Purpose Clinical outcomes between reattachment of the superior peroneal retinaculum (SPR) and the bone block procedure were compared in this study to elucidate which procedure was safer and more effective. Methods From 2012 to 2016, 25 patients with recurrent peroneal tendon dislocation underwent the bone block procedure (group A), and another 22 patients underwent reattachment of the SPR (group B). American Orthopaedic Foot and Ankle Society (AOFAS) ankle‐hindfoot score, Ankle Activity Score (AAS), time to return to sports activity, rate of return to sports level, range of motion (ROM) of the ankle, rate of recurrence, and overall patient satisfaction were collected to evaluate outcomes between the two groups. Results In group A, 24 patients followed up at a mean period of 42.5 ± 16.7 months. The mean postoperative AOFAS score was 92.9 ± 3.9. The median time to return to sports activity was 6.0 months (IQR 4.3–6.0 months) with 19 patients (79.2%) returning to their previous sports level. Two patients experienced recurrent dislocation, and 22 patients (91.7%) were satisfied with the procedure. In group B, 20 patients followed up at a mean period of 35.8 ± 15.3 months. The mean postoperative AOFAS score was 95.0 ± 4.2. The median time to return to sports activity was 5.0 months (IQR 4.0–5.0 months) with 18 patients (90.0%) returning to their previous sports level. No recurrence was reported, and 18 patients (90.0%) were satisfied with the procedure. The time to return to sports activity in group B was significantly shorter than that in group A. There was no significant difference in complications or clinical outcomes between the two procedures. Conclusion Both procedures offered satisfactory results for recurrent peroneal tendon dislocation with low rates of recurrence and complications. However, the time to return to sports activity after the reattachment of the SPR was shorter than that after the bone block procedure. Level of evidence Retrospective Comparative Study, Level III.

Background: Compared with computed tomography (CT), magnetic resonance imaging (MRI) might overestimate the condition of osteochondral lesions of the talus (OLTs) owing to subchondral bone marrow edema and the overlying cartilage defect. However, no study has compared MRI and CT directly in evaluating OLTs with subchondral cysts. Purpose: To compare the reliability and validity of MRI and CT in evaluating OLTs with subchondral cysts. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: An institutional radiology database was queried for inpatients diagnosed with OLTs with subchondral cysts who had undergone surgical treatment between May 2015 and October 2019. A total of 48 patients met the inclusion criteria. Based on our measurement method, 2 experienced observers who were blinded to the study independently measured the length, width, and depth of the cysts using MRI and CT. The classification of cystic lesions was also performed based on MRI and CT findings. Results: Interobserver reliability was almost perfect, with intraclass correlation coefficients (ICCs) ranging from 0.935 to 0.999. ICCs for intraobserver reliability ranged from 0.944 to 0.976. The mean size of cysts measured on MRI (length, 13.38 ± 4.23 mm; width, 9.28 ± 2.28 mm; depth, 11.54 ± 3.69 mm) was not significantly different to that evaluated on CT (length, 13.40 ± 4.08 mm; width, 9.25 ± 2.34 mm; depth, 11.32 ± 3.54 mm). The size of subchondral cysts was precisely estimated on both MRI and CT. The MRI classification and CT classification revealed almost perfect agreement (kappa = 0.831). Conclusion: With our measurement method, both MRI and CT were deemed to be reliable and valid in evaluating the size of subchondral cysts of OLTs, and the MRI classification was well-correlated with the CT classification. The presented measurement method and classification systems could provide more accurate information before surgery.

IntroductionLarge cystic osteochondral lesions of the talus (OLTs) have been shown to have inferior clinical outcomes after reparative techniques such as bone marrow stimulation. Autologous osteochondral transplantation has been viewed as an alternative choice for treating these lesions, but donor-site morbidity has limited its application. Excellent clinical outcomes have been shown in repairing these types of lesions with autologous osteoperiosteal grafts, and these outcomes are achieved at a low cost and without donor-site morbidity in the normal knee joint. This will be the first randomised controlled trial to compare the two surgical techniques, and recommendations for the treatment of patients with large cystic OLTs will be provided.Methods and analysisA non-inferiority randomised controlled trial will be conducted. A total of 70 participants with clinically diagnosed large cystic OLTs will be randomly allocated to either the experimental group or the control group at a ratio of 1:1. The experimental group will be treated with autologous osteoperiosteal cylinder graft transplantation, while the control group will be treated with autologous osteochondral transplantation. The primary outcome measure will be the American Orthopaedic Foot & Ankle Society Ankle-Hindfoot Score and the Short Form 12 (SF-12) questionnaire. Secondary outcome measures will include the secondary arthroscopy International Cartilage Repair Society score, the Magnetic Resonance Observation of Cartilage Repair Tissue score, the Tegner activity level score, the visual analogue scale, routine X-rays, CT and complications. These parameters will be evaluated preoperatively, as well as at 3, 6, 12, 24, 36 and 60 months postoperatively. In this trial, we hypothesised that both procedures offer good results for the treatment of patients with large cystic OLTs, and occurrence of donor-site morbidity in autologous osteoperiosteal cylinder graft transplantation group is less than that in autologous osteochondral transplantation group.Ethics and disseminationThe current study was approved by the board of research ethics of Peking University Third Hospital Medical Science Research Ethics Committee. The results of this study will be presented at national and international conferences and published in peer-reviewed journals.Trial registration numberNCT03347877.