Update on ACL reconstruction, with information on current direction of demineralized bone matrix (DBM) use in bone tunnels and biocartilage on chondral lesions

1. Update on the ACL
Alan M. Hirahara, M.D., FRCS(C)
Board Certified in Orthopaedic Surgery & Orthopaedic Sports Medicine
Specializing in arthroscopic shoulder surgery
Medical Director Team Physician Consultant
Sacramento State Athletics Sacramento River Cats Oakland A’s
MiLB - AAA

2. Anterior Cruciate Ligament Mechanisms
of Injury
• Hyperextension
• Hyperflexion
• Valgus-Rotation

3. Instability Tests
• Examine contralateral leg
• Relax the patient
– Difficult with acute injuries / Re-examine
• Gentle then repeat several times to determine
maximum stress tolerated
• Degree of instability
• Quality of instability (“End Point”)

4. Anterior Drawer
Even with anesthesia, only accurate 50%

5. Lachman Test
Most sensitive test and diagnostic 95% of time

6. Pivot Shift
• Anterolateral instability
• Lateral tibial plateau
subluxes in extension
• Reduces in flexion by IT
band
Grade I – Glide into place
Grade II – Pops into place
Grade III – Doesn’t reduce

7. Associated Pathology
• Meniscal tears (62%)
– Acutely – Lateral
– Chronic – Medial
• Osteochondral fractures (10 - 20%)
• Other ligamentous injuries (19%)

8. Xray
• Segund sign
– Lateral capsular sign
– Avulsion fracture,
indicating lateral capsular
injury associated with
ACL rupture

9. MRI

10. Partial ACL Tear
Empty Lateral Wall Sign

11. Treatment
• Conservative management
– Build up quads & hams
– ACL Brace
– Avoid pivot sports
• Reconstruction
– No meniscal repair without reconstruction

12. Fixation for ACL: Soft Tissue

13. Fixation for ACL:
Bone & Soft Tissue
Interference Screws – Metal vs. Bioabsorbable vs. BioComposite

14. ACL Reconstruction:
Hamstrings / Transfix

15. ACL Reconstruction:
Animation of All-Inside TightRope

16. Results of ACL Recon
• Meta-analysis • Allograft comparable to
demonstrates newer autograft for long term
techniques with 4HS vs. stability
BTB produces higher – But debatable whether less
stability rates and are morbidity
– 1 : 1.5 to 4 million risk of
fixation dependent
disease transmission
– 77 – 80% Normal stability
– 4.4 – 5.9% Instability rates
Prodromos et al, Arthroscopy, 21(10) 2005.
Sherman et al, Arthroscopy, 20(9) 2004.

17. STIMUBLAST

18. Demineralized Bone Matrix
• Allograft bone with inorganic mineral removed, leaving only organic
collagen matrix
• Increased osteoinductivity
– Exposed growth factors (BMP’s)
• Requires a carrier
• Many clinical studies showing efficacy but each product has different
characteristics

19. DBM
Osteoinduction
Carrier Terminal
Product Distributor Assay – Test
% DBM (by wt) Sterility?
Every Lot?
RPM Yes In Vivo
StimuBlast Arthrex
(36) E-Beam Yes
Wright CaSO4 Yes In Vitro
AlloMatrix
Medical (40) E-Beam Yes
Na Hyaluronate In Vivo / In Vitro
DBX Synthes No
(32) Yes
Glycerol In Vivo
Grafton Medtronic No
(17) No

20. Reverse Phase Medium (RPM)
• Mod Pluronic F127 (Poloxamer PPO PEO)
5 min
• More viscous at body temp
• Resists irrigation, can use arthroscopically
• Permeable to blood, resorbed
• Metabolized readily
RPM Glycerol

21. The Problem

22. Etiology of ACL Tunnel Widening
Biological Mechanical
• Synovial fluid propagation • Graft position
• Increased cytokine levels • Fixation method
• Sterilization methods
• Implant material
• Graft type
• Graft donor
Maak et al. JAAOS. 2010; 18: 695-706.
Fauno et al. Arthoscopy. 2005; 21(11): 1337-41.
Wilson et al. AJSM. 2004; 32(2): 543-9.
Darabos et al. Knee Surg Sports Traum Arthrsc; 2011; 19: S36-46.
Rodeo et al. AJSM. 2006; 34(11): 1790-800.

23. Potential Consequences
• Delaying incorporation of the soft tissue graft
into bone
• Decreasing graft stability
• Causing difficulty with future revision surgery

24. Saw Bones Testing

25. A Pilot Study:
Effect of DBM on tunnel size
in ACL reconstruction
Alan M Hirahara, MD, FRCSC

26. Study Design
Study Control
• 14 patients • 6 patients
– 7 male / 7 female
– 3 male / 3 female
– Age mean: 28.9 (15 – 45 yo)
– Age mean: 26.6 (16 – 48 yo)
• 5 revisions
– 2 staged / 3 primary • No revisions
• Associated pathology
• Associated pathology
– 2 meniscus repair
– 2 menisectomy
– 5 menisectomy
– 3 chondroplasty – 2 microfx chondroplasty

27. VAS Results
6.0
5.0
4.0
3.0
2.0
1.0
0.0
Pre-op Month 1 Month 2 Month 3 Month 4 Month 5 Month 6
Study Control

28. Technique

29. 3 Months Post-op

30. The effect of biologic treatments on
ACL reconstruction tunnel widening
– a randomized clinical trial
Investigators:
Alan Hirahara MD, FRCSC, Private Practice, Sacramento CA
Thomas M. DeBerardino, MD, U of Connecticut Health Center

31. BIOCARTILAGE

32. Micronized Cartilage ECM
• Potential augment for Microfracture
– Provides cartilage ECM scaffold
– Allows for BM MSC attachment and growth
– Stem Cells exposed to ECM will differentiate based on factors present within the matrix
– Glycoproteins/Proteoglycans
– Simple / inexpensive
• Cheng et al (Tissue Engineering 2009)
– Adult stem cells seeded onto the lyophilized cartilage scaffold
– Chondrogenesis of ASCs evident by PCR & immunohistochemical examination
– Resembled native articular cartilage
Cheng N et al. Tissue Engineering 2009.

33. Relative Costs
Competition BioCartilage (Arthrex)
• ACI (Genzyme) • $750 – Morselized, freeze-
– $10,000 – Cost for cultured dried cartilage
cells
– + Costs of two surgeries
• DoNovo (Zimmer)
– $4,000 – Live cells

34. BioCartilage: Trochlea (Knee)

35. Thank You!