Increased Posterior Tibial Slope as a Risk Factor for Failure of Healing of Medial Meniscal Root Tears After All-Inside Suture Anchor Repair

Background: Investigating the possible association between medial posterior tibial slope (PTS) and healing of repaired medial meniscal posterior root tear (MMPRT) is very limited in the relevant literature. Purpose/Hypothesis: The purpose of this study was to investigate the association between medial PTS and healing of MMPRTs after all-inside suture anchor repair. We hypothesized that there would be a significant difference in the medial PTS between the healing and nonhealing groups. Study Design: Case-control study; Level of evidence, 3. Methods: From March 2008 to December 2023, consecutive patients who underwent MMPRT repair using the all-inside repair technique with suture anchors were selected. MMPRTs were repaired in patients with grade 1 or 2 chondromalacia according to the Outerbridge classification of the medial compartment, minimal extrusion (<3 mm), normal limb alignment (hip-knee-ankle angle <3°), and minimally displaced root tears. The patients were divided into 2 (healed and nonhealed) groups according to the magnetic resonance imaging (MRI) appearance of the repaired MMPRT at 6 months after surgery. The medial PTS was measured on the mid-central slice of the sagittal MRI. The 2 groups were compared according to age, body mass index (BMI), and PTS. Results: There were 47 patients in the healed group and 25 patients in the nonhealed group. Age and BMI did not differ significantly between the 2 groups ( P = .763 and P = .073). PTS of the nonhealed group was significantly higher than that of the healed group (5.9 ± 2.2 vs 4.4 ± 2.5; P = .017). Logistic regression analysis demonstrated that the PTS was associated with failure to heal after the MMPRT repair (odds ratio [OR], 1.31; 95% CI, 1.04–1.73; P = .022). However, age and BMI were not associated with nonhealing after the MMPRT repair (OR = 0.99; 95% CI, 0.93–1.08; P = .759; OR = 0.85; 95% CI, 0.70–1.02; P = .079). Conclusion: Increased PTS was associated with failure to heal MMPRT after all-inside suture anchor repair. This factor should be considered when counseling patients undergoing MMPRT repair.