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.

Vascularity of the carpus.

Relatively few studies investigating the vascular patterns of the carpus have been performed. Technical difficulties in identifying small vessels in three dimensions and in determining their location within the thick ligaments about the wrist have led to conflicting anatomic reports. Studies on cadavers in which improved techniques with arterial injection, chemical debridement, and decalcification were used allowed the arterial anatomy of the carpus to be delineated more accurately. The current authors review these arterial patterns, with attention given to the extraosseous and intraosseous vascularities.

Arterial patterns of the deep and superficial palmar arches.

The vascular patterns of the palmar arches and their interconnecting branches present a complex and challenging area of study. Improvements in microsurgical techniques have made a better understanding of vascular patterns and vessel diameters more important. Forty-five fresh limbs from cadavers were amputated at the level of the midhumerus. Ward's red latex or Batson's compound was injected under pressure to visualize the arterial system in the hand. After hardening of the injected material, the skin, subcutaneous tissues, and tendons were removed. The specimens were digested in concentrated potassium or sodium hydroxide leaving the bony elements and a cast of the arterial system. The superficial palmar arch is most easily classified into two categories: complete or incomplete. An arch is considered to be complete if an anastomosis is found between the vessels constituting it. An incomplete arch has an absence of a communication or anastomosis between the vessels constituting the arch. Complete superficial palmar arches were seen in 84.4% of specimens. In the most common type, the superficial arch was formed by anastomosis between the superficial volar branch of the radial artery and the ulnar artery. This was seen in 35.5% of specimens. In 31.1%, the arch was formed entirely of the ulnar artery. Incomplete superficial arches were seen in 15.5% of specimens. In 11.1%, the ulnar artery forms the superficial arch but does not contribute to the blood supply to the thumb and index finger. The deep palmar arch was found to be less variable with 44.4% formed by an anastomosis between the deep volar branch of the radial artery and the inferior deep branch of the ulnar artery. Injection followed by chemical debridement allows direct visualization and measurement of the arches and the smaller arterial branches that are visualized poorly with other techniques. Based on the vessel measured, vessels of the superficial and deep arches are of sufficient size to allow microvascular repair, although repair of the communicating branches, the dorsal carpal rete, and its branches, probably is not feasible because of their small size.

Anatomy and functional significance of the long extensors to the fingers and thumb.

Intrinsic and extrinsic hand muscles power finger extension. These two muscle groups have different anatomy that allows complimentary function at the interphalangeal joints and opposing function at the metacarpophalangeal joints. Independent extension of each finger is not possible because of anatomic constraints including the juncturae tendinum and intertendinous fascia between the extrinsic extensor tendons on the dorsum of the hand. Anatomic variations of the extrinsic extensor tendons are frequent and knowledge is important when assessing the traumatized or diseased hand.

The dorsal aponeurosis, intrinsic, hypothenar, and thenar musculature of the hand.

The intrinsic muscles of the hand consist of seven interossei and four lumbrical muscles. With the extrinsic long extensors, the intrinsic muscles act via the dorsal aponeurosis to control finger motion. The interossei also control finger abduction and adduction, and flexion of the metacarpophalangeal joints. The lumbricals are the main extensors of the interphalangeal joints. The complex structure of the dorsal aponeurosis allows coordination and individual joint motion. The muscles of the hypothenar and thenar eminences also insert into the dorsal aponeurosis and the skeleton of the small finger and thumb, respectively, and are responsible for the specialized motion. Knowledge of the anatomy is necessary for understanding the function in treating abnormalities and trauma to the intricate structures of the hand.

What happens to the triangular fibrocartilage complex during pronation and supination of the forearm? Analysis of its morphology and diagnostic assessment with MR arthrography.

OBJECTIVE: To evaluate the dynamic morphologic changes of the triangular fibrocartilage complex (TFCC) during pronation and supination of the forearm using high-resolution MR arthrography in cadavers and to evaluate the impact of these changes on the diagnostic assessment of the normal and abnormal TFCC. DESIGN AND SPECIMENS: High-resolution MR arthrography of 10 wrists of cadaveric specimens was obtained in maximum pronation, in the neutral position, and in maximum supination of the forearm. The structures of the TFCC were evaluated by two musculoskeletal radiologists and correlated with anatomic sections. The position of the forearm that allowed the best visualization of normal structures and lesions of the TFCC was determined. RESULTS: The shape and extent of the articular disc as well as the radial portions of the radioulnar ligaments did not change with pronation and supination. The articular disc was horizontal in the neutral position and tilted more distally to align with the proximal carpal row in pronation and supination. The fibers of the ulnar part of the radioulnar ligaments (ulnar attachment of the articular disc) revealed the most significant changes: their orientation was coronal in the neutral position and sagittal in positions of pronation and supination. The ulnomeniscal homologue was largest in the neutral position and was reduced in size during pronation and supination. The extensor carpi ulnaris tendon was centered in its groove in the neutral position and pronation. In supination this tendon revealed subluxation from this groove. The dorsal capsule of the distal radioulnar joint was taut in pronation, and the palmar capsule was taut in supination. The preferred forearm position for analysis of most of the structures of the TFCC was the neutral position, followed by the pronated position. The neutral position was rated best for the detection of ulnar and radial detachments of the TFCC, followed by the pronated position, except for two central perforations of the TFCC which were best seen with supination. CONCLUSION: The articular disc and the surrounding radial portions of the radioulnar ligaments form a rigid, unified complex with the radius without change in their shape in positions of pronation and supination of the forearm, while the ulnar attachment of the TFCC shows important dynamic changes. The neutral forearm position is the best position to analyze both the normal and the abnormal TFCC.

Bursal sporotrichosis: case report and review.

We describe a patient whose prepatellar bursa was infected with Sporothrix schenckii. The infection persisted despite itraconazole therapy and cure was achieved only after surgical excision of the bursa. A review of treatments for bursal sporotrichosis is presented.

Pulley system in the fingers: normal anatomy and simulated lesions in cadavers at MR imaging, CT, and US with and without contrast material distention of the tendon sheath.

PURPOSE: To describe the normal anatomy of the finger flexor tendon pulley system, with anatomic correlation, and to define criteria to diagnose pulley abnormalities with different imaging modalities. MATERIALS AND METHODS: Three groups of cadaveric fingers underwent computed tomography (CT), magnetic resonance (MR) imaging, and ultrasonography (US). The normal anatomy of the pulley system was studied at extension and flexion without and with MR tenography. Pulley lengths were measured, and anatomic correlation was performed. Pulley lesions were created and studied at flexion, extension, and forced flexion. Two radiologists reviewed the studies in blinded fashion. RESULTS: MR imaging demonstrated A2 (proximal phalanx) and A4 (middle phalanx) pulleys in 12 (100%) of 12 cases, without and with tenography. MR tenography showed the A3 (proximal interphalangeal) and A5 (distal interphalangeal) pulleys in 10 (83%) and nine (75%) cases, respectively. US showed the A2 pulley in all cases and the A4 pulley in eight (67%). CT did not allow direct pulley visualization. No significant differences in pulley lengths were measured at MR, US, or pathologic examination (P: =.512). Direct lesion diagnosis was possible with MR imaging and US in 79%-100% of cases, depending on lesion type. Indirect diagnosis was successful with all methods with forced flexion. CONCLUSION: MR imaging and US provide means of direct finger pulley system evaluation.

Anatomical considerations regarding the posterior interosseous nerve during posterolateral approaches to the proximal part of the radius.

BACKGROUND: The purpose of our study was to quantify the dimensions of a surgically safe zone along the proximal part of the radius, from the posterolateral aspect. METHODS: The posterolateral approach between the anconeus and the extensor carpi ulnaris was performed in thirty-two cadaveric specimens, and the posterior interosseous nerve was exposed. Forearms were measured from the radial styloid process to the radiocapitellar joint. The distance from the capitellum to the point where the posterior interosseous nerve crossed the radial shaft and the angle between the nerve and the shaft were measured with forearms in pronation and supination. RESULTS: Pronation of the forearm allowed safe exposure of at least the proximal thirty-eight millimeters of the lateral aspect of the radius, with an average proximal safe zone of 52.0 +/- 7.8 millimeters. Supination decreased this proximal safe zone to as little as twenty-two millimeters and an average of 33.4 +/- 5.7 millimeters. The angle formed by the posterior interosseous nerve and the radial shaft in supination averaged 47.4 +/- 6.8 degrees; this decreased to 27.8 +/- 6.7 degrees with pronation. CONCLUSIONS: Approaching the lateral aspect of the proximal part of the radius is safest in pronation.

Surgical reconstruction of acquired spastic foot and ankle deformity.

With the aging population and improved methods of emergency transport, the number of surviving stroke and brain injury patients continues to increase. Aggressive rehabilitation of appropriate candidates is justified. In the period of spontaneous recovery, efforts are made to prevent fixed contractures using passive mobilization, splinting, nerve blocks, and electrical stimulation. If deformity persists and the patient is no longer recovering, operative management can help alleviate the functional and hygiene problems associated with these limb deformities.

Treatment of shoulder deformity in acquired spasticity.

Cerebrovascular accidents and traumatic brain injury produce most of the deformities seen in patients with spastic imbalance of the shoulder. A general awareness of the global neurologic defect is required to understand appropriate treatment alternatives. Conservative treatment techniques include early initiation of therapy exercises. Muscle or nerve block treatments may prevent severe shoulder contractures. Diagnostic blocks may help differentiate between deformity caused by spasticity and that caused by fixed soft tissue contracture. Operative release procedures are described. These operations, when combined with appropriate postoperative therapy programs, permit correction of contractures caused by unbalanced muscle forces around the shoulder in patients with severe spasticity who do not respond to conservative care.

Definitions and terminology of compartment syndrome and Volkmann's ischemic contracture of the upper extremity.

Increased tissue pressure within the confines of a nondistensible anatomic compartment increases venous pressure, causes vascular compression, decreases the arteriovenous gradient, and results in a compartment syndrome. The decreased blood flow and hypoxia result in cellular damage of muscles, nerves, and vascular endothelium. Richard von Volkmann's legacy has taught us that a patient's overall status must be monitored to follow the systemic determinants of peripheral blood flow and oxygen transport. Limbs must also be monitored with vigilance. A high index of suspicion must always be present, and compartment pressures can be measured directly to aid in clinical decision making regarding the status of a compartment. The remaining articles in this issue describe and explore von Volkmann's syndrome using the terms and concepts introduced here.

Acute compartment syndrome of the forearm.

The forearm is the most common site for compartment syndrome in the upper extremity. The three compartments of the forearm include the volar (anterior or flexor), the dorsal (posterior or extensor), and the mobile wad. Both-bone forearm fractures and distal radius fractures are common initial injuries in adults that lead to acute forearm compartment syndrome. Supracondylar fractures, especially those with associated vascular injuries, are frequent causes of compartment syndrome in children. The flexor digitorum profundus and flexor pollicis longus are among the most severely affected muscles because of their deep location, adjacent to bone. Initial treatment consists of removal of occlusive dressings or splitting or removal of casts. If symptoms do not resolve rapidly, fasciotomy is indicated. Decompression fasciotomy of the forearm is performed through volar or dorsal approaches. The medial nerve is decompressed throughout its course, including high-risk areas deep to the lacertus fibrosus; between the humeral and ulnar heads of the pronator teres, the proximal arch, and deep fascial surface of the flexor digitorum superficialis; and the carpal tunnel.

Crush syndrome of the upper extremity.

Crush syndrome is the severe systemic manifestation of prolonged muscle compression and compartment syndrome. Careful patient assessment, early diagnosis, and aggressive treatment are vital to prevent multiorgan failure and death. Medical management of systemic complications, along with operative procedures of fasciotomy and debridement, are indicated with accompanying compartment syndrome. Debridement of necrotic and nonviable tissue is necessary; significant risks of infection and hemorrhage remain until the wounds can be subsequently closed or covered with skin graft. Crush syndrome and muscle necrosis in a closed injury without compartment syndrome may be followed clinically until healing or demarcation of a gangrenous part occurs, providing the patient's general medical condition, including renal function, can be maintained. Fasciotomy and hyperbaric oxygen will not reverse necrosis of muscle in the absence of compartment syndrome and therefore do not affect outcome of the extremity. Overall, prognosis is improved by early diagnosis and treatment, but outcome of the crushed extremity is poor and Volkmann's contracture often results.

Exertional compartment syndrome of the upper extremity.

Exertional compartment syndrome is characterized by intracompartmental pressures that rise transiently following repetitive motion or exercise, thereby producing temporary, reversible ischemia, pain, weakness, and, occasionally, neurologic deficits. The exact cause or pathogenesis remains unclear; a disturbance of microvascular flow caused by elevated intramuscular pressure leads to tissue ischemia, depletion of high-energy phosphate stores, and cellular acidosis. Anatomic contributing factors may include a limited compartment size, increased intracompartmental volume, constricted fascia, loss of compartment elasticity, poor venous return, or increased muscle bulk. The diagnosis is suspected based on history and confirmed with physical examination and intramuscular pressure evaluation before and after exercise (stress test). Differential diagnosis includes claudication or other vascular abnormalities, myositis, tendinitis, periostitis, chronic strains or sprains, stress fracture, other compression or systemic neuropathies, and cardiac abnormalities with angina or referred extremity pain. Initial treatment includes activity modification; refractory symptoms can be managed with elective fasciotomy.