title: Reconstruction of chronic achilles tendon rupture with the use of interposed tissue between the stumps.
abstract: BACKGROUND
  The gap between the tendon stumps in chronic Achilles tendon rupture has reportedly been filled with interposed scar tissue. In the authors' clinical experience, this interposed tissue is often thick and resists tension, so they considered it was possible to use the interposed tissue for reconstruction of Achilles tendon rupture.
  
  
  OBJECTIVE
  Scar tissue interposed between the tendon stumps has the capacity to form tendon-like repair tissue in patients with chronic Achilles tendon rupture.
  
  
  METHODS
  Case series; Level of evidence, 4.
  
  
  METHODS
  Six patients with chronic rupture of the Achilles tendon underwent tendon reconstruction with the use of interposed tissue between the stumps. The average time from the primary injury to surgery was 22 weeks (range, 9 to 30 weeks). Preoperative magnetic resonance imaging (MRI), histology of the interposed tissue, and clinical results were evaluated. The average postoperative follow-up period was 31 months (range, 24 to 43 months).
  
  
  RESULTS
  Preoperative T2-weighted MRI in all cases revealed that chronically ruptured Achilles tendons were thickened and fusiform-shaped with diffuse intratendinous high-signal alterations throughout. Longitudinal high-signal bands were seen throughout the tendon, except at the musculotendinous junction and insertion on the calcaneus. Histologically, scar tissue interposed between the tendon stumps consisted of dense collagen fibers, and degenerative changes were not seen. After surgery, no patient had difficulty in walking or stair climbing, and all were able to perform a single-limb toe raise. The mean preoperative and postoperative American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scores were 88.2 and 98.3 points, respectively; the difference was statistically significant (P = .0277).
  
  
  CONCLUSIONS
  Interposed tissue between the tendon stumps is suitable for repair of chronic Achilles tendon rupture if preoperative MRI shows a thickened fusiform-shaped Achilles tendon with diffuse intratendinous high-signal alterations throughout.
authors.affiliation: Department of Orthopedic Surgery, Osaka Medical College, Takatsuki, Osaka, Japan. ort028@poh.osaka-med.ac.jp
authors.forename: Toshito
authors.initials: T
authors.lastname: Yasuda
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Kinoshita
authors.forename: Ryuzo
authors.initials: R
authors.lastname: Okuda
mesh_terms: D000125:Achilles Tendon / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D002908:Chronic Disease; D002921:Cicatrix; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care; D011446:Prospective Studies; D019651:Plastic Surgery Procedures; D012421:Rupture / Q000601:surgery*; D013708:Tendon Injuries / Q000601:surgery*