ACL Injury Hacks covers the entire physiology, etiology,pathology, diagnosis, recent advancements in diagnosis of ACL and focus on how an early and accurate diagnosis can contribute to a better treatment and rehabilitation as well as early return to sport of an athlete.

1. ACL Injury Hacks
Dr. Dhruv Taneja (PT)
M.P.T (Msk & Sports), PhD Scholar
Associate Professor
Jaipur Physiotherapy College
Maharaj Vinayak Global University
Chief of Physiotherapy & Rehabilitation:
The Royal Orthopedic Hospital and Sports Injury Center
Jaipur, Rajasthan

2. ACL Injury
 Stability Factors
 Introduction
 Knee Anatomy
 Functions of ACL
 Risk Factors
 Grades
 Differentials
 Diagnosis/Tools

3. Knee Joint Stability

4. Introduction
Incidence is higher in Sports
involving Jumping and
landing — such as
•Soccer, Basketball, Football,
Downhill skiing.
•Many people hear or feel a
"pop".
•Your knee may swell, feel
unstable and become too
Dhillon M S, John R, Sharma S, Prabhakar S, Behera P, et al.
Epidemiology of Knee Injuries in Indian Kabaddi Players, Asian
J Sports Med. 2017 ; 8(1):e31670. doi: 10.5812/asjsm.31670

5. Anatomy
 The ACLiscomposedof denselyorganized,
fibrous collagenousconnectivetissuethat
attaches the femur to the tibia.
 2 groups:
- Antromedial band
- Posterolateral band

6. Attachment
 On the Femur,theACLisattached to:
a fossaonthe posteromedial edge of the lateral femoral
condyle.

7. Attachment
 On theTibia, theACLisinserted to:
 Anteriortibial marginand blendswithAnt. HornofMedial Meniscus
Nerve Supply: posterior articular branches of the tibial nerve
Blood Supply: Middle Geniculate Artery
Duthon VB, Barea C, Abrassart S, Fasel JH, Fritschy D, Ménétrey J. Anatomy of the anterior cruciate ligament. Knee
Surg Sports Traumatol Arthrosc. 2006 Mar;14(3):204-13. Epub 2005 Oct 19.

8. FunctionsofACL
 primary (85%) restraint to limit anterior
translation of the tibia.
 secondaryrestraint to tibial rotation and
varus/valgus angulation at full extension.
 Lesser degree: the ACL checks extension
and hyperextension.
 The average tensilestrengthfor theACLis 2160
N.

9. RiskFactor to ACLtear
High-risk sports:
football, baseball, soccer,skiing,and basketball
Sex:
F> M
Femoralnotchstenosis:
< 0.2 (NWI)
Footwear:

10. Reasoning on Risk Factors
Why F>M
 Women have a lesser cross section
area for ACL than men.
 Men have larger Quadriceps and
hamstring size which directly relates
to load bearing on the knee joint.
NWI (Notch Width Index) <0.20
Robert F. LaPrade, MD, and Quinter M. Burnett II, MD.The American journal of
Sports medicine: Vol.22, No.2 Femoral Intercondylar Notch Stenosis and
Correlation to Anterior Cruciate Ligament Injuries:

11. GRADES

12. DIFFERENTIALS
Structure Differentiating Signs/Symptoms Differential tests
Medial collateral ligament (MCL)
sprain
•The ‘pop’ less common
• True dynamic instability is rare,
unless it is a complete tear.
• No significant hemarthrosis
•Tender over MCL course/insertion.
•MCL stress testing reveals laxity
and/or pain.
•MRI reveals fluid around or injury to
MCL; ACL appears intact.
• Subsequent x-rays may reveal
calcification along previously injured
MCL (Pellegrini-Stieda disease).
Posterior collateral ligament (PCL)
sprain
•Knee effusion typically smaller and
less noticeable by the patient.
•ACL tests negative
•PCL test positive
•Often able to continue activity but
knee does not feel right subjectively
to the patient.
MRI reveals disrupted PCL, and an
intact ACL.

13. Structure Differentiating Signs/Symptoms Differential tests
Lateral collateral ligament (LCL)
sprain
•Local swelling is common, but
significant effusion is rare.
•Tenderness over theLCL Ligament
and/or bony insertion.
• A complete tear often results in a
palpable gap.
•Spontaneous healing and full return
of function is the rule. [
MRI reveals fluid around or
disruption to LCL, with intact ACL.
Meniscal tear •Pain at affected joint line and
stiffness.
•Positive McMurray test
•Effusion typically develops over 1
to 2 days
•Rapid hemarthrosis with large tear
in vascular portion of meniscus.
•Locked/Rubbery Knee
MRI has excellent sensitivity for
meniscal tears, but intrasubstance
degenerative changes may be
misread as acute tears.

14. Structure Differentiating Signs/Symptoms Differential tests
Posterior capsular sprain Small effusion and stiffness common
along with painful extension.
Imaging rarely necessary. MRI may
show effusion, bone bruising,
abnormal signal at posterior capsule,
but no frank ligament disruption.
Patellar subluxation or dislocation •Severe pain around patella;
•Kneecap off to the side.
•Hemarthrosis with difficulty in weight
bearing
•Sensation of the kneecap being
unstable.
•Apprehension sign positive when
examiner attempts to displace patella
laterally.
•X-rays may reveal dislocation if not
yet reduced, or patellar fracture.
•Lateral subluxation and abnormal
patellofemoral relationship often
noted. MRI often reveals bone
bruising, and may show chondral
injury, osteochondral fracture, or
loose body.

15. Diagnosis/Examination Tools and
Methods
 Clinical Examination
 Radiological Examination
 Arthrometer/Lachmeter
 KT 1000

16. Examinations
1. Inspection:
- immediate effusion >> intra-articular trauma.
2. AssessROM:
Lackof completeextension.
3. Palpation:

17. Clinical Examination : Decision making
Note:
 On cross section area, ACL is twice as thick in athletes than in common population.
 Athletes might not produce the symptoms as does the general population.
 In athletes the size of the ACL differs among men and women.
 Women have a lesser cross section area for ACL than men.
 Men have larger Quadriceps and hamstring size which directly relates to load bearing on the knee joint.
 Correlation of Anthropometric Measurements, Strength, Anterior Cruciate Ligament Size, and Intercondylar Notch
Characteristics to Sex Differences in Anterior Cruciate Ligament Tear Rates. The American Journal of Sports Medicine
F. Anderson, MD, David C. Dome, MD, Shiva Gautam, PhD, Mark H. Awh, MD, Gregory W. Rennirt, MD

18.  Lachmantest: mostsensitivetest

19.  Pivotshift test:

20.  Anterior drawer test : least reliable

21. DIAGNOSIS
The three most studied tests:
 The Lachman
 The Pivot shift
 The Anterior Drawer Test have shown overall adequate accuracy for clinical use.
However, these tests also yielded lower accuracy
 When utilized acutely post injury compared to a chronic tear.
 Combined lesion to the meniscus and other ligaments.
 Tear is partial compared to complete.
Moreover, inter-rater reliability of these tests are lower when executed by non-expert clinicians because of
technical difficulties and interpretation of the outcomes.
1. Decary S Ouellet P Vendittoli PA Roy JS Desmeules F. Diagnostic validity of physical examination tests for common knee disorders: An overview of systematic reviews and meta-analysis. Phys Ther
Sport.2017;23:143-155.
2. Benjaminse A Gokeler A van der Schans CP. Clinical diagnosis of an anterior cruciate ligament rupture: a meta-analysis. J Orthop Sports Phys Ther. 2006;36(5):267-288.
3. van Eck CF van den Bekerom MP Fu FH Poolman RW Kerkhoffs GM. Methods to diagnose acute anterior cruciate ligament rupture: a meta-analysis of physical examinations with and without
anaesthesia. Knee Surg Sports Traumatol Arthrosc. 2013;21(8):1895-1903.
4. Leblanc MC Kowalczuk M Andruszkiewicz N, et al. Diagnostic accuracy of physical examination for anterior knee instability: a systematic review. Knee Surg Sports Traumatol
Arthrosc. 2015;23(10):2805-2813.
5. Lange T Freiberg A Droge P Lutzner J Schmitt J Kopkow C. The reliability of physical examination tests for the diagnosis of anterior cruciate ligament rupture--A systematic review. Man
Ther.2015;20(3):402-411.
6. Decary S Ouellet P Vendittoli PA Desmeules F. Reliability of physical examination tests for the diagnosis of knee disorders: Evidence from a systematic review. Man Ther. 2016;26:172-182.

22. Lever Sign: Lelli’s test
 A more reliable test .
 Lelli et al. proposed a new physical
examination test to diagnose ACL tear
called the Lever sign.
 Place your fist under the calf
 Create a “fulcrum” while extending the
knee
 Apply moderate downward force on distal
femur
 In an intact knee, the ACL completes a
lever mechanism, making the heel rise in
response to the force applied to the
femur.
 In an ACL-deficient knee, the heel does
not rise indicating a positive Lever sign.

23. Limitations
 Severe pain and
tenderness
 Disability
 Edema
 Doubt of associated
injury
 Grading of severity
 Avulsion injury
 False positive test
1. Benjaminse A Gokeler A van der
Schans CP. Clinical diagnosis of an
anterior cruciate ligament rupture: a
meta-analysis. J Orthop Sports
Phys Ther. 2006;36(5):267-288.
2. van Eck CF van den Bekerom MP
Fu FH Poolman RW Kerkhoffs
GM. Methods to diagnose acute
anterior cruciate ligament rupture: a
meta-analysis of physical
examinations with and without
anaesthesia. Knee Surg Sports
Traumatol Arthrosc. 2013;21(8):1895-
1903.
3. Leblanc MC Kowalczuk M
Andruszkiewicz N, et al. Diagnostic
accuracy of physical examination for
anterior knee instability: a systematic
review. Knee Surg Sports Traumatol
Arthrosc. 2015;23(10):2805-2813.
4. Lange T Freiberg A Droge P
Lutzner J Schmitt J Kopkow C. The
reliability of physical examination
tests for the diagnosis of anterior
cruciate ligament rupture--A
systematic review. Man

24. Diagnosis
1st choice
 Clinical Examination
or
 RadiologicalExamination
or
Both together

25.  Imaging Studies:
 - Plain radiographs.
Usually -ve
replaced by MRI -Arthrograms
 - MRI
* Gold standard
* 90-98%sensitivity and
specificity
* Great impact on the diagnosis
and management of ACL injuries
after the MR evaluation.
1. Reicher MA, Bassett LW, Gold RH.
Highresolution magnetic
resonance imaging of the knee
joint: pathologic correlations.
Americ J Roentgenol.
1985;145(5):903-9.
2. 2. Lubowitz JH, Bernardini BJ,
Reid III JB. Current concepts
review: comprehensive physical
examination for instability of the
knee. Americ J sports Medic.
2008;36(3):577-94.
3. 3. Lee JK, Yao LA, Phelps CT, Wirth
CR, Czajka JO, Lozman JE.
Anterior cruciate ligament tears:
MR imaging compared with
arthroscopy and clinical tests.
Radiology. 1988;166(3):861-4.
4. 4. McCauley TR, Moses M, Kier R,
Lynch JK, Barton JW, Jokl P. MR
diagnosis of tears of anterior

29. Presentation of NORMAL ACL
on MRI

32. Partial Tear

33. Complete Tear

34. Frontal View: Normal

35. Frontal View: Tear’s

36. Arthrometer/KT-1000
greater than 3 mmsmeasuredby the KT-1000 is
classified as pathologic.
Passive anterior laxity at the knee was measured using the KT 1000
arthrometer. An anterior force was applied to the knee via the calibrated
handle and the displacement was measured as the difference between the

37. Lachmeter/Rolimeter
Ganko A1, Engebretsen L, Ozer H. The rolimeter: a new arthrometer compared with the
KT-1000. Knee Surg Sports Traumatol Arthrosc. 2000;8(1):36-9.
Balasch H1, Schiller M, Friebel H, Hoffmann F. Evaluation of anterior knee joint instability

38. Conclusion
An Accurate and early diagnosis is the only key
towards a perfect and a better rehabilitation as well as
the key to return back to sports for an athlete.