We are pleased to respond to each of the points raised by Mr. Satpathy in his recent letter to the editor.

The overall Merle d’Aubigne score was better in the refixation group, mainly due to less pain. In addition, the radiographically assessed increase in OA was higher in the resection group.

There is no evidence as yet that impingement by itself is painful. We agree that chondral and labral damage, which are secondary changes due to FAI, cause pain in these patients. As explicitly mentioned in the Results section of our paper, there was no statistical significant difference in the extent of labral or cartilaginous damage between both groups. The average values for depth of lesions as well as labral damage were precisely given.

As mentioned, there is substantial published evidence that the successful outcome of joint preserving procedures (for all joints) is a function of the condition of the joint cartilage(1-3).

Finally, we are surprised by the statement that "...there is no mention of the diameter of the lesion." We have used a clock face system for defining lesion sizes, which is explained in detail in the appendix section and the manuscript. We refer to page 931 of the paper where the labral defects as well as the chondral defects are denoted. The classification system we used to describe labral and cartilage lesions has been clearly given in the manuscript. As clearly stated in the paper, we have compared quite similar groups of lesions.

We hope we have addressed all issues raised.

Norman Espinosa, MD Michael Leunig, MD Reinhold Ganz, MD

References:

1. Beck, M,Leunig, M,Parvizi, J,Boutier, V,Wyss, D,Ganz, R. Anterior femoroacetabular impingement: part II. Midterm results of surgical treatment. Clin Orthop Relat Res. 2004; 418: 67-73.

2. Mardones, RM,Gonzalez, C,Chen, Q,Zobitz, M,Kaufman, KR,Trousdale, RT. Surgical treatment of femoroacetabular impingement: evaluation of the effect of the size of the resection. Surgical technique. J Bone Joint Surg Am. 2006; 88 Suppl 1 Pt 1: 84-91.

3. Mardones, RM,Gonzalez, C,Chen, Q,Zobitz, M,Kaufman, KR,Trousdale, RT. Surgical treatment of femoroacetabular impingement: evaluation of the effect of the size of the resection. J Bone Joint Surg Am. 2005; 87: 273- 9.

To The Editor:

I read with interest the article by Espinosa, et al, "Treatment of Femoro-Acetabular Impingement: Preliminary Results of Labral Refixation." I would note that the main difference in outcome of this study is improvement in pain score. Pain in these patients could be due to impingement,labral tear, or chondral lesions. Since impinging bone surfaces were debrided and labral tears were either excised or repaired, it will be important to quantify and classify the chondral lesions in these patients. The relationship between labral tear, associated chondral damage, and patient outcome has been correlated in studies by McCarthy, et al(1,2). It is very clear from those studies that there is substantial association between the size of the lesion and the final outcome of treatment.

In the study by Espinosa, et al,(3) there is no mention of the diameter of the lesion. They also doesn’t mention whether the lesion is partial thickness or full thickness. It is possible that the unsatisfactory outcome in group 1 where labral tears were excised could be due to the size and depth or the associated chondral defects rather than debridement of the labral tear.

References:

1. McCarthy J, Wardell S, Mason J, Bono J.Injuries to Acetabular Labrum: Classification, outcome and relationship to degenerative arthritis. Presented at the Annual meeting of American Academy of Orthopedic Surgeons, San Francisco 1997.

2. McCarthy J, Noble P, Aluisio F V, Schuck M, Wright J, Lee J.Anatomy, Pathologic Features, and Treatment of Acetabular Labral Tears.Clin Orthop Relat Res.2003;406;38-47.

3. Espinosa N, Rothenfluh D A, Beck M, Ganz R, Leunig M. Treatment of Femoro-Acetabular Impingement: Preliminary Results of Labral Refixation.J Bone Joint Surg Am.2006;88:925-935.