BY MADDIE PICCIONE Stem Cell Therapy: An Alternative to ACL Surgery

Background on the ACL ACL (anterior cruciate ligament) attaches the tibia and femur Crucial ligament that keeps the knee stable Keeps the knee from sliding backward and forward (femur and tibia rubbing against each other)

ACL Injuries ACL tears occur when the femur and tibia turn in opposite directions Hyperextension of the knee Very common in sports like basketball, soccer, football and skiing

Severity of ACL Injuries Grade 1 Sprain: ACL undergoes a partial tear and becomes loose, resulting in some knee instability. Grade 2 Sprain: ACL is completely torn into two pieces, but still stay together (non-retracted) Grade 3 Sprain: ACL is completely torn into two separate pieces and they pull apart (retracted)

Severity of ACL Injuries (contd)

Typical ACL Reconstruction Surgery A graft is needed to act as the temporary ACL and provide a scaffold for the new ACL to grow on  Autografts (taken from your own tendons)  Patellar tendon  Hamstring tendon  Allografts (donated from someone else’s tendons)  Synthetic grafts (like silk) – less common

Typical ACL Reconstruction Surgery (contd) Incision made for an arthroscope (small camera) Incision where sterile fluid is pumped into knee joint Third incision for surgical instruments

Typical ACL Reconstruction Surgery (contd) Torn ACL is removed and area cleaned by motorized shaver Tunnels are drilled in tibia and femur for new graft  Surgeons use the footprints of the torn ACL roots for guidance Graft is pulled through tunnels and secured with bioabsorbable screws

Issues with ACL Reconstruction Surgery Drawbacks of using autografts:  Donor site pain and damage Drawbacks of using allografts:  Infections  Allergic Reactions  Disease Transmission In some surgeries, there has been poor placement of the graft  Results in less resistance to front-back motion

Stem Cell Therapy: Regenexx Process Dr. Centeno pioneered the Regenexx stem cell treatment Regenexx began this treatment in 2012 Stem Cell Therapy can treat partial tears and complete non-retracted tears Synovial sheath around ACL must be intact  This guides the injected stem cells to grow in the right area

Stem Cell Therapy: Regenexx Process Bone marrow aspirate is extracted from patient’s hip Stem cells are concentrated by centrifuging bone marrow several times Fluoroscopy and musculoskeletal ultrasound are used for visualization in order to accurately inject stem cells

Stem Cell Therapy: How it works Synovial sheath: one of the two membranes of the tendon sheath that covers the ACL Synovial sheath of the ACL must be intact In the case of an ACL tear, the sheath holds the torn fibers in the correct position Synovial sheath also facilitates the release of growth factors and cytokines This protective sheath acts as a guide that helps the injected stem cells work at the correct location Stem cells must be injected accurately in order to detect the sheath

Stem Cell Therapy: How it works (contd) The bone marrow contains mesenchymal stem cells (MSCs) MSCs are very good at differentiating into other cell types Cytokines help cells communicate The cytokines guide the MSCs to the zone of tissue injury The sheath guides the MSCs while they proliferate and regenerate

Success of Stem Cell Therapy Case studies show that 7/10 patients saw evidence of healing in their post-injection MRIs Stem Cell Therapy has been able to heal torn ACLs with up to 1 cm of separation Less painful than traditional ACL reconstruction surgery 6-12 weeks of recovery as opposed to 6-9 months of recovery from surgery

Success of Stem Cell Therapy (contd)

Developing Stem Cell Therapy Stem Cell Therapy is a new and growing treatment for injured ACLs

Bibliography issue_engineering/links/0c96052aa1e40355ac pdf issue_engineering/links/0c96052aa1e40355ac pdf cells-may-be-game-changer/ cells-may-be-game-changer/