Quantitative US Elastography Can Be Used to Quantify Mechanical and Histologic Tendon Healing in a Rabbit Model of Achilles Tendon Transection.
Purpose To determine the time-dependent change in strain ratios (SRs) at the healing site of an Achilles tendon rupture in a rabbit model of tendon transection and to assess the correlation between SRs and the mechanical and histologic properties of the healing tissue. Materials and Methods Experimental methods were approved by the institutional animal care and use committee. The Achilles tendons of 24 New Zealand white rabbits (48 limbs) were surgically transected. The SRs of Achilles tendons were calculated by using compression-based quantitative ultrasonographic elastography measurements obtained 2, 4, 8, and 12 weeks after transection. After in vivo elastography, the left Achilles tendon was harvested for mechanical testing of ultimate load, ultimate stress, elastic modulus, and linear stiffness, and the right tendons were harvested for tissue histologic analysis with the Bonar scale. Time-dependent changes in SRs, mechanical parameters, and Bonar scale scores were evaluated by using repeated-measures analysis of variance. The correlation between SRs and each measured variable was evaluated by using the Spearman rank correlation coefficient. Results Mean SRs and Bonar scale values decreased as a function of time after transection, whereas mechanical parameters increased (P < .001). SR correlated with ultimate stress (ρ = 0.68, P <.001,) elastic modulus (ρ = 0.74, P <.001), and the Bonar scale (ρ = 0.87, P <.001). Conclusion Quantitative elastography could be a useful method with which to evaluate mechanical and histologic properties of the healing tendon.©RSNA, 2017 Online supplemental material is available for this article.
From the Department of Orthopaedic Surgery, Graduate School of Medical and Pharmaceutical Sciences (Y.Y., S.Y., T.S., T.F., Y.A., R.A., Kazuhisa Takahashi), Clinical Research Center (K.N.), and Center for Frontier Medical Engineering (T.Y.), Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, Japan; and Funabashi Orthopaedic Hospital, Funabashi, Japan (Kenji Takahashi).
Yohei
Y
Yamamoto
From the Department of Orthopaedic Surgery, Graduate School of Medical and Pharmaceutical Sciences (Y.Y., S.Y., T.S., T.F., Y.A., R.A., Kazuhisa Takahashi), Clinical Research Center (K.N.), and Center for Frontier Medical Engineering (T.Y.), Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, Japan; and Funabashi Orthopaedic Hospital, Funabashi, Japan (Kenji Takahashi).
Satoshi
S
Yamaguchi
From the Department of Orthopaedic Surgery, Graduate School of Medical and Pharmaceutical Sciences (Y.Y., S.Y., T.S., T.F., Y.A., R.A., Kazuhisa Takahashi), Clinical Research Center (K.N.), and Center for Frontier Medical Engineering (T.Y.), Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, Japan; and Funabashi Orthopaedic Hospital, Funabashi, Japan (Kenji Takahashi).
Takahisa
T
Sasho
From the Department of Orthopaedic Surgery, Graduate School of Medical and Pharmaceutical Sciences (Y.Y., S.Y., T.S., T.F., Y.A., R.A., Kazuhisa Takahashi), Clinical Research Center (K.N.), and Center for Frontier Medical Engineering (T.Y.), Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, Japan; and Funabashi Orthopaedic Hospital, Funabashi, Japan (Kenji Takahashi).
Taisuke
T
Fukawa
From the Department of Orthopaedic Surgery, Graduate School of Medical and Pharmaceutical Sciences (Y.Y., S.Y., T.S., T.F., Y.A., R.A., Kazuhisa Takahashi), Clinical Research Center (K.N.), and Center for Frontier Medical Engineering (T.Y.), Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, Japan; and Funabashi Orthopaedic Hospital, Funabashi, Japan (Kenji Takahashi).
Yorikazu
Y
Akatsu
From the Department of Orthopaedic Surgery, Graduate School of Medical and Pharmaceutical Sciences (Y.Y., S.Y., T.S., T.F., Y.A., R.A., Kazuhisa Takahashi), Clinical Research Center (K.N.), and Center for Frontier Medical Engineering (T.Y.), Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, Japan; and Funabashi Orthopaedic Hospital, Funabashi, Japan (Kenji Takahashi).
Ryuichiro
R
Akagi
From the Department of Orthopaedic Surgery, Graduate School of Medical and Pharmaceutical Sciences (Y.Y., S.Y., T.S., T.F., Y.A., R.A., Kazuhisa Takahashi), Clinical Research Center (K.N.), and Center for Frontier Medical Engineering (T.Y.), Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, Japan; and Funabashi Orthopaedic Hospital, Funabashi, Japan (Kenji Takahashi).
Tadashi
T
Yamaguchi
From the Department of Orthopaedic Surgery, Graduate School of Medical and Pharmaceutical Sciences (Y.Y., S.Y., T.S., T.F., Y.A., R.A., Kazuhisa Takahashi), Clinical Research Center (K.N.), and Center for Frontier Medical Engineering (T.Y.), Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, Japan; and Funabashi Orthopaedic Hospital, Funabashi, Japan (Kenji Takahashi).
Kenji
K
Takahashi
From the Department of Orthopaedic Surgery, Graduate School of Medical and Pharmaceutical Sciences (Y.Y., S.Y., T.S., T.F., Y.A., R.A., Kazuhisa Takahashi), Clinical Research Center (K.N.), and Center for Frontier Medical Engineering (T.Y.), Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, Japan; and Funabashi Orthopaedic Hospital, Funabashi, Japan (Kenji Takahashi).
Kengo
K
Nagashima
From the Department of Orthopaedic Surgery, Graduate School of Medical and Pharmaceutical Sciences (Y.Y., S.Y., T.S., T.F., Y.A., R.A., Kazuhisa Takahashi), Clinical Research Center (K.N.), and Center for Frontier Medical Engineering (T.Y.), Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, Japan; and Funabashi Orthopaedic Hospital, Funabashi, Japan (Kenji Takahashi).
Kazuhisa
K
Takahashi
D000125:Achilles Tendon / Q000000981:diagnostic imaging / Q000293:injuries* / Q000503:physiopathology*; D000818:Animals; D055119:Elastic Modulus; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D011817:Rabbits; D015203:Reproducibility of Results; D012421:Rupture / Q000000981:diagnostic imaging / Q000503:physiopathology; D012680:Sensitivity and Specificity; D013708:Tendon Injuries / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology*; D013718:Tensile Strength; D057170:Translational Research, Biomedical; D014945:Wound Healing / Q000502:physiology