A pain in the butt… A guest blog by Dr Chris Littlewood

I regularly hear therapists using the diagnosis of ‘Piriformis Syndrome’ to explain to patients their stubborn buttock and sciatic like pains. However, as usual I question this diagnosis, I question its true prevalence, I question the ability of therapists to diagnose it clinically and I really question those who think it needs to be treated by digging elbows, needles or cricket balls into patients backsides!

Piriformis tweet

And I am not alone in questioning this diagnosis, I recently found this good debate on Piriformis Syndrome in which both sides of over or under diagnosis argument are presented and it makes for good reading. I posted this on Twitter a few weeks ago (see above) and following this Dr Chris Littlewood kindly sent me some work he had done on the subject and so I thought I would share it with you.

Regular readers of my blog will know Chris as he kindly did another great blog for this site here questioning scapula stability rehab. Since this blog was posted he has earned his PhD looking at a self management approach for Rotator Cuff tendinopathy and continues to work at Sheffield University as a NIHR research fellow, he can be followed on twitter here, so without further ado, here is Chris’s look at Piriformis Syndrome.

PS, please try and overlook the fact that Chris is pictured assessing in a tie… apparently he tells me it aids in patient satisfaction or something… ;o)

The ‘Piriformis Syndrome’ by Chris Littlewood 

Introduction

In 1928 Yeoman introduced the idea that ‘sciatic’ type symptoms may be caused by extra-spinal compression of the sciatic nerve as it passes through the Piriformis muscle (McCrory, 2001). In 1947 Robinson coined the term Piriformis Syndrome to describe this clinical presentation (Benson & Schutzer 1999).

Diagnosis

Despite its longevity Piriformis Syndrome remains a controversial diagnosis (Thomas-Byrd 2005, Silver & Leadbetter 1998). When Robinson introduced the term Piriformis Syndrome 6 cardinal features were described to aid formulation of the diagnosis:

• History of trauma to the gluteal region
• Pain in the region of sacroiliac joint, greater sciatic notch or Piriformis muscle with or without leg pain provoked when walking
• Acute exacerbation through lifting or stooping with some relief through traction
• Palpable tenderness of the Piriformis muscle
• Positive Lasegue (Straight leg raise) sign
• Possible gluteal atrophy (Parziale et al 1996).

Upon review of the cases presented within the literature it is clear that this clinical diagnostic criteria has not prevailed (Nakamura et al, 2003, Kosukegawa et al 2006, Parziale et al 1996). Due to this diagnostic uncertainty a true or accurate epidemiological perspective of the syndrome for example prevalence rates, natural history are not forthcoming. However there is a common theme within the literature that suggests Piriformis Syndrome is not a common problem (Read 2002).

More recently common themes have emerged to aid diagnosis:

• Palpable tenderness of the Piriformis muscle with or without production of ipsilateral leg pain
• Positive FADIR (pain reproduced with flexion/ adduction/ internal rotation of the affected hip) test – Figure 1
• Positive Pace sign (pain reproduced with resisted external rotation and abduction of the affected hip) – Figure 2

(Benson & Schutzer 1999, Fishman et al 2002, Kosukegawa et al 2006, Nakamura et al 2003, Parziale et al 1996, Silver & Leadbetter 1998).

Piriformis FADIR

Figure 1 FADIR test (pain with flexion/ adduction/ internal rotation of the hip)

Piriformis PACE

Figure 2 Pace sign (pain with resisted hip abduction/ external rotation)

Tests using electrophysiology or advanced imaging have been advocated to confirm the diagnosis where clinical tests have proven positive, (Fishman & Zybert 1992, Jankiewicz et al 1991, Papadopoulos et al 1990). Nakamura et al (2003) utilised an electrophysiological method using the H-reflex. In this study action potentials were initially recorded in a position of hip extension and then subsequently in a position of combined hip flexion/ adduction/ internal rotation (FADIR). When the piriformis muscle was in a position of stress (FADIR) the potential was reduced, indicating neural compression, which may be suggestive of a positive diagnosis. Advanced imaging e.g. MRI and CT have been used to identify an enlarged piriformis muscle (Jankiewicz et al 1991) or other forms of extra-spinal compression of the sciatic nerve such as pseudoaneurysm of the inferior gluteal artery (Papadopoulos et al 1990). However these imaging techniques are predominantly used as a means of excluding intra-spinal compression as a source of pain (Parziale et al 1996) thus often rendering piriformis syndrome as a diagnosis by exclusion (Caldwell et al 1999, Parziale et al 1996).

Management

Where uncertainty exists with regards to diagnosis of a condition it can be expected that uncertainty exists with regard to its management. Current literature provides only anecdotal evidence and outcomes from case studies or case series, all of which lack significant validity.

A range of proposals are offered:

• Stretching/ strengthening of the piriformis muscle (Christensen 2006, Parziale et al 1996)
• Correction of altered lower limb biomechanics/ foot posture (Danchik 2001)
• Nonsteroidal anti-inflammatories, analgesics or muscle relaxants (Parziale at al 1996)
• Local injection therapy, including:
Local anaesthetic/ Steroid (Jankiewicz et al 1991)
Botox (Klein 2006)
• Surgical resection (Benson & Schutzer 1999, Nakamura et al 2003, Kosukegawa et al 2006)

In summary, although some progress has been made with regard to clinical recognition of this syndrome, it is not possible to advocate any one or any combination of the above treatment methods based upon current evidence.

Conclusion

Piriformis syndrome remains controversial in terms of the acceptance of its validity as a clinical entity, appropriate diagnosis and effective treatment.

Reference List

Benson E, Schutzer S 1999. Posttraumatic piriformis syndrome: Diagnosis and results of operative treatment. Journal of bone and joint surgery. 81(7), p. 941-949.

Caldwell S, Hurwitz E, Adams A 1999. Piriformis syndrome: An annotated bibliography. The journal of the Canadian chiropractic association. 43(3), p. 176-182.

Christensen K 2006. Rehab recommendations for piriformis syndrome. Dynamic Chiropractic 24(1), p. 21/37.

Danchik J 2001. Pronation, posture and piriformis syndrome: Putting the foot down on sciatica. Journal of the American chiropractic association. 38(3), p. 18-20.

Fishman L, Dombi G, Michaelsen C et al, 2002. Piriformis syndrome: diagnosis, treatment and outcome – a 10 year study. Archives of physical medicine and rehabilitation. 83(3) p. 295-301.

Fishman L, Zybert P 1992. Electrophysiological evidence of piriformis syndrome. Archives of Physical Medicine and rehabilitation. 73, p. 359-364.

Jankiewicz J, Henrikus W, Houkom J 1991. The appearance of the piriformis muscle syndrome in computed tomography and magnetic resonance imaging. A case report and review of the literature. Clinical orthopaedics and related research. 262, p. 205-209.

Klein M 2006. Piriformis syndrome. Available: http://www.emedicine.com/pmr/topic106.htm.

Kosukegawa I, Yoshimoto M, Isogai S et al, 2006. Piriformis syndrome resulting from a rare anatomic variation. Spine 31(18), p. E664-E666.

McCrory P 2001. The ‘piriformis syndrome’ – myth or reality? British journal of sports medicine. 35(4), p. 209-210.

Nakamura H, Seki M, Konishi S et al, 2003. Piriformis syndrome diagnosed by cauda equina action potentials. Spine. 28(2), p. E37-E40.

Papadopoulos S, McGillicuddy J, Albers J 1990. Unusual causes of ‘piriformis syndrome.’ Archives of Neurology. 47, p. 1144-1146.

Parziale J, Hudgins T, Fishman L 1996. The piriformis syndrome. The American Journal of Orthopaedics. December p. 818-823.

Read M 2002. The ‘piriformis syndrome’ – myth or reality? Letters. British journal of sports medicine. 36(1), p. 76.

Silver J, Leadbetter W 1998. Piriformis syndrome: Assessment of current practice and literature review. Orthopaedics. 21(10), p. 1133-1135.

Thomas-Byrd J 2005. Piriformis syndrome. Operative techniques in sports medicine. 13(1), p. 71-79.