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
We present the ten- to 15-year follow-up of 31
patients (34 knees), who underwent an Elmslie-Trillat tibial tubercle osteotomy
for chronic, severe patellar instability, unresponsive to non-operative
treatment. The mean age of the patients at the time of surgery was
31 years (18 to 46) and they were reviewed post-operatively, at
four years (2 to 8) and then at 12 years (10 to 15). All patients
had pre-operative knee radiographs and Cox and Insall knee scores. Superolateral
portal arthroscopy was performed per-operatively to document chondral
damage and after the osteotomy to assess the stability of the patellofemoral
joint. A total of 28 knees (82%) had a varying degree of damage
to the articular surface. At final follow-up 25 patients (28 knees)
were available for review and underwent clinical examination, radiographs
of the knee, and Cox and Insall scoring. Six patients who had no
arthroscopic chondral abnormality showed no or only early signs
of osteoarthritis on final radiographs; while 12 patients with lower
grade chondral damage (grade 1 to 2) showed early to moderate signs
of osteoarthritis and six out of ten knees with higher grade chondral
damage (grade 3 to 4) showed marked evidence of osteoarthritis;
four of these had undergone a knee replacement. In the 22 patients
(24 knees) with complete follow-up, 19 knees (79.2%) were reported
to have a good or excellent outcome at four years, while 15 knees
(62.5%) were reported to have the same at long-term follow-up. The
functional and radiological results show that the extent of pre-operatively
sustained chondral damage is directly related to the subsequent
development of patellofemoral osteoarthritis. Cite this article:
Valgus knee deformity can present a number of
unique surgical challenges for the total knee arthroplasty (TKA)
surgeon. Understanding the typical patterns of bone and soft-tissue pathology
in the valgus arthritic knee is critical for appropriate surgical
planning. This review aims to provide the knee arthroplasty surgeon
with an understanding of surgical management strategies for the
treatment of valgus knee arthritis. Lateral femoral and tibial deficiencies, contracted lateral soft
tissues, attenuated medial soft tissues, and multiplanar deformities
may all be present in the valgus arthritic knee. A number of classifications
have been reported in order to guide surgical management, and a variety
of surgical strategies have been described with satisfactory clinical
results. Depending on the severity of the deformity, a variety of
TKA implant designs may be appropriate for use. Regardless of an operating surgeon’s preferred surgical strategy,
adherence to a step-wise approach to deformity correction is advised. Cite this article:
Analysis of the morphology of the distal femur, and by extension
of the femoral components in total knee arthroplasty (TKA), has
largely been related to the aspect ratio, which represents the width
of the femur. Little is known about variations in trapezoidicity
(i.e. whether the femur is more rectangular or more trapezoidal).
This study aimed to quantify additional morphological characteristics
of the distal femur and identify anatomical features associated
with higher risks of over- or under-sizing of components in TKA. We analysed the shape of 114 arthritic knees at the time of primary
TKA using the pre-operative CT scans. The aspect ratio and trapezoidicity
ratio were quantified, and the post-operative prosthetic overhang
was calculated. We compared the morphological characteristics with
those of 12 TKA models.Aims
Methods
Total knee arthroplasty (TKA) is a cost effective
and extremely successful operation. As longevity increases, the demand
for primary TKA will continue to rise. The success and survivorship
of TKAs are dependent on the demographics of the patient, surgical
technique and implant-related factors. Currently the risk of failure of a TKA requiring revision surgery
ten years post-operatively is 5%. The most common indications for revision include aseptic loosening
(29.8%), infection (14.8%), and pain (9.5%). Revision surgery poses
considerable clinical burdens on patients and financial burdens
on healthcare systems. We present a current concepts review on the epidemiology of failed
TKAs using data from worldwide National Joint Registries. Cite this article:
Preservation of posterior condylar offset (PCO) has been shown to correlate with improved functional results after primary total knee arthroplasty (TKA). Whether this is also the case for revision TKA, remains unknown. The aim of this study was to assess the independent effect of PCO on early functional outcome after revision TKA. A total of 107 consecutive aseptic revision TKAs were performed by a single surgeon during an eight-year period. The mean age was 69.4 years (39 to 85) and there were 59 female patients and 48 male patients. The Oxford Knee Score (OKS) and Short-form (SF)-12 score were assessed pre-operatively and one year post-operatively. Patient satisfaction was also assessed at one year. Joint line and PCO were assessed radiographically at one year.Objectives
Methods
There are two techniques widely used to determine the rotational
alignment of the components in total knee arthroplasty (TKA); gap
balancing (GB) and measured resection (MR). Which technique is the
best remains controversial. We aimed to investigate this in a systematic
review and meta-analysis. In accordance with the methods of Cochrane, databases were searched
for all randomised controlled trials in the literature between January
1986 and June 2015 comparing radiographic and clinical outcomes
between the use of these two tecniques. Meta-analysis involved the
use of the Revman5.3 software provided by Cochrane collaboration.Aims
Materials and Methods
The aim of this study was to define return to
theatre (RTT) rates for elective hip and knee replacement (HR and
KR), to describe the predictors and to show the variations in risk-adjusted
rates by surgical team and hospital using national English hospital
administrative data. We examined information on 260 206 HRs and 315 249 KRs undertaken
between April 2007 and March 2012. The 90-day RTT rates were 2.1%
for HR and 1.8% for KR. Male gender, obesity, diabetes and several
other comorbidities were associated with higher odds for both index
procedures. For HR, hip resurfacing had half the odds of cement fixation
(OR = 0.58, 95% confidence intervals (CI) 0.47 to 0.71). For KR,
unicondylar KR had half the odds of total replacement (OR = 0.49,
95% CI 0.42 to 0.56), and younger ages had higher odds (OR = 2.23,
95% CI 1.65 to 3.01) for ages <
40 years compared with ages 60
to 69 years). There were more funnel plot outliers at three standard deviations
than would be expected if variation occurred on a random basis. Hierarchical modelling showed that three-quarters of the variation
between surgeons for HR and over half the variation between surgeons
for KR are not explained by the hospital they operated at or by
available patient factors. We conclude that 90-day RTT rate may
be a useful quality indicator for orthopaedics. Cite this article:
Malrotation of the femoral component can result in post-operative complications in total knee arthroplasty (TKA), including patellar maltracking. Therefore, we used computational simulation to investigate the influence of femoral malrotation on contact stresses on the polyethylene (PE) insert and on the patellar button as well as on the forces on the collateral ligaments. Validated finite element (FE) models, for internal and external malrotations from 0° to 10° with regard to the neutral position, were developed to evaluate the effect of malrotation on the femoral component in TKA. Femoral malrotation in TKA on the knee joint was simulated in walking stance-phase gait and squat loading conditions.Objectives
Materials and Methods
To compare the gait of unicompartmental knee arthroplasty (UKA)
and total knee arthroplasty (TKA) patients with healthy controls,
using a machine-learning approach. 145 participants (121 healthy controls, 12 patients with cruciate-retaining
TKA, and 12 with mobile-bearing medial UKA) were recruited. The
TKA and UKA patients were a minimum of 12 months post-operative,
and matched for pattern and severity of arthrosis, age, and body
mass index. Participants walked on an instrumented treadmill until their
maximum walking speed was reached. Temporospatial gait parameters,
and vertical ground reaction force data, were captured at each speed.
Oxford knee scores (OKS) were also collected. An ensemble of trees
algorithm was used to analyse the data: 27 gait variables were used
to train classification trees for each speed, with a binary output
prediction of whether these variables were derived from a UKA or
TKA patient. Healthy control gait data was then tested by the decision
trees at each speed and a final classification (UKA or TKA) reached
for each subject in a majority voting manner over all gait cycles
and speeds. Top walking speed was also recorded.Aims
Patients and Methods
The aim of this consensus was to develop a definition of post-operative
fibrosis of the knee. An international panel of experts took part in a formal consensus
process composed of a discussion phase and three Delphi rounds.Aims
Patients and Methods
The interest in unicompartmental knee arthroplasty (UKA) for
medial osteoarthritis has increased rapidly but the long-term follow-up
of the Oxford UKAs has yet to be analysed in non-designer centres.
We have examined our ten- to 15-year clinical and radiological follow-up
data for the Oxford Phase III UKAs. Between January 1999 and January 2005 a total of 138 consecutive
Oxford Phase III arthroplasties were performed by a single surgeon
in 129 patients for medial compartment osteoarthritis (71 right
and 67 left knees, mean age 72.0 years (47 to 91), mean body mass
index 28.2 (20.7 to 52.2)). Both clinical data and radiographs were
prospectively recorded and obtained at intervals. Of the 129 patients,
32 patients (32 knees) died, ten patients (12 knees) were not able
to take part in the final clinical and radiological assessment due
to physical and mental conditions, but via telephone interview it
was confirmed that none of these ten patients (12 knees) had a revision
of the knee arthroplasty. One patient (two knees) was lost to follow-up.Aims
Patients and Methods
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
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
We have reviewed the literature to establish the role of lateral retinacular release in the management of disorders of the extensor apparatus of the knee. The scientific evidence for intervention is explored and reports on outcome are discussed.
We present a prospective review of the two-year functional outcome of 37 Avon patellofemoral joint replacements carried out in 29 patients with a mean age of 66 years (30 to 82) between October 2002 and March 2007. No patients were lost to follow-up. This is the first independent assessment of this prosthesis using both subjective and objective analysis of outcome. At two years the median Oxford knee score was 39 (interquartile range 32 to 44), the median American Knee Society objective score was 95 (interquartile range 90 to 100), the median American Knee Society functional score was 85 (interquartile range 60 to 100), and the median Melbourne Knee score was 28 (interquartile range 21 to 30). Two patients underwent further surgery. Only one patient reported an unsatisfactory outcome. We conclude that the promising early results observed by the designing centre are reproducible and provide further support for the role of patellofemoral joint replacement.
Many radiographic techniques have been described for measuring patellar height. They can be divided into two groups: those that relate the position of the patella to the femur (direct) and those that relate it to the tibia (indirect). This article looks at the methods that have been described, the logic behind their conception and the critical analyses that have been performed to test them.
