Prof. Dr. Ahmed Abdelaziz Professor of Orthopedic Surgery Faculty of Medicine Cairo University

Transcription

1 Comparative study between anatomic single bundle and anatomic double bundle ACL reconstruction Thesis submitted for fulfillment of MD degree in orthopedic surgery By Ahmed Mahmoud Mohamed Gad Assisstant lecturer of orthopedic surgery Faculty of Medicine Cairo University Supervised by Prof. Dr. Ahmed Abdelaziz Professor of Orthopedic Surgery Faculty of Medicine Cairo University Prof. Dr. Ibrahim Elgeiedy Professor of Orthopedic Surgery Faculty of Medicine Cairo University Prof. Dr. Omar Soliman Assisstant Professor of Orthopedic Surgery Faculty of Medicine Cairo University Dr. Ahmed Rizk Mohamed Lecturer of Orthopedic Surgery Faculty of Medicine Cairo University 2012

2 ABSTRACT Both groups were comparable regarding age distribution at the time of the operation. At post-operative assessment of both groups, the total score on the Lysholm knee scale averaged points in the single-bundle group and points in the double bundle group, with no statistically significant differences. Comparing both groups regarding IKDC scoring parameters, revealed a statistically insignificant difference in the number of patients in the single-bundle group when compared to doublebundle group regarding all parameters. KT-1000(side to side differences) measurements averaged 3.98 mm in the SB group and 3.15 mm in the DB group, but the difference was statistically insignificant. A 3D motion analysis system was used to measure the concerned kinematic parameters (knee extension moment & internal tibial rotation angle). The absolute side to side differences analysis revealed a statistically significant difference between both groups regarding the knee extension moment (p=0.04) but no statistically significant differences between group A and group B regarding the differences in internal tibial rotation angle. Key words Comparative study between anatomic single bundle and anatomic double bundle ACL reconstruction

3 Acknowledgement Thanks for Allah who showed me the way. I would like to express my deep gratitude and thanks to Prof. Dr. Ahmed Abdel Aziz to whom I owe an immeasurable dept for his continuous support throughout my career. Also I would like to thank my supervisors: Prof. Dr. Ibrahiem Elgeiedy, professor of Orthopedic Surgery, Faculty of Medicine, Cairo University, Prof. Dr. Omar Soliman, assistant professor of Orthopedic Surgery, Faculty of Medicine, Cairo University and Dr. Ahmed Rizk, lecturer of Orthopedic Surgery, Faculty of Medicine, Cairo University for their sincere help and guidance to bring up this study to completion. Last and not least, thanks to my parents...you are always my backup.

4 I Contents Introduction 1 Anatomy... 4 Biomechanics. 23 Gait Analysis Diagnosis. 38 Clinical Evaluation.. 79 Rehabilitation.. 87 Materials & Methods Results. 130 Discussion Summary. 179 Conclusion Refrences 182

5 II List of figures Figure Content Page no. no. 1 Front view of a left knee showing the ACL in the femoral intercondylar notch. 5 2 ACL crosssectional area 5 3 ACL physiological impingement 7 4 Right knee joint from anterior showing the two ACL bundles 8 5 Cadaveric model showing bundle tightness in flexion & extension 10 6 The femoral attachment of the AM and PL bundles of the ACL 11 7 Scopic view showing the lateral bifurcate and intercondylar ridges 12 8 The insertion site for the ACL on the tibia 13 9 Schematic drawing of the tibial plateau illustrating the tibial insertion of 14 the AM and PL bundles of the ACL in the axial plane. 10 Tibial insertion sites of AM and PL bundles Thin transverse section of ACL fascicles Longitudinal paraffin section of a human ACL fibre bundle 17 13(a,b) Toluidine blue stained histological sections of the ACL femoral origin vascular anatomy of ACL with angiogram Changes in shape and relative tension of the anterior and posterior 26 portions of the anterior cruciate ligament in extension and 90 of flexion 16 The relative position of the two bundles & femoral insertion site with the flexion 27 angle of the knee 17 The intersegmental flexion-extension moment The patellar ligament insertion angle (PLIA) Lachman test stable Lachman test prone Lachman test 45 22(a,b) The no touch Lachman test & active Lachman test Anterior drawer test in 90º flexion Pivot shift test Modified pivot shift test The McMurray test The posterior drawer test Quadriceps contraction test KT-1000 arthrometer 57 30(a,b) X-rays showing Lateral capsular sign & Segond fracture inercondylar tubercle and interconylar notch osteophytes Normal ACL. Sagittal fat suppressed proton density MRI Normal ACL. Coronal fat suppressed proton density MRI Acute ACL rupture. Sagittal fat suppressed proton density MR image Chronic ACL rupture. Sagittal fat suppressed proton density MR image ACL rupture. Coronal fat suppressed proton density MR image Secondary bone bruise associated with ACL rupture. Coronal fat 67 suppressed proton density MRI 38 Secondary bone bruise associated with ACL rupture. Sagittal fat suppressed 68 proton density MRI 39 Anterior tibial translation as secondary sign of ACL ruptures Anterior tibial translation as a secondary sign of ACL ruptures 72

6 III 41 Anterior tibial translation as a secondary sign of ACL ruptures Examination under anaethesia Empty notch (torn ACL) (a,b) Graft harvesting (a,b) Graft preparation (group A cases) Femoral endobutton with continuous polyester loop (a,b) Graft preparation (group B cases) Accessory anteromedial portal Visualization of LFC through AL portal Visualization of LFC through AM portal Measuring femoral foot print Insertion of femoral guide pin ASB femoral tunnel Tibial guide aimer (outside view) (a,b) ASB tibial tunneling Graft passage (ASB) Graft passage (ASB) (a,b) Drilling AM femoral tunnel Anatomical posterolateral femoral aimer (Smith &Nephew) Drilling PL femoral tunnel ADB reconstructed femoral tunnels The anatomic PL tibial guide aimer (Smith & Nephew) ADB tibial tunnels drilling ADB tibial tunnels drilling ADB tibial tunnels drilling (a,b) Passage of PLB (a,b) Bundles check in flexion (a) & extension (b) Postoperative x-ray of an ASB ACL reconstruction Postoperative x-ray of an ADB ACL reconstruction Motion capture unit The force plate unit & reflective markers The force plate unit & reflective markers Age groups of group A and group B Total Lysholm score pre & post operative group A patients Total Lysholm score pre & post operative group B patients Total Lysholm Knee score post operatively in group A &B patients Lachman test in group A pre and post-operatively Pivot shift test in group A pre and post-operatively Lachman test in group B pre and post-operatively Pivot shift test in group B pre and post-operatively Post-operative Lachman test (both groups) Post-operative Pivot Shift test (both groups) Distribution of cases of KT-1000 side to side difference measurements of 157 group A and group B 84 Comparison of mean KT-1000 side to side difference measurements of 158 group A and group B 85 Knee extension moment analysis (comparing both groups) Internal tibial rotation angle (comparing both groups) 161

7 IV

8 IV List Of Tables Table Content Page 1 Lysholm knee scoring scale 80 2 IKDC) scale 83 3 ACL reconstruction rehabilitation protocol 89 4 Group A patients clinical data 93 5 Group B patients clinical data 93 6 Demographic data of group A and group B The Clinical data of group A and group B pre-operative and post-operative Lysholm score (components 132 & total score) of group A 9 Limp score pre & post operative - group A patients: Support score pre & post operative - group A patients Locking score pre & post operative - group A patients Instability score pre & post operative - group A patients Pain score pre & post operative - group A patients Swelling score pre & post operative - group A patients Stair climbing score pre & post operative - group A patients Squatting score pre & post operative - group A patients: Total Lysholm score pre & post operative - group A patients preoperative and postoperative Lysholm score (components & 138 total score) of group B 19 Limp score pre & post operative - group B patients Support score pre & post operative group B patients Locking score pre & post operative - group B patients Instability score pre & post operative group B patients Pain score pre & post operative - group B patients Swelling score pre & post operative - group B patients Stair climbing score pre & post operative - group B patients Squatting score pre & post operative - group B patients Total score pre & post operative - group B patients post-operative Lysholm score (components & total score) of 144 group A and B 29 Grades of knee effusion pre and post operatively - group A Lack of extension and flexion pre and post operatively - group 147 A 31 Lachman test and Pivot shift test in group A pre and postoperatively One leg hop test pre and post operatively group A Grades of knee effusion pre and post operatively - group B Lack of extension and flexion pre and post operatively 151

9 V 35 Lachman test and Pivot shift test in group B pre and postoperatively One leg hop test pre and post operatively - group B Grades of knee effusion post operatively Both groups Lack of extension and flexion post operatively Both groups Lachman test and Pivot shift test in both groups postoperatively 155 Both groups 40 One leg hop test post operatively Both groups the KT-1000 measurements of group A and group B Kinematic motion analysis of operated and non-operated 159 limbs - Group A 43 Kinematic motion analysis of operated and non-operated 159 limbs 44 Kinematic motion analysis of operated and non-operated limbs of group A and B 160

10 VI List Of Abbreviations AAM... Accessory anteromedial ACL...Anterior cruciate ligament ADB...Anatomic double bundle AL...Anterolateral AM...Anteromedial AMB...Anteromedial bundle ASB...Anatomic single bundle DB Double bundle DOF.Degrees of freedom Gs.Gracillis LFC..Lateral femoral condyle MFC.Medial femoral condyle PCL..Posterior cruciate ligament PL.Posterolateral PLB..Posterolateral bundle PLC..Posterolateral corner SB...Single bundle ST...Semitendinosus 2D...Two dimensional 3D...Three dimensional

11 1 INTRODUCTION Anterior cruciate ligament reconstruction is one of the most common arthroscopic procedures performed in orthopeadic surgery nowadays. (1) Anterior cruciate ligament reconstruction with standrard single bundle techniques provide satisfactory subjective results and restores anteroposterior stability in the vast majority of patients in the short term. Long term results of the operation have not yet been defined and some authors believe that such ligament reconstruction does not protect the knee joint from osteoarthritis. Moreover, many authors have clinically detected residual minimal rotatory instability in almost a fifth of cases independent of the graft, surgical technique and choice of fixation device. So, it s evident that single bundle ACL reconstruction does not perfectly restore normal knee kinematics. (2) The fact that so many different methods have been described for reconstruction of ACL in patients with functional instability indicates the ideal solution to this problem has not yet been found. (3) Several solutions have been proposed to increase rotational control of reconstructed graft including a more horizontal graft orientation as through a lower femoral tunnel entry point (such as 10 o clock position). (2) The concept of anatomical double-bundle (DB) ACL reconstruction was introduced recently to restore the anatomy and biomechanical function of the native ACL. (4) Anatomical and biomechanical studies have shown that the ACL comprises two principal bundles; the anteromedial bundle and posterolateral bundle. According to anatomical and biomechanical studies, the separate reconstruction of the anteromedial (AM) and posterolateral (PL) bundle was supposed to increase the overall postoperative stability and clinical results compared to single-bundle (SB) ACL reconstruction. (5)

12 2 Conventional single bundle techniques of ACL reconstruction have focused usually on the restoration of the anteromedial bundle while paying limited attention to the posterolateral bundle. An anatomical SB procedure is performed by placing one single bone tunnel in the centre of the tibial and femoral ACL footprints. The bone tunnels are drilled according to the diameter of the prepared graft without considering the relationship between the size of the natural insertion site area and the reconstructed one. This results in a randomized percentage of surgically restored ACL footprint. However, several biomechanical studies demonstrated that ACL fibres of different parts of the insertion sites add different to knee function. Fibres attached to the tibial anteromedial part of the ACL footprint (AM-bundle fibres) add more to anterior stability compared to PL bundle fibres which add more to rotational stability close to extension. (4) In evaluating this topic (double-bundle reconstruction) one should consider several areas, including anatomic, biological and biomechanical aspects as well as clinical outcomes. There is a general agreement that ACL has (functional bundles) and the tension is variable among the fiber bundles within the ligament across the range of motion. Anatomical studies used cadaveric knees, arthroscopy and MRI are needed to describe the presence, insertion sites, size, shape, length and rupture pattern of the anteromedial and posterolateral bundles in order to provide guidelines for anatomical reconstruction. (1) Biological considerations include the study of tendon graft heeling within bone tunnels to identify optimal graft sizes and rehabilitation programs. The biomechanical evaluation should reveal the different functions of each bundle for rotatory and anteroposterior knee stability in different angles of knee flexion.

13 3 Finally, the clinical outcomes using clinical parameters such as range of motion, Lachman grade, anterior drawer grade, pivot shift grade, objective measurement of knee laxity as obtained with KT 1000 and Scores such as International knee documentation committee (IKDC) and Lysholm scores should be routinely applied. (1) The aim of this study was to evaluate the clinical outcome of four-tunnel ADB ACL reconstruction with hamstring tendons compared to ASB ACL reconstruction in a prospective randomized trial. The hypothesis of the study was that DB ACL reconstruction might be clinically advantageous in regaining anterior and rotational stability compared to SB ACL reconstruction. Both groups were compared regarding the following parameters; clinical evaluation according to the Lysholm and the IKDC rating scoring systems, postoperative arthrometric evaluation and kinematic knee motion analysis comparing operated and non operated limbs.

14 4 GROSS ANATOMY The cruciate ligaments are unique as they are the only ligaments of the knee that are intracapsular but extrasynovial. These ligaments appear crossed (hence "cruciate") on viewing the knee anteriorly or laterally. The ACL is a cord-like complex structure with well-defined tibial and femoral attachments that maintain a portion of the ligament taut during the full range of motion of the knee. (6) The ACL has a simple predictable parallel fiber arrangement with consistently matched origins and insertions of individual fibers within the attachment as a whole. Fibers that originate superiorly on the femur insert anteriorly on the tibia and those that originate inferiority insert posteriorly. Central fibers keep their relative orientation throughout the ligament. (7) I-Fiber orientation and ligament cross-sectional area: The ACL is lateral to the midline and occupies the superior 66% of the lateral aspect of the notch on an anterior view of the flexed knee joint. The size of the bony attachment can vary from 11 to 24 mm. (8) The average length of the ACL is 31 to 38 mm, the average thickness is 5-mm and the average width at midpoint is 11 mm (7 to 15 mm). (9) The cross sectional area varies along the ACL length, with the largest cross-sectional area at the tibial attachment distally. It is irregular and not circular, elliptical or any other simple geometric form. This shape changes with the angle of flexion, but is generally larger in the anterior posterior direction. It increases from the femur to the tibia, as follows: 34 mm 2 proximally, 33 mm 2 mid-proximally, 35 mm 2 at mid-substance level, 38 mm 2 mid-distally, and 42 mm 2 distally (fig.1-2). (10)

15 5 Fig.1 Front view of a left knee showing the ACL in the femoral intercondylar notch. The mean length is 32 mm (range, mm) and the mean width is 10 mm (range, 7 12 mm). (10) Fig.2 The crosssectional area varies in size and shape from the femur to the tibia. (10)

16 6 In addition, according to the anatomy studies reported by Odensten and Gillquist (1989) who examined insertions of the anterior cruciate ligament, the diameter of the femoral insertion varies from 18±2 mm to 11±2 mm while the diameter of the tibial insertion varies from 17±3 mm to 11±2 mm. The average cross-sectional area of the main bundles is 44.4 to 56.5 mm 2. (11) Harner et al (1999) evaluating five human cadaveric knees, reported an average anteromedial (AM) bundle attachment area of 47 and 56 mm 2 on the femur and tibia, respectively. The posterolateral (PL) bundle attachment area was on average 49 mm 2 on the femur and 53 mm 2 on the tibia. This is because of fanning pattern of both insertions. No significant differences could be detected between the two bundles in terms of dimensions. Using two strands to reconstruct the anterior cruciate ligament enables an insertion surface area closer to the anatomic situation. (12) The axis of the long diameter of the ACL is tilted 26 ± 6 forward from the vertical. (11) During its course in the joint, the ligament seems to turn itself in a lateral spiral. This external rotation is approximately 90 as the fibers approach the tibial surface. The twist of the fibers of the ACL is a result of the orientation of its bony attachments. The femoral attachment is oriented primarily in the longitudinal axis of the femur whereas the tibial attachment is in the antero-posterior axis of the tibia. (13) The ACL tibial attachment fans out and forms a foot region. This allows the ACL to tuck under the roof of the intercondylar notch. In full extension the anterior fibers of the ACL turn around the anterior edge of the intercondylar notch. This bending is considered as a physiological impingement. This specific anatomy causes concern for ACL reconstruction since common grafts do not posses such a part of the tibial ACL insertion and tends to impinge with the notch in slight degrees of flexion. Notch impingement due to anterior tibial tunnel positions is a common cause for postoperative extension block (fig.3). (14)

17 7 Fig.3 Because of the anatomical shape of the insertion areas at the femoral and tibial insertion site, anterior fibers of the ACL are able to bend around the anterior edge of the intercondylar notch. Common reconstruction techniques do not replicate the foot type insertion at the tibia. A straight graft (dotted lines) such as a bone patellar tendon bone or hamstring graft may impinge at the notch in knee positions close to extension. (14) II-Bundles structure: Functionally, it is composed of anteromedial and posterolateral bands and possible an intermediate band. These divisions are important because each appears to have a separate function, with the posterior band tight in extension and the anterior one tight in flexion (fig.4). (9) Although there are several publications describing 3 bundles of the ACL, the AMB, PLB, and intermediate bundle, in fact, the latter could only be identified in some specimens, not in all. It is often identified as a part of the AMB; it cannot be constantly identified and divided separately. However, the ACL can be divided into 2 bundles in all specimens. (15)

18 8 Fig.4 Right knee joint from anterior. The patellar tendon and the surrounding soft tissue have been removed to inspect the ACL. Note the 2 distinct bundles, the AM and PL bundles. (9) Duthon et al (2006) noted that the fascicles of the AMB originate at the most anterior and proximal aspect of the femoral attachment and insert at the anteromedial aspect of the tibial attachment. Conversely, the fascicles of the PLB originate at the posterodistal aspect of the femoral attachment and insert at the posterolateral aspect of the tibial attachment. A larger number of fascicles make up the PLB as compared to the AMB. (4) With the knee in extension, the fascicles of the ACL run in a fairly parallel fashion when viewed sagittaly. During flexion, there is a slight lateral rotation of the ligament as a whole around its longitudinal axis, and the AMB begins to spiral around the rest of the ligament. This relative movement of one bundle upon the other is due to the orientation of the bony attachments of the ACL. (4) The length and orientation of the ACL fibers have been reported to change throughout passive flexion and extension as well as tibial internal and external rotation.

19 9 The length of the ACL fibers ranges from 22 mm to 41 mm with a mean of 32 mm. However, these measurements are more for the AM bundle. (16) Kummer and Yamamoto measured the intraarticular length of the PL bundle in 50 cadavers and reported a length of 17.8 mm. (17) According to the tensioning pattern, the distance for the AM bundle increases with flexion. Takai and coworkers reported an increase of 3.3 mm at 90 of knee flexion. The length of the PL bundle however, was decreased at 90 of flexion when compared with full extension (fig.5). (18) Amis and Dawkins reported that an internal tibial rotation lengthened the fibers more than external rotation, which was most pronounced at 30 of flexion. (19) For ACL reconstruction and femoral tunnel placement, the fiber length is affected more by varying the femoral attachment. Moving the tibial location had only a small effect; however anterior-posterior and proximal-distal variations at the femoral insertion site had strong effects on length patterns. (20)

20 10 Fig.5 Cadaveric model with the medial femoral condyle removed: (A) The AM bundle is taut in 90 of flexion; (B) the PL bundle is taut with the knee in extension. (18)