Computerised tomography vs magnetic resonance imaging for modeling of patient-specific instrumentation in total knee arthroplasty

Table 1 Articles directly comparing computerised tomography and magnetic resonance imaging

Ref.	Article type	Sample size	Comparison of accuracy	Dimensional accuracy
Ensini et al[25]	Prospective randomized trial	25 CT PSI and 25 MRI PSI	Intra-operative navigation system and post-operative radiographic alignment	Comparable outcome
Cenni et al[9]	Prospective randomised trial	23 CT and 21 MRI PSI	Post-operative radiograph	Comparable outcome
Fritschy et al[26]	Prospective controlled trial	10 PSI patient, 10 standard TKAs (control)	Intra-operative navigation and post-operative long standing X-ray	Comparable outcome
Van den Broeck et al[27]	Human cadaveric study	9 cadaveric tibia	Comparison with bone dimensions using optical white-light scanner	Comparable outcome
White et al[28]	Animal study	10 ovine knees	Direct comparison with bone dimensions	CT > MRI
Rathnayaka et al[29]	Animal study	5 ovine limbs	Direct comparison with bone dimensions	Comparable outcome

TKA: Total knee arthroplasty; PSI: Patient-specific instrumentation; CT: Computerised tomography; MRI: Magnetic resonance imaging.

Table 2 Data assimilation of current patient-specific instrumentation literature

Ref.	Comparison	Type of study	System used	Imaging used	No. of patients	% outliers > 3%
Boonen et al[8]	PSI with disposable guides vs conventional intramedullary guides	Case control	Signature	MRI	40	29
Barrett et al[12]	PSI vs conventional - absolute mechanical axis measure	Prospective cohort study	Trumatch	CT	66	19
Bugbee et al[33]	PSI vs conventional	Retrospective cohort	Trumatch	CT	25	4
Chareancholvanich et al[13]	PSI vs conventional instrumentation	RCT	Zimmer	MRI	80	2.5
Koch et al[31]	PSI vs computer-navigated		My knee	CT	301	12.4
Chen et al[15]	PSI vs conventional TKA	Randomised control study	Zimmer PSI	MRI	30	31
Roh et al[32]	PSI vs conventional	RCT	Signature	CT	50	12

TKA: Total knee arthroplasty; PSI: Patient-specific instrumentation; CT: Computerised tomography; MRI: Magnetic resonance imaging; RCT: Randomised controlled trial.

Table 3 Currently available patient-specific instrumentation platforms (data adapted from Ast et al[6])

Manufacturer	Product	Imaging	Type of guide	Launched
Biomet	Signature-vanguard	CT or MRI	Pinning	MRI-2007 CT-2010
DePuy	Trumatch	CT	Cutting	2009
Smith and nephew	Visionaire	MRI	Pinning	2008
Wright medical	Prophecy	CT or MRI	Pinning	2009
Zimmer	PSI	MRI	Pinning	2009
Conformis	Conformis iTotal	CT	Cutting	2011
Medacta	My knee	CT	Cutting	2009

PSI: Patient-specific instrumentation; CT: Computerised tomography; MRI: Magnetic resonance imaging.