Arthroscopic Excision of Osteoid Osteoma of the Elbow Deepak N. Bhatia, M.S.(Orth.), D.N.B.(Orth.)  Arthroscopy Techniques  Volume 6, Issue 3, Pages e543-e548 (June 2017) DOI: 10.1016/j.eats.2016.11.014 Copyright © 2017 Arthroscopy Association of North America Terms and Conditions

Fig 1 (A) Magnetic resonance imaging of the left elbow shows a well-defined lytic lesion (0.5 × 0.5 × 0.7 cm) in the lower end of the humerus. The lesion (OS) is lateral to the coronoid fossa and is proximal to the articular margin of the capitellum (right image, coronal image). The overlying anterior cortex is thin (black arrow, left image axial view), and the associated synovitis (SY) is noted. (B) Computed tomographic scan of the left elbow shows a central lytic zone surrounded by a peripheral sclerotic rim in the lower end of the humerus (right image, coronal view). The overlying anterior cortex is thinned out (white arrow, central image axial view), and a probably osseous reactive tissue is noted proximal to the lesion (white arrow, left image, sagittal view). (A, anterior; C, capitellum; E, lateral epicondyle; L, lateral; LE, lateral epicondyle; M, medial; ME, medial epicondyle; OL, olecranon; P, posterior; R, radial head; T, trochlea; U, proximal ulna.) Arthroscopy Techniques 2017 6, e543-e548DOI: (10.1016/j.eats.2016.11.014) Copyright © 2017 Arthroscopy Association of North America Terms and Conditions

Fig 2 Elbow position and portals used in the technique are shown (left elbow, lateral decubitus position). A standard anterolateral portal (AL) is created approximately 1 cm proximal and anterior to the lateral epicondyle (LE). An accessory anterolateral portal (AC) is created approximately 1 cm anterior and directly lateral to the lateral epicondyle. An old surgical scar (dotted line) from a previous open surgery is seen along the lateral aspect of the elbow. (INF, inferior; LAT, lateral; MED, medial; OL, olecranon; R, radial head, SUP, superior.) Arthroscopy Techniques 2017 6, e543-e548DOI: (10.1016/j.eats.2016.11.014) Copyright © 2017 Arthroscopy Association of North America Terms and Conditions

Fig 3 Arthroscopic image of the left elbow is shown via a 30° view (anteromedial portal). A thorough adhesiolysis is performed to visualize the radial head (R) and capitellum (C). An accessory anterolateral portal (AC) is made using an outside-in technique via a needle and is used to access the scar tissue (ST, white arrows) overlying the osteoid osteoma. (INF, inferior; LAT, lateral; MED, medial; SUP, superior.) Arthroscopy Techniques 2017 6, e543-e548DOI: (10.1016/j.eats.2016.11.014) Copyright © 2017 Arthroscopy Association of North America Terms and Conditions

Fig 4 Arthroscopic image of the left elbow is shown via a 70° view (anteromedial portal). A shaver blade (SH) is introduced via the accessory anterolateral portal (AC) and is used to debride the thick scar tissue (ST) overlying the osteoid osteoma (OS). (INF, inferior; LAT, lateral; MED, medial; SUP, superior; TR, trochlear articular margin.) Arthroscopy Techniques 2017 6, e543-e548DOI: (10.1016/j.eats.2016.11.014) Copyright © 2017 Arthroscopy Association of North America Terms and Conditions

Fig 5 Arthroscopic appearance of an osteoid osteoma (left elbow) is shown via a 70° view (anteromedial portal). The right image shows a purplish central region of soft trabecular bone (white arrow), and this is surrounded by a peripheral zone of dense sclerotic bone (black arrows). The left image shows the deeper region of the lesion and is seen after obtaining a biopsy. The deeper aspect shows red discoloration and oozing from bleeding bone (white arrows), and the surrounding rim (black arrows) appears avascular. (INF, inferior; LAT, lateral; MED, medial; SUP, superior.) Arthroscopy Techniques 2017 6, e543-e548DOI: (10.1016/j.eats.2016.11.014) Copyright © 2017 Arthroscopy Association of North America Terms and Conditions

Fig 6 Arthroscopic technique of obtaining a biopsy is shown (left elbow) via a 70° view (anteromedial portal). An angled biter is used via the accessory anterolateral portal and provides access to the distal lateral humerus. The upper jaw (PU) is inserted deep into the osteoid osteoma (OS), and the jaws are closed to obtain a chunk of tissue under direct visualization. (INF, inferior; LAT, lateral; MED, medial; SUP, superior.) Arthroscopy Techniques 2017 6, e543-e548DOI: (10.1016/j.eats.2016.11.014) Copyright © 2017 Arthroscopy Association of North America Terms and Conditions

Fig 7 Arthroscopic technique of excision and curettage of an osteoid osteoma (left elbow) is shown via a 70° view (anteromedial portal). (A) An angled chisel (CH) is used via the accessory anterolateral portal and provides access to deeper region of the lesion (OS). The angled tip reaches proximal to the articular margins of the capitellum (C) and trochlea (TR). An angled biter is used in conjunction, and the lesion is excised piecemeal. (B) A ring curette (CU) is used to further excise the peripheral sclerotic region of the lesion (OS). (C) The debris and bone flakes from the lesion and finally debrided using an angled shaver blade (SH). (INF, inferior; LAT, lateral; MED, medial; SUP, superior.) Arthroscopy Techniques 2017 6, e543-e548DOI: (10.1016/j.eats.2016.11.014) Copyright © 2017 Arthroscopy Association of North America Terms and Conditions

Fig 8 (A) Arthroscopic step of radiofrequency ablation of the osteoid osteoma (left elbow) is shown via a 70° view (anteromedial portal). A radiofrequency probe (RF) is passed via the accessory anterolateral portal (AC), and the 90° angled tip is approximated to the lesion. (B) Ablation is performed in short pulses for approximately 5-10 minutes. Note that the depth of the lesion is sufficiently ablated; the reddish bleeding tissue is no longer visible (white arrows), and the peripheral sclerotic bone is excised (black arrows). (INF, inferior; LAT, lateral; MED, medial; SUP, superior.) Arthroscopy Techniques 2017 6, e543-e548DOI: (10.1016/j.eats.2016.11.014) Copyright © 2017 Arthroscopy Association of North America Terms and Conditions