Advanced 3D imaging and CT-based navigation have emerged as valuable tools to use in total knee arthroplasty (TKA), for both preoperative planning and the intraoperative execution of different philosophies of alignment. Preoperative planning using CT-based 3D imaging enables more accurate prediction of the size of components, enhancing surgical workflow and optimizing the precision of the positioning of components. Surgeons can assess alignment, osteophytes, and arthritic changes better. These scans provide improved insights into the patellofemoral joint and facilitate tibial sizing and the evaluation of implant-bone contact area in cementless TKA. Preoperative CT imaging is also required for the development of patient-specific instrumentation cutting guides, aiming to reduce intraoperative blood loss and improve the surgical technique in complex cases. Intraoperative CT-based navigation and haptic guidance facilitates precise execution of the preoperative plan, aiming for optimal positioning of the components and accurate alignment, as determined by the surgeon’s philosophy. It also helps reduce iatrogenic injury to the periarticular soft-tissue structures with subsequent reduction in the local and systemic inflammatory response, enhancing early outcomes. Despite the increased costs and radiation exposure associated with CT-based navigation, these many benefits have facilitated the adoption of imaged based robotic surgery into routine practice. Further research on ultra-low-dose CT scans and exploration of the possible translation of the use of 3D imaging into improved clinical outcomes are required to justify its broader implementation. Cite this article:
Higher osteoblastic bone activity is expected in aseptic loosening and painful unicompartmental knee arthroplasty (UKA). However, insights into normal bone activity patterns after medial UKAs are lacking. The aim of this study was to identify the evolution in bone activity pattern in well-functioning medial mobile-bearing UKAs. In total, 34 patients (13 female, 21 male; mean age 62 years (41 to 79); BMI 29.7 kg/m2 (23.6 to 42.1)) with 38 medial Oxford partial UKAs (20 left, 18 right; 19 cementless, 14 cemented, and five hybrid) were prospectively followed with sequential 99mTc-hydroxymethane diphosphonate single photon emission CT (SPECT)/CT preoperatively, and at one and two years postoperatively. Changes in mean osteoblastic activity were investigated using a tracer localization scheme with volumes of interest (VOIs), reported by normalized mean tracer values. A SPECT/CT registration platform additionally explored cortical tracer evolution in zones of interest identified by previous experimental research.Aims
Methods
Single-stage revision total knee arthroplasty (rTKA) is gaining popularity in treating chronic periprosthetic joint infections (PJIs). We have introduced this approach to our clinical practice and sought to evaluate rates of reinfection and re-revision, along with predictors of failure of both single- and two-stage rTKA for chronic PJI. A retrospective comparative cohort study of all rTKAs for chronic PJI between 1 April 2003 and 31 December 2018 was undertaken using prospective databases. Patients with acute infections were excluded; rTKAs were classified as single-stage, stage 1, or stage 2 of two-stage revision. The primary outcome measure was failure to eradicate or recurrent infection. Variables evaluated for failure by regression analysis included age, BMI, American Society of Anesthesiologists grade, infecting organisms, and the presence of a sinus. Patient survivorship was also compared between the groups.Aims
Methods
To determine the trajectories of patient reported pain and functional disability over five years following total hip arthroplasty (THA) or total knee arthroplasty (TKA). A prospective, longitudinal cohort sub-study within the National Joint Registry (NJR) was undertaken. In all, 20,089 patients who underwent primary THA and 22,489 who underwent primary TKA between 2009 and 2010 were sent Oxford Hip Score (OHS) and Oxford Knee Score (OKS) questionnaires at six months, and one, three, and five years postoperatively. OHS and OKS were disaggregated into pain and function subscales. A k-means clustering procedure assigned each patient to a longitudinal trajectory group for pain and function. Ordinal regression was used to predict trajectory group membership using baseline OHS and OKS score, age, BMI, index of multiple deprivation, sex, ethnicity, geographical location, and American Society of Anesthesiologists grade.Aims
Methods
Ultrasound (US)-guided injections are widely used in patients with conditions of the shoulder in order to improve their accuracy. However, the clinical efficacy of US-guided injections compared with blind injections remains controversial. The aim of this study was to compare the accuracy and efficacy of US-guided compared with blind corticosteroid injections into the glenohumeral joint in patients with primary frozen shoulder (FS). Intra-articular corticosteroid injections were administered to 90 patients primary FS, who were randomly assigned to either an US-guided (n = 45) or a blind technique (n = 45), by a shoulder specialist. Immediately after injection, fluoroscopic images were obtained to assess the accuracy of the injection. The outcome was assessed using a visual analogue scale (VAS) for pain, the American Shoulder and Elbow Surgeons (ASES) score, the subjective shoulder value (SSV) and range of movement (ROM) for all patients at the time of presentation and at three, six, and 12 weeks after injection.Aims
Methods
We sought to establish the incidence of
Few studies have compared survivorship of total shoulder arthroplasty (TSA) with hemiarthroplasty (HA). This observational study compared survivorship of TSA with HA while controlling for important covariables and accounting for death as a competing risk. All patients who underwent shoulder arthroplasty in Ontario, Canada between April 2002 and March 2012 were identified using population-based health administrative data. We used the Fine–Gray sub-distribution hazard model to measure the association of arthroplasty type with time to revision surgery (accounting for death as a competing risk) controlling for age, gender, Charlson Comorbidity Index, income quintile, diagnosis, and surgeon factors.Aims
Patients and Methods
Joint-preserving surgery of the hip (JPSH) has evolved considerably
and now includes a number of procedures, including arthroscopy,
surgical dislocation, and redirectional osteotomies of the femur
and acetabulum. There are a number of different factors which lead
to failure of JPSH. Consequently, it is of interest to assess the
various modes of failure in order to continue to identify best practice
and the indications for these procedures. Using a retrospective observational study design, we reviewed
1013 patients who had undergone JPSH by a single surgeon between
2005 and 2015. There were 509 men and 504 women with a mean age
of 39 years (16 to 78). Of the 1013 operations, 783 were arthroscopies,
122 surgical dislocations, and 108 peri-acetabular osteotomies (PAO).
We analysed the overall failure rates and modes of failure. Re-operations
were categorised into four groups: Mode 1 was arthritis progression
or organ failure leading to total hip arthroplasty (THA); Mode 2
was an Incorrect diagnosis/procedure; Mode 3 resulted from malcorrection
of femur (type A), acetabulum (type B), or labrum (type C) and Mode 4
resulted from an unintended consequence of the initial surgical
intervention.Aims
Patients and Methods
The purpose of this study was to evaluate the
change in sagittal tibiotalar alignment after total ankle arthroplasty (TAA)
for osteoarthritis and to investigate factors affecting the restoration
of alignment. This retrospective study included 119 patients (120 ankles) who
underwent three component TAA using the Hintegra prosthesis. A total
of 63 ankles had anterior displacement of the talus before surgery
(group A), 49 had alignment in the normal range (group B), and eight
had posterior displacement of the talus (group C). Ankles in group
A were further sub-divided into those in whom normal alignment was
restored following TAA (41 ankles) and those with persistent displacement
(22 ankles). Radiographic and clinical results were assessed. Pre-operatively, the alignment in group A was significantly more
varus than that in group B, and the posterior slope of the tibial
plafond was greater (p <
0.01 in both cases). The posterior slope
of the tibial component was strongly associated with restoration
of alignment: ankles in which the alignment was restored had significantly
less posterior slope (p <
0.001). An anteriorly translated talus was restored to a normal position
after TAA in most patients. We suggest that surgeons performing
TAA using the Hintegra prosthesis should aim to insert the tibial
component at close to 90° relative to the axis of the tibia, hence
reducing posterior soft-tissue tension and allowing restoration
of normal tibiotalar alignment following surgery. Cite this article:
Louis Pasteur once said that: “Fortune favours
the prepared mind.” As one of the great scientists who contributed
to the fight against infection, he emphasised the importance of
being prepared at all times to recognise infection and deal with
it. Despite the many scientific discoveries and technological advances,
such as the advent of antibiotics and the use of sterile techniques,
infection continues to be a problem that haunts orthopaedic surgeons
and inflicts suffering on patients. The medical community has implemented many practices with the
intention of preventing infection and treating it effectively when
it occurs. Although high-level evidence may support some of these
practices, many are based on little to no scientific foundation.
Thus, around the world, there is great variation in practices for
the prevention and management of periprosthetic joint infection. This paper summaries the instigation, conduct and findings of
a recent International Consensus Meeting on Surgical Site and Periprosthetic
Joint Infection. Cite this article:
We retrospectively compared the outcome after
the treatment of giant cell tumours of bone either with curettage alone
or with adjuvant cementation. Between 1975 and 2008, 330 patients
with a giant cell tumour were treated primarily by intralesional
curettage, with 84 (25%) receiving adjuvant bone cement in the cavity.
The local recurrence rate for curettage alone was 29.7% (73 of 246)
compared with 14.3% (12 of 84) for curettage and cementation (p
= 0.001). On multivariate analysis both the stage of disease and
use of cement were independent significant factors associated with
local recurrence. The use of cement was associated with a higher
risk of the subsequent need for joint replacement. In patients without
local recurrence, 18.1% (13 of 72) of those with cement needed a
subsequent joint replacement compared to 2.3% (4 of 173) of those
without cement (p = 0.001). In patients who developed local recurrence,
75.0% (9 of 12) of those with previous cementation required a joint
replacement, compared with 45.2% (33 of 73) of those without cement
(p = 0.044).
Early failure associated with adverse reactions to metal debris is an emerging problem after hip resurfacing but the exact mechanism is unclear. We analysed our entire series of 660 metal-on-metal resurfacings (Articular Surface Replacement (ASR) and Birmingham Hip Resurfacing (BHR)) and large-bearing ASR total hip replacements, to establish associations with metal debris-related failures. Clinical and radiological outcomes, metal ion levels, explant studies and lymphocyte transformation tests were performed. A total of 17 patients (3.4%) were identified (all ASR bearings) with adverse reactions to metal debris, for which revision was required. This group had significantly smaller components, significantly higher acetabular component anteversion, and significantly higher whole concentrations of blood and joint chromium and cobalt ions than asymptomatic patients did (all p <
0.001). Post-revision lymphocyte transformation tests on this group showed no reactivity to chromium or cobalt ions. Explants from these revisions had greater surface wear than retrievals for uncomplicated fractures. The absence of adverse reactions to metal debris in patients with well-positioned implants usually implies high component wear. Surgeons must consider implant design, expected component size and acetabular component positioning in order to reduce early failures when performing large-bearing metal-on-metal hip resurfacing and replacement.
We examined the reliability of radiological findings in predicting segmental instability in 112 patients (56 men, 56 women) with a mean age of 66.5 years (27 to 84) who had degenerative disease of the lumbar spine. They underwent intra-operative biomechanical evaluation using a new measurement system. Biomechanical instability was defined as a segment with a neutral zone >
2 mm/N. Risk factor analysis to predict instability was performed on radiographs (range of segmental movement, disc height), MRI (Thompson grade, Modic type), and on the axial CT appearance of the facet (type, opening, vacuum and the presence of osteophytes, subchondral erosion, cysts and sclerosis) using multivariate logistic regression analysis with a forward stepwise procedure. The facet type was classified as sagittally orientated, coronally orientated, anisotropic or wrapped. Stepwise multivariate regression analysis revealed that facet opening was the strongest predictor for instability (odds ratio 5.022, p = 0.009) followed by spondylolisthesis, MRI grade and subchondral sclerosis. Forward stepwise multivariate logistic regression indicated that spondylolisthesis, MRI grade, facet opening and subchondral sclerosis of the facet were risk factors. Symptoms evaluated by the Short-Form 36 and visual analogue scale showed that patients with an unstable segment were in significantly more pain than those without. Furthermore, the surgical procedures determined using the intra-operative measurement system were effective, suggesting that segmental instability influences the symptoms of lumbar degenerative disease.
We performed a prospective, randomised controlled trial of unicompartmental knee arthroplasty comparing the performance of the Acrobot system with conventional surgery. A total of 27 patients (28 knees) awaiting unicompartmental knee arthroplasty were randomly allocated to have the operation performed conventionally or with the assistance of the Acrobot. The primary outcome measurement was the angle of tibiofemoral alignment in the coronal plane, measured by CT. Other secondary parameters were evaluated and are reported. All of the Acrobot group had tibiofemoral alignment in the coronal plane within 2° of the planned position, while only 40% of the conventional group achieved this level of accuracy. While the operations took longer, no adverse effects were noted, and there was a trend towards improvement in performance with increasing accuracy based on the Western Ontario and McMaster Universities Osteoarthritis Index and American Knee Society scores at six weeks and three months. The Acrobot device allows the surgeon to reproduce a pre-operative plan more reliably than is possible using conventional techniques which may have clinical advantages.