartments. Measurements
of the alignment of the limb and the components included the hip-knee-ankle
(HKA) angle, proximal medial tibial angle (PMTA), and distal lateral
femoral angle (DLFA). Measurements of the alignment of the knee
and the components included the tibiofemoral angle (TFA), tibial
component angle (TCA) and femoral component angle (FCA). Alignment was
measured on post-operative, non-weight-bearing anteroposterior (AP)
scanograms and categorised as varus or valgus outlier or in-range
in relation to mechanically aligned criteria.Aims
Patients and Methods
Primary total knee arthroplasty (TKA) is a reliable
procedure with reproducible long-term results. Nevertheless, there
are conditions related to the type of patient or local conditions
of the knee that can make it a difficult procedure. The most common
scenarios that make it difficult are discussed in this review. These
include patients with many previous operations and incisions, and
those with severe coronal deformities, genu recurvatum, a stiff knee,
extra-articular deformities and those who have previously undergone
osteotomy around the knee and those with chronic dislocation of
the patella. Each condition is analysed according to the characteristics of
the patient, the pre-operative planning and the reported outcomes. When approaching the difficult primary TKA surgeons should use
a systematic approach, which begins with the review of the existing
literature for each specific clinical situation. Cite this article:
Total knee arthroplasty (TKA) is an established
and successful procedure. However, the design of prostheses continues
to be modified in an attempt to optimise the functional outcome
of the patient. The aim of this study was to determine if patient outcome after
TKA was influenced by the design of the prosthesis used. A total of 212 patients (mean age 69; 43 to 92; 131 female (62%),
81 male (32%)) were enrolled in a single centre double-blind trial
and randomised to receive either a Kinemax (group 1) or a Triathlon
(group 2) TKA. Patients were assessed pre-operatively, at six weeks, six months,
one year and three years after surgery. The outcome assessments
used were the Oxford Knee Score; range of movement; pain numerical
rating scales; lower limb power output; timed functional assessment
battery and a satisfaction survey. Data were assessed incorporating
change over all assessment time points, using repeated measures
analysis of variance longitudinal mixed models. Implant group 2
showed a significantly greater range of movement (p = 0.009), greater
lower limb power output (p = 0.026) and reduced report of ‘worst
daily pain’ (p = 0.003) over the three years of follow-up. Differences
in Oxford Knee Score (p = 0.09), report of ‘average daily pain’
(p = 0.57) and timed functional performance tasks (p = 0.23) did
not reach statistical significance. Satisfaction with outcome was
significantly better in group 2 (p = 0.001). These results suggest that patient outcome after TKA can be influenced
by the prosthesis used. Cite this article:
The role of high tibial osteotomy (HTO) is being questioned by
the use of unicompartmental knee arthroplasty (UKA) in the treatment
of medial compartment femorotibial osteoarthritis. Our aim was to
compare the outcomes of revision HTO or UKA to a total knee arthroplasty
(TKA) using computer-assisted surgery in matched groups of patients. We conducted a retrospective study to compare the clinical and
radiological outcome of patients who underwent revision of a HTO
to a TKA (group 1) with those who underwent revision of a medial
UKA to a TKA (group 2). All revision procedures were performed using
computer-assisted surgery. We extracted these groups of patients
from our database. They were matched by age, gender, body mass index,
follow-up and pre-operative functional score. The outcomes included
the Knee Society Scores (KSS), radiological outcomes and the rate
of further revision.Aims
Patients and Methods
Radiological evidence of post-traumatic osteoarthritis
(PTOA) after fracture of the tibial plateau is common but end-stage arthritis
which requires total knee arthroplasty is much rarer. The aim of this study was to examine the indications for, and
outcomes of, total knee arthroplasty after fracture of the tibial
plateau and to compare this with an age and gender-matched cohort
of TKAs carried out for primary osteoarthritis. Between 1997 and 2011, 31 consecutive patients (23 women, eight
men) with a mean age of 65 years (40 to 89) underwent TKA at a mean
of 24 months (2 to 124) after a fracture of the tibial plateau.
Of these, 24 had undergone ORIF and seven had been treated non-operatively.
Patients were assessed pre-operatively and at 6, 12 and >
60 months
using the Short Form-12, Oxford Knee Score and a patient satisfaction
score. Patients with instability or nonunion needed total knee arthroplasty
earlier (14 and 13.3 months post-injury) than those with intra-articular
malunion (50 months, p <
0.001). Primary cruciate-retaining implants
were used in 27 (87%) patients. Complication rates were higher in
the PTOA cohort and included wound complications (13% Total knee arthroplasty undertaken after fracture of the tibial
plateau has a higher rate of complications than that undertaken
for primary osteoarthritis, but patient-reported outcomes and satisfaction
are comparable. Cite this article:
Total knee arthroplasty (TKA) is known to lead
to a reduction in periprosthetic bone mineral density (BMD). In theory,
this may lead to migration, instability and aseptic loosening of
the prosthetic components. Bisphosphonates inhibit bone resorption
and may reduce this loss in BMD. We hypothesised that treatment
with bisphosphonates and calcium would lead to improved BMD and
clinical outcomes compared with treatment with calcium supplementation
alone following TKA. A total of 26 patients, (nine male and 17 female,
mean age 67 years) were prospectively randomised into two study
groups: alendronate and calcium (bisphosphonate group, n = 14) or calcium
only (control group, n = 12). Dual energy X-ray absorptiometry (DEXA)
measurements were performed post-operatively, and at three months,
six months, one, two, four, and seven years post-operatively. Mean femoral metaphyseal BMD was significantly higher in the
bisphosphonate group compared with controls, up to four years following
surgery in some areas of the femur (p = 0.045). BMD was observed
to increase in the lateral tibial metaphysis in the bisphosphonate
group until seven years (p = 0.002), and was significantly higher than
that observed in the control group throughout (p = 0.024). There
were no significant differences between the groups in the central
femoral metaphyseal, tibial medial metaphyseal or diaphyseal regions
of interest (ROI) of either the femur or tibia. Bisphosphonate treatment after TKA may be of benefit for patients
with poor bone quality. However, further studies with a larger number
of patients are necessary to assess whether this is clinically beneficial. Cite this article:
Bone loss in the proximal tibia and distal femur
is frequently encountered in revision knee replacement surgery.
The various options for dealing with this depend on the extent of
any bone loss. We present our results with the use of cementless
metaphyseal metal sleeves in 103 patients (104 knees) with a mean
follow-up of 43 months (30 to 65). At final follow-up, sleeves in
102 knees had good osseointegration. Two tibial sleeves were revised
for loosening, possibly due to infection. The average pre-operative Oxford Knee Score was 23 (11 to 36)
and this improved to 32 (15 to 46) post-operatively. These early
results encourage us to continue with the technique and monitor
the outcomes in the long term. Cite this article:
The purpose of the present study was to examine the long-term
fixation of a cemented fixed-bearing polished titanium tibial baseplate
(Genesis ll). Patients enrolled in a previous two-year prospective trial (n
= 35) were recalled at ten years. Available patients (n = 15) underwent
radiostereometric analysis (RSA) imaging in a supine position using
a conventional RSA protocol. Migration of the tibial component in
all planes was compared between initial and ten-year follow-up.
Outcome scores including the Knee Society Score, Western Ontario
and McMaster Universities Arthritis Index, 12-item Short Form Health
Survey, Forgotten Joint Score, and University of California, Los
Angeles Activity Score were recorded.Aims
Patients and Methods
