- Email: [email protected]
Reverse Achilles Tendon Allograft Technique for Anterior Cruciate Ligament Reconstruction
Technical Note
Reverse Achilles Tendon Allograft Technique for Anterior Cruciate Ligament Reconstruction David P. Zamorano, M.D., and Stuart M. Gold, M.D.
Abstract: Because of the increasing popularity of allograft anterior cruciate ligament (ACL) reconstructions, the technical difficulties with posterior bone loss in revision ACL surgery, and the limited supply of bone–patellar tendon– bone donor grafts, we have developed a technique using a reversed Achilles tendon allograft to reconstruct the ACL-deficient knee. This technique allows for bony tibial fixation with an interference screw by rotating the graft 180° and optimizing soft-tissue fixation at the femur with an EndoButton CL (Smith & Nephew, Andover, MA). Short-term follow-up (average, 26.4 weeks) of 10 patients undergoing the reversed Achilles technique has shown excellent results, with Lysholm scores between 91 and 100 and 84 and 90 in 8 of 10 and 2 of 10 patients, respectively. Objective stability assessments, including the Lachman test, anterior drawer, and pivot-shift tests, were also encouraging. Reverse Achilles tendon allografts can be excellent alternatives for ACL reconstruction when bone–patellar tendon– bone grafts are not indicated. Key Words: ACL reconstruction—Allograft—EndoButton CL.
A
llograft tendons for anterior cruciate ligament (ACL) reconstruction are becoming more popular.1 Shelton et al.2 found no functional difference between patients undergoing allograft versus autograft bone–patellar tendon– bone ACL reconstruction at 24 months’ follow-up.2 Although bone–patellar tendon– bone and Achilles tendon are the most common allografts used, there are a variety of choices that are available for the surgeon.3 Bone–patellar tendon– bone and Achilles tendon allografts both provide
From the Department of Orthopaedic Surgery, Harbor-UCLA Medical Center, Torrance, California, U.S.A. Address correspondence and reprint requests to Stuart M. Gold, M.D., Department of Orthopaedic Surgery, Harbor-UCLA Medical Center, 1000 W. Carson St, Box 422, Torrance, CA 90509, U.S.A. E-mail: [email protected] © 2005 by the Arthroscopy Association of North America Cite this article as: Zamorano DP, Gold SM. Reverse Achilles tendon allograft technique for anterior cruciate ligament reconstruction. Arthroscopy 2005;21:769.e1-769.e3 [doi:10.1016/j. arthro.2005.03.031]. 0749-8063/05/2106-4277$30.00/0 doi:10.1016/j.arthro.2005.03.031
bone-to-bone fixation, which has been shown to provide more secure fixation than soft-tissue fixation.4 We prefer bone–patellar tendon– bone allograft when indicated; however, we describe a technique for ACL reconstruction using reversed Achilles tendon allograft that we use when we believe that Achilles tendon is more appropriate. Achilles allografts allow for better length customization and are more readily available than patellar tendon allografts. Also, by reversing the Achilles allograft 180° from its usual position, we achieve bone-to-bone fixation on the tibial side which historically is the most common site of graft failure.5 Using an EndoButton CL (Smith & Nephew, Andover, MA) also provides excellent soft-tissue fixation, which has been shown to have superior failure loads to other common soft tissue fixation devices.6 The EndoButton CL also allows for secure graft fixation relying on anterior femoral cortical bone in cases of excessive posterior femoral bone loss. The sample size of the study included 10 patients (8 men and 2 women) with an average age of 33.2 years (range, 27 to 43 years) and average follow-up of 68.5 weeks (range, 15 to 127 weeks).
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 21, No 6 (June), 2005: pp 769.e1-769.e3
769.e1
769.e2
D. P. ZAMORANO AND S. M. GOLD SURGICAL TECHNIQUE
The patient is positioned in the supine position and an examination of the both knees is performed under anesthesia. All 10 cases were performed by the senior author (S.M.G.). Diagnostic arthroscopy is then performed and any pathology other than the ACL deficiency is addressed as indicated. The notch is then prepared in the standard fashion, taking care to adequately debride the ligamentum mucosum and other soft tissue that may interfere with proper positioning of the graft. Using a burr, we then proceed to do a notchplasty in order to identify the over-the-top position. A small 1.5- to 2-cm skin incision is then made over the tibia, just medial to the tibial tubercle. The periosteum is elevated and the tibial guide aimer is set at 55° and placed over the posterior aspect of the ACL footprint. Because the tendon length of our grafts is not fixed, we use a constant tibial guide aimer angle of 55° and adjust the length of the graft as needed. The guidewire is then inserted through the guide and the tibial tunnel is drilled to the appropriate size, which in our case is usually 9 or 10 mm depending on the size of the bone plug from our graft. We then turn to the femoral tunnel preparation. The 4-mm offset Endoscopic Femoral Aimer is placed in the over-the-top position. The 2.7-mm passing pin is then inserted through the anterior femoral cortex via the aimer. The 4.5-mm cannulated drill is then used to create a channel to allow passage of the EndoButton CL. The EndoButton depth gauge is used to determine the femoral channel length. Once the channel length is determined, we ream the proximal channel to create the tunnel for our graft. The depth of reaming coincides with the preferred length of intratunnel graft plus 10 mm to allow deployment of the EndoButton. The diameter of the reamer that is used to create the femoral tunnel is dependent on the diameter of the tendinous portion of our graft. It usually runs approximately 8 to 9 mm in diameter. On the back table, the Achilles tendon allograft is prepared. The calcaneal bone plug comes precontoured and sized to approximately 9 mm in diameter and 30 mm in length; however, there usually is additional contouring needed. Two drill holes are also made to pass sutures, which will allow for tensioning of the graft after insertion. The length of the graft that is needed is then determined as follows. First, we determine which size EndoButton CL we will need. This is done by measuring the length of the femoral channel and subtracting the length of the desired in-
FIGURE 1. The EndoButton CL fastened to the graft using 2 Cottony Dacron II sutures with a modified Bunnell stitch. The purple marker indicates the length of the femoral tunnel.
tratunnel graft determined by surgeon’s preference. Second, the length of the tendinous portion of the graft that is required is determined by subtracting the EndoButton length and the bone plug length from the total tunnel length (tibial tunnel length ⫹ intra-articular length ⫹ femoral channel length). We then subtract another 5 mm from the length of our tendon to ensure that the bone plug does not lie proud on the tibia. Once the length of the tendon is determined, we then trim it appropriately. The EndoButton CL is then fastened to the graft using 2 Cottony Dacron II sutures (Genzyme Corp, Fall River, MA) with a modified Bunnell stitch tied around the loop of the EndoButton (Fig 1). After the graft has been constructed, we mark the graft distal to the EndoButton, marking the femoral channel length. This provides a visual marker for when the EndoButton has cleared the anterior femoral cortex and becomes secure. The graft is now ready to be inserted. Two sutures are passed through each of the 2 holes on the EndoButton. It is important to be able to differentiate between the 2 sutures, so we use a No. 5 Ticron (USS DG, Norwalk, CT) for one suture and a No. 2 Ticron for the other. The sutures are then passed through the eyelet of the 2.7-mm passing pin, which is then inserted through the tibial and femoral tunnels and out the skin of the thigh proximally. The No. 5 suture is then pulled proximally, which will allow the EndoButton to be orientated parallel to the femoral channel and pass across the anterior femoral cortex. As the graft is advanced, the line previously marked
REVERSE ACHILLES TENDON ALLOGRAFT on the graft will become flush with the distal opening of the femoral tunnel. It is at this point that the EndoButton has completely cleared the anterior femoral cortex. The next step is to deploy the EndoButton by pulling proximally on the second suture (No. 2 Ticron). The distal sutures are then pulled to tension the graft and an interference screw (usually 8 or 9 mm) is placed in the tibia. RESULTS Three of the 10 patients underwent reconstruction within 3 months of their injury and 7 of the 10 after 3 months. Seven of the 10 patients also had meniscal pathology that was addressed at the time of reconstruction. Six of these 7 patients had arthroscopic meniscal debridement and the other underwent primary repair. One patient underwent a revision of a previous autologous bone–patellar tendon– bone graft. At final follow-up examination, 8 patients had negative Lachman test and 2 patients had 1⫹ Lachman test. One patient had a 1⫹ pivot-shift test while the other 9 patients had negative examinations. All 10 patients had achieved full range of motion relative to their uninjured knee. Eight patients had a Lysholm score ⬎90 and 2 patients had ⬎85. DISCUSSION The reversed Achilles allograft technique for ACL reconstruction seems promising in restoring
769.e3
stability to the ACL-deficient knee. Although our study was small, we feel that this previously undescribed technique can be useful in both primary and revision reconstructions. Further investigation using this technique is needed, as well as longer follow-up to assess for any delayed laxity. This technique is a useful arrow to have in a surgeon’s quiver in the treatment of the unstable ACL-deficient knee.
REFERENCES 1. Levitt RL, Malinin T, Posada A, Michalow A. Reconstruction of anterior cruciate ligaments with bone-patellar tendon-bone and achilles tendon allograft. Clin Orthop Relat Res 1994;303: 67-78. 2. Shelton WR, Papendick L, Duke AD. Autograft versus allograft ACL reconstruction. Arthroscopy 1997;13:446-449. 3. Shino K, Kimura T, Hirose H, et al. Reconstruction of the anterior cruciate ligament by allogenic tendon graft: An operation for chronic ligamentous insufficiency. J Bone Joint Surg Br 1986;68:739-746. 4. Kurosaka M, Yoshiya S, Andrish JT. A biomechanical comparison of different surgical techniques of graft fixation in anterior cruciate ligament reconstruction. Am J Sports Med 1987;15: 225-229. 5. Brown CH, Hecker AT, Hipp JA, et al. The biomechanics of interference screw fixation of patellar tendon anterior cruciate ligament grafts. Am J Sports Med 1993;21:880-886. 6. Brown CH, Sklar JH. Endoscopic anterior cruciate ligament reconstruction using quadrupled hamstring tendons and EndoButton femoral fixation. Tech Orthop 1998;13:281298.
Reverse Achilles Tendon Allograft Technique for Anterior Cruciate Ligament Reconstruction David P. Zamorano, M.D., and Stuart M. Gold, M.D.
Abstract: Because of the increasing popularity of allograft anterior cruciate ligament (ACL) reconstructions, the technical difficulties with posterior bone loss in revision ACL surgery, and the limited supply of bone–patellar tendon– bone donor grafts, we have developed a technique using a reversed Achilles tendon allograft to reconstruct the ACL-deficient knee. This technique allows for bony tibial fixation with an interference screw by rotating the graft 180° and optimizing soft-tissue fixation at the femur with an EndoButton CL (Smith & Nephew, Andover, MA). Short-term follow-up (average, 26.4 weeks) of 10 patients undergoing the reversed Achilles technique has shown excellent results, with Lysholm scores between 91 and 100 and 84 and 90 in 8 of 10 and 2 of 10 patients, respectively. Objective stability assessments, including the Lachman test, anterior drawer, and pivot-shift tests, were also encouraging. Reverse Achilles tendon allografts can be excellent alternatives for ACL reconstruction when bone–patellar tendon– bone grafts are not indicated. Key Words: ACL reconstruction—Allograft—EndoButton CL.
A
llograft tendons for anterior cruciate ligament (ACL) reconstruction are becoming more popular.1 Shelton et al.2 found no functional difference between patients undergoing allograft versus autograft bone–patellar tendon– bone ACL reconstruction at 24 months’ follow-up.2 Although bone–patellar tendon– bone and Achilles tendon are the most common allografts used, there are a variety of choices that are available for the surgeon.3 Bone–patellar tendon– bone and Achilles tendon allografts both provide
From the Department of Orthopaedic Surgery, Harbor-UCLA Medical Center, Torrance, California, U.S.A. Address correspondence and reprint requests to Stuart M. Gold, M.D., Department of Orthopaedic Surgery, Harbor-UCLA Medical Center, 1000 W. Carson St, Box 422, Torrance, CA 90509, U.S.A. E-mail: [email protected] © 2005 by the Arthroscopy Association of North America Cite this article as: Zamorano DP, Gold SM. Reverse Achilles tendon allograft technique for anterior cruciate ligament reconstruction. Arthroscopy 2005;21:769.e1-769.e3 [doi:10.1016/j. arthro.2005.03.031]. 0749-8063/05/2106-4277$30.00/0 doi:10.1016/j.arthro.2005.03.031
bone-to-bone fixation, which has been shown to provide more secure fixation than soft-tissue fixation.4 We prefer bone–patellar tendon– bone allograft when indicated; however, we describe a technique for ACL reconstruction using reversed Achilles tendon allograft that we use when we believe that Achilles tendon is more appropriate. Achilles allografts allow for better length customization and are more readily available than patellar tendon allografts. Also, by reversing the Achilles allograft 180° from its usual position, we achieve bone-to-bone fixation on the tibial side which historically is the most common site of graft failure.5 Using an EndoButton CL (Smith & Nephew, Andover, MA) also provides excellent soft-tissue fixation, which has been shown to have superior failure loads to other common soft tissue fixation devices.6 The EndoButton CL also allows for secure graft fixation relying on anterior femoral cortical bone in cases of excessive posterior femoral bone loss. The sample size of the study included 10 patients (8 men and 2 women) with an average age of 33.2 years (range, 27 to 43 years) and average follow-up of 68.5 weeks (range, 15 to 127 weeks).
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 21, No 6 (June), 2005: pp 769.e1-769.e3
769.e1
769.e2
D. P. ZAMORANO AND S. M. GOLD SURGICAL TECHNIQUE
The patient is positioned in the supine position and an examination of the both knees is performed under anesthesia. All 10 cases were performed by the senior author (S.M.G.). Diagnostic arthroscopy is then performed and any pathology other than the ACL deficiency is addressed as indicated. The notch is then prepared in the standard fashion, taking care to adequately debride the ligamentum mucosum and other soft tissue that may interfere with proper positioning of the graft. Using a burr, we then proceed to do a notchplasty in order to identify the over-the-top position. A small 1.5- to 2-cm skin incision is then made over the tibia, just medial to the tibial tubercle. The periosteum is elevated and the tibial guide aimer is set at 55° and placed over the posterior aspect of the ACL footprint. Because the tendon length of our grafts is not fixed, we use a constant tibial guide aimer angle of 55° and adjust the length of the graft as needed. The guidewire is then inserted through the guide and the tibial tunnel is drilled to the appropriate size, which in our case is usually 9 or 10 mm depending on the size of the bone plug from our graft. We then turn to the femoral tunnel preparation. The 4-mm offset Endoscopic Femoral Aimer is placed in the over-the-top position. The 2.7-mm passing pin is then inserted through the anterior femoral cortex via the aimer. The 4.5-mm cannulated drill is then used to create a channel to allow passage of the EndoButton CL. The EndoButton depth gauge is used to determine the femoral channel length. Once the channel length is determined, we ream the proximal channel to create the tunnel for our graft. The depth of reaming coincides with the preferred length of intratunnel graft plus 10 mm to allow deployment of the EndoButton. The diameter of the reamer that is used to create the femoral tunnel is dependent on the diameter of the tendinous portion of our graft. It usually runs approximately 8 to 9 mm in diameter. On the back table, the Achilles tendon allograft is prepared. The calcaneal bone plug comes precontoured and sized to approximately 9 mm in diameter and 30 mm in length; however, there usually is additional contouring needed. Two drill holes are also made to pass sutures, which will allow for tensioning of the graft after insertion. The length of the graft that is needed is then determined as follows. First, we determine which size EndoButton CL we will need. This is done by measuring the length of the femoral channel and subtracting the length of the desired in-
FIGURE 1. The EndoButton CL fastened to the graft using 2 Cottony Dacron II sutures with a modified Bunnell stitch. The purple marker indicates the length of the femoral tunnel.
tratunnel graft determined by surgeon’s preference. Second, the length of the tendinous portion of the graft that is required is determined by subtracting the EndoButton length and the bone plug length from the total tunnel length (tibial tunnel length ⫹ intra-articular length ⫹ femoral channel length). We then subtract another 5 mm from the length of our tendon to ensure that the bone plug does not lie proud on the tibia. Once the length of the tendon is determined, we then trim it appropriately. The EndoButton CL is then fastened to the graft using 2 Cottony Dacron II sutures (Genzyme Corp, Fall River, MA) with a modified Bunnell stitch tied around the loop of the EndoButton (Fig 1). After the graft has been constructed, we mark the graft distal to the EndoButton, marking the femoral channel length. This provides a visual marker for when the EndoButton has cleared the anterior femoral cortex and becomes secure. The graft is now ready to be inserted. Two sutures are passed through each of the 2 holes on the EndoButton. It is important to be able to differentiate between the 2 sutures, so we use a No. 5 Ticron (USS DG, Norwalk, CT) for one suture and a No. 2 Ticron for the other. The sutures are then passed through the eyelet of the 2.7-mm passing pin, which is then inserted through the tibial and femoral tunnels and out the skin of the thigh proximally. The No. 5 suture is then pulled proximally, which will allow the EndoButton to be orientated parallel to the femoral channel and pass across the anterior femoral cortex. As the graft is advanced, the line previously marked
REVERSE ACHILLES TENDON ALLOGRAFT on the graft will become flush with the distal opening of the femoral tunnel. It is at this point that the EndoButton has completely cleared the anterior femoral cortex. The next step is to deploy the EndoButton by pulling proximally on the second suture (No. 2 Ticron). The distal sutures are then pulled to tension the graft and an interference screw (usually 8 or 9 mm) is placed in the tibia. RESULTS Three of the 10 patients underwent reconstruction within 3 months of their injury and 7 of the 10 after 3 months. Seven of the 10 patients also had meniscal pathology that was addressed at the time of reconstruction. Six of these 7 patients had arthroscopic meniscal debridement and the other underwent primary repair. One patient underwent a revision of a previous autologous bone–patellar tendon– bone graft. At final follow-up examination, 8 patients had negative Lachman test and 2 patients had 1⫹ Lachman test. One patient had a 1⫹ pivot-shift test while the other 9 patients had negative examinations. All 10 patients had achieved full range of motion relative to their uninjured knee. Eight patients had a Lysholm score ⬎90 and 2 patients had ⬎85. DISCUSSION The reversed Achilles allograft technique for ACL reconstruction seems promising in restoring
769.e3
stability to the ACL-deficient knee. Although our study was small, we feel that this previously undescribed technique can be useful in both primary and revision reconstructions. Further investigation using this technique is needed, as well as longer follow-up to assess for any delayed laxity. This technique is a useful arrow to have in a surgeon’s quiver in the treatment of the unstable ACL-deficient knee.
REFERENCES 1. Levitt RL, Malinin T, Posada A, Michalow A. Reconstruction of anterior cruciate ligaments with bone-patellar tendon-bone and achilles tendon allograft. Clin Orthop Relat Res 1994;303: 67-78. 2. Shelton WR, Papendick L, Duke AD. Autograft versus allograft ACL reconstruction. Arthroscopy 1997;13:446-449. 3. Shino K, Kimura T, Hirose H, et al. Reconstruction of the anterior cruciate ligament by allogenic tendon graft: An operation for chronic ligamentous insufficiency. J Bone Joint Surg Br 1986;68:739-746. 4. Kurosaka M, Yoshiya S, Andrish JT. A biomechanical comparison of different surgical techniques of graft fixation in anterior cruciate ligament reconstruction. Am J Sports Med 1987;15: 225-229. 5. Brown CH, Hecker AT, Hipp JA, et al. The biomechanics of interference screw fixation of patellar tendon anterior cruciate ligament grafts. Am J Sports Med 1993;21:880-886. 6. Brown CH, Sklar JH. Endoscopic anterior cruciate ligament reconstruction using quadrupled hamstring tendons and EndoButton femoral fixation. Tech Orthop 1998;13:281298.