gms | German Medical Science

Objectives: In chronic injuries with high grade posterolateral rotational instabilities (PLRI) of the knee (Fanelli Type B), anatomic reconstruction has shown excellent results. Particularly procedures described by Arciero and LaPrade are well-established as open surgeries and have shown equal restoration of joint stability. Recently, these open techniques have been described as arthroscopic procedures and as treatment of choice in high-grade posterolateral corner injuries.

In this study, we present and compare clinical results of the first patient cohort to undergo these novel arthroscopic techniques.

Methods: 19 Patients with a high-grade injury (Fanelli Type B) of the posterolateral corner were included in this study. Inclusion criteria were chronic injuries (> 3 weeks) with a combined varus and PLRI and ruptured PCL.

Surgeries were all performed by the same surgeon according to techniques described by Frings et al. (Arciero's technique - group 1) and Kolb et al. (LaPrade's technique - group 2) with additional PCL reconstruction.

Follow-up was conducted at 6 months after surgery. Clinical examination evaluated ROM, external rotational (ER) and varus instability and posterior drawer (PD) of both knees (measured as side-to-side-difference). Subjective scores included the IKDC subjective score, Lysholm Score, Tegner Activity Scale (TAS) and Numeric Rating Scale (NRS).

Results and Conclusion: All patients in both groups presented with Fanelli Type B injuries with varus opening up to 10mm, an increased external rotational instability in dial test and subjective instability. 16 patients have been available for 6 months follow-up (8 Arciero, 8 LaPrade).

Preoperative PD was 14.75±2.05mm in group 1 and 14.8±1.58mm in group 2 (side-to-side difference).

At 6 months follow-up, patients of group 1 showed a flexion deficit of 10.71±14.56° vs. 10.83±10.21° in group 2, compared to preoperative examination. ER was -4.71±3.95° compared to the contralateral knee in 30° flexion and -3.71±5.99° in 90° flexion in group 1. Group 2 showed a side-to-side difference in ER of -3.33±3.44° in 30° flexion and -4.83±3.25° in 90° flexion. All patients presented stable under varus stress. PD was 2.61±0.93mm as side-to-side difference in group 1 and 3.33±1.01mm in group 2.

Subjective scores in group 1 vs. group 2 showed 69.6 vs. 62.38 points in the IKDC Subjective Score, 80.2 vs. 74.6 in Lysholm Score with a TAS of 4.2 vs. 3.8 and a NRS of current pain of 1.2 vs. 2.8. One patient in each group reported intermittent subjective instability.

Our preliminary results at 6 months postoperative, despite representing only a small sample size of a running study, indicate a sufficient restoration of PLRI, varus instability and PD. Both groups present with a similar flexion deficit, which might be due to the short follow-up period after operation.

These findings must be re-evaluated in further long-term follow-ups and with a larger group size in order to detect statistically significant differences.