Authors’ Response:
As authors of the article “Comparison of 3 Knee-Specific Quality-of-Life Instruments for Patients With Meniscal Tears,”11 we intend with the following letter to respond to the criticisms raised by Ewa M. Roos in her letter to the editor. First, we thank Dr Roos for reading our article, for the letter containing constructive criticisms, and for stimulating an interesting scientific debate.
The aforementioned letter criticizes the method of evaluation utilized in our study—specifically, that in evaluating the results of the Knee injury and Osteoarthritis Outcome Score (KOOS) questionnaire, we performed comparative analyses based on the total scores and not, as recommended by Roos et al,10 on the subscores of the 5 subscales. To support this, Dr Roos cites her own, already published, studies.4,10
The purpose of our study was to compare the ability of 3 commonly used knee assessment tools to measure the impact of meniscal tears on knee function and quality of life: the WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index),1 the KOOS,10 and the WOMET (Western Ontario Meniscal Evaluation Tool).7 As the letter from Dr Roos mentions, to achieve this, a comparative analysis among the aforementioned questionnaires was undertaken. Given that the 3 analyzed questionnaires have very different constructions and structures, the best way to do this was, in our opinion, to directly compare the 3 tools. To achieve this, we calculated and compared their relative and total scores. Therefore, the results were based not only on the total scores of the KOOS, as stated by Dr Roos, but also on a “relative score.” This was a mean composite score, similar to KOOS5, that included all the subscores of the KOOS according to their specific weights. In this way, similar weighting from all subscales in the composite score was guaranteed.
We are aware that this will not completely satisfy the recommendations of Dr Roos. Nevertheless, as Dr Roos stated, this method of employing the KOOS “has been reported in many orthopaedic papers.”2,3,5,6,8,9,12–14 Moreover, taking into account the study’s purpose and setting, to report the results of the subscores of the KOOS would not have given any relevant information in those respects.
The criticism raised by Dr Roos is certainly relevant and represents a weakness of the aforementioned study, one that we are aware of. But we also see, in a reinterpretation of the study’s results based on the subscores, no additional benefit in terms of the study’s purpose.
We again thank Dr Roos for her interest in our study and for the constructive criticism.
Mirco Sgroi, MD
Semra Kocak
Heiko Reichel, MD
Thomas Kappe, MD
Ulm, Germany
Footnotes
The authors declared that they have no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.
References
- 1. Bellamy N, Buchanan WW, Goldsmith CH, Campbell J, Stitt LW. Validation study of WOMAC: a health status instrument for measuring clinically important patient relevant outcomes to antirheumatic drug therapy in patients with osteoarthritis of the hip or knee. J Rheumatol. 1988;15(12):1833–1840. [PubMed] [Google Scholar]
- 2. Buckwalter J, Bowman G, Albright J, Wolf B, Bollier M. Clinical outcomes of patellar chondral lesions treated with juvenile particulated cartilage allografts. Iowa Orthop J. 2014;34:44–49. [PMC free article] [PubMed] [Google Scholar]
- 3. Cartwright-Terry M, Yates J, Tan CK, Pengas IP, Banks JV, McNicholas MJ. Medium-term (5-year) comparison of the functional outcomes of combined anterior cruciate ligament and posterolateral corner reconstruction compared with isolated anterior cruciate ligament reconstruction. Arthroscopy. 2014;30(7):811–817. [DOI] [PubMed] [Google Scholar]
- 4. Collins NJ, Misra D, Felson DT, Crossley KM, Roos EM. Measures of knee function. Arthritis Care Res (Hoboken). 2011;63(suppl 11):S208–S228. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5. Hare KB, Lohmander LS, Christensen R, Roos EM. Arthroscopic partial meniscectomy in middle-aged patients with mild or no knee osteoarthritis: a protocol for a double-blind, randomized sham-controlled multi-center trial. BMC Musculoskelet Disord. 2013;14:71. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6. Hudson R, Richmond A, Sanchez B, et al. An alternative approach to the treatment of meniscal pathologies: a case series analysis of the mulligan concept “squeeze” technique. Int J Sports Phys Ther. 2016;11(4):564–574. [PMC free article] [PubMed] [Google Scholar]
- 7. Kirkley A, Griffin S, Whelan D. The development and validation of a quality of life-measurement tool for patients with meniscal pathology: the Western Ontario Meniscal Evaluation Tool (WOMET). Clin J Sport Med. 2007;17(5):349–356. [DOI] [PubMed] [Google Scholar]
- 8. Monk AP, Davies LJ, Hopewell S, Harris K, Beard DJ, Price AJ. Surgical versus conservative interventions for treating anterior cruciate ligament injuries. Cochrane Database Syst Rev. 2016;4:CD011166. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9. Oishi K, Tsuda E, Yamamoto Y, et al. The Knee injury and Osteoarthritis Outcome Score reflects the severity of knee osteoarthritis better than the revised Knee Society Score in a general Japanese population. Knee. 2016;23(1):35–42. [DOI] [PubMed] [Google Scholar]
- 10. Roos EM, Roos HP, Lohmander LS, Ekdahl C, Beynnon BD. Knee injury and Osteoarthritis Outcome Score (KOOS)—development of a self-administered outcome measure. J Orthop Sports Phys Ther. 1998;28(2):88–96. [DOI] [PubMed] [Google Scholar]
- 11. Sgroi M, Kocak S, Reichel H, Kappe T. Comparison of 3 knee-specific quality-of-life instruments for patients with meniscal tears. Orthop J Sports Med. 2018;6(1):2325967117750082 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12. Shaha JS, Cook JB, Rowles DJ, Bottoni CR, Shaha SH, Tokish JM. Return to an athletic lifestyle after osteochondral allograft transplantation of the knee. Am J Sports Med. 2013;41(9):2083–2089. [DOI] [PubMed] [Google Scholar]
- 13. Vundelinckx B, Vanlauwe J, Bellemans J. Long-term subjective, clinical, and radiographic outcome evaluation of meniscal allograft transplantation in the knee. Am J Sports Med. 2014;42(7):1592–1599. [DOI] [PubMed] [Google Scholar]
- 14. Zaffagnini S, Grassi A, Marcheggiani Muccioli GM, et al. Is sport activity possible after arthroscopic meniscal allograft transplantation? Midterm results in active patients. Am J Sports Med. 2016;44(3):625–632. [DOI] [PubMed] [Google Scholar]