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Endoscopic Excision of Supracondylar Humeral Spur for Decompression of the Median Nerve and Brachial Artery
Endoscopic Excision of Supracondylar Humeral Spur for Decompression of the Median Nerve and Brachial Artery Gregory Bain, F.R.A.C.S., Ph.D., Prince Gupta, M.S., Joideep Phadnis, F.R.C.S., and Prahalad K. Singhi, D.N.B.
Abstract: The humeral supracondylar process and Struthers ligament comprise a relatively rare but well-known anatomic variant. They are usually asymptomatic but may produce clinical symptoms related to compression of the median nerve or brachial artery below the ligament. Previously, surgery has been performed with an open ligament release and supracondylar process excision. This article reports on the use of endoscopic findings and the method of ligament release and process excision. Endoscopy is a minimally invasive technique that provides excellent visualization and enables the surgeon to perform dissection with magnification and precision. It allows the surgeon to introduce open surgical techniques into the depths of the wound in a controlled manner. Because of the dead space created, there is a risk of hematoma formation. Many of the concepts used in open surgery are now being used for endoscopic surgery, and vice versa. The barriers and differences among endoscopic, arthroscopic, and open procedures are being broken down. We report another endoscopic technique, which is part of the ongoing evolution of musculoskeletal surgery.
T
he supracondylar spur or process was noted by Tiedmann1 in 1818 and described further by Struthers in 18482 as a bony projection on the anteromedial humerus approximately 5 cm proximal to the medial epicondyle. It occurs in 0.4% to 2.7% of the worldwide population.3 The supracondylar process is a normal anatomic variant that represents the embryologic vestigial remnant of the latissimo-condyloideus, a muscle that is still present in climbing animals, many reptiles, and cats. In humans this muscle is usually represented as a fibrous band between the tendons of the latissimus dorsi and coracobrachialis.3 The bone formation starts from a broad base, about 7 cm
From the Department of Orthopaedic Surgery, Flinders University (G.B., P.G., J.P., P.K.S.), Adelaide, Australia; Department of Orthopaedic Surgery, Flinders Medical Centre (G.B., P.G., J.P., P.K.S.), Adelaide, Australia; International Musculoskeletal Research Institute (G.B., P.G., J.P., P.K.S.), Adelaide, Australia; and Alchemist Hospital (P.G.), Gurgaon, India. The authors report that they have no conflicts of interest in the authorship and publication of this article. Received June 20, 2015; accepted August 28, 2015. Address correspondence to Prince Gupta, House No. 172, Sector 12 a, Gurgaon 122001, Haryana, India. E-mail: [email protected] Ó 2016 Arthroscopy Association of North America. Published by Elsevier. All rights reserved 2212-6287/15564/$36.00 http://dx.doi.org/10.1016/j.eats.2015.08.019
proximal to the medial epicondyle, and is directed distally, its beak-like apex giving rise to the ligament of Struthers that inserts on the medial epicondyle. The constellation of symptoms associated with entrapment of the brachial artery and median nerve beneath the ligament of Struthers is known as “supracondylar process syndrome.” Symptoms include paresthesia, weakness, and muscle wasting related to the median nerve. Vascular symptoms related to the brachial artery include ischemic pain and claudication in the forearm. The symptoms are typically exacerbated by extension and pronation of the forearm, as well as repetitive activities.4 However, most supracondylar processes are asymptomatic and are incidentally identified on humeral radiographs. Therefore correlation of the radiologic and clinical findings is important. The differential diagnosis includes an osteochondroma and myositis ossificans of the humerus, which have characteristic radiographic appearances that differ from a supracondylar spur. On clinical assessment, it is important to rule out other sources of nerve compression both proximal and distal to the elbow. The spur is usually palpable, and a positive Tinel sign may be elicited just distal to the prominence. Symptoms may be reproduced by provocative maneuvers. Plain radiographs will show the supracondylar process (Fig 1A), and a computed tomography arteriogram is valuable to understand the relation of the brachial
Arthroscopy Techniques, Vol 5, No 1 (February), 2016: pp e67-e70
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Fig 1. (A) Anteroposterior radiograph of an elbow showing a supracondylar spur pointing downward, present at the medial aspect of the distal humerus. (B) Computed tomography arteriogram of the upper limb showing the brachial artery passing and kinking under the supracondylar spur. Ó 2016 Gregory Bain. All Rights Reserved.
artery and the supracondylar process (Fig 1B). In the presented case the nerve conduction studies were equivocal and an ultrasound scan confirmed the median nerve to be beneath the process. Conservative treatment with splinting, activity modification, and physiotherapy was unsuccessful; hence surgical decompression was performed. In the presence of persistent symptoms failing nonoperative modalities or in the presence of muscle wasting or weakness, surgical decompression should be considered. This usually involves open surgical excision of the supracondylar process with the overlying periosteum5 and resection of the associated ligament of Struthers. We describe a minimally invasive endoscopic
Fig 2. Intraoperative photograph showing the median nerve under the supracondylar spur. The inset shows the relation of the Struthers ligament (lig) with the median nerve (n), brachial artery (a), and ulnar nerve. Ó 2016 Gregory Bain. All Rights Reserved.
technique for excision of the supracondylar process and decompression of the median nerve and brachial artery, adapted from our experience performing endoscopic surgery around the elbow.6-9
Surgical Technique Setup Under general anesthesia, a pneumatic tourniquet is applied and the patient is positioned supine with the operative arm in 90 of shoulder abduction on a standard hand table (Video 1). The upper extremity is draped to allow full mobility of the arm. The surgeon flexes the elbow and externally rotates the shoulder to
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optimize the orientation of the operative field. A sterile roll comprising a sheet may be placed under the elbow to elevate the arm. Exposure A 3-cm skin incision is made just distal to the palpable supracondylar process over the medial supracondylar ridge. An endoscopic working space is created between the forearm fascia and the subcutaneous tissue for approximately 5 cm distally and proximally. This is created initially with blunt dissection, until the deep fascia is identified, and is then expanded with the assistance of retractors and tunneling forceps. The deep fascia is incised, and a hooded 4.0-mm 30 arthroscope (Karl Storz, Tuttlingen, Germany) is inserted into the working space. The median nerve and the brachial artery are identified and are traced proximally, which directs the surgeon to the supracondylar spur and the ligament of Struthers. The ligament of Struthers is a taut thick fibrous band that spans from the process, over the brachial artery and median nerve, to the medial epicondyle (Fig 2). The humeral head of the pronator teres is attached to the medial aspect of the ligament. Endoscopic Decompression The exact orientations of the ligament, process, and neurovascular structures are identified. The neurovascular structures are decompressed by incising the Struthers ligament with scissors (Fig 3A). The ligament and process are then excised with a Kerrison rongeur to minimize the chance of the ligament re-forming (Fig 3B). Under endoscopic vision, the neurovascular structures are released proximally and distally, including the arch of the flexor digitorum superficialis. The tourniquet is released, and hemostasis is achieved under endoscopic vision.
Fig 3. Intraoperative photographs showing excision of Struthers ligament with scissors (A) and excision of supracondylar spur with Kerrison rongeur (B). Ó 2016 Gregory Bain. All Rights Reserved.
Table 1. Tips and Tricks Because of the temperature difference between the soft-tissue space and the lens of the arthroscope, condensation on the arthroscope lens is not uncommon. Wiping the lens with an alcohol swab or immersing the arthroscope tip in warm saline solution before starting the procedure can minimize condensation. During the procedure, the view can become compromised with blood, debris, or condensation on the arthroscope lens. The lens can be dabbed on the surrounding fat, which cleans the arthroscope and minimizes the recurrence of condensation. If this is unsuccessful, the arthroscope can be removed and lens wiped with an alcohol wipe or glycerin. In case of blood obscuring the field of view, washing with 5 mL of saline solution through the side valve of the arthroscope and then aspirating with suction or a chondrotome are helpful. The hooded arthroscope works like a tent post, elevating the subcutaneous tissues, to maintain the endoscopic space.
Postoperative Care After surgery, the patient is given a sling and is advised that he or she can remove the sling and mobilize the arm as comfort allows. The patient can be discharged the same day but should be assessed before discharge to ensure that there is no excessive bleeding or hematoma. The patient then undergoes a review in the clinic 1 week later to ensure that he or she is making a satisfactory recovery and that the neurologic symptoms are recovering. Tips and Tricks Table 1 presents tips and tricks on performing our technique.
Discussion Endoscopic assessment provides an amazing view of the soft tissues around the elbow. The advantages include the following: Such assessment provides a magnified view of the anatomy so that the specific
e70
G. BAIN ET AL.
details of each structure can be appreciated and the release can be performed with precision. It provides a new insight into the anatomy. Hoffmann and Lubahn9 identified that the deep surface of the flexor carpi ulnaris muscle had a thickened fascial layer. In our case the detail of the vascular anatomy provided new insight into the venous system of the region. This technique provides another extension of the new concepts of endoscopic surgery around the elbow. Hoffmann and Lubahn10 initially described using a hooded arthroscope or speculum to visualize the ulnar nerve and then divide the cubital retinaculum with scissors to release the ulnar nerve. Bipolar cautery was used to obtain hemostasis. In our technique the Struthers ligament is divided with scissors, and the Kerrison rongeur is used to resect the supracondylar spur. However, there have been other endoscopic advances in recent times that included the following: Anterior interosseous nerve11dusing scissors to release the pronator teres entrapment of the anterior interosseous nerve. Olecranon bursa9dcreating a second working portal to introduce instruments to resect the olecranon bursa, with instruments such as a motorized shaver and pituitary rongeur. Ulnar nerve transposition7dintroducing a second port to retract the ulnar nerve to allow an artery clip to safely be placed onto the free edge of the medial intermuscular septum so that it can be resected and then introducing a nylon tape through a third portal to control the position of the ulnar nerve so that it can be transposed. Endoscopic-assisted biceps tendon repair8dusing a Wissinger rod to create a second portal and performing an endoscopic-assisted distal biceps tendon repair, which includes debriding the tendon footprint with a motorized shaver, drilling the radius, and advancing sutures through the radius. The endoscopic procedures are minimally invasive techniques that are performed with magnification, which allows dissection to be performed with precision.
In our experience, these tend to use less soft-tissue dissection, to cause less postoperative bruising, and to allow a faster rehabilitation. Many of the concepts used in open surgery are now being used for endoscopic surgery, and vice versa. The barriers among endoscopic, arthroscopic, and open procedures are being broken down. We report another advanced endoscopic technique, which is part of the evolution of musculoskeletal surgery.
References 1. Tiedemann F. Veber einen am oberarmbein bei mehreren geschwanzten affen vorkommenden kanal und cine damit in verbindung stehende be- sondere anordnung der arterien und nerveu des arms. Deutsches Archiv Fur die Physiologie 1818;4:544-549 [in German]. 2. Struthers J. On a peculiarity of the humerus and humeral artery. Month J Med Sci 1849;28:264-267. 3. Krishnamurthy J, Lakshminarayan JLG. Supracondylar process of the humerusdA case report. Int J Anat Var 2013;6:98-100. 4. Ivins GK. Supracondylar process syndrome: A case report. J Hand Surg Am 1996;21:279-281. 5. Spinner RJ, Lins RE, Jacobson SR, Nunley JA. Fractures of the supracondylar process of the humerus. J Hand Surg Am 1994;19:1038-1041. 6. Endoscopy around the elbow. In: Pederzini LA, Bain G, Safran MR, eds. Elbow arthroscopy. Verlag Berlin Heidelberg: Springer, 2013;73-81. 7. Morse LP, McGuire DT, Bain GI. Endoscopic ulnar nerve release and transposition. Tech Hand Up Extrem Surg 2014;18:10-14. 8. Phadnis J, Bain GI. Endoscopic-assisted distal biceps footprint repair. Tech Hand Up Extrem Surg 2015;19:55-59. 9. Tu CG, McGuire DT, Morse LP, Bain GI. Olecranon extrabursal endoscopic bursectomy. Tech Hand Up Extrem Surg 2013;17:173-175. 10. Hoffmann R, Lubahn J. Endoscopic cubital tunnel release using the Hoffmann technique. J Hand Surg Am 2013;38: 1234-1239. 11. Damert HG, Hoffmann R, Kraus A, Stowell RL, Lubahn J. Minimally invasive endoscopic decompression for anterior interosseous nerve syndrome: Technical notes. J Hand Surg Am 2013;38:2016-2024.
Abstract: The humeral supracondylar process and Struthers ligament comprise a relatively rare but well-known anatomic variant. They are usually asymptomatic but may produce clinical symptoms related to compression of the median nerve or brachial artery below the ligament. Previously, surgery has been performed with an open ligament release and supracondylar process excision. This article reports on the use of endoscopic findings and the method of ligament release and process excision. Endoscopy is a minimally invasive technique that provides excellent visualization and enables the surgeon to perform dissection with magnification and precision. It allows the surgeon to introduce open surgical techniques into the depths of the wound in a controlled manner. Because of the dead space created, there is a risk of hematoma formation. Many of the concepts used in open surgery are now being used for endoscopic surgery, and vice versa. The barriers and differences among endoscopic, arthroscopic, and open procedures are being broken down. We report another endoscopic technique, which is part of the ongoing evolution of musculoskeletal surgery.
T
he supracondylar spur or process was noted by Tiedmann1 in 1818 and described further by Struthers in 18482 as a bony projection on the anteromedial humerus approximately 5 cm proximal to the medial epicondyle. It occurs in 0.4% to 2.7% of the worldwide population.3 The supracondylar process is a normal anatomic variant that represents the embryologic vestigial remnant of the latissimo-condyloideus, a muscle that is still present in climbing animals, many reptiles, and cats. In humans this muscle is usually represented as a fibrous band between the tendons of the latissimus dorsi and coracobrachialis.3 The bone formation starts from a broad base, about 7 cm
From the Department of Orthopaedic Surgery, Flinders University (G.B., P.G., J.P., P.K.S.), Adelaide, Australia; Department of Orthopaedic Surgery, Flinders Medical Centre (G.B., P.G., J.P., P.K.S.), Adelaide, Australia; International Musculoskeletal Research Institute (G.B., P.G., J.P., P.K.S.), Adelaide, Australia; and Alchemist Hospital (P.G.), Gurgaon, India. The authors report that they have no conflicts of interest in the authorship and publication of this article. Received June 20, 2015; accepted August 28, 2015. Address correspondence to Prince Gupta, House No. 172, Sector 12 a, Gurgaon 122001, Haryana, India. E-mail: [email protected] Ó 2016 Arthroscopy Association of North America. Published by Elsevier. All rights reserved 2212-6287/15564/$36.00 http://dx.doi.org/10.1016/j.eats.2015.08.019
proximal to the medial epicondyle, and is directed distally, its beak-like apex giving rise to the ligament of Struthers that inserts on the medial epicondyle. The constellation of symptoms associated with entrapment of the brachial artery and median nerve beneath the ligament of Struthers is known as “supracondylar process syndrome.” Symptoms include paresthesia, weakness, and muscle wasting related to the median nerve. Vascular symptoms related to the brachial artery include ischemic pain and claudication in the forearm. The symptoms are typically exacerbated by extension and pronation of the forearm, as well as repetitive activities.4 However, most supracondylar processes are asymptomatic and are incidentally identified on humeral radiographs. Therefore correlation of the radiologic and clinical findings is important. The differential diagnosis includes an osteochondroma and myositis ossificans of the humerus, which have characteristic radiographic appearances that differ from a supracondylar spur. On clinical assessment, it is important to rule out other sources of nerve compression both proximal and distal to the elbow. The spur is usually palpable, and a positive Tinel sign may be elicited just distal to the prominence. Symptoms may be reproduced by provocative maneuvers. Plain radiographs will show the supracondylar process (Fig 1A), and a computed tomography arteriogram is valuable to understand the relation of the brachial
Arthroscopy Techniques, Vol 5, No 1 (February), 2016: pp e67-e70
e67
e68
G. BAIN ET AL.
Fig 1. (A) Anteroposterior radiograph of an elbow showing a supracondylar spur pointing downward, present at the medial aspect of the distal humerus. (B) Computed tomography arteriogram of the upper limb showing the brachial artery passing and kinking under the supracondylar spur. Ó 2016 Gregory Bain. All Rights Reserved.
artery and the supracondylar process (Fig 1B). In the presented case the nerve conduction studies were equivocal and an ultrasound scan confirmed the median nerve to be beneath the process. Conservative treatment with splinting, activity modification, and physiotherapy was unsuccessful; hence surgical decompression was performed. In the presence of persistent symptoms failing nonoperative modalities or in the presence of muscle wasting or weakness, surgical decompression should be considered. This usually involves open surgical excision of the supracondylar process with the overlying periosteum5 and resection of the associated ligament of Struthers. We describe a minimally invasive endoscopic
Fig 2. Intraoperative photograph showing the median nerve under the supracondylar spur. The inset shows the relation of the Struthers ligament (lig) with the median nerve (n), brachial artery (a), and ulnar nerve. Ó 2016 Gregory Bain. All Rights Reserved.
technique for excision of the supracondylar process and decompression of the median nerve and brachial artery, adapted from our experience performing endoscopic surgery around the elbow.6-9
Surgical Technique Setup Under general anesthesia, a pneumatic tourniquet is applied and the patient is positioned supine with the operative arm in 90 of shoulder abduction on a standard hand table (Video 1). The upper extremity is draped to allow full mobility of the arm. The surgeon flexes the elbow and externally rotates the shoulder to
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optimize the orientation of the operative field. A sterile roll comprising a sheet may be placed under the elbow to elevate the arm. Exposure A 3-cm skin incision is made just distal to the palpable supracondylar process over the medial supracondylar ridge. An endoscopic working space is created between the forearm fascia and the subcutaneous tissue for approximately 5 cm distally and proximally. This is created initially with blunt dissection, until the deep fascia is identified, and is then expanded with the assistance of retractors and tunneling forceps. The deep fascia is incised, and a hooded 4.0-mm 30 arthroscope (Karl Storz, Tuttlingen, Germany) is inserted into the working space. The median nerve and the brachial artery are identified and are traced proximally, which directs the surgeon to the supracondylar spur and the ligament of Struthers. The ligament of Struthers is a taut thick fibrous band that spans from the process, over the brachial artery and median nerve, to the medial epicondyle (Fig 2). The humeral head of the pronator teres is attached to the medial aspect of the ligament. Endoscopic Decompression The exact orientations of the ligament, process, and neurovascular structures are identified. The neurovascular structures are decompressed by incising the Struthers ligament with scissors (Fig 3A). The ligament and process are then excised with a Kerrison rongeur to minimize the chance of the ligament re-forming (Fig 3B). Under endoscopic vision, the neurovascular structures are released proximally and distally, including the arch of the flexor digitorum superficialis. The tourniquet is released, and hemostasis is achieved under endoscopic vision.
Fig 3. Intraoperative photographs showing excision of Struthers ligament with scissors (A) and excision of supracondylar spur with Kerrison rongeur (B). Ó 2016 Gregory Bain. All Rights Reserved.
Table 1. Tips and Tricks Because of the temperature difference between the soft-tissue space and the lens of the arthroscope, condensation on the arthroscope lens is not uncommon. Wiping the lens with an alcohol swab or immersing the arthroscope tip in warm saline solution before starting the procedure can minimize condensation. During the procedure, the view can become compromised with blood, debris, or condensation on the arthroscope lens. The lens can be dabbed on the surrounding fat, which cleans the arthroscope and minimizes the recurrence of condensation. If this is unsuccessful, the arthroscope can be removed and lens wiped with an alcohol wipe or glycerin. In case of blood obscuring the field of view, washing with 5 mL of saline solution through the side valve of the arthroscope and then aspirating with suction or a chondrotome are helpful. The hooded arthroscope works like a tent post, elevating the subcutaneous tissues, to maintain the endoscopic space.
Postoperative Care After surgery, the patient is given a sling and is advised that he or she can remove the sling and mobilize the arm as comfort allows. The patient can be discharged the same day but should be assessed before discharge to ensure that there is no excessive bleeding or hematoma. The patient then undergoes a review in the clinic 1 week later to ensure that he or she is making a satisfactory recovery and that the neurologic symptoms are recovering. Tips and Tricks Table 1 presents tips and tricks on performing our technique.
Discussion Endoscopic assessment provides an amazing view of the soft tissues around the elbow. The advantages include the following: Such assessment provides a magnified view of the anatomy so that the specific
e70
G. BAIN ET AL.
details of each structure can be appreciated and the release can be performed with precision. It provides a new insight into the anatomy. Hoffmann and Lubahn9 identified that the deep surface of the flexor carpi ulnaris muscle had a thickened fascial layer. In our case the detail of the vascular anatomy provided new insight into the venous system of the region. This technique provides another extension of the new concepts of endoscopic surgery around the elbow. Hoffmann and Lubahn10 initially described using a hooded arthroscope or speculum to visualize the ulnar nerve and then divide the cubital retinaculum with scissors to release the ulnar nerve. Bipolar cautery was used to obtain hemostasis. In our technique the Struthers ligament is divided with scissors, and the Kerrison rongeur is used to resect the supracondylar spur. However, there have been other endoscopic advances in recent times that included the following: Anterior interosseous nerve11dusing scissors to release the pronator teres entrapment of the anterior interosseous nerve. Olecranon bursa9dcreating a second working portal to introduce instruments to resect the olecranon bursa, with instruments such as a motorized shaver and pituitary rongeur. Ulnar nerve transposition7dintroducing a second port to retract the ulnar nerve to allow an artery clip to safely be placed onto the free edge of the medial intermuscular septum so that it can be resected and then introducing a nylon tape through a third portal to control the position of the ulnar nerve so that it can be transposed. Endoscopic-assisted biceps tendon repair8dusing a Wissinger rod to create a second portal and performing an endoscopic-assisted distal biceps tendon repair, which includes debriding the tendon footprint with a motorized shaver, drilling the radius, and advancing sutures through the radius. The endoscopic procedures are minimally invasive techniques that are performed with magnification, which allows dissection to be performed with precision.
In our experience, these tend to use less soft-tissue dissection, to cause less postoperative bruising, and to allow a faster rehabilitation. Many of the concepts used in open surgery are now being used for endoscopic surgery, and vice versa. The barriers among endoscopic, arthroscopic, and open procedures are being broken down. We report another advanced endoscopic technique, which is part of the evolution of musculoskeletal surgery.
References 1. Tiedemann F. Veber einen am oberarmbein bei mehreren geschwanzten affen vorkommenden kanal und cine damit in verbindung stehende be- sondere anordnung der arterien und nerveu des arms. Deutsches Archiv Fur die Physiologie 1818;4:544-549 [in German]. 2. Struthers J. On a peculiarity of the humerus and humeral artery. Month J Med Sci 1849;28:264-267. 3. Krishnamurthy J, Lakshminarayan JLG. Supracondylar process of the humerusdA case report. Int J Anat Var 2013;6:98-100. 4. Ivins GK. Supracondylar process syndrome: A case report. J Hand Surg Am 1996;21:279-281. 5. Spinner RJ, Lins RE, Jacobson SR, Nunley JA. Fractures of the supracondylar process of the humerus. J Hand Surg Am 1994;19:1038-1041. 6. Endoscopy around the elbow. In: Pederzini LA, Bain G, Safran MR, eds. Elbow arthroscopy. Verlag Berlin Heidelberg: Springer, 2013;73-81. 7. Morse LP, McGuire DT, Bain GI. Endoscopic ulnar nerve release and transposition. Tech Hand Up Extrem Surg 2014;18:10-14. 8. Phadnis J, Bain GI. Endoscopic-assisted distal biceps footprint repair. Tech Hand Up Extrem Surg 2015;19:55-59. 9. Tu CG, McGuire DT, Morse LP, Bain GI. Olecranon extrabursal endoscopic bursectomy. Tech Hand Up Extrem Surg 2013;17:173-175. 10. Hoffmann R, Lubahn J. Endoscopic cubital tunnel release using the Hoffmann technique. J Hand Surg Am 2013;38: 1234-1239. 11. Damert HG, Hoffmann R, Kraus A, Stowell RL, Lubahn J. Minimally invasive endoscopic decompression for anterior interosseous nerve syndrome: Technical notes. J Hand Surg Am 2013;38:2016-2024.