Three-Dimensional Printed Models in Pre-Operative Planning of Complex Primary and Revision Total Knee Arthroplasty

Three-dimensional (3D) printing was introduced firstly for industrial use, but it gained popularity in different medical fields, including orthopedic surgeries. Particularly, 3D-printed models have been used in the pre-operative planning for spine surgery, oncology, acetabular fracture treatment and complex primary total hip arthroplasty (THA) or revision THA. In knee surgery, some authors described good accuracy with 3D-printed wedge for Opening Wedge High Tibial Osteotomy (OWHTO), but there are no studies describing its application in Total Knee Arthroplasty (TKA). In both primary and revision TKA, a 3D-printed model may be useful to better evaluate knee morphology and deformity, implants, bone losses and the compatibility between different components used. Furthermore, some companies provide a bone thickness evaluation, which may be useful to identify zones at risk of intra-operative fracture, especially in those cases in which a cone or sleeve must be used. The first aim of this manuscript was to evaluate possible application of 3D-printed model in pre-operative planning of both complex primary and revision TKA, compared to standard planning. Two clinical cases will also be described to show how these models can be used for planning purposes

Treatment of Bone Losses in Revision Total Hip and Knee Arthroplasty Using Trabecular Metal: Current Literature

Revision Total Knee or Hip Arthroplasty is challenging procedures for surgeons usually characterized by bone loss. There are different options available to treat those bone losses. However, there is still a concern on the stability of bone-implant interface, which is mandatory to achieve good long-term results in prosthetic implants. Recently, porous tantalum has been introduced, with the aim of improving the bone-implant interface fixation and implant primary stability. Different solutions for the treatment of bone defects in both revision Total Knee and Hip Arthroplasty have been proposed. In revision Total Hip Arthroplasty (THA) tantalum shells can be used to treat Paprosky type III defects also, because of their mechanical properties. Similarly, trabecular metal has been proposed in revision Total Knee Arthroplasty (TKA), being considered a viable option to treat severe type 2 or 3 defects. The aim of this paper is to review the mechanical properties and characteristics of tantalum. Furthermore, we will discuss its role in treating bone defects in both revision THA and TKA, as well as the outcome reported in literature

Use of tranexamic acid in total knee arthroplasty

PURPOSE: different strategies have been developed to reduce blood loss in total knee arthroplasty (TKA). The efficacy of both systemic and local tranexamic acid (TXA) administration is demonstrated in the literature. The aim of the present study was to compare the efficacy of systemic, local and combined (systemic + local) administration of TXA in reducing blood loss after TKA. METHODS: we enrolled all patients submitted to a primary TKA in our department between November 2014 and August 2015. They were divided into three groups corresponding to the method of TXA administration used: intravenous (IV), intra-articular (IA), and a combination of the two. Demographic data, as well as preoperative hemoglobin and platelet levels, were collected. The primary outcome was the maximum hemoglobin loss, while the secondary outcomes were the amount of blood in the drain (cc/hour) and the rate of transfusions; postoperative pain was also assessed. Student’s t-test or a χ(2) test was used to evaluate between-group differences, using p<0.05 as the cut-off for statistically significant differences. RESULTS: the sample comprised 34 patients: IV, 10 cases; IA, 15 cases, and combined (IV + IA), 9 cases. The average age of the patients was 71.1±6.4 years. No significant differences in the outcome measures were found between the groups, with the exception of a significantly lower maximum hemoglobin loss in the combined versus the IV group (p=0.02). There were no differences between the groups in the amount of blood in the drain or the rate of transfusions. CONCLUSIONS: the data from this preliminary study, as well as data from the literature, confirm that TXA administration is safe and effective in reducing total blood loss in TKA, and no administration protocol seems to be superior to the others. LEVEL OF EVIDENCE: Level II, prospective comparative study

Total knee arthroplasty and infection: how surgeons can reduce the risks

Total joint arthroplasty (TJA) is one of the most common orthopaedic procedures. Nevertheless, several complications can lead to implant failure. Peri-prosthetic joint infections (PJI) certainly represent a significant challenge in TJA, constituting a major cause of prosthetic revision. The surgeon may have an important role in reducing the PJI rate by limiting the impact of significant risk factors associated to either the patient, the operative environment or the post-operative care. In the pre-operative period, several preventive measures may be adopted to manage reversible medical comorbidities. Other recognised pre-operative risk factors are urinary tract infections, intra-articular corticosteroid injections and nasal colonisation with Staphylococcus (S.) aureus, particularly the methicillin-resistant strain (MRSA). In the intra-operative setting, protective measures for PJI include antibiotic prophylaxis, surgical-site antisepsis and use of pre-admission chlorhexidine washing and pulsed lavage during surgery. In this setting, the use of plastic adhesive drapes and sterile stockinette, as well as using personal protection systems, do not clearly reduce the risk of infection. On the contrary, using sterile theatre light handles and splash basins as well as an increased traffic in the operating room are all associated with an increased risk for PJI. In the post-operative period, other infections causing transient bacteraemia, blood transfusion and poor wound care are considered as risk factors for PJI. Cite this article: Ratto N, Arrigoni C, Rosso F, Bruzzone M, Dettoni F, Bonasia DE, Rossi R. Total knee arthroplasty and infection: how surgeons can reduce the risks. EFORT Open Rev 2016;1: 339-344 DOI: 10.1302/2058-5241.1.000032

High tibial osteotomy in varus knees: indications and limits

Opening wedge high tibial osteotomy (OWHTO) is a surgical procedure that aims to correct the weight-bearing axis of the knee, moving the loads laterally from the medial compartment. Conventional indications for OWHTO are medial compartment osteoarthritis and varus malalignment of the knee; recently OWHTO has been used successfully in the treatment of double and triple varus. OWHTO, in contrast to closing wedge high tibial osteotomy, does not require fibular osteotomy or peroneal nerve dissection, or lead to disruption of the proximal tibiofibular joint and bone stock loss. For these reasons, interest in this procedure has grown in recent years. The aim of this study is to review the literature on OWHTO, considering indications and prognostic factors (body mass index, grade of osteoarthritis, instability, range of movement and age), outcomes at mid-term follow-up, and limits of the procedure (slope modifications, patellar height changes and difficulties in conversion to a total knee arthroplasty)