Table 2.

Algorithm for symmetric and asymmetric flexion-extension gap balance issues where no mediolateral balance issues exist.

	Symmetric tightness/laxity in flexion-extension gaps	Asymmetric tightness/laxity in flexion-extension gaps
CAS data readout	Tight: FFD > 5° or <1 mm stress gaps in extension/flexion	Tight extension gap: FFD > 5° but appropriate flexion stress gap
	Loose: Hyperextension > 5° of native with >1 + mm stress gaps outside of the desired range	Tight flexion gap: appropriate extension but tight flexion stress gap
		Loose extension gap: hyperextension > 5° of native but appropriate flexion gap
		Loose flexion gap: appropriate extension but loose flexion gap
Clinical assessment	Tight: Unable to fully extend and poly squeaks and/or spits out in flexion	Tight extension gap: unable to fully extend but good flexion balance
	Loose: Hyperextending knee with excessive medial and lateral gaps/laxity	Tight flexion gap: can fully extend but poly squeaks and/or spits out in flexion
		Loose extension gap: hyperextending knee with excessive extension medial and lateral gaps but good flexion balance
		Loose flexion gap: can fully extend but flexion gaps are excessive
Response/Solution	Tight: Resect more of tibia	Tight extension gap: recut femur migrating proximally OR recut tibia more distally with less posterior slope
	Loose: Increase polyethylene thickness	Tight flexion gap: recut tibia with more posterior slope
		Loose extension gap: recut tibia with more posterior slope AND increase poly size
		Loose flexion gap: recut tibia with less posterior slope AND increase poly size