Despite reduced laxity and instability and improved activity and participation, individuals who have undergone ACL reconstruction are still at high risk for developing knee OA compared with the general population. The strongest predictors of knee OA after ACL reconstruction were obesity and grade 2 or greater chondrosis in the medial compartment. These results may aid in identifying patients at risk for OA after ACL reconstruction.

High tibial osteotomy for the treatment of medial compartment knee osteoarthritis in the active patient demonstrated favorable clinical results and allowed patients to return to sports and recreational activities similar to the preoperative level.

The insertion site characteristics of the AMB and PLB can be evaluated by predefined reconstructions of computed tomography scans. Clinical relevance These results can serve as orientation landmarks for intra- and postoperative radiographic control and fluoroscopic-based navigation.

The purpose of this study was to evaluate the accuracy of alignment after open-wedge high tibial osteotomy and its effect on the clinical outcome. A prospective case series of 56 consecutive patients underwent open-wedge high tibial osteotomy fixed with a TomoFix plate fixator (Synthes, West Chester, Pennsylvania). The correction angle was radiologically determined preoperatively and at 6 months postoperatively. The patients were clinically and radiologically examined preoperatively and at 3, 6, and 36 months postoperatively. The mechanical axis of 50 knees was corrected from an average of 5.7° varus to 1.3° valgus. Forty-three patients had an acceptable correction with Mikulicz line crossing the tibial plateau between 50% to 70% of the tibial plateau width measured from the medial border. Undercorrection (<50%, group II) and over-correction (>70%, group III) were found in 4 and 3 patients, respectively. The mean Lysholm-Gillquist score at 36 months had improved in all groups, with a statistically lower value for group II. Open-wedge high tibial osteotomy results in significant improvement of symptoms and function in all patients in the short term, even with under- and overcorrection of the osteotomy. Undercorrection was associated with a significantly lower clinical outcome in comparison to the accurate correction and overcorrection. Ligamentous laxity or soft tissue slackness of the knee can influence the overall correction after high tibial osteotomy and must be considered in preoperative planning. Patients with a high body mass index had inferior clinical results after open-wedge high tibial osteotomy.

Since the beginning of the coronavirus disease 2019 (COVID-19) pandemic, laboratory testing to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by real-time reverse transcription PCR (RT-qPCR) has played a central role in mitigating the spread of the virus (1). Soon after the viral genome sequences were available, several RT-qPCR assays were developed and made available by World Health Organization (WHO) for public use (https://www.who.int/docs/default-source/coronaviruse/whoinhouseassays.pdf). The primer and probe sequences for these assays were chosen from multiple target genes within the viral genome such as the E gene, RdRp gene, ORF1ab and N gene. Many commercial and laboratory-developed assays were developed for SARS-CoV-2 detection based on these primer and probe sequences. The large-scale sustained person-to-person transmission of SARS-CoV-2 has led to many mutational events, some of which may affect the sensitivity and specificity of available PCR assays (2). Recently, mutations in the E gene (C26340T) and N gene (C29200T) were reported affecting the detection of target genes by two commercial assays in 8 and 1 patients, respectively. Interestingly, both mutations are of C>T type, a common single nucleotide polymorphism (SNP) that may be associated with strong host cell mRNA editing mechanisms known as APOBEC cytidine deaminase (3, 4). Another study found a G to U substitution in position 29140 that affected the sensitivity of detection of N gene-based assays (5). Here we report a novel N gene mutation (C29200A) seen in 3 patients, which affected the detection of SARS-CoV-2 N gene by a commercial assay.