Flexor Hallucis Longus Tenosynovitis and First Metatarsophalangeal Synovitis After Penetrating Nail Prick Injury: Treated by Zone 3 Flexor Hallucis Longus Tendoscopy and Metatarsosesamoid Arthroscopy  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 6, Issue 2, Pages e427-e433 (April 2017) DOI: 10.1016/j.eats.2016.10.020 Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

Fig 1 Flexor hallucis tenosynovitis and first metatarsophalangeal synovitis of the right foot after penetrating nail prick injury: treated by zone 3 flexor hallucis longus (FHL) tendoscopy and metatarsosesamoid arthroscopy. Computed tomogram of the illustrated case. The coronal view shows soft tissue swelling around the first metatarsal head and FHL tendon. The lateral sesamoid bone (LS) is partially destructed. Arthroscopy Techniques 2017 6, e427-e433DOI: (10.1016/j.eats.2016.10.020) Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

Fig 2 Flexor hallucis tenosynovitis and first metatarsophalangeal synovitis of the right foot after penetrating nail prick injury: treated by zone 3 flexor hallucis longus (FHL) tendoscopy and metatarsosesamoid arthroscopy. The patient is in the supine position with the legs spread. Zone 3 FHL tendoscopy is performed through the proximal and distal portals along the FHL tendon. (A) The distal portal (DP) is located just proximal to the hallux interphalangeal joint (IPJ). (B) A 2.7-mm Wissinger rod (WR) is inserted into the tendon sheath and advanced proximally. The rod penetrates through the plantar aponeurosis at the level of the Lisfranc joint. A 3- to 4-mm longitudinal incision is made at the tip of the rod to establish the proximal portal (PP). The rod then passes through both the proximal and distal portals. An arthroscopic cannula (AC) is inserted into the proximal portal along the Wissinger rod. (C) The rod is removed and the arthroscope is inserted into the cannula. An arthroscopic shaver is inserted via the distal portal. (D) Arthroscopic view with the proximal portal as the viewing portal. (AS, arthroscopic shaver; C, plantar capsule of the first metatarsophalangeal joint; LS, lateral sesamoid bone; MT, plantar side of the first metatarsal head seen through the perforated plantar capsule.) Arthroscopy Techniques 2017 6, e427-e433DOI: (10.1016/j.eats.2016.10.020) Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

Fig 3 Flexor hallucis tenosynovitis and first metatarsophalangeal synovitis of the right foot after penetrating nail prick injury: treated by zone 3 flexor hallucis longus (FHL) tendoscopy and metatarsosesamoid arthroscopy. The patient is in the supine position with the legs spread. (A) The Wissinger rod passes through both portals and the arthroscope cannula is inserted along the rod via the distal portal. (B) The cannula passes through both portals and the rod is removed. The arthroscope is inserted half way into the cannula via the distal portal. The arthroscopic shaver is inserted into the cannula via the proximal portal. (C) Keeping the arthroscope and arthroscopic shaver in position, the cannula is retrieved backward and incorporated into the arthroscope. This manoeuvre can ensure the correct positioning of the shaver. (D) Distal portal is the viewing portal. The inflamed tissue adjacent to the FHL tendon is resected endoscopically. (AC, arthroscope cannula; Ar, arthroscope; AS, arthroscopic shaver; DP, distal portal; IPJ, hallux interphalangeal joint; IT, inflamed tissue; PP, proximal portal; WR, Wissinger rod.) Arthroscopy Techniques 2017 6, e427-e433DOI: (10.1016/j.eats.2016.10.020) Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

Fig 4 Flexor hallucis tenosynovitis and first metatarsophalangeal synovitis of the right foot after penetrating nail prick injury: treated by zone 3 flexor hallucis longus tendoscopy and metatarsosesamoid arthroscopy. The patient is in the supine position with the legs spread. (A) The proximal medial portal (PMP) is the viewing portal and the medial portal (MP) is the working portal. (B) Arthroscopic view showed inflamed synovium (IS) at the metatarsosesamoid compartment. (MT, first metatarsal head.) Arthroscopy Techniques 2017 6, e427-e433DOI: (10.1016/j.eats.2016.10.020) Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

Fig 5 Flexor hallucis tenosynovitis and first metatarsophalangeal synovitis of the right foot after penetrating nail prick injury: treated by zone 3 FHL tendoscopy and metatarsosesamoid arthroscopy. The patient is in the supine position with the legs spread. (A) The medial portal (MP) is the viewing portal and the proximal medial portal (PMP) is the working portal. (B) Arthroscopic view showed inflamed synovium (IS) at the metatarsosesamoid compartment. (AS, arthroscopic shaver; LS, lateral sesamoid bone; MT, first metatarsal head.) Arthroscopy Techniques 2017 6, e427-e433DOI: (10.1016/j.eats.2016.10.020) Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

Fig 6 Flexor hallucis tenosynovitis and first metatarsophalangeal synovitis of the right foot after penetrating nail prick injury: treated by zone 3 flexor hallucis longus tendoscopy and metatarsosesamoid arthroscopy. The patient is in the supine position with the legs spread. (A) Arthroscopic synovectomy of the dorsal capsular recess of the metatarsophalangeal compartment with the medial portal (MP) as the viewing portal and the dorsolateral portal (DLP) as the working portal. (B) Arthroscopic synovectomy of the medial capsular recess of the metatarsophalangeal compartment with the DLP as the viewing portal and the MP as the working portal. (C) Arthroscopic synovectomy of the lateral capsular recess of the metatarsophalangeal compartment with the MP as the viewing portal and the DLP as the working portal. Arthroscopy Techniques 2017 6, e427-e433DOI: (10.1016/j.eats.2016.10.020) Copyright © 2016 Arthroscopy Association of North America Terms and Conditions