reversed gap technique for an individualized positioning of a total knee arthroplasty

• Applicants: Professor Dr. Georg Matziolis; Dr. Eric Röhner
• Subject Area: Orthopaedics, Traumatology, Reconstructive Surgery
• Term: from 2017 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 394628756

In contrast to total hip arthroplasty (THA) the clinical results after total knee arthroplasty (TKA) are up to know unsatistfactory. The rate of unsatisfied patients is constant over the last decades 20 % - 25 % (1,2). In Germay 130.000 TKA are performed every year (3), so that over 30.000 patients are produced every year staying unsatisfied with the operation result. It is evident, that different causes are responsible for that (4,5). The fact, that after THA only 5 % of the patients are unsatisfied as well as the facts, that indication, preoperative and postoperative treatment after THA and TKA are comparable, point out, that the causes are probably produced during the operation (implant choice, alignment, operative technique). No artificial joint can reproduce the complex knee kinematic reproducibly (6-7). This corresponds with surrogate parameters like a pathologic gait (8) as well as in insufficient forgotten knee scores (9,10). Even the implant geometry of concurring design philosophies (e.g. single-radius vs. J-curve) differ in the range of single millimeters. The variability of intraoperative implant positioning is in the same range, so that suboptimal alignment limits the outcome of modern implant designs. The optimal alignment is up to now unclear and results from the surgeons preferred operative technique.Our workgroup has developed a new operative technique and evaluated it in a pilot study. Based on the encouraging results the clinical outcome of this reversed gap technique shall be prospectively randomized evaluated using the established gap technique as control.

• DFG Programme: Research Grants