Arthroscopic Interpositional Arthroplasty of the Second Metatarsophalangeal Joint  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 e1333-e1338 (December 2016) DOI: 10.1016/j.eats.2016.08.008 Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

Fig 1 Arthroscopic interpositional arthroplasty of right second metatarsophalangeal joint. Second metatarsophalangeal arthroscopy is performed through the dorsomedial portal (DMP) and dorsolateral portal (DLP). The DMP and DLP are located at the second metatarsophalangeal joint level, medial and lateral to the extensor tendons, respectively. The DLP is the viewing portal, and the DMP is the working portal. Arthroscopy Techniques 2016 5, e1333-e1338DOI: (10.1016/j.eats.2016.08.008) Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

Fig 2 Arthroscopic interpositional arthroplasty of right second metatarsophalangeal joint. The dorsolateral portal is the viewing portal, and the dorsomedial portal is the working portal. Arthroscopic view shows the large chondral defect (CD) at the metatarsal head (MT). (AS, arthroscopic shaver.) Arthroscopy Techniques 2016 5, e1333-e1338DOI: (10.1016/j.eats.2016.08.008) Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

Fig 3 Arthroscopic interpositional arthroplasty of right second metatarsophalangeal joint. The dorsolateral portal is the viewing portal, and the dorsomedial portal is the working portal. Arthroscopic view shows synovitis at the medial side of the joint. (AS, arthroscopic shaver; MT, metatarsal head; S, inflamed synovium.) Arthroscopy Techniques 2016 5, e1333-e1338DOI: (10.1016/j.eats.2016.08.008) Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

Fig 4 Arthroscopic interpositional arthroplasty of right second metatarsophalangeal joint. (A) The extensor digitorum brevis (EDB) tendon is identified at the dorsolateral portal (DLP) and the proximal incision. (B) The EDB tendon is cut at the proximal incision and is retrieved to the DLP. (C) The tendon graft is rolled and sutured with long stay suture. Arthroscopy Techniques 2016 5, e1333-e1338DOI: (10.1016/j.eats.2016.08.008) Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

Fig 5 Arthroscopic interpositional arthroplasty of right second metatarsophalangeal joint. The dorsomedial portal (DMP) is the viewing portal, and the dorsolateral portal (DLP) is the working portal. (A) The straight eyed needle loaded with the stay suture of the extensor digitorum brevis (EDB) tendon graft is inserted through the DLP. (B) The needle (N) passes over the center of the chondral defect of the metatarsal head (MT) and pierces through the plantar plate (PP). Arthroscopy Techniques 2016 5, e1333-e1338DOI: (10.1016/j.eats.2016.08.008) Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

Fig 6 Arthroscopic interpositional arthroplasty of right second metatarsophalangeal joint. The dorsomedial portal is the viewing portal, and the dorsolateral portal is the working portal. The extensor digitorum brevis (EDB) tendon ball is seated on the chondral defect of the metatarsal head (MT). The stay suture (SS) of the tendon passes through the plantar plate (PP). Arthroscopy Techniques 2016 5, e1333-e1338DOI: (10.1016/j.eats.2016.08.008) Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

Fig 7 Arthroscopic interpositional arthroplasty of right second metatarsophalangeal joint. (A) The exit point of the stay suture at the plantar skin is dilated by the tip of a hemostat. (B) The suture is tied and stabilizes the extensor digitorum brevis tendon ball by forming a bulky knot on the surface of the fibrous tendon sheath. (PEP, plantar exit point.) Arthroscopy Techniques 2016 5, e1333-e1338DOI: (10.1016/j.eats.2016.08.008) Copyright © 2016 Arthroscopy Association of North America Terms and Conditions