565179
research-article2014
FAIXXX10.1177/1071100714565179Foot & Ankle InternationalMiyamoto et al
Technique Tip
Fixation for Avulsion Fracture of the Calcaneal Tuberosity Using a Side-Locking Loop Suture Technique and Anti–Slip Knot
Foot & Ankle International® 2015, Vol. 36(5) 603–607 © The Author(s) 2014 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/1071100714565179 fai.sagepub.com
Wataru Miyamoto, MD1, Masato Takao, MD1, Kentaro Matsui, MD1, and Takashi Matsushita, MD1 Level of Evidence: Level V, expert opinion. Keywords: avulsion, calcaneal tuberosity, fracture, reef knot Avulsion fracture of the calcaneal tuberosity accounts for 1% to 3% of all calcaneal fractures, and its incidence peaks in women in their 70s, whose calcaneal bone strength and mineral content have decreased.2,14 Although nonoperative treatment has been recommended for fractures with less than 1 cm of displacement, operative treatment is indicated for fractures with more displacement to restore the function of the gastrocnemius-soleus complex.4,11,13 In the osteosynthesis for this type of fracture, it can be challenging to achieve sufficient fixation of the fracture fragment to resist the pull-out tension of the triceps surae because the fracture fragments are often small. The most widely accepted operative technique is the use of lag screw fixation followed by nonweightbearing in a short leg cast.3 However, a cadaveric study revealed that fixation by means of lag screws alone could resist around 250 N of tensile strength,7 which would seem to be too weak to neutralize the force of the Achilles tendon; for example, the tensile strength of the Achilles tendon when riding a bicycle is 489 to 661 N.6 Recently, the side locking-loop suture (SLLS) technique using braided polyethylene and polyester suture thread (Fiber Wire; Arthrex, Naples, FL) has been reported to provide good clinical outcomes for tendon repair.8,9,17 Also, a highly effective anti–slip knot for braided polyethylene and polyester suture thread that has satisfactory tensile strength has been introduced.12 In this article, we introduce a novel technique that provides rigid fixation of an avulsion fracture of the calcaneal tuberosity.
tendon. Then the tuberosity fracture is exposed and the displaced fragment attached to the Achilles tendon is elevated. The double SLLS technique, using 2 USP 2 braided polyethylene and polyester suture threads, is applied to the distal part of the tendon. Each suture thread is extracted from the medial and lateral sides of the tendon near its attachment to the fragment (Figure 1). By pulling the suture threads manually, the displaced fragment moves distally, and anatomical reduction is achieved with the ankle in maximal plantarflexion. The anatomically reduced position of the fragment is provisionally held by Kirschner wire fixation, and if the fracture fragment is large enough to perform screw fixation, cancellous screws of 3.5 or 4.0 mm diameter are inserted (Figure 2). A guidewire is then inserted into the calcaneal body from medial to lateral, nearly perpendicular to the axis of the lower leg, and a 4.0-mm cannulated cancellous screw of approximately the same length as the distance between the medial and lateral wall of the calcaneus is inserted through a small medial incision. Two lateral suture threads are introduced outside of the lateral skin, through the small lateral incision, which was created at the penetration point of the guidewire, and a suture retriever is passed from medial to lateral through the small incision and through the cannulated screw. At the lateral outside edge of the skin, the suture retriever grasps the 2 lateral threads and a 2-0 nylon loop, and these are extracted medially outside of the skin by pulling the device. Then 2 medial suture threads are introduced through the small medial incision, which was used to insert the cannulated cancellous screw. From
Operative Technique Surgery is conducted under general or lumbar spinal anesthesia in the prone position. A pneumatic tourniquet is applied to the thigh and inflated. A 7-cm longitudinal skin incision is made along the medial line of the Achilles tendon. After the fascia is dissected, a longitudinal incision is made on the paratenon, and it is carefully dissected from the
1
Department of Orthopaedic Surgery, Teikyo University School of Medicine, Tokyo, Japan Corresponding Author: Wataru Miyamoto, MD, Department of Orthopaedic Surgery, Teikyo University School of Medicine, 2-11-1, Kaga, Itabashi, Tokyo, 173-8605, Japan. Email: [email protected]
Downloaded from fai.sagepub.com at Bobst Library, New York University on May 17, 2015
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Foot & Ankle International 36(5)
Figure 1. (A) Schematic diagram of the side-locking loop suture (SLLS) technique. (B) Intraoperative photograph showing the double SLLS technique using 2 USP 2 braided polyethylene and polyester suture threads applied to the distal part of the Achilles tendon.
Figure 2. (A) Intraoperative photograph showing anatomical reduction of the displaced fragment by pulling the suture threads manually. (B) Schematic diagram showing screw fixation of the reduced fragment.
the skin incision, the 2 medial suture threads are put into the nylon loop, and the nylon loop is pulled from medial to lateral so that the 2 threads are extracted laterally outside of the skin. The 2 threads at each side are pulled using a mosquito forceps inserted along the medial and lateral calcaneal walls into the medial and lateral subcutaneous tissue around the calcaneus (Figure 3). Each suture thread is tied at the ventral side of the Achilles tendon using an anti–slip knot (Figure 4). Two days after surgery, partial weightbearing using a removable walking boot with the ankle joint held in plantarflexion by lifting the heel 2.5 cm is allowed. Two weeks after surgery, the sutures are removed and active
range-of-motion exercises are started. Weightbearing is gradually increased and full weightbearing is allowed 6 weeks after surgery. Use of the removal walking boot is continued for 8 weeks after surgery (Figure 5). We used the presented technique on 2 patients. Patient 1 was a 33-year-old man who injured his left heel when falling while snowboarding. He sustained a type I avulsion fracture according to the Beavis classification, accompanied by a medial malleolar fracture without displacement. Osteosynthesis of the calcaneal avulsion fracture occurred following the presented technique, and the medial malleolar fracture was fixed with 2 cannulated cancellous screws. After the operation, the postoperative protocol was
Downloaded from fai.sagepub.com at Bobst Library, New York University on May 17, 2015
605
Miyamoto et al
Figure 3. Schematic diagrams of a procedure to pass medial and lateral suture threads through the cannulated cancellous screw. (A) Two lateral suture threads are introduced through a small lateral incision. (B) The suture retriever grasps the 2 lateral threads and 2-0 nylon loop, and these are extracted medially by pulling the device. (C) Medially, the 2 medial suture threads are put into the nylon loop outside, and the nylon loop is pulled so that the 2 threads are extracted laterally. The 2 threads at each side are introduced into medial and lateral subcutaneous tissue around the calcaneus.
Figure 4. (A) Schematic diagram showing creation of an anti–slip knot at the ventral side of the Achilles tendon. First, a surgeon’s knot is made using each side of the threads. Then, both ends are made with 3 throws in the manner of a reef knot. (B) Intraoperative photograph showing fixation of the fragment using the presented technique.
followed without complications. Three months after the procedure, the patient was able to return to preinjury daily activities. Twelve months after the procedure, fracture healing was confirmed by radiography, and there was no restriction of ankle range of motion.
Patient 2 was a 74-year-old woman who sustained a type I avulsion fracture of the right heel from a fall down stairs. She underwent osteosynthesis using the presented technique. The postoperative protocol was followed without complications, and she returned to daily activity 4 months
Downloaded from fai.sagepub.com at Bobst Library, New York University on May 17, 2015
606
Foot & Ankle International 36(5)
Figure 5. (A) Preoperative lateral radiograph. (B) Lateral radiograph 1 year after surgery. In this case, fixation screws for a concomitant medial malleolar fracture were placed simultaneously.
after the procedure. Twelve months after the operation, fracture healing was confirmed by radiography, and there was no restriction of ankle range of motion.
Discussion Beavis et al2 established a classification system incorporating the 3 types of calcaneal tuberosity avulsion fractures. A type I fracture is a sleeve fracture in which a shell of cortical bone is avulsed from the posterior tuberosity.2 Type II is a beak fracture in which an oblique fracture line runs posteriorly from the most superior portion of the posterior facet.2 Type III is an infrabursal avulsion fracture from the middle third of the posterior tuberosity.2 Except for type II fractures, operative procedures for these fractures can be troublesome because lag screw fixation alone may not be sufficient when the osteoporotic bone fragments are small. In addition, the strength of internal fixation must be sufficient to resist the pull-out tension of the triceps surae. Among the techniques for avulsion fractures of the calcaneal tuberosity that have been reported, Squires et al15 advocated a technique using an oblique lateral tension band wire. In their technique, the tuberosity fragment is fixed with 2 Kirschner wires placed from superior and posterior to inferior and anterior, and a figure-of-eight tension band wire is passed around the ends of the Kirschner wires over the lateral wall of the calcaneus.15 Although they reported good operative outcomes with this technique in 5 patients without need for removal of wires, a potential complication is soft tissue irritation from the bulky knots of the tension
band wire. Some authors recommend suture anchors for this type of avulsion fracture,5,13 although fixation by such means for osteoporotic bone does not seem sufficient to resist the pull-out tension of the triceps surae. Recently, Banerjee et al1 described a technique including suture fixation through bone tunnels, where a Krackow suture was passed through the distal portion of the Achilles tendon, and each strand was passed through bone tunnels drilled in the body of the calcaneus existing on the nonweightbearing aspect of the plantar surface. The sutures were then tied through a small incision on the plantar aspect of the heel. Although their technique seems to be adequate for avulsion fractures with low-quality bone, the need for a plantar incision, which is prone to painful scar formation, is a disadvantage of this technique, as reported by the authors. The present procedure applies the SLLS technique where the locking loops are located on the side of the tendon, and this technique provides for an easy and accurate locking configuration even when the operative field is narrow.10,16 Indeed, good operative outcomes for tendon disorders by means of this technique have recently been reported.8,9,17 With regard to the strength of fixation, Komatsu et al10 reported in an experimental investigation using bovine tendons of the gastrocnemius that when the 2-stranded technique using USP 2 braided polyethylene and polyester suture thread was used for suture of a ruptured tendon, with the suture knot located between the stumps, the ultimate strength was 320.19 N, even after 10 000 times repetitive tensile loading. The presented double SLLS technique using 2 of the same suture threads appeared to have around twice
Downloaded from fai.sagepub.com at Bobst Library, New York University on May 17, 2015
607
Miyamoto et al the strength (640 N) of the single technique.10 Given that the tensile strength of the Achilles tendon when riding a bicycle is 489 to 661 N,6 the double SLLS technique makes active range-of-motion exercise possible early after surgery. If the fragment is large enough, supplemental screw fixation should be added to improve fixation strength. However, even if the fragment is too small for this, use of the double SLLS technique alone will afford sufficient fracture fixation. In addition, the anti–slip knots located on the ventral side of the Achilles tendon prevent irritation pain from the knots. Another advantage of the present technique is that reduction of the thin fragment can be achieved by pulling the suture threads distally without direct handling of the fragment using forceps, which could potentially break the fragment. Further study with a larger population that is followed over a longer term is necessary to clarify the effectiveness of the present procedure for osteosynthesis of calcaneal tuberosity avulsion fractures, as well as to verify the advantages it offers over previously reported operative procedures. Furthermore, studies investigating the pull-out strength of the presented technique performed on the calcaneus may give credence to the superior strength afforded by this technique. Declaration of Conflicting Interests The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding The author(s) received no financial support for the research, authorship, and/or publication of this article.
References 1. Banerjee R, Chao J, Sadeghi C, Taylor R, Nickisch F. Fractures of the calcaneal tuberosity treated with suture fixation through bone tunnels. J Orthop Trauma. 2011;25(11):685-690. 2. Beavis RC, Rourke K, Court-Brown C. Avulsion fracture of the calcaneal tuberosity: a case report and literature review. Foot Ankle Int. 2008;29(8):863-866. 3. Biehl WC III, Morgan JM, Wagner FW Jr, Gabriel R. Neuropathic calcaneal tuberosity avulsion fractures. Clin Orthop Relat Res. 1993;296:8-13.
4. Gardner MJ, Nork SE, Barei DP, Kramer PA, Sangeorzan BJ, Benirschke SK. Secondary soft tissue compromise in tonguetype calcaneus fractures. J Orthop Trauma. 2008;22(7): 439-445. 5. Greenhagen RM, Highlander PD, Burns PR. Double row anchor fixation: a novel technique for a diabetic calanceal insufficiency avulsion fracture. J Foot Ankle Surg. 2012;51(1):123-127. 6. Gregor RJ, Komi PV, Järvinen M. Achilles tendon forces during cycling. Int J Sports Med. 1987;8(suppl 1):9-14. 7. Hazen GE, Wilson AN, Ashfaq S, Parks BG, Schon LC. Fixation of calcaneal avulsion fractures using screws with and without suture anchors: a biomechanical investigation. Foot Ankle Int. 2007;28(11):1183-1186. 8. Imade S, Mori R, Tanaka T, Kuwata S, Uchio Y. Strong tendon repair using SLLS technique for traumatic disruption of tibialis anterior tendon and extensor hallucis longus tendon to enable early rehabilitation after surgery. Foot Ankle Int. 2011;32(10):1012-1015. 9. Imade S, Mori R, Uchio Y. Modification of side-locking loop suture technique using an antislip knot for repair of Achilles tendon rupture. J Foot Ankle Surg. 2013;52(4):553-555. 10. Komatsu F, Mori R, Uchio Y, Hatanaka H. Optimum location of knot for tendon surgery in side-locking loop technique. Clin Biomech (Bristol, Avon). 2007;22(1):112-119. 11. Lowery RB, Calhoun JH. Fractures of the calcaneus, part II: treatment. Foot Ankle Int. 1996;17(6):360-366. 12. Nishimura K, Mori R, Miyamoto W, Uchio Y. A new technique for small and secure knots using slippery polyethylene sutures. Clin Biomech (Bristol, Avon). 2009;24(4):403-406. 13. Robb CA, Davies MB. A new technique for fixation of calcaneal tuberosity avulsion fractures. Foot Ankle Surg. 2003;9(4):221-224. 14. Schepers T, Ginai AZ, Van Lieshout EM, Patka P. Demographics of extra-articular calcaneal fractures: including a review of the literature on treatment and outcome. Arch Orthop Trauma Surg. 2008;128(10):1099-1106. 15. Squires B, Allen PE, Livingstone J, Atkins RM. Fractures of the tuberosity of the calcaneus. J Bone Joint Surg Br. 2001;83(1):55-61. 16. Yotsumoto T, Mori R, Uchio Y. Optimum locations of the locking loop and knot in tendon sutures based on the locking Kessler method. J Orthop Sci. 2005;10(5):515-520. 17. Yotsumoto T, Miyamoto W, Uchio Y. Novel approach to repair of acute Achilles tendon rupture: early recovery without postoperative fixation or orthosis. Am J Sports Med. 2010;38(2):287-292.
Downloaded from fai.sagepub.com at Bobst Library, New York University on May 17, 2015
research-article2014
FAIXXX10.1177/1071100714565179Foot & Ankle InternationalMiyamoto et al
Technique Tip
Fixation for Avulsion Fracture of the Calcaneal Tuberosity Using a Side-Locking Loop Suture Technique and Anti–Slip Knot
Foot & Ankle International® 2015, Vol. 36(5) 603–607 © The Author(s) 2014 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/1071100714565179 fai.sagepub.com
Wataru Miyamoto, MD1, Masato Takao, MD1, Kentaro Matsui, MD1, and Takashi Matsushita, MD1 Level of Evidence: Level V, expert opinion. Keywords: avulsion, calcaneal tuberosity, fracture, reef knot Avulsion fracture of the calcaneal tuberosity accounts for 1% to 3% of all calcaneal fractures, and its incidence peaks in women in their 70s, whose calcaneal bone strength and mineral content have decreased.2,14 Although nonoperative treatment has been recommended for fractures with less than 1 cm of displacement, operative treatment is indicated for fractures with more displacement to restore the function of the gastrocnemius-soleus complex.4,11,13 In the osteosynthesis for this type of fracture, it can be challenging to achieve sufficient fixation of the fracture fragment to resist the pull-out tension of the triceps surae because the fracture fragments are often small. The most widely accepted operative technique is the use of lag screw fixation followed by nonweightbearing in a short leg cast.3 However, a cadaveric study revealed that fixation by means of lag screws alone could resist around 250 N of tensile strength,7 which would seem to be too weak to neutralize the force of the Achilles tendon; for example, the tensile strength of the Achilles tendon when riding a bicycle is 489 to 661 N.6 Recently, the side locking-loop suture (SLLS) technique using braided polyethylene and polyester suture thread (Fiber Wire; Arthrex, Naples, FL) has been reported to provide good clinical outcomes for tendon repair.8,9,17 Also, a highly effective anti–slip knot for braided polyethylene and polyester suture thread that has satisfactory tensile strength has been introduced.12 In this article, we introduce a novel technique that provides rigid fixation of an avulsion fracture of the calcaneal tuberosity.
tendon. Then the tuberosity fracture is exposed and the displaced fragment attached to the Achilles tendon is elevated. The double SLLS technique, using 2 USP 2 braided polyethylene and polyester suture threads, is applied to the distal part of the tendon. Each suture thread is extracted from the medial and lateral sides of the tendon near its attachment to the fragment (Figure 1). By pulling the suture threads manually, the displaced fragment moves distally, and anatomical reduction is achieved with the ankle in maximal plantarflexion. The anatomically reduced position of the fragment is provisionally held by Kirschner wire fixation, and if the fracture fragment is large enough to perform screw fixation, cancellous screws of 3.5 or 4.0 mm diameter are inserted (Figure 2). A guidewire is then inserted into the calcaneal body from medial to lateral, nearly perpendicular to the axis of the lower leg, and a 4.0-mm cannulated cancellous screw of approximately the same length as the distance between the medial and lateral wall of the calcaneus is inserted through a small medial incision. Two lateral suture threads are introduced outside of the lateral skin, through the small lateral incision, which was created at the penetration point of the guidewire, and a suture retriever is passed from medial to lateral through the small incision and through the cannulated screw. At the lateral outside edge of the skin, the suture retriever grasps the 2 lateral threads and a 2-0 nylon loop, and these are extracted medially outside of the skin by pulling the device. Then 2 medial suture threads are introduced through the small medial incision, which was used to insert the cannulated cancellous screw. From
Operative Technique Surgery is conducted under general or lumbar spinal anesthesia in the prone position. A pneumatic tourniquet is applied to the thigh and inflated. A 7-cm longitudinal skin incision is made along the medial line of the Achilles tendon. After the fascia is dissected, a longitudinal incision is made on the paratenon, and it is carefully dissected from the
1
Department of Orthopaedic Surgery, Teikyo University School of Medicine, Tokyo, Japan Corresponding Author: Wataru Miyamoto, MD, Department of Orthopaedic Surgery, Teikyo University School of Medicine, 2-11-1, Kaga, Itabashi, Tokyo, 173-8605, Japan. Email: [email protected]
Downloaded from fai.sagepub.com at Bobst Library, New York University on May 17, 2015
604
Foot & Ankle International 36(5)
Figure 1. (A) Schematic diagram of the side-locking loop suture (SLLS) technique. (B) Intraoperative photograph showing the double SLLS technique using 2 USP 2 braided polyethylene and polyester suture threads applied to the distal part of the Achilles tendon.
Figure 2. (A) Intraoperative photograph showing anatomical reduction of the displaced fragment by pulling the suture threads manually. (B) Schematic diagram showing screw fixation of the reduced fragment.
the skin incision, the 2 medial suture threads are put into the nylon loop, and the nylon loop is pulled from medial to lateral so that the 2 threads are extracted laterally outside of the skin. The 2 threads at each side are pulled using a mosquito forceps inserted along the medial and lateral calcaneal walls into the medial and lateral subcutaneous tissue around the calcaneus (Figure 3). Each suture thread is tied at the ventral side of the Achilles tendon using an anti–slip knot (Figure 4). Two days after surgery, partial weightbearing using a removable walking boot with the ankle joint held in plantarflexion by lifting the heel 2.5 cm is allowed. Two weeks after surgery, the sutures are removed and active
range-of-motion exercises are started. Weightbearing is gradually increased and full weightbearing is allowed 6 weeks after surgery. Use of the removal walking boot is continued for 8 weeks after surgery (Figure 5). We used the presented technique on 2 patients. Patient 1 was a 33-year-old man who injured his left heel when falling while snowboarding. He sustained a type I avulsion fracture according to the Beavis classification, accompanied by a medial malleolar fracture without displacement. Osteosynthesis of the calcaneal avulsion fracture occurred following the presented technique, and the medial malleolar fracture was fixed with 2 cannulated cancellous screws. After the operation, the postoperative protocol was
Downloaded from fai.sagepub.com at Bobst Library, New York University on May 17, 2015
605
Miyamoto et al
Figure 3. Schematic diagrams of a procedure to pass medial and lateral suture threads through the cannulated cancellous screw. (A) Two lateral suture threads are introduced through a small lateral incision. (B) The suture retriever grasps the 2 lateral threads and 2-0 nylon loop, and these are extracted medially by pulling the device. (C) Medially, the 2 medial suture threads are put into the nylon loop outside, and the nylon loop is pulled so that the 2 threads are extracted laterally. The 2 threads at each side are introduced into medial and lateral subcutaneous tissue around the calcaneus.
Figure 4. (A) Schematic diagram showing creation of an anti–slip knot at the ventral side of the Achilles tendon. First, a surgeon’s knot is made using each side of the threads. Then, both ends are made with 3 throws in the manner of a reef knot. (B) Intraoperative photograph showing fixation of the fragment using the presented technique.
followed without complications. Three months after the procedure, the patient was able to return to preinjury daily activities. Twelve months after the procedure, fracture healing was confirmed by radiography, and there was no restriction of ankle range of motion.
Patient 2 was a 74-year-old woman who sustained a type I avulsion fracture of the right heel from a fall down stairs. She underwent osteosynthesis using the presented technique. The postoperative protocol was followed without complications, and she returned to daily activity 4 months
Downloaded from fai.sagepub.com at Bobst Library, New York University on May 17, 2015
606
Foot & Ankle International 36(5)
Figure 5. (A) Preoperative lateral radiograph. (B) Lateral radiograph 1 year after surgery. In this case, fixation screws for a concomitant medial malleolar fracture were placed simultaneously.
after the procedure. Twelve months after the operation, fracture healing was confirmed by radiography, and there was no restriction of ankle range of motion.
Discussion Beavis et al2 established a classification system incorporating the 3 types of calcaneal tuberosity avulsion fractures. A type I fracture is a sleeve fracture in which a shell of cortical bone is avulsed from the posterior tuberosity.2 Type II is a beak fracture in which an oblique fracture line runs posteriorly from the most superior portion of the posterior facet.2 Type III is an infrabursal avulsion fracture from the middle third of the posterior tuberosity.2 Except for type II fractures, operative procedures for these fractures can be troublesome because lag screw fixation alone may not be sufficient when the osteoporotic bone fragments are small. In addition, the strength of internal fixation must be sufficient to resist the pull-out tension of the triceps surae. Among the techniques for avulsion fractures of the calcaneal tuberosity that have been reported, Squires et al15 advocated a technique using an oblique lateral tension band wire. In their technique, the tuberosity fragment is fixed with 2 Kirschner wires placed from superior and posterior to inferior and anterior, and a figure-of-eight tension band wire is passed around the ends of the Kirschner wires over the lateral wall of the calcaneus.15 Although they reported good operative outcomes with this technique in 5 patients without need for removal of wires, a potential complication is soft tissue irritation from the bulky knots of the tension
band wire. Some authors recommend suture anchors for this type of avulsion fracture,5,13 although fixation by such means for osteoporotic bone does not seem sufficient to resist the pull-out tension of the triceps surae. Recently, Banerjee et al1 described a technique including suture fixation through bone tunnels, where a Krackow suture was passed through the distal portion of the Achilles tendon, and each strand was passed through bone tunnels drilled in the body of the calcaneus existing on the nonweightbearing aspect of the plantar surface. The sutures were then tied through a small incision on the plantar aspect of the heel. Although their technique seems to be adequate for avulsion fractures with low-quality bone, the need for a plantar incision, which is prone to painful scar formation, is a disadvantage of this technique, as reported by the authors. The present procedure applies the SLLS technique where the locking loops are located on the side of the tendon, and this technique provides for an easy and accurate locking configuration even when the operative field is narrow.10,16 Indeed, good operative outcomes for tendon disorders by means of this technique have recently been reported.8,9,17 With regard to the strength of fixation, Komatsu et al10 reported in an experimental investigation using bovine tendons of the gastrocnemius that when the 2-stranded technique using USP 2 braided polyethylene and polyester suture thread was used for suture of a ruptured tendon, with the suture knot located between the stumps, the ultimate strength was 320.19 N, even after 10 000 times repetitive tensile loading. The presented double SLLS technique using 2 of the same suture threads appeared to have around twice
Downloaded from fai.sagepub.com at Bobst Library, New York University on May 17, 2015
607
Miyamoto et al the strength (640 N) of the single technique.10 Given that the tensile strength of the Achilles tendon when riding a bicycle is 489 to 661 N,6 the double SLLS technique makes active range-of-motion exercise possible early after surgery. If the fragment is large enough, supplemental screw fixation should be added to improve fixation strength. However, even if the fragment is too small for this, use of the double SLLS technique alone will afford sufficient fracture fixation. In addition, the anti–slip knots located on the ventral side of the Achilles tendon prevent irritation pain from the knots. Another advantage of the present technique is that reduction of the thin fragment can be achieved by pulling the suture threads distally without direct handling of the fragment using forceps, which could potentially break the fragment. Further study with a larger population that is followed over a longer term is necessary to clarify the effectiveness of the present procedure for osteosynthesis of calcaneal tuberosity avulsion fractures, as well as to verify the advantages it offers over previously reported operative procedures. Furthermore, studies investigating the pull-out strength of the presented technique performed on the calcaneus may give credence to the superior strength afforded by this technique. Declaration of Conflicting Interests The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding The author(s) received no financial support for the research, authorship, and/or publication of this article.
References 1. Banerjee R, Chao J, Sadeghi C, Taylor R, Nickisch F. Fractures of the calcaneal tuberosity treated with suture fixation through bone tunnels. J Orthop Trauma. 2011;25(11):685-690. 2. Beavis RC, Rourke K, Court-Brown C. Avulsion fracture of the calcaneal tuberosity: a case report and literature review. Foot Ankle Int. 2008;29(8):863-866. 3. Biehl WC III, Morgan JM, Wagner FW Jr, Gabriel R. Neuropathic calcaneal tuberosity avulsion fractures. Clin Orthop Relat Res. 1993;296:8-13.
4. Gardner MJ, Nork SE, Barei DP, Kramer PA, Sangeorzan BJ, Benirschke SK. Secondary soft tissue compromise in tonguetype calcaneus fractures. J Orthop Trauma. 2008;22(7): 439-445. 5. Greenhagen RM, Highlander PD, Burns PR. Double row anchor fixation: a novel technique for a diabetic calanceal insufficiency avulsion fracture. J Foot Ankle Surg. 2012;51(1):123-127. 6. Gregor RJ, Komi PV, Järvinen M. Achilles tendon forces during cycling. Int J Sports Med. 1987;8(suppl 1):9-14. 7. Hazen GE, Wilson AN, Ashfaq S, Parks BG, Schon LC. Fixation of calcaneal avulsion fractures using screws with and without suture anchors: a biomechanical investigation. Foot Ankle Int. 2007;28(11):1183-1186. 8. Imade S, Mori R, Tanaka T, Kuwata S, Uchio Y. Strong tendon repair using SLLS technique for traumatic disruption of tibialis anterior tendon and extensor hallucis longus tendon to enable early rehabilitation after surgery. Foot Ankle Int. 2011;32(10):1012-1015. 9. Imade S, Mori R, Uchio Y. Modification of side-locking loop suture technique using an antislip knot for repair of Achilles tendon rupture. J Foot Ankle Surg. 2013;52(4):553-555. 10. Komatsu F, Mori R, Uchio Y, Hatanaka H. Optimum location of knot for tendon surgery in side-locking loop technique. Clin Biomech (Bristol, Avon). 2007;22(1):112-119. 11. Lowery RB, Calhoun JH. Fractures of the calcaneus, part II: treatment. Foot Ankle Int. 1996;17(6):360-366. 12. Nishimura K, Mori R, Miyamoto W, Uchio Y. A new technique for small and secure knots using slippery polyethylene sutures. Clin Biomech (Bristol, Avon). 2009;24(4):403-406. 13. Robb CA, Davies MB. A new technique for fixation of calcaneal tuberosity avulsion fractures. Foot Ankle Surg. 2003;9(4):221-224. 14. Schepers T, Ginai AZ, Van Lieshout EM, Patka P. Demographics of extra-articular calcaneal fractures: including a review of the literature on treatment and outcome. Arch Orthop Trauma Surg. 2008;128(10):1099-1106. 15. Squires B, Allen PE, Livingstone J, Atkins RM. Fractures of the tuberosity of the calcaneus. J Bone Joint Surg Br. 2001;83(1):55-61. 16. Yotsumoto T, Mori R, Uchio Y. Optimum locations of the locking loop and knot in tendon sutures based on the locking Kessler method. J Orthop Sci. 2005;10(5):515-520. 17. Yotsumoto T, Miyamoto W, Uchio Y. Novel approach to repair of acute Achilles tendon rupture: early recovery without postoperative fixation or orthosis. Am J Sports Med. 2010;38(2):287-292.
Downloaded from fai.sagepub.com at Bobst Library, New York University on May 17, 2015
