Two previous publications on the Dutch WORC translation are available and not referred to in the current paper (De Witte et al., 2012; Wiertsema et al., 2013). Suzanne Wiertsema, VU University Medical Center 18 February 2014 Dear editor, Hereby we would like to react on the article: “The conceptually equivalent Dutch version of the Western Ontario Rotator Cuff Index (WORC)” by Ronald N. Wessel et al., which was recently published in BMC Musculoskeletal Disorders (1). The authors erroneously suggest they are the first to publish on the Dutch WORC, since there are two previous publications on the Dutch WORC translation. The first publication concerns an extensive validation study of the Dutch WORC by De Witte and colleagues in 2012 (2). The second publication concerns a translation and reproducibility study of the Dutch WORC by SH Wiertsema et al. published in 2013 (3). Around 2008 two Dutch groups (VU University Medical Center Amsterdam and Wessel’s group) started separately with the translation of the original WORC, both with permission of the developers of the original WORC. After Wessel had read our earlier publications, we agreed on one final Dutch version. We regret that this has not been mentioned in the Wessel-paper. We think it is important to mention that two earlier publications on the Dutch WORC are available. With kind regards, Suzanne H. Wiertsema, MSc, VU University Medical Center, Amsterdam Pieter Bas de Witte, MD, MSc, Leiden University Medical Center, Leiden Joost Dekker, PhD, professor, VU University Medical Center, Amsterdam References: 1) Wessel RN, Wolterbeeek N, Fermont AJ, van Mameren H, Sonneveld H, Griffin S, de Bie RA. The conceptually equivalent Dutch version of the Western Ontario Rotator Cuff Index (WORC). BMC Musculoskeletal Disorders 2013 14:362. 2) de Witte PB, Henseler JF, Nagels J, Vliet Vlieland TP, Nelissen RG.The Western Ontario rotator cuff index in rotator cuff disease patients: a comprehensive reliability and responsiveness validation study. Am J Sports Med. 2012 Jul;40(7):1611-9. Epub 2012 May 10. 3) Wiertsema SH, Rietberg MB, Hekman KM, Schothorst M, Steultjens MP, Dekker J. Reproducibility of the Dutch version of the Western Ontario rotator cuff Index. J Shoulder Elbow Surg. 2013 Feb;22(2):165-70. Epub 2012 Jun 27. Competing interests No competing interests.