Successful ACL repair by dynamic intraligamentary stabilisation is non-inferior in functional performance and worse in proprioception compared to healthy controls in a case-matched study.

Purpose: The primary aim of this study was to assess non-inferiority in functional performance of the knee after dynamic intraligamentary stabilisation (DIS) surgery at a minimal follow-up of 1 year compared to healthy controls, based on limb symmetry index (LSI) of the single leg hop test (SLH). Additionally, functional performance based on the single leg triple hop test (SLTH) and side hop test (SH), proprioception and subjective outcome were evaluated.

Methods: A total of 45 DIS patients were 1-to-1 matched to a healthy control. Functional performance was evaluated by LSI and absolute values on the SLH, SLTH and SH. Proprioception was assessed by joint position sense (JPS) test and International Knee Documentation Committee (IKDC) scores were obtained.

Results: Non-inferiority in functional performance after DIS compared to healthy controls was confirmed based on the mean LSI of the SLH and SLTH (97.6% vs. 99.6% and 97.5% vs. 100.6%, respectively) and non-confirmed on the SH (98.8% vs. 100.0%, respectively). No significant differences were found in absolute value of the SLH and SLTH and a significantly higher absolute value of the SH was found in the DIS group ( = 0.01). JPS absolute angular error was significantly higher in the DIS group compared to the control group ( = 0.01). The median IKDC score of the DIS group was significantly lower (92, IQR 85-95) than the control group (100, IQR 99-100),  < 0.001.

Conclusions: In conclusion, functional performance after DIS was confirmed non-inferior compared to healthy controls based on the SLH and SLTH, although non-confirmed on the SH.

Level Of Evidence: Level III.