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Combined Posterolateral Corner Reconstruction With Remnant Tensioning and Augmentation in Chronic Posterior Cruciate Ligament Injuries: Minimum 2-Year Follow-Up
Combined Posterolateral Corner Reconstruction With Remnant Tensioning and Augmentation in Chronic Posterior Cruciate Ligament Injuries: Minimum 2-Year Follow-Up Kee-Hyun Lee, M.D., Young-Bok Jung, M.D., Ho-Joong Jung, M.D., Eui-Chan Jang, M.D., Kwang-Sup Song, M.D., Jae-Yoon Kim, M.D. and Sang-Hak Lee, M.D.
Purpose: To evaluate functional results and knee stability after tensioning of remnant posterior cruciate ligament (PCL) with anterolateral (AL) bundle reconstruction and posterolateral corner (PLC) reconstruction in chronic PCL and PLC injuries. Methods: Between March 2001 and March 2007, 95 patients with chronic PCL injuries combined with PLC injuries underwent tensioning of the remnant PCL with AL bundle reconstruction and PLC reconstruction. Among these 95 patients, 70 who were satisfied with our inclusion were reviewed. The mean follow-up period was 40.1 months (range, 24 to 96 months). Tensioning of remnant PCL fibers was performed by distal transfer of the posterior tibial attachment. The AL bundle of the PCL was reconstructed by use of the modified inlay technique. The PLC reconstructive procedure was performed with a single sling through fibular tunnel. Stability was measured on posterior stress radiographs and by use of a maximal manual displacement test performed with a KT-1000 arthrometer (MEDmetric, San Diego, CA). The International Knee Documentation Committee and Orthopädishe Arbeitsgruppe Knie scoring systems were used for clinical evaluation. Results: Stress radiographs showed that the mean side-to-side difference (posterior tibial translation compared with that of the contralateral knee) was reduced from 10.3 ⫾ 2.4 mm preoperatively to 2.2 ⫾ 1.5 mm at the last follow-up (P ⬍ .001), whereas the KT-1000 tests showed that this difference was reduced from 8.4 ⫾ 2.2 mm preoperatively to 2.0 ⫾ 1.4 mm (P ⬍ .001). The final International Knee Documentation Committee objective score was A in 30 patients (42.8%), B in 34 (48.6%), and C in 6 (8.6%). The mean Orthopädishe Arbeitsgruppe Knie score improved from 63.5 ⫾ 10.4 to 88.9 ⫾ 7.6 (P ⬍ .001). Conclusions: Excellent posterior stability and relatively good clinical results were achieved with tensioning of the remnant PCL and AL bundle and PLC reconstruction by use of fibular tunnel for patients with chronic combined PCL-PLC injuries. Level of Evidence: Level IV, case series.
A
lthough arthroscopic instruments and surgical technique are advanced, the most effective arthroscopic posterior cruciate ligament (PCL) reconstruction method has not been well established. It is
From the Department of Orthopaedic Surgery, Medical Center of Chung-Ang University, Seoul, Republic of Korea. Supported by Chung-Ang University research grants in 2009. The authors report no conflict of interest. Received September 26, 2009; accepted November 4, 2010. Address correspondence to Young-Bok Jung, M.D., Department of Orthopaedic Surgery, Medical Center of Chung-Ang University, 224-1, Heukseok-dong, Dongjak-ku, Seoul, 156-755, Republic of Korea; E-mail: [email protected] Crown Copyright © 2011 Published by Elsevier Inc. on behalf of the Arthroscopy Association of North America. All rights reserved. 0749-8063/9576/$36.00 doi:10.1016/j.arthro.2010.11.007
generally known that the PCL has higher healing potential than the anterior cruciate ligament because of a rich blood supply (near the branch of the middle genicular artery) and coverage with a thicker synovium.1,2 Initially after an acute PCL injury, magnetic resonance imaging (MRI) shows a discontinuity of the PCL, but even without surgical intervention, the discontinuity improves.3,4 Recently, a remnant bundle preservation technique has been reported.5,6 The remaining structures of the PCL potentially benefit from enhancement of the revascularization, potentially preserving the proprioceptive function by use of the mechanoreceptors in the original PCL, in addition to adding to the mechanical stability of the knee joint.7,8 Starting in 1998, the senior author has used a modified inlay technique that tensions the anterolateral (AL) bundle of the remnant PCL. This procedure could
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apply for chronic cases at least 6 to 9 months after the initial PCL injury, in those that have lax but relatively good continuity and thickness in the original PCL fibers. The PCL is the primary restraint to posterior tibial translation and a secondary restraint to external tibial rotation.9,10 In addition, the posterolateral corner (PLC) has been shown to play a critical role in restraining external tibial rotation.11,12 It is well established that the PCL and the PLC work synergistically to limit both posterior tibial translation and external tibial rotation.9,12-14 Injury to the PLC structures of the knee can cause posterolateral rotatory instability (PLRI), a condition that has attracted increased attention over recent years. This injury is often associated with cruciate ligament injury, and its diagnosis can be difficult unless one has a high degree of clinical suspicion for an injury to the PLC structures.15,16 PLC injuries are now widely acknowledged as a major factor contributing to poor results in the overall treatment process, particularly if there is a concomitant cruciate ligament injury.10 In addition, it has been shown that failure to treat injuries to the PLC places the knee at risk for continued instability and the development of premature degenerative arthritis, even with a surgically reconstructed PCL.13,17 Although a number of treatment methods have been proposed over the past 20 years, there has been considerable controversy regarding the optimal method of surgical treatment for this injury.15,18-22 We thought that tensioning of the remaining fibers would improve the posterior stability of the knee joint. The purpose of this study was to evaluate the 2- to 8-year results of 70 chronic PCL and PLC reconstructions performed by a single surgeon with a minimum follow-up of 24 months (range, 24 to 96 months). We hypothesized that combined PCL reconstruction with additional reconstruction of the PLC structures would yield significantly improved knee function without serious complications. METHODS Patient Selection and Evaluation Between March 2001 and March 2007, the senior author performed arthroscopic PCL reconstruction surgery on 157 knees. The PCL injuries were graded according to the following scale: grade 1, partial tears of the PCL; grade 2, isolated, complete tear of the PCL; and grade 3, tear of the PCL with other associated ligament injury. Grade 3 PCL injuries were indi-
cated for surgical treatment when the patients had persistent pain or functional disability (discomfort on going down stairs). Chronic (⬎6 months) combined PCL-PLC injury cases that underwent PCL reconstruction by use of tensioning of the remnant PCL with AL bundle reconstruction by the modified inlay technique and posterolateral corner sling (PLCS) (PLC reconstruction by the fibular head tunnel) were included in this study cohort. Thirty patients who had undergone PCL reconstruction with acute or subacute injuries (⬍6 months) and thirty-two patients who had undergone double-bundle PCL reconstruction were excluded. Of the remaining 95 patients, 16 were excluded because they met 1 of the following exclusion criteria: (1) combined anterior cruciate ligament (ACL) reconstruction, (2) an associated fracture in the lower extremities of such magnitude that knee function could be affected, (3) combined severe life-threatening medical disease, and (4) revision surgery. Nine patients were lost to followup, which left 70 patients who met the inclusion criteria and could be followed up for a minimum of 24 months. The study was approved by the institutional review board of our hospital, and all patients provided informed consent. There were 62 male and 8 female patients aged 31.2 years on average (range, 16 to 59 years). The mean duration of the follow-up after surgery was 40.1 months (range, 24 to 96 months). The mean duration from the time of injury to PCL reconstruction was 23.7 months (range, 6 to 240 months). At the time of surgery, all PCL injuries were confirmed grade 3 lesions. Twelve patients were found to have a medial collateral ligament injury at evaluation. Abnormal articular cartilage surfaces were identified during the operation in 12 patients. The areas of cartilage damage were the patellofemoral compartment in 2 patients and the medial tibiofemoral compartment in 10 patients. Medial meniscal injuries were found in 8 patients, with lateral meniscal injuries in 2 patients. All patients had combined PLRI with grade 2 PLC injury. Only those cases with grade 2 PLC injury were enrolled in our series because PLC reconstruction was not indicated for grade 1 PLC injuries, and we used anatomic PLC reconstruction using the fibular head and the tibial tunnel simultaneously for cases with grade 3 PLC injury. We classified the PLC injuries according to varus and rotator instability, as assessed by the varus stress test, dial test, and posterolateral drawer test.23 For varus instability, the difference in the lateral joint space distance and the presence or absence of a firm end point were assessed and classi-
PCL RECONSTRUCTION AND PLCS IN CHRONIC INJURY fied as follows: grade 1, when the difference was less than 5 mm; grade 2, 5 to 10 mm with a firm end point; and grade 3, greater than 10 mm without a firm end point. To assess the degree of PLRI, we conducted the posterolateral drawer test at 30° and 90° of knee flexion as follows: with the thigh held by an assistant to prevent external rotation, the thumb of the examiner was placed in front of the lateral tibial plateau and the remaining fingers were placed in the popliteal space while external rotation force was applied to the ipsilateral foot by the contralateral hand. The thigh-foot angle and patella-tubercle angle were measured with a goniometer. Because of the difficulty of measuring small angles, the minimum measurement unit was set to 5°. The degree of rotation was compared with that of the contralateral side and was easily accessed by observing the position of the tibial tuberosity. The posterior subluxation of the lateral tibial plateau was considered to be more meaningful than the degree of rotation. The classification of PLC injuries was as follows: grade 1, increased external rotation by 5° to 10° compared with the contralateral side, without any varus instability; grade 2, increased external rotation by 10° or greater or posterolateral subluxation of the tibial plateau combined with grade 0 to 2 varus instability; and grade 3, increased external rotation by 10° or greater without a firm end point, combined with grade 3 varus instability from lateral collateral ligament injury (Table 1). There was 1 patient with genu recurvatum and a corrective osteotomy was performed first. Four bundles of autogenous hamstring were used as a graft in AL bundle reconstruction of the PCL in 66 patients, an Achilles allograft tendon in 3 patients, and a tibialis anterior allograft tendon in 1 patient. Autogenous hamstring tendon was used for tendon graft for PLC reconstruction in 65 patients, tibialis anterior allograft in 3 patients, and tibialis posterior allograft in 2 patients. Surgical Technique All patients underwent tensioning of the remnant PCL with AL bundle reconstruction and PLCS (PLC
TABLE 1. Grade 1 Grade 2 Grade 3
Grade of PLC Injury
ER* ⬍10° without varus instability ER ⱖ10° or posterolateral tibial subluxation ⫹ grade 0-2 varus instability ER ⱖ10° or posterolateral tibial subluxation ⫹ grade 3 varus instability
*Degree of external rotation compared with contralateral side.
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reconstruction by the fibular head tunnel) performed by the senior author. Our surgical technique has been described elsewhere,6,24,25 and we describe here specific technical aspects of arthroscopically assisted PCL-PLC reconstruction. The femoral tunnel is made by an outside-in technique without removal of the remnant PCL. The desired femoral tunnel is placed 5 to 6 mm proximal to the margin of the articular cartilage of the medial femoral condyle at approximately the 12:30- to 1-o’clock position on the right knee and at the 11- to 11:30-o’clock position on the left. A femoral tunnel is made without damage to the remnant PCL bundle, and a 21-gauge wire loop is passed through the femoral tunnel, directed just toward the medial side of the remnant PCL of the tibia, and later used to pass the graft from the PCL tibial insertion area into the femoral tunnel. For the posterior approach to the knee, the operating table is tilted over 30° and the knee is flexed 70° to 90° to provide easier access to the popliteal area. After a posteromedial approach, a tibial attachment of the PCL is demarcated as a 1.5 ⫻ 2– cm area by use of an osteotome, and a 7-mm-thick bone block is detached from the distal to proximal area by use of a 1.2- to 1.5-cm-wide curved osteotome. A bony trough is made at the medial side of the PCL tibial insertion just distal to the portion of the bone-block– detached site, to which the detached bone block and graft are to be fixed. Autogenous hamstring 4-bundle graft is passed through the knee joint into the femoral tunnel and fixed on the cortical bone of the distal and medial side of the tibial insertion of the PCL with a 10-mm staple or post-tie. Then, the remnant PCL is tensioned by pulling the bone block distally by use of a stitch of No. 5 nonabsorbable Ethibond suture (Ethicon, Somerville, NJ). The step-off as anatomic reduction is confirmed and the remnant PCL bone block is fixed on the bone block to the tibia by use of a 5- or 6.5-mm cannulated screw with a spiked washer. The operating table is changed back to the neutral position, and the graft is cyclically loaded in tension with 15 to 20 lb and is fixed with a biodegradable interference screw at the femoral tunnel with the knee joint in 70° to 90° of flexion and also fixed with a 10-mm staple or post-tie on the femoral side. Finally, the knee joint is assessed once more to determine whether full extension and flexion are possible without any resistance. PLC reconstruction was performed by our modification of the fibular tunnel method originally described by Larson.26 Two separate 2- to 3-cm incisions were made transversely over the lateral epicondyle
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and obliquely over the fibular head. The fibular tunnel was prepared to a 5- to 6-mm tunnel depending on the graft size obliquely from the anteroinferior to posterosuperior aspect on the fibula with the aid of the ACL guide. Protecting with a curette helped prevent injury to the peroneal nerve, when the fibula head is reamed. The isometric point was examined after insertion of a guide pin at a point 5 to 7 mm anterior and distal to the lateral epicondyle of the femur. After confirmation that the isometric point was less than 3 mm in maximum flexion and extension, the femoral tunnel, with the same diameter of the 4 stranded grafts, was enlarged and chamfered with a rasp. The hamstring tendon autograft was passed through the fibula head tunnel, under an iliotibial band in a figure-of-8 pattern. The grafts were fixed with a bioabsorbable interference screw, at the femoral tunnel, during an 8- to 10-lb tension state in neutral rotation and 70° of flexion of the knee after 20 times cyclic loading while the foot was supported, to negate the effect of traction on the graft by the weight of the leg (Fig 1). Rehabilitation Postoperative rehabilitation varied in each patient according to the rigidity of graft fixation, the degree of isometry, and the results of the final intraoperative stress test after reconstruction. Because the PLC reconstructions were performed at the same time as the PCL reconstructions, passive range-of-motion exercises usually were started on the third to fifth postoperative day. Passive range of motion was attempted while the surgeon or patient held the proximal tibia to avoid posterior displacement by gravity. In addition, passive-assisted exercises were performed in the prone position. The range of motion was increased from 0° to 90° during the first 6 weeks.
The knee was immobilized with a long leg removable splint for 2 to 3 weeks after surgery, followed by a PCL brace until the sixth postoperative week. The goal was to regain full range of motion before the 12th to 24th postoperative week. The patients maintained partial weight bearing for 6 weeks and progressed to full weight bearing in extension, as pain permitted. Stationary bicycling was allowed from the seventh week onward. Strengthening of the hamstring muscles was not allowed until the fourth month after surgery, because the action of the hamstrings could potentially have a negative effect on the PCL and PLC structures. Progressive rehabilitation exercises were performed thereafter, which included not only muscle strengthening but also an adaptation strategy for anticipated activities. Patient Assessment Serial postoperative evaluations were performed at 6 weeks; at 3, 6, and 12 months; and every 12 months thereafter. To evaluate the stability of the knee, a posterior stress radiograph (push view), obtained with a Telos stress device (Telos, Marburg, Germany), and a maximum manual displacement test with the KT1000 arthrometer (instrumented drawer testing; MEDmetric, San Diego, CA) were used preoperatively and at every follow-up after the third postoperative month. The posterior stress radiograph was obtained with a force of 150 N with the knee flexed to 90°. The difference between the involved and contralateral limbs was recorded. The maximum manual displacement test with the KT-1000 arthrometer was performed with the knee flexed to 70°, by pushing the tibia posteriorly before performing a maximum manual anterior drawer test. To evaluate the functional results, the knee scoring systems of the Orthopädishe Arbeitsgruppe
FIGURE 1. Schematic diagrams of PLC reconstruction using fibular head tunnel.
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Knie (OAK) and the International Knee Documentation Committee (IKDC) were used. All evaluations were made by 1 observer who had not been involved in the operation. For assessment of PLRI, the posterolateral drawer test, dial test, and varus stress test were performed at every follow-up, and the results compared with the results of evaluation of the contralateral side. Statistical Analysis Statistical analysis of the clinical results in the mean scores according to the OAK system between the preoperative and the last follow-up evaluations was performed by use of paired t test. The Wilcoxon signed rank test was used to determine the significance of differences between the preoperative evaluations and evaluations at last follow-up, mean side-to-side differences as shown on posterior stress radiographs, and maximum manual displacement test results. All statistical analyses were carried out with SAS software, version 9.13 (SAS, Cary, NC). P ⬍ .05 was considered significant. RESULTS Stability The mean side-to-side difference in posterior translation, as measured by posterior stress radiography, was 10.3 ⫾ 2.4 mm preoperatively and 2.2 ⫾ 1.5 mm at the last follow-up. At the last evaluation, 40 patients (57.1%) exhibited displacement of less than 3 mm, 26 (37.1%) had between 3 and 5 mm of displacement, and 4 (5.7%) showed displacement exceeding 5 mm (Fig 2). The difference between the last follow-up evaluation value and the value before the reconstruction was significant (P ⬍ .001). The mean side-to-side difference as measured by the maximal manual test with the KT-1000 arthrometer was 8.4 ⫾ 2.2 mm preoperatively and 2.0 ⫾ 1.4 mm at the last follow-up evaluation. At the last evaluation, 44 patients (62.9%) exhibited less than 3 mm of displacement, 25 (35.7%) had between 3 and 5 mm of displacement, and 1 (1.4%) had more than 5 mm of displacement. The difference between the value after the last follow-up relative to the value before the reconstruction was significant (P ⬍ .001) (Table 2). At the last evaluation, rotational stability was assessed according to different knee flexion values (30° and 90° of flexion): 14 patients (20%) were overconstrained, 50 (71.4%) were constrained, and 6 (8.6%) were lax, as compared with the normal side. Thus
FIGURE 2. (A) Radiographs of 20-year-old man in whom PCL injury occurred while playing soccer. The stress test using the Telos device shows that there is a 13-mm side-to-side difference posteriorly on the radiograph. (B) Posterior stress radiographs at 5 years’ follow-up after the tensioning of the remnant PCL with reconstruction of the AL bundle and PLC reconstruction showed a 3-mm side-to-side difference posteriorly. In terms of function, the patient continues to engage in sports activity.
91.4% of the patients had achieved restoration of external rotational stability. In terms of varus instability, 2 patients (2.9%) were grade 1 and 68 (97.1%) were grade 0, as compared with the normal side. Clinical Results When the IKDC evaluation form was used, 30 patients (42.8%) were rated as A (normal), 34 (48.6%) as B (nearly normal), and 6 (8.6%) as C (abnormal). Hence, 91.4% of the patients had a rating of A or B at the last evaluation. The mean value of the IKDC
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K-H. LEE ET AL. Outcome Analysis in Terms of Stability Preoperative (N ⫽ 70)
Last Follow-up (N ⫽ 70)
10.3 ⫾ 2.4 0 0 43 (61.4%) 27 (38.6%) 8.4 ⫾ 2.2 0 2 (2.9%) 55 (78.6%) 13 (18.6%)
2.2 ⫾ 1.5 40 (57.1%) 26 (37.1%) 4 (5.7%) 0 2.0 ⫾ 1.4 44 (62.9%) 25 (35.7%) 1 (1.4%) 0
Stress view* ⬍3 mm 3-5 mm 6-10 mm ⬎10 mm KT-1000† ⬍3 mm 3-5 mm 6-10 mm ⬎10 mm
jective IKDC form, and OAK score of 92 points) at the time of the latest follow-up.
P Value
DISCUSSION
⬍.001
⬍.001
NOTE. The score is given as No. of cases (%) or mean ⫾ SD. *Posterior stress radiographs using Telos stress device (G. Scheuba, M.D.). †Manual maximum displacement test with knee flexed at 70° by use of KT-1000 arthrometer (instrumented drawer testing).
subjective score was 79.7 ⫾ 13.3 (range, 64 to 99). The mean OAK score was 63.5 ⫾ 10.4 (range, 42 to 86) preoperatively and 88.9 ⫾ 7.6 (range, 67 to 100) postoperatively. At the last evaluation, 31 patients (44.3%) were classified as excellent, 30 (42.8%) as good, 7 (10%) as fair, and 2 (2.9%) as poor. Thus 87.1% of the patients had a good or excellent rating at the last evaluation. The difference between OAK scores before reconstruction and at last follow-up evaluation was significant (P ⬍ .001) (Table 3). Complications There was 1 patient with intraoperative complications during PLCS from injury to the peroneal nerve, which sustained direct damage by the reamer or guide pin. Our patients had complete recovery at final follow-up. During the early period of this study, 1 patient sustained an incomplete fracture of the fibular neck when we constructed the fibular tunnel. The fracture was not addressed because there was acceptable stability of the graft after reconstruction, and the patient had grade 1 PLRI at final follow-up. We thought that the fracture of the fibular neck resulted from a transverse tunnel; thus we made an oblique tunnel, and thereafter the fracture has not recurred. In another patient, PLRI and varus instability recurred 2 years after the operation. On physical examination, grade 3 PLRI was found to present. Thus anatomic PLC reconstruction by grafting through the fibular head and the tibial tunnel simultaneously was performed. The patient had a good clinical outcome score (grade A on objective IKDC form, 82 points on sub-
The principal findings of this study showed that combined PCL-PLC instabilities can be successfully treated with simultaneous reconstruction of PCL and PLC structures. It included only chronic cases treated by the same PCL-PLC reconstruction technique with relatively larger numbers by a single surgeon. Most patients recover a functionally stable knee with considerably improved knee function as noted by both subjective criteria and objective measurement methods. Recently, there has been an increased understanding of the biomechanics and function of the PCL and PLC, an improvement in the investigation of these injuries. New techniques of reconstruction have been developed, but reports of the results remain limited.18,27-29 There are several clinical series reporting results of PLC reconstruction combined with PCL reconstruction. In 1996 Noyes and Barber-Westin17 reported 3 fully functional cases, 1 partially functional case, and 5 cases of failure in 9 knees undergoing combined PCL reconstruction and proximal advancement of the lateral collateral ligament and the PLC, with follow-up of 23 to 90 months. In 2002 Wang et al.30 reported on 25 patients who all had transtibial single-bundle PCL reconstruction and PLC reconstruction by the technique of Larson26 plus some additional lateral collateral ligament advancement, with overall satisfactory results in 68% of patients and restoration of ligament stability in 44%. In 2003 in the series of Kim et al.31 of 25 patients with PLRI
TABLE 3.
OAK Excellent Good Fair Poor IKDC subjective IKDC objective A B C D
Outcome Analysis of Clinical Score Preoperative (N ⫽ 70)
Last Follow-up (N ⫽ 70)
63.5 ⫾ 10.4 0 1 (1.4%) 17 (24.3%) 52 (74.3%) 50.6 ⫾ 16.8
88.9 ⫾ 7.6 31 (44.3%) 30 (42.8%) 7 (10%) 2 (2.9%) 79.7 ⫾ 13.3
0 0 42 (60%) 28 (40%)
30 (42.8%) 34 (48.6%) 6 (8.6%) 0
P Value ⬍.001
⬍.001 ⬍.001
NOTE. The score is given as No. of cases (%) or mean ⫾ SD.
PCL RECONSTRUCTION AND PLCS IN CHRONIC INJURY combined with PCL injuries, all had transtibial singlebundle PCL reconstruction and PLC reconstruction by use of biceps tenodesis, with satisfactory results based on IKDC scores in 76%, and restoration of external rotational stability in 64%. In 2004 Fanelli and Edson18 reported a series of 41 patients who all had transtibial single-bundle PCL reconstruction with Achilles allograft, biceps tenodesis, and posterolateral capsular shift, with satisfactory posterior stability in 70% and restoration of external rotational stability in 98%. In our series of 70 patients, all underwent PCL reconstruction combined with PLC reconstruction with the fibular tunnel technique, with satisfactory results in 91% by IKDC scores and in 87% by OAK scores, as well as restoration of external rotational stability in 91%. Our results, especially in terms of the stability, were much improved compared with the previously mentioned series. This may be because of several reasons. First, tensioning of the remnant PCL probably produced better stability. Most PCL injuries occur with the knee in flexion; when they happen, the AL bundle of the PCL is tensed and severed whereas the posteromedial bundle and meniscofemoral ligament remain intact.32,33 In addition, it is known that the PCL has better synovial coverage, blood circulation, and spontaneous healing potential than does the ACL. Many MRI studies3,4,34 and an experimental animal study35 have shown that an acute ruptured PCL has healing potential. Therefore the PCL seems to have spontaneous healing potential even in the case of rupture at the substance, although it leaves laxity. Safran et al.7 reported that the mechanoreceptors in PCL-injured knees act as knee stabilizers, which explains why degenerative changes develop more slowly in patients with posterior instability than in those with anterior instability. Therefore, if the remnant of the PCL is not resected but is tensioned surgically, there would be an advantage of preserving the proprioceptive function of the mechanoreceptor in a continuous PCL and stability as similar as possible to the normal PCL. On the basis of this fact, we hypothesized that the tensioning of the remnant PCL fibers and augmentation of the AL bundle would contribute to posterior knee stability. We recommend this technique for chronic cases at least 6 months after the initial PCL injury, in those that have a good density and 50% to 60% thickness in the remnant PCL bundles as shown by MRI. If the remnant PCL is very weak and narrow, we recommend a double-bundle PCL reconstruction. The second possible reason is that the tibial inlay technique produced better stability than the transtibial technique. Many surgeons have suggested that, in a
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reconstruction of the PCL, the excessive angular deformity of the graft at the posterior opening of the tibial tunnel—the so-called killer turn or killer curve36-38—may result in failure and stretching of the graft. Berg36 described popliteal fossa exposure with tibial inlay reconstruction as a solution to this problem. This procedure allows secure direct fixation to the posterior proximal tibia. In a biomechanical comparison of the transtibial and tibial inlay technique, Bergfeld et al.37 and Markolf et al.38 described more severe wearing and loosening of the graft with transtibial PCL reconstruction after cyclic loading, supporting the efficacy of tibial inlay reconstruction in achieving posterior stability of the knee. Until recently, many authors have described numerous tibial inlay techniques, as well as their advantages and good clinical outcomes.27,39 However, the disadvantage of the tibial inlay technique is that access to the anterior and posterior knee with a position change is necessary during the surgical procedure. We also found that exposing the popliteal fossa is difficult with the patient in the lateral decubitus position. Therefore, we choose to use a modified inlay technique that facilitates the posteromedial approach by table tilting at 30° down on the affected side.25,40 The third important factor includes diagnosis and treatment of the posterolateral rotator instability. PCL injuries are associated commonly with PLC injuries.41-43 Biomechanical studies have shown that cutting the posterolateral structures increases the in situ forces on the PCL.13,44 Recurrent laxity after PCL reconstruction is most commonly related to untreated PLC injuries.32,43,45 Thus great efforts have been made to find the appropriate diagnosis and treatment for PLC injuries. However, a uniformly accepted approach has yet to be established. We used both the posterolateral drawer test and dial test for diagnosis of PLRI. In posterolateral drawer test, the posterior subluxation of the lateral tibial plateau was checked as well as the degree of the tibial external rotation. To assess the degree of rotation accurately, the posterolateral drawer test and dial test was performed with reduction of a posteriorly subluxated tibia. If the knee is examined in a state of altered anatomic positioning, a PLC injury may potentially be missed. In a combined PCL-PLC–injured knee, a reduced force applied to the tibia increased the overall amount of observed tibial external rotation during the dial test.46,47 This means that many patients may not be treated if they are borderline grade 1 or 2 in the subluxated position of the knee. More recent studies have shown that the popliteofibular ligament plays a key role in resistance to pos-
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terior translation, varus stress, and external rotation, and this ligament’s reconstruction should be incorporated into any surgical technique used to correct PLRI of the knee.48-51 The fibular tunnel sling technique described in this series approximates the anatomy of the static portion of the popliteofibular ligament and the fibular collateral ligament (FCL). In our procedure the posterior portion was designed to re-create the popliteofibular ligament and the anterior portion was designed to re-create the FCL. The fibular tunnel has advantages in that it can be easily visualized, and the skin incision is shorter. In addition, biomechanically, the FCL reconstructed by the fibular head tunnel method more closely approximates the anatomy of the natural FCL, and it is thought that a sling pulled outward anterior to the fibular head may be biomechanically superior. Theoretically, a popliteofibular graft should be more effective in controlling external rotation than a popliteus graft because it is fixed at a greater distance from the axis of tibial rotation, thus giving it a greater mechanical advantage. LaPrade et al.20 and Chang et al.48 have reported that “anatomic” PLC reconstruction is necessary to improve the clinical results of PLC reconstruction; however, Apsingi et al.52 have reported that the anatomic reconstruction did not perform better than the 2-strand technique. We have had some experience with a popliteal bypass procedure: the localization of the tibial tunnel is somewhat inaccurate, and thus it requires the help of image amplifiers. Furthermore, because the posterior tibial tunnel orifice is placed too deep, graft passage may be sufficiently difficult so that the surgical time is increased.24 Thus we recommend that the PLC reconstruction by use of fibular tunnel is simpler, is biomechanically superior, and causes less surgical morbidity than a tibial tunnel method when PLRI concomitant to PCL injury was less than 2°. However, for cases with 3° of PLC injury, one should consider repairing the injuries anatomically by grafting through the fibular head and the tibial tunnel simultaneously. Our study suffers from some limitations, including (1) a relatively short-term follow-up period, (2) the absence of a control group with a different surgical technique for PCL-PLC injuries, and (3) the lack of evaluation of proprioception. In addition, this study was retrospective and not a randomized controlled trial. Therefore the reason for the improvement in the stability and clinical results cannot be defined precisely. On the other hand, our study comprises a relatively large series of chronic PCL and PLC injuries objectively evaluated by use of multiple knee scores as well as stress radiography and
KT-1000 arthrometer, performed by a single surgeon. Moreover, considering the aforementioned potential benefit, tensioning of the remnant fiber and simultaneous PLC reconstruction might be worthwhile in chronic PCL-PLC injuries.
CONCLUSIONS Tensioning of the remnant PCL with AL reconstruction and PLC reconstruction by use of the fibular tunnel in chronic PCL and PLC injuries greatly restored posterior stability and improved the function of the knee. REFERENCES 1. Bray RC, Leonard CA, Salo PT. Vascular physiology and long-term healing of partial ligament tears. J Orthop Res 2002;20:984-989. 2. Scapinelli R. Vascular anatomy of the human cruciate ligaments and surrounding structures. Clin Anat 1997;10:151-162. 3. Shelbourne KD, Jennings RW, Vahey TN. Magnetic resonance imaging of posterior cruciate ligament injuries: Assessment of healing. Am J Knee Surg 1999;12:209-213. 4. Tewes DP, Fritts HM, Fields RD, Quick DC, Buss DD. Chronically injured posterior cruciate ligament: Magnetic resonance imaging. Clin Orthop Relat Res 1997:224-232. 5. Ahn JH, Yang HS, Jeong WK, Koh KH. Arthroscopic transtibial posterior cruciate ligament reconstruction with preservation of posterior cruciate ligament fibers: Clinical results of minimum 2-year follow-up. Am J Sports Med 2006;34:194-204. 6. Jung YB, Jung HJ, Tae SK, Lee YS, Yang DL. Tensioning of remnant posterior cruciate ligament and reconstruction of anterolateral bundle in chronic posterior cruciate ligament injury. Arthroscopy 2006;22:329-338. 7. Safran MR, Allen AA, Lephart SM, Borsa PA, Fu FH, Harner CD. Proprioception in the posterior cruciate ligament deficient knee. Knee Surg Sports Traumatol Arthrosc 1999;7:310-317. 8. Jung YB, Jung HJ, Yang JJ, et al. Characterization of spontaneous healing of chronic posterior cruciate ligament injury: Analysis of instability and magnetic resonance imaging. J Magn Reson Imaging 2008;27:1336-1340. 9. Grood ES, Stowers SF, Noyes FR. Limits of movement in the human knee. Effect of sectioning the posterior cruciate ligament and posterolateral structures. J Bone Joint Surg Am 1988;70:88-97. 10. Veltri DM, Deng XH, Torzilli PA, Warren RF, Maynard MJ. The role of the cruciate and posterolateral ligaments in stability of the knee. A biomechanical study. Am J Sports Med 1995;23:436-443. 11. Kurtz CA, Sekiya JK. Treatment of acute and chronic anterior cruciate ligament-posterior cruciate ligament-lateral side knee injuries. J Knee Surg 2005;18:228-239. 12. Sekiya JK, Haemmerle MJ, Stabile KJ, Vogrin TM, Harner CD. Biomechanical analysis of a combined double-bundle posterior cruciate ligament and posterolateral corner reconstruction. Am J Sports Med 2005;33:360-369. 13. Harner CD, Vogrin TM, Hoher J, Ma CB, Woo SL. Biomechanical analysis of a posterior cruciate ligament reconstruction. Deficiency of the posterolateral structures as a cause of graft failure. Am J Sports Med 2000;28:32-39. 14. Veltri DM, Deng XH, Torzilli PA, Maynard MJ, Warren RF. The role of the popliteofibular ligament in stability of the
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human knee. A biomechanical study. Am J Sports Med 1996;24:19-27. Albright JP, Brown AW. Management of chronic posterolateral rotatory instability of the knee: Surgical technique for the posterolateral corner sling procedure. Instr Course Lect 1998; 47:369-378. LaPrade RF, Terry GC. Injuries to the posterolateral aspect of the knee. Association of anatomic injury patterns with clinical instability. Am J Sports Med 1997;25:433-438. Noyes FR, Barber-Westin SD. Surgical restoration to treat chronic deficiency of the posterolateral complex and cruciate ligaments of the knee joint. Am J Sports Med 1996;24:415-426. Fanelli GC, Edson CJ. Combined posterior cruciate ligamentposterolateral reconstructions with Achilles tendon allograft and biceps femoris tendon tenodesis: 2- to 10-year follow-up. Arthroscopy 2004;20:339-345. Hughston JC, Jacobson KE. Chronic posterolateral rotatory instability of the knee. J Bone Joint Surg Am 1985;67:351-359. LaPrade RF, Johansen S, Wentorf FA, Engebretsen L, Esterberg JL, Tso A. An analysis of an anatomical posterolateral knee reconstruction: An in vitro biomechanical study and development of a surgical technique. Am J Sports Med 2004; 32:1405-1414. Lee MC, Park YK, Lee SH, Jo H, Seong SC. Posterolateral reconstruction using split Achilles tendon allograft. Arthroscopy 2003;19:1043-1049. Noyes FR, Barber-Westin SD. Surgical reconstruction of severe chronic posterolateral complex injuries of the knee using allograft tissues. Am J Sports Med 1995;23:2-12. Hughston JC, Norwood LA Jr. The posterolateral drawer test and external rotational recurvatum test for posterolateral rotatory instability of the knee. Clin Orthop Relat Res 1980:82-87. Jung YB, Jung HJ, Kim SJ, et al. Posterolateral corner reconstruction for posterolateral rotatory instability combined with posterior cruciate ligament injuries: Comparison between fibular tunnel and tibial tunnel techniques. Knee Surg Sports Traumatol Arthrosc 2008;16:239-248. Jung YB, Jung HJ, Tae SK, Lee YS, Lee KH. Reconstruction of the posterior cruciate ligament with a mid-third patellar tendon graft with use of a modified tibial inlay method. J Bone Joint Surg Am 2005;87:247-263 (Suppl 1). Larson RV. Isometry of the lateral collateral and popliteofibular ligaments and techniques for reconstruction using a free semitendinosus tendon graft. Oper Tech Sports Med 2001;9: 84-90. Cooper DE, Stewart D. Posterior cruciate ligament reconstruction using single-bundle patella tendon graft with tibial inlay fixation: 2- To 10-year follow-up. Am J Sports Med 2004;32: 346-360. Khanduja V, Somayaji HS, Harnett P, Utukuri M, Dowd GS. Combined reconstruction of chronic posterior cruciate ligament and posterolateral corner deficiency. A two- to nine-year follow-up study. J Bone Joint Surg Br 2006;88:1169-1172. Mariani PP, Becker R, Rihn J, Margheritini F. Surgical treatment of posterior cruciate ligament and posterolateral corner injuries. An anatomical, biomechanical and clinical review. Knee 2003;10:311-324. Wang CJ, Chen HS, Huang TW, Yuan LJ. Outcome of surgical reconstruction for posterior cruciate and posterolateral instabilities of the knee. Injury 2002;33:815-821. Kim SJ, Shin SJ, Jeong JH. Posterolateral rotatory instability treated by a modified biceps rerouting technique: Technical considerations and results in cases with and without posterior cruciate ligament insufficiency. Arthroscopy 2003;19:493-499. Harner CD, Hoher J. Evaluation and treatment of posterior cruciate ligament injuries. Am J Sports Med 1998;26:471-482. Race A, Amis AA. The mechanical properties of the two bundles of the human posterior cruciate ligament. J Biomech 1994;27:13-24.
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34. Akisue T, Kurosaka M, Yoshiya S, Kuroda R, Mizuno K. Evaluation of healing of the injured posterior cruciate ligament: Analysis of instability and magnetic resonance imaging. Arthroscopy 2001;17:264-269. 35. Jung YB, Lee TJ, Yang DL, Kim KS, Ko KW, Chung JW. Healing potential of the transected posterior cruciate ligament of the rabbit. J Korean Orthop Assoc 2001;36:25-32. 36. Berg EE. Posterior cruciate ligament tibial inlay reconstruction. Arthroscopy 1995;11:69-76. 37. Bergfeld JA, McAllister DR, Parker RD, Valdevit AD, Kambic HE. A biomechanical comparison of posterior cruciate ligament reconstruction techniques. Am J Sports Med 2001; 29:129-136. 38. Markolf KL, Zemanovic JR, McAllister DR. Cyclic loading of posterior cruciate ligament replacements fixed with tibial tunnel and tibial inlay methods. J Bone Joint Surg Am 2002;84: 518-524. 39. Chuang TY, Chen CH, Chou SW, Chen YJ, Chen WJ. Tibial inlay technique with quadriceps tendon-bone autograft for posterior cruciate ligament reconstruction. Arthroscopy 2004; 20:331-335. 40. Jung YB, Tae SK, Jung HJ, Lee KH. Replacement of the torn posterior cruciate ligament with a mid-third patellar tendon graft with use of a modified tibial inlay method. J Bone Joint Surg Am 2004;86:1878-1883. 41. Clancy WG Jr, Sutherland TB. Combined posterior cruciate ligament injuries. Clin Sports Med 1994;13:629-647. 42. Fanelli GC, Edson CJ. Posterior cruciate ligament injuries in trauma patients: Part II. Arthroscopy 1995;11:526-529. 43. Noyes FR, Barber-Westin SD. Posterior cruciate ligament revision reconstruction, part 1: Causes of surgical failure in 52 consecutive operations. Am J Sports Med 2005;33:646-654. 44. Markolf KL, Wascher DC, Finerman GA. Direct in vitro measurement of forces in the cruciate ligaments. Part II: The effect of section of the posterolateral structures. J Bone Joint Surg Am 1993;75:387-394. 45. Apsingi S, Nguyen T, Bull AM, Unwin A, Deehan DJ, Amis AA. Control of laxity in knees with combined posterior cruciate ligament and posterolateral corner deficiency: Comparison of single-bundle versus double-bundle posterior cruciate ligament reconstruction combined with modified Larson posterolateral corner reconstruction. Am J Sports Med 2008;36: 487-494. 46. Jung YB, Lee YS, Jung HJ, Nam CH. Evaluation of posterolateral rotatory knee instability using the dial test according to tibial positioning. Arthroscopy 2009;25:257-261. 47. Strauss EJ, Ishak C, Inzerillo C, et al. Effect of tibial positioning on the diagnosis of posterolateral rotatory instability in the posterior cruciate ligament-deficient knee. Br J Sports Med 2007;41:481-485; discussion 485. 48. Chang CB, Seong SC, Lee S, Yoo JH, Park YK, Lee MC. Novel methods for diagnosis and treatment of posterolateral rotatory instability of the knee. J Bone Joint Surg Am 2007; 89:2-14 (Suppl 3). 49. Maynard MJ, Deng X, Wickiewicz TL, Warren RF. The popliteofibular ligament. Rediscovery of a key element in posterolateral stability. Am J Sports Med 1996;24:311-316. 50. Shahane SA, Ibbotson C, Strachan R, Bickerstaff DR. The popliteofibular ligament. An anatomical study of the posterolateral corner of the knee. J Bone Joint Surg Br 1999;81:636642. 51. Sugita T, Amis AA. Anatomic and biomechanical study of the lateral collateral and popliteofibular ligaments. Am J Sports Med 2001;29:466-472. 52. Apsingi S, Nguyen T, Bull AM, Unwin A, Deehan DJ, Amis AA. A comparison of modified Larson and ‘anatomic’ posterolateral corner reconstructions in knees with combined PCL and posterolateral corner deficiency. Knee Surg Sports Traumatol Arthrosc 2009;17:305-312.
Purpose: To evaluate functional results and knee stability after tensioning of remnant posterior cruciate ligament (PCL) with anterolateral (AL) bundle reconstruction and posterolateral corner (PLC) reconstruction in chronic PCL and PLC injuries. Methods: Between March 2001 and March 2007, 95 patients with chronic PCL injuries combined with PLC injuries underwent tensioning of the remnant PCL with AL bundle reconstruction and PLC reconstruction. Among these 95 patients, 70 who were satisfied with our inclusion were reviewed. The mean follow-up period was 40.1 months (range, 24 to 96 months). Tensioning of remnant PCL fibers was performed by distal transfer of the posterior tibial attachment. The AL bundle of the PCL was reconstructed by use of the modified inlay technique. The PLC reconstructive procedure was performed with a single sling through fibular tunnel. Stability was measured on posterior stress radiographs and by use of a maximal manual displacement test performed with a KT-1000 arthrometer (MEDmetric, San Diego, CA). The International Knee Documentation Committee and Orthopädishe Arbeitsgruppe Knie scoring systems were used for clinical evaluation. Results: Stress radiographs showed that the mean side-to-side difference (posterior tibial translation compared with that of the contralateral knee) was reduced from 10.3 ⫾ 2.4 mm preoperatively to 2.2 ⫾ 1.5 mm at the last follow-up (P ⬍ .001), whereas the KT-1000 tests showed that this difference was reduced from 8.4 ⫾ 2.2 mm preoperatively to 2.0 ⫾ 1.4 mm (P ⬍ .001). The final International Knee Documentation Committee objective score was A in 30 patients (42.8%), B in 34 (48.6%), and C in 6 (8.6%). The mean Orthopädishe Arbeitsgruppe Knie score improved from 63.5 ⫾ 10.4 to 88.9 ⫾ 7.6 (P ⬍ .001). Conclusions: Excellent posterior stability and relatively good clinical results were achieved with tensioning of the remnant PCL and AL bundle and PLC reconstruction by use of fibular tunnel for patients with chronic combined PCL-PLC injuries. Level of Evidence: Level IV, case series.
A
lthough arthroscopic instruments and surgical technique are advanced, the most effective arthroscopic posterior cruciate ligament (PCL) reconstruction method has not been well established. It is
From the Department of Orthopaedic Surgery, Medical Center of Chung-Ang University, Seoul, Republic of Korea. Supported by Chung-Ang University research grants in 2009. The authors report no conflict of interest. Received September 26, 2009; accepted November 4, 2010. Address correspondence to Young-Bok Jung, M.D., Department of Orthopaedic Surgery, Medical Center of Chung-Ang University, 224-1, Heukseok-dong, Dongjak-ku, Seoul, 156-755, Republic of Korea; E-mail: [email protected] Crown Copyright © 2011 Published by Elsevier Inc. on behalf of the Arthroscopy Association of North America. All rights reserved. 0749-8063/9576/$36.00 doi:10.1016/j.arthro.2010.11.007
generally known that the PCL has higher healing potential than the anterior cruciate ligament because of a rich blood supply (near the branch of the middle genicular artery) and coverage with a thicker synovium.1,2 Initially after an acute PCL injury, magnetic resonance imaging (MRI) shows a discontinuity of the PCL, but even without surgical intervention, the discontinuity improves.3,4 Recently, a remnant bundle preservation technique has been reported.5,6 The remaining structures of the PCL potentially benefit from enhancement of the revascularization, potentially preserving the proprioceptive function by use of the mechanoreceptors in the original PCL, in addition to adding to the mechanical stability of the knee joint.7,8 Starting in 1998, the senior author has used a modified inlay technique that tensions the anterolateral (AL) bundle of the remnant PCL. This procedure could
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apply for chronic cases at least 6 to 9 months after the initial PCL injury, in those that have lax but relatively good continuity and thickness in the original PCL fibers. The PCL is the primary restraint to posterior tibial translation and a secondary restraint to external tibial rotation.9,10 In addition, the posterolateral corner (PLC) has been shown to play a critical role in restraining external tibial rotation.11,12 It is well established that the PCL and the PLC work synergistically to limit both posterior tibial translation and external tibial rotation.9,12-14 Injury to the PLC structures of the knee can cause posterolateral rotatory instability (PLRI), a condition that has attracted increased attention over recent years. This injury is often associated with cruciate ligament injury, and its diagnosis can be difficult unless one has a high degree of clinical suspicion for an injury to the PLC structures.15,16 PLC injuries are now widely acknowledged as a major factor contributing to poor results in the overall treatment process, particularly if there is a concomitant cruciate ligament injury.10 In addition, it has been shown that failure to treat injuries to the PLC places the knee at risk for continued instability and the development of premature degenerative arthritis, even with a surgically reconstructed PCL.13,17 Although a number of treatment methods have been proposed over the past 20 years, there has been considerable controversy regarding the optimal method of surgical treatment for this injury.15,18-22 We thought that tensioning of the remaining fibers would improve the posterior stability of the knee joint. The purpose of this study was to evaluate the 2- to 8-year results of 70 chronic PCL and PLC reconstructions performed by a single surgeon with a minimum follow-up of 24 months (range, 24 to 96 months). We hypothesized that combined PCL reconstruction with additional reconstruction of the PLC structures would yield significantly improved knee function without serious complications. METHODS Patient Selection and Evaluation Between March 2001 and March 2007, the senior author performed arthroscopic PCL reconstruction surgery on 157 knees. The PCL injuries were graded according to the following scale: grade 1, partial tears of the PCL; grade 2, isolated, complete tear of the PCL; and grade 3, tear of the PCL with other associated ligament injury. Grade 3 PCL injuries were indi-
cated for surgical treatment when the patients had persistent pain or functional disability (discomfort on going down stairs). Chronic (⬎6 months) combined PCL-PLC injury cases that underwent PCL reconstruction by use of tensioning of the remnant PCL with AL bundle reconstruction by the modified inlay technique and posterolateral corner sling (PLCS) (PLC reconstruction by the fibular head tunnel) were included in this study cohort. Thirty patients who had undergone PCL reconstruction with acute or subacute injuries (⬍6 months) and thirty-two patients who had undergone double-bundle PCL reconstruction were excluded. Of the remaining 95 patients, 16 were excluded because they met 1 of the following exclusion criteria: (1) combined anterior cruciate ligament (ACL) reconstruction, (2) an associated fracture in the lower extremities of such magnitude that knee function could be affected, (3) combined severe life-threatening medical disease, and (4) revision surgery. Nine patients were lost to followup, which left 70 patients who met the inclusion criteria and could be followed up for a minimum of 24 months. The study was approved by the institutional review board of our hospital, and all patients provided informed consent. There were 62 male and 8 female patients aged 31.2 years on average (range, 16 to 59 years). The mean duration of the follow-up after surgery was 40.1 months (range, 24 to 96 months). The mean duration from the time of injury to PCL reconstruction was 23.7 months (range, 6 to 240 months). At the time of surgery, all PCL injuries were confirmed grade 3 lesions. Twelve patients were found to have a medial collateral ligament injury at evaluation. Abnormal articular cartilage surfaces were identified during the operation in 12 patients. The areas of cartilage damage were the patellofemoral compartment in 2 patients and the medial tibiofemoral compartment in 10 patients. Medial meniscal injuries were found in 8 patients, with lateral meniscal injuries in 2 patients. All patients had combined PLRI with grade 2 PLC injury. Only those cases with grade 2 PLC injury were enrolled in our series because PLC reconstruction was not indicated for grade 1 PLC injuries, and we used anatomic PLC reconstruction using the fibular head and the tibial tunnel simultaneously for cases with grade 3 PLC injury. We classified the PLC injuries according to varus and rotator instability, as assessed by the varus stress test, dial test, and posterolateral drawer test.23 For varus instability, the difference in the lateral joint space distance and the presence or absence of a firm end point were assessed and classi-
PCL RECONSTRUCTION AND PLCS IN CHRONIC INJURY fied as follows: grade 1, when the difference was less than 5 mm; grade 2, 5 to 10 mm with a firm end point; and grade 3, greater than 10 mm without a firm end point. To assess the degree of PLRI, we conducted the posterolateral drawer test at 30° and 90° of knee flexion as follows: with the thigh held by an assistant to prevent external rotation, the thumb of the examiner was placed in front of the lateral tibial plateau and the remaining fingers were placed in the popliteal space while external rotation force was applied to the ipsilateral foot by the contralateral hand. The thigh-foot angle and patella-tubercle angle were measured with a goniometer. Because of the difficulty of measuring small angles, the minimum measurement unit was set to 5°. The degree of rotation was compared with that of the contralateral side and was easily accessed by observing the position of the tibial tuberosity. The posterior subluxation of the lateral tibial plateau was considered to be more meaningful than the degree of rotation. The classification of PLC injuries was as follows: grade 1, increased external rotation by 5° to 10° compared with the contralateral side, without any varus instability; grade 2, increased external rotation by 10° or greater or posterolateral subluxation of the tibial plateau combined with grade 0 to 2 varus instability; and grade 3, increased external rotation by 10° or greater without a firm end point, combined with grade 3 varus instability from lateral collateral ligament injury (Table 1). There was 1 patient with genu recurvatum and a corrective osteotomy was performed first. Four bundles of autogenous hamstring were used as a graft in AL bundle reconstruction of the PCL in 66 patients, an Achilles allograft tendon in 3 patients, and a tibialis anterior allograft tendon in 1 patient. Autogenous hamstring tendon was used for tendon graft for PLC reconstruction in 65 patients, tibialis anterior allograft in 3 patients, and tibialis posterior allograft in 2 patients. Surgical Technique All patients underwent tensioning of the remnant PCL with AL bundle reconstruction and PLCS (PLC
TABLE 1. Grade 1 Grade 2 Grade 3
Grade of PLC Injury
ER* ⬍10° without varus instability ER ⱖ10° or posterolateral tibial subluxation ⫹ grade 0-2 varus instability ER ⱖ10° or posterolateral tibial subluxation ⫹ grade 3 varus instability
*Degree of external rotation compared with contralateral side.
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reconstruction by the fibular head tunnel) performed by the senior author. Our surgical technique has been described elsewhere,6,24,25 and we describe here specific technical aspects of arthroscopically assisted PCL-PLC reconstruction. The femoral tunnel is made by an outside-in technique without removal of the remnant PCL. The desired femoral tunnel is placed 5 to 6 mm proximal to the margin of the articular cartilage of the medial femoral condyle at approximately the 12:30- to 1-o’clock position on the right knee and at the 11- to 11:30-o’clock position on the left. A femoral tunnel is made without damage to the remnant PCL bundle, and a 21-gauge wire loop is passed through the femoral tunnel, directed just toward the medial side of the remnant PCL of the tibia, and later used to pass the graft from the PCL tibial insertion area into the femoral tunnel. For the posterior approach to the knee, the operating table is tilted over 30° and the knee is flexed 70° to 90° to provide easier access to the popliteal area. After a posteromedial approach, a tibial attachment of the PCL is demarcated as a 1.5 ⫻ 2– cm area by use of an osteotome, and a 7-mm-thick bone block is detached from the distal to proximal area by use of a 1.2- to 1.5-cm-wide curved osteotome. A bony trough is made at the medial side of the PCL tibial insertion just distal to the portion of the bone-block– detached site, to which the detached bone block and graft are to be fixed. Autogenous hamstring 4-bundle graft is passed through the knee joint into the femoral tunnel and fixed on the cortical bone of the distal and medial side of the tibial insertion of the PCL with a 10-mm staple or post-tie. Then, the remnant PCL is tensioned by pulling the bone block distally by use of a stitch of No. 5 nonabsorbable Ethibond suture (Ethicon, Somerville, NJ). The step-off as anatomic reduction is confirmed and the remnant PCL bone block is fixed on the bone block to the tibia by use of a 5- or 6.5-mm cannulated screw with a spiked washer. The operating table is changed back to the neutral position, and the graft is cyclically loaded in tension with 15 to 20 lb and is fixed with a biodegradable interference screw at the femoral tunnel with the knee joint in 70° to 90° of flexion and also fixed with a 10-mm staple or post-tie on the femoral side. Finally, the knee joint is assessed once more to determine whether full extension and flexion are possible without any resistance. PLC reconstruction was performed by our modification of the fibular tunnel method originally described by Larson.26 Two separate 2- to 3-cm incisions were made transversely over the lateral epicondyle
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and obliquely over the fibular head. The fibular tunnel was prepared to a 5- to 6-mm tunnel depending on the graft size obliquely from the anteroinferior to posterosuperior aspect on the fibula with the aid of the ACL guide. Protecting with a curette helped prevent injury to the peroneal nerve, when the fibula head is reamed. The isometric point was examined after insertion of a guide pin at a point 5 to 7 mm anterior and distal to the lateral epicondyle of the femur. After confirmation that the isometric point was less than 3 mm in maximum flexion and extension, the femoral tunnel, with the same diameter of the 4 stranded grafts, was enlarged and chamfered with a rasp. The hamstring tendon autograft was passed through the fibula head tunnel, under an iliotibial band in a figure-of-8 pattern. The grafts were fixed with a bioabsorbable interference screw, at the femoral tunnel, during an 8- to 10-lb tension state in neutral rotation and 70° of flexion of the knee after 20 times cyclic loading while the foot was supported, to negate the effect of traction on the graft by the weight of the leg (Fig 1). Rehabilitation Postoperative rehabilitation varied in each patient according to the rigidity of graft fixation, the degree of isometry, and the results of the final intraoperative stress test after reconstruction. Because the PLC reconstructions were performed at the same time as the PCL reconstructions, passive range-of-motion exercises usually were started on the third to fifth postoperative day. Passive range of motion was attempted while the surgeon or patient held the proximal tibia to avoid posterior displacement by gravity. In addition, passive-assisted exercises were performed in the prone position. The range of motion was increased from 0° to 90° during the first 6 weeks.
The knee was immobilized with a long leg removable splint for 2 to 3 weeks after surgery, followed by a PCL brace until the sixth postoperative week. The goal was to regain full range of motion before the 12th to 24th postoperative week. The patients maintained partial weight bearing for 6 weeks and progressed to full weight bearing in extension, as pain permitted. Stationary bicycling was allowed from the seventh week onward. Strengthening of the hamstring muscles was not allowed until the fourth month after surgery, because the action of the hamstrings could potentially have a negative effect on the PCL and PLC structures. Progressive rehabilitation exercises were performed thereafter, which included not only muscle strengthening but also an adaptation strategy for anticipated activities. Patient Assessment Serial postoperative evaluations were performed at 6 weeks; at 3, 6, and 12 months; and every 12 months thereafter. To evaluate the stability of the knee, a posterior stress radiograph (push view), obtained with a Telos stress device (Telos, Marburg, Germany), and a maximum manual displacement test with the KT1000 arthrometer (instrumented drawer testing; MEDmetric, San Diego, CA) were used preoperatively and at every follow-up after the third postoperative month. The posterior stress radiograph was obtained with a force of 150 N with the knee flexed to 90°. The difference between the involved and contralateral limbs was recorded. The maximum manual displacement test with the KT-1000 arthrometer was performed with the knee flexed to 70°, by pushing the tibia posteriorly before performing a maximum manual anterior drawer test. To evaluate the functional results, the knee scoring systems of the Orthopädishe Arbeitsgruppe
FIGURE 1. Schematic diagrams of PLC reconstruction using fibular head tunnel.
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Knie (OAK) and the International Knee Documentation Committee (IKDC) were used. All evaluations were made by 1 observer who had not been involved in the operation. For assessment of PLRI, the posterolateral drawer test, dial test, and varus stress test were performed at every follow-up, and the results compared with the results of evaluation of the contralateral side. Statistical Analysis Statistical analysis of the clinical results in the mean scores according to the OAK system between the preoperative and the last follow-up evaluations was performed by use of paired t test. The Wilcoxon signed rank test was used to determine the significance of differences between the preoperative evaluations and evaluations at last follow-up, mean side-to-side differences as shown on posterior stress radiographs, and maximum manual displacement test results. All statistical analyses were carried out with SAS software, version 9.13 (SAS, Cary, NC). P ⬍ .05 was considered significant. RESULTS Stability The mean side-to-side difference in posterior translation, as measured by posterior stress radiography, was 10.3 ⫾ 2.4 mm preoperatively and 2.2 ⫾ 1.5 mm at the last follow-up. At the last evaluation, 40 patients (57.1%) exhibited displacement of less than 3 mm, 26 (37.1%) had between 3 and 5 mm of displacement, and 4 (5.7%) showed displacement exceeding 5 mm (Fig 2). The difference between the last follow-up evaluation value and the value before the reconstruction was significant (P ⬍ .001). The mean side-to-side difference as measured by the maximal manual test with the KT-1000 arthrometer was 8.4 ⫾ 2.2 mm preoperatively and 2.0 ⫾ 1.4 mm at the last follow-up evaluation. At the last evaluation, 44 patients (62.9%) exhibited less than 3 mm of displacement, 25 (35.7%) had between 3 and 5 mm of displacement, and 1 (1.4%) had more than 5 mm of displacement. The difference between the value after the last follow-up relative to the value before the reconstruction was significant (P ⬍ .001) (Table 2). At the last evaluation, rotational stability was assessed according to different knee flexion values (30° and 90° of flexion): 14 patients (20%) were overconstrained, 50 (71.4%) were constrained, and 6 (8.6%) were lax, as compared with the normal side. Thus
FIGURE 2. (A) Radiographs of 20-year-old man in whom PCL injury occurred while playing soccer. The stress test using the Telos device shows that there is a 13-mm side-to-side difference posteriorly on the radiograph. (B) Posterior stress radiographs at 5 years’ follow-up after the tensioning of the remnant PCL with reconstruction of the AL bundle and PLC reconstruction showed a 3-mm side-to-side difference posteriorly. In terms of function, the patient continues to engage in sports activity.
91.4% of the patients had achieved restoration of external rotational stability. In terms of varus instability, 2 patients (2.9%) were grade 1 and 68 (97.1%) were grade 0, as compared with the normal side. Clinical Results When the IKDC evaluation form was used, 30 patients (42.8%) were rated as A (normal), 34 (48.6%) as B (nearly normal), and 6 (8.6%) as C (abnormal). Hence, 91.4% of the patients had a rating of A or B at the last evaluation. The mean value of the IKDC
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K-H. LEE ET AL. Outcome Analysis in Terms of Stability Preoperative (N ⫽ 70)
Last Follow-up (N ⫽ 70)
10.3 ⫾ 2.4 0 0 43 (61.4%) 27 (38.6%) 8.4 ⫾ 2.2 0 2 (2.9%) 55 (78.6%) 13 (18.6%)
2.2 ⫾ 1.5 40 (57.1%) 26 (37.1%) 4 (5.7%) 0 2.0 ⫾ 1.4 44 (62.9%) 25 (35.7%) 1 (1.4%) 0
Stress view* ⬍3 mm 3-5 mm 6-10 mm ⬎10 mm KT-1000† ⬍3 mm 3-5 mm 6-10 mm ⬎10 mm
jective IKDC form, and OAK score of 92 points) at the time of the latest follow-up.
P Value
DISCUSSION
⬍.001
⬍.001
NOTE. The score is given as No. of cases (%) or mean ⫾ SD. *Posterior stress radiographs using Telos stress device (G. Scheuba, M.D.). †Manual maximum displacement test with knee flexed at 70° by use of KT-1000 arthrometer (instrumented drawer testing).
subjective score was 79.7 ⫾ 13.3 (range, 64 to 99). The mean OAK score was 63.5 ⫾ 10.4 (range, 42 to 86) preoperatively and 88.9 ⫾ 7.6 (range, 67 to 100) postoperatively. At the last evaluation, 31 patients (44.3%) were classified as excellent, 30 (42.8%) as good, 7 (10%) as fair, and 2 (2.9%) as poor. Thus 87.1% of the patients had a good or excellent rating at the last evaluation. The difference between OAK scores before reconstruction and at last follow-up evaluation was significant (P ⬍ .001) (Table 3). Complications There was 1 patient with intraoperative complications during PLCS from injury to the peroneal nerve, which sustained direct damage by the reamer or guide pin. Our patients had complete recovery at final follow-up. During the early period of this study, 1 patient sustained an incomplete fracture of the fibular neck when we constructed the fibular tunnel. The fracture was not addressed because there was acceptable stability of the graft after reconstruction, and the patient had grade 1 PLRI at final follow-up. We thought that the fracture of the fibular neck resulted from a transverse tunnel; thus we made an oblique tunnel, and thereafter the fracture has not recurred. In another patient, PLRI and varus instability recurred 2 years after the operation. On physical examination, grade 3 PLRI was found to present. Thus anatomic PLC reconstruction by grafting through the fibular head and the tibial tunnel simultaneously was performed. The patient had a good clinical outcome score (grade A on objective IKDC form, 82 points on sub-
The principal findings of this study showed that combined PCL-PLC instabilities can be successfully treated with simultaneous reconstruction of PCL and PLC structures. It included only chronic cases treated by the same PCL-PLC reconstruction technique with relatively larger numbers by a single surgeon. Most patients recover a functionally stable knee with considerably improved knee function as noted by both subjective criteria and objective measurement methods. Recently, there has been an increased understanding of the biomechanics and function of the PCL and PLC, an improvement in the investigation of these injuries. New techniques of reconstruction have been developed, but reports of the results remain limited.18,27-29 There are several clinical series reporting results of PLC reconstruction combined with PCL reconstruction. In 1996 Noyes and Barber-Westin17 reported 3 fully functional cases, 1 partially functional case, and 5 cases of failure in 9 knees undergoing combined PCL reconstruction and proximal advancement of the lateral collateral ligament and the PLC, with follow-up of 23 to 90 months. In 2002 Wang et al.30 reported on 25 patients who all had transtibial single-bundle PCL reconstruction and PLC reconstruction by the technique of Larson26 plus some additional lateral collateral ligament advancement, with overall satisfactory results in 68% of patients and restoration of ligament stability in 44%. In 2003 in the series of Kim et al.31 of 25 patients with PLRI
TABLE 3.
OAK Excellent Good Fair Poor IKDC subjective IKDC objective A B C D
Outcome Analysis of Clinical Score Preoperative (N ⫽ 70)
Last Follow-up (N ⫽ 70)
63.5 ⫾ 10.4 0 1 (1.4%) 17 (24.3%) 52 (74.3%) 50.6 ⫾ 16.8
88.9 ⫾ 7.6 31 (44.3%) 30 (42.8%) 7 (10%) 2 (2.9%) 79.7 ⫾ 13.3
0 0 42 (60%) 28 (40%)
30 (42.8%) 34 (48.6%) 6 (8.6%) 0
P Value ⬍.001
⬍.001 ⬍.001
NOTE. The score is given as No. of cases (%) or mean ⫾ SD.
PCL RECONSTRUCTION AND PLCS IN CHRONIC INJURY combined with PCL injuries, all had transtibial singlebundle PCL reconstruction and PLC reconstruction by use of biceps tenodesis, with satisfactory results based on IKDC scores in 76%, and restoration of external rotational stability in 64%. In 2004 Fanelli and Edson18 reported a series of 41 patients who all had transtibial single-bundle PCL reconstruction with Achilles allograft, biceps tenodesis, and posterolateral capsular shift, with satisfactory posterior stability in 70% and restoration of external rotational stability in 98%. In our series of 70 patients, all underwent PCL reconstruction combined with PLC reconstruction with the fibular tunnel technique, with satisfactory results in 91% by IKDC scores and in 87% by OAK scores, as well as restoration of external rotational stability in 91%. Our results, especially in terms of the stability, were much improved compared with the previously mentioned series. This may be because of several reasons. First, tensioning of the remnant PCL probably produced better stability. Most PCL injuries occur with the knee in flexion; when they happen, the AL bundle of the PCL is tensed and severed whereas the posteromedial bundle and meniscofemoral ligament remain intact.32,33 In addition, it is known that the PCL has better synovial coverage, blood circulation, and spontaneous healing potential than does the ACL. Many MRI studies3,4,34 and an experimental animal study35 have shown that an acute ruptured PCL has healing potential. Therefore the PCL seems to have spontaneous healing potential even in the case of rupture at the substance, although it leaves laxity. Safran et al.7 reported that the mechanoreceptors in PCL-injured knees act as knee stabilizers, which explains why degenerative changes develop more slowly in patients with posterior instability than in those with anterior instability. Therefore, if the remnant of the PCL is not resected but is tensioned surgically, there would be an advantage of preserving the proprioceptive function of the mechanoreceptor in a continuous PCL and stability as similar as possible to the normal PCL. On the basis of this fact, we hypothesized that the tensioning of the remnant PCL fibers and augmentation of the AL bundle would contribute to posterior knee stability. We recommend this technique for chronic cases at least 6 months after the initial PCL injury, in those that have a good density and 50% to 60% thickness in the remnant PCL bundles as shown by MRI. If the remnant PCL is very weak and narrow, we recommend a double-bundle PCL reconstruction. The second possible reason is that the tibial inlay technique produced better stability than the transtibial technique. Many surgeons have suggested that, in a
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reconstruction of the PCL, the excessive angular deformity of the graft at the posterior opening of the tibial tunnel—the so-called killer turn or killer curve36-38—may result in failure and stretching of the graft. Berg36 described popliteal fossa exposure with tibial inlay reconstruction as a solution to this problem. This procedure allows secure direct fixation to the posterior proximal tibia. In a biomechanical comparison of the transtibial and tibial inlay technique, Bergfeld et al.37 and Markolf et al.38 described more severe wearing and loosening of the graft with transtibial PCL reconstruction after cyclic loading, supporting the efficacy of tibial inlay reconstruction in achieving posterior stability of the knee. Until recently, many authors have described numerous tibial inlay techniques, as well as their advantages and good clinical outcomes.27,39 However, the disadvantage of the tibial inlay technique is that access to the anterior and posterior knee with a position change is necessary during the surgical procedure. We also found that exposing the popliteal fossa is difficult with the patient in the lateral decubitus position. Therefore, we choose to use a modified inlay technique that facilitates the posteromedial approach by table tilting at 30° down on the affected side.25,40 The third important factor includes diagnosis and treatment of the posterolateral rotator instability. PCL injuries are associated commonly with PLC injuries.41-43 Biomechanical studies have shown that cutting the posterolateral structures increases the in situ forces on the PCL.13,44 Recurrent laxity after PCL reconstruction is most commonly related to untreated PLC injuries.32,43,45 Thus great efforts have been made to find the appropriate diagnosis and treatment for PLC injuries. However, a uniformly accepted approach has yet to be established. We used both the posterolateral drawer test and dial test for diagnosis of PLRI. In posterolateral drawer test, the posterior subluxation of the lateral tibial plateau was checked as well as the degree of the tibial external rotation. To assess the degree of rotation accurately, the posterolateral drawer test and dial test was performed with reduction of a posteriorly subluxated tibia. If the knee is examined in a state of altered anatomic positioning, a PLC injury may potentially be missed. In a combined PCL-PLC–injured knee, a reduced force applied to the tibia increased the overall amount of observed tibial external rotation during the dial test.46,47 This means that many patients may not be treated if they are borderline grade 1 or 2 in the subluxated position of the knee. More recent studies have shown that the popliteofibular ligament plays a key role in resistance to pos-
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terior translation, varus stress, and external rotation, and this ligament’s reconstruction should be incorporated into any surgical technique used to correct PLRI of the knee.48-51 The fibular tunnel sling technique described in this series approximates the anatomy of the static portion of the popliteofibular ligament and the fibular collateral ligament (FCL). In our procedure the posterior portion was designed to re-create the popliteofibular ligament and the anterior portion was designed to re-create the FCL. The fibular tunnel has advantages in that it can be easily visualized, and the skin incision is shorter. In addition, biomechanically, the FCL reconstructed by the fibular head tunnel method more closely approximates the anatomy of the natural FCL, and it is thought that a sling pulled outward anterior to the fibular head may be biomechanically superior. Theoretically, a popliteofibular graft should be more effective in controlling external rotation than a popliteus graft because it is fixed at a greater distance from the axis of tibial rotation, thus giving it a greater mechanical advantage. LaPrade et al.20 and Chang et al.48 have reported that “anatomic” PLC reconstruction is necessary to improve the clinical results of PLC reconstruction; however, Apsingi et al.52 have reported that the anatomic reconstruction did not perform better than the 2-strand technique. We have had some experience with a popliteal bypass procedure: the localization of the tibial tunnel is somewhat inaccurate, and thus it requires the help of image amplifiers. Furthermore, because the posterior tibial tunnel orifice is placed too deep, graft passage may be sufficiently difficult so that the surgical time is increased.24 Thus we recommend that the PLC reconstruction by use of fibular tunnel is simpler, is biomechanically superior, and causes less surgical morbidity than a tibial tunnel method when PLRI concomitant to PCL injury was less than 2°. However, for cases with 3° of PLC injury, one should consider repairing the injuries anatomically by grafting through the fibular head and the tibial tunnel simultaneously. Our study suffers from some limitations, including (1) a relatively short-term follow-up period, (2) the absence of a control group with a different surgical technique for PCL-PLC injuries, and (3) the lack of evaluation of proprioception. In addition, this study was retrospective and not a randomized controlled trial. Therefore the reason for the improvement in the stability and clinical results cannot be defined precisely. On the other hand, our study comprises a relatively large series of chronic PCL and PLC injuries objectively evaluated by use of multiple knee scores as well as stress radiography and
KT-1000 arthrometer, performed by a single surgeon. Moreover, considering the aforementioned potential benefit, tensioning of the remnant fiber and simultaneous PLC reconstruction might be worthwhile in chronic PCL-PLC injuries.
CONCLUSIONS Tensioning of the remnant PCL with AL reconstruction and PLC reconstruction by use of the fibular tunnel in chronic PCL and PLC injuries greatly restored posterior stability and improved the function of the knee. REFERENCES 1. Bray RC, Leonard CA, Salo PT. Vascular physiology and long-term healing of partial ligament tears. J Orthop Res 2002;20:984-989. 2. Scapinelli R. Vascular anatomy of the human cruciate ligaments and surrounding structures. Clin Anat 1997;10:151-162. 3. Shelbourne KD, Jennings RW, Vahey TN. Magnetic resonance imaging of posterior cruciate ligament injuries: Assessment of healing. Am J Knee Surg 1999;12:209-213. 4. Tewes DP, Fritts HM, Fields RD, Quick DC, Buss DD. Chronically injured posterior cruciate ligament: Magnetic resonance imaging. Clin Orthop Relat Res 1997:224-232. 5. Ahn JH, Yang HS, Jeong WK, Koh KH. Arthroscopic transtibial posterior cruciate ligament reconstruction with preservation of posterior cruciate ligament fibers: Clinical results of minimum 2-year follow-up. Am J Sports Med 2006;34:194-204. 6. Jung YB, Jung HJ, Tae SK, Lee YS, Yang DL. Tensioning of remnant posterior cruciate ligament and reconstruction of anterolateral bundle in chronic posterior cruciate ligament injury. Arthroscopy 2006;22:329-338. 7. Safran MR, Allen AA, Lephart SM, Borsa PA, Fu FH, Harner CD. Proprioception in the posterior cruciate ligament deficient knee. Knee Surg Sports Traumatol Arthrosc 1999;7:310-317. 8. Jung YB, Jung HJ, Yang JJ, et al. Characterization of spontaneous healing of chronic posterior cruciate ligament injury: Analysis of instability and magnetic resonance imaging. J Magn Reson Imaging 2008;27:1336-1340. 9. Grood ES, Stowers SF, Noyes FR. Limits of movement in the human knee. Effect of sectioning the posterior cruciate ligament and posterolateral structures. J Bone Joint Surg Am 1988;70:88-97. 10. Veltri DM, Deng XH, Torzilli PA, Warren RF, Maynard MJ. The role of the cruciate and posterolateral ligaments in stability of the knee. A biomechanical study. Am J Sports Med 1995;23:436-443. 11. Kurtz CA, Sekiya JK. Treatment of acute and chronic anterior cruciate ligament-posterior cruciate ligament-lateral side knee injuries. J Knee Surg 2005;18:228-239. 12. Sekiya JK, Haemmerle MJ, Stabile KJ, Vogrin TM, Harner CD. Biomechanical analysis of a combined double-bundle posterior cruciate ligament and posterolateral corner reconstruction. Am J Sports Med 2005;33:360-369. 13. Harner CD, Vogrin TM, Hoher J, Ma CB, Woo SL. Biomechanical analysis of a posterior cruciate ligament reconstruction. Deficiency of the posterolateral structures as a cause of graft failure. Am J Sports Med 2000;28:32-39. 14. Veltri DM, Deng XH, Torzilli PA, Maynard MJ, Warren RF. The role of the popliteofibular ligament in stability of the
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