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Editorial Commentary: Ischiofemoral Impingement: Is This the “New” Femoroacetabular Impingement?
Editorial Commentary: Ischiofemoral Impingement: Is This the “New” Femoroacetabular Impingement?
Abstract: In a single-surgeon study of more than 1,000 hip operations, 30 patients were identified with possible ischiofemoral impingement (IFI). Only 17 of these 30 (56.6%) patients ultimately were diagnosed as having IFI on the basis of magnetic resonance imaging, injections, arthroscopy, and the 2 clinical tests described. The IFI test and the longstride walking test were both highly accurate for the purported diagnosis; however, the most accurate test that was not specifically prospectively studied was quadriceps muscle edema on magnetic resonance imaging, which was present only in otherwise confirmed cases of IFI and not seen with any other diagnosis.
See related article on page 1279
T
he article by Gómez-Hoyos et al.1 is a well-done study on a diagnosis, much like femoroacetabular impingement, which only recently has been “rediscovered.” The original paper describing ischiofemoral impingement (IFI) was published in 19772 on 3 patients after total hip arthroplasty. Since then, however, much of the literature regarding this diagnosis has been in the radiologic literature. These same authors previously published their results in a case series of the arthroscopic treatment of 5 patients.3 The purpose of this paper was to analyze the IFI and long-stride walking (LSW) tests in a larger clinical series. The authors stated the LSW test was more accurate than the IFI test but that using both tests was even more accurate. They appear to have established a very specific set of diagnostic criteria that others can use for additional study of this syndrome. As they appropriately point out, however, this was a single-surgeon study, and it is unclear whether author bias entered into the apparent high accuracy of the clinical tests, that is, was a positive test used to make the diagnosis or was the diagnosis made independently of the 2 clinical tests and then the accuracy of the clinical tests compared with the diagnosis that had been made without them? In my opinion, although this larger series is consistent with their first report, there are still too few reported cases (i.e., 22 total cases in the 2 reports) to make definitive recommendations on whether these tests, either in combination or alone, can be used to make the diagnosis of IFI. They also pointed out that Ó 2016 by the Arthroscopy Association of North America 0749-8063/16441/$36.00 http://dx.doi.org/10.1016/j.arthro.2016.05.023
quadriceps muscle edema was present on MRI in every patient with “proven” IFI, but they did not analyze how many patients had a positive IFI and LSW tests but did NOT have quadriceps edemadthat is, if quadriceps edema was present in every case of IFI, were there any “false positive” results with either clinical test in patients without quadriceps edema? As always, in my opinion, the physician should be cautious in using these tests to make the diagnosis of IFI, pending further study by independent surgeons with larger numbers to confirm the clinical utility and accuracy of these tests. As has become abundantly apparent in the use of alpha angles in the diagnosis of clinical femoroacetabular impingement or the various clinical tests for a shoulder SLAP lesion, we must be careful to avoid equating radiologic deviations or any single clinical test to diagnose clinically significant pathology that requires arthroscopic treatment. G. Klaud Miller, M.D. Associate Editor Emeritus
References 1. Gómez-Hoyos J, Martin RL, Schroeder R, Palmer IJ, Martin HD. Accuracy of two clinical tests for ischiofemoral impingement in patients with posterior hip pain and endoscopically confirmed diagnosis. Arthroscopy 2016;32: 1279-1284. 2. Johnson KA. Impingement on the lesser trochanter on the ischial ramus after total hip arthroplasty. Report of 3 cases. J Bone Joint Surg Am 1977;59:268-269. 3. Hatem MA, Palmer IJ, Martin HD. Diagnosis and two year outcomes of endoscopic treatment for ischiofemoral impingement. Arthroscopy 2015;31:239-246.
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 32, No 7 (July), 2016: p 1285
1285
Abstract: In a single-surgeon study of more than 1,000 hip operations, 30 patients were identified with possible ischiofemoral impingement (IFI). Only 17 of these 30 (56.6%) patients ultimately were diagnosed as having IFI on the basis of magnetic resonance imaging, injections, arthroscopy, and the 2 clinical tests described. The IFI test and the longstride walking test were both highly accurate for the purported diagnosis; however, the most accurate test that was not specifically prospectively studied was quadriceps muscle edema on magnetic resonance imaging, which was present only in otherwise confirmed cases of IFI and not seen with any other diagnosis.
See related article on page 1279
T
he article by Gómez-Hoyos et al.1 is a well-done study on a diagnosis, much like femoroacetabular impingement, which only recently has been “rediscovered.” The original paper describing ischiofemoral impingement (IFI) was published in 19772 on 3 patients after total hip arthroplasty. Since then, however, much of the literature regarding this diagnosis has been in the radiologic literature. These same authors previously published their results in a case series of the arthroscopic treatment of 5 patients.3 The purpose of this paper was to analyze the IFI and long-stride walking (LSW) tests in a larger clinical series. The authors stated the LSW test was more accurate than the IFI test but that using both tests was even more accurate. They appear to have established a very specific set of diagnostic criteria that others can use for additional study of this syndrome. As they appropriately point out, however, this was a single-surgeon study, and it is unclear whether author bias entered into the apparent high accuracy of the clinical tests, that is, was a positive test used to make the diagnosis or was the diagnosis made independently of the 2 clinical tests and then the accuracy of the clinical tests compared with the diagnosis that had been made without them? In my opinion, although this larger series is consistent with their first report, there are still too few reported cases (i.e., 22 total cases in the 2 reports) to make definitive recommendations on whether these tests, either in combination or alone, can be used to make the diagnosis of IFI. They also pointed out that Ó 2016 by the Arthroscopy Association of North America 0749-8063/16441/$36.00 http://dx.doi.org/10.1016/j.arthro.2016.05.023
quadriceps muscle edema was present on MRI in every patient with “proven” IFI, but they did not analyze how many patients had a positive IFI and LSW tests but did NOT have quadriceps edemadthat is, if quadriceps edema was present in every case of IFI, were there any “false positive” results with either clinical test in patients without quadriceps edema? As always, in my opinion, the physician should be cautious in using these tests to make the diagnosis of IFI, pending further study by independent surgeons with larger numbers to confirm the clinical utility and accuracy of these tests. As has become abundantly apparent in the use of alpha angles in the diagnosis of clinical femoroacetabular impingement or the various clinical tests for a shoulder SLAP lesion, we must be careful to avoid equating radiologic deviations or any single clinical test to diagnose clinically significant pathology that requires arthroscopic treatment. G. Klaud Miller, M.D. Associate Editor Emeritus
References 1. Gómez-Hoyos J, Martin RL, Schroeder R, Palmer IJ, Martin HD. Accuracy of two clinical tests for ischiofemoral impingement in patients with posterior hip pain and endoscopically confirmed diagnosis. Arthroscopy 2016;32: 1279-1284. 2. Johnson KA. Impingement on the lesser trochanter on the ischial ramus after total hip arthroplasty. Report of 3 cases. J Bone Joint Surg Am 1977;59:268-269. 3. Hatem MA, Palmer IJ, Martin HD. Diagnosis and two year outcomes of endoscopic treatment for ischiofemoral impingement. Arthroscopy 2015;31:239-246.
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 32, No 7 (July), 2016: p 1285
1285