Houssay and biomedical research

The possible algogenic effects of elevated serum endothelin levels in cardiac syndrome X were investigated in a case-control study that examined somatic pain perception in the forearm during submaximal effort tourniquet and cold immersion tests. Pain threshold to both ischemic and cold stimulation of the forearm was demonstrated to be significantly lower in patients with syndrome X than in matched healthy controls, and a negative correlation between ischemic pain threshold and endothelin levels was demonstrated.     

Neonatal compression ischaemia of the forearm

A case of neonatal compartment syndrome of the forearm is reported. The cause was thought to be compression during delivery. It not only caused muscle contractures but also affected bone growth. Conservative treatment was given. At the age of 6 years, the muscle contracture had recovered and there was full hand function, but there was growth arrest of the distal radial epiphysis and the affected forearm was shorter than the other.     

Randomized study of chemotherapy and surgery versus radiotherapy for stage IIIA non-small-cell lung cancer: a National Cancer Institute of Canada Clinical Trials Group Study

We treated two children with the unusual complication of ulnar nerve palsy after closed both-bone forearm fractures. Both patients developed an ulnar claw-hand deformity within 7 weeks of injury that resolved spontaneously by 20 weeks postinjury with nonoperative treatment. No patient showed any signs or symptoms of an ischemic compartment syndrome. Both nerve injuries were identified immediately at the time of fracture by a careful neurologic examination. This avoids confusion with a postreduction nerve entrapment injury or ischemic injury after a localized compartment syndrome, which may have considerably different treatments and outcomes. We recommend that a careful neurologic examination be recorded before any manipulative reduction of forearm fractures in children. If an ulnar nerve palsy is detected, it is probably a result of nerve contusion and should resolve without the need for surgical exploration.     

CD9, but not other tetraspans, associates with the beta1 integrin precursor

Insulin resistance is common in patients with angina pectoris, a positive exercise electrocardiogram, and normal coronary angiograms (syndrome X). It is still not known whether insulin resistance affects the cardiac muscle itself and, if so, whether insulin resistance involves myocardial hemodynamics and energy metabolism. We investigated hemodynamics as well as metabolite exchanges across the heart and the forearm in eight patients with syndrome X and eight control subjects during a baseline period after an overnight fast and during a hyperinsulinemic-euglycemic clamp. Myocardial hemodynamics and metabolism were studied at rest, during pace stress, and in the recovery period after pacing. Neither coronary sinus blood flow nor forearm blood flow differed between the groups before and during the clamp. Whole body insulin-stimulated glucose uptake was decreased in the patients (15.6+/-2.1 vs. 23.1+/-2.0 micromol x kg-1 x min-1). Insulin-stimulated glucose uptake in the forearm and the cardiac muscle was equally reduced in the patients (46+/-5 and 48+/-5%). Myocardial glucose uptake correlated with total arterial delivery in the control subjects (r = 0.63, P < 0.01), but not in patients (r = 0.22, P = 0.13). Carbohydrate and lipid oxidation was similar in the two groups at rest, and changes during the clamp were not different in control subjects and patients either at rest, during pacing, or in the recovery period. Patients with syndrome X exhibit myocardial insulin resistance, but cardiac energy metabolism remains unaffected. In patients with syndrome X, insulin-stimulated glucose uptake is independent from myocardial blood flow.     

Gustatory sweating in a free flap

A case of Frey's syndrome arising in a free radial forearm flap used to reconstruct a defect in the parotid region is reported. To our knowledge, Frey's syndrome, although common following parotidectomy, has not been reported in a free flap. It is possible that parasympathetic secretomotor fibres gained access to the fasciocutaneous flap via the cutaneous nerve stumps in its edge, resulting in gustatory sweating.     

The significance of the three volar spaces in forearm compartment syndrome: a clinical and cadaveric correlation

The goal of this study was to assess the importance of the 3 volar spaces in forearm compartment syndrome in a prospective manner. A cadaveric model was developed to correlate with our clinical experience. All but 1 of 21 volar compartments (superficial volar, deep volar, and pronator quadratus spaces) in 7 patients in our clinical series decompressed adequately after release of the superficial volar fascia. One patient needed further release of the pronator quadratus compartment; he had suffered a combined crush and vascular injury. All volar compartments in our cadaveric model decompressed with superficial fasciotomy. Prefasciotomy and postfasciotomy pressures should be obtained from all 3 compartments of the volar forearm. Superficial fasciotomy usually adequately decompresses the entire volar forearm; however, in the event that deep compartment pressures remain high after superficial fasciotomy, release of the affected space is indicated.     

Reconstruction of the loss of bone substance of the forearm by cubitalization of the radius (one bone forearm). Apropos of 6 cases

Extensive forearm bone loss, whatever its etiology, presents a difficult reconstruction problem. This is mainly the case in the presence of lesions of the interosseous membrane associated with the radio-ulnar joint. When preservation of forearm rotation is not possible, cubitalization of the radius and reconstruction of the forearm by creation of a "one bone forearm" seems to be an excellent salvage technique both functionally and cosmetically. Our experience concerns six clinical cases; two of these cases are original and give the authors the opportunity to describe a new reconstructive technique of the distal humerus and elbow by vascularized transfer of the radius onto the radial artery (with a cutaneo-osseous transfer in one case). The etiology of the bone defect included severe trauma in three cases, and a Volkman's syndrome complicated by osteomyelitis in one case. Two cases represent an original technique of reconstruction of the distal humerus by a vascularised transfer of the radius onto the radial artery. Forearm reconstruction is performed by cubitalization of the radius. The etiology was traumatic in one case and neoplastic in another, and a cutaneo-osseous transfer was performed in the latter case. In this difficult problem of bone reconstruction, a favorable functional and cosmetic result was obtained in our series.     

The 4S study: a critical review

A 24 year old combat medic was admitted to the field hospital at Tomislavgrad in Bosnia, with a suspected forearm, fracture. Radiographs did not show any bony injury. Clinical examination showed marked swelling and tenderness over the extensor compartment. The pain became more severe over the following 12 hours with the pain becoming most intensely felt in the extensors on passive extension. Fasciotomy for suspected acute compartment syndrome was carried out. Acute compartment syndrome is a common complication of extremity injury, and is a clinical diagnosis which should be suspected in all injuries with marked swelling and severe pain.     

Compartment syndromes of the hand

We retrospectively reviewed the records of nineteen patients who had been managed with fasciotomy because of compartment syndrome of the hand. The patients were five months to sixty-seven years old and included ten adults and nine children. Seventeen patients were followed for an average of twenty-one months (range, one to fifty-eight months), one patient was lost to follow-up after discharge, and one patient died four days postoperatively. All of the patients had a tense, swollen hand and elevated pressure in at least one interosseous compartment. Eight patients also had a compartment syndrome of the forearm. The compartment syndromes developed after intravenous injections (eleven patients); after a gunshot wound, a crush injury, or a complication related to the use of an arterial line (two patients each); and after a complication related to an arthrodesis of the wrist or a crush injury due to prolonged pressure on the upper extremity secondary to a drug overdose (one patient each). Fifteen patients had an obtunded sensorium-either because of a serious illness or injury or secondary to prolonged anesthesia-when the compartment syndrome was recognized. In thirteen of these patients, including eight children and five adults, the compartment syndrome developed because of a complication related to the intravenous or intra-arterial administration of drugs. Carpal tunnel release and decompression of the involved compartments led to a satisfactory result for thirteen of the seventeen patients who were followed. The remaining four patients (including two children who had an amputation, one child who had impaired function of the hand secondary to brain damage, and one adult who had extensive involvement of the forearm and complete loss of function of the hand) had a poor result. All four of these patients had been obtunded when the compartment syndrome developed. The treating physician should maintain a high index of suspicion for a compartment syndrome of the hand when managing seriously ill, obtunded patients-particularly children-who are receiving multiple intravenous or intra-arterial injections.     

Anterior interosseous nerve syndrome presenting with pronator teres weakness: a case report

Anterior interosseous nerve syndrome (AINS) has been well described. A key muscle to examine clinically and on electromyography is the pronator teres, as this can differentiate between forearm and more proximal entrapment sites. We present a case of AINS with marked weakness and denervation of pronator teres. At operation the anterior interosseous nerve gave rise to the nerve to pronator teres and was entrapped by a fibrous band from the deep head of pronator teres.     

Surgical management of the substernal thyroid gland

Compartment syndromes occurring in the forearm and leg are not infrequent. However, reports of compartment syndrome of the upper arm are conspicuously rare. Inferior dislocation of the shoulder combined with compartment syndrome has rarely been reported in the literature. We report our experience with a patient with inferior dislocation of the glenohumeral joint combined with compartment syndrome of the upper arm. A 29-year-old man had traumatic inferior dislocation of the glenohumeral joint combined with severe swelling of the shoulder and upper arm. After close reduction, the shoulder and upper arm were still tensely swollen. Compartment pressure of the upper arm was measured using a digital manometer (Quick Pressure Monitor 295-1, Stryker) and remained very high, thus, fasciotomy was performed. After debridement and skin graft, the arm healed without sequelae. When a patient has a fracture dislocation of the shoulder joint associated with a swollen arm, compartment syndrome of the upper arm should be included as a differential diagnosis. Detecting the compartment pressure can confirm the diagnosis of compartment syndrome objectively.     

Proximal hypospadias

Entrapment of the median nerve in the proximal forearm, the so-called pronator syndrome, is considered a rather rare condition but it is four times more common in women than in men. In this study, 23 of 30 female machine milkers with symptoms in the forearm and hand were clinically diagnosed as having the pronator syndrome. The diagnosis of median nerve involvement was based on the clinical history and on physical examination by a hand surgeon. All 23 milkers complained of aching in the volar part of the forearm and had a sensation of numbness, tingling, and decreased muscle strength in their hands, mostly in the hands which usually were statically loaded with heavy equipment. Objectively, all had an experience of tenderness over the pronator teres muscle. Furthermore, they showed reduced muscle strength, especially in the following muscles: pronator teres (PT), flexor carpi radialis (FCR), flexor pollicis longus (FPL), and flexor digitorum profundus II (FDP II). To validate the manual muscle testing, Mannerfeldt's intrinsicmeter was used to quantify the clinically observed weakness. Eight of the 23 milkers with pronator syndrome were surgically released from neuropathy and were almost symptom-free at follow-up after six months. One patient had a slight sensation of numbness and had to be given surgical carpal tunnel release later on. The external exposure of the arm during the application of the milking cluster probably causes muscle and fascial tensions that induce compression of the nerve. Further studies are needed to establish the level of the internal exposure.     

The gluteal compartment syndrome

The gluteal compartment syndrome is a rare, often unrecognized condition which, left untreated, can lead to renal failure, sepsis, and death. The etiology, physiology, and manifestations are similar to those seen in the more common and readily recognized compartment syndromes of the lower leg and forearm. The large gluteal muscle mass confined by the fascia lata of the thigh and tensor fascia lata can, under the right conditions, produce muscle necrosis, acidosis, elevations of creatinine phosphokinase, and ultimately renal failure. A gluteal compartment syndrome most commonly occurs in individuals with an altered mental status due to drugs or alcohol who remain in one position for an extended period of time. This prolonged compression leads to muscle damage, edema, and a full-blown compartment syndrome. Due to its anatomic location and rarity, diagnosis is missed or delayed, resulting in significant morbidity and possible mortality. The mainstay of treatment consists of fasciotomy and debridement.     

Müllerian duct cyst masquerading as chronic prostatitis: diagnosis with magnetic resonance imaging using a phased array surface coil

A retrospective study was designed to verify how often an anatomic variation caused the radial sensory nerve entrapment at the forearm (Wartenberg's syndrome). This variation, in which the superficial branch of the radial nerve emerges from under the fascia between two slips of a split brachioradialis tendon, was mentioned once in a clinical textbook as a basis for nerve entrapment but was found to occur in 5 of 150 dissected arms in 4 of 75 cadavers (3.3% of the investigated arms) in a recent anatomic study. To evaluate the incidence of this variation, 143 operative reports from patients who had Wartenberg's syndrome were reviewed. The variation was observed in seven patients. We conclude that any operation for Wartenberg's syndrome should include a thorough investigation of the site where the radial sensory nerve emerges from under the fascia and, if the nerve emerges through a split brachioradialis tendon, the anomalous tendon slip should be divided.     

Change in bacterial community during biodegradation of aniline

A modification of the standard electrodiagnostic test was developed in an effort to provide a more sensitive electrodiagnostic evaluation in radial tunnel syndrome. Radial motor nerve latency recordings were obtained in 3 different forearm positions: neutral, passive supination, and passive pronation. The maximal difference in these recordings, the differential latency, in 25 patients with radial tunnel syndrome of greater than 6 months duration (test group) was compared with those in 25 asymptomatic volunteers (control group). Differential latency recordings were obtained in all patients in the test group before and after surgery. Radial nerves that were compressed demonstrated a significantly greater differential latency (0.44+/-0.12 ms) versus controls (0.12+/-0.008 ms). Following radial nerve decompression, differential motor latencies in the test group decreased below control values, demonstrating a resolution of the provoked electrical response with a postoperative differential latency of 0.07+/-0.05 ms. Our results demonstrate the differential motor latency of the radial nerve to be a sensitive electrodiagnostic tool in patients with radial tunnel syndrome. A differential latency of > or =0.30 ms was considered indicative of radial tunnel syndrome.     

Effect of sodium bicarbonate amount on in vitro indomethacin release from self-setting carbonated-apatite cement

We describe our surgical technique of acute pediatric forearm lengthening and joint leveling for treatment of symptomatic forearm-length discrepancies. A retrospective clinical and radiographic analysis was performed of all patients undergoing acute forearm lengthenings of > 1.0 cm between 1983 and 1993. Twenty-four acute forearm lengthenings were reviewed with an average follow-up of 3 years. The diagnosis included osteochondromatosis in 17 patients, growth arrest in four patients, and skeletal dysplasia in three patients. Surgical indications included progressive forearm or wrist deformity, significantly limited or painful forearm rotation, or radial-head subluxation. The average lengthening was 1.5 cm (range, 1.0-2.3), which was 9% of total length (range, 3-20%). The goal for lengthening and wrist-joint leveling was near-neutral ulnar variance and was achieved in all cases. We conclude that the forearm can be lengthened acutely successfully to achieve near-neutral ulnar variance in children with forearm-length discrepancies caused by osteochondromas, growth arrests, or bone dysplasias. The surgical technique and the results are described in 24 forearm lengthenings.     

Compartment syndromes in obtunded patients

A high index of suspicion for a compartment syndrome in the upper extremity should be maintained in all obtunded patients who are at risk for the condition. Obtunded patients are those with a dulled or altered physical or mental status secondary to injury, illness, or anesthesia; those with diminished or absent sensation in the upper extremity because of nerve injury or anesthesia; and those whose ability to communicate is impeded, such as infants and young children and the mentally ill or disabled. These patients represent a vulnerable group whose inability to demonstrate the hallmark symptoms and signs of the syndrome puts them in jeopardy of a late diagnosis of a compartment syndrome and its potentially devastating sequelae. The most likely causes of a compartment syndrome in this population are skeletal or soft-tissue trauma, prolonged limb compression, thrombolytic therapy after myocardial infarction, arterial or intravenous fluid administration, and upper extremity Surgery. Whenever a compartment syndrome of the hand, forearm, or upper arm is suspected, the obtunded patient should be examined closely and frequently, and any changes over time should be documented carefully. Intracompartmental pressure measurement provides a useful adjunct to the physical examination and history in these patients and may be diagnostic if other symptoms and signs are obscured. Once the compartment syndrome is diagnosed, emergent fasciotomy is indicated. To avoid a loss of function in the obtunded patient, special care must be taken postoperatively to assure that early motion exercises are carried out.     

Shigella and the fluorinated quinolones

An 8-year-old girl presented with marked shortening of the right forearm due to destruction of both the radius and ulna secondary to neonatal osteomyelitis. A one-bone forearm operation was performed to achieve a stable forearm. Two years later, the one-bone forearm was lengthened for 6 months by callus distraction (callotasis) achieving 12 cm of extra length. The patient was last followed up at the age of 16. The appearance and functional outcome of the right upper limb had been improved and she was independent in all activities of daily living.     

Fracture of the radial forearm osteocutaneous donor site

Since the introduction of the osteocutaneous radial forearm flap in 1983, fractures of the radius have been reported to occur in approximately 30% of cases. Fracture of the donor forearm has been the cause of the most significant morbidity, and the difficulty in management of these fractures has been reported. We report our experience in managing three fractures involving the donor forearm. Optimum results can be achieved by early stabilization with external fixation and vascularized bone grafting. Excessive resection of the radius should be avoided and alternative sources of vascularized bone used to avoid mutilation of the forearm.     

Rupture of Valsalva''s sinus of subacute development

In this study, the effects of forearm static exercise were determined on local blood flow and oxygen consumption in 15 normal individuals (NL) and their responses were compared with ten patients in congestive heart failure (CHF). Forearm blood flow was determined by a plethysmographic technique before and during 15% of maximum voluntary contraction of the forearm. Regional arterial and venous oxygen contents were sampled and forearm oxygen consumption calculated by the Fick principle. At rest, forearm blood flow was less in patients with heart failure than in normal individuals; however, this was compensated for by an increased oxygen extraction, thus maintaining forearm oxygen consumption at a normal level. In contrast, during static exercise, forearm blood flow failed to rise normally with heart failure (NL 9.31; CHF 4.35 ml/min-100 ml, P less than 0.001) and the increased oxygen extraction was not sufficient to maintain a normal forearm oxygen consumption (NL .82; CHF .44 ml/min-100 ml, P less than 0.01). Therefore, patients with congestive heart failure demonstrate regional circulatory and metabolic abnormalities during static exercise that are comparable to those present during dynamic exercise. Because of a limited ability of their skeletal muscle resistance vessels to respond to dilator stimuli, they have an attenuation of their exercise hyperemia which leads to an earlier shift to anaerobic metabolism.