Level III. Prospective study.

I.

Background: The use of electric scooters has increased considerably as they are an accessible means of transportation. The number of injuries from falls and collisions has risen significantly. Therefore, the aim of the study was to describe demographics injury patterns of electric scooter accidents produced over one year. Methods: A prospective observational study of electric scooter- related injuries presented in the emergency room from May 2019 until May 2020. The inclusion criteria was based on the direct cause of injury produced while an electric scooter was in use. Demographic data, the use of a helmet or the lack thereof, accident mechanism, injury time, type of injury produced, and the treatment applied were collected. Results: Over the study period, 397 patients were identified with a total of 422 injuries. The mean age was 30.8 years, with 12.6% of patients being minors. The patients mainly presented in evening hours and in summertime at the emergency department. Of the total injuries seen, 46.9% were fractures. Some 25% of the total cases required surgery. Only 19% of the riders wore a helmet at the time of the accident. Most of the fractures were to the upper limbs (62.6%). There was a greater incidence of radius fractures. Conclusion: Injuries incurred while using electric scooters are an emerging phenomenon, despite existing regulations. In this study, most injuries occurred in young men and were due to falls from the vehicle. Nearly half of those injuries were fractures to the upper limbs. Surprisingly, 50% of the fractures required surgery.

Purpose The presence of allergies has been proposed as a risk factor for worse outcomes in total knee arthroplasty surgery. The aim of this study is to evaluate if the presence of some psychiatric disorders is more frequent in patients who report allergies and if they could be the main cause for the worse outcomes. Methods A prospective study, including patients undergoing a primary total knee arthroplasty, was designed. In the preoperative visit, all the patients completed a questionnaire about the presence of allergies and also psychiatric tests for anxiety (State‐Trait Anxiety Inventory–STAI‐), depression (Remission from Depression Questionnaire–RDQ‐), somatization disorder (Patient Health Questionnaire‐15–PHQ‐15‐), pain catastrophizing syndrome (Pain Catastrophizing Scale–PCS), and personality disorder (Reduced NEO‐Inventory of Five Factors–NEO‐FFI‐). In the preoperative and at 6 months of follow up, the functional results of the surgery were assessed by the WOMAC, the SF‐12, and the KSS scores. Results A total of 209 patients was included: 136 (65%) did not have reported allergies and 73 (35%) did report some allergies. The psychiatric questionnaires showed that the presence of anxiety was more prevalent in the group of patients with reported allergies (STAI‐T: no allergies 24.08 points vs. allergies 19.18 points, p = 0.039). When comparing the functional outcomes at 6 months of follow up, most of the analyzed scores improved less in the group of patients with reported allergies than in the no allergy‐referred group: WOMAC‐total score (34.37 vs. 40.10 points, p = 0.023), WOMAC‐pain score (6.03 vs. 7.50 points, p = 0.018), WOMAC‐function score (22.97 vs. 27.24 points, p = 0.023), KSS‐knee score (25.37 vs. 33.79 points, p = 0.002), and SF‐12 physical score (7.89 vs. 11.15 points, p = 0.046). The significance of the difference in the outcomes scores in this group was lost after adjusting for anxiety (p > 0.05). Conclusion Allergies reported by patients are confirmed as a risk factor for worse results after TKA surgery. The relationship with anxiety disorder seems to explain the association between self‐reported allergies and sub‐optimal outcomes. Level of evidence II.

Bidirectional barbed sutures (BBSs) have recently been investigated in total knee arthroplasty (TKA). The contrasting results from the scarce literature suggest that BBSs are safe, save time and money, and give results comparable to traditional sutures. The purpose of the study is to test the real effect of BBSs on closure time in TKA and assess the functional results as well as the complications related to them. It was a randomized controlled trial. Eighty-five patients undergoing primary TKA were assigned to receive traditional closure with Vicryl (V-group) or with BBSs (Q-group). The exclusion criteria were significant coronal deformity, flexion contracture, or the need for stem and/or augmentation. The closure time for the capsule and that for the subcutaneous layer were registered separately. Intraoperative incidences were recorded. The follow-up was up to 1 month, during which the range of motion (ROM), superficial or deep infection, and wound dehiscence were assessed. There was a significant reduction in the capsule layer (27 seconds; p = 0.02) and global time closure (51 seconds; p = 0.01) in the Q-group. No differences were found in the subcutaneous layer (24 seconds; p = 0.055). There were more intraoperative suture breakages in the Q-group, mainly in the subcutaneous layer (p < 0.001). No differences in terms of dehiscence, infection, and ROM were observed at the 1-month follow-up. BBSs allow for slightly faster wound closure than Vicryl during a TKA. However, the differences observed have minimal clinical repercussions. Moreover, no differences in the infection rate (deep or superficial), dehiscence, or ROM were found.

Therapeutic study: Prospective comparative study, Level II.

Therapeutic study, Level III.

Purpose Anterior knee pain (AKP) is a frequent symptom after a total knee arthroplasty (TKA). Patellar denervation (PD) has been put forth as a technique to reduce this pain; however, its efects have not been assessed in combination with patellar resurfacing. The aim of this study is to evaluate the efect of PD on AKP and functional outcomes after TKA with patellar resurfacing. Methods A prospective study was designed that included patients scheduled for TKA with patellar resurfacing. The 202 recruited patients were randomized into either the PD group or the non-denervation group [mean age 72.7 years (SD 8.2); 119 (70.4%) women and 50 (29.6%) men; average body mass index 31.4 kg/m 2 (SD 4.9)]. Pressure pain threshold (PPT) assessed by pressure algometry (PA), visual analogue scale(VAS), patellofemoral Feller score and the Knee Society Scores (KSS) were recorded preoperatively and at the 1-year follow-up. Results 169 patients were included in data analysis. At the 1-year follow-up, there were mild diferences between denervation and non-denervation group in PPT value (494.4 kPa vs. 552.3 kPa, p = 0.047) and in VAS at stairs (2.9 vs. 1.5, p = 0.003) in favour of the non-denervation group. There was no diference in the improvement between groups in patellofemoral Feller score and KSS, but slightly higher improvement in non-denervation group in PPT (94.1 kPa vs. 160 kPa, p = 0.047), VAS walking (5.3 vs. 6.2, p = 0.041) and VAS at stairs (4.6 vs. 5.7, p = 0.022). Conclusion Patellar denervation does not improve AKP and clinical outcomes in primary TKA with patellar resurfacing compared to patellar replacement without denervation. PD cannot be recommended when patellar replacement is performed in TKA. Level of evidence II.