Klinika Fizjoterapii, Reumatologii i Rehabilitacji Akademii Medycznej im. Karola Marcinkowskiego ul. 28 Czerwca 1956 roku 135/147, 61-545 Poznań
Kierownik prof. dr hab. n. med. Włodzimierz Samborski
Streszczenie
Rwa kulszowa charakteryzuje się promieniującym bólem od okolicy krzyżowo-lędźwiowej do pośladków i dalej do kończyny dolnej. Wśród przyczyn ischialgii zwykle wymie-nia się zmiany degeneracyjne kręgosłupa oraz uszkodzewymie-nia krążków międzykręgowych. Wtórna objawowa rwa kulszo-wa może być spowodokulszo-wana przerzutami nowotworowymi do kręgosłupa, gruźlicą kręgów, guzami znajdującymi się w kanale kręgowym czy zakleszczeniem nerwu kulszowego w mięśniu gruszkowatym. Zespół mięśnia gruszkowatego wywołany jest pierwotnie urazem podczas upadku, jednak są możliwe inne przyczyny, jak ropne zapalenie mięśni, dystonia mięśniowa zniekształcająca czy zwłóknienie spo-wodowane głębokimi iniekcjami. Do przyczyn wtórnych zalicza się podrażnienie stawu krzyżowo-biodrowego oraz zgrubienie przy wcięciu kulszowym. W praktyce ogólnej zwykle spotyka się tak zwany pourazowy zespół mięśnia gruszkowatego. Właściwe leczenie należy poprzedzić do-kładnym ustaleniem przyczyny objawów.
H a s ł a: mięsień gruszkowaty – ischalgia – leczenie.
Summary
Sciatica is characterized by radiating pain from the sacro-lumbar region to the buttocks and down to the lower limb. The causes of sciatica usually relate to degenera-tive changes in the spine and lesions to the intervertebral discs. Secondary symptomatic sciatica may by caused by metastases to the vertebra, tuberculosis of the spine, tumors located inside the vertebral channel, or entrapment of the sciatic nerve in the piriformis muscle. The piriformis
syn-drome is primarily caused by fall injury, but other causes are possible, including pyomyositis, dystonia musculorum deformans, and fibrosis after deep injections. Secondary causes like irritation of the sacroiliac joint or lump near the sciatic notch have been described. In the general practice the so-called posttraumatic piriformis muscle syndrome is common. The right treatment can be started following a thorough investigation into the cause of symptoms.
K e y w or d s: piriformis muscle – sciatica – treat-ment.
Sciatica is characterized by pain radiating from the sacro-lumbar region to the buttocks and the lower limb. The causes of sciatica usually include degenerative changes in the spine as well as lesions to the intervertebral discs. Sec-ondary symptomatic sciatica may by caused by metastases to the vertebra, tuberculosis of the spine, tumors located inside the vertebral channel, or entrapment of the sciatic nerve in the piriformis muscle.
The first description of sciatica has been given by Hippocrates who described it as a state caused by different factors and lasting for about 40 days [1]. In 1928, Yeoman [2]
reported that 36% of sciatica cases are due to degeneration of the sacroiliac joint. Changes in the piriformis muscle, sac-roiliac ligament, and adjacent branches of the sciatic nerve may contribute to the etiology of the piriformis syndrome.
This report was ignored after it was discovered in 1934 that the so-called sciatica is caused by herniated nucleus pulposus. Nevertheless, Freiberg and Vinke [3] suggested, considering individual anatomic differences of piriformis and sciatic nerve, that in some patients the cause of sciatica is neuropathy of the sciatic nerve caused by entrapment of this nerve in the piriformis muscle.
100 ELŻBIETA KUNCEWICZ, EWA GAJEWSKA, MAGDALENA SOBIESKA, WłODZIMIERZ SAMBORSKI The piriformis muscle usually lies on the front side of
the vertebral surface (S1, S2, S3) and the sacroiliac capsule, the front part of posterior inferior iliac spine and often the upper part of the sacrotuberous ligament. The muscle exits the pelvis through the greater sciatic notch and touches the greater trochanter of the femoral bone (Fig. 1). It is important functionally as it stabilizes the sacroiliac joint and it is an external rotator of the iliac joint when the thigh is extended, whereas it serves as an abductor of the iliac joint when the thigh is flexed [4, 5].
show different mechanisms in the etiology of this disorder.
Foster supports Robinson in the theory, that the piriformis syndrome is primarily caused by fall trauma, but among other causes there is pyomyositis, dystonia musculorum deformans, and fibrosis after deep injections [7, 8, 9, 10, 11, 12]. As a secondary cause, Robinson mentions irrita-tion of the sacroiliac joint or appearance of a lump near the sciatic notch [9, 13]. Epidemiological research has shown that women are more predisposed to this disorder (6:1), especially those complaining of dyspareunia. A suggested explanation is that it is a remnant after dysfunction of the sacroiliac joint in childhood [14].
Practically, the most frequent is the so-called posttrau-matic piriformis muscle syndrome, e.g. caused by falling.
However, there are some hypotheses that explain the mecha-nism of its etiology. Robinson [9] claims that the injury causes inflammation of muscle and fascia, their swelling, and as a result entrapment of the sciatic nerve. Another hypothesis assumes that people whose nerve or one of its branches passes through the piriformis muscle are at risk of pressure on the nerve by the body of piriformis muscle or by its tendon during external rotation of the iliac joint (Fig. 2). Another hypothesis assumes that trigger points in the piriformis muscle may irritate the muscle [14].
Fig. 1. Topography of the piriformis muscle and sciatic nerve [5]
Ryc. 1. Topografia mięśnia gruszkowatego i nerwu kulszowego [5]
Fig. 2. Pressure on the sciatic nerve by the piriformis muscle or its tendon during external rotation [5]
Ryc. 2. Ucisk nerwu kulszowego przez napięty mięsień lub ścięgno podczas rotacji zewnętrznej w stawie biodrowym
Anatomic research showed that there are big interper-sonal differences regarding the structure of this muscle and the course of the sciatic nerve. However, these structures are at the same time strongly inter-related [6]:
1) in 90% of subjects the sciatic nerve passes distally in relation to the piriformis muscle;
2) 7% have their piriformis muscle divided into two parts, with one branch of the sciatic nerve passing through the spit and the other branch passing distally to the piri-formis muscle;
3) in 2% of subjects, the nerve branches proximally to the piriformis muscle, with one branch of the nerve pass-ing distally to the muscle and the other branch passpass-ing proximally;
4) in 1% of subjects, the piriformis muscle is divided with the sciatic nerve passing through its midportion.
At present, there is the consensus that the piriformis muscle syndrome does exist. However, many case reports
Most researchers support the conclusions of Robinson who also gives six typical features of posttraumatic piri-formis syndrome:
1) pain appears after falling on the buttocks;
2) pain is localized to the sacroiliac joint, sciatic notch and piriformis muscle, and radiates along the leg;
3) pain intensifies while bending and straightening;
4) there is a callosity above the piriformis;
5) there is a positive Lasseque sign;
6) glutei muscles are atrophic [9].
Irrespective of the causes, with the aid of available clinical diagnostic methods, the piriformis syndrome can be unequivocally differentiated from other disorders causing
PIRIFORMIS MUSCLE SYNDROME 101 sciatica. With the lack of symptoms indicating spinal origin
of sciatic nerve irritation one must check digital palpation hy-persensitivity along the course of piriformis, especially when the intensification of complaints appears while sitting and walking on rough surfaces. Secondly, symptoms indicated by Robinson should be checked [9]. Piriformis syndrome is finally confirmed by four clinical tests: tests B, C, D only considered positive with reproduction of sciatica.
1. An asymmetric posture of the extended limb in the supine patient resulting from external rotation of the ef-fected limb.
2. The Freiberg test forces internal rotation with the thigh in extension.
3. The Pace test evaluates loss of function, weakness, and pain on resisted abduction of the flexed thigh.
4. The combined abduction, external rotation test was most consistent and positive in all patients.
Detailed diagnostics indicating precisely the cause of disorder requires the use of computerized axial tomography or magnetic resonance imaging. There are many efficient treatment methods beside surgery [15, 16, 17, 18, 19]. In order to alleviate inflammation and muscle tone, non-steroidal anti-inflammatory agents are recommended, on condition that injections are done with care. Local intramuscular in-jections are recommended only when nonsurgical methods like physiotherapy, ultrasound, exercises, or massage fail.
Treatment is usually very effective but requires prompt di-agnosis. Patients who do not respond to this kind of therapy are referred for surgery. It should also be mentioned that in the case of secondary piriformis syndrome treatment should include the sacroiliac joint.
References
1. Breasted J.H.: The Edwin Smith Surgical Papyrus. University of Chi-cago Press, ChiChi-cago 1930.
2. Yeoman W.: The relation of arthritis of the sacro-iliac joint to sciatic, with an analysis of 100 cases. Lancet. 1928, 1119−1122.
3. Freiberg A.H., Vinke T.H.: Sciatica and the sacro-iliac joint. J. Bone Joint Surg. 1934, 16, 126−136.
4. Lee D.: Obręcz biodrowa. Badanie i leczenie okolicy lędźwiowo-mied-niczno-biodrowej. DB Publishing, Warszawa 2001, 48−49.
5. www.neurography.com (5.01.2006).
6. Beaton L.E., Anson B.J.: The sciatic nerve and the piriformis muscle:
their interrelation a possible cause of coccygodynia. J. Bone Joint Surg.
1938, 20, 686−688.
7. Benson E.R., Schutzer S.F.: Posttraumatic Piriformis syndrome: Dia-gnosis and results of operative treatment. J. Bone Joint Surg. 1999, 8, 7, 941−949.
8. Foster M.R.: Piriformis syndrome. Orthopedics, 2002, 25, 8, 821−825.
9. Robinson D.R.: Pyriformis syndrome in relation to sciatic pain. Am.
J. Surg. 1947, 73, 355−358.
10. Chen W.S.: Sciatica due to piriformis pyomyositis. Report of a case. J.
Bone Joint Surg. Am. 1992, 74, 1546−1548.
11. Beauchesne R.P., Schutzer S.F.: Myositis ossificans of piriformis mu-scle. An unusual cause of piriformis syndrome. A case report. J. Bone Joint Surg. Am. 1997, 79, 906−910.
12. Gandhavadi B.: Bilateral piriformis syndrome associated with dystonia musculorum deformans. Orthopedics. 1990, 13, 350−351.
13. Vandertop W.P., Bosma N.J.: The piriformis syndrome. A case report.
J. Bone Joint Surg. Am. 1991, 73, 1095−1097.
14. Pace J.V., Nagle D.: The piriformis syndrome. West J. Med. 1976, 124, 435−439.
15. Pecina M.: Contributions to the etiological explanation of the piriformis syndrome. Acta Anat. 1979, 105, 181−187.
16. Barton P.M.: Piriformis syndrome: a rational approach to management.
Pain. 1991, 47, 345−352.
17. Hallin R.P.: Sciatic pain and the piriformis muscle. Postgrad. Med.
1983, 74, 69−72.
18. Hughes S.S., Goldstein M.N., Hicks D.G., Pellegrini V.D. Jr.: Extrapelvic compression of the sciatic nerve. An unusual cause of pain about the hip: report of five cases. J. Bone Joint Surg. 1992, 74-A, 1553−1559.
19. Melzack R.: Prolonged relief of pain by brief, intense transcutaneous somatic stimulation. Pain, 1975, 1, 357−373.
Komentarz
W pracy przedstawiono analizę „zespołu mięśnia gruszkowatego”. Zespół ten jest nieco zapomniany jako przyczyna bólu krzyża, o tym świadczy chociażby dość odległa w czasie cytowana literatura.
O zespole mięśnia gruszkowatego pamiętać należy w diagnostyce bólu krzyża. Bólem krzyża zajmują się le-karze różnych specjalności oraz przedstawiciele zajmujący się terapią manualną („nastawianie”) i fizykoterapią. Dla lekarza praktyka przypomnienie jeszcze jednej przyczyny bólu krzyża jest bardzo istotne. W możliwościach leczenia należy dodatkowo wspomnieć o metodzie ostrzykiwania mięśnia gruszkowatego nowokainą. Iniekcji dokonuje się pod kontrolą wprowadzonego palca do odbytnicy wymacu-jącego bolesne miejsce. Autorom należy pogratulować za przypomnienie jeszcze jednej przyczyny bólu krzyża.
prof. dr hab. n. med. Irena Fiedorowicz-Fabrycy
ANNALES ACADEMIAE MEDICAE STETINENSIS
R O C Z N I K I P O M O R S K I E J A K A D E M I I M E D Y C Z N E J W S Z C Z E C I N I E ANNALS OF THE POMERANIAN MEDICAL UNIVERSITY
2006, 52, 3, 103–114
JOANNA ZIółKOWSKA