title: Biomechanical properties of double- and single-row suture anchor repair for surgical treatment of insertional Achilles tendinopathy.
abstract: BACKGROUND
  Because of intratendinous ossifications, retrocalcaneal bursitis, or intratendinous necrosis commonly found in insertional tendinosis, it is often necessary to detach the tendon partially or entirely from its tendon-to-bone junction.
  
  
  OBJECTIVE
  Double-row repair for insertional Achilles tendinopathy will generate an increased contact area and demonstrate higher biomechanical stability.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  Eighteen cadaver Achilles tendons were split longitudinally and detached, exposing the calcaneus; an ostectomy was performed and the tendon was reattached to the calcaneus in 1 of 2 ways: 2 suture anchors (single row) or a 4-anchor (double row) construct. Footprint area measurements over time, displacement after cyclic loading (2000 cycles), and final load to failure were measured.
  
  
  RESULTS
  The double-row refixation technique was statistically superior to the single-row technique in footprint area measurement initially and 5 minutes after repair (P = .009 and P = .01, respectively) but not after 24 hours (P = .713). The double-row construct demonstrated significantly improved measures for peak load (433.9 ± 84.3 N vs 212.0 ± 49.7 N; P = .042), load at yield (354.7 ± 106.2 N vs 198.7 ± 39.5 N; P = .01), and slope (51.8 ± 9.9 N/mm vs 66.7 ± 16.2 N/mm; P = .021). Cyclic loading did not demonstrate significant differences between the 2 constructs.
  
  
  CONCLUSIONS
  Double-row construct for reinsertion of a completely detached Achilles tendon using proximal and distal rows resulted in significantly larger contact area initially and 5 minutes after repair and led to significantly higher peak load to failure on destructive testing.
  
  
  CONCLUSIONS
  In treatment for insertional Achilles tendinosis, the tendon often has to be detached and anatomically reattached to its insertion at the calcaneus. To our knowledge there is a lack of biomechanical studies supporting either a number or a pattern of suture anchor fixation. Because the stresses going across the insertion site of the Achilles tendon are significant during rehabilitation and weightbearing activities, it is imperative to have a strong construct that allows satisfactory healing during the early postoperative process.
authors: Department of Trauma and Orthopaedic Surgery, Trauma Center Murnau, Murnau, Germany.
authors: Knut
authors: K
authors: Beitzel
authors: Augustus D
authors: AD
authors: Mazzocca
authors: Elifho
authors: E
authors: Obopilwe
authors: James W
authors: JW
authors: Boyle
authors: James
authors: J
authors: McWilliam
authors: Lina
authors: L
authors: Rincon
authors: Yasmin
authors: Y
authors: Dhar
authors: Robert A
authors: RA
authors: Arciero
authors: Annunziato
authors: A
authors: Amendola
mesh_terms: D000125:Achilles Tendon / Q000601:surgery*; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011312:Pressure; D013536:Suture Techniques; D052256:Tendinopathy / Q000601:surgery*; D016474:Weight-Bearing
keywords: biomechanics; double row; insertional Achilles tendinopathy; surgical repair; suture anchor repair