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The fabella syndrome - a rare cause of posterolateral knee pain: a review of the literature and two case reports

Arne Driessen12, Maurice Balke2, Christoph Offerhaus3, William James White4, Sven Shafizadeh2, Christoph Becher5, Bertil Bouillon2 and Jürgen Höher6*

Author Affiliations

1 Institute for Research in Operative Medicine (IFOM), University of Witten/Herdecke (Campus Cologne-Merheim), Ostmerheimerstr. 200, 51109 Cologne, Germany

2 Department of Orthopaedic Surgery, Traumatology and Sports Traumatology, Cologne-Merheim Medical Centre (CMMC), University of Witten/Herdecke (Campus Cologne-Merheim), Ostmerheimerstr. 200, 51109 Cologne, Germany

3 St. Vinzenz Hospital, Klinik für Unfallchirurgie, Hand- & Wiederherstellungschirurgie, Merheimer Str. 221-223, 50733 Köln-Nippes, Germany

4 Department of Trauma and Orthopaedic Surgery, Chelsea and Westminster Hospital, NHS Foundation Trust, 369 Fulham Road, London, SW10 9NH, UK

5 Orthopädische Klinik der Medizinischen Hochschule Hannover (MHH) im Annastift, Diakoniekrankenhaus Annastift gGmbH, Anna-von-Borries-Str. 1-7, D-30625 Hannover, Germany

6 Department of Traumatology, Clinic for Sports Traumatology, Orthopaedic Surgery and Sports Traumatology, Cologne-Merheim Medical Centre (CMMC), University of Witten/Herdecke (Campus Cologne-Merheim), Ostmerheimerstrasse 200, 51109 Köln, Germany

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BMC Musculoskeletal Disorders 2014, 15:100  doi:10.1186/1471-2474-15-100

Published: 26 March 2014

Abstract

Background

The purpose of this article was to evaluate the risks and benefits of non-operative treatment versus surgical excision of a fabella causing posterolateral knee pain. We performed a systematic review of literature and also present two case reports.

Twelve publications were found in a PubMed literature review searching the word “fabella syndrome”. Non-operative treatment and surgical excision of the fabella has been described.

Case presentation

Two patients presented to our outpatient clinic with persisting posterolateral knee pain. In both cases the presence of a fabella was identified, located in close proximity to the posterolateral femoral condyle. All other common causes of intra- and extra articular pathologies possibly causing the posterolateral knee pain were excluded.

Following failure to respond to physiotherapy both patients underwent arthroscopy which excluded other possible causes for posterolateral knee pain. The decision was made to undertake surgical excision of the fabella in both cases without complication.

Both patients were examined 6 month and one year after surgery with the Tegner activity score, the Visual Analogue Scale (VAS), and International Knee Documentation Committee Score (IKDC).

Conclusion

Consistent posterolateral pain during exercise might indicate the presence of a fabella syndrome. Resecting the fabella can be indicated and is a minor surgical procedure with minimal risk. Despite good results in the literature posterolateral knee pain can persist and prevent return to a high level of sports. Level of evidence: IV, case reports and analysis of literature.

Keywords:
Fabella syndrome; Posterolateral knee pain; Fabellectomy; Sesamoid bone; Return to sports; Review of literature