PurposeTo evaluate clinical outcomes as well as return to sports (RTS) and return to work (RTW) rates following anatomic lateral ankle ligament reconstruction with a tendon autograft for chronic lateral ankle instability (CLAI) in a high-risk population, and to compare these outcome parameters between patients having received a gracilis tendon autograft (GT) and free split peroneus brevis tendon (PBT) autograft.MethodsTwenty-eight consecutive patients, who were diagnosed with CLAI, presenting with ≥ 1 risk factor (ligamentous hyperlaxity, insufficient substance of native ligament and/or high-demand athlete), who underwent ankle ligament reconstruction with a tendon autograft between January 2011 and December 2018, were included in this retrospective study. At 63.7 ± 28.0 months (24–112), 23 patients with a mean age of 29.7 ± 10.9 years were available for follow-up. The Karlsson Score, the Foot and Ankle Outcome Score (FAOS), the Tegner Activity Scale and the visual analog scale (VAS) for pain were collected at a minimum follow-up of 24 months. RTS and RTW were evaluated by questionnaire. A subgroup analysis with regard to the graft used for ankle ligament reconstruction (GT versus PBT) was performed.ResultsPatients reported a Karlsson score of 82.1 ± 17.5 (37–100), a FAOS score of 87.8 ± 8.4 (73–99), a median Tegner activity scale of 5.0 (IQR 4–6) and a VAS for pain of 0.5 ± 0.9 (0–4) at rest and of 2.0 ± 2.1 (0–7) during activities at final follow-up. Postoperatively, 96% of patients had returned to sports after 8.3 ± 6.2 months. All patients (100%) had returned to work at 3.5 ± 5.7 (0–24) months, with 87% reporting an equal or improved working ability compared to that preoperatively. Postoperatively, exercise hours per week were significantly reduced compared to preoperatively in patients with a split PBT (n = 12; 13.0 ± 12.9 to 5.6 ± 6.4 h, p = 0.038) autograft as opposed to patients with a GT autograft (n = 11; 13.1 ± 8.7 to 12.4 ± 7.1 h, n.s.). No other group differences were observed.ConclusionGood patient-reported outcomes as well as excellent RTS and RTW rates can be achieved in high-risk patients undergoing ankle ligament reconstruction with a tendon autograft for CLAI. These results may be helpful in preoperatively managing patients’ expectations regarding sports- and work-related outcomes and provide tangible data on the expectable time frame of the individual return to sports and work trajectory.Level of evidenceIV.