Prosthetic inlay resurfacing for the treatment of focal, full thickness cartilage defects of the femoral condyle: A bridge between biologics and conventional arthroplasty

Purpose: Localized full thickness defects of the femoral condyle can be highly symptomatic. Treatment options for these lesions are numerous in young patients, however they become increasingly challenging in middle aged and older patients. In order to delay traditional joint replacement procedures and to provide a soft tissue and bone sparing alternative, this study assess a focal inlay resurfacing procedure. Methods: Between 2004 and 2008, a consecutive series of 27 patients were treated with the Arthrosurface HemiCAP® Focal Femoral Condyle Resurfacing Prosthesis and were assessed to study the clinical benefit of this procedure. Outcome measures included the KOOS, IKDC, HSS and WOMAC as well as physical and radiographic evaluation. Results: Nineteen patients met the inclusion/exclusion criteria, 18 were available for review at a median follow-up of 34 months (range 20-57). The median age was 49 years (range 43-78). 63% had early arthritis, 5. 2% localized osteonecrosis, and 31. 6% had a focal traumatic full thickness defect. The follow-up total WOMAC score averaged 90. 1 ± 9. 3, The KOOS showed very good to excellent scores in all domains and also when compared to age-matched normative data. Significant improvement was seen with the HSS Score. On IKDC examination, 83. 4% had normal or nearly normal results. Conclusion: Focal femoral condyle resurfacing demonstrated excellent results for pain and function in middle-aged, well selected patients with full thickness cartilage and osteochondral defects. Patient profiling and assessment of confounding factors, in particular mechanical joint alignment; meniscal function; and healthy opposing cartilage surfaces, are important for an individual treatment approach and successful outcomes. Level of evidence: IV. © 2011 Springer-Verlag

What is the best way to fix a polyurethane meniscal scaffold?: a biomechanical evaluation of different fixation modes

Ingrowth of meniscal tissue into a meniscal scaffold can be optimized by securely fixing the scaffold into the meniscal remnants. The purpose of this research was to test and compare commonly used suture types and suture materials to fix a meniscal scaffold. Forty fresh porcine menisci were used. All tests used the same polyurethane-based scaffold. The load to failure of horizontal, vertical and diagonal sutures with PDS 0 and with Ethibond 0, and diagonal sutures with Ultra Fast-Fix(A (R)) and Sequent(A (R)) to fix a meniscal scaffold were tested. Five tests were conducted for each configuration. All constructs failed in the scaffold at a mean pullout force of 50.6 N (SD 12.7). Inferior results were noted for vertical sutures (40.1 N, SD 6.3) compared to horizontal (49.8 N, SD 5.5, p = 0.0007) and diagonal (51.7 N, SD 15.6, p = 0.024) sutures and for Ethibond 0 (41.4 N, SD 6.2) compared to PDS 0 (51.3 N, SD 12.9, p = 0.001). When comparing the diagonal suture placements, only Ethibond 0 (42.9 N, SD 5.4) showed significantly inferior results compared to PDS 0 (60.1 N, SD 16.9, p = 0.03), Ultra Fast-Fix(A (R)) (60.1 N, SD 9.3, p = 0.004) and Sequent(A (R)) (65.8 N, SD 4.4, p < 0.0001). The most common failure mode when fixing a polyurethane-based meniscal scaffold is suture pull-through of the scaffold in the distraction mode. This happens at a rather low pullout force and might preclude the use of this scaffold clinically. Vertical sutures and Ethibond 0 multifilament braided sutures fail at lower forces, and the tested commercial devices show promising results

Proof of principle for transfusion of in vitro–generated red blood cells

In vitro RBC production from stem cells could represent an alternative to classic transfusion products. Until now the clinical feasibility of this concept has not been demonstrated. We addressed the question of the capacity of cultured RBCs (cRBCs) to survive in humans. By using a culture protocol permitting erythroid differentiation from peripheral CD34+ HSC, we generated a homogeneous population of cRBC functional in terms of their deformability, enzyme content, capacity of their hemoglobin to fix/release oxygen, and expression of blood group antigens. We then demonstrated in the nonobese diabetes/severe combined immunodeficiency mouse that cRBC encountered in vivo the conditions necessary for their complete maturation. These data provided the rationale for injecting into one human a homogeneous sample of 1010 cRBCs generated under good manufacturing practice conditions and labeled with 51Cr. The level of these cells in the circulation 26 days after injection was between 41% and 63%, which compares favorably with the reported half-life of 28 ± 2 days for native RBCs. Their survival in vivo testifies globally to their quality and functionality. These data establish the proof of principle for transfusion of in vitro–generated RBCs and path the way toward new developments in transfusion medicine. This study is registered at http://www.clinicaltrials.gov as NCT0929266