Influence of canine recombinant somatotropin hormone on biomechanical and biochemical properties of the medial meniscus in stifles with altered stability.
OBJECTIVE
To determine biomechanical and biochemical properties of the medial meniscus in a semi-stable stifle model and in clinical patients and to determine the effect of canine recombinant somatotropin hormone (STH) on those properties.


METHODS
22 healthy adult dogs and 12 dogs with meniscal damage secondary to cranial cruciate ligament (CCL) rupture.


METHODS
The CCL was transected in 15 dogs, and stifles were immediately stabilized. Implants releasing 4 mg of STH/d were placed in 7 dogs, and 8 received sham implants. Seven dogs were used as untreated controls. Force plate analysis was performed before surgery and 2, 5, and 10 weeks after surgery. After 10 weeks, dogs were euthanatized, and menisci from surgical and contralateral stifles were harvested. The torn caudal horn of the medial meniscus in dogs with CCL rupture comprised the clinical group. Creep indentation determined aggregate modulus (HA), Poisson's ratio (v), permeability (k), and percentage recovery (%R). Water content (%W), collagen content (C), sulfated glycosaminoglycan (sGAG) content, and collagen type-I (cI) and -II (cII) immunoreactivity were also determined.


RESULTS
Surgical and clinical groups had lower HA, k, %R, C, sGAG, cI, and clI and higher %W than the non-surgical group. Surgical stifles with greater weight bearing had stiffer menisci than those bearing less weight. Collagen content was higher in the surgical group receiving STH than the surgical group without STH.


CONCLUSIONS
Acute stabilization and moderate weight bearing of the CCLdeficient stifle appear to protect stiffness of the medial meniscus. Normal appearing menisci from CCL-deficient stifles can have alterations in biomechanical and biochemical properties, which may contribute to meniscal failure.
Noone
Thomas J
TJ
Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville 37901-1071, USA.
Millis
Darryl L
DL
Korvick
Donna L
DL
Athanasiou
Kyriacos
K
Cook
James L
JL
Kuroki
Keiichi
K
Buonomo
Fran
F
D000818:Animals; D016118:Anterior Cruciate Ligament / Q000503:physiopathology / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D001696:Biomechanical Phenomena; D003094:Collagen / Q000378:metabolism; D004283:Dog Diseases / Q000188:drug therapy / Q000503:physiopathology* / Q000601:surgery; D004285:Dogs; D006025:Glycosaminoglycans / Q000378:metabolism; D013006:Growth Hormone / Q000627:therapeutic use*; D007592:Joint Diseases / Q000188:drug therapy / Q000503:physiopathology / Q000601:surgery / Q000662:veterinary*; D008592:Menisci, Tibial / Q000187:drug effects* / Q000503:physiopathology / Q000601:surgery; D011994:Recombinant Proteins / Q000627:therapeutic use; D012421:Rupture; D013264:Stifle / Q000187:drug effects* / Q000503:physiopathology / Q000601:surgery
D006025:Glycosaminoglycans; D011994:Recombinant Proteins; D013006:Growth Hormone; D003094:Collagen