During the last 15 years, techniques for surgical repair of the medial meniscal posterior root tears (MPRT) have been developed to restore joint biomechanics and joint contact pressures, to prevent the joint from early osteoarthritis. Trans-tibial pull-out repair is one of the most common procedures for meniscal root repair . The transtibial tunnel drilling releases growth factors and progenitor cells from bone marrow and may improve the healing process . Moreover, previous studies [5, 8] reported significant improvement in clinical and radiographic outcomes. A slight modification of the trans-tibial pull-out technique has recently been introduced, called the loop-post construct technique, for meniscal root repair . In the present study, the one-year functional outcomes of this technique showed significant improvement in Lysholm knee scoring items. Admittedly, without a control group utilizing a standard trans-tibial pull-out technique, it seems inappropriate to conclude anything on the clinical advantage of this modified technique.
Included patients were mostly females at their mid-fifties. Patients with a stable knee and no sign of severe osteoarthritis or major malalignment were scheduled for surgical repair of the MPRT. This demographic pattern and surgical indications are in consistency with previous reports [3, 11]. Conversion to total knee arthroplasty and the progression of Kellgren-Lawrence grade are two noticeable concerns in choosing the treatment modality for meniscal root tear. Hence, root repair is a wise choice for active patients with acute root tears or those with root tears who have minimal or absent osteoarthritis [16, 19, 23, 29]. Noticeably, our results show no progression of osteoarthritis during the study time frame; nevertheless, one year is not enough time for such changes to appear.
No correlation was seen between demographic characteristics such as age or gender and functional outcomes after root repair. This finding is interesting since we expected to see variable results of self-rehabilitation between different age/sex groups, due to different levels of compliance. Frankly this study involved a limited age range, which might have masked this effect. Besides, previous studies such as Laprade et al.  reported no significant differences in clinical and radiological changes between patients older than 50 and younger than 50 years of age. The effects of age and gender on the functional outcomes of home-based rehabilitation have yet to be proven.
Time interval from the onset/ exacerbation of knee pain to surgery was significantly correlated with clinical outcomes. As a result, assigning meniscal root repair methods as soon as possible amongst eligible patients might improve the outcomes of the surgery, a notion which has been stated in the previous reports .
All patient undergoing root repair in our centers were started on a specialized rehabilitation program with a unified protocol in the non-COVID era. Outbreak of the SARS-COV-2 infection in December 2019 and isolation protocols prevented the patients from participating in such programs. Most patients were afraid to perform outdoors rehabilitation and were unable to afford home-based private physical therapy either. Therefore, we were forced to train the patients to perform simple rehabilitation tasks at home.
Our results show significant improvement in patient reported outcomes in both non-COVID and COVID era patients. Fortunately, no case of limited knee range of motion was encountered in neither group. Still and all, those who had access to specialized physical therapy (the non-COVID era group) experienced significantly better outcomes. While no study was found in the literature after the COVID-19 outbreak to take this matter into consideration, some previous reports have considered a comparison between restricted and accelerated rehabilitation [6, 27, 28]. VanderHave et al. , for instance, found a comparable successful clinical outcome regarding restricted and accelerated rehabilitation (70-94% vs. 64-96%). On the other hand, Vascellari et al.  did not report a difference in repair failure (10% vs. 13%). Noticeably, significant heterogeneity existed among previous reports.
Before jumping into any conclusions, one must consider some serious limitations of this study. The lack of MRI evaluation and a follow-up of two years are two important limitations of this study. The COVID-19 outbreak has only begun since a little more than two years ago; therefore, follow-up period could not be any longer and our sample size is relatively small. Even so, we felt compelled to share our concerns and results. Indeed, this seems to be a global on-going problem which might deeply affect not only our routine clinical practice, but also our rehabilitation protocols and postoperative care. Due to a lack of control subjects, we compared the results with historical controls who had completed their postoperative rehabilitation before the start of the pandemic. Another limitation, is the modification of the standard trans-tibial pull-out technique that we used to repair root tears . No biomechanical testing has been performed for this technique, still, its basics have been proven both biomechanically and clinically in the literature [18–20].