title: Centre of the posterior cruciate ligament and the sulcus between tubercle spines are reliable landmarks for tibial component placement.
abstract: OBJECTIVE
  The purpose of the present study was to determine whether the axes aligned with the sulcus between the tibial spines and the middle of the posterior cruciate ligament at the knee and with the tibialis anterior tendon at the ankle provide a neutral rotational and coronal alignment of the tibial component in total knee arthroplasty (TKA).
  
  
  METHODS
  In a cohort of 45 TKA patients, CT scans were taken to quantify coronal and rotational positioning of the components. All patients received a posterior stabilised total knee replacement with a fixed insert (PFC Sigma; DePuy Orthopaedics, Inc; Warsaw, IN, USA). The tibial guide was aligned with the sulcus between the tibial spines and the middle of the posterior cruciate ligament at the knee and with the tibialis anterior tendon at the ankle.
  
  
  RESULTS
  The average post-operative coronal mechanical alignment was 1° varus (range 4.5° varus-1.5° valgus; SD ±1.51). The average post-operative rotational deviation from the transepicondylar axes (TEA) was 0.78° of internal rotation (1.50° of internal rotation - 3.5° of external rotation) for the tibial component. The whole-extremity mechanical axis deviation was outside the tolerance range of 3° in 4 patients (8.9 %). Deviation of the tibial component rotational position relative to the TEA was 3° or less in 94.5 % of the patients.
  
  
  CONCLUSIONS
  When the tibial component is aligned using the axis drawn from the centre of the PCL to the sulcus between the tibial spines on the proximal tibia and to the tibialis anterior tendon at the ankle, good alignment will be achieved in both the coronal and axial planes.
  
  
  METHODS
  IV.
authors: Department of Orthopaedics and Traumatology, Bursa Şevket Yılmaz Research and Training Hospital, Yıldırım, 16330, Bursa, Turkey, sahinnamik@yahoo.com.
authors: Namık
authors: N
authors: Sahin
authors: Teoman
authors: T
authors: Atıcı
authors: Ünal
authors: Ü
authors: Kurtoğlu
authors: Ali
authors: A
authors: Turgut
authors: Güven
authors: G
authors: Ozkaya
authors: Yüksel
authors: Y
authors: Ozkan
mesh_terms: D000368:Aged; D059925:Anatomic Landmarks; D000843:Ankle Joint / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation / Q000379:methods*; D017760:Bone Malalignment / Q000000981:diagnostic imaging / Q000209:etiology / Q000517:prevention & control*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000601:surgery; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery*; D016119:Posterior Cruciate Ligament / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000517:prevention & control*; D011446:Prospective Studies; D012399:Rotation; D013710:Tendons / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D013977:Tibia / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome