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Distal Clavicle Fracture as a Complication of Arthroscopic Distal Clavicle Resection
Case Report
Distal Clavicle Fracture as a Complication of Arthroscopic Distal Clavicle Resection Neil Ghodadra, M.D., Gregory H. Lee, M.D., Peter Kung, M.D., Benjamin T. Busfield, M.S., M.D., and F. Daniel Kharazzi, M.D.
Abstract: Arthroscopic resection of the distal clavicle has been advocated as a surgical treatment option for acromioclavicular (AC) joint pathology. To our knowledge, iatrogenic fracture of the distal clavicle during distal clavicle resection has never been reported. This report describes distal clavicle fracture as a complication of misidentification of the AC joint and subsequent aggressive burring of the distal clavicle during shoulder arthroscopy. This case is further complicated by the development of symptomatic delayed union and adhesive capsulitis. Ultimately, a revision distal clavicle resection was performed, underscoring the fact that special care must be taken to properly identify the AC joint and rule out pre-existing distal clavicle stress fracture or osteolysis before performing the arthroscopic Mumford procedure. Key Words: Clavicle fracture—Adhesive capsulitis—Shoulder—Mumford.
A
lthough distal clavicle fractures are not uncommon after trauma, fracture after arthroscopic surgery of the acromioclavicular (AC) joint has not previously been reported. Distal clavicle fractures comprise 15% of all traumatic clavicular fractures and can result in long-term complications including chronic pain, nonunion, and decreased shoulder mobility.1-4 Arthroscopic resection of the distal clavicle has been advocated for treatment of AC joint pathology.5-10 To our knowledge, iatrogenic fracture of the distal clavicle during distal clavicle resection has never been reported. This report describes a distal clavicle comminuted fracture from a technical error in identifying the AC joint and subsequent burring of the distal clavicle during arthroscopic
From the Department of Orthopedic Surgery, Rush Medical Center (N.G.), Chicago, Illinois, and Kerlan-Jobe Orthopaedic Clinic (G.H.L., P.K., B.T.B., F.D.K.), Los Angeles, California, U.S.A. Address correspondence and reprint requests to Neil Ghodadra, M.D., Department of Orthopedic Surgery, Rush Medical Center, 1725 W Harrison Pkwy, Suite 1063, Chicago, IL, U.S.A. E-mail: [email protected] © 2009 by the Arthroscopy Association of North America 0749-8063/09/2508-0931$36.00/0 doi:10.1016/j.arthro.2009.02.008
shoulder surgery. This case is complicated by the development of symptomatic delayed union, adhesive capsulitis, and ultimately, a revision distal clavicle resection. CASE REPORT A 47-year-old right hand– dominant male drill-press operator came to our clinic for a second opinion 4 months after sustaining a work-related injury to his right shoulder. He was diagnosed with subacromial impingement and treated with physical therapy by another physician. Because of continued shoulder pain and stiffness recalcitrant to 3 months of conservative treatment, the patient underwent a shoulder arthroscopy with subacromial decompression and distal clavicle resection. On the night of his surgery, he reported severe pain after hearing a loud pop in his shoulder without any trauma. After another physician performed an evaluation and obtained radiographs, the patient was referred to our office for a second opinion. On our physical examination, there was no obvious deformity or muscle atrophy of the patient’s right shoulder. Palpation showed an intact AC joint with
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 25, No 8 (August), 2009: pp 929-933
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FIGURE 2. CT scan of right shoulder, axial view. The asterisk shows a comminuted fracture at the distal aspect of the clavicle.
FIGURE 1. Radiograph of right shoulder, anteroposterior view. The arrow shows fracture at the distal end of the clavicle.
severe pain 2 cm medial to the distal end of his right clavicle. He showed severe guarding with any motion of his shoulder and had extreme pain at 90° of forward flexion. Neer and Hawkins testing caused him significant discomfort and pain. Passive cross-body adduction also caused severe pain. The findings on examination of his contralateral shoulder were normal. Radiographs showed evidence of a fracture approximately 3 cm medial to the distal end of the clavicle (Fig 1). There was also evidence of a type II acromion. Given the unclear mechanism for the distal clavicle fracture, magnetic resonance imaging (MRI) and computed tomography (CT) were performed to evaluate the extent of injury. The MRI scan showed a comminuted fracture of the distal clavicle with surrounding bone and soft-tissue edema and an edematous change at the insertion of the rotator cuff consistent with tendinosis. The CT scan confirmed a comminuted fracture of the distal clavicle (Fig 2). Initial management consisted of work restriction and sling immobilization. The patient was encouraged to perform gentle range-of-motion exercises. At 6 weeks’ follow-up after our initial assessment and 10 weeks after shoulder arthroscopy, he continued to have severe discomfort and tenderness at the fracture site. Repeat radiographs showed evidence of slight callus formation (Fig 3). Four months after shoulder
arthroscopy, the patient continued to have significant distal clavicle tenderness with no improvement in symptoms. He also had significant posterior girdle shoulder tenderness and supraspinatus atrophy of his right shoulder. Repeat radiographs at that time showed significant callus formation at the fracture site (Fig 4). The patient began an aggressive physical therapy program with continued work restrictions.
FIGURE 3. Anteroposterior radiograph of right shoulder. The arrow shows callus formation at the distal aspect of the clavicle.
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FIGURE 6. Right shoulder, coronal CT view. The arrow shows callus formation on the superior aspect of the AC joint.
FIGURE 4. Anteroposterior radiograph of right shoulder. The arrow shows significant callus formation at the distal aspect of the clavicle.
At 6 months’ follow-up after the patient’s initial shoulder surgery, he continued to show no improvement in shoulder pain, and a significant lack of internal and external rotation developed. His range of motion was limited by pain to 85° of abduction and forward flexion, external rotation to 15° at his side, and internal rotation to 25° at his side. He also had moderate atrophy of his periscapular musculature and rotator cuff. Repeat radiographs showed significant
FIGURE 5. Anteroposterior radiograph of right shoulder. The arrow shows significant callus formation and a high-riding clavicle.
callus formation at the fracture site of the distal clavicle and evidence of a high-riding distal end of the clavicle approximately 8 mm cephalad to the acromion (Fig 5). As a result of his continued symptoms and development of adhesive capsulitis, the patient was given a subacromial injection to help decrease inflammation and allow more time for bony union of the fracture site. He had no relief of symptoms and was seen at 8 months after the initial surgery, when repeat radiographs and a CT scan were obtained, which showed evidence of consolidation at the fracture site (Fig 6). Given the patient’s unremitting symptoms and evidence of adhesive capsulitis despite a radiographically healed distal clavicle fracture, we recommended a shoulder arthroscopy with revision subacromial decompression, revision distal clavicle resection, and capsular release with lysis of adhesions. On diagnostic arthroscopy, he was found to have grade II chondral changes in the glenoid, tenosynovitis of the biceps, and a frayed superior labrum. During subacromial decompression, the coracoacromial ligament was noted to be frayed and was resected from the acromion. This uncovered a large anterolateral subacromial spur and associated fraying on the bursal side of the rotator cuff. This spur was then resected (Fig 7). Extensive synovitis and degeneration were noted at the AC joint. Visualization of the AC joint showed previous iatrogenic bone loss from burring. The terminal 1 cm of the distal clavicle was resected (Fig 8). Four months after surgery, the patient had shoulder motion of 160° in forward flexion, 162° in abduction, 78° of external rotation with the arm ab-
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FIGURE 7. Arthroscopic view of acromion from posterior portal in right shoulder. The shaver introduced from the lateral working portal and the subacromial spur on the anterolateral acromion should be noted.
ducted, and internal rotation to the L1 level. He also had a dramatic reduction in shoulder pain at the distal clavicle. Six months postoperatively, he has returned to all desired activities including his occupation as a drill-press operator. DISCUSSION The distal clavicle can be resected by either open or arthroscopic technique.11,12 Recently, arthroscopic resection of the distal clavicle has gained in popularity with its potential for decreased morbidity, reduced intraoperative blood loss, improved cosmesis, and reduced postoperative pain.5,13 To our knowledge, this is the first reported case in the literature of a distal clavicle fracture as a complication of shoulder arthroscopy. In this case union was delayed, the patient continued to have pain, and adhesive capsulitis subsequently developed. This initial report of distal clavicle fracture as a possible complication of the arthroscopic Mumford procedure underscores the importance of proper identification of the AC joint before performing an arthroscopic distal clavicle resection. In this report the initial surgeon likely failed to accurately identify the AC joint and subsequently burred the distal 2 cm of the clavicle, causing a distal clavicle fracture. This complication highlights the importance of proper identification of the AC joint before performing a distal clavicle resection. The surgeon can attain proper visualization of the AC joint from the posterior portal after careful resection of the coracoacromial ligament
in a lateral-to-medial direction with a radiofrequency device. After thorough soft-tissue debridement, the surgeon can palpate the distal clavicle and provide an inferiorly directed force to visualize translation of the clavicle at the AC joint. This technique can assist the surgeon in properly identifying the AC joint and, specifically, the distal clavicle before resection. In addition to careful identification of the AC joint, the surgeon should preoperatively determine the potential for distal clavicle pathology before resection. Preoperative MRI films of our patient showed increased AC joint arthrosis and distal clavicle edema. He may have had pre-existing nontraumatic osteolysis of the distal clavicle due to repetitive lifting or microtrauma, thus predisposing him to iatrogenic distal clavicle trauma during arthroscopic burring. Multiple studies have described nontraumatic osteolysis of the distal clavicle associated with repetitive heavy lifting of objects.14-17 Another proposed mechanism of osteolysis suggests that repeated stresses on subchondral bone result in microfracture and subsequent bone resorption.14,18 Increased signal in the AC joint and distal clavicle in this patient suggests a significant traumatic load generated through the distal clavicle and into the AC joint. This finding highlights the importance of proper identification of the AC joint during arthroscopic distal clavicle resection. Post-traumatic osteoarthritis and symptomatic nonunion are potential sequelae from nonoperative treatment of distal clavicle fractures. Distal clavicle fractures account for 50% of all cases of nonunion in clavicle fractures.1 This high rate of nonunion is considered to result from the high number of muscular
FIGURE 8. Arthroscopic view of AC joint from posterior portal in right shoulder. The shaver introduced from the lateral working portal and the distal end of the clavicle (asterisk) should be noted.
DISTAL CLAVICLE FRACTURE forces that act on the shoulder girdle, preventing adequate bony contact necessary to progress to union. With increased delay to union and continued pain at the distal clavicle fracture site, debilitating adhesive capsulitis developed in our patient.19 Although the nonunion rate of distal clavicle fractures has been reported to be as high as 30%,2 adhesive capsulitis has not been described as a complication of distal clavicle fracture. In this case adhesive capsulitis occurred in the patient because he was unable to pursue aggressive physical therapy because of debilitating clavicular pain. In cases of distal clavicle fractures leading to painful nonunion or AC joint arthritis, distal clavicle resection can provide good results.20 At 6 months’ follow-up, our patient has noted significant improvement in pain and function of his affected shoulder. Other potential causes of this fracture, such as an anatomic variant or unfused epiphysis, were also investigated. Radiography of both shoulders was performed, and no evidence was found to confirm the presence of an unfused distal clavicle epiphysis in the contralateral shoulder. Another potential source of preexisting bone weakness is tumor or metabolic disease. Distal clavicle fractures should be considered as a potential complication of misidentification of the AC joint and subsequent aggressive burring of the distal clavicle during shoulder arthroscopy. Special care must be taken to properly identify the AC joint and rule out pre-existing distal clavicle stress fracture or osteolysis before performing the arthroscopic Mumford procedure. Similar to traumatic fractures of the distal clavicle, iatrogenic fractures of the distal clavicle are at risk of delayed union and persistent symptoms and complications including adhesive capsulitis. Operative resection of the distal clavicle should prove to be successful if conservative management of this injury fails. REFERENCES 1. Checchia SL, Doneux PS, Miyazaki AN, Fregoneze M, Silva LA. Treatment of distal clavicle fractures using an arthroscopic technique. J Shoulder Elbow Surg 2008;17:395-398.
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2. Neer CS II. Fracture of the distal clavicle with detachment of the coracoclavicular ligaments in adults. J Trauma 1963;3:99110. 3. Heppenstall RB. Fractures and dislocations of the distal clavicle. Orthop Clin North Am 1975;6:477-486. 4. Allman FL Jr. Fractures and ligamentous injuries of the clavicle and its articulation. J Bone Joint Surg Am 1967;49:774784. 5. Flatow EL, Duralde XA, Nicholson GP, Pollock RG, Bigliani LU. Arthroscopic resection of the distal clavicle with a superior approach. J Shoulder Elbow Surg 1995;4:41-50. 6. Gartsman GM. Arthroscopic resection of the acromioclavicular joint. Am J Sports Med 1993;21:71-77. 7. Kay SP, Ellman H, Harris E. Arthroscopic distal clavicle excision. Technique and early results. Clin Orthop Relat Res 1994:181-184. 8. Bigliani LU, Nicholson GP, Flatow EL. Arthroscopic resection of the distal clavicle. Orthop Clin North Am 1993; 24:133-141. 9. Edwards SL, Wilson NA, Flores SE, Koh JL, Zhang LQ. Arthroscopic distal clavicle resection: A biomechanical analysis of resection length and joint compliance in a cadaveric model. Arthroscopy 2007;23:1278-1284. 10. Rabalais RD, McCarty E. Surgical treatment of symptomatic acromioclavicular joint problems: A systematic review. Clin Orthop Relat Res 2007;455:30-37. 11. Chronopoulos E, Gill HS, Freehill MT, Petersen SA, McFarland EG. Complications after open distal clavicle excision. Clin Orthop Relat Res 2008;466:646-651. 12. Freedman BA, Javernick MA, O’Brien FP, Ross AE, Doukas WC. Arthroscopic versus open distal clavicle excision: Comparative results at six months and one year from a randomized, prospective clinical trial. J Shoulder Elbow Surg 2007;16:413418. 13. Snyder SJ, Banas MP, Karzel RP. The arthroscopic Mumford procedure: An analysis of results. Arthroscopy 1995;11:157164. 14. Cahill BR. Atraumatic osteolysis of the distal clavicle. A review. Sports Med 1992;13:214-222. 15. Cahill BR. Osteolysis of the distal part of the clavicle in male athletes. J Bone Joint Surg Am 1982;64:1053-1058. 16. Scavenius M, Iversen BF. Nontraumatic clavicular osteolysis in weight lifters. Am J Sports Med 1992;20:463-467. 17. Schwarzkopf R, Ishak C, Elman M, Gelber J, Strauss DN, Jazrawi LM. Distal clavicular osteolysis: A review of the literature. Bull NYU Hosp Jt Dis 2008;66:94-101. 18. Kaplan PA, Resnick D. Stress-induced osteolysis of the clavicle. Radiology 1986;158:139-140. 19. Tauro JC, Paulson M. Shoulder stiffness. Arthroscopy 2008; 24:949-955. 20. Shellhaas JS, Glaser DL, Drezner JA. Distal clavicular stress fracture in a female weight lifter: A case report. Am J Sports Med 2004;32:1755-1758.
Distal Clavicle Fracture as a Complication of Arthroscopic Distal Clavicle Resection Neil Ghodadra, M.D., Gregory H. Lee, M.D., Peter Kung, M.D., Benjamin T. Busfield, M.S., M.D., and F. Daniel Kharazzi, M.D.
Abstract: Arthroscopic resection of the distal clavicle has been advocated as a surgical treatment option for acromioclavicular (AC) joint pathology. To our knowledge, iatrogenic fracture of the distal clavicle during distal clavicle resection has never been reported. This report describes distal clavicle fracture as a complication of misidentification of the AC joint and subsequent aggressive burring of the distal clavicle during shoulder arthroscopy. This case is further complicated by the development of symptomatic delayed union and adhesive capsulitis. Ultimately, a revision distal clavicle resection was performed, underscoring the fact that special care must be taken to properly identify the AC joint and rule out pre-existing distal clavicle stress fracture or osteolysis before performing the arthroscopic Mumford procedure. Key Words: Clavicle fracture—Adhesive capsulitis—Shoulder—Mumford.
A
lthough distal clavicle fractures are not uncommon after trauma, fracture after arthroscopic surgery of the acromioclavicular (AC) joint has not previously been reported. Distal clavicle fractures comprise 15% of all traumatic clavicular fractures and can result in long-term complications including chronic pain, nonunion, and decreased shoulder mobility.1-4 Arthroscopic resection of the distal clavicle has been advocated for treatment of AC joint pathology.5-10 To our knowledge, iatrogenic fracture of the distal clavicle during distal clavicle resection has never been reported. This report describes a distal clavicle comminuted fracture from a technical error in identifying the AC joint and subsequent burring of the distal clavicle during arthroscopic
From the Department of Orthopedic Surgery, Rush Medical Center (N.G.), Chicago, Illinois, and Kerlan-Jobe Orthopaedic Clinic (G.H.L., P.K., B.T.B., F.D.K.), Los Angeles, California, U.S.A. Address correspondence and reprint requests to Neil Ghodadra, M.D., Department of Orthopedic Surgery, Rush Medical Center, 1725 W Harrison Pkwy, Suite 1063, Chicago, IL, U.S.A. E-mail: [email protected] © 2009 by the Arthroscopy Association of North America 0749-8063/09/2508-0931$36.00/0 doi:10.1016/j.arthro.2009.02.008
shoulder surgery. This case is complicated by the development of symptomatic delayed union, adhesive capsulitis, and ultimately, a revision distal clavicle resection. CASE REPORT A 47-year-old right hand– dominant male drill-press operator came to our clinic for a second opinion 4 months after sustaining a work-related injury to his right shoulder. He was diagnosed with subacromial impingement and treated with physical therapy by another physician. Because of continued shoulder pain and stiffness recalcitrant to 3 months of conservative treatment, the patient underwent a shoulder arthroscopy with subacromial decompression and distal clavicle resection. On the night of his surgery, he reported severe pain after hearing a loud pop in his shoulder without any trauma. After another physician performed an evaluation and obtained radiographs, the patient was referred to our office for a second opinion. On our physical examination, there was no obvious deformity or muscle atrophy of the patient’s right shoulder. Palpation showed an intact AC joint with
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 25, No 8 (August), 2009: pp 929-933
929
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N. GHODADRA ET AL.
FIGURE 2. CT scan of right shoulder, axial view. The asterisk shows a comminuted fracture at the distal aspect of the clavicle.
FIGURE 1. Radiograph of right shoulder, anteroposterior view. The arrow shows fracture at the distal end of the clavicle.
severe pain 2 cm medial to the distal end of his right clavicle. He showed severe guarding with any motion of his shoulder and had extreme pain at 90° of forward flexion. Neer and Hawkins testing caused him significant discomfort and pain. Passive cross-body adduction also caused severe pain. The findings on examination of his contralateral shoulder were normal. Radiographs showed evidence of a fracture approximately 3 cm medial to the distal end of the clavicle (Fig 1). There was also evidence of a type II acromion. Given the unclear mechanism for the distal clavicle fracture, magnetic resonance imaging (MRI) and computed tomography (CT) were performed to evaluate the extent of injury. The MRI scan showed a comminuted fracture of the distal clavicle with surrounding bone and soft-tissue edema and an edematous change at the insertion of the rotator cuff consistent with tendinosis. The CT scan confirmed a comminuted fracture of the distal clavicle (Fig 2). Initial management consisted of work restriction and sling immobilization. The patient was encouraged to perform gentle range-of-motion exercises. At 6 weeks’ follow-up after our initial assessment and 10 weeks after shoulder arthroscopy, he continued to have severe discomfort and tenderness at the fracture site. Repeat radiographs showed evidence of slight callus formation (Fig 3). Four months after shoulder
arthroscopy, the patient continued to have significant distal clavicle tenderness with no improvement in symptoms. He also had significant posterior girdle shoulder tenderness and supraspinatus atrophy of his right shoulder. Repeat radiographs at that time showed significant callus formation at the fracture site (Fig 4). The patient began an aggressive physical therapy program with continued work restrictions.
FIGURE 3. Anteroposterior radiograph of right shoulder. The arrow shows callus formation at the distal aspect of the clavicle.
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FIGURE 6. Right shoulder, coronal CT view. The arrow shows callus formation on the superior aspect of the AC joint.
FIGURE 4. Anteroposterior radiograph of right shoulder. The arrow shows significant callus formation at the distal aspect of the clavicle.
At 6 months’ follow-up after the patient’s initial shoulder surgery, he continued to show no improvement in shoulder pain, and a significant lack of internal and external rotation developed. His range of motion was limited by pain to 85° of abduction and forward flexion, external rotation to 15° at his side, and internal rotation to 25° at his side. He also had moderate atrophy of his periscapular musculature and rotator cuff. Repeat radiographs showed significant
FIGURE 5. Anteroposterior radiograph of right shoulder. The arrow shows significant callus formation and a high-riding clavicle.
callus formation at the fracture site of the distal clavicle and evidence of a high-riding distal end of the clavicle approximately 8 mm cephalad to the acromion (Fig 5). As a result of his continued symptoms and development of adhesive capsulitis, the patient was given a subacromial injection to help decrease inflammation and allow more time for bony union of the fracture site. He had no relief of symptoms and was seen at 8 months after the initial surgery, when repeat radiographs and a CT scan were obtained, which showed evidence of consolidation at the fracture site (Fig 6). Given the patient’s unremitting symptoms and evidence of adhesive capsulitis despite a radiographically healed distal clavicle fracture, we recommended a shoulder arthroscopy with revision subacromial decompression, revision distal clavicle resection, and capsular release with lysis of adhesions. On diagnostic arthroscopy, he was found to have grade II chondral changes in the glenoid, tenosynovitis of the biceps, and a frayed superior labrum. During subacromial decompression, the coracoacromial ligament was noted to be frayed and was resected from the acromion. This uncovered a large anterolateral subacromial spur and associated fraying on the bursal side of the rotator cuff. This spur was then resected (Fig 7). Extensive synovitis and degeneration were noted at the AC joint. Visualization of the AC joint showed previous iatrogenic bone loss from burring. The terminal 1 cm of the distal clavicle was resected (Fig 8). Four months after surgery, the patient had shoulder motion of 160° in forward flexion, 162° in abduction, 78° of external rotation with the arm ab-
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FIGURE 7. Arthroscopic view of acromion from posterior portal in right shoulder. The shaver introduced from the lateral working portal and the subacromial spur on the anterolateral acromion should be noted.
ducted, and internal rotation to the L1 level. He also had a dramatic reduction in shoulder pain at the distal clavicle. Six months postoperatively, he has returned to all desired activities including his occupation as a drill-press operator. DISCUSSION The distal clavicle can be resected by either open or arthroscopic technique.11,12 Recently, arthroscopic resection of the distal clavicle has gained in popularity with its potential for decreased morbidity, reduced intraoperative blood loss, improved cosmesis, and reduced postoperative pain.5,13 To our knowledge, this is the first reported case in the literature of a distal clavicle fracture as a complication of shoulder arthroscopy. In this case union was delayed, the patient continued to have pain, and adhesive capsulitis subsequently developed. This initial report of distal clavicle fracture as a possible complication of the arthroscopic Mumford procedure underscores the importance of proper identification of the AC joint before performing an arthroscopic distal clavicle resection. In this report the initial surgeon likely failed to accurately identify the AC joint and subsequently burred the distal 2 cm of the clavicle, causing a distal clavicle fracture. This complication highlights the importance of proper identification of the AC joint before performing a distal clavicle resection. The surgeon can attain proper visualization of the AC joint from the posterior portal after careful resection of the coracoacromial ligament
in a lateral-to-medial direction with a radiofrequency device. After thorough soft-tissue debridement, the surgeon can palpate the distal clavicle and provide an inferiorly directed force to visualize translation of the clavicle at the AC joint. This technique can assist the surgeon in properly identifying the AC joint and, specifically, the distal clavicle before resection. In addition to careful identification of the AC joint, the surgeon should preoperatively determine the potential for distal clavicle pathology before resection. Preoperative MRI films of our patient showed increased AC joint arthrosis and distal clavicle edema. He may have had pre-existing nontraumatic osteolysis of the distal clavicle due to repetitive lifting or microtrauma, thus predisposing him to iatrogenic distal clavicle trauma during arthroscopic burring. Multiple studies have described nontraumatic osteolysis of the distal clavicle associated with repetitive heavy lifting of objects.14-17 Another proposed mechanism of osteolysis suggests that repeated stresses on subchondral bone result in microfracture and subsequent bone resorption.14,18 Increased signal in the AC joint and distal clavicle in this patient suggests a significant traumatic load generated through the distal clavicle and into the AC joint. This finding highlights the importance of proper identification of the AC joint during arthroscopic distal clavicle resection. Post-traumatic osteoarthritis and symptomatic nonunion are potential sequelae from nonoperative treatment of distal clavicle fractures. Distal clavicle fractures account for 50% of all cases of nonunion in clavicle fractures.1 This high rate of nonunion is considered to result from the high number of muscular
FIGURE 8. Arthroscopic view of AC joint from posterior portal in right shoulder. The shaver introduced from the lateral working portal and the distal end of the clavicle (asterisk) should be noted.
DISTAL CLAVICLE FRACTURE forces that act on the shoulder girdle, preventing adequate bony contact necessary to progress to union. With increased delay to union and continued pain at the distal clavicle fracture site, debilitating adhesive capsulitis developed in our patient.19 Although the nonunion rate of distal clavicle fractures has been reported to be as high as 30%,2 adhesive capsulitis has not been described as a complication of distal clavicle fracture. In this case adhesive capsulitis occurred in the patient because he was unable to pursue aggressive physical therapy because of debilitating clavicular pain. In cases of distal clavicle fractures leading to painful nonunion or AC joint arthritis, distal clavicle resection can provide good results.20 At 6 months’ follow-up, our patient has noted significant improvement in pain and function of his affected shoulder. Other potential causes of this fracture, such as an anatomic variant or unfused epiphysis, were also investigated. Radiography of both shoulders was performed, and no evidence was found to confirm the presence of an unfused distal clavicle epiphysis in the contralateral shoulder. Another potential source of preexisting bone weakness is tumor or metabolic disease. Distal clavicle fractures should be considered as a potential complication of misidentification of the AC joint and subsequent aggressive burring of the distal clavicle during shoulder arthroscopy. Special care must be taken to properly identify the AC joint and rule out pre-existing distal clavicle stress fracture or osteolysis before performing the arthroscopic Mumford procedure. Similar to traumatic fractures of the distal clavicle, iatrogenic fractures of the distal clavicle are at risk of delayed union and persistent symptoms and complications including adhesive capsulitis. Operative resection of the distal clavicle should prove to be successful if conservative management of this injury fails. REFERENCES 1. Checchia SL, Doneux PS, Miyazaki AN, Fregoneze M, Silva LA. Treatment of distal clavicle fractures using an arthroscopic technique. J Shoulder Elbow Surg 2008;17:395-398.
933
2. Neer CS II. Fracture of the distal clavicle with detachment of the coracoclavicular ligaments in adults. J Trauma 1963;3:99110. 3. Heppenstall RB. Fractures and dislocations of the distal clavicle. Orthop Clin North Am 1975;6:477-486. 4. Allman FL Jr. Fractures and ligamentous injuries of the clavicle and its articulation. J Bone Joint Surg Am 1967;49:774784. 5. Flatow EL, Duralde XA, Nicholson GP, Pollock RG, Bigliani LU. Arthroscopic resection of the distal clavicle with a superior approach. J Shoulder Elbow Surg 1995;4:41-50. 6. Gartsman GM. Arthroscopic resection of the acromioclavicular joint. Am J Sports Med 1993;21:71-77. 7. Kay SP, Ellman H, Harris E. Arthroscopic distal clavicle excision. Technique and early results. Clin Orthop Relat Res 1994:181-184. 8. Bigliani LU, Nicholson GP, Flatow EL. Arthroscopic resection of the distal clavicle. Orthop Clin North Am 1993; 24:133-141. 9. Edwards SL, Wilson NA, Flores SE, Koh JL, Zhang LQ. Arthroscopic distal clavicle resection: A biomechanical analysis of resection length and joint compliance in a cadaveric model. Arthroscopy 2007;23:1278-1284. 10. Rabalais RD, McCarty E. Surgical treatment of symptomatic acromioclavicular joint problems: A systematic review. Clin Orthop Relat Res 2007;455:30-37. 11. Chronopoulos E, Gill HS, Freehill MT, Petersen SA, McFarland EG. Complications after open distal clavicle excision. Clin Orthop Relat Res 2008;466:646-651. 12. Freedman BA, Javernick MA, O’Brien FP, Ross AE, Doukas WC. Arthroscopic versus open distal clavicle excision: Comparative results at six months and one year from a randomized, prospective clinical trial. J Shoulder Elbow Surg 2007;16:413418. 13. Snyder SJ, Banas MP, Karzel RP. The arthroscopic Mumford procedure: An analysis of results. Arthroscopy 1995;11:157164. 14. Cahill BR. Atraumatic osteolysis of the distal clavicle. A review. Sports Med 1992;13:214-222. 15. Cahill BR. Osteolysis of the distal part of the clavicle in male athletes. J Bone Joint Surg Am 1982;64:1053-1058. 16. Scavenius M, Iversen BF. Nontraumatic clavicular osteolysis in weight lifters. Am J Sports Med 1992;20:463-467. 17. Schwarzkopf R, Ishak C, Elman M, Gelber J, Strauss DN, Jazrawi LM. Distal clavicular osteolysis: A review of the literature. Bull NYU Hosp Jt Dis 2008;66:94-101. 18. Kaplan PA, Resnick D. Stress-induced osteolysis of the clavicle. Radiology 1986;158:139-140. 19. Tauro JC, Paulson M. Shoulder stiffness. Arthroscopy 2008; 24:949-955. 20. Shellhaas JS, Glaser DL, Drezner JA. Distal clavicular stress fracture in a female weight lifter: A case report. Am J Sports Med 2004;32:1755-1758.