Current trends in ACL surgery include a shift towards anatomical reconstruction techniques that more closely restore the native ACL footprint. While double bundle reconstruction aims to better restore knee rotation, high quality studies show no difference in outcomes compared to single bundle reconstruction. Autograft tissue like hamstring tendon is preferred over allograft for younger patients due to higher failure rates with allograft. Postoperative rehabilitation protocols emphasize early range of motion restoration and return to sport is recommended between 8 to 12 months following surgery accompanied by meeting specific strength and performance benchmarks.

1. CURRENT TRENDS IN ACL
(Anterior Cruciate Ligament ) SURGERY
1

2. OUTLINE
Background
Anatomy
Treatment options (non-surgical, sb: single bundle, db: double
bundle)
Techniques
Graft types
Rehabilitation
Summary
2

3. ACL INJURIES
 ACL tears account for up to 64% of athletic knee injuries in cutting and
pivoting sports.
 120,000–200,000 ACLRs performed annually in the United States.
 Acute ACL injuries: joint effusion, altered knee kinematics and gait, muscle
weakness, and reduced functional performance
 Long term sequelae: meniscal tears, chondral lesions, and posttraumatic
osteoarthritis.
3

4. ANATOMY
4

5. ANATOMY
Double bundle :
 Anteromedial (AM)
 Posterolateral (PL)
Ribbon-like midsubstance
Lateral intercondylar ridge
Lateral bifurcate ridge
5

6. ANATOMY
 Tibial C-shape insertion runs from
along the medial tibial spine to the
anterior aspect of the anterior root of
LM
 No ACL fibers inserted in the center of
the “C” nor posterolateral (which was
the place of the bony attachment of
the anterior root of the LM)
 No PL bundle was found but
posteromedial (PM) fibers
6
Rainer Siebold. Tibial C-Shaped Insertion of the Anterior Cruciate Ligament Without Posterolateral Bundle.
ESSKA 2014.

7. TREATMENT OPTION
7

8. TREATMENT OPTION
Non-operative management - poorly tolerated by both adults and
young patients
Leads to recurrent instability, chondral and meniscal injuries
People participating in sports or work related activities that
require a lot of pivoting, cutting, or jumping may decide to have
surgery
8
Stannard JP. AAOS Orthopaedic Knowledge Update 12. Ch. 36. 2017
Ajuied A. AJSM 2014

9. SURGICAL VERSUS CONSERVATIVE INTERVENTIONS FOR TREATING
ANTERIOR CRUCIATE LIGAMENT INJURIES
• No differences between surgical management (ACL reconstruction
followed by structured rehabilitation) and conservative treatment
(structured rehabilitation only) in patient-reported outcomes of
knee function at 2-5 years after injury.
• Many participants with an ACL rupture remained symptomatic following
rehabilitation and later opted for ACL reconstruction surgery
9
Cochrane Database of Systematic Reviews 2016, Issue 4. Art. No.: CD011166.

10. ACL RECONSTRUCTION – TIMING
 ACL reconstructions performed beyond 3 weeks post-injury were at
significantly lower risk of developing arthrofibrosis
 ACL reconstruction should preferably be performed within 6 months
from injury to avoid the risk of additional damage (LM in acute setting
and MM as time elapses)
10J Bone Joint Surg Am. 2010 Dec 1;92(17):2767-75
Shelbourne et al. AJSM 1991

11. ACL RECONSTRUCTION – TIMING
 An increase in the number and grade of cartilage lesions with increasing time
from injury is a consistent finding especially MFC
 Skeletally immature patients are at a similar risk of developing secondary
lesions and should be prioritized for ACL reconstruction with appropriate
physeal-sparing techniques
11
Knee Surg Sports Traumatol Arthrosc. 2004 Jul;12(4):262-70
Am J Sports Med. 2014 Nov;42(11):2560-6

12. TECHNIQUE
12

13. NON-ANATOMIC ACLR
• Traditional ACLRs are placing the graft outside of the native insertion of the
ACL. (clockwise ref.)
• Vertically oriented grafts able to reconstitute stability in the sagittal plane
(anterior-posterior) but fail to provide adequate rotational stability.
• Non-anatomic tunnel placement can alter the forces experienced by the graft
and is one of the main reasons grafts fail (continued instability or re-rupture)
after ACLR.
13
Arch Bone Joint Surg 2016;4:291-7.

14. NON-ANATOMIC ACLR
14

15. NON-ANATOMIC ACLR
15

16. ANATOMIC ACLR
attempt to restore the native ACL footprint on both the tibial and
femoral sides of the knee to recreate the native functional
kinematics
Single bundle (SB) reconstruction is indicated for
 tibial insertion sites less than 14 mm in length,
 narrow notches (less than 12 mm in width)
 concomitant ligamentous injuries
 severe bone bruising
 severe arthritic changes (KL3-4)
 in the setting of open physis
16Arthroscopy 2010;26:258-68.

17. SB ANATOMIC ACLR
17

18. ANATOMIC ACLR
Double bundle (DB) reconstruction - considered in patients
with
 a large tibial insertion site (anteroposterior length >14 mm)
 large intercondylar notch (length and width >14 mm)
 absence of concomitant ligament injuries
 absence of advanced arthritic changes (KL <3)
 absence of severe bone bruising
 closed physis
18Arthroscopy 2010;26:258-68

19. DB ANATOMIC ACLR
19(2005) Arthroscopy 21:1402.e1–1402.e5

20. DB ANATOMIC ACLR
20Rainer Siebold’s C Type Ribbon Technique ESSKA 2014

21. SB vs DB ACLR
 DB ACLR is to reconstruct both the AM and PL bundles, more closely
reproducing the native knee anatomy and kinematics
 Biomechanical promise of DB fails to translate into clinical significance and
may predispose the graft to impingement and excessive tension through the PL
bundle during knee extension, resulting early graft rupture or attenuation
 When patients are individually assigned based on the size of the ACL native
insertion site and the intercondylar notch width, prospective studies demonstrate
no difference in terms of anteroposterior and rotational laxity between single or
double-bundle reconstruction techniques
21
Arch Bone Joint Surg 2016
Am J Sports Med 2012;40:1781-8.
Paschos NK, Howell SM. EFORT Open Rev 2016

22. SB vs. DB ACLR
22
T. Järvelä and R. Siebold. in Anterior Cruciate Ligament Reconstruction
ESSKA 2014

23. TUNNEL DRILLING
 Transtibial technique is falling more out of practice (decreased from
56.4% in 2007 to 17.6% in 2014) as a growing number of surgeons perform
an outside-in technique or use guides placed through the AM portal
(increased from 41.3% in 2007 to 65.1% in 2014)
 Outcome data including fewer persistently positive Lachman and pivot shift
tests, lower KT-1000 scores, and higher Lysholm scores in the transportal
groups further support this paradigm shift.
23
J Bone Joint Surg Am 2016;98:1079-89.

24. Various types of interference screws used for ACLR (Titanium, Bio,
HA-coated: Right to left)
24

25. ROLE OF FIXATION DEVICE
25Cureus. 2015 Nov; 7(11): e378

26. FIXATION TYPE
no clear consensus on superiority of aperture, suspensory
cortical, or button graft fixation or screw (metal/biologic) versus
button graft fixation.
Biologic screws can be associated with tunnel widening, a complication
infrequently observed in metallic screw fixation. However, biologic
screws allow for advanced imaging of the knee postoperatively without
metal artifact.
26
Bone Joint Surg Am 2016;98:1079-89

27. FIXATION TYPE
Decrease in use of first-generation bioabsorbable screws for graft
fixation and a shift toward biocomposite fixation
When securing soft tissue grafts, recent studies favor suspensory
fixation which fosters better junctional bone-tendon healing as
well as stronger zero time fixation
27
Stannard JP, Sherman SL, Cook JL. Soft tissues about the knee. In: Grauer JN, editor.
AAOS Orthopaedic Knowledge Update 12. Ch. 36. 1-13. 2017.

28. ACL remnant preserving
Intact remnants played an important role in mechanical strength in the
early postoperative period
Reservation of the blood supply aid in the healing process of the graft
Maintenance of proprioceptive innervation with evident benefits for the
subjective outcome and return to sports
Optimization of the accuracy of the procedure by improving the
arthroscopic orientation and bone tunnel placement at the insertion site
28
Knee Surg Sports Traumatol Arthrosc. 2012 Feb;20(2):245-51

29. GRAFT TYPES
29

30. Allograft vs. Autograft
Selection should be based on patient factors
(patient age, skeletal maturity, and activity level)
2.6x higher rate of failure when using allograft vs autograft in patients
<25 years
Allograft - acceptable outcome in middle-aged or recreational athlete
Allograft – need longer time for graft ligamentization
30
Stannard JP, Sherman SL, Cook JL. Soft tissues about the knee.
AAOS Orthopaedic Knowledge Update 12. 2017

31. PROS AND CONS OF VARIOUS GRAFTS USED FOR ACL
RECONSTRUCTION
31

32. GRAFT TYPES
HT - equivalent functional outcomes and less donor-site morbidity,
but increased risk of failure/revision, persistently positive pivot shift
test, diminished return to preinjury levels of activity, and higher
rates of infection
BPTB - strong stiff graft, secure fixation, bone-to-bone healing, and
low failure rates, but higher incidence of anterior knee pain and
kneeling pain
32
Am J Sports Med 2014.

33. GRAFT TYPES
QT - good strength, low donor-site morbidity, and reliable long term
outcomes
Quadriceps is an ACL antagonist, slightly impaired function of this
muscle may protect the ACL graft against the quadriceps anteriorly
directed force
Biomechanical studies demonstrate that the residual strength of the
QT after graft harvest is higher than that of the intact PT.
33
Knee Surg Sports Traumatol Arthrosc 2017 Mar 21. 26 (2), 418-425.
Arthroscopy. 2009 Feb;25(2):137-44

34. REHABILITATION
34

35. REHABILITATION
Pre-op rehabilitation – preserve Q strength and knee ROM
Post-op rehabilitation
 Acute phase - restore ROM ,maintain Q strength, reduce
inflammation (0-3 wks.)
 Recovery phase - improve lower limb muscle strength and
functional stability (3-6 wks.)
 Functional phase - return to previous level of activity and reduce
risk of re-injury (6+ wks.)
35

36. REHABILITATION
Little consensus regarding rehab protocol
Early return to play – increased risk of graft failure and injury to
contralateral native ACL
Return to play when:
 Time from surgery 8-12 months
 Absence of pain and effusion
 ROM comparable to contralateral knee
 Negative Lachman / Pivot shift test
 One leg hop test >85-90% of contralateral
 Drop vertical jump without dynamic valgus
36
Ellman MB et al. JAAOS 2015

37. RETURN TO SPORTS AFTER ACLR
In the first 2 years after ACL reconstruction, 30 % of people who
returned to level I sports sustained a reinjury compared to 8 % of
those who participated in lower level sports.
For every month that return to sport was delayed, until 9 months after
ACL reconstruction, the rate of knee reinjury was reduced by 51%.
More symmetrical quadriceps strength prior to return to sport
significantly reduced the knee reinjury rate.
Only 5.6 % of patients who passed RTS criteria before returning to
level I sports suffered reinjuries compared to 37.5 % of those who
didn’t pass
37
Br J Sports Med 2016;50:804-808.

38. SUMMARY
 ACL reconstruction surgery has evolved considerably over the past few decades.
 Early reconstruction should be followed by accelerated rehabilitation, and delayed
reconstruction is associated with poor outcome.
 Autograft yielded better results than allograft.
 BPTB-R was associated with better postoperative knee stability but with a higher rate of
morbidity.
 However, in terms of functional outcome, both BPTB and hamstring graft were similar in the
long-term
 .Most of modern fixation devices have enough strength to fix the graft in ACL reconstruction
regardless of graft materials.
 All fixation devices have their distinct advantages and disadvantages. Therefore, the choice of a
fixation device should be based on the type of graft or quality of bone. Since there is a variety of
options available today, selection of an optimum combination of the graft as well as fixation
devices should be individualized to the patient’s condition and the experience of the surgeon.
 The double-bundle ACL reconstruction technique showed better outcomes in rotational laxity,
although functional recovery was similar between single-bundle and double-bundle.
 Further advances in surgical techniques should continue to be developed so as to restore near-
normal knee kinematics and anatomy.
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39. Thank You….
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