Periprosthetic joint infection (PJI) is a devastating complication following total knee arthroplasty (TKA). Two-stage revision has traditionally been considered the gold standard of treatment for established infection, but increasing evidence is emerging in support of one-stage exchange for selected patients. The objective of this study was to determine the outcomes of single-stage revision TKA for PJI, with mid-term follow-up. A total of 84 patients, with a mean age of 68 years (36 to 92), underwent single-stage revision TKA for confirmed PJI at a single institution between 2006 and 2016. In all, 37 patients (44%) were treated for an infected primary TKA, while the majority presented with infected revisions: 31 had undergone one previous revision (36.9%) and 16 had multiple prior revisions (19.1%). Contraindications to single-stage exchange included systemic sepsis, extensive bone or soft-tissue loss, extensor mechanism failure, or if primary wound closure was unlikely to be achievable. Patients were not excluded for culture-negative PJI or the presence of a sinus.Aims
Methods
A comprehensive classification for coronal lower limb alignment with predictive capabilities for knee balance would be beneficial in total knee arthroplasty (TKA). This paper describes the Coronal Plane Alignment of the Knee (CPAK) classification and examines its utility in preoperative soft tissue balance prediction, comparing kinematic alignment (KA) to mechanical alignment (MA). A radiological analysis of 500 healthy and 500 osteoarthritic (OA) knees was used to assess the applicability of the CPAK classification. CPAK comprises nine phenotypes based on the arithmetic HKA (aHKA) that estimates constitutional limb alignment and joint line obliquity (JLO). Intraoperative balance was compared within each phenotype in a cohort of 138 computer-assisted TKAs randomized to KA or MA. Primary outcomes included descriptive analyses of healthy and OA groups per CPAK type, and comparison of balance at 10° of flexion within each type. Secondary outcomes assessed balance at 45° and 90° and bone recuts required to achieve final knee balance within each CPAK type.Aims
Methods
The aim of this study was to compare robotic arm-assisted bi-unicompartmental knee arthroplasty (bi-UKA) with conventional mechanically aligned total knee arthroplasty (TKA) in order to determine the changes in the anatomy of the knee and alignment of the lower limb following surgery. An analysis of 38 patients who underwent TKA and 32 who underwent bi-UKA was performed as a secondary study from a prospective, single-centre, randomized controlled trial. CT imaging was used to measure coronal, sagittal, and axial alignment of the knee preoperatively and at three months postoperatively to determine changes in anatomy that had occurred as a result of the surgery. The hip-knee-ankle angle (HKAA) was also measured to identify any differences between the two groups.Aims
Methods
An algorithm to determine the constitutional alignment of the lower limb once arthritic deformity has occurred would be of value when undertaking kinematically aligned total knee arthroplasty (TKA). The purpose of this study was to determine if the arithmetic hip-knee-ankle angle (aHKA) algorithm could estimate the constitutional alignment of the lower limb following development of significant arthritis. A matched-pairs radiological study was undertaken comparing the aHKA of an osteoarthritic knee (aHKA-OA) with the mechanical HKA of the contralateral normal knee (mHKA-N). Patients with Grade 3 or 4 Kellgren-Lawrence tibiofemoral osteoarthritis in an arthritic knee undergoing TKA and Grade 0 or 1 osteoarthritis in the contralateral normal knee were included. The aHKA algorithm subtracts the lateral distal femoral angle (LDFA) from the medial proximal tibial angle (MPTA) measured on standing long leg radiographs. The primary outcome was the mean of the paired differences in the aHKA-OA and mHKA-N. Secondary outcomes included comparison of sex-based differences and capacity of the aHKA to determine the constitutional alignment based on degree of deformity.Aims
Methods
It is unknown whether kinematic alignment (KA) objectively improves knee balance in total knee arthroplasty (TKA), despite this being the biomechanical rationale for its use. This study aimed to determine whether restoring the constitutional alignment using a restrictive KA protocol resulted in better quantitative knee balance than mechanical alignment (MA). We conducted a randomized superiority trial comparing patients undergoing TKA assigned to KA within a restrictive safe zone or MA. Optimal knee balance was defined as an intercompartmental pressure difference (ICPD) of 15 psi or less using a pressure sensor. The primary endpoint was the mean intraoperative ICPD at 10° of flexion prior to knee balancing. Secondary outcomes included balance at 45° and 90°, requirements for balancing procedures, and presence of tibiofemoral lift-off.Aims
Methods
Between 15% and 20% of patients remain dissatisfied following total knee arthroplasty (TKA). The SAIPH knee system (MatOrtho, Surrey, United Kingdom) is a medial ball and socket TKA that has been designed to replicate native knee kinematics in order to maximize the range of movement, stability, and function. This system is being progressively introduced in a stepwise fashion, with this study reporting the mid-term clinical and radiological outcomes. A retrospective review was undertaken of the first 100 consecutive patients with five-year follow-up following SAIPH TKA performed by the senior authors. The data that were collected included the demographics of the patients, clinical findings, the rate of intraoperative ligamentous release, patient-reported outcome measures (PROMS), radiological assessment, complications, and all-cause revision. Revision data were cross-checked with a national registry.Aims
Patients and Methods
Periprosthetic joinTt infection (PJI) remains an uncommon, yet devastating complication of total hip arthroplasty (THA) and total knee arthroplasty (TKA). Debridement with antibiotics and implant retention (DAIR) provides an alternative to staged revision. Chronic infection is considered to be a contraindication to DAIR, however, outcomes stratified by chronicity have not been documented. We performed a retrospective review of all DAIR cases performed at our institution between 2008–2015. Timeframe to treatment was categorized as acute (< 6 weeks since surgery), chronic (>6 weeks since surgery) or acute hematogenous (previously well-functioning prosthesis). Treatment failure was defined as reoperation during the first 90-days following DAIR. Univariate analysis (Mann-Whitney U and Chi-square; p<0.05) and generalized estimating equations (GEE) were used with multiple comparison adjustment by Tukey-Kramer method (α = 0.05).Introduction
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 aim of this to study was to compare the previously unreported
long-term survival outcome of the Oxford medial unicompartmental
knee arthroplasty (UKA) performed by trainee surgeons and consultants. We therefore identified a previously unreported cohort of 1084
knees in 947 patients who had a UKA inserted for anteromedial knee
arthritis by consultants and surgeons in training, at a tertiary
arthroplasty centre and performed survival analysis on the group
with revision as the endpoint.Aims
Patients 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
Osteochondritis Dissecans (OCD) is a condition
for which the aetiology remains unknown. It affects subchondral bone
and secondarily its overlying cartilage and is mostly found in the
knee. It can occur in adults, but is generally identified when growth
remains, when it is referred to as juvenile OCD. As the condition
progresses, the affected subchondral bone separates from adjacent
healthy bone, and can lead to demarcation and separation of its associated
articular cartilage. Any symptoms which arise relate to the stage
of the disease. Early disease without separation of the lesion results
in pain. Separation of the lesion leads to mechanical symptoms and
swelling and, in advanced cases, the formation of loose bodies. Early identification of OCD is essential as untreated OCD can
lead to the premature degeneration of the joint, whereas appropriate
treatment can halt the disease process and lead to healing. Establishing
the stability of the lesion is a key part of providing the correct
treatment. Stable lesions, particularly in juvenile patients, have
greater propensity to heal with non-surgical treatment, whereas
unstable or displaced lesions usually require surgical management. This article discusses the aetiology, clinical presentation and
prognosis of OCD in the knee. It presents an algorithm for treatment,
which aims to promote healing of native hyaline cartilage and to
ensure joint congruity. Take home message: Although there is no clear consensus as to
the best treatment of OCD, every attempt should be made to retain
the osteochondral fragment when possible as, with a careful surgical
technique, there is potential for healing even in chronic lesions Cite this article:
In arthritis of the varus knee, a high tibial
osteotomy (HTO) redistributes load from the diseased medial compartment
to the unaffected lateral compartment. We report the outcome of 36 patients (33 men and three women)
with 42 varus, arthritic knees who underwent HTO and dynamic correction
using a Garches external fixator until they felt that normal alignment
had been restored. The mean age of the patients was 54.11 years
(34 to 68). Normal alignment was achieved at a mean 5.5 weeks (3
to 10) post-operatively. Radiographs, gait analysis and visual analogue
scores for pain were measured pre- and post-operatively, at one
year and at medium-term follow-up (mean six years; 2 to 10). Failure
was defined as conversion to knee arthroplasty. Pre-operative gait analysis divided the 42 knees into two equal
groups with high (17 patients) or low (19 patients) adductor moments.
After correction, a statistically significant (p <
0.001, At final follow-up, after a mean of 15.9 years (12 to 20), there
was a survivorship of 59% (95% CI 59.6 to 68.9) irrespective of
adductor moment group, with a mean time to conversion to knee arthroplasty
of 9.5 years (3 to 18; 95% confidence interval ± 2.5). HTO remains a useful option in the medium-term for the treatment
of medial compartment osteoarthritis of the knee but does not last
in the long-term. Cite this article:
Revision knee arthroplasty presents a number
of challenges, not least of which is obtaining solid primary fixation
of implants into host bone. Three anatomical zones exist within
both femur and tibia which can be used to support revision implants.
These consist of the joint surface or epiphysis, the metaphysis
and the diaphysis. The methods by which fixation in each zone can
be obtained are discussed. The authors suggest that solid fixation
should be obtained in at least two of the three zones and emphasise
the importance of pre-operative planning and implant selection. Cite this article:
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:
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:
Satisfactory primary wound healing following
total joint replacement is essential. Wound healing problems can
have devastating consequences for patients. Assessment of their healing
capacity is useful in predicting complications. Local factors that
influence wound healing include multiple previous incisions, extensive
scarring, lymphoedema, and poor vascular perfusion. Systemic factors
include diabetes mellitus, inflammatory arthropathy, renal or liver
disease, immune compromise, corticosteroid therapy, smoking, and
poor nutrition. Modifications in the surgical technique are necessary
in selected cases to minimise potential wound complications. Prompt
and systematic intervention is necessary to address any wound healing
problems to reduce the risks of infection and other potential complications. Cite this article:
Most problems encountered in complex revision
total knee arthroplasty can be managed with the wide range of implant
systems currently available. Modular metaphyseal sleeves, metallic
augments and cones provide stability even with significant bone
loss. Hinged designs substitute for significant ligamentous deficiencies.
Catastrophic failure that precludes successful reconstruction can
be encountered. The alternatives to arthroplasty in such drastic
situations include knee arthrodesis, resection arthroplasty and
amputation. The relative indications for the selection of these
alternatives are recurrent deep infection, immunocompromised host,
and extensive non-reconstructible bone or soft-tissue defects.
The purpose of this study was to determine the accuracy of MRI scan for the detection of meniscal pathology in our unit. There are published data which show that both sensitivity and specificity can approach 90% when compared to arthroscopic findings. We retrospectively analysed a single surgeon series of 240 scopes for all indications The arthroscopic reports included an outline diagram of the meniscus upon which the surgeon recorded operative findings. 112 of these patients had also had recent MRI. We looked at whether the MRI report showed a tear, and this was graded Y/N. The arthroscopic report was graded for tear: Y/N. 66 patients had a positive scan. 64 of these were found to have a tear at surgery. 37 scans were reported as “no tear”, of which 4 were found to have a tear at surgery. Nine scans were not easy to classify as they were descriptive. In our series of 112 knees, MRI was 90.5% sensitive, 89.5% specific and 90.1% accurate. When a definite diagnosis of “tear”, or “no tear” was made at scan, there were two false positives and four false negatives. False positives may be unnecessarily exposed to the risks of surgery. Patients with negative scans had a mean delay to surgery of 33 weeks compared to 18 weeks for patients with positive scans. False negatives may wait longer for their surgery. Two of the false negative scans clearly showed meniscus tears which were missed by the reporting radiographer. In our series the scan itself was more accurate than the reporting. It is important to have an experienced musculoskeletal radiologist to minimise the number of missed tears. It is also important for surgeon to check the scan as well as the report.
Recent advancements in optical navigated TKA have shown improved overall limb alignment, implant placement and reduced outliers compared to conventional TKA. This study represents the first RCT comparing EM navigation and conventional TKA. 3D alignment was analysed from CT scans. Clinical scores (Oxford Knee Score (OKS) and American Knee Society Score (AKSS)) were recorded at pre-op, 3 and 12 months post-op. Data presented includes 180 patients (n=90 per group) at 3 months and 140 (n=70 per group) at 12 months. The groups had similar mean mechanical axis alignments (EM 0.31° valgus; conventional 0.15° valgus). Mechanical axis alignment however was improved in the EM group with 92% within +/−3° of neutral compared to 84% of the conventional group (p=0.90). The EM group showed improved coronal and sagittal femoral alignment and improved coronal, sagittal and rotational tibial alignment, which was significant for sagittal femoral alignment (p=0.04). The OKS and AKSS scores were significantly better for the EM group at 3 months post-op (OKS p=0.02, AKSS p=0.04), but there was no difference between groups at 12 months. The mean pre-op range of motion (ROM) for both groups was 105°. This decreased at 3 months to 102° in the EM group and 99° in the conventional group, but there was a significant improvement by 12 months: EM=113° (p=0.012) and conventional=112° (p=0.026). ROM was statistically similar between groups at all assessment phases. Knee alignment was better restored following EM navigated TKA relative to conventional TKA, but the difference was not significant. The EM group showed greater clinical improvements at early follow-up; however this difference was not sustained at 12 months. ROM was seen to decrease at 3 months but then significantly improve by 12 month post-op. Proving cost-effectiveness for navigation systems in TKA remains a challenge.
To establish the reliability of reporting and recording revision hip and knee arthroplasties by comparing data in the National Joint Registry (NJR), Hospital Episode Statistics (HES) and our local theatre records. The paper theatre registers for all orthopaedic theatres in the Royal Derby Hospitals NHS Trust were examined for details of revision hip and knee replacements carried out in 2007 and 2008. This was then cross-checked and merged with the local electronic theatre data to obtain a definitive local record of all revision hip and knee arthroplasties. Data for the same period was requested from the NJR and HES and these data were checked against our definitive local record for discrepancies. The HES codes used were the same codes used to compile the recent NJR annual reports.Purpose
Methods
