Aims. Day-case knee and hip replacement, in which patients are discharged on the day of surgery, has been gaining popularity during the last two decades, and particularly since the COVID-19 pandemic. This systematic review presents the evidence comparing day-case to inpatient-stay surgery. Methods. A systematic literature search was performed of MEDLINE, Embase, and grey literature databases to include all studies which compare day-case with inpatient knee and hip replacement. Meta-analyses were performed where appropriate using a random effects model. The protocol was registered prospectively (PROSPERO CRD42023392811). Results. A total of 38 studies were included, with a total of 83,888 day-case procedures. The studies were predominantly from the USA and Canada, observational, and with a high risk of bias. Day-case patients were a mean of 2.08 years younger (95% CI 1.05 to 3.12), were more likely to be male (odds ratio (OR) 1.3 (95% CI 1.19 to 1.41)), and had a lower mean BMI and American Society of Anesthesiologists grades compared with inpatients. Overall, day-case surgery was associated with significantly lower odds of readmission (OR 0.83 (95% CI 0.73 to 0.96); p = 0.009), subsequent emergency department attendance (OR 0.62 (95% CI 0.48 to 0.79); p < 0.001), and complications (OR 0.7 (95% CI 0.55 to 0.89) p = 0.004), than inpatient surgery. There were no significant differences in the rates of reoperation or mortality. The overall rate of successful same-day discharge for day-case surgery was 85% (95% CI 81 to 88). Patient-reported outcome measures and cost-effectiveness were either equal or favoured day-case. Conclusion. Within the limitations of the literature, in particular the substantial risk of selection bias, the outcomes following day-case knee and hip replacement appear not to be inferior to those following an inpatient stay. The evidence is more robust for unicompartmental knee replacement (UKR) than for
Aims. During
Aims. Debate remains whether the patella should be resurfaced during
The June 2015 Knee Roundup360 looks at: Cruciate substituting
The aims of this retrospective study were to
compare the mid-term outcomes following revision total knee replacement
(TKR) in 76 patients (81 knees) <
55 years of age with those
of a matched group of primary TKRs based on age, BMI, gender and
comorbid conditions. We report the activity levels, functional scores,
rates of revision and complications. Compared with patients undergoing
primary TKR, those undergoing revision TKR had less improvement
in the mean Knee Society function scores (8.14 (–55 to +60) Young patients undergoing revision TKR should be counselled that
they can expect somewhat less improvement and a higher risk of complications
than occur after primary TKR. Cite this article:
We scanned 25 left knees in healthy human subjects
using MRI. Multiplanar reconstruction software was used to take
measurements of the inferior and posterior facets of the femoral
condyles and the trochlea. A ‘basic circle’ can be defined which, in the sagittal plane,
fits the posterior and inferior facets of the lateral condyle, the
posterior facet of the medial condyle and the floor of the groove
of the trochlea. It also approximately fits both condyles in the
coronal plane (inferior facets) and the axial plane (posterior facets).
The circle fitting the inferior facet of the medial condyle in the
sagittal plane was consistently 35% larger than the other circles
and was termed the ‘medial inferior circle’. There were strong correlations
between the radii of the circles, the relative positions of the
centres of the condyles, the width of the condyles, the total knee
width and skeletal measurements including height. There was poor
correlation between the radii of the circles and the position of
the trochlea relative to the condyles. In summary, the condyles are approximately spherical except for
the inferior facet medially, which has a larger radius in the sagittal
plane. The size and position of the condyles are consistent and
change with the size of the person. However, the position of the
trochlea is variable even though its radius is similar to that of
the condyles. This information has implications for understanding
anterior knee pain and for the design of knee replacements. Cite this article:
The December 2014 Knee Roundup360 looks at: national guidance on arthroplasty thromboprophylaxis is effective; unicompartmental knee replacement has the edge in terms of short-term complications; stiff knees, timing and manipulation; neuropathic pain and total knee replacement; synovial fluid α-defensin and CRP: a new gold standard in joint infection diagnosis?; how to assess anterior knee pain?; where is the evidence? Five new implants under the spotlight; and a fresh look at ACL reconstruction
Instability in flexion after total knee replacement
(TKR) typically occurs as a result of mismatched flexion and extension
gaps. The goals of this study were to identify factors leading to
instability in flexion, the degree of correction, determined radiologically,
required at revision surgery, and the subsequent clinical outcomes.
Between 2000 and 2010, 60 TKRs in 60 patients underwent revision
for instability in flexion associated with well-fixed components.
There were 33 women (55%) and 27 men (45%); their mean age was 65
years (43 to 82). Radiological measurements and the Knee Society
score (KSS) were used to assess outcome after revision surgery.
The mean follow-up was 3.6 years (2 to 9.8). Decreased condylar
offset (p <
0.001), distalisation of the joint line (p <
0.001)
and increased posterior tibial slope (p <
0.001) contributed
to instability in flexion and required correction at revision to regain
stability. The combined mean correction of posterior condylar offset
and joint line resection was 9.5 mm, and a mean of 5° of posterior
tibial slope was removed. At the most recent follow-up, there was
a significant improvement in the mean KSS for the knee and function
(both p <
0.001), no patient reported instability and no patient
underwent further surgery for instability. The following step-wise approach is recommended: reduction of
tibial slope, correction of malalignment, and improvement of condylar
offset. Additional joint line elevation is needed if the above steps
do not equalise the flexion and extension gaps. Cite this article:
A retrospective review was performed of patients
undergoing primary cementless
The aim of this study was to find anatomical
landmarks for rotational alignment of the tibial component in total knee
replacement (TKR) in a CT-based study. Pre-operative CT scanning
was performed on 94 South Korean patients (nine men, 85 women, 188
knees) with osteoarthritis of the knee joint prior to TKR. The tibial
anteroposterior (AP) axis was defined as a line perpendicular to
the femoral surgical transepicondylar axis and passing through the centre
of the posterior cruciate ligament (PCL). The angles between the
defined tibial AP axis and anatomical landmarks at various levels
of the tibia were measured. The mean values of the angles between
the defined tibial AP axis and the line connecting the anterior
border of the proximal third of the tibia to the centre of the PCL
was -0.2° (-17 to 14.1, Cite this article:
A national, multi-centre study was designed in
which a questionnaire quantifying the degree of patient satisfaction
and residual symptoms in patients following total knee replacement
(TKR) was administered by an independent, blinded third party survey
centre. A total of 90% of patients reported satisfaction with the
overall functioning of their knee, but 66% felt their knee to be
‘normal’, with the reported incidence of residual symptoms and functional
problems ranging from 33% to 54%. Female patients and patients from
low-income households had increased odds of reporting dissatisfaction.
Neither the use of contemporary implant designs (gender-specific,
high-flex, rotating platform) or custom cutting guides (CCG) with
a neutral mechanical axis target improved patient-perceived outcomes.
However, use of a CCG to perform a so-called kinematically aligned
TKR showed a trend towards more patients reporting their knee to
feel ‘normal’ when compared with a so called mechanically aligned
TKR This data shows a degree of dissatisfaction and residual symptoms
following TKR, and that several recent modifications in implant
design and surgical technique have not improved the current situation. Cite this article:
Although the vast majority of patients that undergo
total knee replacement have satisfactory outcomes with a generally
low complication rate, occasionally a patient will be encountered
that has had multiple failed surgeries, and now reaches a crossroad
as to whether limb salvage will be acceptable or not. Cite this article:
The aim of this study was to examine the functional
outcome at ten years following lateral closing wedge high tibial osteotomy
for medial compartment osteoarthritis of the knee and to define
pre-operative predictors of survival and determinants of functional
outcome. 164 consecutive patients underwent high tibial osteotomy between
2000 and 2002. A total of 100 patients (100 knees) met the inclusion
criteria and 95 were available for review at ten years. Data were
collected prospectively and included patient demographics, surgical
details, long leg alignment radiographs, Western Ontario and McMaster Universities
osteoarthritis index (WOMAC) and Knee Society scores (KSS) pre-operatively
and at five and ten years follow-up. At ten years, 21 patients had been revised at a mean of five
years. Overall Kaplan–Meier survival was 87% (95% confidence interval
(CI) 81 to 94) and 79% (95% CI 71 to 87) at five and ten years,
respectively. When compared with unrevised patients, those who had
been revised had significantly lower mean pre-operative WOMAC Scores
(47 (21 to 85) This study has shown that improved survival is associated with
age <
55 years, pre-operative WOMAC scores >
45 and, a BMI <
30. In patients over 55 years of age with adequate pre-operative
functional scores, survival can be good and functional outcomes
can be significantly better than their younger counterparts. We
recommend the routine use of pre-operative functional outcome scores
to guide decision-making when considering suitability for high tibial osteotomy. Cite this article:
There are many reasons why a total knee replacement
(TKR) may fail and qualify for revision. Successful revision surgery
depends as much on accurate assessment of the problem TKR as it
does on revision implant design and surgical technique. Specific
modes of failure require specific surgical solutions. Causes of
failure are often presented as a list or catalogue, without a system
or process for making a decision. In addition, strict definitions
and consensus on modes of failure are lacking in published series
and registry data. How we approach the problem TKR is an essential
but neglected aspect of understanding knee replacement surgery.
It must be carried out systematically, comprehensively and efficiently.
Eight modes of failure are described: 1) sepsis; 2) extensor discontinuity;
3) stiffness; 4) tibial- femoral instability; 5) patellar tracking;
6) aseptic loosening and osteolysis; 7) periprosthetic fracture
and 8) component breakage. A ninth ‘category’, unexplained pain
is an indication for further investigation but not surgery. Cite this article:
The use of hinged implants in primary total knee
replacement (TKR) should be restricted to selected indications and mainly
for elderly patients. Potential indications for a rotating hinge
or pure hinge implant in primary TKR include: collateral ligament
insufficiency, severe varus or valgus deformity (>
20°) with necessary
relevant soft-tissue release, relevant bone loss including insertions
of collateral ligaments, gross flexion-extension gap imbalance,
ankylosis, or hyperlaxity. Although data reported in the literature
are inconsistent, clinical results depend on implant design, proper
technical use, and adequate indications. We present our experience
with a specific implant type that we have used for over 30 years
and which has given our elderly patients good mid-term results.
Because revision of implants with long cemented stems can be very
challenging, an effort should be made in the future to use shorter stems
in modular versions of hinged implants. Cite this article:
The relationship between post-operative bone
density and subsequent failure of
Patellofemoral complications are common after
total knee replacement (TKR). Leaving the patellar unsurfaced after
TKR may lead to complications such as anterior knee pain, and re-operation
to surface it. Complications after patellar resurfacing include
patellar fracture, aseptic loosening, patellar instability, polyethylene
wear, patellar clunk and osteonecrosis. Historically, patellar complications
account for one of the larger proportions of causes of failure in
TKR, however, with contemporary implant designs, complication rates
have decreased. Most remaining failures relate to patellofemoral
tracking. Understanding the causes of patellofemoral maltracking
is essential to prevent these complications as well as manage them
when they occur. Cite this article: