Baker's cyst

Classification according to ICD-10
M71.2	Synovial cyst in the hollow of the knee (Baker's cyst)
M66.0	Popliteal cyst rupture
ICD-10 online (WHO version 2019)

The popliteal cyst (popliteal: belonging to the hollow of the knee) of the rheumatoid patient was originally called the Baker cyst . Today, however, the term is mostly used as a synonym for all popliteal cysts, regardless of their origin . It is a protuberance of the dorsal joint capsule on the knee joint between the gastrocnemius muscle (medial head) and the semimembranosus muscle . They usually arises in connection with a damage within the knee joint, such as a lesion of the medial meniscus , an osteoarthritic cartilage change or a rheumatoid arthritis . By chronic inflammation leads to an increased production of synovial fluid , creating a positive pressure in the knee joint is formed. The joint capsule then indicates the above at the location of the least resistance ( Locus minoris resistentiae ). Adjust and form a cyst .

First describer

William Morrant Baker (1839-1896), surgeon, London.

Symptoms

Swelling, fluctuation and possibly pain in the hollow of the knee. Pressure on nerves and vessels in the hollow of the knee. This can cause numbness, paralysis and circulatory disorders in the area of ​​the lower leg and foot. There is an increased likelihood of developing in connection with an underlying rheumatic disease. Baker's cyst can cause complications. If the pressure is too strong, it can tear and cause a compartment syndrome .

diagnosis

In addition to the clinical manual examination, the diagnosis is confirmed by ultrasound ( sonography ) and possibly magnetic resonance imaging ; there are also differential diagnoses , such as aneurysms of the popliteal artery or vein excluded.

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  Baker's cyst sagittal on magnetic resonance imaging . Connection to the joint not shown.

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  Baker's cyst on the MRI sagittal with the point of passage to the joint (arrow) between the M. semimembranosus and M. gastrocnemius caput mediale.

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  Baker's cyst (MRI) axial with penetration point (arrow) between M. semimembranosus and M. gastrocnemius caput mediale.

therapy

Surgical removal ( resection ) only rarely makes sense, since the Baker cyst is caused by an effusion in the knee joint. A causal therapy for Baker's cyst starts in the knee joint. If the damage in the joint is repaired, the cyst can regress. Otherwise there is a relatively high probability that the Baker cyst will recur after its removal ( relapse ). Like any operation, the operation carries a certain risk of infection.

In addition, the cyst can normally also in an accident or orthopedic surgeons through a puncture treated or removed.

Individual evidence

1. ^ M. Baker: The formation of abnormal synovial cysts in connection with the joints . In: St. Bartholomew's Hospital Reports . No. 21 . London 1885, p. 177-190 ( online ).
2. ^ W. Pschyrembel: Clinical dictionary. 258th edition. de Gruyter.
3. ↑ Hh Keo, Sb Gretener: Unexpected things in the popliteal fossa . In: Swiss Medical Forum - Swiss Medical Forum . tape 9 , no. 03 , 14 January 2009, ISSN  1424-4020 , doi : 10.4414 / smf.2009.06717 ( emh.ch [accessed on 15 July 2020]).
4. ↑ Stoller, Tirman. Diagnostic Imaging Orthopedics. Elsevier, Amyrsis

This article is about a health issue. It is not used for self-diagnosis and does not replace a diagnosis by a doctor. Please note the information on health issues !