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PubMed1993

Shoulder impingement syndrome: diagnosis, radiographic evaluation, and treatment with a modified Neer acromioplasty.

Seventy-one patients who had shoulder impingement syndrome were managed operatively with a modified Neer acromioplasty: thirty-seven, who had an intact rotator cuff, had a modified acromioplasty, and thirty-four, who had a torn cuff, had a modified acromioplasty and repair of the cuff. In the classic anterior acromioplasty as described by Neer, emphasis is placed on resection of the inferior prominence of the acromion. We believe that the removal of only the inferior prominence is insufficient, as often too much of the anterior aspect of the acromion protrudes beyond the anterior border of the clavicle. This portion of the acromion continues to irritate the subacromial bursa and the rotator cuff and to produce symptoms of impingement. Our modified acromioplasty is done in two steps: the portion of the acromion that projects anteriorly beyond the anterior border of the clavicle is resected vertically and then an anteroinferior acromioplasty is performed. We studied the results in patients who had been operated on by the senior one of us and who had been followed clinically for a minimum of two years. At the most recent follow-up visit, no difference in terms of pain and function was found between the patients who had had the modified acromioplasty only (Group I) and the patients who had had the modified acromioplasty and repair of the rotator cuff (Group II); thirty-three (89 per cent) of the patients in Group I and thirty (88 per cent) of those in Group II had a good or excellent result.

Acromion↗
PubMed2002

Cooperation of Hoxa5 and Pax1 genes during formation of the pectoral girdle.

Hox and Pax transcription factors are master regulators of skeletal and organ morphogenesis. Some skeletal malformations encountered in Hoxa5 mutants are shared by the undulated (un) mice, which bear a point mutation in the Pax1 gene. To investigate whether Hoxa5 and Pax1 act in common pathways during skeletal development, we analyzed Hoxa5;un compound mutants. Our genetic studies show that Hoxa5 and Pax1 cooperate in the vertebral patterning of the cervicothoracic transition region and in acromion morphogenesis. The dynamics of expression of Hoxa5 and Pax1 in the pectoral girdle region suggest that both genes function in a complementary fashion during acromion formation. Whereas Pax1 is required for the recruitment of acromion precursor cells, Hoxa5 may provide regional cues essential for the correct formation of the acromion by ensuring Pax1 expression at the proper time and position during morphogenesis of the pectoral girdle. Hoxa5 also has a distinctive role in specifying the fate of perichondrial and chondrogenic cell lineages in a Sox9-dependent way.

Animals↗
PubMed1993

The influence of variations of the coracoacromial arch on the development of rotator cuff tears.

In order to define the geometry of the coracoacromial arch in both its bony and soft parts and to bring it into relationship with rotator cuff tears, 54 cadaver shoulders (from subjects aged 47-90 years) were dissected and X-rayed (anteroposterior projection and supraspinatus outlet view). Partial rotator cuff tears were assessed additionally by transillumination and polarized microscopy. After transfixation of the coracoacromial arch with a polyurethane mould, sections were made along the coracoacromial ligament. The morphology of the acromion was described following the classification of Bigliani et al. [5]. Amongst other parameters, measurements were taken between the long axis of the scapula, the spina, and the acromion. In 19 of 22 cases, a traction osteophyte was associated with rotator cuff tears. In incomplete tears, spurs were completely encased within the ligament and did not impair the subacromial space. The number of rotator cuff tears was significantly increased in shoulders with "curved" acromia, flat acromial slope, and increased angle between the scapular plane and the spina (intact, mean 58 degrees; tears, mean 47 degrees). The morphology of the subacromial space was secondarily determined by this angle. In contrast to Bigliani et al. we were unable to find a "hooked" acromion. These results indicate that the combination of a flat and curved acromion or a position of the acromioclavicular joint above the cranial pole of the glenoid must be regarded as considerable risks for the development of rotator cuff tears. The concept of anterior acromioplasty is supported by our results.

Acromioclavicular Joint↗
PubMed2006

Deviation of skin marker from bone target during movement of the scapula.

BACKGROUND: Recording movement of the scapula by non-invasive techniques is fraught with technical difficulty. One convenient method involves placing a single marker on the skin overlying the acromion. The purpose of this study was to compare translatory discrepancies between marker and underlying bone for seven markers affixed to the skin overlying different parts of the scapula. METHODS: The markers were small plastic spheres filled with machine oil, clearly visible on magnetic resonance imaging (MRI), placed over seven loci of the scapula, including the acromion, spine, medial border, lateral border, and inferior angle. Nine healthy men participated, assuming three positions in the MRI apparatus: (1) arm at the side of the trunk (starting position); (2) arm in full elevation over the head; and (3) hand placed behind the back at the thoracolumbar area. Visible markers and three loci of the scapula itself were digitized on each MRI scan, enabling calculation of changes in location of each marker relative to the scapula between the starting position and either of the other two positions. RESULTS: Among the seven loci examined, the marker placed atop the acromion deviated least from its target, 39 +/- 1 mm (mean +/- standard deviation) for full elevation and 15 +/- 1 mm for moving the hand behind the back. Markers along the medial border and at the inferior angle exhibited relatively large deviations, on the order of 8 mm for full elevation and 3 mm for moving the hand behind the back. CONCLUSIONS: For the two movements studied, involving full range of motion in the shoulder complex, translation of the scapula is most accurately recorded if the marker is placed over the acromion, but the systematic error is too large for such tracking to be deemed precise.

Acromioclavicular Joint↗
PubMed2004

Repeated hemarthrosis with massive rotator cuff tear.

An 80-year-old woman with repeated hemarthrosis of the right shoulder was examined and treated arthroscopically. Plain radiographs indicated narrowing of the acromiohumeral interval (3 mm) with large acromial spur. Under fluoroscopic visualization, the impingement between the humeral head and the medial edge of the acromion was seen at 50 degrees abduction. The area of impingement of the humeral head seemed to be just medial to the greater tuberosity. Arthroscopically, a crater formation was seen at this site. Active bleeding was seen at the center of the crater, which was interpreted as the principal cause of intra-articular hemorrhaging. The undersurface of the acromion was irregular because of the presence of osteophyte. At 50 degrees abduction, the crater impinged with the medial edge of the acromion. We assume that both the presence of osteophyte and the instability caused by the massive rotator cuff tear might contribute to the attrition of the humeral head. In this patient, intra-articular hemorrhaging was successfully treated arthroscopically by coagulation of the bleeding point with minimal abrasion of the undersurface of the acromion. We believe that the arthroscopy facilitated the clinical management of the repeated hemarthrosis with massive rotator cuff tear.

Aged↗
PubMedDate not supplied

Useful boundaries of the subacromial bursa.

The anatomic boundaries the subacromial bursa may serve as a useful guide for surgical orientation and safety. The goals of this study were to measure the minimum distance between the subdeltoid reflection of the subacromial bursa and the circumflex branch of the axillary nerve and to identify relationships between the margins of the subacromial bursa and the acromion, rotator cuff, and acromioclavicular joint. Seventeen fresh-frozen cadavers (mean age, 69 years), were included. Eleven cadavera were dissected only after the subacromial bursa was injected with a latex solution to define the peripheral boundaries of the bursa. The bursal margins were always 2 cm or more from the anterolateral corner of the bursal acromial surface and the bursa lined the anterior half of the anteroposterior distance of the acromion. The mean distances from all points of the acromion to the axillary nerve averaged approximately 5 cm. The mean minimum distance from the subdeltoid bursal reflection to the axillary nerve was 0.8 +/- 0.5 cm with a range of 0.0 to 1.4 cm. In the unelevated extremity, the inferior bursal reflection was always cephalad to the axillary nerve even when the two structures were apposed. Surgeons should exercise caution when approaching the inferior boundary of the subdeltoid bursal reflection because of the proximity to the axillary nerve. We recommend coupling previously reported "safe deltoid-split" distances to this useful anatomic landmark to prevent nerve injury. Furthermore, the central location of the anterolateral corner of the acromion within the bursal space can be applied to needle placement for injection, arthroscopic diagnosis or treatment and mini-open rotator cuff repairs.

Acromioclavicular Joint↗
PubMed1997

[Impingement syndrome of the subacromial area: analysis of 42 cases].

To create a new classification of subacromial impingement phenomena according to different etiology, we treated 42 cases of impingement syndrome. They were 29 male, and 23 females, with an average age of 45 years. 29 patients had typical subacromial pain are signs. Positive impingement test was found in 30 patients. Roentgenographic findings showed that the high density of the great tuberosity (GT) in 27 cases, 8 cases got the cystic changes around the CT, and exostosis formed on the G. T. in 3 cases. The abnormal acromion with sloped or over hanging form was found in 6 cases. 11 cases had an irregular inferior surface of the acromion in two cases with the spur formed at inferior surface of acromion. Four patients combined with calcium deposit at subacromial space. Space narrowing of the AH interval was in noted 12 cases. According to the X-ray findings, 35 cases were classified into the abnormal anatomy structure group. The other 7 patients were in dynamic impingement group. 13 cases of impingement syndrome combined with the complication of rotator cuff tear were treated by the Mclaughlin's procedure for repairing the rotator cuff with the acromion plasty. 11 patients were followed up for more than 6 months after operation. 7 cases had excellent results and 4 cases good results. This classification includes two kinds of impingement syndromes: anatomical of structural and dynamic or dysfunction.

Adult↗
PubMedDate not supplied

Selective block of the brachialis motor point. An anatomic investigation of musculocutaneous nerve branching.

BACKGROUND AND OBJECTIVES: Injections of neurolytic agents designed to block the musculocutaneous nerve often eliminate all elbow flexion movements, leaving the patient with a flail arm. In such patients, motor point blocks of the biceps brachii or brachialis muscle, or both, may be indicated. By virtue of its relative cross-section area, the brachialis is the largest contributor to elbow flexion. This factor, together with this muscle's lack of a role in supination, makes it the target of choice for controlling flexion spasticity. There are few descriptions of brachialis motor point blocks, and they fail to provide satisfactory instructions for the procedure. The goal of this study was to determine the brachialis motor point site and to quantitatively describe its location. METHODS: In this prospective, randomized study of 26 cadaver arms, the innervation site of the brachialis muscle from the musculocutaneous nerve was measured. Measurements were taken from the lateral epicondyle and were compared with the distance to the biceps motor point. These lengths were normalized across subjects by dividing by the arm length (from lateral epicondyle to the acromion). RESULTS: The brachialis was found to be innervated at approximately one third of the distance from the elbow to the acromion. This site is significantly different (P < .05) from that of the biceps brachii, which was found to be located at approximately half of the distance from the elbow to the acromion. CONCLUSIONS: An injection one third of the distance from the lateral epicondyle to the acromion along the medial aspect is recommended to provide best access to the brachialis motor point. By injecting from the medial aspect, one avoids the humerus (encountered in a lateral approach) and the need to pass through the biceps brachii (as in an anterior approach).

Arm↗
PubMed1993

Degenerative change and rotator cuff tears. An anatomical study in 160 shoulders of 80 cadavers.

In order to determine the effects of friction and rubbing in the development of rotator cuff tear, we studied 160 shoulders of 80 cadavers (age at death 43-93 years, mean 69.3 years). Seventy-two cadavers were fixed with formalin and eight were fresh cadavers. The surface of the cuff and the undersurface of the acromion were observed macroscopically. Eight shoulders of fresh cadavers were examined by scanning electron microscopy. Ninety-eight specimens (61%) showed degenerative changes of the supraspinatus tendon. The number of tendons with degeneration and tear increased from the fifth to sixth decade of life, and the size of the tear increased with age. However, there was no sustained increase in the incidence with aging from the age of 60 to 90 years, and the percentage with degenerative changes of the cuff remained at approximately 60% in each decade. Ninety-six specimens (60%) showed degeneration of the subacromial surface. The percentage with degeneration of the undersurface of the acromion remained at approximately 60% from the sixth to ninth decade. There was a significant correlation between the severity of the changes in the rotator cuff and the subacromial surface. Scanning electron microscopy showed changes suggesting effects of friction and rubbing on the rotator cuff, such as regularly arranged wool-like spherical structures on the surface of the tendon and rounded ruptured ends of the tendon fibers. These results indicate that degenerative change of the rotator cuff is aggravated by a friction and rubbing mechanism with the undersurface of the acromion and leads to development of a complete tear.

Acromion↗
PubMed2000

Anatomical basics, variations, and degenerative changes of the shoulder joint and shoulder girdle.

This paper summarizes the anatomical basics of the shoulder, their variations, and precise definitions, including differential diagnoses. It also describes the characteristic degenerative changes caused by aging. A typical variation (7-15%) is the os acromiale, which forms the triangular epiphysis of the scapular spine. This abnormality must be differentiated from a fracture of the acromion or a pseudarthrosis. Because ossification of the acromion is complete after age 25, the os acromiale should be diagnosed only after this age. The shape of the acromion is a further important feature. In a recent anatomical study, the following frequencies of the Bigliani-types of the acromial shape were anatomically determined - type 1 (flat), 10.2% and type 2 (curved), 89.8%. Type 3 (hooked) was not observed, which indicates that this type is probably a misinterpretation of the so-called acromial spur. Minor dehiscences and perforations in the infraspinate or supraspinate fossa should not be confused with malignant osteolyses. The scapula has three ligaments of its own, (1) the coracoacromial ligament and its osseous fixations form an osteofibrous arch above the shoulder joint, which plays a part in impingement syndrome; (2) the superior transverse scapular ligament or its ossified correlate arches the scapular incisure and can cause a typical compression syndrome of the suprascapular nerve; (3) the inferior transverse scapular ligament is of no great clinical importance. Two intraarticular structures (glenoid labrum and tendon of the long bicipital head) must be mentioned. The glenoid labrum consists of dense connective tissue and surrounds the margin of the glenoid cavity. Two areas exhibit specialized conditions, cranial at the supraglenoid tubercle an intimate relationship exists to the tendon of the long bicipital head and in about 55% of cases, the labrum is stretched over the glenoid rim at the ventral side. At the area of the biceps-tendon-labrum complex, so-called SLAP-lesions may occur and at the glenoid rim, where the labrum is often not fixed to the bony margin, avulsions of the labrum may occur. This well-established anatomical condition must not be mistaken for a manifest Bankart-lesion. The glenohumeral ligaments, which are located in the ventral articular capsule, have a stabilizing function for the ventral part of the glenoid labrum. The glenohumeral ligaments lift the articular lip where it crosses the glenoid notch. This 'labrum-lift effect' supports the stabilizing features of the articular lip and the glenohumeral ligaments. The rotator cuff is composed of the tendons of the teres minor, infraspinatus, supraspinatus, and subscapularis muscles. This cuff has a poorly vascularized area, due to mechanical conditions, about 1.5 cm from the major tubercle, which causes degenerative changes and eventually may lead to ruptures. Results of the impingement-syndrome and the osteoarthrotic changes of the shoulder and acromioclavicular joint are also presented and discussed. Finally, the coracoclavicular joint, which probably represents no congenital entity but appears due to a changed, lowered position of the shoulder girdle, is discussed. The paper also presents instructive figures of anatomical preparations that can be used to make more precise radiological and differential diagnoses. All preparations were done by the author and are part of a series of more than 300 preparations of the shoulder joint and girdle.

Acromion↗
PubMedDate not supplied

Successful osteosynthesis of an unstable mesoacromion in 6 shoulders: a new technique.

Six patients with impingement syndrome associated with an unstable mesoacromion underwent successful acromial fusion performed with a new technique. Preoperative symptoms included pain from a combination of 3 sources: movement at the mesoacromial cleft, junction of the medial cleft with the distal clavicle, and dynamic impingement of the unstable anterior acromion on the underlying rotator cuff. Two patients reported the onset of pain after a blow to the top of the acromion that supposedly rendered the mesoacromion unstable. Three patients had a tear of the supraspinatus tendon. The operative technique utilized 4.5-mm cannulated Herbert screws for fixation, a dorsal wedge osteotomy of the nonunion site, a dorsal bone graft fashioned from an anterior acromion cut, a figure-of-eight suture, and a postoperative abduction brace. Tilting the anterior acromial fragment up and fusing it together worked to relieve impingement. An acromioplasty was not performed. The 3 rotator cuff tears were repaired. After 3 to 6 years of follow-up, all 6 shoulders were rated as excellent according to criteria similar to that of the American Shoulder and Elbow Surgeons.

Acromion↗
PubMed2002

Trajectories of target reaching arm movements in individuals with spinal cord injury: effect of external trunk support.

DESIGN: Deficits in trunk control due to spinal cord injury (SCI) lead to slower target-reaching movements of the hand. We investigated whether the movement path is also affected, and whether providing external support for the trunk can abolish the kinematic differences. OBJECTIVE: To compare movement trajectories between individuals with SCI and neurologically normal individuals, with and without external trunk support. SETTING: Neural Control/Biomechanics Laboratory, University of Illinois, Chicago, USA. METHODS: Five subjects with levels of injury between C7 and T4 were tested 3-8 years post-injury, and compared with five control subjects. Two targets were employed. Trajectories were recorded by a motion-capture system using infrared emitting markers. Peak speed and path curvature were calculated for the fingertip and for the acromion. RESULTS: Compared with control subjects, the subjects with SCI exhibited lower peak speed of the fingertip but not of the acromion, and less straight paths for both. When the trunk was supported externally, the difference in fingertip speed persisted. The support abolished the difference in path curvature for the fingertip but accentuated that for the acromion. CONCLUSION: The slower hand movements of individuals with SCI are not simply time-scaled versions of those of normal subjects, and the provision of trunk support does not erase the kinematic differences between the reaching movements of the two groups.

Acromion↗
PubMedDate not supplied

[The architecture of the subacromial space after full thickness supraspinatus tears].

AIM: The etiology of rotator cuff tears is multifactorial. An important factor is the damage of the rotator cuff by narrowing of the subacromial space. The purpose of this investigation was to estimate the influence of various metrical parameters on the size of the subacromial space. METHOD: We investigated 161 human macerated scapulae, 36 of them had a known tear of the supraspinatus tendon. All scapulae were photographed in two standard positions from the front and the lateral side. Defined distances and angles were measured using an image analyzing system followed by statistical analysis. RESULTS: Shoulders with a tear of the supraspinatus tendon showed a trend towards higher incidences of hooked acromions. Furthermore we found a significant higher incidence of elongated oval shaped glenoids in the group with supraspinatus tendon tear. In comparison to normal shoulders a significantly smaller distance from the top of the glenoid to the tip of the acromion and a greater distance from the top of the glenoid to the tip of the coracoid process was measured. In addition there was a significantly smaller coracoid angle and a smaller glenoid-spinal angle in this group. CONCLUSION: The width of the subacromial space depends on various parameters. Our data suggest that besides the acromion type the shape of the coracoid, the acromial angle, the spine-scapula angle and the cavitas-spine angle should be taken into account for diagnostic and therapeutic decisions.

Acromion↗
PubMedDate not supplied

The fate of the coracoacromial ligament in arthroscopic acromioplasty: an anatomical study.

This study defines the normal anatomical relationships among the coracoacromial ligament, the deltoid, and the acromion in cadavers. The effect of arthroscopic acromioplasty on the acromial attachments of the coracoacromial ligament and the anterior fibers of the deltoid was also studied. After arthroscopic acromioplasty, the fibers of coracoacromial ligament and overlying deltoid inserting into the anterior part of the acromion remained attached to the acromion by a bridge of tissue composed of periosteum and collagen fibers of the coracoacromial ligament and deltoid tendon. We have called this the coracoacromial-deltoid-periosteal complex; it has not previously been described. This study demonstrates that arthroscopic acromioplasty preserves the acromial attachment of the coracoacromial ligament and the anterior fibers of the deltoid.

Acromion↗
PubMedDate not supplied

Surgical management of the symptomatic os acromiale.

Os acromiale is an uncommon cause of shoulder pain with symptoms often resulting from an unstable meso-acromion. The associated pain may be due to impingement from the unfused fragment, a concomitant rotator cuff tear, or gross motion at the os acromiale site. Currently, initial treatment includes physical therapy, nonsteroidal anti-inflammatory agents, and subacromial corticosteroid injections. Surgical intervention is reserved for patients who do not respond to nonoperative treatment. Treatment options include open fragment excision, open reduction and internal fixation, and arthroscopic decompression. Open fragment excision can lead to persistent deltoid dysfunction and should be reserved for small fragments or after failed internal fixation. Open reduction and internal fixation allows for both preservation of large fragments and anterior deltoid function. Internal fixation is technically difficult, has led to frequent nonunion rates and often requires hardware removal as a result of postoperative irritation. Arthroscopic subacromial decompression with complete or nearly complete resection of the unstable meso-acromion can be performed without the aforementioned complications. The surgical technique requires no special instrumentation and may be performed reproducibly by those familiar with arthroscopic techniques of the shoulder. Advantages include more rapid rehabilitation, better range of motion, and shorter surgical times. Satisfactory short-term results have shown this to be an effective treatment option for the unstable meso-acromion.

Acromion↗
PubMed2001

Osseous anatomy of the scapula.

Detailed anatomy and morphometry of the scapula were obtained to provide information for surgical procedures such as hardware fixation, drill hole placement, arthroscopic portal placement, and prosthetic positioning. Twenty-six measurements were made in 15 pairs of scapulas from cadavers. The average length of the scapulas from the superior to the inferior angle was 155 +/- 16 mm (mean +/- standard deviation). The thickness of the medial border 1 cm from the edge was 4 +/- 1 mm. The superior border was sharp and thin, and the suprascapular notch was present as a foramen in two scapulas. The distance from the base of the suprascapular notch to the superior rim of the glenoid was 32 +/- 3 mm. The length of the spine from the medial edge of the scapula to the lateral edge of the acromion was 134 +/- 12 mm. The anteroposterior width of the spine at 1 and 4 cm from the medial edge was 7 +/- 1 and 18 +/- 3 mm, respectively; the width at the lateral edge (spinoglenoid notch) was 46 +/- 6 mm. The acromion measured 48 +/- 5 mm x 22 +/- 4 mm and was 9 +/- 1 mm thick. The acromial shape was flat in 23%, curved in 63%, and hooked in 14% of scapulas. The distance from the glenoid to the acromion was 16 +/- 2 mm. The glenoid dimensions were 29 +/- 3 mm (anteroposterior) x 36 +/- 4 mm (superoinferior) and faced posterior by 8 +/- 4 degrees. Anteroposterior thickness of the head of the scapula 1 cm from the surface was 22 +/- 4 mm. The thickness of the coracoid was 11 +/- 1 mm. The average length of the coracoacromial ligament was 27 +/- 5 mm. Scapulas from male cadavers were significantly larger than scapulas from female cadavers in 19 measurements.

Acromion↗
PubMedDate not supplied

Open reduction internal fixation after displacement of a previously nondisplaced acromial fracture in a multiply injured patient: case report and review of literature.

SUMMARY: A twenty-eight-year-old multiple trauma patient had a nondisplaced acromion fracture that was not detected until after it had displaced. Open reduction internal fixation was performed without complication and the patient achieved excellent shoulder abduction strength. Nondisplaced acromion fractures may displace if not protected. Open reduction internal fixation of displaced acromion fractures should be considered if deltoid muscle strength is important to the patient.

Acetabulum↗
PubMed2005

Anterior acromioplasty for the chronic impingement syndrome in the shoulder. 1972.

Impingement on the tendinous portion of the rotator cuff by the coracoacromial ligament and the anterior third of the acromion is responsible for a characteristic syndrome of disability of the shoulder. A characteristic proliferative spur and ridge has been noted on the anterior lip and undersurface of the anterior process of the acromion and this area may also show erosion and eburnation. The treatment of the impingement is to remove the anterior edge and undersurface of the anterior part of the acromion with the attached coracoacromial ligament. The impingement may also involve the tendon of the long head of the biceps and if it does, it is best to decompress the tendon and remove any osteophytes which may be in its groove, but to avoid transplanting the biceps tendon if possible. Hypertrophic lipping at the acromio-clavicular joint may impinge on the supraspinatus tendon when the arm is in abduction and, if the lip is prominent, this joint should be resected. These are the principles of anterior acromioplasty.

Acromion↗