Greater postoperative relatively medial loose gap at 90° of flexion for varus knees improves patient-reported outcome measurements in anatomical bi-cruciate retaining total knee arthroplasty

• Published in: The knee Vol. 27; no. 5; pp. 1534 - 1541
• Main Authors: Kaneko, Takao, Mochizuki, Yuta, Hada, Masaru, Toyoda, Shinya, Takada, Kazutaka, Ikegami, Hiroyasu, Musha, Yoshiro
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.10.2020; Elsevier Limited
• Subjects: Aged; Anatomical bi-cruciate retaining total knee arthroplasty; Arthritis; Arthroplasty (knee); Arthroplasty, Replacement, Knee - methods; Coronal knee laxity; Correlation analysis; Female; Humans; Joint Instability - surgery; Joint replacement surgery; Joint surgery; Knee; Knee joint separation angle; Lateral joint gap; Ligaments; Medial; Osteoarthritis; Osteoarthritis, Knee - diagnosis; Osteoarthritis, Knee - physiopathology; Osteoarthritis, Knee - surgery; Patellofemoral Joint - diagnostic imaging; Patellofemoral Joint - physiopathology; Patellofemoral Joint - surgery; Patient Reported Outcome Measures; Patient-reported outcome measurement; Patients; Postoperative Period; Prostheses; Radiography; Range of Motion, Articular - physiology; United States > US; Japan; Anatomical bi-cruciate retaining total knee arthroplasty; Patient-reported outcome measurement; Knee joint separation angle; Medial; Coronal knee laxity; Lateral joint gap
• ISSN: 0968-0160; 1873-5800
• DOI: 10.1016/j.knee.2020.08.005

The purpose of the present study was to measure the intraoperative joint gap using tensor device and pre- and, postoperative joint stability at 0, 30 and 90° of flexion using stress radiography and to identify whether these factors influence patient-reported outcome measurement (PROM) in anatomical bi-cruciate retaining (BCR) knee arthroplasty (TKA). Fifty-three knees with preoperative varus osteoarthritis of the knee underwent anatomical BCR TKA with oblique three-degree angle femorotibial joint line. The intraoperative medial and lateral joint gap using a tensor device and gap difference (lateral minus medial; varus laxity) were also calculated. Postoperative joint stability was measured using stress radiographs. PROM was also evaluated at 1.5 years postoperatively. The effect of intraoperative and postoperative joint stabilities on PROMs were analyzed using Spearman's rank correlation analysis. Intraoperative greater difference between medial joint gap at 140° and 0° of flexion showed significant positive correlation with postoperative function of patellofemoral joint. Intraoperative varus laxity at extension improved postoperative symptoms in 2011 Knee Society Score (2011 KSS); greater postoperative lateral stability at 30 and 90° of flexion with the varus stress test was associated with the better patient expectation in 2011 KSS. Postoperative medial laxity at 90° of flexion with the valgus stress test positively correlated with the patient expectation and satisfaction in 2011 KSS. Surgeons should notice that the postoperative lateral stability and medial laxity at 90° of flexion improved PROM in anatomical BCR TKA.