## 4 Discussion  
This study showed the effectiveness and validity of the retromalleolar groove deepening in recurrent peroneal tendon dislocation in patients with a flat distal fibula. All patients achieved excellent clinical outcomes, and no recurrence occurred. The mean time to return to sports is quite short, and in 7 months, all patients could perform physical activities again. Only one patient affected by collagen disease incurred several difficulties during rehabilitation, with instability and chronic pain. The groove deepening combined with the repair of SPR is a valuable technique in the treatment of recurrent peroneal tendon dislocation. Undiagnosed peroneal tendon disorders can potentially lead to long-lasting complications, such as recurrent dislocations, peroneal tendon damage or degeneration, chronic lateral ankle discomfort, and tendon inflammation. Therefore, it is crucial to identify the pathology and assess the necessity for appropriate treatment. Surgical intervention is necessary for chronic peroneal tendon dislocation, whether in athletes or non-athletes. According to the ESSKA-AFAS international consensus statement on peroneal tendon pathologies, surgical stabilization is recommended as the primary treatment, with a particular focus on deepening the retromalleolar groove in athletes [28]. Numerous operative techniques have been described. Currently, there have been no prospective randomized studies conducted to determine the superiority of one approach over another [19; 29]. All these procedures focus on stabilizing the peroneal tendons within the retrofibrular groove, whether achieved through the correction of anatomical malformations or the reinforcement of the SPR. A systematic review from 2016 indicated that patients who underwent both superior peroneal retinaculum (SPR) repair and deepening of the retromalleolar groove had a higher likelihood of returning to sports compared to those who only underwent SPR repair [30]. But, only a few years later, in 2020, [PERSON] et al. proposed that in cases of traumatic peroneal tendon dislocation, reattaching the peroneal retinaculum without deepening the groove may be adequate. This is because the primary concern in traumatic cases is the detachment of the superior retinaculum, which serves as the primary restraint for the peroneal tendon [31]. Surely, this technique is less invasive in comparison with others [32]; however, in cases of patients with a congenital convex fibular groove, this straightforward repair is unlikely to provide stability to the subluxated tendon. [PERSON] et al. indicated the effectiveness of this technique in their series of 14 surgically treated patients with peroneal dislocation. During the surgical procedure, thirteen patients were found to have a convex peroneal groove, and all fourteen had an intact peroneal retinaculum [33]. Research has demonstrated that the morphology of the retromalleolar groove is a contributing factor in peroneal tendon pathology, with flat and convex grooves showing the strongest association [34]. The surgical technique used in this study preserves the natural fibrocartilage within the malleolar groove, facilitating smoother peroneal tendon gliding and lowering the risk of tendon shearing [35]. However, some authors have expressed concerns about this technique, citing worries about the increased force needed to compress the posterior cortex of the fibula, which could potentially harm the fibrocartilage or even result in a fibula fracture [36]. This complication was not observed in our study. According to the authors, the deepening groove technique should be considered when intraoperative confirmation reveals groove dysplasia. A recent meta-analysis [37] compared four surgical techniques in patients with chronic peroneal instability: SPR repair or replacement, groove-deepening procedures (often combined with additional SPR operations), rerouting procedures, and bony procedures.