title: Surface Modification with Chemically Modified Synovial Fluid for Flexor Tendon Reconstruction in a Canine Model in Vivo.
abstract: BACKGROUND
  Functional restoration is the major concern after flexor tendon reconstruction in the hand. The purpose of the present study was to investigate the effects of modifying the surface of extrasynovial tendon autografts with carbodiimide-derivatized synovial fluid with gelatin (cd-SF-G) on functional outcomes of flexor tendon reconstruction using a canine model.
  
  
  METHODS
  The second and fifth flexor digitorum profundus tendons from eleven dogs were transected and repaired in zone II. The dogs then had six weeks of free activity leading to tendon rupture and scar formation (the repair-failure phase). In the reconstruction phase, two autologous peroneus longus tendons from each dog were harvested; one tendon was coated with cd-SF-G and the other, with saline solution, as a control. A non-weight-bearing rehabilitation protocol was followed for six weeks after reconstruction. The digits were then harvested and evaluations of function, adhesion status, gliding resistance, attachment strength, cell viability, and histology were performed.
  
  
  RESULTS
  The tendons coated with cd-SF-G demonstrated significantly lower values (mean and standard deviation) compared with the saline-solution group for work of flexion (0.63 ± 0.24 versus 1.34 ± 0.42 N-mm/deg), adhesion score (3.5 ± 1.6 versus 6.1 ± 1.3), proximal adhesion breaking force (8.6 ± 3.2 versus 20.2 ± 10.2 N), and gliding resistance (0.26 ± 0.08 versus 0.46 ± 0.22 N) (p < 0.05). There was no significant difference between the cd-SF-G and saline-solution groups (p > 0.05) in distal attachment-site strength (56.9 ± 28.4 versus 77.2 ± 36.2 N), stiffness (19 ± 7.5 versus 24.5 ± 14.5 N/mm), and compressive modulus from indentation testing (4.37 ± 1.26 versus 3.98 ± 1.24 N/mm). Histological analysis showed that tendons coated with cd-SF-G had smoother surfaces and demonstrated tendon-to-bone and tendon-to-tendon incorporation. No significant difference in viable cell count between the two groups was observed on tendon culture.
  
  
  CONCLUSIONS
  Modification of the flexor tendon surface with cd-SF-G significantly improved digital function and reduced adhesion formation without affecting graft healing and stiffness.
  
  
  CONCLUSIONS
  This study used native synovial fluid as a basic lubricating reagent to treat a tendon graft in vivo, a novel avenue for improving clinical outcomes of flexor tendon reconstruction. This methodology may also apply to other surgical procedures where postoperative adhesions impair function.
authors.affiliation: Departments of Orthopedic Surgery (X.J., R.L.R., A.R.T., L.R.B., K-N.A., P.C.A., and C.Z.) and Plastic Surgery (S.L.M.), Mayo Clinic, 200 First Street S.W., Rochester, MN 55905. E-mail address for C. Zhao: zhao.chunfeng@mayo.edu.
authors.forename: Xiaoxi
authors.initials: X
authors.lastname: Ji
authors.affiliation: Departments of Orthopedic Surgery (X.J., R.L.R., A.R.T., L.R.B., K-N.A., P.C.A., and C.Z.) and Plastic Surgery (S.L.M.), Mayo Clinic, 200 First Street S.W., Rochester, MN 55905. E-mail address for C. Zhao: zhao.chunfeng@mayo.edu.
authors.forename: Ramona L
authors.initials: RL
authors.lastname: Reisdorf
authors.affiliation: Departments of Orthopedic Surgery (X.J., R.L.R., A.R.T., L.R.B., K-N.A., P.C.A., and C.Z.) and Plastic Surgery (S.L.M.), Mayo Clinic, 200 First Street S.W., Rochester, MN 55905. E-mail address for C. Zhao: zhao.chunfeng@mayo.edu.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Thoreson
authors.affiliation: Departments of Orthopedic Surgery (X.J., R.L.R., A.R.T., L.R.B., K-N.A., P.C.A., and C.Z.) and Plastic Surgery (S.L.M.), Mayo Clinic, 200 First Street S.W., Rochester, MN 55905. E-mail address for C. Zhao: zhao.chunfeng@mayo.edu.
authors.forename: Lawrence R
authors.initials: LR
authors.lastname: Berglund
authors.affiliation: Departments of Orthopedic Surgery (X.J., R.L.R., A.R.T., L.R.B., K-N.A., P.C.A., and C.Z.) and Plastic Surgery (S.L.M.), Mayo Clinic, 200 First Street S.W., Rochester, MN 55905. E-mail address for C. Zhao: zhao.chunfeng@mayo.edu.
authors.forename: Steven L
authors.initials: SL
authors.lastname: Moran
authors.affiliation: Department of Emergency Medicine, Brown University, 593 Eddy Street, Claverick 100, Providence, RI 02903.
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Jay
authors.affiliation: Departments of Orthopedic Surgery (X.J., R.L.R., A.R.T., L.R.B., K-N.A., P.C.A., and C.Z.) and Plastic Surgery (S.L.M.), Mayo Clinic, 200 First Street S.W., Rochester, MN 55905. E-mail address for C. Zhao: zhao.chunfeng@mayo.edu.
authors.forename: Kai-Nan
authors.initials: KN
authors.lastname: An
authors.affiliation: Departments of Orthopedic Surgery (X.J., R.L.R., A.R.T., L.R.B., K-N.A., P.C.A., and C.Z.) and Plastic Surgery (S.L.M.), Mayo Clinic, 200 First Street S.W., Rochester, MN 55905. E-mail address for C. Zhao: zhao.chunfeng@mayo.edu.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Amadio
authors.affiliation: Departments of Orthopedic Surgery (X.J., R.L.R., A.R.T., L.R.B., K-N.A., P.C.A., and C.Z.) and Plastic Surgery (S.L.M.), Mayo Clinic, 200 First Street S.W., Rochester, MN 55905. E-mail address for C. Zhao: zhao.chunfeng@mayo.edu.
authors.forename: Chunfeng
authors.initials: C
authors.lastname: Zhao
mesh_terms: D000818:Animals; D002234:Carbodiimides / Q000494:pharmacology; D004285:Dogs; D005780:Gelatin; D023421:Models, Animal; D019637:Orthopedic Procedures / Q000379:methods; D013499:Surface Properties; D013582:Synovial Fluid / Q000187:drug effects; D013710:Tendons / Q000601:surgery* / Q000637:transplantation; D000267:Tissue Adhesions / Q000517:prevention & control
chemical_list: D002234:Carbodiimides; D005780:Gelatin