TY  - JOUR
A1  - Hammerich, Kristoff
A1  - Pollack, Jens
A1  - Hasse, Alexander F.
A1  - El-Saman, André
A1  - Huber, René
A1  - Rupp, Markus
A1  - Alt, Volker
A1  - Kinne, Raimund W.
A1  - Mika, Jörg
T1  - The inverse spacer - a novel, safe, and cost-effective approach in routine procedures for revision knee arthroplasty
T2  - Journal of Clinical Medicine
N2  - Background: A major disadvantage of current spacers for two-stage revision total knee arthroplasty (R-TKA) is the risk of (sub-) luxation during mobilization in the prosthesis-free interval, limiting their clinical success with detrimental consequences for the patient. The present study introduces a novel inverse spacer, which prevents major complications, such as spacer (sub-) luxations and/or fractures of spacer or bone. Methods: The hand-made inverse spacer consisted of convex tibial and concave femoral components of polymethylmethacrylate bone cement and was intra-operatively molded under maximum longitudinal tension in 5° flexion and 5° valgus position. Both components were equipped with a stem for rotational stability. This spacer was implanted during an R-TKA in 110 knees with diagnosed or suspected periprosthetic infection. Postoperative therapy included a straight leg brace and physiotherapist-guided, crutch-supported mobilization with full sole contact. X-rays were taken before and after prosthesis removal and re-implantation. Results: None of the patients experienced (sub-) luxations/fractures of the spacer, periprosthetic fractures, or soft tissue compromise requiring reoperation. All patients were successfully re-implanted after a prosthesis-free interval of 8 weeks, except for three patients requiring an early exchange of the spacer due to persisting infection. In these cases, the prosthetic-free interval was prolonged for one week. Conclusion: The inverse spacer in conjunction with our routine procedure is a safe and cost-effective alternative to other articulating or static spacers, and allows crutch-supported sole contact mobilization without major post-operative complications. Maximum longitudinal intra-operative tension in 5° flexion and 5° valgus position appears crucial for the success of surgery.
KW  - inverse spacer
KW  - intraoperatively molded
KW  - cost-effective
KW  - (sub-) luxation
KW  - dislocation
KW  - revision knee arthroplasty
Y1  - 2021
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/62151
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-621511
SN  - 2077-0383
N1  - This research received no external funding. We acknowledge publication support by the German Research Foundation (DFG) and the Open Access Publication Fund of Hannover Medical School (MHH).
VL  - 10
IS  - 5, art. 971
SP  - 1
EP  - 9
PB  - MDPI
CY  - Basel
ER  -