Anatomy and histological characteristics of the spinoglenoid ligament

The spinoglenoid (inferior transverse scapular) ligament, when present, is located at the spinoglenoid notch. The ligament originates on the spine of the scapula and inserts on the superior margin of the glenoid neck. Because of discrepancies in the literature, we sought to determine its prevalence and to define its histological characteristics. We dissected 112 shoulders of seventy-six cadavera and classified the ligament as absent or an insubstantial structure, a thin fibrous band (type I), or a distinct ligament (type II). We found no distinct ligamentous structure in twenty-two shoulders (20 percent), a type-I ligament in sixty-eight shoulders (61 percent), and a type-II ligament in twenty-two shoulders (20 percent). Overall, ninety (80 percent) of the shoulders had a fibrous band of tissue that, together with the spine of the scapula, formed a narrow fibro-osseous tunnel through which the suprascapular nerve traveled. The bone-spinoglenoid ligament-bone complexes from three specimens were analyzed histologically. There were two type-I ligaments and one type-II ligament; all three ligaments were composed of collagen fibers. One type-I ligament and the type-II ligament demonstrated Sharpey fibers at their origin on the spine of the scapula. The other type-I ligament attached to the spine of the scapula through the periosteum. All three ligaments inserted into the periosteum of the glenoid neck.     

Immunoglobulin gene organization and the mechanism of repertoire development

Twenty-two cases of suprascapular nerve entrapment caused by supraglenoid cyst compression were reviewed. Pain and weakness were the presenting symptoms in 14 shoulders and pain alone in 8. Twenty of the cysts were diagnosed by magnetic resonance imaging, and two were confirmed at surgical exploration. Electromyography of 20 shoulders was positive for neurologic involvement for both the infraspinatus and supraspinatus in 4 cases, for the infraspinatus only in 12, and negative in 4. Sixteen shoulders were treated by open excision, arthroscopy, or both. Superior labral lesions were diagnosed in 11 of 12 patients who underwent arthroscopy. At follow-up 10 of the patients who underwent surgery had complete resolution of symptoms, 5 had occasional pain or weakness, and 1 recurrence required a second surgery. Of six patients treated without surgery, two improved and four had no change. Supraglenoid ganglion cysts are common and can easily be diagnosed by magnetic resonance imaging. For patients with symptoms arthroscopy with repair of the superior labral lesion and either arthroscopic debridement or direct open decompression and excision of the cyst is recommended.     

Glenoid-labral cyst entrapping the suprascapular nerve: dissolution after arthroscopic debridement of an extended SLAP lesion

Glenoid labral cysts are commonly associated with labral tears, which can cause pain or instability. We present the case of a patient, referred for neurological complaints, who was actually suffering from supraspinatus nerve entrapment syndrome. Electroneurogram studies showed an isolated lesion of the branch to the infraspinatus muscle. Magnetic resonance imaging confirmed a glenoid labral cyst extending from the cranial glenoid to the scapular notch. After arthroscopic debridement of an extended SLAP-lesion that had caused joint fluid extrusion, the dissolution of the cyst was associated with complete neurological recovery. The patient is pain free and range of motion is normal. An attempt at an arthroscopic procedure seems warranted in cases like this, since cysts that accompany labral tears can dissolve after rigorous debridement of the torn labrum, much like meniscal cysts. Extended and hazardous open excisions can thus be avoided.     

Temperature dependence on the recovery of electrical activities in brain slice during incubation

Four cases of suprascapular neuropathy treated by nonoperative means have been presented. Complete recovery occurred in all four. The anatomy of the suprascapular nerve and probable mechanisms of injury secondary to traction have been discussed. The importance of electromyography in diagnosis has been stressed. Longer periods of nonoperative treatment are recommended here than by previous authors. Since the lesion is felt not to be an entrapment phenomenon but, rather, a traction injury, operative treatment should consist of release of the nerve at the notch to reduce the possibility of further traction injury, and a neurolysis should be done as well.     

Study of the olfactory effects of citronellal in the environmental air

The study was performed using four cadavers of adult persons with the method of preparation. The access to the ligament was obtained by the removal of the inferior orbital wall and inferior orbital adiposal layer. Topographical anatomy of Lockwood ligament, its interrelations with inferior rectus and oblique muscles and attachment to lateral and medial orbital walls were studied. Lockwood ligament, the transverse fascial structure that supports the eyeball, stabilizes it, providing the framework for inferior rectus and oblique muscles of the eye.     

Defects in signal transduction during replicative senescence of diploid human fibroblasts in vitro

Decompression of the suprascapular nerve through the posterior approach minimizes muscular damage and postoperative scar. The difficulty with this approach is that the depth of the exposure makes operating around the delicate structures of the suprascapular artery and nerve challenging. Spine surgery instrumentation is very helpful in circumventing this problem. Once exposure is achieved, a nerve root retractor is used to retract the suprascapular artery and vein. A number 2 Woody Woodson elevator is used to protect the suprascapular nerve. A number 1 or 2 Kerrison rongeur is then used to resect the suprascapular ligament. The Kerrison rongeur is a particularly useful instrument if an ossified ligament is encountered.     

Bulk effect of rotator cuff on inferior glenohumeral stability as function of scapular inclination angle: a cadaver study

Eleven fresh cadaver shoulders were studied to determine the static contribution (bulk effect) of the rotator cuff on inferior glenohumeral stability provided by scapular inclination. All musculature, including the rotator cuff, was removed. The position of the humerus relative to the scapula was recorded using an electromagnetic tracking device under conditions of no force and 1.5 kg of inferior translation force applied to the humerus, with the arm in the hanging position (sulcus test) and then in 90 degrees abduction (Abduction-Inferior Stability test = ABIS test), with the scapula inclined referable to the vertical line at -15 degrees, 0 degrees, 15 degrees and 30 degrees in the sulcus test and at 15 degrees, 30 degrees, 45 degrees and 60 degrees in the ABIS test. In the sulcus test without load, all shoulders dislocated at scapular inclination angles of -15 degrees and 0 degrees, whereas no shoulders dislocated at 30 degrees. The angle of scapular inclination had a significant effect on humeral head positions (p < 0.0001), with the head position at -15 degrees and 0 degree being lower than at 15 degrees, which was lower than at 30 degrees. In the ABIS test, none of the shoulders dislocated, although the effect of the angle of scapular inclination was significant (p < 0.0001), with the position of the humeral head being higher at 15 degrees than at other angles of inclination. Comparison of these data and previously reported data with the cuff intact showed no significant effect of rotator cuff removal on humeral head position and displacement in both tests. Therefore, we conclude that the static condition of the rotator cuff has no significant effect on the stabilizing function of scapular inclination. The stabilizing mechanism of scapular inclination seems to be associated with the bony configuration and/or anatomy and biomechanical properties of the superior capsuloligamentous structures.     

An intra-articular fracture-dislocation of the acromioclavicular joint

A hybrid acromioclavicular joint fracture-dislocation in which an intra-articular fracture of the distal clavicle coexisted with a coracoclavicular ligament injury is described. The proposed mechanism of injury is a fall on the point of the shoulder that simultaneously drives the scapula both anteriorly and inferiorly. Forced anterior scapular protraction caused a displaced horizontal plane fracture of the inferior half of the distal clavicle, which was separated from the remainder of the clavicle. The inferiorly acromioclavicular ligament was still attached to this distal clavicle fragment. The inferiorly directed force ruptured the coracoclavicular and superior acromioclavicular ligaments.     

Enhancement of antipsychoticlike properties of raclopride in rats using the selective serotonin2A receptor antagonist MDL 100,907

OBJECTIVE: To study the superior-inferior stabilizing functions of the coracohumeral ligament (CHL) and the rotator interval capsule (RIC) with use of a material testing machine. MATERIAL AND METHODS: The axial translations of the humerus with the superior-inferior translation force of 30 N applied were recorded under the following joint capsule conditions: (1) intact, (2) vented, (3) the CHL sectioned, and (4) the RIC incised in six cadaver shoulders. The order of sectioning was changed for conditions 3 and 4 in six other cadaver shoulders. RESULTS: With the arm in internal and neutral rotations, venting the capsule significantly increased the superior-inferior translation, which was unaffected by further sectioning of the CHL and the RIC. With the arm in external rotation, only the CHL contributed significantly to inferior stability, whereas both this ligament and the RIC contributed to superior stability to a lesser degree. CONCLUSION: The CHL is a stabilizer in superior inferior directions with the arm in external rotation, and the intra-articular pressure that is maintained by the intact RIC is a stabilizer in superior-inferior directions with the arm in internal and neutral rotations. These findings may provide a scientific background to support closure of the interval space to stabilize the shoulder and may explain part of the superior instability observed in shoulders with rotator cuff tears.     

Prevalence of morphological changes in the surfaces of the temporomandibular joint disc associated with internal derangement

PURPOSE: The purpose of this study was to determine the prevalence of morphological changes in the superior and inferior surfaces in the temporomandibular joint (TMJ) disc and relate them to disc displacement. MATERIALS AND METHODS: Thirty TMJs obtained from fresh cadavers were studied. The TMJs were dissected, and the superior and inferior surfaces of the disc were inspected and classified as intact, irregular, or perforated. These findings were corrolated to the position of the disc. RESULTS: There was a greater prevalence of morphologic changes in the inferior (57%) than in the superior surface (17%) of the disc (P < .001). This was found for joints both with normal disc position and those with disc displacement. There was no relationship between surface irregularities of the inferior surface and the position of the disc. Perforation was seen more frequently in joints with disc displacement than in those with normal disc position. CONCLUSION: Morphologic changes in the inferior surface of the TMJ disc are more prevalent than those in the superior surface, but this is not related to disc position. However, this needs to be considered when doing arthroscopy of only the superior joint compartment.     

Suprascapular nerve entrapment in a basketball player

A basketball player was shown to have a suprascapular nerve lesion without any history of shoulder girdle trauma. This acute neuropathy, never previously described in basketball players, is a result of repeated micro-trauma, due to nerve traction over the coracoid notch during violent movement ("dunking" most probably). Clinically, he was unable to abduct his arm and had some difficulty in external rotation. He developed atrophy in both the supra- and the infraspinatus muscles. Nerve conduction latency to the supraspinatus muscle was 8.0 ms, and to the infraspinatus, 8.5 ms. The compound muscle action potential registered in the supraspinatus was 1.224 mV, and in the infraspinatus, 1.237 mV. After 3 weeks of inactivity, recovery was spontaneous and practically complete.     

Functional evaluation of the ligaments at the acromioclavicular joint during anteroposterior and superoinferior translation

We examined the anatomy and measured the in situ force in ligaments at the acromioclavicular joint using a universal force-moment sensor. The in situ force in the coracoacromial, conoid, trapezoid, superior acromioclavicular capsular, and inferior acromioclavicular capsular ligaments of 10 fresh-frozen cadaveric shoulders was determined for a load of 70 N applied to the clavicle in anteroposterior and superoinferior directions. The lengths of the conoid and trapezoid ligaments were found to be 15.1 +/- 4.1 and 11.5 +/- 2.2 mm, respectively; the widths of the conoid and trapezoid ligaments were 10.7 +/- 1.5 and 11.0 +/- 2.8 mm, respectively. The in situ force of the trapezoid (42.9 +/- 15.4 N) was significantly greater than that for the other ligaments during posterior displacement. Otherwise, no statistically significant differences could be found between any of the in situ forces in each ligament during all other motions examined. During anterior displacement, the inferior acromioclavicular capsular ligament appeared to be the major restraint. The trapezoid ligament was the primary restraint during posterior displacement and provided 55.8% +/- 20.0% of the resisting force. Our results suggest that the coracoclavicular and other acromioclavicular joint capsular ligaments should be considered for reconstruction to restore normal joint function, especially in the anterior, posterior, and superior directions.     

Superior glenoid impingement. Current concepts

In the current decade impingement syndrome is becoming a less precise diagnostic entity. It is splitting into several categories of more exact diagnoses. The concept development, clinical picture, and currently recommended treatment of 1 of these entities, the superior glenoid impingement is reviewed. The complaint may be acute or chronic and may involve 1 or more of 5 structures: (1) superior labrum, (2) rotator cuff tendon, (3) inferior glenohumeral ligament, (4) greater tuberosity, and (5) the bony glenoid. The most commonly seen clinical entity is chronic dorsal shoulder pain in an athlete who throws with a positive relocation test. Treatment consists of strengthening of the cuff and scapular rotators. When there has been excessive inferior ligament stretch this must be augmented by anterior reconstruction.     

Distribution of enteric nerve cells projecting to the superior and inferior mesenteric ganglia of the guinea-pig

Retrograde tracing, using Fast Blue dye, was employed to determine the distribution of enteric nerve cells that project to the superior mesenteric and inferior mesenteric ganglia of the guinea-pig. Retrogradely labelled neurons were found in the myenteric but not submucous ganglia. When the superior mesenteric ganglion was injected, labelled neurons were found in low frequencies (less than 5 nerve cell bodies/cm2) in the duodenum, jejunum, ileum, caecum and proximal colon. The distal colon was analysed in five segments of equal length (1-5; oral to anal). Segment 1 had about 4 labelled nerve cells/cm2, whereas segments 2 to 5 displayed an average of about 25 nerve cells/cm2. The rectum contained about 36 labelled neurons/cm2. After injection of the inferior mesenteric ganglia with Fast Blue, no labelled neurons were found in the duodenum, jejunum, ileum or caecum. No labelled cells were observed in the gallbladder. A small number of labelled cells occurred in the proximal colon and in segment 1 of the distal colon. The frequency of labelled cells increased markedly in the more anal regions of the distal colon, and reached a peak in the rectum (138 cells/cm2). Both nerve lesions and immersion of the cut nerve in Fast Blue solution showed that the superior mesenteric nerve carries the axons of neurons located in the middle distal colon to the superior mesenteric ganglion. Almost half of the neurons in the rectum that project to the inferior mesenteric ganglia do so via the hypogastric nerves.(ABSTRACT TRUNCATED AT 250 WORDS)     

Synovial cyst of the cruciate ligament. Findings with magnetic resonance in 8 symptomatic cases

Intraarticular ganglion cysts are uncommon findings: only 30 cases have been reported since the first paper by Caan in 1924 and they were all associated with cruciate ligaments. Many different cystic or pseudocystic lesions are found in articular knee conditions: the most common cystic lesions are popliteal cysts (Baker's cysts), followed by synovial pseudocysts of the posterior cruciate ligament, meniscal cysts and, finally, ganglion cysts of the cruciate ligaments. In our series of 1600 knee MR exams carried out in our MR department since June, 1994, we have found 8 ganglion cysts of the cruciate ligaments. MR studies are always performed on a dedicated 0.2-T permanent magnet (Artoscan, Esaote Biomedica, Genoa, Italy). Five patients were operated on with arthroscopy. The ganglion cysts affected the anterior cruciate ligaments in 4 cases and the posterior cruciate ligaments in 4 cases. The symptoms were mainly pain radiating to the medial side and worsening in forced flexion or extension. The diagnostic suspicion was meniscal tears in 4 patients, chondral lesions in 3 and a loose intraarticular body in one patient. The shape and structure of ganglion cysts in the cruciate ligaments are clearly depicted with MRI. The ganglion cysts in the anterior cruciate ligaments are usually spindle-shaped and within the ligament, while those in the posterior cruciate ligaments have a well-defined outline, with multilocular appearance, and they are usually localized along the ligament, most often on the dorsal aspect. MR signal studies show intermediate signal intensity on SE T1-weighted images and markedly increased signal intensity on SE T2-weighted images. These typical patterns may change depending on lesion content, for instance in the presence of hemoglobin due to an associated angioma. The origin of ganglion cysts in the cruciate ligaments is still unknown, even though many theories have been suggested, including a synovial herniation in ligament fibers, the ectopic inclusion of synovial tissue, a posttraumatic connectival degeneration and, finally, the proliferation of totipotent mesenchymal cells. From a histologic point of view, "synovial ganglion" is a much better definition than "synovial ganglion cyst", because the typical wall of real synovial cysts is missing. The MR patterns are typical of the morphological features described and of the presence of high protein fluid content.     

Relationship of the long thoracic nerve to the scapular tip: an aid to prevention of proximal nerve injury

OBJECTIVE: The objective was to determine the course of the long thoracic nerve relative to the scapula as an aid to the prevention of proximal long thoracic nerve injuries. METHODS: Eighteen fresh cadavers (7 male, 11 female) were studied. Each was sequentially placed in the transaxillary and posterolateral thoracotomy positions, and the distance of the long thoracic nerve from the scapular tip and anterior scapular border was measured. The measurements were made bilaterally; the mean, standard deviation, and 99% confidence interval were calculated for each position by gender. RESULTS: Distances from the scapular tip to the long thoracic nerve are listed as mean/outer range: transaxillary thoracotomy, male 4.9/7.0 cm left, 5.2/7.5 cm right; female 4.3/5.0 cm left, 4.7/6.0 cm right; posterolateral thoracotomy, male 3.1/6.0 cm left, 4.5/5.1 cm right; female 3.2/4.5 cm left, 3.8/5.5 cm right. In all instances, the long thoracic nerve was furthest from the scapula at its tip. CONCLUSION: For patients positioned for a transaxillary thoracotomy, incision sites should be at least 7.5 and 6.0 cm anterior to the scapular tip for male and female patients, respectively. For patients in posterolateral thoracotomy positioning, incisions should be 6.0 and 5.5 cm anterior to the scapular tip for male and female patients, respectively. By using these anatomic guidelines, we believe that the incidence of iatrogenic proximal long thoracic nerve injury can be minimized.     

Correlation between ossification of the stylohyoid ligament and osteophytes of the cervical spine

OBJECTIVE: To investigate the correlation between ligamentous ossification or osteophytes of the cervical spine and ossification of the styloid process and stylohyoid ligament, and to determine any relation between diffuse idiopathic skeletal hyperostosis (DISH) of the thoracic spine and ossification of the styloid process and stylohyoid ligament. METHODS: Four patients having cervical spine DISH, an elongated styloid process and/or variable patterns of stylohyoid ligament ossification, and clinical findings compatible with Eagle's syndrome are described. Cervical computed tomography scans of 100 patients who also had lateral radiographs of the thoracic spine were reviewed. Point biserial and Spearman rank correlation analysis, McNemar test, chi-squared test, and Fisher's exact test were used to determine correlation between elongation of the styloid process and/or ossification of the stylohyoid ligament and (1) ligamentous ossification or osteophytes of the cervical spine (the characteristic spinal manifestation of DISH), and/or (2) DISH of the thoracic spine. RESULTS: (1) Elongation of the styloid process and variable patterns of ossification of the proximal, middle, and distal parts of the stylohyoid ligament, and (2) enlargement of this ligament were significantly correlated with transverse and anteroposterior dimensions of ligamentous ossification or osteophytes of the cervical spine at various levels. The prevalence of such abnormalities of this process and ligament was not significantly different between the patients with and without thoracic spine DISH. CONCLUSION: Variable types of styloid process-stylohyoid ligament complex abnormalities have significant correlation with ligamentous ossification and osteophytes of the cervical spine.     

A case of bilateral ulnar nerve palsy in a patient with traumatic brain injury and heterotopic ossification

Heterotopic ossification after head injury may occur in the elbow joint. Rarely does this lead to entrapment of the ulnar nerve. We describe the case of a 20-year-old patient who developed heterotopic ossification 6 weeks after a traumatic brain injury. She subsequently developed bilateral ulnar nerve palsy which was confirmed by electrodiagnostic studies and treated by transposition of the ulnar nerve.     

Involvement of delta- and mu-opioid receptors in the potentiation of brain-stimulation reward

Human, dog, cat and rat dental pulps were investigated for the presence and distribution of galanin-like immunoreactive (-IR) nerve fibers, and the possible origin of pulpal galanin-IR nerve fibers in the rat was examined. Galanin-IR nerve fibers were present in the dental pulps of all species examined. Two types of galanin-IR nerve fibers were distinguished with regard to morphology; thin varicose nerve fibers and thick smooth-surfaced nerve fibers. Thin varicose galanin-IR nerve fibers were seen to run along the blood vessel in the human, dog and cat root pulp. In the coronal pulp, galanin-IR nerve fibers ran toward the odontoblastic layer but they did not form the subodontoblastic nerve plexus. In rat molar pulp, few galanin-IR nerve fibers were observed; the distribution of these nerve fibers was similar to those in human, dog and cat pulp. In contrast, many thick smooth-surfaced galanin-IR nerve fibers were observed near the blood vessels in incisor pulp of the rat; occasionally a few varicose galanin-IR nerve fibers were also observed. Transection of the inferior alveolar nerve or mandibular nerve caused complete disappearance of galanin-IR nerve fibers in rat dental pulp, while surgical sympathectomy of the superior cervical ganglion did not affect their distribution. The present results indicate that galanin-IR nerve fibers are present in the mammalian dental pulp, and that the intrapulpal galanin-IR nerve fibers in the rat originate from the trigeminal ganglion and are primary afferents.