Many articles have demonstrated that the loss of meniscal tissue can lead to early onset of degenerative knee joint changes in the long term. Verdonk et al[21] and Hall et al[18] claimed that the removal of 30% of meniscal tissue may increase joint surface contact forces by approximately 300%. Thus, a consensus has been reached that meniscal tissue should be preserved as much as possible[4, 8, 24]. The already popularized method to preserve meniscal tissue is the arthroscopic meniscus repair procedure.
With the development of meniscal repair surgery, many suture devices, such as the RapidLoc, T-Fix and FasT-Fix, and three different techniques (inside-out, outside-in and all-inside) have been used[2, 16]. Several studies have been performed to investigate the clinical outcomes with different suture materials and repair techniques and have shown that the results are comparable with regard to the patient-reported outcomes and meniscal healing rate[5, 10, 15]. In our study, we used the FasT-Fix suture device for all patients with all-inside meniscal repair, which is the most widely used procedure. However, the FasT-Fix device is expensive. One of the most common questions that patients ask before surgery is how much they need to pay for the operation. However, that cannot be answered accurately, as the surgical cost is associated with the number of sutures. Given that the severity of meniscus tears can be indirectly reflected by the number of sutures used during the repair process, we implemented this study[3, 23]. First, the predictive factors for a large number of sutures can help surgeons identify patients with a high risk of serious meniscus tears and advise them to undergo meniscus repair early. In addition, it is also helpful for surgeons to give patients an expectation of costs preoperatively, and the cost may be reduced for other patients if risk factors can be avoided.
In the current study, we found that patients who underwent meniscal repair within one month after meniscus tear were more likely to use few sutures. The meniscus is an important second stabilizer of the knee joint. When it tears, especially in those patients with ACL deficiency, the knee is unstable[6, 17]. The meniscus becomes susceptible to additional force, particularly when surgery is delayed, and the incidence of subsequent meniscal and chondral lesions is significantly increased, which has been reported in a large number of studies[7, 17, 20]. Thus, a severely teared menisci can only be repaired with a larger number of sutures. Additionally, our findings provide further evidence for the opinion that meniscal repair should be performed early.
Theoretically, medial menisci are more vulnerable to shear forces than lateral menisci. Because the medial meniscus is attached to the medial collateral ligament, its mobility is much larger than that of the lateral meniscus, which may subsequently increase the severity of meniscal tears[1, 13]. Additionally, for most patients, arthroscopic surgery was delayed, which has been confirmed to be a potential risk factor for increased meniscal injury, especially in those patients with concomitant ACL rupture. Lateral meniscus tears are not associated with the injury-to-surgery interval[7]. The above two reasons may explain why the medial meniscus is more likely to need more sutures to be repaired.
To identify factors that are associated with the number of sutures used during meniscal repair and thus reduce surgical cost and avoid meniscus tears becoming increasingly serious, we performed this study. Our results demonstrated that lateral meniscus injury and performing operations within one month after injury tend to require fewer suture devices. To our knowledge, this is the first study to investigate the risk factors that can increase the use of suture devices. Our findings can not only give patients an evidence-based opinion about the surgical cost preoperatively but also provide further evidence that arthroscopic surgery should be performed early (< 1 month).
However, our study has some limitations. First, this study was conducted based on data from a single medical center in China. We are not sure whether our findings can be generalized to the general orthopedic population in other hospitals. Nevertheless, we hope this study can provoke attention and thinking about what factors are associated with the use of a large number of sutures and how to reduce surgical cost for patients. Finally, all arthroscopic meniscal repairs were performed by three different highly experienced surgeons; thus, option bias may exist. However, we believe this study reflects realistic clinical issues.