painful fabella syndrome, case report and literature … · painful fabella syndrome, case report...

PAINFUL FABELLA SYNDROME, CASE REPORT AND LITERATURE REVIEW

Indira ArianiInstitution : Radiology Installation,

Pratama Hospital Yogyakarta, Indonesiaemail: [email protected]

Painful Fabella Syndrome, Case Report and Literature Review, Indira Ariani

Background

• Fabella is sessamoid bone, found in 10-30% population

• Some cases bilateral • Fabella is located in fossa

posterolateral articulatio genu in the surface of posterior condylus lateralis femoralis

• It is surrounding by tendon of caput musculus gastrocnemius


Background

• Anterior fabella is bordered with posterior capsule of knee joint

• Posterior fabella is located in end point of ligamentum popliteal oblique and lateral to gastrocnemius tendon.

• Ligamentum fabellofibular (ligamentum vallois ) runs from distal insersion of caput fibula.

• The size of fabella normally < 5 mm in diameter (calliper measurement)

• Asian population has high prevalence of fabella


Background

• Fabella has similar function as patella: support knee flexion strength

• Posterior fabella may cause several clinical abnormality: fabellar pain syndrome, chondromalacia fabellae dan fabella fracture.

• Big fabella may associate with neurologic injury from nervus fibularis communis


Background

• Fabella posterior syndroma is a rare condition.• It is associated with posterior knee pain

caused by mechanical iritation in the surrounding area in posterolateral knee area and “click” sound in knee flexion


Case Report

Identity• A woman age 46 years old• Profesion: a hospital nutrisionist, actively

moving• Usually working upstair and downstair to see

patients


Case Report

• Complaint :backside knee pain pain location: outside part of fossa poplitea, radiating to leg pain duration: intermittent, increased intensity while genu flexion and “click” sound heard while genu flexion pain chronicity: already suffered 1 year no history of knee trauma


Case Report

• Physical examination:Inspection: no knee swelling, no redness Palpation: no warm, mass or lump. Palpation in lateral part of posterior aspect no pain. Deep palpation with pressure in fibular proximal part in iliotibial track and biceps femoris create mild pain.

• Patient is referred by Internist to get imaging examination


Case Report

• Left knee X-ray : no soft tissue swelling or mass opacity in around the genubone structure and trabeculation good, cortex and medulla intact, facies articularis, cortex dan medulla tampak intak, facies articularis smooth, joint space not narrowed, no appearance of subchondral sclerosis or erosi/osteophyt

In the lateral projection: the appearance of posterior fabella with early sclerotic in the facies anterior of fabella


Case Report

• Lateral projection knee X ray (sinistra): Posterior fabella with early sclerotic in facies anterior of fabella


Case Report

• Ultrasonography findingNo abnormality of anterior, medial and lateral structuresIn posterior structure: no Baker cyst, tumor or other structural abnormalityIn posterior condylus lateralis femur: fabella appears inside the tendon of lateral head of musculus gastrocnemius, it produce pain in probe pressure in the area


Case Report

• Ultrasononography of posterior condylus lateralis femur:fabella appears inside the tendon of lateral head of musculus gastrocnemius


Case Report• Magnetic Resonance Imaging

appearance of very minimal fluid in the intercondylaris spaceIn proton density, there is hipointens in bone marrow femur contralateral to fabella, indicated by hiperintens appearance in STIR. The hiperintens appearance on facies articularis fabella can not be identified and only can be shown the appearance of irregularity facies articularis in condylus lateralis femur contralateral to fabella. Fabella appears in distance from neurovascular structure.


Case Report

• MRI:appearance of very minimal fluid in the intercondylaris spaceIn proton density, there is hipointens in bone marrow femurcontralateral to fabella


Case Report

• MRI :appearance of very minimal fluid in the intercondylaris spaceIn proton density, there is hipointens in bone marrow femurcontralateral to fabella, indicated by hiperintens appearance in STIR.


Case Report

• Patient is treated with local steroid+anaestetic injection guided by ultrasonography.

• Patient feels better and can resume activity after injection


Discussion

• Fabella is located in the tendon of lateral head of muscullus gastrocnemius and directly associated with facies articularis in the surface of posterior condylus lateralis femur.

• The case has same location of fabela. It is located in the tendon of lateral head of muscullus gastrocnemius and directly associated with facies articularis in the surface of posterior condylus lateralis femur.


Discussion

• Kawashima et al, reported in cadaver that ossification and endochondral fabella more common in the lateral head of musculus gastrocnemius compared with medial head.

• The ossification is progressed overtime.• The case has same pattern, onset of fabella

pain syndroma in decade IV and anatomical location of fabella is in the lateral head of musculus gastrocnemius.


Discussion• Main symptom of fabella posterior syndroma is pain

caused by local soft tissue irritation during knee extension which caused tension due to pressure from fabella in lateral condylus femur.

• Main symptom due to: mechanical iritation and pressure, fabella pressure, clicking and crepitation in posterolateral aspect of knee during genu flexion and extension.

• The tenderness of fabella is caused by pressure in fabella that reach condylus lateralis femur.

• The pattern in similar in the patient, the pain in similar location and pain appear in probe pressure.


Discussion

• From case series of 18 fabellectomy :Chondromalacia macroscopic changes in 10 cases, Chondromalacia microscopic changes in 2 casesThe tendon thickening is excised in 5 patientsNon operatif treatment in 7 patients


Discussion

• Fabella pain syndroma clinical diagnosis: - clinical history- physical examination- radiography- ultrasonography- scan radionucleotide - MRI.

MRI : local degenerative changes or chondromalacia fabella


Discussion

• The cause of ekstra and intraartikuler pain in posterolateral knee are: baker’s cyst, foreign bodies, meniscus ruptur, osteochondral fragment, and local pigmented villonodular synovitis.

• Pain syndroma similar to fabella pain syndroma and may be co exist are : gout, knee fractur, bursitis, tendinitis.


Discussion

• Case with pure degenerated fabellofemoral is rare.

• There is only 1.1 % cases identified in 56-79 years old patients.

• Cartilaginous lesion can only be identified with MRI, with the appearance of defect in cartilago articularis contralateral to fabella and changes in subchondral bone marrow.

• In this case, fabella position is in distance from neurovascular structure


Discussion

• Definitive treatment of fabella pain syndrome is surgery to remove fabella (fabelectomy).

• Non surgery intervention is only temporarlity alleviate the pain

• Non surgery and conservative treatment include local steroid injection, immobilisation, analgesics and restriction of physical activity.

• The case undergoes conservative treatment and the result is satisfactory.


Conclusion

• We report a case, woman 46 years old with main complaint of chronic and intermittent left knee pain in the popliteal fossa radiating to leg.

• The knee ultrasonography and MRI definitely diagnosed as pain fabellar syndroma.

• Local steroid and anestetic injection guided by ultrasonography is effective to alleviate the pain.


Reference• Duncan W, Dahm DL. 2003. Clinical anatomy of the fabella. Clin Anat. 16(5):448-449.• Sarin VK, Erickson GM, Giori NJ, Bergman AG, Carter DR. 1999. Coincident development of sesamoid bones and

clues to their evolution. Anat Rec. 257:174-180.• Driessen A, Balke M, Offerhaus C, White WJ, Shafizadeh S, Becher C, Bouillon B, Höher J. 2014. The fabella

syndrome-a rare cause of posterolateral knee pain: a review of the literature and two case reports. BMC Musculoskel Dis, 15(1);100.

• Okano E, Yoshioka T, Yanai T, Kohyama S, Kanamori A, Yamazaki M, Tanaka T. 2016. Fabella syndrome as an uncommon cause of posterolateral knee pain after total knee arthroplasty: a case report and review of the literature. Case Rep Orthop. 2016:4328462.

• Kawashima T, Takeishi H, Yoshitomi S, Ito M, Sasaki H. 2007. Anatomical study of the fabella, fabellar complex and its clinical implications. Surg Radiol Anat. 29(8):611-616.

• Müller W.1982. The knee - form, function and ligament reconstruction. In Knee- Form, Funct Ligament Reconstr. New York: Springer Verlag Berlin Heidelberg; pp. 40, 96, 98, 192, 249, 252.

• Weiner DS, Macnab I. 1982. The “Fabella syndrome”: an update. J Pediatr Orthop 2:405– 408.• Legendre P, Fowles JV, Godin C. 1986. Chondromalacia of the fabella: a case report. Can J Surg 29:102–103.• Marks PH, Cameron M, Regan W. 1998. Fracture of the fabella: a case of posterolateral knee pain. Orthopedics.

21:713–714.• Jaffe FF, Kuschner S, Klein M. 1988. Fabellar impingement: a cause of pain after total knee replacement. A case

report. J Bone Joint Surg Am. 70(4):613-616. • Ehara S. 2014. Potentially symptomatic fabella: MR imaging review. Jpn J Radiol. 32(1):1-5. • Kuur E. 1986. Painful fabella, a case report with review of literature. Acta Orthop Scand. 57:453-454. • Zipple JT, Hammer RL, Loubert PV. 2003. Treatment of fabella syndrome with manual therapy: a case report. J

Orthop Sports Phys Ther. 33(1):33-39


painful fabella syndrome, case report and literature … · painful fabella syndrome, case report...

Documents