K.E.M. Radiology
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Seth G.S. Medical College and K.E.M. Hospital, Mumbai , India
Interventional Case Record
Contributed by : Anjali Methre
Genicular artery embolization for knee pain in a patient with osteoarthritis : A novel technique
Introduction:
Osteoarthritis of the knee is one of the leading causes of knee pain and disability in adults, with a prevalence as high as 28 % in the Indian population [1]. Most patients with mild to moderate symptoms are treated with non-steroidal anti-inflammatory drugs and physiotherapy, with knee arthroplasty generally reserved for severe cases. Surgical intervention is an established technique for end-stage osteoarthritis. However, patients with mild to moderate osteoarthritis may not be ideal surgical candidates due to associated co-morbidities or low disease severity, and pain-relief in these patients may be a challenge [2].
Genicular artery embolization (GAE) is a recently advocated treatment modality for osteoarthritis, which involves selective cannulation of the abnormal genicular arteries by endovascular approach followed by embolized using particulate materials to reduce the hypervascularity of an osteoarthritic knee joint. [5,6].
Case presentation:
A 51-year-old woman presented with complaint of pain in both knee joints (R>L) for two years more on medial aspect of right knee joint.The pain was insidious in onset, gradually progressive in nature and aggravated during activity. There was joint effusion and stiffness. The patient had been conservatively managed with NSAIDS (Oral and injectables).
On examination. there is swelling and tenderness over medial aspect of right knee. Her blood parameters were within normal limits.
Radiological findings:
The frontal and lateral radiographs of the knee joint show narrowing of the medial joint space with subchondral sclerosis and marginal osteophytes. There are a few subchondral cysts. (Kellgren and Lawrence classification grade III). (Figure 1)
Fig 1:
Radiograph of right knee standing AP and Lateral view showing Grade III Kellgren and Lawrence classification - medial joint space loss, osteophytosis and subchondral sclerosis.
The patient was managed conservatively with NSAIDS (Oral and injectables) but there was no relief of symptoms. Owing to the young age surgical management was not offered and she was referred to interventional radiology for genicular artery embolization. Her pre procedure WOMAC score was 47 and VAS pain score was 7.
Interventional technique:
The left common femoral artery access was used. We started with a cobra catheter and exchanged it for a H! catheter. It was advanced upto the right mid third segment of superficial femoral artery. The DSA showed synovial enhancement on right medial joint space with supply from right descending genicular artery and right branch of sural artery. (Figure 2a and 2b) . Color coded demonstration of arterial anatomy over the DSA angiogram image is shown below (figure 2c)
Figure 2a and 2b- DSA angiogram of right superficial femoral artery and popliteal artery with 4F H1 catheter from distal third segment demonstrate prominent descending genicular artery and branch of sural artery.
Figure 2c- Colour coded DSA anatomical angiogram demonstrating images showing- descending genicular artery (yellow), superior medial genicular artery (green), superior lateral genicular artery (blue) and branch of sural artery (violet).
Following this, super selective cannulation of right descending genicular artery was done and angiogram was taken showing synovial enhancement on medial joint space. (figure 3a). We have applied ice pack over the knee joint region prior to embolization to prevent skin region ischemic phenomenon. Particle embolization was done using 100-micron embosphere particle mixed with contrast. Post embolization angiogram shows no evidence of any synovial enhancement on medial side of joint space. (figure 3b)
Figure 3a- Super selective angiogram of the right descending genicular artery using microcatheter showing synovial enhancement on the medial side.
Figure 3b- Post embolization super selective angiogram of the right descending genicular artery using microcatheter showing no synovial enhancement on the medial side.
Similarly, super selective catherisation of the right branch of the sural artery was performed. The angiogram showed synovial enhancement in the medial joint space. (figure 4a). We applied ice pack over the knee joint region prior to embolization to prevent skin ischemia Particle embolization was done using 100-micron embosphere particle mixed with contrast. Post embolization angiogram shows no synovial enhancement on the medial side of the joint space. (figure 4b)
Figure 4a- Super selective angiogram of branch of sural artery using microcatheter showing synovial enhancement on medial side.
Figure 4b- post embolization super selective angiogram of branch of sural artery using microcatheter showing no evidence of any synovial enhancement on medial side.
Post embolization angiogram showed resolution of synovial enhancement of the medial joint space. (figure 5). The post procedure day 1, 1 week and 1 month WOMAC score were respectively 44, 40 and 38. Similarity post procedure day 1, 1 week and 1c month VAS score were 6, 4 and 3 respectively.
Fig 5
Figure 5- DSA Angiogram after particle embolization obtained with 4F H1 catheter from distal third segment demonstrating reduced synovial enhancement on medial side.
Discussion:
Earlier considered a degenerative disease, the pathophysiology and disease progression of osteoarthritis are now considered to be multifactorial, with inflammation being an important factor for joint pain and disease progression. Multiple inflammatory mediators, such as interleukins, growth factors, nitric oxide, prostaglandins, and complement factors, have been associated with chronic synovitis. This leads to synovial neoangiogenesis, which in turn contributes to osteophyte formation, cartilage destruction, and a painful knee [3, 4].
In osteoarthritis, the medial joint compartment involvement is 5 to 10 times more common than the lateral. Therefore, the medial and descending genicular arteries are the more common targets for embolization procedures. It is important to know the blood supply of the knee joint and the exact artery supplying the region of blush. The middle genicular artery is the main supply to the anterior and posterior cruciate ligaments. The inferomedial and lateral genicular artery provide vascularization to the patella (Figure 6a).
The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score is used for analyzing the progress of osteoarthritis and accessing post-treatment response (Figure 6b).
Figure 6a- Anatomy of knee joint blood supply.
Figure 6b- The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scoring table.