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 ConsultantSacramento State Athletics Sacramento River Cats Oakland A’s MiLB - AAA
Anterior Cruciate Ligament Mechanisms of Injury• Hyperextension• Hyperflexion• Valgus-Rotation
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”)
Anterior DrawerEven with anesthesia, only accurate 50%
Lachman TestMost sensitive test and diagnostic 95% of time
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
ACL Reconstruction:Animation of All-Inside TightRope
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.
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
DBM Osteoinduction Carrier Terminal Product Distributor Assay – Test % DBM (by wt) Sterility? Every Lot? RPM Yes In VivoStimuBlast Arthrex (36) E-Beam Yes Wright CaSO4 Yes In VitroAlloMatrix Medical (40) E-Beam Yes Na Hyaluronate In Vivo / In Vitro DBX Synthes No (32) Yes Glycerol In Vivo Grafton Medtronic No (17) No
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
The effect of biologic treatments onACL reconstruction tunnel widening – a randomized clinical trialInvestigators:Alan Hirahara MD, FRCSC, Private Practice, Sacramento CAThomas M. DeBerardino, MD, U of Connecticut Health Center
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.
Relative CostsCompetition 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