MRI analysis of peripheral soft tissue composition, not body mass index, correlates with outcomes following anterior cruciate ligament reconstruction
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To utilize MRI to assess the relationship between BMI, peripheral soft tissue composition about the knee, and surgical outcomes in patients undergoing primary ACL reconstruction. It was hypothesized that a fatty periarticular soft tissue composition may be better than BMI at predicting poor outcomes after ACL reconstruction.
Fifty-eight patients who underwent primary acute ACL reconstruction were identified from the surgical database and their data were retrospectively reviewed. Patients were selected based on availability of 2-year IKDC outcome scores, BMI data, and preoperative MRI studies. To approximate peripheral soft tissue composition, novel measurements of axial MRI images were employed using PACS ROI measurement tool. Relationships were assessed between IKDC outcome scores and measures of body habitus including BMI, total knee area, knee fatty-connective tissue area, and fatty-connective tissue to bone size ratio.
The median BMI was 24.3 kg/m2 (range 18.5–36.9). Median IKDC score was 81.0 (range 46–100). BMI was correlated with total knee area (R = 0.72) and periarticular fat (R = 0.53). Neither continuous BMI (n.s.) nor total knee area (n.s.) was predictor of IKDC outcomes scores. Periarticular fatty-connective tissue trended towards predicting negative outcomes (n.s.). Periarticular fatty-connective tissue to bone size ratio was a significant negative predictor of IKDC scores (p = 0.03). Patients with more fat than bone on axial MRI (ratio > 1, N = 34) reported a lower mean IKDC score compared to patients with a ratio < 1 (N = 24) (77.2 vs. 87.7, p = 0.0028). The top quartile (N = 14) of these ratios reported a mean IKDC score of 68.9, compared to 87.3 of the bottom quartile (p = 0.0001).
Periarticular soft tissue composition, as approximated by the novel MRI analysis of this study, is a better predictor of outcomes following ACL reconstruction than is BMI. This information can be utilized in guiding surgeon and patient expectations following surgery, either via a direct application of these measurements or heightened awareness of the importance of peripheral body habitus.
Level of evidence
KeywordsACL BMI Adipose tissue MRI ACL reconstruction Outcomes
Compliance with ethical standards
Conflict of interest
The authors declared that they have no conflict of interest.
IRB approved by Helen Panageas, Director of NYU School of Medicine IRB. IRB#: i15-00863.
- 4.Cox CL, Huston LJ, Dunn WR, Reinke EK, Nwosu SK, Parker RD et al (2014) Are articular cartilage lesions and meniscus tears predictive of IKDC, KOOS, and Marx activity level outcomes after anterior cruciate ligament reconstruction? A 6-year multicenter cohort study. Am J Sports Med 42:1058–1067CrossRefGoogle Scholar
- 19.Pietrosimone B, Kuenze C, Hart JM, Thigpen C, Lepley AS, Blackburn JT et al. (2017) Weak associations between body mass index and self-reported disability in people with unilateral anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc. https://doi.org/10.1007/s00167-017-4663-y CrossRefPubMedGoogle Scholar