Abstract
PurposeNon-surgical treatment of primary patellar dislocation has a high risk of recurrent dislocation; thus, we tried to identify injuries in which sites of the medial patellofemoral ligament (MPFL) were most associated with recurrent dislocation by analyzing relevant original literature in order to provide improved suggestions on early surgical treatment.MethodsAccording to the preset retrieval strategy, the original studies were retrieved until January 2020 using MEDLINE, Embase and Cochrane Library. Review Manager 5.3 software was used to summarize and compare the differences of recurrent dislocation of MPFL injuries at different attachments.ResultsAlthough the incidence of recurrent patellar dislocation at the femoral attachment of MPFL was higher overall (femoral only vs. patellar only vs. combined: 37.6% vs. 32.3% vs. 35.8%), no statistical difference was found among the three groups (femoral only vs. patellar only, RR = 1.32 [95% CI 0.89–1.95]; P = 0.17) (femoral only vs. combined, RR = 1.15 [95% CI 0.59–2.22]; P = 0.68) (patellar only vs. combined, RR = 0.94 [95% CI 0.69–1.29]; P = 0.72). In addition, the sulcus angle of recurrent dislocation group is significantly greater than that in the non-recurrent dislocation group (MD = 3.06 [95% CI 0.42–5.70]; P = 0.02).ConclusionsBased on the pooled data collected from the original studies available, the risk of recurrent patellar dislocation due to damage to the MPFL at different sites did not differ. Additionally, the sulcus angle in the group with recurrent dislocation was considerably higher when comparing with the group without recurrent dislocation, that is, the shallower and flatter of the trochlear groove, the higher the risk of recurrent patellar dislocation.
Highlights
Patellar dislocation is a common traumatic disease, with the incidence of primary patellar dislocation in the population being 23–42 per 100,000 per year
After conducting summary analysis on the differences in femoral articular sulcus angle, we found that the recurrent dislocation of sulcus angle was significantly greater than non-recurrent dislocation (MD, 3.06, P = 0.02) (Fig. 6)
We have found that the femoral articular sulcus angle in the group with recurrent dislocation was significantly higher than that in the group without recurrent dislocation, indicating that sulcus angle increased, that is, the superficial trochlear groove would increase the risk of recurrent dislocation of the patella
Summary
Patellar dislocation is a common traumatic disease, with the incidence of primary patellar dislocation in the population being 23–42 per 100,000 per year. Numerous studies have compared the clinical effects of primary patellar dislocation surgery and nonsurgical treatment, suggesting that the redislocation rate of surgical treatment is relatively low, but no difference lies in the long-term functional results [8–12]. A Cochrane systematic review concluded that the short-term effect of primary patellar dislocation surgery was better than that of non-surgical treatment, the level of evidence in these studies was low, having a high risk of bias [13]. For this reason, there are still many studies supporting nonsurgical treatment of primary patellar dislocation [14, 15]. Considering the high risk of recurrent dislocation in non-surgical treatment, it is necessary to identify which factors are most associated with recurrent dislocation and in order to put forward more optimized surgical treatment
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