In this study, we found that younger age, early arthroscopic surgery (< 2 weeks), lateral meniscus tear, posterior horn tear and accompanying with ACL injury were associated with the prevalence of meniscal operation.
The clinical outcomes between partial menisectomy and meniscal repair has been hotly debated in recent years. In a study performed by Kyu et al, they observed the difference of patients-reported outcomes among patients who have underwent meniscetomy or repair for at least 10 years follow-up and claimed that meniscal repair have a superior clinical outcomes. Stein et al evaluated the rate of return to sports in athletes and found that patients underwent meniscal repair have a higher rate of return to sports (96.15%) comparing with those underwent partial menisectomy (50%) at 8.8-year follow-up. While the re-operation rates of meniscal repair is likely to be higher than that of meniscetomy at short-term follow-up. Neverthless, given the increased risk of partial meniscetomy predisposing patients to early onset degenerative changes, preversation of meniscal tissue should be attempted whenever possible[9–11]. However, to our knowledge, no study was conducted to assess the potential factors associated with the prevalence of meniscal repair. In this setting, we performed this study.
The influence of age on the clinical outcomes after arthroscopic meniscal repair have been widely reported in previous literature. Mike et al found that younger age can improve the knee function and enhance the healing rate of repaired meniscus significantly which is consistent with another study. However, substantial articles also shown an opposite conclusions. In a respective cohort study with 16-years follow-up, Steadman et al found that the failure rate of meniscus repair, knee function and patient satisfaction were not significant in patients who are 40 years or younger and older than 40 years. Their findings are supported by Sarah et al and Shane et al. In current study, surgeons tend to perform meniscus repair for younger patients (≤ 40 years). This may be explained by that most patients still worry the negative effect of age on meniscal healing as the cells, collagens, and proteoglycans in aged meniscus become disrupted and vulnerable. Additionally, the high possibilty of an early onset of OA when meiniscal tissue is resected totally or partially also makes surgeons worried.
In our study, 472/512 (84.5%) traumatic meniscus tear are accompanyed by a concurrent ACL rupture which is similar to other articles’ results. We found that ACL injury is the most important factor associated with the prevalence of meniscal repair. Many articles have reported a higher healing rate in patients undergoing a concomitant ACL reconstruction compared with those receiving isolated meniscus surgery[21–23]. They claimed that the intra-articular growth factors in bleeding from tunnels creat an ideal enviroment for meniscus healing[24, 25]. Besides, most of these meniscis tear accompanying with ACL injury are sports-related which is more common among younger patients. The above two reasons may be explained for the popularity of meniscus repair in patients having ACL injury concomitnatly.
Nonoperative treatment was commonly recommended to patients with degenerative meniscal injury. When meniscal symptoms, including pain and knee locking cannot be relieved after two weeks nonoperatively in our institution, meniscetomy and meniscus repair will be performed. Haroon et al found that the failure rate of meniscal repair is lower if meniscus are repaired within 6weeks in those patients acommpanying by ACL injury. However, we found that when arthroscopic surgery was delayed to two weeks later after injury, the ratio of undergoing meniscal repair will be reduced significantly. Meniscus is the second knee stabilizer. The meniscis tear will become more and more serious, when meniscal surgery was postponed especially when ACL deficient[26, 27]. We speculated that the severely damaged meniscus may influence surgeons’ decisions on meniscal repair as its poor healing potential.
As we all know, meniscus are classified as three zone, that is the white-white zone, white-red zone and red-red zone according to the vascularity. Theoretically, tear within the vascular zone have a higher healing rate comparing with those in avascular zone[21, 28, 29]. This is a vital factor that may affect surgeon’s treatment options. However, in our study, we did not evaluate the influence of tear zones on the prevalence of repair as they were not recorded. Some authors believed that the posterior horn root tear should be repaired whenever possible, because detachment of posterior root can disrupt continuity of the circumferential fibers and lead to loss of hoop tension[13, 30]. We also observed that surgeons tend to repair meniscal posterior horn.
No consensus being reached on whether the side of repair have differential influence on the clinical outcomes and the failure rate. Some studies found lateral meniscal repair have a higher success rate, some other articles hold an opposite opinion, while much more literature shown that the the failure rate is not associated with the side of repair. In current study, those patients with lateral meniscus tear and both sides injury are more likely to receive meniscal repair.
Despite many factors have been studied and shown to be associated with the high failure rate of maniscal repair or partial menisectomy, whether they can affect surgeons’ decision on treatment options and which will affect have not yet been evaluated. In current study, we found that aged patients especially those with concomitant ACL injury are more likely to receive maniscal repair. Additionally, in order to increase the prevalence of repair and slow down progression of OA, the surgical procedure should be performed within two weeks after meniscus tear. Lateral meniscal posterior horn injury have a higher opportunity for meniscus repair.
However, our study have some limitations. Firstly, tear zone of meniscus should be an important predictive factor for treatment options, but we failed to assess it because of data loss. More study is needed, in the future, to investigate whether meniscal tear within the red-red zone is more likely to be repaired compared with those within white-white zone. Secondly, this study were conducted based on the data in single medical center in China. We are not sure whether our findings can be generalized to general orthopaedic population in other hospital. Neverthless, we hope this study can provoke people’s attention and thinking about what are associated with the prevalence of meniscal repair and performed more related study. Finally, all arthroscopic meniscal surgery were performed by three different high experienced surgeons, thus option bias may exists, however, we believed this can reflect the realistic clinical issue.