- Email: [email protected]
Outcome of glenoid neck fractures
Outcome of glenoid neck fractures Alistair M. Pace, MD, MRCS,a Ranald Stuart, MBChB, FRCR,b and Harry Brownlow, MD, FRCS,a Reading, England
The aim of this study was to analyze the outcome of extraarticular glenoid neck fractures with respect to glenoid neck malunion and rotator cuff injury. These fractures are often considered to have a favorable outcome if treated conservatively. More recent studies reveal that the outcome is not uniformly good, but the cause of poor outcomes has not been investigated. Our study identified 9 patients who had sustained a glenoid neck fracture of the scapula within the last 10 years and who were treated conservatively with immobilization and then early active motion. Their functional and anatomic outcomes were analyzed by clinical examination and validated scoring systems, including the Oxford questionnaire and Constant score. Plain radiography and magnetic resonance imaging were correlated to outcome. None of the 9 patients were pain-free, and some had poor Oxford and Constant scores. Pain was associated with glenoid neck malunion and evidence of subacromial bursitis or rotator cuff tendinopathy (or both). (J Shoulder Elbow Surg 2005;14:585-590.)
F
ractures of the scapula comprise 1% of all fractures. They are rare because of both the well-endowed muscular envelope in which the scapula lies and the mobility of the scapula on the thoracic cage. Fractures of the glenoid neck are the second most common scapular injury and usually result from direct trauma. They are extraarticular and lie within metaphyseal bone. The fracture fragment that contains the glenoid is usually displaced distally and laterally by the pull of the long head of the triceps muscle. The common fracture pattern of the glenoid anatomic neck runs from the lateral border to the superior border of the scapula, lateral to the coracoid process. The difference between an anatomic (lateral to coracoid) and From the aReading Shoulder Unit, Department of Trauma and Orthopaedics, and bDepartment of Radiology, Royal Berkshire Hospital. Reprint requests: Alistair M. Pace, MD, MRCS, Flat 20, Millcroft Park, 322, Frankby Road, Greasby, Wirral, CH 49 3 PE (E-mail: [email protected]). Copyright © 2005 by Journal of Shoulder and Elbow Surgery Board of Trustees. 1058-2746/2005/$30.00 doi:10.1016/j.jse.2005.03.004
surgical (medial to coracoid) scapular neck fracture may not have clinical significance in terms of prognosis and treatment.3 Periarticular metaphyseal fractures tend to heal well because they are situated within vascularized cancellous bone. Attempts are usually made to ensure that these fractures heal with good alignment with respect to the neighboring joint, in order to avoid problems of altered range of motion and altered lines of force, which may precipitate osteoarthritis. Glenoid neck fractures are usually treated nonoperatively because the universal shoulder joint is assumed to be able to accommodate malunion, and the incidence of secondary osteoarthritis in the joint is low. Many reports have concluded that almost all scapular fractures, except displaced intraarticular injuries, have good outcomes.7 However, a more critical analysis has revealed that the results of glenoid neck fractures are not universally good, with a 20% incidence of reduced range of motion, 50% incidence of pain, and 45% incidence of pain and weakness during exertion, especially in abduction.1 A poorer clinical outcome has also been shown with severe glenoid rotational displacement; the reason for poor outcomes has not been properly investigated, being attributed only to malalignment of the scapular neck based solely on plain radiographs in the anteroposterior plane.11 We hypothesized that there may be several reasons for the poor outcome of glenoid neck fractures, including rotator cuff tears, muscle scarring, denervation, and malalignment (rotational and shortening) of the glenoid neck. We, therefore, aimed to review all patients who had sustained a glenoid neck fracture, at least 1 year after injury, and to apply a validated functional outcome measure combined with plain radiography and magnetic resonance imaging (MRI) to exclude rotator cuff tears, to seek evidence of denervation and muscle scarring, and to measure malalignment of the glenoid neck in an attempt to clarify the outcome of nonoperatively treated extraarticular glenoid neck fractures. MATERIALS AND METHODS A cohort study with cases collected by retrospective review of the notes and radiographs of all patients with scapular fractures between 1994-2002 at the Royal Berk-
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Figure 1 Anteroposterior radiograph of shoulder showing GPA ().
shire Hospital, Reading, England, identified 12 patients. A number of inclusion and exclusion criteria for entry into this study were applied. Inclusion criteria were as follows: skeletally mature, at least 1 year since injury, nonoperative treatment (all patients in our study were treated with immobilization of the shoulder in a sling, in internal rotation and adduction for 6 weeks, followed by early active mobilization with physiotherapy), willingness to participate in the study, and ability to understand English. The exclusion criterion was pre-existing ipsilateral shoulder pathology. The research study was fully approved by the local research and ethics committee. The patients were asked to sign a consent form before participation in the study, and their general practitioner was informed. The Oxford questionnaire5 and the Constant score4 were used as validated functional outcome scores. Pain scores were completed during periods of rest, work, and sport. Patients were also asked about their general satisfaction with the outcome of treatment. The patients were examined clinically, and the range of movements in both shoulders was determined with a goniometer. Evidence of deformity, muscular atrophy, and subscapular crepitus was noted. The strength of the supraspinatus and infraspinatus was determined with a Nottingham myometer. Radiographs of both shoulders were obtained in the anteroposterior, lateral Y, and axillary projections. MRI of the shoulders was performed with a 1.5-T scanner (Gyroscan Intera; Philips Medical Systems, Best, The Netherlands) with a phased-array shoulder coil. The following pulse sequences were used: coronal T1-weighted, coronal proton density, coronal T2-weighted with fat saturation, and sagittal and axial proton density with fat saturation. All radiologic investigations were interpreted by a radiologist with a specialized interest in musculoskeletal radiology; the
Figure 2 Axillary radiograph of shoulder showing glenoid version angle (␣).
radiologist was blinded to the clinical outcome measures. MRI documented the integrity of the rotator cuff and the presence of subacromial/subdeltoid bursitis, with assessment of the acromion, coracoacromial ligament, and acromioclavicular joint; the congruity at the glenohumeral articulation and gross glenoid labral anatomy were also assessed, with further consideration of potential denervation change and muscle atrophy. Scapular neck length was measured from the most lateral point of the glenoid rim to the most medial point of the scapular spine as seen on an axial view through that region. Radiographs were used to determine the glenopolar angle (GPA) and glenoid version as follows. Rotational malalignment of the glenoid neck in the coronal plane of the scapula was measured by assessing the GPA on an anteroposterior plain radiograph (Figure 1). The GPA provides a value for the obliquity of the glenoid articular surface in relation to the scapular body in the plane of the scapula. According to McAdams et al, a GPA ranging from 30° to 45° is considered normal and angles less than 20° imply severe glenoid rotational malalignment.8 Glenoid version was determined by drawing a line between the anterior and posterior margins of the glenoid as visualized on axillary views. The relationship between this line and the perpendicular to the transverse axis of the scapula (a line drawn from the midpoint of the glenoid fossa to the medial edge of the scapula) determined glenoid
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Table I Patient Characteristics Pain Time (out of 8) since ConstantPatient Age injury Injury Dominant Oxford Murley No. (y) (mo) Rest ADL Work Night Sports score* ABD side side score† 1 2 3 4 5 6 7 8 9
21 30 29 37 39 26 51 44 64
24 96 72 72 72 60 36 60 24
L R R R L R R R R
R R L R R R R R R
0 1 1 0 1 0 0 4 6
3 1 0 0 0 2 0 4 8
4 2 0 3 1 2 1 4 8
2 0 0 0 0 0 0 0 5
3 0 0 3 0 — 1 — 4
20 21 20 20 18 16 14 26 24
67 79 86 68 78 67 81 46 29
170 165 175 160 180 180 180 90 95
ROM (°) FF
Strength (as measured on myometer) ER
Supraspinatus Infraspinatus LR (normal/abnormal) (normal/abnormal)
175 75 90 180 60 70 180 95 90 165 80 90 180 100 90 180 100 90 180 100 90 170 80 80 120 40 45
10.3/8.5 18.1/16.3 11.5/11.8 9.1/8.5 11.3/7.8 8/4.1 10.4/10.7 11.1/12.2 6.8/4.2
12.4/11.5 15.2/14.2 13/12.3 7.4/7.9 8.3/5.14 10/10.4 11.2/10.9 9.6/9.2 8/5.3
ADL, Activities of daily living; ROM, range of motion; ABD, abduction; FF, forward flexion; ER, external rotation; IR, internal rotation; E, excellent; G, good; F, fair; P, poor; OA, osteoarthritis. *A validated scoring system including 12 questions relating to pain and everyday actions involving the shoulder joint (scored 1-5). The score from each question is added up to give the final score. The minimum score of 12 implies the least difficulty in shoulder function, and the most difficulty is denoted by a score of 60. †A validated scoring system including 5 questions relating to pain, activity level, arm postion, range of movement (forward flexion, lateral elevation, external and internal rotation), and strength of abduction. The scores for each question are added up to give the final score.
version (Figure 2); this was best assessed on axillary radiographs.2
some disability in normal activity because of shoulder pain, with significant disability in one of these.
RESULTS
Range of movement
Demographics
One patient refused to participate in the study, one was untraceable, and one refused to undergo MRI. This, therefore, left 9 patients from the original cohort of 12. All were men ranging in age from 21 to 64 years. The mean age was 34 years. There were 7 right and 2 left glenoid neck fractures, and all cases were unilateral and closed. Six were related to motorcycle accidents, two were pedestrian accidents, and one was the result of a fall from a height. Three patients had associated facial and head injuries, and three had associated chest injuries with rib and clavicle fractures, the latter requiring open reduction and internal fixation of the clavicle fracture. One patient had an associated tibia and fibula fracture. All of the scapular neck fractures progressed to clinical and radiologic union. Pain, activities of daily living, and sports
None of the 9 patients were completely free of pain. Five had pain at rest; three had mild pain, but two reported moderate rest pain. Eight of nine patients reported little or mild pain with severe exertion, and two reported pain affecting their daily work. With regard to employment and hobbies, 3 patients performed these activities easily, 4 reported little difficulty, 1 reported moderate difficulty (mostly while lifting weights), and 1 reported extreme difficulty. Of the 7 patients who played sports, 3 reported moderate disability. Six of nine patients reported
Generally, the range of movement was well preserved, with only 1 patient demonstrating a global restriction of movement (patient 9). This patient had evidence of glenohumeral osteoarthritis. One patient had restricted abduction because of pain but wellpreserved forward flexion and rotation (patient 8). Strength testing
Isokinetic strength measurement in the supraspinatus and infraspinatus as measured by myometer is shown in Table I. Three patients had a greater than 25% loss of power in the supraspinatus muscle compared with the other side. Patient 9 had the worst range of movement and strength, but he was the oldest patient and had evidence of osteoarthritis in the glenohumeral joint. Patient 6 had weak abduction and evidence of subacromial bursitis. Patient 5 had weak abduction and external rotation but had full range of movement and only minor tendinopathic changes. Radiologic findings
The GPA measurement reflects alteration of the glenoid position in a caudal-cranial direction. The results are shown in Table II. One subject (patient 9) had evidence of moderate osteoathrosis with incongruency of the glenoid surface on radiographs. Four patients thus had significantly altered version, three had a significantly al-
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Table I Patient Characteristics Glenoid version (0 ⴝ neutral)
Glenoid neck length
GPA
Scapular length
Outcome satisfaction
Normal side
Abnormal side
Normal side
Abnormal side
Normal side
Abnormal side
Normal side
Abnormal side
G G E G E G E F P
0 0 5 –19 0 0 0 0 –5
–3 1 –10 –12 0 –1 0 –7 –15
20 21 21 20 20 19 19 24 21
22 23 23 20 20 19 19 19 23
50 41.5 42.3 45.2 30.4 38.5 39.5 26.1 33.4
44 33.9 42.7 45 31 38.9 36.7 10.2 30.0
116 109 118 112 115 107 117 113 108
115 102 111 104 110 108 118 105 101
tered GPA, and six had a significant change in the scapular length compared with the normal side. MRI findings
MRI revealed that there were no rotator cuff tears, atrophy, or denervation changes, but 7 of 9 patients had evidence of subacromial bursitis or tendinopathy (or both) and 1 patient had an osseous Bankart lesion with a healed Hill-Sachs lesion and glenohumeral osteoarthritis. There was acromioclavicular arthritis in 5 patients, which was classified as minor in 4 and moderate in 1. Minor acromioclavicular joint osteoarthritis is known to be present in 90% of persons aged older than 30 years.12 DISCUSSION The high number of severe injuries accompanying scapular fractures, mainly of the ipsilateral lung and chest wall and the ipsilateral shoulder girdle, is adequately documented in the literature. Fracture treatment of the scapula assures a low precedence in the severely injured patient.3 The management of these fractures is usually nonoperative, with treatment aimed at symptom relief and early motion to prevent stiffness, rehabilitation of the rotator cuff, and strengthening of the periscapular musculature. Data have now been attained about injury characteristics that may portend a poor prognosis, shedding light on potential indications for surgery. Previously, surgical treatment has been recommended for displaced intraarticular fractures and associated clavicular fractures and acromioclavicular joint dislocations. Ada and Miller1 have recommended operative treatment of scapular neck fractures if (1) the glenoid is medially displaced by more than 9 mm, (2) there is more than 40° of angular displacement, (3) 100% translation of the lateral border is present, and (4) there is associated double disruption of the superior shoulder suspensory complex, comprising the glenoid cavity, coracoid pro-
MRI changes Subacromial bursitis Subacromial bursitis, minor tendonopathy Subacromial bursitis, minor acromioclavicular OA Minor tendonopathy, minor acromioclavicular OA Minor tendonopathy, minor acromioclavicualar OA Subacromial busitis, Minor acromioclavicular OA Subacromial bursitis, minor tendonopathy Moderate acromioclavicular OA, osseous Bankart lesion, and Hill-Sachs lesion
cess, coracoclavicular ligaments, acromioclavicular joint, and acromion linkage. Considering the results obtained in this study, a maximum of 8 mm of medial displacement of the glenoid compared with the normal side was obtained. In addition, there was no patient categorized as having more than 40° angular displacement or 100% translation. Consequently, according to Ada and Miller,1 surgery would not be recommended in our cohort of patients. However, it must be emphasized that these criteria are not absolute and must be placed in the context of the patient’s age, activity demands, and extremity dominance. In 1984 Hardegger et al6 documented that 79% of patients with glenoid neck fractures treated operatively achieved excellent results, although this was based on the surgical opinion rather than a validated outcome measure. Ada and Miller1 reported on the follow-up of 16 patients with displaced scapular neck fractures treated conservatively; 50% had pain, 40% had exertional weakness involving abduction-type activity, and 20% had decreased motion. The most common site of discomfort was in the subacromial space, and this was especially noted in patients complaining of night pain when lying on the affected side. Similarly, Nordqvist and Petersson10 showed that residual stiffness developed after 6 months in 50% of patients with displaced scapular fractures treated conservatively. In contrast to all of the above studies, this investigation incorporated an independent observer, validated outcome measures, and objective tests of strength and included modern imaging techniques. We concur with Ada and Miller1 that patients with extraarticular glenoid neck fractures treated conservatively have a high incidence of residual pain (100%) and some have residual weakness (33%), but we found that all, except the patient with glenohumeral osteoarthritis, had a good range of motion. The cause of the pain and weakness does not appear to be related to neurologic deficit, muscle atrophy, or
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Table II Measurement results
Patient No.
Glenoid version: >5° difference between sides
GPA: >5° difference between sides
Scapular length: >5-mm difference between sides
1 2 3 4 5 6 7 8 9
No No Yes Yes No No No Yes Yes
Yes Yes No No No No No Yes No
No Yes Yes Yes Yes No No Yes Yes
One subject (patient 9) had evidence of moderate osteoathrosis with incongruency of the glenoid surface on x-ray four patients thus had significantly altered version, 3 had a significantly altered glenopolar angle, and 6 had a significant change in the scapular length compared to the normal side.
rotator cuff tear but is probably a result of rotator cuff dysfunction. All but 1 patient had MRI for evidence of subacromial bursitis or minor tendinopathy (or both). Seven of eight patients also had evidence of glenoid neck malunion. The only 2 patients without radiologic evidence of glenoid neck malunion had the best Oxford scores, full range of motion, and good or excellent outcomes. All of the other patients had glenoid malunion, together with bursitis or tendinopathy (or both) and worse outcome scores. We hypothesize that the rotator cuff dysfunction is a consequence of glenoid neck malunion, which alters the normal lever arm of the rotator cuff and, therefore, decreases the mechanical advantage of the muscles of the rotator cuff. With increasing tilt and abnormal version of the glenoid, the normal glenohumeral compressive force of the rotator cuff is transformed to a shearing force. The results show that there is no correlation between the time of injury and clinical outcome, with excellent outcomes being found in patients examined after 36 and 72 months, good results in patients examined after 24 to 96 months, and fair results in those seen 5 years after injury, as well as a patient reporting poor results 2 years after injury. There was also poor correlation with measuring Constant-Murley scores, with high scores being obtained in patients 72 months as well as 36 months after injury. Lower scores were reported in patients examined after 24 months and 60 months. Oxford scores similarly correlated poorly with time of injury, with low scores being found in patients examined after 60 and 72 months and high scores at 24 months after injury. Fractures of the surgical neck may be associated with severe displacement of the lateral scapular angle. The amount of displacement is dependent on whether there is an associated fracture of the clavicle, coracoclavicular ligamentous disruption, or both. If the clavicle and these ligaments are intact, the fracture remains stable. If, however, the suspensory and stabilizing functions of these structures are lost, the
neck fragment becomes unstable because muscle forces and the weight of the arm pull it distally and anteromedially. The relationship of the glenohumeral joint with the acromion and the nearby muscle origins is altered, resulting in functional imbalance. The cases of patients with abnormal degrees of retroversion or scapular length shortening were associated with a decreased range of movement and decreased rotator cuff power. Neviaser9 hypothesized that the function of the rotator cuff was adversely affected in scapular fractures as a result of hemorrhage into the periscapular musculature causing temporary paralysis. However, in our study, there was no evidence of muscle atrophy or scarring, but all patients had some evidence of tendinopathic change and bursitis, which could have arisen as a result of muscle trauma or altered alignment. We do not know whether correction of malunion may improve long-term results, but patients could conceivably be helped by steroid injections or acromioplasty. This study confirms that the outcome of glenoid neck fractures treated conservatively is generally good, with 90% of patients achieving good or excellent satisfaction levels. However, the majority of patients have some activity-related pain, which correlates with MRI evidence of subacromial impingement and minor cuff tendinopathy, which in turn seems to be associated with glenoid neck malunion. We thank the Radiology Department staff in the MRI Unit, Royal Berkshire Hospital. REFERENCES
1. Ada JR, Miller ME. Scapular fractures. Analysis of 113 cases. Clin Orthop Relat Res 1991;269:174-80. 2. Churchill RS, Brems JJ, Kotschi H. Glenoid size, inclination, and version: an anatomic study. J Shoulder Elbow Surg 2001;10: 327-32. 3. Cole PA. Scapular fractures. Orthop Clin North Am 2002;33: 1-18.
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4. Constant CR, Murley AH. A clinical method of functional assessment of the shoulder. Clin Orthop Relat Res 1987;214:160-4. 5. Dawson J, Carr A. Questionnaire on the perceptions of patients about shoulder surgery. J Bone Joint Surg Br 1996;78:593-600. 6. Hardegger FH, Simpson LA, Weber BG. The operative treatment of scapular fractures. J Bone Joint Surg Br 1984;66:725-31. 7. Herscovici D, Gregory P, Sanders R. Injuries of the shoulder girdle. Clin Orthop Relat Res 1995;318:54-60. 8. McAdams TR, Blevins FT, Martin TP, DeCoster TA. The role of plain films and computed tomography in the evaluation of scapular neck fractures. J Orthop Trauma 1996;16:7-11.
J Shoulder Elbow Surg November/December 2005
9. Neviaser JS. Traumatic lesions; injuries in and about the shoulder joint. Instr Course Lect 1956;13:187-216. 10. Nordqvist A, Petersson C. Fracture of the body, neck, or spine of the scapula. A long-term follow-up study. Clin Orthop Relat Res 1992;283:139-44. 11. Romero JP, Imhoff SAB. Scapular neck fracture—the influence of permanent malalignment of the glenoid neck on clinical outcome. Arch Orthop Trauma Surg 2001;121:313-6. 12. Sun P, Mahakkamukraum P. Prevalence of osteophytes associated with the acromion and acromioclavicular joint. Clin Anat 2003;16:506-10.
The aim of this study was to analyze the outcome of extraarticular glenoid neck fractures with respect to glenoid neck malunion and rotator cuff injury. These fractures are often considered to have a favorable outcome if treated conservatively. More recent studies reveal that the outcome is not uniformly good, but the cause of poor outcomes has not been investigated. Our study identified 9 patients who had sustained a glenoid neck fracture of the scapula within the last 10 years and who were treated conservatively with immobilization and then early active motion. Their functional and anatomic outcomes were analyzed by clinical examination and validated scoring systems, including the Oxford questionnaire and Constant score. Plain radiography and magnetic resonance imaging were correlated to outcome. None of the 9 patients were pain-free, and some had poor Oxford and Constant scores. Pain was associated with glenoid neck malunion and evidence of subacromial bursitis or rotator cuff tendinopathy (or both). (J Shoulder Elbow Surg 2005;14:585-590.)
F
ractures of the scapula comprise 1% of all fractures. They are rare because of both the well-endowed muscular envelope in which the scapula lies and the mobility of the scapula on the thoracic cage. Fractures of the glenoid neck are the second most common scapular injury and usually result from direct trauma. They are extraarticular and lie within metaphyseal bone. The fracture fragment that contains the glenoid is usually displaced distally and laterally by the pull of the long head of the triceps muscle. The common fracture pattern of the glenoid anatomic neck runs from the lateral border to the superior border of the scapula, lateral to the coracoid process. The difference between an anatomic (lateral to coracoid) and From the aReading Shoulder Unit, Department of Trauma and Orthopaedics, and bDepartment of Radiology, Royal Berkshire Hospital. Reprint requests: Alistair M. Pace, MD, MRCS, Flat 20, Millcroft Park, 322, Frankby Road, Greasby, Wirral, CH 49 3 PE (E-mail: [email protected]). Copyright © 2005 by Journal of Shoulder and Elbow Surgery Board of Trustees. 1058-2746/2005/$30.00 doi:10.1016/j.jse.2005.03.004
surgical (medial to coracoid) scapular neck fracture may not have clinical significance in terms of prognosis and treatment.3 Periarticular metaphyseal fractures tend to heal well because they are situated within vascularized cancellous bone. Attempts are usually made to ensure that these fractures heal with good alignment with respect to the neighboring joint, in order to avoid problems of altered range of motion and altered lines of force, which may precipitate osteoarthritis. Glenoid neck fractures are usually treated nonoperatively because the universal shoulder joint is assumed to be able to accommodate malunion, and the incidence of secondary osteoarthritis in the joint is low. Many reports have concluded that almost all scapular fractures, except displaced intraarticular injuries, have good outcomes.7 However, a more critical analysis has revealed that the results of glenoid neck fractures are not universally good, with a 20% incidence of reduced range of motion, 50% incidence of pain, and 45% incidence of pain and weakness during exertion, especially in abduction.1 A poorer clinical outcome has also been shown with severe glenoid rotational displacement; the reason for poor outcomes has not been properly investigated, being attributed only to malalignment of the scapular neck based solely on plain radiographs in the anteroposterior plane.11 We hypothesized that there may be several reasons for the poor outcome of glenoid neck fractures, including rotator cuff tears, muscle scarring, denervation, and malalignment (rotational and shortening) of the glenoid neck. We, therefore, aimed to review all patients who had sustained a glenoid neck fracture, at least 1 year after injury, and to apply a validated functional outcome measure combined with plain radiography and magnetic resonance imaging (MRI) to exclude rotator cuff tears, to seek evidence of denervation and muscle scarring, and to measure malalignment of the glenoid neck in an attempt to clarify the outcome of nonoperatively treated extraarticular glenoid neck fractures. MATERIALS AND METHODS A cohort study with cases collected by retrospective review of the notes and radiographs of all patients with scapular fractures between 1994-2002 at the Royal Berk-
585
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Figure 1 Anteroposterior radiograph of shoulder showing GPA ().
shire Hospital, Reading, England, identified 12 patients. A number of inclusion and exclusion criteria for entry into this study were applied. Inclusion criteria were as follows: skeletally mature, at least 1 year since injury, nonoperative treatment (all patients in our study were treated with immobilization of the shoulder in a sling, in internal rotation and adduction for 6 weeks, followed by early active mobilization with physiotherapy), willingness to participate in the study, and ability to understand English. The exclusion criterion was pre-existing ipsilateral shoulder pathology. The research study was fully approved by the local research and ethics committee. The patients were asked to sign a consent form before participation in the study, and their general practitioner was informed. The Oxford questionnaire5 and the Constant score4 were used as validated functional outcome scores. Pain scores were completed during periods of rest, work, and sport. Patients were also asked about their general satisfaction with the outcome of treatment. The patients were examined clinically, and the range of movements in both shoulders was determined with a goniometer. Evidence of deformity, muscular atrophy, and subscapular crepitus was noted. The strength of the supraspinatus and infraspinatus was determined with a Nottingham myometer. Radiographs of both shoulders were obtained in the anteroposterior, lateral Y, and axillary projections. MRI of the shoulders was performed with a 1.5-T scanner (Gyroscan Intera; Philips Medical Systems, Best, The Netherlands) with a phased-array shoulder coil. The following pulse sequences were used: coronal T1-weighted, coronal proton density, coronal T2-weighted with fat saturation, and sagittal and axial proton density with fat saturation. All radiologic investigations were interpreted by a radiologist with a specialized interest in musculoskeletal radiology; the
Figure 2 Axillary radiograph of shoulder showing glenoid version angle (␣).
radiologist was blinded to the clinical outcome measures. MRI documented the integrity of the rotator cuff and the presence of subacromial/subdeltoid bursitis, with assessment of the acromion, coracoacromial ligament, and acromioclavicular joint; the congruity at the glenohumeral articulation and gross glenoid labral anatomy were also assessed, with further consideration of potential denervation change and muscle atrophy. Scapular neck length was measured from the most lateral point of the glenoid rim to the most medial point of the scapular spine as seen on an axial view through that region. Radiographs were used to determine the glenopolar angle (GPA) and glenoid version as follows. Rotational malalignment of the glenoid neck in the coronal plane of the scapula was measured by assessing the GPA on an anteroposterior plain radiograph (Figure 1). The GPA provides a value for the obliquity of the glenoid articular surface in relation to the scapular body in the plane of the scapula. According to McAdams et al, a GPA ranging from 30° to 45° is considered normal and angles less than 20° imply severe glenoid rotational malalignment.8 Glenoid version was determined by drawing a line between the anterior and posterior margins of the glenoid as visualized on axillary views. The relationship between this line and the perpendicular to the transverse axis of the scapula (a line drawn from the midpoint of the glenoid fossa to the medial edge of the scapula) determined glenoid
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Table I Patient Characteristics Pain Time (out of 8) since ConstantPatient Age injury Injury Dominant Oxford Murley No. (y) (mo) Rest ADL Work Night Sports score* ABD side side score† 1 2 3 4 5 6 7 8 9
21 30 29 37 39 26 51 44 64
24 96 72 72 72 60 36 60 24
L R R R L R R R R
R R L R R R R R R
0 1 1 0 1 0 0 4 6
3 1 0 0 0 2 0 4 8
4 2 0 3 1 2 1 4 8
2 0 0 0 0 0 0 0 5
3 0 0 3 0 — 1 — 4
20 21 20 20 18 16 14 26 24
67 79 86 68 78 67 81 46 29
170 165 175 160 180 180 180 90 95
ROM (°) FF
Strength (as measured on myometer) ER
Supraspinatus Infraspinatus LR (normal/abnormal) (normal/abnormal)
175 75 90 180 60 70 180 95 90 165 80 90 180 100 90 180 100 90 180 100 90 170 80 80 120 40 45
10.3/8.5 18.1/16.3 11.5/11.8 9.1/8.5 11.3/7.8 8/4.1 10.4/10.7 11.1/12.2 6.8/4.2
12.4/11.5 15.2/14.2 13/12.3 7.4/7.9 8.3/5.14 10/10.4 11.2/10.9 9.6/9.2 8/5.3
ADL, Activities of daily living; ROM, range of motion; ABD, abduction; FF, forward flexion; ER, external rotation; IR, internal rotation; E, excellent; G, good; F, fair; P, poor; OA, osteoarthritis. *A validated scoring system including 12 questions relating to pain and everyday actions involving the shoulder joint (scored 1-5). The score from each question is added up to give the final score. The minimum score of 12 implies the least difficulty in shoulder function, and the most difficulty is denoted by a score of 60. †A validated scoring system including 5 questions relating to pain, activity level, arm postion, range of movement (forward flexion, lateral elevation, external and internal rotation), and strength of abduction. The scores for each question are added up to give the final score.
version (Figure 2); this was best assessed on axillary radiographs.2
some disability in normal activity because of shoulder pain, with significant disability in one of these.
RESULTS
Range of movement
Demographics
One patient refused to participate in the study, one was untraceable, and one refused to undergo MRI. This, therefore, left 9 patients from the original cohort of 12. All were men ranging in age from 21 to 64 years. The mean age was 34 years. There were 7 right and 2 left glenoid neck fractures, and all cases were unilateral and closed. Six were related to motorcycle accidents, two were pedestrian accidents, and one was the result of a fall from a height. Three patients had associated facial and head injuries, and three had associated chest injuries with rib and clavicle fractures, the latter requiring open reduction and internal fixation of the clavicle fracture. One patient had an associated tibia and fibula fracture. All of the scapular neck fractures progressed to clinical and radiologic union. Pain, activities of daily living, and sports
None of the 9 patients were completely free of pain. Five had pain at rest; three had mild pain, but two reported moderate rest pain. Eight of nine patients reported little or mild pain with severe exertion, and two reported pain affecting their daily work. With regard to employment and hobbies, 3 patients performed these activities easily, 4 reported little difficulty, 1 reported moderate difficulty (mostly while lifting weights), and 1 reported extreme difficulty. Of the 7 patients who played sports, 3 reported moderate disability. Six of nine patients reported
Generally, the range of movement was well preserved, with only 1 patient demonstrating a global restriction of movement (patient 9). This patient had evidence of glenohumeral osteoarthritis. One patient had restricted abduction because of pain but wellpreserved forward flexion and rotation (patient 8). Strength testing
Isokinetic strength measurement in the supraspinatus and infraspinatus as measured by myometer is shown in Table I. Three patients had a greater than 25% loss of power in the supraspinatus muscle compared with the other side. Patient 9 had the worst range of movement and strength, but he was the oldest patient and had evidence of osteoarthritis in the glenohumeral joint. Patient 6 had weak abduction and evidence of subacromial bursitis. Patient 5 had weak abduction and external rotation but had full range of movement and only minor tendinopathic changes. Radiologic findings
The GPA measurement reflects alteration of the glenoid position in a caudal-cranial direction. The results are shown in Table II. One subject (patient 9) had evidence of moderate osteoathrosis with incongruency of the glenoid surface on radiographs. Four patients thus had significantly altered version, three had a significantly al-
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Table I Patient Characteristics Glenoid version (0 ⴝ neutral)
Glenoid neck length
GPA
Scapular length
Outcome satisfaction
Normal side
Abnormal side
Normal side
Abnormal side
Normal side
Abnormal side
Normal side
Abnormal side
G G E G E G E F P
0 0 5 –19 0 0 0 0 –5
–3 1 –10 –12 0 –1 0 –7 –15
20 21 21 20 20 19 19 24 21
22 23 23 20 20 19 19 19 23
50 41.5 42.3 45.2 30.4 38.5 39.5 26.1 33.4
44 33.9 42.7 45 31 38.9 36.7 10.2 30.0
116 109 118 112 115 107 117 113 108
115 102 111 104 110 108 118 105 101
tered GPA, and six had a significant change in the scapular length compared with the normal side. MRI findings
MRI revealed that there were no rotator cuff tears, atrophy, or denervation changes, but 7 of 9 patients had evidence of subacromial bursitis or tendinopathy (or both) and 1 patient had an osseous Bankart lesion with a healed Hill-Sachs lesion and glenohumeral osteoarthritis. There was acromioclavicular arthritis in 5 patients, which was classified as minor in 4 and moderate in 1. Minor acromioclavicular joint osteoarthritis is known to be present in 90% of persons aged older than 30 years.12 DISCUSSION The high number of severe injuries accompanying scapular fractures, mainly of the ipsilateral lung and chest wall and the ipsilateral shoulder girdle, is adequately documented in the literature. Fracture treatment of the scapula assures a low precedence in the severely injured patient.3 The management of these fractures is usually nonoperative, with treatment aimed at symptom relief and early motion to prevent stiffness, rehabilitation of the rotator cuff, and strengthening of the periscapular musculature. Data have now been attained about injury characteristics that may portend a poor prognosis, shedding light on potential indications for surgery. Previously, surgical treatment has been recommended for displaced intraarticular fractures and associated clavicular fractures and acromioclavicular joint dislocations. Ada and Miller1 have recommended operative treatment of scapular neck fractures if (1) the glenoid is medially displaced by more than 9 mm, (2) there is more than 40° of angular displacement, (3) 100% translation of the lateral border is present, and (4) there is associated double disruption of the superior shoulder suspensory complex, comprising the glenoid cavity, coracoid pro-
MRI changes Subacromial bursitis Subacromial bursitis, minor tendonopathy Subacromial bursitis, minor acromioclavicular OA Minor tendonopathy, minor acromioclavicular OA Minor tendonopathy, minor acromioclavicualar OA Subacromial busitis, Minor acromioclavicular OA Subacromial bursitis, minor tendonopathy Moderate acromioclavicular OA, osseous Bankart lesion, and Hill-Sachs lesion
cess, coracoclavicular ligaments, acromioclavicular joint, and acromion linkage. Considering the results obtained in this study, a maximum of 8 mm of medial displacement of the glenoid compared with the normal side was obtained. In addition, there was no patient categorized as having more than 40° angular displacement or 100% translation. Consequently, according to Ada and Miller,1 surgery would not be recommended in our cohort of patients. However, it must be emphasized that these criteria are not absolute and must be placed in the context of the patient’s age, activity demands, and extremity dominance. In 1984 Hardegger et al6 documented that 79% of patients with glenoid neck fractures treated operatively achieved excellent results, although this was based on the surgical opinion rather than a validated outcome measure. Ada and Miller1 reported on the follow-up of 16 patients with displaced scapular neck fractures treated conservatively; 50% had pain, 40% had exertional weakness involving abduction-type activity, and 20% had decreased motion. The most common site of discomfort was in the subacromial space, and this was especially noted in patients complaining of night pain when lying on the affected side. Similarly, Nordqvist and Petersson10 showed that residual stiffness developed after 6 months in 50% of patients with displaced scapular fractures treated conservatively. In contrast to all of the above studies, this investigation incorporated an independent observer, validated outcome measures, and objective tests of strength and included modern imaging techniques. We concur with Ada and Miller1 that patients with extraarticular glenoid neck fractures treated conservatively have a high incidence of residual pain (100%) and some have residual weakness (33%), but we found that all, except the patient with glenohumeral osteoarthritis, had a good range of motion. The cause of the pain and weakness does not appear to be related to neurologic deficit, muscle atrophy, or
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Table II Measurement results
Patient No.
Glenoid version: >5° difference between sides
GPA: >5° difference between sides
Scapular length: >5-mm difference between sides
1 2 3 4 5 6 7 8 9
No No Yes Yes No No No Yes Yes
Yes Yes No No No No No Yes No
No Yes Yes Yes Yes No No Yes Yes
One subject (patient 9) had evidence of moderate osteoathrosis with incongruency of the glenoid surface on x-ray four patients thus had significantly altered version, 3 had a significantly altered glenopolar angle, and 6 had a significant change in the scapular length compared to the normal side.
rotator cuff tear but is probably a result of rotator cuff dysfunction. All but 1 patient had MRI for evidence of subacromial bursitis or minor tendinopathy (or both). Seven of eight patients also had evidence of glenoid neck malunion. The only 2 patients without radiologic evidence of glenoid neck malunion had the best Oxford scores, full range of motion, and good or excellent outcomes. All of the other patients had glenoid malunion, together with bursitis or tendinopathy (or both) and worse outcome scores. We hypothesize that the rotator cuff dysfunction is a consequence of glenoid neck malunion, which alters the normal lever arm of the rotator cuff and, therefore, decreases the mechanical advantage of the muscles of the rotator cuff. With increasing tilt and abnormal version of the glenoid, the normal glenohumeral compressive force of the rotator cuff is transformed to a shearing force. The results show that there is no correlation between the time of injury and clinical outcome, with excellent outcomes being found in patients examined after 36 and 72 months, good results in patients examined after 24 to 96 months, and fair results in those seen 5 years after injury, as well as a patient reporting poor results 2 years after injury. There was also poor correlation with measuring Constant-Murley scores, with high scores being obtained in patients 72 months as well as 36 months after injury. Lower scores were reported in patients examined after 24 months and 60 months. Oxford scores similarly correlated poorly with time of injury, with low scores being found in patients examined after 60 and 72 months and high scores at 24 months after injury. Fractures of the surgical neck may be associated with severe displacement of the lateral scapular angle. The amount of displacement is dependent on whether there is an associated fracture of the clavicle, coracoclavicular ligamentous disruption, or both. If the clavicle and these ligaments are intact, the fracture remains stable. If, however, the suspensory and stabilizing functions of these structures are lost, the
neck fragment becomes unstable because muscle forces and the weight of the arm pull it distally and anteromedially. The relationship of the glenohumeral joint with the acromion and the nearby muscle origins is altered, resulting in functional imbalance. The cases of patients with abnormal degrees of retroversion or scapular length shortening were associated with a decreased range of movement and decreased rotator cuff power. Neviaser9 hypothesized that the function of the rotator cuff was adversely affected in scapular fractures as a result of hemorrhage into the periscapular musculature causing temporary paralysis. However, in our study, there was no evidence of muscle atrophy or scarring, but all patients had some evidence of tendinopathic change and bursitis, which could have arisen as a result of muscle trauma or altered alignment. We do not know whether correction of malunion may improve long-term results, but patients could conceivably be helped by steroid injections or acromioplasty. This study confirms that the outcome of glenoid neck fractures treated conservatively is generally good, with 90% of patients achieving good or excellent satisfaction levels. However, the majority of patients have some activity-related pain, which correlates with MRI evidence of subacromial impingement and minor cuff tendinopathy, which in turn seems to be associated with glenoid neck malunion. We thank the Radiology Department staff in the MRI Unit, Royal Berkshire Hospital. REFERENCES
1. Ada JR, Miller ME. Scapular fractures. Analysis of 113 cases. Clin Orthop Relat Res 1991;269:174-80. 2. Churchill RS, Brems JJ, Kotschi H. Glenoid size, inclination, and version: an anatomic study. J Shoulder Elbow Surg 2001;10: 327-32. 3. Cole PA. Scapular fractures. Orthop Clin North Am 2002;33: 1-18.
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4. Constant CR, Murley AH. A clinical method of functional assessment of the shoulder. Clin Orthop Relat Res 1987;214:160-4. 5. Dawson J, Carr A. Questionnaire on the perceptions of patients about shoulder surgery. J Bone Joint Surg Br 1996;78:593-600. 6. Hardegger FH, Simpson LA, Weber BG. The operative treatment of scapular fractures. J Bone Joint Surg Br 1984;66:725-31. 7. Herscovici D, Gregory P, Sanders R. Injuries of the shoulder girdle. Clin Orthop Relat Res 1995;318:54-60. 8. McAdams TR, Blevins FT, Martin TP, DeCoster TA. The role of plain films and computed tomography in the evaluation of scapular neck fractures. J Orthop Trauma 1996;16:7-11.
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9. Neviaser JS. Traumatic lesions; injuries in and about the shoulder joint. Instr Course Lect 1956;13:187-216. 10. Nordqvist A, Petersson C. Fracture of the body, neck, or spine of the scapula. A long-term follow-up study. Clin Orthop Relat Res 1992;283:139-44. 11. Romero JP, Imhoff SAB. Scapular neck fracture—the influence of permanent malalignment of the glenoid neck on clinical outcome. Arch Orthop Trauma Surg 2001;121:313-6. 12. Sun P, Mahakkamukraum P. Prevalence of osteophytes associated with the acromion and acromioclavicular joint. Clin Anat 2003;16:506-10.