ORIGINAL PAPER Clinical and radiological long-term outcome after posterior cruciate ligament reconstruction and nonanatomical popliteus bypass Tom Adler & Niklaus F. Friederich & Felix Amsler & Werner Müller & Michael T. Hirschmann Received: 22 June 2014 /Accepted: 21 August 2014 /Published online: 17 September 2014 # SICOT aisbl 2014 Abstract Purpose The purpose of this study was to analyse the long- term outcome of patients treated for combined posterior cru- ciate ligament (PCL) and posterolateral corner injuries by combined PCL reconstruction and popliteus bypass according to Mueller or refixation of the popliteus tendon. Methods Sixteen patients treated by combined PCL recon- struction and popliteus bypass according to Mueller (n =7) or refixation of the popliteus tendon (n =9) were included. A mean follow-up of 24±three years was performed using the International Knee Documentation Committee (IKDC) 2000, Lysholm, Tegner and the Knee Injury and Osteoarthritis Outcome (KOOS) scores. Bilateral stress radiographs were performed. The degree of osteoarthritis was assessed using Kellgren Lawrence score. Pearson correlations of predictive factors for worse outcome were performed (p <0.05). Results Categorically, total IKDC 2000 was B (nearly nor- mal) in five (31 %), C (abnormal) in seven (44 %) and D (severely abnormal) in four (25 %) patients. Lysholm score was 68±22; KOOS symptom score was 40±13, KOOS pain 26±24, KOOS activity 18±18, KOOS sport 51±32 and KOOS LQ 44±26. Median Tegner score decreased from pre-injury 7 (range 4-10) to 4 (range 2-10) at follow-up. Kellgren Lawrence score showed minimal osteoarthritis in seven (44 %), moderate osteoarthritis in seven (44 %) and severe osteoarthritis in one (12 %) patient. Conclusions The challenging group of patients treated by PCL reconstruction and popliteus bypass according to Mueller et al. or popliteus refixation showed only moderate clinical and radiological long-term outcome without statistical difference, even if patient age at surgery and the long-term follow-up is acknowledged. Anatomical posterolateral corner reconstruction techniques should be preferred. Keywords Posterior cruciate ligament reconstruction . Popliteus bypass . Popliteus tendon refixation . Outcome Introduction Posterior cruciate ligament (PCL) injuries are frequently com- bined with posterolateral corner (PLC) injuries [1–3]. The incidence of acute PCL injuries varies between 3.4 % and 20 % [4], and the incidence of isolated PLC injuries is less frequent [2, 5–7]. Despite improved diagnostic possibilities, these injuries are still often missed [8–11]. When missed, these injuries in particular are known to lead to development of early osteoarthritis (OA), most likely in the medial tibiofemoral and patellofemoral joints [12]. This finding has been explained by constant overloading of the patellofemoral and medial tibiofemoral joints (reversed Maquet effect) [4, 13]. It is also known that missed lesions of peripheral struc- tures, such as the PLC, can cause instability and then lead to a subsequent early failure of PCL reconstruction [1, 14, 15]. This being emphasised, a variety of repair and reconstruction techniques, both nonanatomical and anatomical, have been reported over recent decades [14, 16–21]. Nonanatomical techniques, such as Clancy, Hughston/Jacobson and Mueller [14, 18, 21] were used initially. Increasingly, anatomical T. Adler : N. F. Friederich : W. Müller : M. T. Hirschmann (*) Department of Orthopaedic Surgery and Traumatology, Kantonsspital Baselland-Bruderholz, CH-4101 Bruderholz, Switzerland e-mail: michael.hirschmann@ksbl.ch M. T. Hirschmann e-mail: Michael_Hirschmann@web.de M. T. Hirschmann e-mail: Michael.Hirschmann@unibas.ch F. Amsler Amsler Consulting, Basel, Switzerland International Orthopaedics (SICOT) (2015) 39:131–136 DOI 10.1007/s00264-014-2515-7