Intraoperative soft tissue balance using novel medial preserving gap technique in posterior-stabilized total knee arthroplasty: comparison to measured resection technique

• Published in: Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA Vol. 26; no. 11; pp. 3474 - 3481
• Main Authors: Nagai, Kanto, Muratsu, Hirotsugu, Kanda, Yutaro, Tsubosaka, Masanori, Kamenaga, Tomoyuki, Miya, Hidetoshi, Matsushita, Takehiko, Niikura, Takahiro, Kuroda, Ryosuke, Matsumoto, Tomoyuki
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-11-2018; Springer Nature B.V
• Subjects: Aged; Arthroplasty (knee); Arthroplasty, Replacement, Knee - methods; Biocompatibility; Biomechanical Phenomena; Biomedical materials; Case-Control Studies; Female; Femoral components; Femur; Humans; Joint surgery; Knee; Knee Joint - surgery; Lateral stability; Male; Mathematical analysis; Medicine; Medicine & Public Health; Orthopedics; Osteoarthritis; Osteoarthritis, Knee - surgery; Range of Motion, Articular - physiology; Surgical implants; Posterior-stabilized; Offset-type tensor; Gap balancing technique; Total knee arthroplasty; Medial preserving gap technique; Measured resection technique; Osteoarthritis; Soft tissue balance
• ISSN: 0942-2056; 1433-7347
• DOI: 10.1007/s00167-018-4945-z

Purpose
To investigate intraoperative soft tissue balance with femoral component trial in place using a novel medial preserving gap technique, focusing on medial compartment stability and allowing lateral physiological laxity, with compared with using a measured resection technique in posterior-stabilized (PS) total knee arthroplasty (TKA).
Methods
Primary PS TKA, using either medial preserving gap technique (
n
 = 127) or measured resection technique (
n
 = 148), was performed in 275 subjects with varus knee osteoarthritis. Intraoperative soft tissue balance with femoral component in place was assessed using Offset Repo-Tensor with 40 lbs. of joint distraction force throughout the range of motion, and medial and lateral compartment gaps (mm) were calculated. Medial and lateral joint gap changes (mm) were calculated by subtracting the medial/lateral compartment gap at 0° from the medial/lateral compartment gap at each knee flexion angle, respectively.
Results
Medial and lateral joint gap changes in medial preserving gap technique were significantly smaller than measured resection technique respectively (mean difference between two procedures: medial; 0.9 ± 0.2 mm, lateral; 1.0 ± 0.3 mm). Medial and lateral joint gaps were significantly changed during knee flexion in measured resection technique, whereas medial and lateral joint gaps were not significantly changed during mid-to-deep knee flexion (30°–90° in medial, 30°–120° in lateral) in medial preserving gap technique.
Conclusions
Medial preserving gap technique provided more consistent intraoperative soft tissue balance during knee flexion than the measured resection technique, suggesting that this novel technique can be utilized to obtain a more stable joint gap in PS TKA.
Level of evidence
III.