Incidence of concomitant chondral/osteochondral lesions in acute ankle fractures and their effect on clinical outcome: a systematic review and meta-analysis

Introduction Despite successful osteosynthesis, some patients report residual symptoms after ankle fractures. One of the reasons behind the postoperative complaints might be traumatic concomitant chondral lesions (CL) and/or osteochondral lesions (OCL) within the ankle joint. The study aims to systematically review the incidence of CL and/or OCL in ankle fractures and to assess their effect on the clinical outcome. Materials and methods This work was conducted according to PRISMA checklists. A systematic literature search was performed using following keywords: "Ankle Fractures" OR "Trimalleolar Fracture" OR "Bimalleolar Fracture" OR "Maisonneuve fracture" OR "Malleolus Fracture" AND "Cartilage" OR "Cartilage Diseases" OR "Cartilage, Articular" OR "chondral" up to March 2020. The identified articles were analysed to determine the incidence of CL and/or OCL. Included studies in the meta-analysis assessed possible cartilage damage through arthroscopy or MRI immediately after traumatic ankle fractures and described the postoperative clinical outcome. Results The search identified a total of 111 publications; 19 described the incidence of CL and/or OCL after ankle fractures; six met the criteria to be included in the meta-analysis: five (n = 293) diagnosed CL and/or OCL through arthroscopy during ORIF and one study (n = 153) used preoperative MRI. The clinical outcome was evaluated in four studies (n = 177) using AOFAS score and in two (n = 269) using FAOS score. The mean incidence of arthroscopically detected CL and/or OCL was 65 +/- 21% [95% CI 53.9 to 76.72]. The cumulative meta-analysis sample size comprised a total of 400 Patients (170 with and 230 without CL and/or OCL) available for a mean follow-up of 23.9 +/- 11.5 months [95% CI 11.79 to 36.07]. The average age was 44.3 +/- 5.5 years [95% CI 38.57 to 50.13]. The meta-analysis revealed a mean AOFAS score of 91.2 +/- 4.8 [95% CI 83.53 to 98.93] with versus 94.4 +/- 4.7 [95% CI 86.81 to 102.07] without CL and/or OCL (p = 0.15) and a mean FAOS score of 73.2 +/- 11.31 [95% CI - 28.44 to 174.85] with versus 79.0 +/- 18.4 [95% CI - 86.77 to 244.87] without CL and/or OCL (p = 0.18). Conclusions CL and/or OCL appear very frequently after ankle fractures. A tendency towards a favourable short- to mid-term clinical outcome was noticed in ankle fractures without CL and/or OCL, however without reaching statistical significance.