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Objectives and questions: Posterolateral tibial impression (‘apple bite’) fractures (PTIFs) can lead to an increased pivot shift in biomechanical studies after anterior cruciate ligament reconstruction (ACLR) due to reduced lateral meniscus (LM) support. However, given the limited number of available studies, it remains unclear whether reduction of the PTIF is necessary. This study aimed to compare clinical outcomes of nonsurgical versus surgical treatment of PTIFs in patients with concomitant ACL injury at two university hospitals (UH).

Material and methods: A retrospective review of patient records and magnetic resonance imaging (MRI) scans was performed to identify patients with an ACL injury and a PTIF with ≥2 mm impression and ≥50% loss of LM bony support between January 2018 and September 2023. At UH1, PTIFs were surgically addressed according to Menzdorf et al., whereas at UH2 only ACLR was performed.Thirty-two patients (mean age: 35.9 ± 11.2 years) were included. Nineteen patients underwent arthroscopically assisted transtibial reduction (FR group) with simultaneous ACLR or refixation [6× refixation of bony ACL tear, 7× Semitendinosus (S) graft, 6× Semitendinosus + Gracilis (S+G) graft; no anterolateral tenodesis (LET)]. Thirteen patients were treated without fracture reduction (NFR group), receiving ACL reconstruction alone [6× Quadriceps tendon (Q), 7× S graft, 2× with LET]. Patient-reported outcome measures (PROMs) were assessed using the visual analog scale (VAS), International Knee Documentation Committee (IKDC) score, Knee injury and Osteoarthritis Outcome Score (KOOS), Lysholm score, Tegner activity score and Anterior Cruciate Ligament-Return to Sports after Injury (ACL-RSI) scale with a minimum follow-up (FU) of 24 months after surgery. Clinical examination included side-to-side differences in the Lachman test. The Mann-Whitney U test was used to compare the groups.

Results: Mean FU was 49.3 months. No significant differences in demographic characteristics were observed except for sex distribution [FR: 7 male, 12 female vs. NFR: 13 male; age: 39.3 ± 12.5 vs. 30.9 ± 6.5 years; FU: 49.9 ± 17.9 vs. 45.8 ± 21.3 months; BMI: 26.1 ± 4.3 vs. 25.2 ± 3.7 kg/m²]. Most PTIFs were classified as Menzdorf type 2b (22/32). Both groups demonstrated good to excellent clinical outcomes, with no statistically significant differences in PROMs (FR vs. NFR; ΔVAS: -5.7 ± 3.9 vs. –5.2 ± 3.2; IKDC: 77.4 ± 14.3 vs. 82.1 ± 19.7; KOOS: 82.4 ± 11.9 vs. 83.6 ± 17.7; Lysholm: 83,3 ± 13,3 vs. 85.5 ± 17.4; ΔTegner: -1.1 ± 0.9 vs. -1.6 ± 1.9; ACL-RSI: 74.7 ± 21.6 vs. 59.5 ± 32.7) or Lachman test results (side-to-side difference 2.2 ± 1.6 mm vs. 1.7 ± 0.8 mm). Two patients in each group required arthrolysis. Three FR patients underwent screw removal due to implant-related discomfort. No ACL graft ruptures occurred.

Discussion and conclusions: Regardless of PTIF management involving ≥2 mm of impression and ≥50% loss of bony support, both groups showed good to excellent outcomes after ACL reconstruction.