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<p class="abstract"><strong>Background:</strong> Anterior projection of the femoral condyles is often disregarded as an issue in knee arthroplasty. Overstuffing the patellofemoral joint may limit knee flexion and be a source of patellofemoral complications, thus having an impact in satisfaction rates after total knee arthroplasty (TKA). Our hypothesis is that excessive anterior projection of the femoral condyles as a negative effect in flexion range after TKA, introducing a new concept, the anterior offset index (AOI).</p><p class="abstract"><strong>Methods:</strong> From a group of 99 consecutive patients who underwent TKA using patient specific instrumentation (PSI), we selected the patients with good pre-operative flexion range (above 90º) and a 6-minute walk test (6 MWT) ≥ 0 meters, evaluating the correlation between the AOI and the flexion range. A total of 23 patients were included in the study.<strong></strong></p><p class="abstract"><strong>Results:</strong> A moderate and positive correlation (r=0.488; p=0.018) between AOI and flexion range was found.</p><p class="abstract"><strong>Conclusions:</strong> Our results seem to indicate that the AOI influences postoperative flexion in TKA, in patients with a good pre-operative flexion and good functional outcome. AOI is an important concept to retain when optimizing knee flexion and minimizing patellofemoral complications. However, more studies need to be done in order to clarify the role of all the factors influencing post op flexion after TKA.</p>

ObjectiveTo evaluate the clinical and radiologic results of proximal femoral varus derotational and shortening osteotomy (OVRF) (Port., doesn’t match name) with the use of a locked plate in patients with cerebral palsy, classified by the gross motor functional classification system as class IV or V.MethodsA retrospective study of 42 patients (61 hips) with cerebral palsy, gross motor functional classification system class IV or V, submitted to OVRF. The minimal follow up was 24 months. This study evaluated clinical (age at surgery, gender, Gross Motor Functional Classification System class, anatomical cerebral palsy classification, and motor pattern), pre- and post-operative radiological (neck shaft angle, acetabular index, Reimers migration index and time until bone healing) characteristics, as well as post-operative complications.ResultsMean pre-operative cervicodiaphyseal angle, acetabular index, and Reimers migration index were respectively 121.6°, 22.7°, and 65.4% in uncomplicated cases, and 154.7°, 20.4°, and 81.1% in complicated ones. All parameters were statistically significant difference between pre- and postoperative values (p < 0.05). The patients with postoperative complications had a greater cervicodiaphyseal angle and Reimers migration index (p < 0.0001). There were no differences in clinical characteristics, time of immobilization, or bone healing. Fourteen patients had postoperative complications (33.3%), but only six required surgical treatment.ConclusionThe locked plate is a safe resource, with low complication rates and reproducible technique for OVRF in the cerebral palsy population classified as gross motor functional classification system IV and V. Greater cervicodiaphyseal angles and Reimers migration index are associated with greater chances of postoperative complications, as well as gross motor functional classification system V classification.

Tranexamic acid (TXA) is an antifibrinolytic drug that reduces blood loss in patients that undergo Total knee arthroplasty (TKA). Few studies compare its effect on conventional instrumentation (CI) versus patient-specific instrumentation (PSI). The main objective of this study was to understand analytically how TXA usage in both instrumentations influenced blood loss in TKA differently and see if the differences seen could be explained by the patient's body mass index (BMI) and gender. This nonrandomized retrospective study sample consisted of 688 TKA procedures performed on patients who had symptomatic arthrosis resistant to conservative treatment. Descriptive analysis was used to evaluate blood loss using hemoglobin (Hb) mean values and mean variation (%). The Classification and Regression Tree (CRT) method was applied to understand how the independent variables affected the dependent variable. Comparing patients submitted to the same instrumentation, where some received TXA and others did not, patients that received TXA had lower blood loss. Comparing patients who underwent TKA with different instrumentations and without the use of TXA, it was found that patients who underwent TKA with PSI had lower blood loss than those who underwent TKA with CI. However, when these same instruments were compared again, but associated with the use of TXA, the opposite was true with patients undergoing TKA with PSI showing greater blood loss than patients undergoing TKA with CI. TXA usage in TKA is significantly beneficial in minimizing blood loss and regardless of instrumentation. When using TXA, the lowest blood loss was obtained in patients with higher BMI and submitted to TKA with CI. This is most likely explained by the synergistic antifibrotic effect of TXA with adipokines, such as plasminogen activator inhibitor-1 (PAI-1), found in the femoral bone marrow which is perforated using CI. If, however, TXA wasn't used, the lowest blood loss was obtained in patients submitted to TKA with PSI.