We examined 52 patients with acute Achilles tendon rupture (ATR), 43 men and 9 women, with a median age of 43 (28–68) years after percutaneous Achilles tendon repair with early functional therapy. 11 patients were treated in a cast (C) and 41 had a specially designed shoed (S). The mean follow-up was 56 (36–95) months. Patients suffering from health problems, which could affect their gait and balance (e.g. OA, spinal stenosis,…), as well as patients suffering from complications postoperatively, were excluded from the study. The mean Hannover Achilles Tendon Score was 81 (50 – 95) points (C = 81, S = 81). Their calf muscle function studied three to eight years after treatment were found to have a significantly impaired dynamic muscle function of the calf muscles when tested in a specially constructed heel-raise test device. The Wilcoxon matched-pairs signed-ranks test showed a two-tailed P value of <
0,0001. The average calf size was 38 (31–46,5) cm on the uninjured side and 36 (32–44,5) cm on the injured side. Only two patients had an equal calf size. Comparing the uninjured and injured side the two-tailed P value was found to be extremely significant <
0,0001. The correlation between the maximum force and functional heel raise testing to the calf size on the injured side was weak with a Spearman correlation coefficient (r) = 0,33–38. There was no difference found between the patients treated in a cast and the patients treated in a shoe with percutaneous Achilles tendon repair and early functional therapy. The principle finding in the present study was that the impact of an ATR is of great importance for the functional outcome than the treatment that is given. The difference in flexion strength and endurance between the injured and the uninjured side remained even after a 56 months follow-up. Therefore, calf size and functional muscle testing is a good tool to test functional outcome after Achilles tendon rupture. However, there was only a weak correlation between the size of atrophy and the amount of force reduction.
A major challenge to be faced in order to introduce cell-based therapies for bone repair into wide-spread surgical practice is to translate a research-scale production model into a manufacturing design that is reproducible, clinically effective, and economically viable. One possible means by which to achieve this goal is via a bioreactor system capable of controlling, automating, and streamlining all of the individual phases of the bone-tissue engineering process. In a first step to meeting this challenge, in this work we aimed at developing and validating a closed bioreactor system for
the efficient seeding of cells into 3-dimensional scaffolds and the generation of osteoinductive constructs starting from human bone marrow-derived cells. Our patented bioreactor technology essentially consists of scaffolds arranged in a circular plate, which is moved in alternating directions by a linear drive unit through a cell suspension/culture medium, thus resulting in the perfusion of the cell suspension/culture medium directly through the pores of the scaffolds in alternate directions. The cultivation chamber is fully isolated from the external environment, with liquid/gas exchange achieved through aseptic interfaces. Human bone marrow nucleated cells from 3 donors were perfused through porous ceramic discs (8 mm diameter, 4 mm thick), resulting in adhesion of the osteoprogenitor cell fraction in the ceramic scaffolds. Efficiency of cell seeding was consistently greater than 80%. Cell seeded constructs were further cultivated under perfusion for a total of 20 days, resulting in the expansion of the osteoprogenitor cells directly within the scaffold pores and maintenance of greater than 90% cell viability. Ectopic implantation of the cultivated constructs yielded abundant and reproducible formation of bone tissue, distributed throughout the scaffold pores. The developed bioreactor provides a simple and efficient approach
to establish and maintain 3D cultures of cells into scaffolds under perfusion, and to generate osteoinductive grafts starting from minimally processed bone marrow aspirates and bypassing typical cell expansion in monolayers. Incorporating the bioreactor unit into a system for automated medium change and monitoring/control of culture parameters is likely to lead to the development of a closed system for the standardized production of autologous cell-based bone substitutes.
Radiological assessment revealed a complete osseoin-tegration in all 3 zones according to DeLee and Charnley in 98%. 1 cup with a continuous radiolucent line implanted after a acetabulum fracture had to be revised after a 13 year follow-up. 10 cups migrated either in the vertical or horizontal plane 2–5 mm without any progression after 2 years postoperatively. One cup had expansile osteolyses and had therefore to be revised after 13 years. With this exception there was no evidence of osteolyses in the periacetabular pelvic bone. Brooker III and IV ectopic ossifications was seen in decentration of the head of the stem as a sign of increased polyethylene-wear. Discussion: The excellent clinical and radiological results are supported by histologic investigations of 27 autopsy-specimens which show throughout a perfect osseoin-tegration with reinforcement of the osseous anchoring in the peripheral zones of the press-fit cup. We explain the wide absence of osteolyses with the disclaiming of a metal backing (preservation of elasticity and avoiding of stress shielding) and the disclaiming of using screws.