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Flexor Hallucis Longus and Extensor Digitorum Longus Tendon Transfers for Balancing the Foot Following Transmetatarsal Amputation
TIPS, QUIPS AND PEARLS ‘‘Tips, Quips, and Pearls’’ is a special section in The Journal of Foot & Ankle Surgery which is devoted to the sharing of ideas to make the practice of foot and ankle surgery easier. We invite our readers to share ideas with us in the form of special tips regarding diagnostic or surgical procedures, new devices or modifications of devices for making a surgical procedure a little bit easier, or virtually any other ‘‘pearl’’ that the reader believes will assist the foot and ankle surgeon in providing better care. Please address your tips to: D. Scot Malay, DPM, MSCE, FACFAS, Editor, The Journal of Foot & Ankle Surgery, PO Box 590595, San Francisco, CA 94159-0595; E-mail: [email protected]
Flexor Hallucis Longus and Extensor Digitorum Longus Tendon Transfers for Balancing the Foot Following Transmetatarsal Amputation Thomas S. Roukis, DPM, PhD, FACFAS1 Transmetatarsal amputation is a useful surgical procedure that is applicable to the treatment of the dysvascular, neuropathic, and/or traumatized forefoot. Because of the loss of the insertions of some of the extrinsic pedal musculature, transmetatarsal amputation is known to be associated with imbalance of the residual foot, and this can lead to complications related to cutaneous compromise, as well as difficulties with bracing and shoe fit. In this techniques report, we describe a combination of tendon transfers that use flexor hallucis longus and extensor digitorum longus, which can be useful in preventing pedal imbalance following transmetatarsal amputation. (The Journal of Foot & Ankle Surgery 48(3):398–401, 2009) Key Words: dysvascular foot, imbalance, Nitinol, tendon anchor, ulceration
Transmetatarsal amputations (TMA) represent commonly performed procedures useful for salvage of the diabetic foot and preservation of a functional limb. The intended goal of a TMA is to provide a stable, plantigrade, and shoeable foot Address correspondence to: Thomas S. Roukis, DPM, PhD, FACFAS, Chief, Limb Preservation Service, Vascular/Endovascular Surgery Service, Department of Surgery, Director Limb Preservation Complex Lower Extremity Surgery and Research Fellowship, Madigan Army Medical Center, 9040-A Fitzsimmons Avenue, MCHJ-SV, Tacoma, WA 98431. E-mail: [email protected]. 1 Chief, Limb Preservation Service, Vascular/Endovascular Surgery Service, Department of Surgery, Director, Limb Preservation Complex Lower Extremity Surgery and Research Fellowship, Madigan Army Medical Center, Tacoma, WA. Financial Disclosure: None reported. Conflict of Interest: None reported. Disclaimer: The opinions and assertions contained herein are the private view of the author and are not to be construed as official or reflecting the views of the Department of the Army or the Department of Defense. Published by Elsevier Inc. on behalf of the American College of Foot and Ankle Surgeons 1067-2516/09/4803-0020$36.00/0 doi:10.1053/j.jfas.2008.12.013
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that affords ambulation with a low risk of ulceration or progressive deformity (1). Through the use of split tibialis anterior tendon transfer (2, 3), peroneus brevis to peroneus longus tendon transfer (1, 4), or osseous stabilization with an intramedullary screw along the medial column of the foot, correction of a forefoot varus deformity (1, 5), which is a commonly reported complication following TMA (1–10), can be avoided at the time of the index amputation. Split tibialis anterior tendon transfer and peroneus brevis to peroneus longus tendon transfer each require additional incisions on the foot to perform them correctly, making them undesirable in the dysvascular or immunocompromised patient and also in the recently infected patient where the additional incision could be seeded with bacteria (1–4). Additionally, intramedullary screw placement can migrate, as no formal preparation of the intervening joints is performed and can potentially seed bacteria along the screw path leading to contiguous spread osteomyelitis (1, 5). In these situations the use of readily available and traditionally expendable extrinsic foot tendons to balance the TMA represents a viable option. Specifically, transfer of the flexor hallucis longus tendon
to the residual first metatarsal in conjunction with transfer of the extensor digitorum longus tendon to the residual fourth metatarsal allows for dynamic reduction of forefoot varus through plantarflexion and inversion of the medial column along with dorsiflexion and eversion of the lateral column during gait, respectively. This combination of tendon-balancing procedures has consistently resulted in a plantigrade, functional foot postoperatively, free of ulceration about the plantar lateral TMA stump as occurs with a forefoot varus posture.
Technique The equinus contracture is corrected first through an appropriate posterior lengthening procedure consisting of a percutaneous tendo-Achilles lengthening or an open gastrocnemius recession as previously described in detail (11). Following this, the TMA is performed in standard fashion except that the flexor hallucis longus and extensor digitorum longus tendons are identified, freed of surrounding soft tissue restraints, and clamped for subsequent transfer (Figure 1). A drill hole between 6 mm and 8 mm is placed through the dorsal aspect of the residual first metatarsal, approximately 10 mm proximal to the distal edge. The drill hole is angled to exit at the junction between the plantar cortex and medullary canal at the distal end of the residual first metatarsal. Just proximal to the drill hole at the dorsal cortex, another 1-mm drill hole is placed through the proximal cortex in order to accept a small suture anchor (Micro-ARIM, MMI-USA, Inc., Memphis, TN, and MemoMetal, Inc., Memphis, TN). Use of this tendon anchor, which is made of self-expanding Nitinol (Nickel Titanium Naval Ordnance Laboratory), a shape-memory alloy composed of nickel and titanium (12), allows for customized suture selection and enables the surgeon to
FIGURE 1 Intraoperative axial photograph of a transmetatarsal amputation demonstrating harvest of the flexor hallucis longus and extensor digitorum longus tendons that are shown held in metallic clamps.
choose the suture size and material that best suits the condition of the tissues. The flexor hallucis longus tendon is passed from plantar-distal through the drill hole to exit the dorsomedial forefoot, which is simultaneously plantarflexed and inverted to balance the medial aspect of the residual forefoot. With the foot held in this corrected position, the flexor hallucis longus tendon is tensioned by drawing it proximally, after which a running locking suture is weaved through the tendon using the suture needle attached to the
FIGURE 2 Intraoperative photograph of the dorsal aspect of the residual forefoot following transmetatarsal amputation demonstrating the drill hole through the residual first metatarsal (A) through which the flexor hallucis longus tendon has been transferred and secured with the small suture anchor as described in the text (B).
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FIGURE 3 Intraoperative photograph of the dorsal aspect of the residual forefoot following transmetatarsal amputation demonstrating the drill hole through the residual fourth metatarsal (A) into which the small suture anchor has been placed to allow secure transfer of the extensor digitorum longus tendon as described in the text (B).
FIGURE 4 Anterior-posterior (A) and lateral (B) non–weight-bearing radiographs following transmetatarsal amputation with tendon balancing as described in the text. Note the location of the drill hole in the residual first metatarsal, as well as the location of the small suture anchors as described in the text. Also note the proper overlapped alignment of the distal metatarsals on the lateral view indicating correction of the forefoot varus deformity.
suture anchor (Figure 2). Once properly tensioned and secured, the suture is tied and the alignment verified. Next, a 1-mm drill hole is placed approximately 10 mm from the distal edge of the residual fourth metatarsal through the dorsal cortex, and another suture anchor is placed in a fashion similar to that described above. With the lateral forefoot simultaneously dorsiflexed and everted, the extensor digitorum longus tendon slips are placed under distal traction and secured to the residual fourth metatarsal as described earlier in this article (Figure 3). At the completion of the tendon transfers, the overall alignment to the residual forefoot is reevaluated, and should reveal an even frontal plane metatarsal position that is free of forefoot varus deformity, as well as secure tendon transfers (Figure 4). Any excess length of the transferred tendons can be resected or secured to surrounding soft tissue structures with addition sutures. Layered skin closure is performed using a combination of heavy-gauge, widely spaced, nonabsorbable sutures 400
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in vertical mattress fashion interposed by skin staples over a suction drain. Summary When appropriately balanced through tendon transfer techniques and the use of a posterior soft tissue lengthening procedure, the TMA can provide a functional foot with a low likelihood of de novo or recurrent ulceration. The use of flexor hallucis longus and extensor digitorum longus tendon transfers as described in this article can effectively maintain a dynamically balanced, plantigrade, shoeable foot and, when combined with a posterior lengthening procedure, avoid development of an equinovarus deformity (Figure 5). This approach is advantageous in situations where additional incisions on the foot, or delivery of internal fixation, could result in wound-healing or infectious problems.
FIGURE 5 Clinical axial photographs of the same patient as shown in Figures 1 through 4 in the resting position (A) and during active dorsiflexion of the residual forefoot following transmetatarsal amputation (B). Note the dynamic correction of the residual forefoot varus present while at rest when the foot is actively dorsiflexed.
References 1. Schweinberger MH, Roukis TS. Soft-tissue and osseous techniques to balance forefoot and midfoot amputations. Clin Podiatr Med Surg 25(4):623–639, 2008. 2. Armstrong DG, Claxton MJ. Addressing tendon balancing concerns in diabetic patients. Podiatry Today 16(3):63–70, 2003. 3. Landsman AS, Cook E, Cook J. Tenotomy and tendon transfer about the forefoot, midfoot, and hindfoot. Clin Podiatr Med Surg 25(4):547–569, 2008. 4. Schweinberger MH, Roukis TS. Balancing of the transmetatarsal amputation with peroneus brevis to peroneus longus tendon transfer. J Foot Ankle Surg 46(6):510–514, 2007. 5. Schweinberger MH, Roukis TS. Intramedullary screw fixation for balancing of the dysvascular foot following transmetatarsal amputation. J Foot Ankle Surg 47(6):594–597, 2008.
6. Barry DC, Sabacinski KA, Habershaw GM, Giurini JM, Chrzan JS. Tendo Achillis procedures for chronic ulcerations in diabetic patients with transmetatarsal amputations. J Am Podiatr Med Assoc 83(2):96–100, 1993. 7. Reyzelman AM, Hadi S, Armstrong DG. Limb salvage with Chopart’s amputation and tendon balancing. J Am Podiatr Med Assoc 89(2): 100–103, 1999. 8. Loveland L, Reyzelman AM. Why tendon balancing is essential for amputation of the high-risk diabetic foot. Podiatry Today 13(5):53–57, 2000. 9. Grieder R, McMurray S, Claxton MJ. A guide to surgical offloading in the neuropathic foot. Podiatry Today 20(3):58–64, 2007. 10. Clark GD, Lui E, Cook KD. Tendon balancing in pedal amputations. Clin Podiatr Med Surg 22(3):447–467, 2005. 11. Schweinberger MH, Roukis TS. Surgical correction of soft-tissue ankle equinus contracture. Clin Podiatr Med Surg 25(4):571–585, 2008. 12. HP-Time.com. The alloy that remembers. TIME Magazine, Time Inc., Friday, September 13, 1968. Available at: http://www.time.com/time/ magazine/article/0, 9171, 838687,00.html. Accessed December 20, 2008.
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Flexor Hallucis Longus and Extensor Digitorum Longus Tendon Transfers for Balancing the Foot Following Transmetatarsal Amputation Thomas S. Roukis, DPM, PhD, FACFAS1 Transmetatarsal amputation is a useful surgical procedure that is applicable to the treatment of the dysvascular, neuropathic, and/or traumatized forefoot. Because of the loss of the insertions of some of the extrinsic pedal musculature, transmetatarsal amputation is known to be associated with imbalance of the residual foot, and this can lead to complications related to cutaneous compromise, as well as difficulties with bracing and shoe fit. In this techniques report, we describe a combination of tendon transfers that use flexor hallucis longus and extensor digitorum longus, which can be useful in preventing pedal imbalance following transmetatarsal amputation. (The Journal of Foot & Ankle Surgery 48(3):398–401, 2009) Key Words: dysvascular foot, imbalance, Nitinol, tendon anchor, ulceration
Transmetatarsal amputations (TMA) represent commonly performed procedures useful for salvage of the diabetic foot and preservation of a functional limb. The intended goal of a TMA is to provide a stable, plantigrade, and shoeable foot Address correspondence to: Thomas S. Roukis, DPM, PhD, FACFAS, Chief, Limb Preservation Service, Vascular/Endovascular Surgery Service, Department of Surgery, Director Limb Preservation Complex Lower Extremity Surgery and Research Fellowship, Madigan Army Medical Center, 9040-A Fitzsimmons Avenue, MCHJ-SV, Tacoma, WA 98431. E-mail: [email protected]. 1 Chief, Limb Preservation Service, Vascular/Endovascular Surgery Service, Department of Surgery, Director, Limb Preservation Complex Lower Extremity Surgery and Research Fellowship, Madigan Army Medical Center, Tacoma, WA. Financial Disclosure: None reported. Conflict of Interest: None reported. Disclaimer: The opinions and assertions contained herein are the private view of the author and are not to be construed as official or reflecting the views of the Department of the Army or the Department of Defense. Published by Elsevier Inc. on behalf of the American College of Foot and Ankle Surgeons 1067-2516/09/4803-0020$36.00/0 doi:10.1053/j.jfas.2008.12.013
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that affords ambulation with a low risk of ulceration or progressive deformity (1). Through the use of split tibialis anterior tendon transfer (2, 3), peroneus brevis to peroneus longus tendon transfer (1, 4), or osseous stabilization with an intramedullary screw along the medial column of the foot, correction of a forefoot varus deformity (1, 5), which is a commonly reported complication following TMA (1–10), can be avoided at the time of the index amputation. Split tibialis anterior tendon transfer and peroneus brevis to peroneus longus tendon transfer each require additional incisions on the foot to perform them correctly, making them undesirable in the dysvascular or immunocompromised patient and also in the recently infected patient where the additional incision could be seeded with bacteria (1–4). Additionally, intramedullary screw placement can migrate, as no formal preparation of the intervening joints is performed and can potentially seed bacteria along the screw path leading to contiguous spread osteomyelitis (1, 5). In these situations the use of readily available and traditionally expendable extrinsic foot tendons to balance the TMA represents a viable option. Specifically, transfer of the flexor hallucis longus tendon
to the residual first metatarsal in conjunction with transfer of the extensor digitorum longus tendon to the residual fourth metatarsal allows for dynamic reduction of forefoot varus through plantarflexion and inversion of the medial column along with dorsiflexion and eversion of the lateral column during gait, respectively. This combination of tendon-balancing procedures has consistently resulted in a plantigrade, functional foot postoperatively, free of ulceration about the plantar lateral TMA stump as occurs with a forefoot varus posture.
Technique The equinus contracture is corrected first through an appropriate posterior lengthening procedure consisting of a percutaneous tendo-Achilles lengthening or an open gastrocnemius recession as previously described in detail (11). Following this, the TMA is performed in standard fashion except that the flexor hallucis longus and extensor digitorum longus tendons are identified, freed of surrounding soft tissue restraints, and clamped for subsequent transfer (Figure 1). A drill hole between 6 mm and 8 mm is placed through the dorsal aspect of the residual first metatarsal, approximately 10 mm proximal to the distal edge. The drill hole is angled to exit at the junction between the plantar cortex and medullary canal at the distal end of the residual first metatarsal. Just proximal to the drill hole at the dorsal cortex, another 1-mm drill hole is placed through the proximal cortex in order to accept a small suture anchor (Micro-ARIM, MMI-USA, Inc., Memphis, TN, and MemoMetal, Inc., Memphis, TN). Use of this tendon anchor, which is made of self-expanding Nitinol (Nickel Titanium Naval Ordnance Laboratory), a shape-memory alloy composed of nickel and titanium (12), allows for customized suture selection and enables the surgeon to
FIGURE 1 Intraoperative axial photograph of a transmetatarsal amputation demonstrating harvest of the flexor hallucis longus and extensor digitorum longus tendons that are shown held in metallic clamps.
choose the suture size and material that best suits the condition of the tissues. The flexor hallucis longus tendon is passed from plantar-distal through the drill hole to exit the dorsomedial forefoot, which is simultaneously plantarflexed and inverted to balance the medial aspect of the residual forefoot. With the foot held in this corrected position, the flexor hallucis longus tendon is tensioned by drawing it proximally, after which a running locking suture is weaved through the tendon using the suture needle attached to the
FIGURE 2 Intraoperative photograph of the dorsal aspect of the residual forefoot following transmetatarsal amputation demonstrating the drill hole through the residual first metatarsal (A) through which the flexor hallucis longus tendon has been transferred and secured with the small suture anchor as described in the text (B).
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FIGURE 3 Intraoperative photograph of the dorsal aspect of the residual forefoot following transmetatarsal amputation demonstrating the drill hole through the residual fourth metatarsal (A) into which the small suture anchor has been placed to allow secure transfer of the extensor digitorum longus tendon as described in the text (B).
FIGURE 4 Anterior-posterior (A) and lateral (B) non–weight-bearing radiographs following transmetatarsal amputation with tendon balancing as described in the text. Note the location of the drill hole in the residual first metatarsal, as well as the location of the small suture anchors as described in the text. Also note the proper overlapped alignment of the distal metatarsals on the lateral view indicating correction of the forefoot varus deformity.
suture anchor (Figure 2). Once properly tensioned and secured, the suture is tied and the alignment verified. Next, a 1-mm drill hole is placed approximately 10 mm from the distal edge of the residual fourth metatarsal through the dorsal cortex, and another suture anchor is placed in a fashion similar to that described above. With the lateral forefoot simultaneously dorsiflexed and everted, the extensor digitorum longus tendon slips are placed under distal traction and secured to the residual fourth metatarsal as described earlier in this article (Figure 3). At the completion of the tendon transfers, the overall alignment to the residual forefoot is reevaluated, and should reveal an even frontal plane metatarsal position that is free of forefoot varus deformity, as well as secure tendon transfers (Figure 4). Any excess length of the transferred tendons can be resected or secured to surrounding soft tissue structures with addition sutures. Layered skin closure is performed using a combination of heavy-gauge, widely spaced, nonabsorbable sutures 400
THE JOURNAL OF FOOT & ANKLE SURGERY
in vertical mattress fashion interposed by skin staples over a suction drain. Summary When appropriately balanced through tendon transfer techniques and the use of a posterior soft tissue lengthening procedure, the TMA can provide a functional foot with a low likelihood of de novo or recurrent ulceration. The use of flexor hallucis longus and extensor digitorum longus tendon transfers as described in this article can effectively maintain a dynamically balanced, plantigrade, shoeable foot and, when combined with a posterior lengthening procedure, avoid development of an equinovarus deformity (Figure 5). This approach is advantageous in situations where additional incisions on the foot, or delivery of internal fixation, could result in wound-healing or infectious problems.
FIGURE 5 Clinical axial photographs of the same patient as shown in Figures 1 through 4 in the resting position (A) and during active dorsiflexion of the residual forefoot following transmetatarsal amputation (B). Note the dynamic correction of the residual forefoot varus present while at rest when the foot is actively dorsiflexed.
References 1. Schweinberger MH, Roukis TS. Soft-tissue and osseous techniques to balance forefoot and midfoot amputations. Clin Podiatr Med Surg 25(4):623–639, 2008. 2. Armstrong DG, Claxton MJ. Addressing tendon balancing concerns in diabetic patients. Podiatry Today 16(3):63–70, 2003. 3. Landsman AS, Cook E, Cook J. Tenotomy and tendon transfer about the forefoot, midfoot, and hindfoot. Clin Podiatr Med Surg 25(4):547–569, 2008. 4. Schweinberger MH, Roukis TS. Balancing of the transmetatarsal amputation with peroneus brevis to peroneus longus tendon transfer. J Foot Ankle Surg 46(6):510–514, 2007. 5. Schweinberger MH, Roukis TS. Intramedullary screw fixation for balancing of the dysvascular foot following transmetatarsal amputation. J Foot Ankle Surg 47(6):594–597, 2008.
6. Barry DC, Sabacinski KA, Habershaw GM, Giurini JM, Chrzan JS. Tendo Achillis procedures for chronic ulcerations in diabetic patients with transmetatarsal amputations. J Am Podiatr Med Assoc 83(2):96–100, 1993. 7. Reyzelman AM, Hadi S, Armstrong DG. Limb salvage with Chopart’s amputation and tendon balancing. J Am Podiatr Med Assoc 89(2): 100–103, 1999. 8. Loveland L, Reyzelman AM. Why tendon balancing is essential for amputation of the high-risk diabetic foot. Podiatry Today 13(5):53–57, 2000. 9. Grieder R, McMurray S, Claxton MJ. A guide to surgical offloading in the neuropathic foot. Podiatry Today 20(3):58–64, 2007. 10. Clark GD, Lui E, Cook KD. Tendon balancing in pedal amputations. Clin Podiatr Med Surg 22(3):447–467, 2005. 11. Schweinberger MH, Roukis TS. Surgical correction of soft-tissue ankle equinus contracture. Clin Podiatr Med Surg 25(4):571–585, 2008. 12. HP-Time.com. The alloy that remembers. TIME Magazine, Time Inc., Friday, September 13, 1968. Available at: http://www.time.com/time/ magazine/article/0, 9171, 838687,00.html. Accessed December 20, 2008.
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