Comparing Outcomes of Tumor Prosthesis Revision and Locking Plate Fixation in Supracondylar Femoral Periprosthetic Fractures

BACKGROUND: Periprosthetic fractures around a total knee replacement (TKR) can be complex and difficult to manage, requiring the surgical expertise of the trauma and arthroplasty surgeon. There are a number of treatment modalities available, each with their own merits and limitations. As data on tumor prosthesis revision in periprosthetic fractures is sparse, this study aims to evaluate the results of revision using a tumor prosthesis and compare them with those of fixation using a locking plate in periprosthetic fractures after TKR. METHODS: This is a retrospective study of 15 patients who underwent either tumor prosthesis revision (n = 7) or locking plate fixation (n = 8) for supracondylar femoral periprosthetic fractures in our hospital from 2009 and 2014. The mean follow-up time for these patients was 44 months. This study's main outcome measures were pain relief, return to premorbid ambulatory function, and complications. RESULTS: The revision and fixation groups saw five versus three patients achieve pain relief (71.4% vs. 37.5%, p = 0.315), and two versus four patients return to their premorbid ambulatory function (28.6% vs. 50%, p = 0.608) at the follow-up, respectively. The mean time to weight-bearing in the revision group and fixation group was 2.9 days and 18.9 weeks, respectively (p = 0.001). There were eight complications seen in the revision group with none requiring reoperation; there were five complications seen in the fixation group, and two required reoperation. CONCLUSIONS: The results of revision TKR using a tumor prosthesis were comparable to those of fixation using a locking plate in periprosthetic fractures after TKR. Tumor prosthesis revision may be considered as a viable alternative to locking plate fixation when indicated.

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.