Open Anatomic Reconstruction of the Medial Collateral Ligament and Posteromedial Corner Matthew R. Prince, D.O., Andrew J. Blackman, M.D., Alexander H. King, B.S., Michael J. Stuart, M.D., and Bruce A. Levy, M.D.
Abstract: Injuries to the medial collateral ligament (MCL) and posteromedial corner can occur in isolation or in the setting of multiligamentous knee injuries. Reconstruction of the MCL and posteromedial corner is indicated in the setting of a multiligamentous knee injury. Isolated cases failing nonoperative treatment may also undergo surgical treatment. Our preferred technique for anatomic medial-sided knee reconstruction is an open anatomic MCL reconstruction using an Achilles tendon allograft along with direct repair of all associated medial and posteromedial structures.
T
he superficial medial collateral ligament (MCL) and its complementary medial structures, including the deep MCL, posterior oblique ligament (POL), and semimembranosus, are the key components providing valgus stability to the knee. Medial-sided injuries involving the superficial MCL constitute the most common ligamentous injury of the knee.1 The superficial MCL femoral origin is located 3.2 mm proximal and 4.8 mm posterior to the medial epicondyle. The ligament inserts distally on the tibia at 2 points, approximately 12.2 mm and 61.2 mm distal to the joint line (Fig 1).2 MCL injury severity is categorized as grade 1, grade 2, and grade 3 based on asymmetrical medial joint space opening to valgus stress of 2 to 5 mm, 6 to 10 mm, and greater than 10 mm, respectively.3 Excellent results after nonoperative treatment of all 3 grades of MCL injury have been reported.4,5 Nonoperative treatment results are inferior in the setting of multiligament injury, valgus knee alignment, and associated injury to the POL, deep MCL, and semimembranosus tendon.3,6,7 Healing
From the Department of Orthopedic Surgery and Sports Medicine, Mayo Clinic, Rochester, Minnesota, U.S.A. The authors report the following potential conflict of interest or source of funding: A.J.B. and M.J.S. receive support from Arthrex, Stryker, and USA Hockey Foundation. B.A.L. receives support from Clinical Orthopaedics and Related Research, Arthrex, National Institutes of Health, and VOT Solutions. Received May 7, 2015; accepted August 25, 2015. Address correspondence to Bruce A. Levy, M.D., Department of Orthopedic Surgery, Mayo Clinic, 200 First St SW, Rochester, MN 55905, U.S.A. E-mail: [email protected] Ó 2016 by the Arthroscopy Association of North America 2212-6287/15434/$36.00 http://dx.doi.org/10.1016/j.eats.2015.08.013
potential may also be impaired when a distal tibial MCL avulsion is associated with interposition of the pes tendons (the so-called Stener lesion of the knee).8 The decision to address the posteromedial corner (PMC) is determined by the anteromedial drawer test. Asymmetry of greater than 10 to 15 indicates disruption of the PMC. This test is similar to an external rotation drawer test except that with anteromedial rotatory instability, the tibia externally rotates and the medial tibial step-off increases as opposed to decreases as seen in posterolateral corner injuries. In addition, valgus instability of greater than 10 in full extension indicates disruption of the MCL, PMC, and cruciate ligaments (Fig 2). When surgical intervention is indicated, our preferred technique is an open anatomic MCL reconstruction using an Achilles tendon allograft along with direct repair of all associated medial and posteromedial structures (Table 1, Video 1).
Graft Selection A fresh-frozen, nonirradiated Achilles tendon allograft (Musculoskeletal Transplant Foundation, Edison, NJ) with a 9 20emm calcaneal bone block is prepared.
Patient Positioning The patient is initially positioned supine with the foot of the bed down using a standard leg holder to facilitate concomitant cruciate ligament reconstruction, if necessary. The foot of the table is then raised, and a foam ramp (Bone Foam, Plymouth, MN) and new sterile drape are placed under the operative leg for the subsequent medial-sided reconstruction. Alternatively, the foot of the table can be left raised, and the cruciate
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Fig 2. Fluoroscopic image of a right knee showing significant valgus stress. The medial joint space is significantly widened (arrow), consistent with a combined medial collateral ligament and posteromedial corner injury.
Fig 1. Drawing by LaPrade et al.2 showing the relevant anatomic landmarks of the posteromedial corner insertions on the femur and superficial and deep medial collateral ligament insertions on the tibia. It is important to appreciate the femoral insertion of the superficial medial collateral ligament (sMCL) just posterior and proximal to the medial epicondyle (ME), along with its 2 tibial insertions 12.2 mm and 61.2 mm distal to the joint line. One should also note the meniscofemoral and meniscotibial ligament insertions of the deep medial collateral ligament. The posterior oblique ligament (POL) is shown at its average distance of 7.7 mm distal and 6.4 mm posterior to the adductor tubercle (AT) and 1.4 mm distal and 2.9 mm anterior to the gastrocnemius tubercle (GT). Lastly, the medial patellofemoral ligament (MPFL) and adductor magnus tendon (AMT) are shown. Reprinted with permission.2 (MGT, medial gastrocnemius tendon.)
ligament reconstruction can be performed with the foot secured with an adjustable holder, alleviating the need to redrape.
Surgical Technique The surgical approach for a medial-sided reconstruction is planned according to concomitant pathology. A longitudinal, anteromedial incision with a full-thickness
medial skin flap is used when additional medial or posteromedial pathology is present, such as in the case of a medial meniscus tear requiring repair or PMC disruption. Two smaller incisions over the femoral and tibial MCL attachment sites can be used for an isolated MCL reconstruction. The distal tibial insertion is exposed first. A 4-cm incision is made approximately 1 cm medial to the tibial tubercle, allowing exposure distal and proximal to the superficial MCL insertion sites. The sartorius fascia is incised, and the pes tendons are retracted distally, exposing the MCL insertion, approximately 6 cm from the joint line.2 The distal insertion point should be recreated just anterior to the posterior border of the tibia, with the surgeon leaving just enough room so that
Table 1. Indications and Contraindications of MCL Reconstruction Indications Multiligament knee injury Injury to associated structures (i.e., POL, semimembranosus, and deep MCL) Chronic valgus instability Contraindications Isolated MCL injury with potential to heal with conservative management Acute repairable injury MCL, medial collateral ligament; POL, posterior oblique ligament.
MEDIAL COLLATERAL LIGAMENT RECONSTRUCTION
the 18-mm spiked washer (Arthrex, Naples, FL), used for fixation, does not overlap the posterior border (Fig 3). This area is exposed subperiosteally. Then, the femoral insertion is exposed by making a longitudinal incision over the medial epicondyle down to the crural fascia. Fluoroscopy helps to localize the origin of the superficial MCL, which averages 3.2 mm proximal and 4.8 mm posterior to the medial epicondyle.9,10 Once this landmark is identified, damage to the medial supporting structures, including the adductor magnus tendon, medial head of the gastrocnemius, POL, semimembranosus, and posteromedial capsule, is evaluated. All injured structures are repaired at this time, with the exception of the posteromedial capsule. This is accomplished by placing pre-loaded 2.8-mm metal SutureTak suture anchors (Arthrex) along the posterior aspect of the medial femoral condyle. A longitudinal split posterior to the MCL insertion creates a tissue flap posteriorly containing the posteromedial capsule and POL that may be imbricated after the MCL reconstruction is performed. Isometry of the MCL reconstruction is evaluated by inserting a 2.4-mm guide pin into both the femoral and tibial MCL insertion points and then placing a Mersilene tape (Ethicon, Cincinnati, OH) around the 2 pins. A blue marking pen is used to mark the tape at the 2 insertion sites where the pins enter the bone. The knee is flexed and extended to determine if adjustments are necessary at the femoral pin site to ensure isometric positioning (Fig 4). If the blue mark on the tape lengthens in flexion (i.e., tight in flexion), the femoral pin is repositioned posteriorly by a few millimeters at a time until isometry is achieved (Fig 5). Finding isometry can also be achieved using intraoperative fluoroscopy as described by Wijdicks et al.9 Once isometry is confirmed, a 9 25emm socket is created over the femoral pin, the socket is tapped with a 9-mm tap, and the calcaneal bone plug is fixed with a 7 25emm BioComposite interference screw (Arthrex) (Fig 6). Two suture anchors are placed 12 mm distal to the joint
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Fig 4. Testing isometry with 2.4-mm guide pins (arrows) placed at the femoral and distal tibial superficial medial collateral ligament attachment sites.
line to re-create the proximal tibial insertion. Fluoroscopy may also be useful for this step to ensure that the anchors are placed posterior enough to be in line with the distal insertion site. The graft is passed deep to the sartorial fascia. A small split is made in the graft for the screw at the distal insertion site. A No. 2 nonabsorbable suture is placed in whipstitch fashion up and down 3 cm from the split. At the distal tibial insertion site, a 3.2mm bicortical drill hole is created. The graft is secured to the tibia with a 4.5-mm bicortical screw (Arthrex) and 18-mm spiked washer (Arthrex) at 20 of knee flexion while a varus stress is applied (Fig 7). Secondary fixation is achieved by tying the graft sutures around the screw and washer. The proximal tibial insertion is re-created by tying the sutures from the previously placed 2.8-mm SutureTak suture anchors in a mattress fashion through the graft (Fig 8). Lastly, the posteromedial capsuleePOL complex is repaired or imbricated by placing 2 to 3 suture anchors at the posterior margin of the medial femoral condyle just distal and anterior to the gastrocnemius tubercle. Mattress sutures are placed into the capsular and POL tissue and then tied in full extension to effect the repair. If the sutures in the capsule are tied in flexion, full extension may not be achieved. The capsule is closed with No. 0 braided absorbable sutures. Accurate hardware placement is confirmed with fluoroscopy (Table 2).
Postoperative Course
Fig 3. Electrocautery (arrow) is used to mark the fixation point at the distal tibial superficial medial collateral ligament insertion site, just off the posterior border of the tibia, 6 to 7 cm distal from the medial joint line.
The specific rehabilitation protocol depends on concomitant procedures performed along with the MCL reconstruction. In general, a hinged brace with a slight varus mold is used for the first 6 weeks. The brace is locked in extension with toe-touch weight bearing during ambulation and unlocked for knee range-ofmotion exercises. After 6 weeks, progressive weight bearing is allowed with the brace unlocked. At 12 weeks, the patient can bear full weight while wearing a custom varus-molded knee brace.
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Fig 5. Wijdicks et al.9 described the radiographic landmarks defining the femoral insertion of the superficial medial collateral ligament (sMCL). Line 1 is an extension of the posterior femoral cortex, and line 2 is drawn perpendicular to line 1, intersecting the most posterior aspect of the Blumensaat line. The femoral attachment of the sMCL was found to be, on average, 8.6 mm anterior to the posterior femoral cortex line and 11.0 mm distal to the intersection of the posterior femoral cortex line (line 1) and the line intersecting the posterior aspect of the Blumensaat line (line 2). Reprinted with permission.9 (A, adductor tubercle; B, MPFL; C, gastrocnemius tubercle; D, POL; E, sMCL; F, medial epicondyle; MPFL, medial patellofemoral ligament; POL, posterior oblique ligament.)
Discussion Injuries to the MCL are common, but most can be treated successfully by nonoperative functional rehabilitation protocols. Accepted surgical techniques for treatment of MCL injuries include various reconstruction techniques, such as that described in this report, and direct ligament repair. A recent review of the literature by DeLong and Waterman11 described numerous variations in MCL reconstruction techniques, with a lack of high-quality literature comparing these techniques.
Currently, there is a paucity of literature comparing repair versus reconstruction of the MCL. Kovachevich et al.12 found satisfactory results for both repair and reconstruction. They emphasized the fact that the existing literature lacks the homogeneity of classification systems, clearly defined objective outcome scores, high levels of evidence, and direct comparison of treatment methods to make recommendations on the superiority of either technique.12 Higher failure rates have been shown with lateral-sided repairs versus reconstruction in the multiligament-injured knee.13,14
Fig 6. The 9 25emm femoral socket is reamed and tapped, and the calcaneal bone plug is fixed in place with a 7 25emm BioComposite interference screw. Arrow shows the tap for femoral socket.
Fig 7. The distal tibial superficial medial collateral ligament attachment is secured with a 4.5-mm bicortical screw and 18mm spiked washer at 20 of knee flexion while a varus stress is applied. Arrow points to the screw and washer.
MEDIAL COLLATERAL LIGAMENT RECONSTRUCTION
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Table 3. Advantages and Disadvantages of MCL Reconstruction Advantages Straightforward technique Bone-to-bone healing at femur Broad tendon coverage at tibia, similar to native MCL Disadvantages Need for allograft Possible hardware irritation MCL, medial collateral ligament.
Fig 8. Anteroposterior radiographic image of proximal tibial superficial medial collateral ligament attachment re-created with 2.8-mm metal SutureTak anchors. The arrows demonstrate proper placement of the proximal tibial SutureTak anchors.
Similar findings have been shown for medial-sided injuries in this setting. Stannard et al.15 reported on 73 knee dislocations that required MCL-PMC repair or reconstruction. In this nonrandomized, comparative, prospective study, the repair group had a failure rate of 20% whereas the reconstruction group had a failure rate of only 4%. This difference was highly significant. In a systematic review of MCL repair, DeLong and Waterman16 highlighted the fact that MCL repair remains a relevant treatment choice in cases of acute MCL injury but should be used with caution in cases of chronic MCL deficiency. When operative treatment is indicated, we prefer a medial-sided repair with an anatomic MCL reconstruction using Achilles tendon allograft. Two studies using an almost identical technique for MCL reconstruction with medium-term follow-up reported ligamentous stability and reliable subjective clinical outcomes.17,18 This technique is technically straightforward, easily reproducible, and clinically reliable. It has the advantage of bone-to-bone healing at the femur and broad tendon coverage at the tibia, similar to the native MCL insertion. The disadvantage of this technique is that it requires an allograft. In addition, Table 2. Technique Pearls and Pitfalls of MCL Reconstruction Pearls Use fluoroscopy to mark the femoral incision, which is often more posterior than expected. Be sure to identify the posterior border of the tibia for the distal superficial MCL insertion. Be sure the ends of the whipstitch exit the inferior aspect of the distal tendon. Pitfalls Not fully seating the bone plug in the femoral socket before placing the interference screw Not checking isometry before creating the femoral socket Not re-creating both the distal and proximal superficial MCL attachments MCL, medial collateral ligament.
although very rare because of the low-profile design of the screw and washer, there is the possibility of hardware irritation (Table 3).
References 1. Wijdicks CA, Griffith CJ, Johansen S, Engebretsen L, LaPrade RF. Injuries to the medial collateral ligament and associated medial structures of the knee. J Bone Joint Surg Am 2010;92:1266-1280. 2. LaPrade RF, Engebretsen AH, Ly TV, Johansen S, Wentorf FA, Engebretsen L. The anatomy of the medial part of the knee. J Bone Joint Surg Am 2007;89:2000-2010. 3. Phisitkul P, James SL, Wolf BR, Amendola A. MCL injuries of the knee: Current concepts review. Iowa Orthop J 2006;26:77-90. 4. Petermann J, von Garrel T, Gotzen L. Non-operative treatment of acute medial collateral ligament lesions of the knee joint. Knee Surg Sports Traumatol Arthrosc 1993;1:93-96. 5. Holden DL, Eggert AW, Butler JE. The nonoperative treatment of grade I and II medial collateral ligament injuries to the knee. Am J Sports Med 1983;11:340-344. 6. Woo SL, Vogrin TM, Abramowitch SD. Healing and repair of ligament injuries in the knee. J Am Acad Orthop Surg 2000;8:364-372. 7. Anderson DR, Weiss JA, Takai S, Ohland KJ, Woo SL. Healing of the medial collateral ligament following a triad injury: A biomechanical and histological study of the knee in rabbits. J Orthop Res 1992;10:485-495. 8. Bollier M, Smith PA. Anterior cruciate ligament and medial collateral ligament injuries. J Knee Surg 2014;27: 359-368. 9. Wijdicks CA, Griffith CJ, LaPrade RF, et al. Radiographic identification of the primary medial knee structures. J Bone Joint Surg Am 2009;91:521-529. 10. Leiter JR, Levy BA, Stannard JP, et al. Accuracy and reliability of determining the isometric point of the knee for multiligament knee reconstruction. Knee Surg Sports Traumatol Arthrosc 2014;22:2187-2193. 11. DeLong JM, Waterman BR. Surgical techniques for the reconstruction of medial collateral ligament and posteromedial corner injuries of the knee: A systematic review. Arthroscopy 2015;31:2258-2272. e1. 12. Kovachevich R, Shah JP, Arens AM, Stuart MJ, Dahm DL, Levy BA. Operative management of the medial collateral ligament in the multi-ligament injured knee: An evidence-based systematic review. Knee Surg Sports Traumatol Arthrosc 2009;17:823-829.
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13. Levy BA, Dajani KA, Morgan JA, Shah JP, Dahm DL, Stuart MJ. Repair versus reconstruction of the fibular collateral ligament and posterolateral corner in the multiligamentinjured knee. Am J Sports Med 2010;38:804-809. 14. Stannard JP, Brown SL, Farris RC, McGwin G Jr, Volgas DA. The posterolateral corner of the knee: Repair versus reconstruction. Am J Sports Med 2005;33:881-888. 15. Stannard JP, Black BS, Azbell C, Volgas DA. Posteromedial corner injury in knee dislocations. J Knee Surg 2012;25:429-434. 16. DeLong JM, Waterman BR. Surgical repair of medial collateral ligament and posteromedial corner injuries of
the knee: A systematic review. Arthroscopy 2015;31:22492255. e5. 17. Marx RG, Hetsroni I. Surgical technique: Medial collateral ligament reconstruction using Achilles allograft for combined knee ligament injury. Clin Orthop Relat Res 2012;470:798-805. 18. Liu X, Feng H, Zhang H, et al. Surgical treatment of subacute and chronic valgus instability in multiligamentinjured knees with superficial medial collateral ligament reconstruction using Achilles allografts: A quantitative analysis with a minimum 2-year follow-up. Am J Sports Med 2013;41:1044-1050.
Abstract: Injuries to the medial collateral ligament (MCL) and posteromedial corner can occur in isolation or in the setting of multiligamentous knee injuries. Reconstruction of the MCL and posteromedial corner is indicated in the setting of a multiligamentous knee injury. Isolated cases failing nonoperative treatment may also undergo surgical treatment. Our preferred technique for anatomic medial-sided knee reconstruction is an open anatomic MCL reconstruction using an Achilles tendon allograft along with direct repair of all associated medial and posteromedial structures.
T
he superficial medial collateral ligament (MCL) and its complementary medial structures, including the deep MCL, posterior oblique ligament (POL), and semimembranosus, are the key components providing valgus stability to the knee. Medial-sided injuries involving the superficial MCL constitute the most common ligamentous injury of the knee.1 The superficial MCL femoral origin is located 3.2 mm proximal and 4.8 mm posterior to the medial epicondyle. The ligament inserts distally on the tibia at 2 points, approximately 12.2 mm and 61.2 mm distal to the joint line (Fig 1).2 MCL injury severity is categorized as grade 1, grade 2, and grade 3 based on asymmetrical medial joint space opening to valgus stress of 2 to 5 mm, 6 to 10 mm, and greater than 10 mm, respectively.3 Excellent results after nonoperative treatment of all 3 grades of MCL injury have been reported.4,5 Nonoperative treatment results are inferior in the setting of multiligament injury, valgus knee alignment, and associated injury to the POL, deep MCL, and semimembranosus tendon.3,6,7 Healing
From the Department of Orthopedic Surgery and Sports Medicine, Mayo Clinic, Rochester, Minnesota, U.S.A. The authors report the following potential conflict of interest or source of funding: A.J.B. and M.J.S. receive support from Arthrex, Stryker, and USA Hockey Foundation. B.A.L. receives support from Clinical Orthopaedics and Related Research, Arthrex, National Institutes of Health, and VOT Solutions. Received May 7, 2015; accepted August 25, 2015. Address correspondence to Bruce A. Levy, M.D., Department of Orthopedic Surgery, Mayo Clinic, 200 First St SW, Rochester, MN 55905, U.S.A. E-mail: [email protected] Ó 2016 by the Arthroscopy Association of North America 2212-6287/15434/$36.00 http://dx.doi.org/10.1016/j.eats.2015.08.013
potential may also be impaired when a distal tibial MCL avulsion is associated with interposition of the pes tendons (the so-called Stener lesion of the knee).8 The decision to address the posteromedial corner (PMC) is determined by the anteromedial drawer test. Asymmetry of greater than 10 to 15 indicates disruption of the PMC. This test is similar to an external rotation drawer test except that with anteromedial rotatory instability, the tibia externally rotates and the medial tibial step-off increases as opposed to decreases as seen in posterolateral corner injuries. In addition, valgus instability of greater than 10 in full extension indicates disruption of the MCL, PMC, and cruciate ligaments (Fig 2). When surgical intervention is indicated, our preferred technique is an open anatomic MCL reconstruction using an Achilles tendon allograft along with direct repair of all associated medial and posteromedial structures (Table 1, Video 1).
Graft Selection A fresh-frozen, nonirradiated Achilles tendon allograft (Musculoskeletal Transplant Foundation, Edison, NJ) with a 9 20emm calcaneal bone block is prepared.
Patient Positioning The patient is initially positioned supine with the foot of the bed down using a standard leg holder to facilitate concomitant cruciate ligament reconstruction, if necessary. The foot of the table is then raised, and a foam ramp (Bone Foam, Plymouth, MN) and new sterile drape are placed under the operative leg for the subsequent medial-sided reconstruction. Alternatively, the foot of the table can be left raised, and the cruciate
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Fig 2. Fluoroscopic image of a right knee showing significant valgus stress. The medial joint space is significantly widened (arrow), consistent with a combined medial collateral ligament and posteromedial corner injury.
Fig 1. Drawing by LaPrade et al.2 showing the relevant anatomic landmarks of the posteromedial corner insertions on the femur and superficial and deep medial collateral ligament insertions on the tibia. It is important to appreciate the femoral insertion of the superficial medial collateral ligament (sMCL) just posterior and proximal to the medial epicondyle (ME), along with its 2 tibial insertions 12.2 mm and 61.2 mm distal to the joint line. One should also note the meniscofemoral and meniscotibial ligament insertions of the deep medial collateral ligament. The posterior oblique ligament (POL) is shown at its average distance of 7.7 mm distal and 6.4 mm posterior to the adductor tubercle (AT) and 1.4 mm distal and 2.9 mm anterior to the gastrocnemius tubercle (GT). Lastly, the medial patellofemoral ligament (MPFL) and adductor magnus tendon (AMT) are shown. Reprinted with permission.2 (MGT, medial gastrocnemius tendon.)
ligament reconstruction can be performed with the foot secured with an adjustable holder, alleviating the need to redrape.
Surgical Technique The surgical approach for a medial-sided reconstruction is planned according to concomitant pathology. A longitudinal, anteromedial incision with a full-thickness
medial skin flap is used when additional medial or posteromedial pathology is present, such as in the case of a medial meniscus tear requiring repair or PMC disruption. Two smaller incisions over the femoral and tibial MCL attachment sites can be used for an isolated MCL reconstruction. The distal tibial insertion is exposed first. A 4-cm incision is made approximately 1 cm medial to the tibial tubercle, allowing exposure distal and proximal to the superficial MCL insertion sites. The sartorius fascia is incised, and the pes tendons are retracted distally, exposing the MCL insertion, approximately 6 cm from the joint line.2 The distal insertion point should be recreated just anterior to the posterior border of the tibia, with the surgeon leaving just enough room so that
Table 1. Indications and Contraindications of MCL Reconstruction Indications Multiligament knee injury Injury to associated structures (i.e., POL, semimembranosus, and deep MCL) Chronic valgus instability Contraindications Isolated MCL injury with potential to heal with conservative management Acute repairable injury MCL, medial collateral ligament; POL, posterior oblique ligament.
MEDIAL COLLATERAL LIGAMENT RECONSTRUCTION
the 18-mm spiked washer (Arthrex, Naples, FL), used for fixation, does not overlap the posterior border (Fig 3). This area is exposed subperiosteally. Then, the femoral insertion is exposed by making a longitudinal incision over the medial epicondyle down to the crural fascia. Fluoroscopy helps to localize the origin of the superficial MCL, which averages 3.2 mm proximal and 4.8 mm posterior to the medial epicondyle.9,10 Once this landmark is identified, damage to the medial supporting structures, including the adductor magnus tendon, medial head of the gastrocnemius, POL, semimembranosus, and posteromedial capsule, is evaluated. All injured structures are repaired at this time, with the exception of the posteromedial capsule. This is accomplished by placing pre-loaded 2.8-mm metal SutureTak suture anchors (Arthrex) along the posterior aspect of the medial femoral condyle. A longitudinal split posterior to the MCL insertion creates a tissue flap posteriorly containing the posteromedial capsule and POL that may be imbricated after the MCL reconstruction is performed. Isometry of the MCL reconstruction is evaluated by inserting a 2.4-mm guide pin into both the femoral and tibial MCL insertion points and then placing a Mersilene tape (Ethicon, Cincinnati, OH) around the 2 pins. A blue marking pen is used to mark the tape at the 2 insertion sites where the pins enter the bone. The knee is flexed and extended to determine if adjustments are necessary at the femoral pin site to ensure isometric positioning (Fig 4). If the blue mark on the tape lengthens in flexion (i.e., tight in flexion), the femoral pin is repositioned posteriorly by a few millimeters at a time until isometry is achieved (Fig 5). Finding isometry can also be achieved using intraoperative fluoroscopy as described by Wijdicks et al.9 Once isometry is confirmed, a 9 25emm socket is created over the femoral pin, the socket is tapped with a 9-mm tap, and the calcaneal bone plug is fixed with a 7 25emm BioComposite interference screw (Arthrex) (Fig 6). Two suture anchors are placed 12 mm distal to the joint
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Fig 4. Testing isometry with 2.4-mm guide pins (arrows) placed at the femoral and distal tibial superficial medial collateral ligament attachment sites.
line to re-create the proximal tibial insertion. Fluoroscopy may also be useful for this step to ensure that the anchors are placed posterior enough to be in line with the distal insertion site. The graft is passed deep to the sartorial fascia. A small split is made in the graft for the screw at the distal insertion site. A No. 2 nonabsorbable suture is placed in whipstitch fashion up and down 3 cm from the split. At the distal tibial insertion site, a 3.2mm bicortical drill hole is created. The graft is secured to the tibia with a 4.5-mm bicortical screw (Arthrex) and 18-mm spiked washer (Arthrex) at 20 of knee flexion while a varus stress is applied (Fig 7). Secondary fixation is achieved by tying the graft sutures around the screw and washer. The proximal tibial insertion is re-created by tying the sutures from the previously placed 2.8-mm SutureTak suture anchors in a mattress fashion through the graft (Fig 8). Lastly, the posteromedial capsuleePOL complex is repaired or imbricated by placing 2 to 3 suture anchors at the posterior margin of the medial femoral condyle just distal and anterior to the gastrocnemius tubercle. Mattress sutures are placed into the capsular and POL tissue and then tied in full extension to effect the repair. If the sutures in the capsule are tied in flexion, full extension may not be achieved. The capsule is closed with No. 0 braided absorbable sutures. Accurate hardware placement is confirmed with fluoroscopy (Table 2).
Postoperative Course
Fig 3. Electrocautery (arrow) is used to mark the fixation point at the distal tibial superficial medial collateral ligament insertion site, just off the posterior border of the tibia, 6 to 7 cm distal from the medial joint line.
The specific rehabilitation protocol depends on concomitant procedures performed along with the MCL reconstruction. In general, a hinged brace with a slight varus mold is used for the first 6 weeks. The brace is locked in extension with toe-touch weight bearing during ambulation and unlocked for knee range-ofmotion exercises. After 6 weeks, progressive weight bearing is allowed with the brace unlocked. At 12 weeks, the patient can bear full weight while wearing a custom varus-molded knee brace.
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Fig 5. Wijdicks et al.9 described the radiographic landmarks defining the femoral insertion of the superficial medial collateral ligament (sMCL). Line 1 is an extension of the posterior femoral cortex, and line 2 is drawn perpendicular to line 1, intersecting the most posterior aspect of the Blumensaat line. The femoral attachment of the sMCL was found to be, on average, 8.6 mm anterior to the posterior femoral cortex line and 11.0 mm distal to the intersection of the posterior femoral cortex line (line 1) and the line intersecting the posterior aspect of the Blumensaat line (line 2). Reprinted with permission.9 (A, adductor tubercle; B, MPFL; C, gastrocnemius tubercle; D, POL; E, sMCL; F, medial epicondyle; MPFL, medial patellofemoral ligament; POL, posterior oblique ligament.)
Discussion Injuries to the MCL are common, but most can be treated successfully by nonoperative functional rehabilitation protocols. Accepted surgical techniques for treatment of MCL injuries include various reconstruction techniques, such as that described in this report, and direct ligament repair. A recent review of the literature by DeLong and Waterman11 described numerous variations in MCL reconstruction techniques, with a lack of high-quality literature comparing these techniques.
Currently, there is a paucity of literature comparing repair versus reconstruction of the MCL. Kovachevich et al.12 found satisfactory results for both repair and reconstruction. They emphasized the fact that the existing literature lacks the homogeneity of classification systems, clearly defined objective outcome scores, high levels of evidence, and direct comparison of treatment methods to make recommendations on the superiority of either technique.12 Higher failure rates have been shown with lateral-sided repairs versus reconstruction in the multiligament-injured knee.13,14
Fig 6. The 9 25emm femoral socket is reamed and tapped, and the calcaneal bone plug is fixed in place with a 7 25emm BioComposite interference screw. Arrow shows the tap for femoral socket.
Fig 7. The distal tibial superficial medial collateral ligament attachment is secured with a 4.5-mm bicortical screw and 18mm spiked washer at 20 of knee flexion while a varus stress is applied. Arrow points to the screw and washer.
MEDIAL COLLATERAL LIGAMENT RECONSTRUCTION
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Table 3. Advantages and Disadvantages of MCL Reconstruction Advantages Straightforward technique Bone-to-bone healing at femur Broad tendon coverage at tibia, similar to native MCL Disadvantages Need for allograft Possible hardware irritation MCL, medial collateral ligament.
Fig 8. Anteroposterior radiographic image of proximal tibial superficial medial collateral ligament attachment re-created with 2.8-mm metal SutureTak anchors. The arrows demonstrate proper placement of the proximal tibial SutureTak anchors.
Similar findings have been shown for medial-sided injuries in this setting. Stannard et al.15 reported on 73 knee dislocations that required MCL-PMC repair or reconstruction. In this nonrandomized, comparative, prospective study, the repair group had a failure rate of 20% whereas the reconstruction group had a failure rate of only 4%. This difference was highly significant. In a systematic review of MCL repair, DeLong and Waterman16 highlighted the fact that MCL repair remains a relevant treatment choice in cases of acute MCL injury but should be used with caution in cases of chronic MCL deficiency. When operative treatment is indicated, we prefer a medial-sided repair with an anatomic MCL reconstruction using Achilles tendon allograft. Two studies using an almost identical technique for MCL reconstruction with medium-term follow-up reported ligamentous stability and reliable subjective clinical outcomes.17,18 This technique is technically straightforward, easily reproducible, and clinically reliable. It has the advantage of bone-to-bone healing at the femur and broad tendon coverage at the tibia, similar to the native MCL insertion. The disadvantage of this technique is that it requires an allograft. In addition, Table 2. Technique Pearls and Pitfalls of MCL Reconstruction Pearls Use fluoroscopy to mark the femoral incision, which is often more posterior than expected. Be sure to identify the posterior border of the tibia for the distal superficial MCL insertion. Be sure the ends of the whipstitch exit the inferior aspect of the distal tendon. Pitfalls Not fully seating the bone plug in the femoral socket before placing the interference screw Not checking isometry before creating the femoral socket Not re-creating both the distal and proximal superficial MCL attachments MCL, medial collateral ligament.
although very rare because of the low-profile design of the screw and washer, there is the possibility of hardware irritation (Table 3).
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