Piriformis SyndromeAre We Missing It?

Dr. Jayant Sharma MS (ortho) ,DNB, MNAMS Consultant (Sports Medicine)

Introduction In the United States each year, 1.5 million people have lumbar MRI scans to look

for the cause of the buttock and leg pain called 'sciatica'.

More than 1.2 million of those scans fail to find the cause in the spine.

Three hundred thousand of the scans are sufficiently positive that the patient has lumbar spine surgery. Of the 300,000 surgeries, as many as 25% fail to relieve the pain

In many cases this is because the diagnosis of a spinal cause for the sciatica was incorrect.

www.neurography.com/Images/Piriformis/Piriformis1

Introduction Piriformis syndrome also causes

sciatica. Its treatment is much less invasive and severe than the treatment of herniated lumbar disks. However, many doctors never consider piriformis syndrome as a possible diagnosis. Many physicians who are aware of it are uncertain how to properly diagnose and treat it.

The muscle

Origin Insertion Its relation to sciatic nerve

Abnormal anatomy

Approximately 15% of Cadavers exhibit that instead of Sciatic Nerve passing below the muscle it,

Passes through Or Above the Piriformis.

Pathophysiology

Pecina : Hypothesized that Sciatic Nerve passing thru Tendinous portion of Piriformis is susceptible to compression.

Pace & Nigle : Myofascial pain syndromes caused by trauma.

McCrory : “PELVIC OUTLET SYNDROME”; due to extra spinal compression.

Mccory P, Bell.S-Sports Medicine 1999:27:261-74.Mccory P, Bell.S-Sports Medicine 1999:27:261-74.

CausesOVERLOAD: Exercise on hard

surface Exercise on uneven

surface Exercise after long

layoff Exercise with worn

out shoes Prolonged Sitting

BIOMECHANICSBIOMECHANICS:: On toe running On toe running

Banked road runningBanked road running

Stiff back musclesStiff back muscles

AIMS

To study the patients of radicular low backache for Pirifomis syndrome

To follow up these cases for 6 months and evaluate the present protocol of management.

Materials and methods

This study was conducted at AHRC, Indore from Feb. 06 to July 2006.

All patients complaining of low backache at Ortho OPD,LBA Clinic, and sports medicine clinic were considered for screening for Piriformis syndrome.

ClassificationA.PrimaryMyofascial pain caused by trauma.

B. Secondary Tumors Endometreosis Adhesions of T.H.R. Inflammation Malunited fractures Pelvic Outlet Syndrome

Papadopoulos SM, Arch Neurl.1990-1144-6Papadopoulos SM, Arch Neurl.1990-1144-6

Diagnostic criteria

History C/O - pain radiating to ipsilateral

hip, thigh, below knee. Exacerbated by activity -

adduction & internal rotation. Sitting Intolerance.

FADIR TEST STRECHING TEST OF FREIBERG PACE TEST - lying with painful buttock up

and knee on table, resisted lifting up of knee in fixed position elicits pain, rules out pain of O.A., Disc

SLRT +ve with relief of pain on ER. P/R Examination - tender mass spindle

shaped, this is the intrapelvic part of the muscle

FAdIR

PACE PACE

In few cases when patient showed strong clinical signs and was not responding to physiotherapy, we asked for an MRI.

No role of X-rays,Neurophysiological Tests are

consistent with Peroneal Division of Sciatic Nerve.

Nerve conduction shows delayed F&H waves reflex.

MRI is diagnostic

Treatment protocolFor first 72 hrs Rest NSAIDS Muscle relaxants ULTRASONIC MASSAGEAfter 72 hrs Stretching DTFM US Massage

After two weeks Local injection(3)1. LA2. LA + Depo medrol3. Perisciatic

Parziale J, American Journ.Orthop,1996;25,819-23Parziale J, American Journ.Orthop,1996;25,819-23

Surgery

Robinson Piriformis muscle release Sciatic nerve Neurolysis. No effect on power of the external

rotators and abductors of hip. Position - Lateral Incision - Posterior approach

(Southern’s)

Steps - insertion of piriformis is palpated after splitting gluteus maximus.

Tendon is palpated and divided & grasped with Allis forceps, and dissected till its exit at Sciatic notch.

Full weight bearing in 5-10 days.

Avoid prolonged sitting for 4-6 weeks.

Neurotoxin Clostridium botulinum Inhibits release of Acetylcholine Leads to functional denervation of

muscles Effective for SIX months U.S.F.D.A.approved since December

2000.

Botox

Observations Total patients of LBA- 754 Patients of PS 67 11 males and 56 females (1:5) 36 right sided and 31 left sided No. of patients with significant reduction of

pain on VAS at two weeks- 50 At four weeks 64 17 patients were subjected to injections Of the remaining four two lost to f/up Two were subjected to MRI and when

confirmed they were operated.

Conclusion Piriformis syndrome is underdiagnosed

and undertreated entity. It is easy to diagnose with few physical

signs. When in doubt ask for an MRI The radiologist should be asked to look for

piriformis syndrome while screening the spine

With this many cases can be saved from undergoing surgery.

Take home message

Piriformis syndrome should be considered

as an important differential diagnosis in backache patients.

With best wishes

ARIHANT HOSPITAL AND RESEARCH CENTRE, INDORE