Abstract
BackgroundRupture of the Achilles tendon often leads to long-term morbidity, particularly calf weakness associated with tendon elongation. Operative repair of Achilles tendon ruptures leads to reduced tendon elongation. Tendon lengthening is a key problem in the restoration of function following Achilles tendon rupture. A study was performed to determine differences in initial separation, strength and failure characteristics of differing sutures and numbers of core strands in a percutaneous Achilles tendon repair model in response to initial loading.MethodsNineteen bovine Achilles tendons were repaired using a percutaneous/minimally invasive technique with a combination of a modified Bunnell suture proximally and a Kessler suture distally, using non-absorbable 4-strand 6-strand repairs and absorbable 8-strand sutures. Specimens were then cyclically loaded using phases of 10 cycles of 100 N, 100 cycles of 100 N, 100 cycles of 190 N consistent with early range of motion training and weight-bearing, before being loaded to failure.ResultsPre-conditioning of 10 cycles of 100 N resulted in separations of 4 mm for 6-strand, 5.9 mm for 4-strand, but 11.5 mm in 8-strand repairs, this comprised 48.5, 68.6 and 72.7% of the separation that occurred after 100 cycles of 100 N. The tendon separation after the third phase of 100 cycles of 190 N was 17.4 mm for 4-strand repairs, 16.6 mm for 6-strand repairs and 26.6 mm for 8-strand repairs. There were significant differences between the groups (p < 0.0001). Four and six strand non-absorbable repairs had significantly less separation than 8-strand absorbable repairs (p = 0.017 and p = 0.04 respectively).The mean (SEM) ultimate tensile strengths were 4-strand 464.8 N (27.4), 6-strand 543.5 N (49.6) and 8-strand 422.1 N (80.5). Regression analysis reveals no significant difference between the overall strength of the 3 repair models (p = 0.32) (4 vs. 6: p = 0.30, 4 vs. 8: p = 0.87; 6 vs. 8: p = 0.39). The most common mode of failure was pull out of the Kessler suture from the distal stump in 41.7% of specimens.ConclusionThe use of a non-absorbable suture resulted in less end-to-end separation when compared to absorbable sutures when an Achilles tendon repair model was subject to cyclical loading. Ultimate failure occurred more commonly at the distal Kessler suture end although this occurred with separations in excess of clinical failure. The effect of early movement and loading on the Achilles tendon is not fully understood and requires more research.
Highlights
Rupture of the Achilles tendon often leads to long-term morbidity, calf weakness associated with tendon elongation
Operative repair of Achilles tendon ruptures leads to improved early outcome (Keating & Will, 2011), in terms of strength (Lantto et al, 2016; Willits et al, 2010) and functional activities (Olsson et al, 2011; Olsson et al, 2014) and reduced tendon elongation of 18.7 mm compared to non-operative treatment (P < 0.01) (Heikkinen et al, 2017) lengthening (5 mm at months, and 14.5 mm at years) still occurs even in augmented repairs (Heikkinen et al, 2016; Pajala et al, 2009)
Biomechanical comparison has shown that the Ma and Griffiths percutaneous technique (Ma & Grifith, 1977) has approximately 50% of the strength of open repairs and has an increased iatrogenic nerve injury rate (Chan et al, 2011; Del Buono et al, 2014; Hockenbury & Johns, 1990) this has been reduced using of absorbable sutures and visualization and protection of the nerve during surgery (Klein et al, 1991)
Summary
Rupture of the Achilles tendon often leads to long-term morbidity, calf weakness associated with tendon elongation. Rupture of the Achilles tendon leads to long-term morbidity, 10–30% calf weakness (Barfod et al, 2017; Horstmann et al, 2012; Lantto et al, 2015; Mavrodontidis et al, 2015) This weakness has been associated with tendon elongation (Silbernagel et al, 2012). The use of a combined modified Bunnell and Kessler suture configuration (Carmont & Maffulli, 2008) (Fig. 1b) using an absorbable monofilament suture shows good clinical outcome (Al-Mouazzen et al, 2005; Carmont et al, 2013) as well as specific patient subsets; athletes (Maffulli et al, 2011b), the elderly (Maffulli et al, 2010) and diabetic patients (Maffulli et al, 2011c) This suture technique has similar repair strength to that of the box suture formed using the Achillon device (Longo et al, 2012)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
