title: High Tibial Osteotomy in Combination With Chondrogenesis After Stem Cell Therapy: A Histologic Report of 8 Cases.
abstract: OBJECTIVE
  To histologically evaluate the quality of articular cartilage regeneration from the medial compartment after arthroscopic subchondral drilling followed by postoperative intra-articular injections of autologous peripheral blood stem cells (PBSCs) and hyaluronic acid with concomitant medial open-wedge high tibial osteotomy (HTO) in patients with varus deformity of the knee joint.
  
  
  METHODS
  Eight patients with varus deformity of the knee joint underwent arthroscopic subchondral drilling of International Cartilage Repair Society (ICRS) grade 4 bone-on-bone lesions of the medial compartment with concomitant HTO. These patients were part of a larger pilot study in which 18 patients underwent the same procedure. PBSCs were harvested and cryopreserved preoperatively. At 1 week after surgery, 8 mL of PBSCs was mixed with 2 mL of hyaluronic acid and injected intra-articularly into the knee joint; this was repeated once a week for 5 consecutive weeks. Three additional intra-articular injections were administered weekly at intervals of 6, 12, and 18 months postoperatively. Informed consent was obtained at the time of hardware removal for opportunistic second-look arthroscopy and chondral biopsy. Biopsy specimens were stained with H&E, safranin O, and immunohistochemical staining for type I and II collagen. Specimens were graded using the 14 components of the ICRS Visual Assessment Scale II, and a total score was obtained.
  
  
  RESULTS
  Second-look arthroscopy showed satisfactory healing of the regenerated cartilage. Histologic analysis showed significant amounts of proteoglycan and type II collagen. The total ICRS Visual Assessment Scale II histologic scores comparing the regenerated articular cartilage (mean, 1,274) with normal articular cartilage (mean, 1,340) indicated that the repair cartilage score approached 95% of the normal articular cartilage score. There were no infections, delayed unions, or nonunions.
  
  
  CONCLUSIONS
  Chondrogenesis with stem cells in combination with medial open-wedge HTO for varus deformity correction of the knee joint regenerates cartilage that closely resembles the native articular cartilage.
  
  
  METHODS
  Level IV, therapeutic case series.
authors.affiliation: Kuala Lumpur Sports Medicine Centre, Kuala Lumpur, Malaysia. Electronic address: sportsclinic@hotmail.com.
authors.forename: Khay-Yong
authors.initials: KY
authors.lastname: Saw
authors.affiliation: Andrews Research and Education Institute, Gulf Breeze, Florida, U.S.A.
authors.forename: Adam
authors.initials: A
authors.lastname: Anz
authors.affiliation: Kuala Lumpur Sports Medicine Centre, Kuala Lumpur, Malaysia.
authors.forename: Caroline Siew-Yoke
authors.initials: CS
authors.lastname: Jee
authors.affiliation: Kuala Lumpur Sports Medicine Centre, Kuala Lumpur, Malaysia.
authors.forename: Reza Ching-Soong
authors.initials: RC
authors.lastname: Ng
authors.affiliation: Department of Pathology, Universiti Putra Malaysia, Serdang, Malaysia.
authors.forename: Norhafizah
authors.initials: N
authors.lastname: Mohtarrudin
authors.affiliation: Genomed, Klang, Malaysia.
authors.forename: Kunaseegaran
authors.initials: K
authors.lastname: Ragavanaidu
mesh_terms: D054544:Arthroplasty, Subchondral; D001182:Arthroscopy / Q000379:methods; D002358:Cartilage, Articular / Q000293:injuries / Q000502:physiology*; D020219:Chondrogenesis; D005260:Female; D006801:Humans; D006820:Hyaluronic Acid / Q000008:administration & dosage; D007270:Injections, Intra-Articular; D007719:Knee Joint / Q000601:surgery; D008297:Male; D008875:Middle Aged; D010027:Osteotomy / Q000379:methods*; D010865:Pilot Projects; D012038:Regeneration; D012189:Retrospective Studies; D024162:Second-Look Surgery / Q000379:methods; D033581:Stem Cell Transplantation; D055675:Viscosupplements / Q000008:administration & dosage; D014945:Wound Healing
chemical_list: D055675:Viscosupplements; D006820:Hyaluronic Acid