Intraoperative physiological lateral laxity in extension and flexion for varus knees did not affect short-term clinical outcomes and patient satisfaction



Medial release during total knee arthroplasty (TKA) is used to correct ligament imbalance in knees with varus deformity. However, questions remain on whether residual ligament imbalance would be related to inferior clinical results. The purposes of the present study were to measure the intraoperative joint gap and to evaluate the effect of intraoperative soft tissue condition on the new Knee Society Score (KSS 2011) at 2-year follow-up, without the maneuver of additional medial release to correct the asymmetrical gap balance.


Varus–valgus gap angle and joint gap were measured using a tensor device without medial release for 100 knees with preoperative varus deformity. The knees were categorized according to the varus–valgus gap angle and the laxity. The preoperative and postoperative clinical outcomes using KSS 2011 were compared between the groups.


The average varus–valgus angles had a residual imbalance of 2.8° varus and 1.3° varus in extension and flexion, respectively. In comparison, according to varus–valgus joint gap angle and knee laxity in extension and flexion, no significant differences were found in postoperative range of motion and subscale of KSS 2011 among the groups.


Intraoperative asymmetrical joint gap and physiological laxity do not affect early clinical results after TKA.

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Total knee arthroplasty


Knee Society Score


Medial collateral ligament


Standard deviation




Femoral mechanical angle


Tibial mechanical angle


Western Ontario and McMaster Universities Arthritis Index


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Corresponding author

Correspondence to Shinichiro Nakamura.

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All authors declare that they have no conflict of interest.


One or more authors (SN and SM) received  research grant from Kyocera  outside the submitted work.

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The study design was approved by the institutional ethics review boards, and all procedures performed were in accordance with the ethical standards of the institutional research committee.

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Tanaka, Y., Nakamura, S., Kuriyama, S. et al. Intraoperative physiological lateral laxity in extension and flexion for varus knees did not affect short-term clinical outcomes and patient satisfaction. Knee Surg Sports Traumatol Arthrosc 28, 3888–3898 (2020).

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  • Total knee replacement
  • Total knee arthroplasty
  • Genu varum
  • Collateral ligaments
  • Joint laxity