Effect of USG-guided Baker's Cyst Aspiration
Condition: Baker Cyst; Knee Disease
MeSH terms: Cysts; Popliteal Cyst
Study type: Interventional

Summary: 
      ABSTRACT Objective: The aim of this study was to investigate the effect of ultrasonography
      (USG)-guided Baker's cyst (BC) aspiration in the treatment of BC.

      Design: A total of 40 patients presented to our polyclinic with the complaints of swelling at
      the back of the knee. The 40 patients were randomly divided into two groups: (I) aspiration
      group (n=20) and (II) control group (n=20). In the aspiration group, BC content was aspirated
      percutaneously under USG guidance, whereas no aspiration was performed in the control group.
      Additionally, the participants in both groups were trained on how to perform exercises and
      were also recommended to practice cold treatment for 15 min both in the morning and evening
      for 2 weeks. All the patients were followed up with USG at the first and third months, VAS,
      WOMAC, NHP , Lysholm and Cincinnati. The success of the treatment was demonstrated by the
      decrease in the width, length and area of the BCs and Lysholm, Cincinnati ,VAS, WOMAC and NHP
      scores.
    

Detailed description: 
      Objective: The aim of this study was to investigate the effect of ultrasonography
      (USG)-guided Baker's cyst (BC) aspiration in the treatment of BC.

      Design: This prospective study was conducted at Erzurum Atatürk University Medical Faculty
      Physical Medicine and Rehabilitation Department between January 2016 and June 2017 for a
      total period of 18 months. A total of 40 patients (11 males, 29 females) aged between 33-71
      (mean age, 55.9 ± 9.6) years presented to our polyclinic with the complaints of swelling at
      the back of the knee. All the patients signed an informed consent form and the study was
      approved by the local ethics committee. (ERZURUM ATATUK UNIVERSITY MEDICAL FACULTY CLINICAL
      RESEARCH ETHICS COMMITTEE Date:03.12.2015 Meeting Number:8 Decision Number:24) Patients with
      a history of malignancy, coagulation disorder, and a neurological deficit and those receiving
      anticoagulant therapy were excluded from the study. The sample size was determined with a 95%
      confidence interval according to https://www.macorr.com/sample-size-calculator.htm website.

      Prior to the procedure, all the patients were evaluated with grey-scale USG using an Esaote
      MyLab 60 USG device with a linear probe of 7.5 MHz. On USG examination, the area of
      transverse diameter(width-parallel to the knee joint), longitudinal diameter
      (length-perpendicular to the knee joint), and the USG area( from the widest place viewed) of
      BCs were calculated and recorded.

      Clinical complaints of the patients, long-term complaints, and the history of medical,
      interventional, and surgical treatments were reviewed for each patient. Patients were also
      investigated for acute local or systemic infections.

      The severity of clinical complaints was assessed using VAS, WOMAC knee osteoarthritis index,
      Lysholm knee scoring scale, Cincinnati knee rating system, and NHP. Patients with BC who had
      no contraindications for treatment and completed the WOMAC Knee osteoarthritis index, Lysholm
      knee scoring scale, Cincinnati knee rating system, VAS, and NHP and signed the patient
      consent form were included in the study. Patients were randomly divided into two groups by
      consecutive alternate allocation according to the time of admittance: (I) aspiration group
      (n=20) included the patients aspirated and (II) control group (n=20) included those who did
      not aspirated. In the aspirated group, the popliteal fossa areas were sterilized and BC
      content was aspirated from the popliteal fossa percutaneously under USG guidance with a
      21-gauge needle (Figure 1). If the BC was septal, aspiration was performed from several
      different levels of the cyst so that the cyst content could be completely emptied. In
      contrast, no aspiration was performed in the control group. Additionally, the participants in
      both groups were trained on how to perform exercises and were also recommended to practice
      cold treatment for 15 min both in the morning and evening for 2 weeks.

      After the aspiration, the patients were told how to exercise and practice cold treatment in
      the morning and evening for 2 weeks. Patients were discharged after a 30-min observation
      period following the procedure. Patients were allowed to apply bandages for 2 days after the
      procedure and were followed pre- and post-procedurally at the first and third months of
      treatment with WOMAC Knee osteoarthritis index, Lysholm knee scoring scale, Cincinnati knee
      rating system, VAS, and NHP and with USG. The appearance of BC at month 3 was examined on
      grey-scale USG and the length, width, and area of the cyst were recalculated. During the
      3-month follow-up period, no additional treatment was performed in any patient. The success
      of the procedure was defined as reduction in BC width, length and area in sonographic
      measurements and decrease in the Lysholm knee scoring scale, Cincinnati knee rating system,
      VAS, WOMAC knee osteoarthritis index, and NHP scores.
    

Intervention name(s): interventional
Intervention type(s): Procedure
Intervention description(s): In the aspirated group, the popliteal fossa areas were sterilized and BC content was aspirated from the popliteal fossa percutaneously under USG guidance with a 21-gauge needle (Figure 1). If the BC was septal, aspiration was performed from several different levels of the cyst so that the cyst content could be completely emptied.
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Baker's cyst; Ultrasonography,; Cyst aspiration; Knee exercises for Baker's cyst; Cold pack