Adherence of hip and knee arthroplasty studies to RSA standardization guidelines

Figures & data

Figure 1. PRISMA flow chart of study selection.

Table 1. List of the 13 guidelines and subcategories used to evaluate study adherence (adapted from Valstar et al. 2005)

Guideline number Subcategory		Guideline
1	A	Translation units in millimeters
	B	Rotation units in degrees
2	A	Accuracy presented
	B	Precision presented
	C	Measurement interval mentioned
	D	Window of tolerance mentioned
3		Type of calibration cage mentioned
4		Fixed or portable X-ray sources used
5	A	Subject positioning described
	B	Orientation of global coordinate system presented
6	A	Method of image acquisition stated
	B	Scanner or system details mentioned
7	A	Software name mentioned
	B	Software version mentioned
8	A	Marker size mentioned
	B	Marker size validated (or manufacturer mentioned)
9		RSA method mentioned (marker, model, etc.)
10	A	Cutoff level for condition number noted
	B	Cutoff level for mean error of rigid-body fitting noted
11	A	Rigid-body fixed coordinate frames defined
	B	Angular rotation sequence mentioned if relevant
12	A	Precision determined using double examinations
	B	Double examinations of all patients performed
13	A	All 6 degrees of freedom reported
	B	Point or segment motion used
	C	Point(s) used to measure translation indicated

Figure 2. The annual numbers of hip and knee arthroplasty RSA studies published from 2000 to 2011 that met the inclusion criteria (bars) and the proportion of studies with high adherence (line). The RSA guidelines where published at the end of 2005.

Figure 3. Adherence of studies published after the guidelines to each of the 13 individual guideline items. The levels of adherence are presented in green (full adherence), yellow (partial adherence), and red (no adherence). Guidelines are presented left to right from highest to lowest adherence. The guideline number is given in parentheses.

Table 2. Adherence of studies published during 2006–2011 to the RSA guidelines according to region of publication

	Total no. of studies	Number (%) of studies with high adherence ^a
Nordic countries ^b	55	29 (53)
Rest of Europe ^c	21	8 (38)
USA/Canada	9	3 (33)
Australia	7	3 (43)

^a Partial or full adherence to at least 10 of 13 RSA guidelines.

^b Denmark, Finland, Norway, and Sweden.

^c Germany, Italy, the Netherlands, UK.

Table 3. Adherence of studies published during 2006–2011 to the RSA guidelines according to journal

	Total no. of studies	No. of studies with high adherence ^a
Acta Orthopaedica	23	9
Clinical Orthopaedics and
Related Research	18	12
Journal of Arthroplasty	13	4
Journal of Bone and Joint
Surgery (British Volume)	12	3
International Orthopaedics	6	2
The Knee	4	2
Other ^b	16	11

^a Partial or full adherence to at least 10 of 13 RSA guidelines.

^b 11 journals with 2 publications or less that met the inclusion criteria during the study period.

Table 4. Suggested presentation of standardized output for a clinical RSA study

Items relevant to the Materials and Methods section of the study

Time period of patient recruitment

Positioning of subject and calibration cage

Orientation of the global coordinate system (consider a diagram)

Rigid body fixed coordinate frames defined

RSA method (marker-based, geometrical or model-based) and version of RSA software

Units used for translation millimeters and the units for rotations degrees

Measurement interval

The points used to measure translation indicated (consider an x-ray or diagram)

Translations and angular rotations with all six degrees of freedom if applicable

Clinical precision

Number of patients for whom RSA was not successful

Items to be mentioned in an appendix of the study

Accuracy of the arrangement (if phantom studies have been performed)

Size and manufacturer of RSA markers

Type and manufacturer of calibration cage

Fixed or portable x-ray sources and manufacturer

Radiographic exposure settings (kV and mAs)

Window of tolerance for both postoperative and follow-up RSA examinations (days/weeks)

Method of image acquisition and scanner or system details as well as image resolution

Number of patients for whom double examinations were performed

Cut-off level for CN and ME

Formula used to calculate confidence interval for precision

Angular rotation sequence defined (if relevant)

Valstar ER, Gill R, Ryd L, Flivik G, Börlin N, Kärrholm J. Guidelines for standardization of radiostereometry (RSA) of implants. Acta Orthop 2005; 76 (4): 563-72.

 PubMed Web of Science ®Google Scholar