The Role of the Anterolateral Ligament in Knee Stability

Transcription

1 The Role of the Anterolateral Ligament in Knee Stability Albert O. Gee, MD Assistant Professor Orthopaedics and Sports Medicine University of Washington CU Sports Medicine Fall Symposium September 22, 2017

2 Number of Publications Anterolateral Ligament (ALL) Tremendous interest and research since 2013 Approx 200 publications to date Time

3 Anterolateral Ligament (ALL) There s still a lot of debate Exist? New? What does it do? How do we treat?

4 Why so much confusion?

5 Controversy about Anatomy Anatomy can be subjective Trying to interpret a photo Different terms for the same structures Lateral capsule ligament Mid-third lateral capsular ligament Capsulo-osseous layer Anterolateral ligament Varying dissection techniques

6 Controversy about Anatomy The dissection studies are not consistent Fresh-Frozen vs. Embalmed Specimens Dissection of overlying IT Band Knee flexion at the time of dissection Claes J Anat 2013; Herbst KSSTA 2017

7 Controversy about Anatomy Vincent et al. KSSTA 2012 Claes et al. J Anat 2013 Dodds et al. Bone Joint J 2014 Kennedy et al. AJSM 2015 Variable anatomy of ALL Variable incidence in studies: % Dombrowski, Musahl KSSTA 2016; Dodds JBJS(b) 2014

8 Anatomy Controversy Different dissection = Different analysis Mechanical testing Histology Imaging

9 ALL Biomechanics 10 of 11 fresh cadaver specimens had an ALL Robotic study Serial sectioning method to determine force changes Anterior translation and IR torque tested at various flexion angles Parsons, Gee AJSM 2015; Rasmussen AJSM 2015; Spencer AJSM 2015

10 ALL Biomechanics ALL limits Internal Rotation Flexion >35 degrees Not involved in anterior translation Parsons, Gee AJSM 2015; Rasmussen AJSM 2015; Spencer AJSM 2015

11 Kittl AJSM 2015 ALL Biomechanics IT band is the key structure, not the ALL Superficial and Deep (capsulo-osseous layer) of IT band resist IR & Ant. translation Both Intact and ACL deficient state Kittl, Amis AJSM 2015

12 Agree to Disagree on ALL Existence Anterolateral Complex (ALC) instead of ALL ALC includes: IT Band and its components Underlying anterolateral capsule May or may not have a specific capsular ligament Agree that the complex as a whole is important for rotational stability of the knee Musahl Karlsson KSSTA 2017

13 Sooner or later, everything old is new again

14 Cavaignac, KSSTA 2016 New Ligament or New Name? Pearly, resistant, fibrous band (Segond, 1879) Lateral epicondylomeniscal ligament (Valois, 1914) Mid-third lateral capsular ligament (1976) Capsulo-osseous layer of ITT (1993) Anterolateral ligament (Vincent 2012)

15 Anterolateral rotatory instability (Pivot Shift) Dr. Hughston (1970s and 80s) Pioneer on anterolateral rotatory instability Middle third lateral capsular ligament (1976) Believed injury to this structure important for Pivot Shift (Jerk Test) (Galway, MacIntosh, Kennedy, Fowler, Slocum, Larson all involved in describing rotatory instability and Pivot Shift relating to ACL tears and injury to peripheral structures) Hughston JBJS 1976

16 Anterolateral rotatory instability (Pivot Shift) Dr. Hughston (1970s and 80s) Pioneer on anterolateral rotatory instability Capsulo-osseous layer of the IT Band (Terry 1993)

17 Anterolateral rotatory instability (Pivot Shift) Dr. Hughston (1970s and 80s) Pioneer on anterolateral rotatory instability Capsulo-osseous layer of the IT Band (Terry 1993)

18 Extra-articular tenodesis Due to historical complexity of open ACL surgery Alternative surgical procedures were sought 1913 ITB autograft augment of both collaterals (Giertz) Gained popularity in 1970s ALRI /Pivot shift localizing to capsulo-osseous layer injury

19 Extra-articular tenodesis Marcel Lemaire (1975)

20 Extra-articular tenodesis MacIntosh (1976)

21 Extra-articular tenodesis Andrews Mini (1983)

22 Extra-articular tenodesis Non-anatomic procedures Concerns about over-constraining knee Arthritis Often required long periods of casting Stiffness Outcomes fairly poor across techniques Fell out of favor Evolution toward the modern intra-articular ACL reconstruction techniques Dodds JBJS(b) 2014

23 ACL Reconstruction Advances in knee arthroscopy First arthroscopic reconstruction by Dandy 1980 Schindler J Periop Pract 2012

24 Schindler J Periop Pract 2012 ACL Reconstruction Advances in fixation devices Transfix pins Interference screws Biocomposites Endobutton (1994)

25 Schindler J Periop Pract 2012 ACL Reconstruction More anatomic restoration of the ACL Anteromedial portal drilling Came down on the wall Double bundle reconstruction Back to single bundle Tunnel isometry vs anatomy

26 ACL and ALL Reconstruction?? We still have room to improve on outcomes Return to play estimates are as low as 50% Non-zero failure rate of ACLR (5 20%) Higher young patients and certain sports. Renewed interest in New ALL Ardern AJSM 2012

27 Combined ACLR and ALLR Cadaver biomechanical study Anatomic ALL reconstruction with allograft HS Combined reconstruction needed to restore full stability when ACL and ALL both torn Netri, AJSM 2016

28 Potential Overconstraint? Combined reconstruction decreases native IR at deeper flexion Netri, AJSM 2016

29 Combined ACLR and ALLR Cadaver biomechanics study IT Band tenodesis alone (Getgood) restored stability in combined ALL and ACL sectioned knees Spencer, AJSM 2015

30 Combined ACLR and ALLR Marcacci et al. AJSM 2009 Case Series (N=54) ACLR with HS autograft Over-the top on femur Continuing on to extra-articular tenodesis with staples 11 year follow-up 90% good-excellent outcome scores OA only in those with medial meniscectomy

31 Combined ACLR and ALLR Ferretti et al. Arthroscopy 2016 Retrospective comparative case series ACLR versus ACLR + Extra-articular tenodesis (modified MacIntosh) Minimum 10 year follow-up >90% good-excellent outcome scores (IKDC, Tegner, Lysholm) in both groups No difference in radiographic OA between groups Lower rate of residual pivot shift in combined group

32 Combined ACLR and ALLR Sonnery-Cottet AJSM 2017 Prospective study comparing ACL to ACL+ALL N=541 primary ACLs in 16 to 30 y.o. (more active) ACLR + ALLR was associated with significantly reduced ACL graft rupture (2.5 rate reduction) Non-randomized; Differences existed between study groups potential for selection bias

33 Summary Disagreement continues on the anterolateral ligament Anterolateral complex works with the ACL to provide knee rotation stability Anterolateral complex reconstruction likely has role alongside ACL reconstruction Indications for reconstruction not yet defined

34 Summary Level 5 considerations for use of ALLR (Musahl KSSTA 2017) Revision ACL With primary ACLR in high-grade pivot shift With primary ACLR in high risk patients (younger, cutting sports) Further studies are needed Multi-center RCT of ACL plus Extra-articular tenodesis (Getgood) Other factors in rotational laxity other than ACL Capsule, Meniscus, Bony morphology of joint surfaces

35 Thank You