Obtaining a balanced flexion gap with correct
femoral component rotation is one of the prerequisites for a successful
outcome after total knee replacement (TKR). Different techniques
for achieving this have been described. In this study we prospectively
compared gap-balancing versus measured resection
in terms of reliability and accuracy for
Aims. The aim of this study was to conduct the largest low contact stress (LCS) retrieval study to elucidate the failure mechanisms of the Porocoat and Duofix
Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are common orthopaedic procedures requiring postoperative radiographs to confirm implant positioning and identify complications. Artificial intelligence (AI)-based image analysis has the potential to automate this postoperative surveillance. The aim of this study was to prepare a scoping review to investigate how AI is being used in the analysis of radiographs following THA and TKA, and how accurate these tools are. The Embase, MEDLINE, and PubMed libraries were systematically searched to identify relevant articles. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews and Arksey and O’Malley framework were followed. Study quality was assessed using a modified Methodological Index for Non-Randomized Studies tool. AI performance was reported using either the area under the curve (AUC) or accuracy.Aims
Methods
We followed 138 patients (145 hips) who had had uncemented total hip arthroplasty using the Taperloc
Objectives. Initial stability of tibial trays is crucial for long-term success of total knee arthroplasty (TKA) in both primary and revision settings. Rotating platform (RP) designs reduce torque transfer at the tibiofemoral interface. We asked if this reduced torque transfer in RP designs resulted in subsequently reduced micromotion at the cemented fixation interface between the prosthesis component and the adjacent bone. Methods. Composite tibias were implanted with fixed and RP primary and revision tibial trays and biomechanically tested under up to 2.5 kN of axial compression and 10° of external
Currently, the US Center for Medicaid and Medicare Services (CMS) has been testing bundled payments for revision total joint arthroplasty (TJA) through the Bundled Payment for Care Improvement (BPCI) programme. Under the BPCI, bundled payments for revision TJAs are defined on the basis of diagnosis-related groups (DRGs). However, these DRG-based bundled payment models may not be adequate to account appropriately for the varying case-complexity seen in revision TJAs. The 2008-2014 Medicare 5% Standard Analytical Files (SAF5) were used to identify patients undergoing revision TJA under DRG codes 466, 467, or 468. Generalized linear regression models were built to assess the independent marginal cost-impact of patient, procedural, and geographic characteristics on 90-day costs.Aims
Methods
Between 1971 and 1991 we performed Charnley low-friction arthroplasty (LFA) on 116 patients (186 hips) with juvenile chronic arthritis (JCA). We have now carried out a survival study, taking endpoints as revision, death or the end of the year 1993. Overall survival was 91.9% at ten years and 83.0% at 15 years. That of the
The aim of this study was to give estimates of the incidence of component incompatibility in hip and knee arthroplasty and to test the effect of an online, real-time compatibility check. Intraoperative barcode registration of arthroplasty implants was introduced in Denmark in 2013. We developed a compatibility database and, from May 2017, real-time compatibility checking was implemented and became part of the registration. We defined four classes of component incompatibility: A-I, A-II, B-I, and B-II, depending on an assessment of the level of risk to the patient (A/B), and on whether incompatibility was knowingly accepted (I/II).Aims
Materials and Methods
We have reviewed retrospectively 68 revisions of the
This study aimed to develop a virtual clinic for the purpose of reducing face-to-face orthopaedic consultations. Anonymized experts (hip and knee arthroplasty patients, surgeons, physiotherapists, radiologists, and arthroplasty practitioners) gave feedback via a Delphi Consensus Technique. This consisted of an iterative sequence of online surveys, during which virtual documents, made up of a patient-reported questionnaire, standardized radiology report, and decision-guiding algorithm, were modified until consensus was achieved. We tested the patient-reported questionnaire on seven patients in orthopaedic clinics using a ‘think-aloud’ process to capture difficulties with its completion.Aims
Patients and Methods
Aims
Patients and Methods
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:
Positive cultures are not uncommon in cases of revision total
knee and hip arthroplasty (TKA and THA) for presumed aseptic causes.
The purpose of this study was to assess the incidence of positive
intra-operative cultures in presumed aseptic revision of TKA and
THA, and to determine whether the presence of intra-operative positive cultures
results in inferior survival in such cases. A retrospective cohort study was assembled with 679 patients
undergoing revision knee (340 cases) or hip arthroplasty (339 cases)
for presumed aseptic causes. For all patients three or more separate
intra-operative cultures were obtained. Patients were diagnosed
with a previously unsuspected prosthetic joint infection (PJI) if two
or more cultures were positive with the same organism. Records were
reviewed for demographic details, pre-operative laboratory results
and culture results. The primary outcome measure was infection-free
implant survival at two years.Aims
Patients and Methods
We investigated changes in the axial alignment of the ipsilateral
hip and knee after total hip arthroplasty (THA). We reviewed 152 patients undergoing primary THA (163 hips; 22
hips in men, 141 hips in women) without a pre-operative flexion
contracture. The mean age was 64 years (30 to 88). The diagnosis
was osteoarthritis (OA) in 151 hips (primary in 18 hips, and secondary
to dysplasia in 133) and non-OA in 12 hips. A posterolateral approach
with repair of the external rotators was used in 134 hips and an
anterior approach in 29 hips. We measured changes in leg length
and offset on radiographs, and femoral anteversion, internal rotation
of the hip and lateral patellar tilt on CT scans, pre- and post-operatively. Aims
Patients and Methods
Collateral ligament release is advocated in total
knee arthroplasty (TKA) to deal with significant coronal plane deformities,
but is also associated with significant disadvantages. We describe steps to avoid release of the collateral (superficial
medial and lateral collateral) ligaments during TKA in severely
deformed knees, while correcting deformity and balancing the knee. Cite this article:
Because posterior cruciate ligament (PCL) resection makes flexion
gaps wider in total knee replacement (TKR), preserving or sacrificing
a PCL affects the gap equivalence; however, there are no criteria
for the PCL resection that consider gap situations of each knee.
This study aims to investigate gap characteristics of knees and
to consider the criteria for PCL resection. The extension and flexion gaps were measured, first with the
PCL preserved and subsequently with the PCL removed (in cases in
which posterior substitute components were selected). The PCL preservation
or sacrifice was solely determined by the gap measurement results,
without considering other functions of the PCL such as ‘roll back.’Objectives
Methods
Computed tomography (CT) plays an important role in evaluating wear and periacetabular osteolysis (PAO) in total hip replacements. One concern with CT is the high radiation exposure since standard pelvic CT provides approximately 3.5 millisieverts (mSv) of radiation exposure, whereas a planar radiographic examination with three projections totals approximately 0.5 mSv. The objective of this study was to evaluate the lowest acceptable radiation dose for dual-energy CT (DECT) images when measuring wear and periacetabular osteolysis in uncemented metal components. A porcine pelvis with bilateral uncemented hip prostheses and with known linear wear and acetabular bone defects was examined in a third-generation multidetector DECT scanner. The examinations were performed with four different radiation levels both with and without iterative reconstruction techniques. From the high and low peak kilo voltage acquisitions, polychrmoatic images were created together with virtual monochromatic images of energies 100 kiloelectron volts (keV) and 150 keV.Objectives
Materials and Methods
The Unified Classification System (UCS) was introduced
because of a growing need to have a standardised universal classification
system of periprosthetic fractures. It combines and simplifies many
existing classification systems, and can be applied to any fracture
around any partial or total joint replacement occurring during or
after operation. Our goal was to assess the inter- and intra-observer
reliability of the UCS in association with knee replacement when
classifying fractures affecting one or more of the femur, tibia
or patella. We used an international panel of ten orthopaedic surgeons with
subspecialty fellowship training and expertise in adult hip and
knee reconstruction (‘experts’) and ten residents of orthopaedic
surgery in the last two years of training (‘pre-experts’). They
each received 15 radiographs for evaluation. After six weeks they
evaluated the same radiographs again but in a different order. The reliability was assessed using the Kappa and weighted Kappa
values. The Kappa values for inter-observer reliability for the experts
and the pre-experts were 0.741 (95% confidence interval (CI) 0.707
to 0.774) and 0.765 (95% CI 0.733 to 0.797), respectively. The weighted
Kappa values for intra-observer reliability for the experts and
pre-experts were 0.898 (95% CI 0.846 to 0.950) and 0.878 (95% CI
0.815 to 0.942) respectively. The UCS has substantial inter-observer reliability and ‘near
perfect’ intra-observer reliability when used for periprosthetic
fractures in association with knee replacement in the hands of experienced
and inexperienced users. Cite this article:
Fungal peri-prosthetic infections of the knee
and hip are rare but likely to result in devastating complications.
In this study we evaluated the results of their management using
a single-stage exchange technique. Between 2001 and 2011, 14 patients
(ten hips, four knees) were treated for a peri-prosthetic fungal
infection. One patient was excluded because revision surgery was
not possible owing to a large acetabular defect. One patient developed
a further infection two months post-operatively and was excluded
from the analysis. Two patients died of unrelated causes. After a mean of seven years (3 to 11) a total of ten patients
were available for follow-up. One patient, undergoing revision replacement
of the hip, had a post-operative dislocation. Another patient, undergoing
revision replacement of the knee, developed a wound infection and
required revision 29 months post-operatively following a peri-prosthetic femoral
fracture. The mean Harris hip score increased to 74 points (63 to 84; p
<
0.02) in those undergoing revision replacement of the hip,
and the mean Hospital for Special Surgery knee score increased to
75 points (70 to 80; p <
0.01) in those undergoing revision replacement
of the knee. A single-stage revision following fungal peri-prosthetic infection
is feasible, with an acceptable rate of a satisfactory outcome. Cite this article:
We reviewed the outcome of 69 uncemented, custom-made,
distal femoral endoprosthetic replacements performed in 69 patients
between 1994 and 2006. There were 31 women and 38 men with a mean
age at implantation of 16.5 years (5 to 37). All procedures were
performed for primary malignant bone tumours of the distal femur.
At a mean follow-up of 124.2 months (4 to 212), 53 patients were
alive, with one patient lost to follow-up. All nine implants (13.0%)
were revised due to aseptic loosening at a mean of 52 months (8
to 91); three implants (4.3%) were revised due to fracture of the
shaft of the prosthesis and three patients (4.3%) had a peri-prosthetic
fracture. Bone remodelling associated with periosteal cortical thinning
adjacent to the uncemented intramedullary stem was seen in 24 patients
but this did not predispose to failure. All aseptically loose implants
in this series were diagnosed to be loose within the first five
years. The results from this study suggest that custom-made uncemented
distal femur replacements have a higher rate of aseptic loosening
compared to published results for this design when used with cemented
fixation. Loosening of uncemented replacements occurs early indicating
that initial fixation of the implant is crucial. Cite this article: