Patient specific guides for total knee arthroplasty are ready for primetime

Table 7 Published level I studies with significant percentage of outliers of > 3˚ deviation between the patient specific matched guides and conventional intramedular and/or extramedular alignment method for hip-knee-ankle angle axis, frontal femoral component, frontal tibial component, flexion/extension of the femur component, lateral tibial component and axial rotation of the femur and/or tibia component controlled with postoperative X-ray (long-leg standing and/or lateral X-rays) and/or computed tomography

Outliers (%) > 3° deviation	PSG system	Modality	Conventional	Control	Sample size	Significant outliers (%)
			femur/tibia		(PSG/conventional)	(PSG/conventional)
Boonen et al[16]	Signature	MRI	Intra	X-ray	90/90	LFC (49/65)1
Chareancholvanich et al[17]	PSI	MRI	Intra/Extra	X-ray and CT	40/40	FFC (0/18)1
Chotanaphuti et al[18]	TruMatch	CT	Intra/Extra	X-ray and CT	40/40	NA
Hamilton et al[19]	TruMatch	Scout CT	Intra/Extra	X-ray	26/26	LTC (65/50)2
Ng et al[22] [Outliers (%) > 2° deviation]	PSI	MRI	Intra	CT	51/27	FTC (27/67)2, Femoral rotation (16/67)2, Tibial rotation (22/95)2
Pfitzner et al[24]	TruMatch	CT	Intra/Extra	X-ray and CT	(30/30)/30	HKA (30/7/43)2
	Visionaire	MRI + X-ray				FTC (13/3/23)1
						Femoral rotation (1/13 /50)1
Victor et al[25]	Signature	MRI, CT	Intra/Extra	X-ray and CT	(16/16/16/16)/64	FTC (15/3)1
	TruMatch	MRI + X-ray				LTC (21/3)2
	Visionaire	MRI				HKA (6/25/45/19)1, 3
	PSI					LFC (62/20/20/56)2, 3
Kotela et al[26]	Signature	CT	Intra/Extra	X-ray	49/46	FTC (39/20)1
Woolson et al[27]	TruMatch	CT	Intra/Extra	CT	22/26	LTC (32/8)1
Current study	Signature	MRI	Intra	X-ray	(15/13/14/15)/60	FFC (022)2
	TruMatch	CT				LFC (16/67)2
	Visionaire	MRI + X-ray				LTC (16/42)1
	PSI	MRI

¹Statistically significant different, P≤ 0.05;

²Statistically significant different, P≤ 0.005;

³Outliers > 3° deviation between the different PSG groups. NA: Not applicable for outliers; PSG: Patient specific matched guides; PSI: Patient-specific instrument; CT: Computed tomography; MRI: Magnetic resonance imaging; Intra: Intramedular; Extra: Extramedular; HKA: Hip-knee-ankle angle; FFC: Frontal femoral component; FTC: Frontal tibial component; LFC: Flexion/extension of the femur component; LTC: Lateral tibial component.