Abstract
Objectives:
The aims of this study were to investigate (1) the association between medial and lateral PTS and clinical failure following meniscus repair using both plain film radiographs and MRI modalities, (2) to identify a potential PTS threshold for reliable prediction of clinical failure or suboptimal PRO metrics, and (3) to quantify the level of the agreement between radiographic and MRI modalities in calculating PTS. The hypothesis was that there would be a negative correlation between medial and lateral PTS and clinical outcomes.
Methods:
Patients who underwent meniscus repair at a tertiary referral institution between February 2020 and October 2022 were reviewed and included if they had a documented meniscus tear confirmed on magnetic resonance imaging (MRI) and received surgical repair. Clinical failure was defined as meeting any of the following criteria: (a) explicit re-tear/reinjury, (b) any reoperation for meniscus-related complications which includes procedure-related readmissions, (c) return to the emergency department (ED), (d) infection, or (e) poor short to medium-term (6- and 12-month) patient-reported outcome scores assessed using the validated International Knee Documentation Committee (IKDC) score. A Cox proportional hazards model was used to assess the association of medial and lateral PTS with time to clinical failure. Medial and lateral PTS were measured preoperatively using both MRI and plain film radiographs according to established methods from the literature.
Results:
A total of 132 patients met inclusion criteria and were included in the analysis. For lateral PTS, the mean ±S D values were 6.6 ± 3.3 and 5.8 ± 3.1 degrees using radiograph and MRI, respectively. For medial PTS, the values were 6.9 ± 3.1 and 3.6 ± 2.3 degrees for radiograph and MRI, respectively. Clinical failure was observed in 47 (35.6%) patients overall (5 reinjuries, 3 return to ED, 14 reoperations, 28 failing to meet optimal IKDC >60 at 6 months, and 6 failing to meet optimal IKDC >60 at 1 year, with >1 reason for clinical failure possible). No association was found between PTS (lateral or medial) and clinical failure before or after adjusting for age, sex, and presence of osteoarthritis. The area under the receiver operating characteristic (ROC) from each Cox model was <0.60, indicating poor discrimination of failure by PTS at 6- and 12-months. Thus, PTS threshold analysis did not identify clinically relevant predictive thresholds for failure at either time point postoperatively. Bland-Altman plots comparing MRI versus radiograph PTS measurements revealed a mean difference in lateral PTS of -0.80 (95% limits of agreement [LOA]: -8.3 to 6.8) and -3.3 (95% LOA: -9.8 to 3.2) for medial PTS.
Conclusions:
This study did not find a statistically significant association between medial or lateral PTS and time to clinical failure following meniscus repair, irrespective of the imaging modality used. Further, the analysis did not identify clinically relevant PTS thresholds for predicting failure or suboptimal patient-reported outcomes at either 6 or 12 months postoperatively. This study also reports significant heterogeneity between radiographic and MRI modalities for quantification of PTS.
