Vol.:(0123456789) 1 3 European Journal of Orthopaedic Surgery & Traumatology https://doi.org/10.1007/s00590-020-02633-2 ORIGINAL ARTICLE Uniplanar versus biplanar monolateral external fxator knee arthrodesis after end‑stage failed infected total knee arthroplasty: a comparative study Pablo S. Corona 1,2,5  · Maria Jurado 1,5  · Ana Scott‑Tennent 3  · Rosa Fraile 2,4  · Luis Carrera 1,2,5  · Matías Vicente 1,2,5 Received: 9 December 2019 / Accepted: 22 January 2020 © Springer-Verlag France SAS, part of Springer Nature 2020 Abstract Background External fxator knee arthrodesis is a salvage procedure used primarily in cases of end-stage infected total knee replacement (iTKR). Stable fxation combined with bone-end compression is essential to achieve knee fusion, but providing sufcient stability can be challenging in the presence of severe bone loss. Our hypothesis is that using an external fxation biplanar confguration would bring about a fusion rate superior to that of a monolateral frame. Methods This study compares outcomes of biplanar external fxator knee fusion due to non-revisable iTKR with those of a historical cohort control study with patients managed with a monoplanar confguration. Primary endpoints were fusion rate, time to achieve bone fusion and infection eradication rate. Limb-length discrepancy, pain level, patient satisfaction and health-related quality of life were evaluated. Results A total of 29 knee fusion cases were included. In the biplanar group, infection was eradicated in 100% of the patients and fusion was achieved in all cases within an average of 5.24 months. In comparison, in the monolateral group, infection was eradicated in 86% of the cases and fusion was achieved in 81% of the patients after a mean of 10.3 months (p < 0.05). In both groups, postoperative pain was mild and patients expressed a high degree of satisfaction once fusion was achieved. Conclusions According to our data, external fxation knee fusion is a useful limb-salvage procedure in end-stage cases of knee PJI. We conclude that a biplanar confguration can halve the time required to achieve solid bone fusion in such a complex scenario. Keywords Knee arthrodesis · Periprosthetic joint infection · External fxator · Biplanar fxation Introduction In this era of total joint replacement, knee fusion is seldom indicated as a primary reconstructive procedure, though it is still a useful salvage tool in failed total knee replacement (TKR) cases. At present, the most common indication for knee fusion is a non-revisable failed TKR due primarily to infection [1]. Knee fusion, as a limb-salvage technique in end-stage infected total knee replacement (iTKR), is an alternative to amputation or resection arthroplasty [1–5]. It facilitates mobility and allows patients to maintain independ- ence, with a sensitive and stable extremity. The most efec- tive technique for arthrodesis in the presence of infection remains controversial [6]. The two most common techniques for knee fusion in this scenario are external fxation with various confgurations and internal fxation using intramed- ullary nails or plates [2, 7]. To date, no single technique has been proven superior in all situations; each has its relative Pablo S. Corona and Maria Jurado have contributed equally in producing this paper. * Matías Vicente matias.vicente@vhebron.net 1 Septic and Reconstructive Surgery Unit, Orthopaedic Surgery Department, Vall D’Hebron University Hospital, Universitat Autónoma de Barcelona, Pg. Vall d’Hebron 119-129, 08035 Barcelona, Spain 2 Septic and Reconstructive Surgery Unit, Orthopaedic Surgery Department, Vall D’Hebron University, Barcelona, Spain 3 Orthopaedic Surgery Department, Arnau de Vilanova University Hospital, Lleida, Spain 4 Surgical Nurse Team, Vall D’Hebron University Hospital, Universitat Autònoma de Barcelona, Barcelona, Spain 5 Musculoskeletal Tissue Engineering Group, Vall D’Hebron Research Institute, Universidad Autónoma de Barcelona (UAB), Barcelona, Spain