A novel, minimally-invasive technique of cartilage repair in the human knee using arthroscopic microfracture and injections of mesenchymal stem cells and hyaluronic acid--a prospective comparative study on safety and short-term efficacy

<p><b>INTRODUCTION</b>Most current cell-based cartilage repair techniques require some form of scaffolds and 2 separate surgical procedures. We propose a novel, scaffold-less technique of cartilage repair in the human knee that combines arthroscopic microfracture and outpatient intra-articular injections of autologous bone marrow-derived mesenchymal stem cells (MSCs) and hyaluronic acid (HA).</p><p><b>MATERIALS AND METHODS</b>Seventy matched (age, sex, lesion size) knees with symptomatic cartilage defects underwent cartilage repair with the proposed technique (n = 35) or an open technique (n = 35) in which the MSCs were implanted beneath a sutured periosteal patch over the defect. Prospective evaluation of both groups were performed using the International Cartilage Repair Society (ICRS) Cartilage Injury Evaluation Package, which included questions from the Short-Form (SF-36) Health Survey, International Knee Documentation Committee (IKDC) subjective knee evaluation form, Lysholm knee scale, and Tegner activity level scale. Postoperative magnetic resonance imaging (MRI) evaluation was also performed at 1 year for most patients.</p><p><b>RESULTS</b>There were no clinically significant adverse events reported through the course of our study. At the fi nal follow-up (mean = 24.5 months), there was significant improvement in mean IKDC, Lysholm, SF-36 physical component score and visual analogue pain scores in both treatment groups.</p><p><b>CONCLUSION</b>In the short term, the results of this novel technique are comparable to the open procedure with the added advantages of being minimally invasive and requiring only a single operation under general anaesthesia. Its safety has been validated and its efficacy is currently being evaluated in an ongoing randomised controlled trial.</p>

11th Yahya Cohen Memorial Lecture: An in vivo comparative study of the ability of derived mesenchymal stem cells in the treatment of partial growth arrest

Few in vivo studies had previously been attempted in reaffirming the in vitro data in current literature. This study evaluated the ability of mesenchymal stem cells (MSCs) isolated from bone marrow, periosteum and fat to treat partial growth arrest in immature New Zealand white (NZW) rabbits. A physeal arrest model in an immature rabbit was created. The bony bridge was excised 3 weeks later, and MSCs from various sources were transferred into the physeal defect of different rabbits. Group I consisted of bone marrow-derived MSCs, Group II: periosteumderived MSCs, Group III: fat-derived MSCs. Contra-lateral tibiae, without undergoing operation, served as self-control. The animals were subsequently sacrificed, with radiological and histological analyses performed. All MSCs demonstrated chondrogenic and osteogenic differentiation potentials in vitro. In correction of varus angulation groups I and II exhibited superior results when compared to group III (P <0.05). The length discrepancies between operated and normal tibiae in groups I, II and III were significantly corrected when compared to the control group (P <0.01). In conclusion, bone marrow and periosteum derived stem cells provided better correction of physeal arrest in rabbits. The source of MSCs itself could influence the success in the treatment of growth arrest.

Recurrent patellar dislocation: reappraising our approach to surgery

<p><b>INTRODUCTION</b>The management of recurrent traumatic patellar dislocation includes surgical realignment. There is no clear distinction whether proximal soft tissue or distal procedures produce superior results. However, distal realignment procedures are commonly associated with greater morbidity. We advocate a distal procedure only for cases which are more severe, such as the presence of patellar maltracking.</p><p><b>MATERIALS AND METHODS</b>Between January 2002 and June 2007, all patients who had a history of traumatic patellar dislocation with recurrent symptoms and failed conservative management underwent surgical realignment. Patients who had evidence of lateral patellar subluxation on computed tomography (CT) scan were offered a distal realignment procedure using the Elmslie-Trillat or Roux Goldthwaite procedure. All other patients underwent proximal soft tissue medial patellofemoral ligament (MPFL) reconstruction. Pre and postoperative functional International Knee Documentation Committee (IKDC), Lysholm and Tegner score assessments were performed for a minimum follow-up period of 6 months. The mean scores for each group were analysed using the Wilcoxon Matched-Pairs Signed-Ranks test and the Mann-Whitney U test was used to evaluate the difference between the groups.</p><p><b>RESULTS</b>A total of 23 patients underwent surgery for patellar realignment. Of whom, 14 patients had a distal realignment procedure while 9 patients had a proximal procedure of MPFL reconstruction. There was greater morbidity reported with distal realignment procedures. Pre and postoperative IKDC, Lysholm and Tegner scores showed significant improvement for both treatment arms. However, there was no significant difference between the improvement scores for both groups.</p><p><b>CONCLUSION</b>Patients with significant patellar maltracking following traumatic patellar dislocation would benefit from distal realignment using the Elmslie-Trillat or Roux Goldthwaite procedure. Otherwise, a proximal soft tissue procedure involving MPFL reconstruction would be adequate. A management algorithm is proposed for clinical use.</p>