Longitudinal ultrasound and clinical follow-up of Baker’s cysts injection with steroids in knee osteoarthritis

Abstract

This study was conducted to assess ultrasound (US) and clinical changes of Baker's cyst (BC) of patients with knee osteoarthritis (OA) after steroid injection. Patients with knee OA complicated with symptomatic BC (40) were treated with US-guided direct (posterior) aspiration. The injection of 40 mg triamcynolone acetonide was in 20 patients direct into the BC and in other 20 subjects intra-articular (anterior). BC diameters (longitudinal, transverse, and thickness) were measured and followed up with US at baseline, 2, 4, and 8 weeks after injection. Swelling, pain, and range motion were scored at clinical examination with Rauschning and Lindgren classification (RLC, since 0 normal to 3 maximal signs). All US measures of BC and RLC significantly decreased after treatment, in comparison to baseline (p < 0.001) and during the follow-up, did not change through the time (no significant difference between 2, 4, and 8 weeks). At 4 and 8 weeks, diameters measured at US are lower when BC is directly infiltrated in comparison to intra-articular injection (p < 0.01). US steroid direct injection reduces US measures and clinics of BC in knee OA, in particular, when steroid is directly infiltrated into BC.

The reliability of the clinical examination for detecting Baker's cyst in asymptomatic fossa

“…In patients with arthritis, US is better than physical examination for detecting knee effusion and BCs . Additionally, US‐guided injections and aspirations allow more accurate interventions and quantitative assessment of the treatment response …”

American Medical Society for Sports Medicine (AMSSM) position statement: interventional musculoskeletal ultrasound in sports medicine

“…Most studies evaluated injections into a single structure (42/49 (86%)),17 51 54 69 80 84–87 90–95 97–101 103–113 115–125 but seven studies (14%) investigated injections into more than one structure 52 71 88 89 96 102 114. In decreasing frequency, studies evaluated injections into bursae (19/49 (39%)),17 51 52 54 69 87 91–93 95 97 100 101 103 105 110 115 121 123 tendon sheaths (9/49 (18%)),71 89 102 106 108 111–113 116 tendons or fascia (8/49 {(16%)),96 102 107 112 119 120 124 125 perineural regions (6/49 (12%)),85 88 94 104 109 122 muscles (5/49 (10%)),86 97 114 117 118 cysts (2/49 (4%)),84 90 peritendinous regions (2/49 (4%)),71 102 wounds (1/49 (2%))52 and periarticular spaces (1/49 (2%)) 80…”

Giant Baker’s Cyst Associated with Rheumatoid Arthritis

“…Acebes et al reported successful results following aspiration of cyst contents and KS injection in osteoarthritis related cases [17]. In similar cases, Bandinelli et al also reported successful results using US-guided steroid injection directly into the cyst and intraarticular steroid injection; both methods were considered effective [18]. In the treatment of Baker's cyst accompanied with RA, Hofman-González et al stated that methotrexate application to the cyst may be an alternative method for patients with surgical risk factors [20].…”