1. Endoscopic Removal of Loose Bodies of the Posterior Ankle Extra-articular Space Arising From Flexor Hallucis Longus Tenosynovial Osteochondromatosis 
Tun Hing Lui, M.B.B.S.(HK), F.R.C.S.(Edin), F.H.K.A.M., F.H.K.C.O.S. 
Arthroscopy Techniques 
Volume 5, Issue 6, Pages e1247-e1252 (December 2016)
DOI: /j.eats
Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

2. Fig 1
Endoscopic removal of loose bodies from right posterior ankle extra-articular space. (A) A preoperative lateral ankle radiograph of the presented case shows multiple loose bodies (arrowheads) of the posterior ankle. (B-D) Sagittal views on preoperative magnetic resonance imaging show loose bodies (arrowheads) at the synovial pouch adjacent to the flexor hallucis longus muscle (B), posterior ankle extra-articular space proper (C), and medial wall of the posterior ankle (D). (A, anterior; P, posterior.)
Arthroscopy Techniques 2016 5, e1247-e1252DOI: ( /j.eats )
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3. Fig 2
Endoscopic removal of loose bodies from right posterior ankle extra-articular space. The patient is in the prone position. Posterior ankle endoscopy is performed through the posteromedial portal (PMP) and posterolateral portal (PLP).
Arthroscopy Techniques 2016 5, e1247-e1252DOI: ( /j.eats )
Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

4. Fig 3
Endoscopic removal of loose bodies from right posterior ankle extra-articular space. The posterolateral portal (PLP) is the viewing portal. (A) A large loose body (LB) is shown in the posterior ankle extra-articular space proper (EAS). (B) The loose body is removed by a hemostat through the posteromedial portal (PMP).
Arthroscopy Techniques 2016 5, e1247-e1252DOI: ( /j.eats )
Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

5. Fig 4
Endoscopic removal of loose bodies from right posterior ankle extra-articular space. The posterolateral portal is the viewing portal. A loose body (LB) is found at the medial wall of the posterior ankle and is posterior to the tibial neurovascular bundle (TNVB).
Arthroscopy Techniques 2016 5, e1247-e1252DOI: ( /j.eats )
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6. Fig 5
Endoscopic removal of loose bodies from right posterior ankle extra-articular space. The posterolateral portal is the viewing portal. A loose body (LB) of the posteromedial ankle gutter is enucleated by an arthroscopic shaver through the posteromedial portal. (FHL, flexor hallucis longus tendon.)
Arthroscopy Techniques 2016 5, e1247-e1252DOI: ( /j.eats )
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7. Fig 6
Endoscopic removal of loose bodies from right posterior ankle extra-articular space. The posterolateral portal is the viewing portal. Loose bodies (LB) are found in the synovial pouch lateral to the flexor hallucis longus muscle (FHLm).
Arthroscopy Techniques 2016 5, e1247-e1252DOI: ( /j.eats )
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8. Fig 7
Endoscopic removal of loose bodies from right posterior ankle extra-articular space. The posterolateral portal is the viewing portal. Budding (B) from the inflamed synovium (S) is found around the flexor hallucis longus tendon (FHL).
Arthroscopy Techniques 2016 5, e1247-e1252DOI: ( /j.eats )
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9. Fig 8
Endoscopic removal of loose bodies from right posterior ankle extra-articular space. Zone 2 flexor hallucis longus tendoscopy is performed. (A) A Wissinger rod is inserted into the flexor hallucis longus tendon sheath under the sustentaculum tali through the posteromedial portal. (B) The arthroscope cannula is inserted along the rod. (PMP, posteromedial portal.) (C) The rod is exchanged with an arthroscope. (D) An arthroscopic view of the zone 2 flexor hallucis longus (FHL) tendon sheath shows no tenosynovitis or loose bodies.
Arthroscopy Techniques 2016 5, e1247-e1252DOI: ( /j.eats )
Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

10. Fig 9
Endoscopic removal of loose bodies from right posterior ankle extra-articular space. (A) Loose bodies removed from posterior ankle extra-articular space in presented case. (B) A postoperative lateral ankle radiograph shows that the posterior ankle was free of loose bodies.
Arthroscopy Techniques 2016 5, e1247-e1252DOI: ( /j.eats )
Copyright © 2016 Arthroscopy Association of North America Terms and Conditions