Accuracy of a portable accelerometer-based navigation system for cup placement and intraoperative leg length measurement in total hip arthroplasty: a cross-sectional study

Table 3 The accuracies of the leg length measurements in the present and previous studies

	Method	Correlation between intraoperative and radiographic leg length changes. The Pearson correlation coefficient and P value	Accuracy of leg length measurement (mm)
Ranawat [36]	Caliper	0.82, significant*	–
Rice [38]	Caliper	0.275, P > 0.05	3.2 ± 8.0 (absolute value)
Enke [39]	Caliper	0.259, not significant	–
Renkawitz [13, 14, 17]	Imageless navigation (cadaver study)	0.83, P < 0.001*	0.74^a
	Imageless navigation (cadaver study)	0.92, P < 0.001*	0.50^a
	Imageless navigation	0.80, P < 0.001*	0.35^a
Kitada [8]	CT-based navigation	–	1.3 ± 4.1^a
Ogawa [40]	CT-based navigation	0.88, P < 0.001*	2.4 ± 1.7 (absolute value)
Ogawa [40]	Caliper	0.89, P < 0.001*	2.1 ± 1.6 (absolute value)
Ecker, Murphy and Ecker [1, 12]	CT-based navigation	–	−0.5 ± 1.7^a
This study	Portable navigation	0.80, P = 0.000*	0.8 ± 3.4^a
This study			2.3 ± 2.6 (absolute value)

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