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Reply to the letter by Mark Laslett on the review entitled: “Provocative sacroiliac joint maneuvers and sacroiliac joint block are unreliable for diagnosing sacroiliac joint pain”
Correspondences / Joint Bone Spine 74 (2007) 306e308
Mark Laslett* Peter van der Wurff Evert Buijs Charles N. Aprill Moorhouse Medical Centre, PhysioSouth, Level 2, 3 Pilgrim Place, Christchurch, Canterbury, New Zealand *Corresponding author. Tel.: þ64 3 385 5446; fax: þ64 3 377 0614. E-mail address: [email protected] (M. Laslett) 19 August 2006 Available online 7 March 2007 DOI of original article: 10.1016/j.jbspin.2004.08.003 1297-319X/$ - see front matter Ó 2007 Elsevier Masson SAS. All rights reserved. doi:10.1016/j.jbspin.2006.11.006
Reply to the letter by Mark Laslett on the review entitled: ‘‘Provocative sacroiliac joint maneuvers and sacroiliac joint block are unreliable for diagnosing sacroiliac joint pain’’ Keywords: Sacroiliac joint; Diagnosis; Reference standard; Controlled blocks; Clinical tests
We thank Dr Laslett et al. for their enthusiastic comments, and do apologize for not including their recent works in our former review (which had been submitted more than two years ago) [1]. Our main goal was to stress the possibility of false positive results of sacroiliac blocks, related either to placebo/Hawthorne effects and/or communications between sacroiliac joints and surrounding tissues (including ligaments and nerves) [2]. In our opinion, this should still preclude their use as a gold standard (although they might deserve a ‘silver standard’ label). Indeed, too much confidence in those tests/blocks might lead to circular reasoning, and unnecessary fusion of sacroiliac joints for many patients with chronic back or buttock pain. In this respect, it should be kept in mind that the results of those fusions can be rather poor, even in patients with highly probable sacroiliac pain [3]. In other words, we think that the specificity of either clinical tests or a single diagnosis block should be even better than 0.80, to be considered reliable enough to prompt sacroiliac surgery and discard other explanations for chronic back pain. Although they recognized in their recent works that perfect gold standards did not exist for the diagnosis of discogenic, facetogenic pain, or pain arising from the SIJ [4], Laslett et al. seemingly did not check whether a leakage of the contrast medium out of the sacroiliac joint had occurred before considering their (single) sacroiliac block as positive [5,6]. Hence, it cannot be ruled out that some pain ascribed to the sacroiliac joint indeed arose from neighbouring tissues. The same holds true for the report by van der Wurff et al. [7], who performed two blocks (with a short and a long lasting anaesthetic) using 3 ml (1 cm3 of contrast medium and 2 cm3 of anaesthetic fluid), and did observe some leakages, even leading to temporary
307
sciatic palsy in five patients. We quite agree with the useful advice of Dr Laslett et al. to use no more than 0.5 cm3 of contrast media and 1 cm3 of anaesthetic fluid, although it should be checked whether when using such volume no leakage can still occur, and whether the relief of pain is equal to what has been observed with larger volumes [7]. The studies by Laslett et al. [4e6] have high scientific content, and are probably the most valuable breakthroughs on this frustrating topic. However, they would be even more convincing if it can be definitively proven that the phenomenon of centralization is so specific for pain of disc origin that no other diagnosis should be considered [8]. Indeed, the increased specificity of sacroiliac tests observed by Laslett et al. (up to 0.87) [5,6], compared with previous papers, has been favoured by the elimination from the control group of patients with a centralization phenomenon. This is an important point, as pain arising from the discs is probably the most frequent differential diagnosis to consider in patients with back/buttock pain. Similarly, the specificity of a test for diagnosing back/buttock pain should ideally be calculated using a control group representative of the whole population of patients with back/buttock pain. In another nice study by Laslett et al. [4] the authors observed in a sample of 216 chronic lumbar pain patients that only 67% could receive a patho-anatomic diagnosis based on available reference standards, 10% had more than one tissue origin of pain identified, and only 51% were given the same diagnosis by two physiotherapists. This underlines the difficulty of conducting such studies without rather strong selection bias of the control group, as also stressed by van der Wurff et al. in a previous response [9]. The second explanation for the discrepancies between recent results [5e7] and those summarized in our review [1], might be the threshold of pain relief required to consider a sacroiliac block as positive. For instance van der Wurff et al. [7] considered that a 50% reduction of pain was enough (compared with the threshold of 75% selected by Maigne et al. [10], and 80% by Laslett et al. [5]), which did offer a very clear split of patients between two groups of 27 responders and 33 nonresponders [7]. However, this should lead to the conclusion that 45% of chronic low-back pain originates from the sacroiliac joint stricto sensu, which appears rather improbable, and might cast doubt on the validity of the control group in this study too [7]. Indeed, figures from past works using a double-block paradigm, ranged from 10% to 19% [11]. To reconcile those observations, we proposed that many patients relieved by a sacroiliac block could indeed suffer from sacroiliac lato sensu, i.e. from surrounding ligaments, including ilio-lumbar ligaments, and suggested that explanations other than the sacroiliac joint itself should still be considered, even when several ‘sacroiliac’ provocation tests (which also stress lumbar structures) are positive [1]. This would be in agreement with the improvement induced in 13/18 patients with pain arising from the sacroiliac joint, by blocks of the L4e5 dorsal rami and S1e3 lateral branches [12] which innervate the ligaments surrounding the sacroiliac joint probably as much as the sacroiliac joint stricto sensu. Hence, we would quite agree with Dr Laslett that clinical tests (and perhaps
308
Correspondences / Joint Bone Spine 74 (2007) 306e308
sacroiliac blocks) should be more specific for ‘sacroiliac syndrome’ than for ‘sacroiliac joint pain’. References [1] Berthelot JM, Labat JJ, Le Goff B, Gouin F, Maugars Y. Provocative sacroiliac joint maneuvers and sacroiliac joint block are unreliable for diagnosing sacroiliac joint pain. Joint Bone Spine 2006;73:17e23. [2] Fortin JD, Washington WJ, Falco FJ. Three pathways between the sacroiliac joint and neural structures. AJNR Am J Neuroradiol 1999; 20:1388e9. [3] Schutz U, Grob D. Poor outcome following bilateral sacroiliac joint fusion for degenerative sacroiliac joint syndrome. Acta Orthop Belg 2006;72:296e308. [4] Laslett M, McDonald B, Tropp H, Aprill CN, Oberg B. Agreement between diagnoses reached by clinical examination and available reference standards: a prospective study of 216 patients with lumbopelvic pain. BMC Musculoskeletal Disord 2005;6:28. [5] Laslett M, Young SB, Aprill CN, McDonald B. Diagnosing painful sacroiliac joints: a validity study of a McKenzie evaluation and sacroiliac provocation tests. Aust J Physiother 2003;49:89e97. [6] Laslett M, Aprill CN, McDonald B. Provocation sacroiliac joint tests have validity in the diagnosis of sacroiliac joint pain. Arch Phys Med Rehab 2006;6:874e5. [7] Laslett M, Oberg B, Aprill CN, McDonald B. Centralization as a predictor of provocation discography results in chronic low back pain, and the influence of disability and distress on diagnostic power. Spine J 2005;5:370e80. [8] Van der Wurff P, Buijs EJ, Groen GJ. A multitest regiment of pain provocation tests as an aid to reduce unnecessary minimally invasive sacroiliac joint procedures. Arch Phys Med Rehabil 2006;87:10e4.
[9] van der Wurff P, Buijs EJ, Gerbrand J, Groen GJ. The authors respond. Arch Phys Med Rehabil 2006;87:874e5. [10] Maigne JY, Planchon CA. Sacroiliac joint pain after lumbar fusion. A study with anesthetic blocks. Eur Spine J 2006;15:8e15. [11] McKenzie-Brown AM, Shah RV, Sehgal N, Everett CR. A systematic review of sacroiliac joint interventions. Pain Physician 2005;8: 115e25. [12] Cohen SP, Abdi S. Lateral branch blocks as a treatment for sacroiliac joint pain: a pilot study. Reg Anesth Pain Med 2003;28:113e9.
Jean-Marie Berthelot* Hoˆtel-Dieu-CHU Nantes, 1, Place Alexis Ricordeau, Nantes Cedex 01, France *Correspondence author. Rheumatology Unit, Nantes University Hospital (CHU Nantes), 44093, Nantes, France. Tel.: þ33 02 40 08 48 22/25/01; fax: þ33 02 40 08 48 30. E-mail address: [email protected] 19 September 2006 Available online 5 March 2007 DOI of original article: 10.1016/j.jbspin.2004.08.003 1297-319X/$ - see front matter Ó 2007 Elsevier Masson SAS. All rights reserved. doi:10.1016/j.jbspin.2006.11.007
Mark Laslett* Peter van der Wurff Evert Buijs Charles N. Aprill Moorhouse Medical Centre, PhysioSouth, Level 2, 3 Pilgrim Place, Christchurch, Canterbury, New Zealand *Corresponding author. Tel.: þ64 3 385 5446; fax: þ64 3 377 0614. E-mail address: [email protected] (M. Laslett) 19 August 2006 Available online 7 March 2007 DOI of original article: 10.1016/j.jbspin.2004.08.003 1297-319X/$ - see front matter Ó 2007 Elsevier Masson SAS. All rights reserved. doi:10.1016/j.jbspin.2006.11.006
Reply to the letter by Mark Laslett on the review entitled: ‘‘Provocative sacroiliac joint maneuvers and sacroiliac joint block are unreliable for diagnosing sacroiliac joint pain’’ Keywords: Sacroiliac joint; Diagnosis; Reference standard; Controlled blocks; Clinical tests
We thank Dr Laslett et al. for their enthusiastic comments, and do apologize for not including their recent works in our former review (which had been submitted more than two years ago) [1]. Our main goal was to stress the possibility of false positive results of sacroiliac blocks, related either to placebo/Hawthorne effects and/or communications between sacroiliac joints and surrounding tissues (including ligaments and nerves) [2]. In our opinion, this should still preclude their use as a gold standard (although they might deserve a ‘silver standard’ label). Indeed, too much confidence in those tests/blocks might lead to circular reasoning, and unnecessary fusion of sacroiliac joints for many patients with chronic back or buttock pain. In this respect, it should be kept in mind that the results of those fusions can be rather poor, even in patients with highly probable sacroiliac pain [3]. In other words, we think that the specificity of either clinical tests or a single diagnosis block should be even better than 0.80, to be considered reliable enough to prompt sacroiliac surgery and discard other explanations for chronic back pain. Although they recognized in their recent works that perfect gold standards did not exist for the diagnosis of discogenic, facetogenic pain, or pain arising from the SIJ [4], Laslett et al. seemingly did not check whether a leakage of the contrast medium out of the sacroiliac joint had occurred before considering their (single) sacroiliac block as positive [5,6]. Hence, it cannot be ruled out that some pain ascribed to the sacroiliac joint indeed arose from neighbouring tissues. The same holds true for the report by van der Wurff et al. [7], who performed two blocks (with a short and a long lasting anaesthetic) using 3 ml (1 cm3 of contrast medium and 2 cm3 of anaesthetic fluid), and did observe some leakages, even leading to temporary
307
sciatic palsy in five patients. We quite agree with the useful advice of Dr Laslett et al. to use no more than 0.5 cm3 of contrast media and 1 cm3 of anaesthetic fluid, although it should be checked whether when using such volume no leakage can still occur, and whether the relief of pain is equal to what has been observed with larger volumes [7]. The studies by Laslett et al. [4e6] have high scientific content, and are probably the most valuable breakthroughs on this frustrating topic. However, they would be even more convincing if it can be definitively proven that the phenomenon of centralization is so specific for pain of disc origin that no other diagnosis should be considered [8]. Indeed, the increased specificity of sacroiliac tests observed by Laslett et al. (up to 0.87) [5,6], compared with previous papers, has been favoured by the elimination from the control group of patients with a centralization phenomenon. This is an important point, as pain arising from the discs is probably the most frequent differential diagnosis to consider in patients with back/buttock pain. Similarly, the specificity of a test for diagnosing back/buttock pain should ideally be calculated using a control group representative of the whole population of patients with back/buttock pain. In another nice study by Laslett et al. [4] the authors observed in a sample of 216 chronic lumbar pain patients that only 67% could receive a patho-anatomic diagnosis based on available reference standards, 10% had more than one tissue origin of pain identified, and only 51% were given the same diagnosis by two physiotherapists. This underlines the difficulty of conducting such studies without rather strong selection bias of the control group, as also stressed by van der Wurff et al. in a previous response [9]. The second explanation for the discrepancies between recent results [5e7] and those summarized in our review [1], might be the threshold of pain relief required to consider a sacroiliac block as positive. For instance van der Wurff et al. [7] considered that a 50% reduction of pain was enough (compared with the threshold of 75% selected by Maigne et al. [10], and 80% by Laslett et al. [5]), which did offer a very clear split of patients between two groups of 27 responders and 33 nonresponders [7]. However, this should lead to the conclusion that 45% of chronic low-back pain originates from the sacroiliac joint stricto sensu, which appears rather improbable, and might cast doubt on the validity of the control group in this study too [7]. Indeed, figures from past works using a double-block paradigm, ranged from 10% to 19% [11]. To reconcile those observations, we proposed that many patients relieved by a sacroiliac block could indeed suffer from sacroiliac lato sensu, i.e. from surrounding ligaments, including ilio-lumbar ligaments, and suggested that explanations other than the sacroiliac joint itself should still be considered, even when several ‘sacroiliac’ provocation tests (which also stress lumbar structures) are positive [1]. This would be in agreement with the improvement induced in 13/18 patients with pain arising from the sacroiliac joint, by blocks of the L4e5 dorsal rami and S1e3 lateral branches [12] which innervate the ligaments surrounding the sacroiliac joint probably as much as the sacroiliac joint stricto sensu. Hence, we would quite agree with Dr Laslett that clinical tests (and perhaps
308
Correspondences / Joint Bone Spine 74 (2007) 306e308
sacroiliac blocks) should be more specific for ‘sacroiliac syndrome’ than for ‘sacroiliac joint pain’. References [1] Berthelot JM, Labat JJ, Le Goff B, Gouin F, Maugars Y. Provocative sacroiliac joint maneuvers and sacroiliac joint block are unreliable for diagnosing sacroiliac joint pain. Joint Bone Spine 2006;73:17e23. [2] Fortin JD, Washington WJ, Falco FJ. Three pathways between the sacroiliac joint and neural structures. AJNR Am J Neuroradiol 1999; 20:1388e9. [3] Schutz U, Grob D. Poor outcome following bilateral sacroiliac joint fusion for degenerative sacroiliac joint syndrome. Acta Orthop Belg 2006;72:296e308. [4] Laslett M, McDonald B, Tropp H, Aprill CN, Oberg B. Agreement between diagnoses reached by clinical examination and available reference standards: a prospective study of 216 patients with lumbopelvic pain. BMC Musculoskeletal Disord 2005;6:28. [5] Laslett M, Young SB, Aprill CN, McDonald B. Diagnosing painful sacroiliac joints: a validity study of a McKenzie evaluation and sacroiliac provocation tests. Aust J Physiother 2003;49:89e97. [6] Laslett M, Aprill CN, McDonald B. Provocation sacroiliac joint tests have validity in the diagnosis of sacroiliac joint pain. Arch Phys Med Rehab 2006;6:874e5. [7] Laslett M, Oberg B, Aprill CN, McDonald B. Centralization as a predictor of provocation discography results in chronic low back pain, and the influence of disability and distress on diagnostic power. Spine J 2005;5:370e80. [8] Van der Wurff P, Buijs EJ, Groen GJ. A multitest regiment of pain provocation tests as an aid to reduce unnecessary minimally invasive sacroiliac joint procedures. Arch Phys Med Rehabil 2006;87:10e4.
[9] van der Wurff P, Buijs EJ, Gerbrand J, Groen GJ. The authors respond. Arch Phys Med Rehabil 2006;87:874e5. [10] Maigne JY, Planchon CA. Sacroiliac joint pain after lumbar fusion. A study with anesthetic blocks. Eur Spine J 2006;15:8e15. [11] McKenzie-Brown AM, Shah RV, Sehgal N, Everett CR. A systematic review of sacroiliac joint interventions. Pain Physician 2005;8: 115e25. [12] Cohen SP, Abdi S. Lateral branch blocks as a treatment for sacroiliac joint pain: a pilot study. Reg Anesth Pain Med 2003;28:113e9.
Jean-Marie Berthelot* Hoˆtel-Dieu-CHU Nantes, 1, Place Alexis Ricordeau, Nantes Cedex 01, France *Correspondence author. Rheumatology Unit, Nantes University Hospital (CHU Nantes), 44093, Nantes, France. Tel.: þ33 02 40 08 48 22/25/01; fax: þ33 02 40 08 48 30. E-mail address: [email protected] 19 September 2006 Available online 5 March 2007 DOI of original article: 10.1016/j.jbspin.2004.08.003 1297-319X/$ - see front matter Ó 2007 Elsevier Masson SAS. All rights reserved. doi:10.1016/j.jbspin.2006.11.007