Shoulder:Glenohumeral Arthritis/Arthrodesis - Revision history

Peter.gustavsson.2: Gramar correction.

2023-02-23T09:17:21Z

Gramar correction.

Alexandre.laedermann at 06:42, 15 August 2021

2021-08-15T06:42:32Z

Alexandre.laedermann at 06:41, 15 August 2021

2021-08-15T06:41:16Z

Alexandre.laedermann: /* Arthroscopic Glenohumeral Arthrodesis +/- O-arm Navigation */

2021-07-29T14:58:50Z

Arthroscopic Glenohumeral Arthrodesis +/- O-arm Navigation

Alexandre.laedermann: /* Arthroscopic Glenohumeral Arthrodesis +/- O-arm Navigation */

2021-07-29T14:55:35Z

Arthroscopic Glenohumeral Arthrodesis +/- O-arm Navigation

Alexandre.laedermann: /* Arthroscopic Glenohumeral Arthrodesis +/- O-arm Navigation */

2021-07-29T14:52:33Z

Arthroscopic Glenohumeral Arthrodesis +/- O-arm Navigation

Alexandre.laedermann at 14:49, 29 July 2021

2021-07-29T14:49:13Z

Alexandre.laedermann: /* Arthroscopic Glenohumeral Arthrodesis +/- O-arm Navigation */

2021-07-29T14:36:54Z

Arthroscopic Glenohumeral Arthrodesis +/- O-arm Navigation

Alexandre.laedermann: /* Arthroscopic Glenohumeral Arthrodesis +/- O-arm Navigation */

2021-07-29T14:32:45Z

Arthroscopic Glenohumeral Arthrodesis +/- O-arm Navigation

Alexandre.laedermann at 13:53, 29 July 2021

2021-07-29T13:53:34Z

@@ Line 16: / Line 16: @@
 ==Introduction==
-Glenohumeral arthrodesis used to be a favored surgical treatment option for patients with paralysis of the shoulder due to an underlying neurological pathology, massive rotator cuff tears, fracture sequelae, chronic instability, osteoarthritis, rheumatoid arthritis and infection.<ref>Charnley J. Compression arthrodesis of the ankle and shoulder. J Bone Joint Surg Br 1951;33B(2):180-91</ref><ref name=":0">Cofield RH, Briggs BT. Glenohumeral arthrodesis. Operative and long-term functional results. J Bone Joint Surg Am. 1979;61(5):668-77.</ref>
+Glenohumeral arthrodesis used to be a favoured surgical treatment option for patients with paralysis of the shoulder due to an underlying neurological pathology, massive rotator cuff tears, fracture sequelae, chronic instability, osteoarthritis, rheumatoid arthritis and infection.<ref>Charnley J. Compression arthrodesis of the ankle and shoulder. J Bone Joint Surg Br 1951;33B(2):180-91</ref><ref name=":0">Cofield RH, Briggs BT. Glenohumeral arthrodesis. Operative and long-term functional results. J Bone Joint Surg Am. 1979;61(5):668-77.</ref>
 ==Biomechanics==

@@ Line 23: / Line 23: @@
 ===Clinical Practice Guideline===
 The goal of this section is to provide clinicians with recommendations based on the best available evidence; to inform clinicians of when there is no evidence; and finally, to help clinicians deliver the best health care possible.
 ===Conservative (Nonoperative) Treatment===
 ===Operative (Surgical) Treatment===
 Currently, glenohumeral arthrodesis has its place as a rather rare salvage procedure for selected patients with above diagnoses, malignant tumors or failed shoulder arthroplasty.<ref>Atlan F, Durand S, Fox M, Levy P, Belkheyar Z, Oberlin C. Functional outcome of glenohumeral fusion in brachial plexus palsy: a report of 54 cases. J Hand Surg Am. 2012;37(4):683-8.</ref><ref>Chun JM, Byeon HK. Shoulder arthrodesis with a reconstruction plate. Int Orthop. 2009;33(4):1025-30.</ref><ref>Dimmen S, Madsen JE. Long-term outcome of shoulder arthrodesis performed with plate fixation: 18 patients examined after 3-15 years. Acta Orthop. 2007;78(6):827-33.</ref><ref>Hiersemann K, Patsalis T, Saxler G. Arthroscopy-assisted glenohumeral arthrodesis: a case of uncontrollable shoulder instability Unfallchirurg. 2007;110(5):456-9.</ref><ref name=":1">Lädermann A, Denard PJ. Arthroscopic glenohumeral arthrodesis with o-arm navigation. Arthrosc Tech. 2014;3(2):e205-9</ref><ref>Morgan, CD Casscells CD. Arthroscopic-assisted glenohumeral arthrodesis. Arthroscopy. 1992;8(2):262-6</ref><ref>Safran O, Iannotti JP. Arthrodesis of the shoulder. J Am Acad Orthop Surg. 2006;14(3):145-53</ref><ref>Thangarajah T, Alexander S, Bayley I, Lambert SM. Glenohumeral arthrodesis for the treatment of recurrent shoulder instability in epileptic patients. Bone Joint J. 2014;96-B(11):1525-9</ref>
 ===Plate Arthrodesis===

@@ Line 14: / Line 14: @@
 ==Anecdotes[edit | edit source]==
 This subsection does not exist. You can ask for it to be created, but consider checking the search results below to see whether the topic is already covered.
 ==Introduction==
 Glenohumeral arthrodesis used to be a favored surgical treatment option for patients with paralysis of the shoulder due to an underlying neurological pathology, massive rotator cuff tears, fracture sequelae, chronic instability, osteoarthritis, rheumatoid arthritis and infection.<ref>Charnley J. Compression arthrodesis of the ankle and shoulder. J Bone Joint Surg Br 1951;33B(2):180-91</ref><ref name=":0">Cofield RH, Briggs BT. Glenohumeral arthrodesis. Operative and long-term functional results. J Bone Joint Surg Am. 1979;61(5):668-77.</ref>
-<br />
+==Biomechanics==
-==Biomechanics==
+==Treatment==
-==Surgical Indication==
+===Operative (Surgical) Treatment===
 Currently, glenohumeral arthrodesis has its place as a rather rare salvage procedure for selected patients with above diagnoses, malignant tumors or failed shoulder arthroplasty.<ref>Atlan F, Durand S, Fox M, Levy P, Belkheyar Z, Oberlin C. Functional outcome of glenohumeral fusion in brachial plexus palsy: a report of 54 cases. J Hand Surg Am. 2012;37(4):683-8.</ref><ref>Chun JM, Byeon HK. Shoulder arthrodesis with a reconstruction plate. Int Orthop. 2009;33(4):1025-30.</ref><ref>Dimmen S, Madsen JE. Long-term outcome of shoulder arthrodesis performed with plate fixation: 18 patients examined after 3-15 years. Acta Orthop. 2007;78(6):827-33.</ref><ref>Hiersemann K, Patsalis T, Saxler G. Arthroscopy-assisted glenohumeral arthrodesis: a case of uncontrollable shoulder instability Unfallchirurg. 2007;110(5):456-9.</ref><ref name=":1">Lädermann A, Denard PJ. Arthroscopic glenohumeral arthrodesis with o-arm navigation. Arthrosc Tech. 2014;3(2):e205-9</ref><ref>Morgan, CD Casscells CD. Arthroscopic-assisted glenohumeral arthrodesis. Arthroscopy. 1992;8(2):262-6</ref><ref>Safran O, Iannotti JP. Arthrodesis of the shoulder. J Am Acad Orthop Surg. 2006;14(3):145-53</ref><ref>Thangarajah T, Alexander S, Bayley I, Lambert SM. Glenohumeral arthrodesis for the treatment of recurrent shoulder instability in epileptic patients. Bone Joint J. 2014;96-B(11):1525-9</ref>

@@ Line 34: / Line 34: @@
 Under general anesthesia, the patient is placed on a carbon fiber table in the lateral decubitus position, with circumferential access to the right shoulder and the operative arm draped free.<ref name=":1" /> The arm is held with 5 to 10 lb of balanced suspension. A posterior portal is first established. Notably, in cases of severe glenoid retroversion, it is necessary to place this portal from a more medial approach than the typical posterior portal. An anterior portal is then established with an outside-in technique using a spinal needle as a guide. While the surgeon is viewing from the posterior portal and working from the anterior portal, and then vice versa, an electrocautery probe and a 4.5-mm burr are used to lightly denude the articular surfaces of the humeral head to bleeding subchondral bone. In the setting of significant glenoid bone loss, the glenoid is prepared with a curette and microfracture only to avoid further bone loss (Figure, Video). In cases of glenoid bone loss, we do not attempt to achieve fusion between the humeral head and acromion (extra-articular fusion) because superior translation of the humeral head would lead to a loss of contact with the medialized glenoid.
-[[File:3 microfractures.jpg|thumb|center|Right shoulder, anterior viewing portal and posterior working portal. Due to the degree of bone loss, the glenoid is prepared with microfracture only so as to avoid further bone loss. Reproduced with permission from Lädermann et al.,<ref name=":1">Lädermann A, Denard PJ. Arthroscopic glenohumeral arthrodesis with O-arm navigation. Arthrosc Tech. 2014;3(2):e205-9</ref>]]
+[[File:3 microfractures.jpg|thumb|center|Right shoulder, anterior viewing portal and posterior working portal. Due to the degree of bone loss, the glenoid is prepared with microfracture only so as to avoid further bone loss. Reproduced with permission from Lädermann et al.<ref name=":1" />]]
-[[File:Arthrodesis rev-2.mov|thumb|center|The video describes a technique of arthroscopic glenohumeral arthrodesis with O-arm navigation. Indication, installation of the patient, portal placement, preparation of the glenohumeral joint with electrocautery probe and radius burr, positioning of the reference, computer tomography realization and subsequent navigation are reviewed. Reproduced with permission from Lädermann et al.,<ref name=":1">Lädermann A, Denard PJ. Arthroscopic glenohumeral arthrodesis with O-arm navigation. Arthrosc Tech. 2014;3(2):e205-9</ref>]]
+[[File:Arthrodesis rev-2.mov|thumb|center|The video describes a technique of arthroscopic glenohumeral arthrodesis with O-arm navigation. Indication, installation of the patient, portal placement, preparation of the glenohumeral joint with electrocautery probe and radius burr, positioning of the reference, computer tomography realization and subsequent navigation are reviewed. Reproduced with permission from Lädermann et al.<ref name=":1" />]]
 A reference with reflective marker spheres is fixed to the spine of the scapula through a mini-open approach (Figure). A sterile draped O-arm is used to obtain a 3-dimensional computed tomography scan with a medium dose of irradiation, and a computer-assisted navigation system is used (Figure). The shoulder is held in a position of about 30 degrees of flexion, 20 degrees of abduction, and 40 degrees of internal rotation to mimic the previous position of the arm and the desired position for glenohumeral arthrodesis. With the arm held in the appropriate position, 3 to 4 guidewires for 6.5-mm cannulated screws are percutaneously inserted from the humeral head into the glenoid and from the acromion to the humeral head<ref name=":0" /> with the guidance of intraoperative computer-assisted navigation (Figure) and under direct arthroscopic visualization. Anatomic landmarks are used to avoid injury to the neurovascular structures, particularly the axillary nerve laterally. The wires are then measured and reamed for placement of 6.5-mm cannulated cancellous screws. Before tightening of the screws, cancellous allograft bone chips are placed in the glenohumeral joint under arthroscopy with an osteochondral transfer system. In soft humeral cortical bone washers are used to prevent penetration of the screw head into the proximal humerus. The screws are sequentially tightened to achieve adequate compression of the glenohumeral surfaces. The position of each screw is then verified with the O-arm.
-[[File:Diapositive4.jpg|alt=Intraoperative photo of a right shoulder. Prior to O-arm navigation a fixed reference with reflective markers spheres is placed on the spine of the scapula.|thumb|Intraoperative photo of a right shoulder. Prior to O-arm navigation a fixed reference with reflective markers spheres is placed on the spine of the scapula. Reproduced with permission from Lädermann et al.,<ref name=":1">Lädermann A, Denard PJ. Arthroscopic glenohumeral arthrodesis with O-arm navigation. Arthrosc Tech. 2014;3(2):e205-9</ref>]]
+[[File:Diapositive4.jpg|alt=Intraoperative photo of a right shoulder. Prior to O-arm navigation a fixed reference with reflective markers spheres is placed on the spine of the scapula.|thumb|Intraoperative photo of a right shoulder. Prior to O-arm navigation a fixed reference with reflective markers spheres is placed on the spine of the scapula. Reproduced with permission from Lädermann et al.<ref name=":1" />]]
-[[File:Diapositive5.jpg|thumb|Photo demonstrates acquisition of an intraoperative computed tomography scan obtained with an O-arm. The scan is used to to plan the position of the screws. Reproduced with permission from Lädermann et al.,<ref name=":1">Lädermann A, Denard PJ. Arthroscopic glenohumeral arthrodesis with O-arm navigation. Arthrosc Tech. 2014;3(2):e205-9</ref>]]
+[[File:Diapositive5.jpg|thumb|Photo demonstrates acquisition of an intraoperative computed tomography scan obtained with an O-arm. The scan is used to to plan the position of the screws. Reproduced with permission from Lädermann et al.<ref name=":1" />]]
-[[File:Diapositive6.jpg|thumb|Photo demonstrates placement of guide wires in the glenohumeral joint (A) with the guidance of intraoperative computer-assisted navigation (B).Reproduced with permission from Lädermann et al.,<ref name=":1">Lädermann A, Denard PJ. Arthroscopic glenohumeral arthrodesis with O-arm navigation. Arthrosc Tech. 2014;3(2):e205-9</ref>]]
+[[File:Diapositive6.jpg|thumb|Photo demonstrates placement of guide wires in the glenohumeral joint (A) with the guidance of intraoperative computer-assisted navigation (B).Reproduced with permission from Lädermann et al.<ref name=":1" />]]
 <br />

@@ Line 34: / Line 34: @@
 Under general anesthesia, the patient is placed on a carbon fiber table in the lateral decubitus position, with circumferential access to the right shoulder and the operative arm draped free.<ref name=":1" /> The arm is held with 5 to 10 lb of balanced suspension. A posterior portal is first established. Notably, in cases of severe glenoid retroversion, it is necessary to place this portal from a more medial approach than the typical posterior portal. An anterior portal is then established with an outside-in technique using a spinal needle as a guide. While the surgeon is viewing from the posterior portal and working from the anterior portal, and then vice versa, an electrocautery probe and a 4.5-mm burr are used to lightly denude the articular surfaces of the humeral head to bleeding subchondral bone. In the setting of significant glenoid bone loss, the glenoid is prepared with a curette and microfracture only to avoid further bone loss (Figure, Video). In cases of glenoid bone loss, we do not attempt to achieve fusion between the humeral head and acromion (extra-articular fusion) because superior translation of the humeral head would lead to a loss of contact with the medialized glenoid.
-[[File:3 microfractures.jpg|Right shoulder, anterior viewing portal and posterior working portal. Due to the degree of bone loss, the glenoid is prepared with microfracture only so as to avoid further bone loss. Reproduced with permission from Lädermann et al.,<ref name=":1">Lädermann A, Denard PJ. Arthroscopic glenohumeral arthrodesis with O-arm navigation. Arthrosc Tech. 2014;3(2):e205-9</ref>]]
+[[File:3 microfractures.jpg|thumb|center|Right shoulder, anterior viewing portal and posterior working portal. Due to the degree of bone loss, the glenoid is prepared with microfracture only so as to avoid further bone loss. Reproduced with permission from Lädermann et al.,<ref name=":1">Lädermann A, Denard PJ. Arthroscopic glenohumeral arthrodesis with O-arm navigation. Arthrosc Tech. 2014;3(2):e205-9</ref>]]
 [[File:Arthrodesis rev-2.mov|thumb|center|The video describes a technique of arthroscopic glenohumeral arthrodesis with O-arm navigation. Indication, installation of the patient, portal placement, preparation of the glenohumeral joint with electrocautery probe and radius burr, positioning of the reference, computer tomography realization and subsequent navigation are reviewed. Reproduced with permission from Lädermann et al.,<ref name=":1">Lädermann A, Denard PJ. Arthroscopic glenohumeral arthrodesis with O-arm navigation. Arthrosc Tech. 2014;3(2):e205-9</ref>]]

@@ Line 34: / Line 34: @@
 Under general anesthesia, the patient is placed on a carbon fiber table in the lateral decubitus position, with circumferential access to the right shoulder and the operative arm draped free.<ref name=":1" /> The arm is held with 5 to 10 lb of balanced suspension. A posterior portal is first established. Notably, in cases of severe glenoid retroversion, it is necessary to place this portal from a more medial approach than the typical posterior portal. An anterior portal is then established with an outside-in technique using a spinal needle as a guide. While the surgeon is viewing from the posterior portal and working from the anterior portal, and then vice versa, an electrocautery probe and a 4.5-mm burr are used to lightly denude the articular surfaces of the humeral head to bleeding subchondral bone. In the setting of significant glenoid bone loss, the glenoid is prepared with a curette and microfracture only to avoid further bone loss (Figure, Video). In cases of glenoid bone loss, we do not attempt to achieve fusion between the humeral head and acromion (extra-articular fusion) because superior translation of the humeral head would lead to a loss of contact with the medialized glenoid.
-[[File:3 microfractures.jpg|Viewing through anterior portal in right shoulder. Due to the degree of bone loss, microfracture are performed through a posterior portal to avoid further bone loss Reproduced with permission from Lädermann et al.,<ref name=":1">Lädermann A, Denard PJ. Arthroscopic glenohumeral arthrodesis with O-arm navigation. Arthrosc Tech. 2014;3(2):e205-9</ref>|alt=|thumb|858x858px|center]]
+[[File:3 microfractures.jpg|Right shoulder, anterior viewing portal and posterior working portal. Due to the degree of bone loss, the glenoid is prepared with microfracture only so as to avoid further bone loss. Reproduced with permission from Lädermann et al.,<ref name=":1">Lädermann A, Denard PJ. Arthroscopic glenohumeral arthrodesis with O-arm navigation. Arthrosc Tech. 2014;3(2):e205-9</ref>|alt=|thumb|858x858px|center]]
 [[File:Arthrodesis rev-2.mov|thumb|center|The video describes a technique of arthroscopic glenohumeral arthrodesis with O-arm navigation. Indication, installation of the patient, portal placement, preparation of the glenohumeral joint with electrocautery probe and radius burr, positioning of the reference, computer tomography realization and subsequent navigation are reviewed.]]
 A reference with reflective marker spheres is fixed to the spine of the scapula through a mini-open approach (Figure). A sterile draped O-arm is used to obtain a 3-dimensional computed tomography scan with a medium dose of irradiation, and a computer-assisted navigation system is used (Figure). The shoulder is held in a position of about 30 degrees of flexion, 20 degrees of abduction, and 40 degrees of internal rotation to mimic the previous position of the arm and the desired position for glenohumeral arthrodesis. With the arm held in the appropriate position, 3 to 4 guidewires for 6.5-mm cannulated screws are percutaneously inserted from the humeral head into the glenoid and from the acromion to the humeral head<ref name=":0" /> with the guidance of intraoperative computer-assisted navigation (Figure) and under direct arthroscopic visualization. Anatomic landmarks are used to avoid injury to the neurovascular structures, particularly the axillary nerve laterally. The wires are then measured and reamed for placement of 6.5-mm cannulated cancellous screws. Before tightening of the screws, cancellous allograft bone chips are placed in the glenohumeral joint under arthroscopy with an osteochondral transfer system. In soft humeral cortical bone washers are used to prevent penetration of the screw head into the proximal humerus. The screws are sequentially tightened to achieve adequate compression of the glenohumeral surfaces. The position of each screw is then verified with the O-arm.
 [[File:Diapositive4.jpg|alt=Intraoperative photo of a right shoulder. Prior to O-arm navigation a fixed reference with reflective markers spheres is placed on the spine of the scapula.|thumb|Intraoperative photo of a right shoulder. Prior to O-arm navigation a fixed reference with reflective markers spheres is placed on the spine of the scapula.]]
 <br />

← Older revision		Revision as of 14:36, 29 July 2021
Line 39:		Line 39:

	A reference with reflective marker spheres is fixed to the spine of the scapula through a mini-open approach (Figure). A sterile draped O-arm is used to obtain a 3-dimensional computed tomography scan with a medium dose of irradiation, and a computer-assisted navigation system is used (Figure). The shoulder is held in a position of about 30 degrees of flexion, 20 degrees of abduction, and 40 degrees of internal rotation to mimic the previous position of the arm and the desired position for glenohumeral arthrodesis. With the arm held in the appropriate position, 3 to 4 guidewires for 6.5-mm cannulated screws are percutaneously inserted from the humeral head into the glenoid and from the acromion to the humeral head<ref name=":0" /> with the guidance of intraoperative computer-assisted navigation (Figure) and under direct arthroscopic visualization. Anatomic landmarks are used to avoid injury to the neurovascular structures, particularly the axillary nerve laterally. The wires are then measured and reamed for placement of 6.5-mm cannulated cancellous screws. Before tightening of the screws, cancellous allograft bone chips are placed in the glenohumeral joint under arthroscopy with an osteochondral transfer system. In soft humeral cortical bone washers are used to prevent penetration of the screw head into the proximal humerus. The screws are sequentially tightened to achieve adequate compression of the glenohumeral surfaces. The position of each screw is then verified with the O-arm.		A reference with reflective marker spheres is fixed to the spine of the scapula through a mini-open approach (Figure). A sterile draped O-arm is used to obtain a 3-dimensional computed tomography scan with a medium dose of irradiation, and a computer-assisted navigation system is used (Figure). The shoulder is held in a position of about 30 degrees of flexion, 20 degrees of abduction, and 40 degrees of internal rotation to mimic the previous position of the arm and the desired position for glenohumeral arthrodesis. With the arm held in the appropriate position, 3 to 4 guidewires for 6.5-mm cannulated screws are percutaneously inserted from the humeral head into the glenoid and from the acromion to the humeral head<ref name=":0" /> with the guidance of intraoperative computer-assisted navigation (Figure) and under direct arthroscopic visualization. Anatomic landmarks are used to avoid injury to the neurovascular structures, particularly the axillary nerve laterally. The wires are then measured and reamed for placement of 6.5-mm cannulated cancellous screws. Before tightening of the screws, cancellous allograft bone chips are placed in the glenohumeral joint under arthroscopy with an osteochondral transfer system. In soft humeral cortical bone washers are used to prevent penetration of the screw head into the proximal humerus. The screws are sequentially tightened to achieve adequate compression of the glenohumeral surfaces. The position of each screw is then verified with the O-arm.
		+	[[File:Diapositive4.jpg\|alt=Intraoperative photo of a right shoulder. Prior to O-arm navigation a fixed reference with reflective markers spheres is placed on the spine of the scapula.\|thumb\|Intraoperative photo of a right shoulder. Prior to O-arm navigation a fixed reference with reflective markers spheres is placed on the spine of the scapula.]]
		+	<br />

	==Postoperative Rehabilitation==		==Postoperative Rehabilitation==

@@ Line 34: / Line 34: @@
 Under general anesthesia, the patient is placed on a carbon fiber table in the lateral decubitus position, with circumferential access to the right shoulder and the operative arm draped free.<ref name=":1" /> The arm is held with 5 to 10 lb of balanced suspension. A posterior portal is first established. Notably, in cases of severe glenoid retroversion, it is necessary to place this portal from a more medial approach than the typical posterior portal. An anterior portal is then established with an outside-in technique using a spinal needle as a guide. While the surgeon is viewing from the posterior portal and working from the anterior portal, and then vice versa, an electrocautery probe and a 4.5-mm burr are used to lightly denude the articular surfaces of the humeral head to bleeding subchondral bone. In the setting of significant glenoid bone loss, the glenoid is prepared with a curette and microfracture only to avoid further bone loss (Figure, Video). In cases of glenoid bone loss, we do not attempt to achieve fusion between the humeral head and acromion (extra-articular fusion) because superior translation of the humeral head would lead to a loss of contact with the medialized glenoid.
-[[:File:3 microfractures.jpg|Viewing through anterior portal in right shoulder. Due to the degree of bone loss, microfracture are performed through a posterior portal to avoid further bone loss.]]
+[[File:3 microfractures.jpg|Viewing through anterior portal in right shoulder. Due to the degree of bone loss, microfracture are performed through a posterior portal to avoid further bone loss Reproduced with permission from Lädermann et al.,<ref name=":1">Lädermann A, Denard PJ. Arthroscopic glenohumeral arthrodesis with o-arm navigation. Arthrosc Tech. 2014;3(2):e205-9</ref>|alt=|thumb|858x858px|center]]
 A reference with reflective marker spheres is fixed to the spine of the scapula through a mini-open approach (Figure). A sterile draped O-arm is used to obtain a 3-dimensional computed tomography scan with a medium dose of irradiation, and a computer-assisted navigation system is used (Figure). The shoulder is held in a position of about 30 degrees of flexion, 20 degrees of abduction, and 40 degrees of internal rotation to mimic the previous position of the arm and the desired position for glenohumeral arthrodesis. With the arm held in the appropriate position, 3 to 4 guidewires for 6.5-mm cannulated screws are percutaneously inserted from the humeral head into the glenoid and from the acromion to the humeral head<ref name=":0" /> with the guidance of intraoperative computer-assisted navigation (Figure) and under direct arthroscopic visualization. Anatomic landmarks are used to avoid injury to the neurovascular structures, particularly the axillary nerve laterally. The wires are then measured and reamed for placement of 6.5-mm cannulated cancellous screws. Before tightening of the screws, cancellous allograft bone chips are placed in the glenohumeral joint under arthroscopy with an osteochondral transfer system. In soft humeral cortical bone washer are used to prevent penetration of the screw head into the proximal humerus.The screws are sequentially tightened to achieve adequate compression of the glenohumeral surfaces. The position of each screw is then verified with the O-arm.