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Biomedical subjects

V L Young

Publications and source records attributed to V L Young.

At least 73 records · Page 4Linked to original sources
PubMed1991

Effect of breast implants on mammography.

We developed an experimental, reproducible method of evaluating the radiographic characteristics of breast implants in vitro using a mammographic phantom and a cadaver. Implant shells tested included smooth silicone, textured silicone, and silicone coated with polyurethane foam. Each type of shell was subsequently filled with saline, silicone gel, and peanut oil; the images were recorded radiographically. Textured silicone and smooth silicone shells minimally impair detection of artifacts. Polyurethane-coated shells are less radiolucent but allow visualization of some microcalcifications. Saline and silicone-gel-filled implants are radiopaque regardless of shell type. Textured silicone and smooth silicone shells filled with peanut oil are radiolucent and allow visualization of microcalcifications and most soft-tissue masses. These data demonstrate that radiolucent breast implants are possible, and further efforts are under way to achieve Food and Drug Administration approval for clinical testing.

Breast↗
PubMed1990

Coincident rupture of the scapholunate and lunotriquetral ligaments without perilunate dislocation: pathomechanics and management.

Wrist injuries causing coincident disruptions of the scapholunate and lunotriquetral ligaments commonly result in perilunate dislocations. This article (1) describes our management of eight patients with wrist pain after coincident scapholunate and lunotriquetral ligament disruptions in the absence of perilunate dislocation; and (2) reports the results of biomechanical testing of some of the extrinsic and intrinsic wrist ligament and interprets these data to explain the injury seen clinically. The diagnosis of ligament failure was made on the basis of history, physical examination, arthrography and surgical exploration. Surgical treatment of seven patients consisted of concomitant scapho-trapezio-trapezoid fusion and lunotriquetral fusion. Three of seven patients were free of pain, two had pain only at the extremes of motion, and two required additional surgery. Biomechanical analysis of the scapholunate and lunotriquetral ligaments and two extrinsic wrist ligaments, the radiolunotriquetral and the radioscaphocapitate, confirmed the clinical suspicion that the intrinsic ligaments could be completely disrupted while the extrinsics are only partially injured. Such a scenario could account for the residual stability that prevents the development of perilunate dislocations. Coincident disruption of the scapholunate and lunotriquetral ligaments in the absence of perilunate dislocation is an unusual injury. Treatment with lunotriquetral fusion and scapho-trapezio-trapezoid fusion restored functional use in five of seven wrists while maintaining wrist motion.

Adult↗
PubMed1990

Intracerebral hematoma complicating split calvarial bone-graft harvesting.

A case is reported of an intracerebral hematoma following the harvest of split calvarial bone. Full recovery by the patient occurred. Complications following calvarial bone graft harvest are reviewed. Potential devastating complications warrant serious consideration of alternative sources of bone, especially in the purely elective surgical candidate.

Adult↗
PubMed1990

Skin grafting: dermal components in inhibition of wound contraction.

The inhibition of wound contraction by skin grafting is widely accepted but poorly understood. We used an experimental model of contraction to study the effect of dermal organization, cellularity, and collagen matrix on contraction inhibition. Wound beds covered with inverted and collagen matrix grafts contracted at the same rate as full-thickness grafts. Heat denaturation diminished this ability. Partial-thickness grafts derived from papillary or reticular dermis inhibited contraction to an equal degree. Inhibition of contraction appears to relate to the amount of intact dermal collagen matrix transferred, and not to another component of a full-thickness graft.

Animals↗
PubMed1990

Stenosing flexor tenosynovitis.

A review of 253 consecutive digits with stenosing flexor tenosynovitis was done to clarify the respective role of steroid injection and surgical release in the management of stenosing flexor tenosynovitis. Treatment selection was based on the patient's age and severity of presenting complaints. In patients aged 10 years or more, analysis showed no statistically significant difference between results with steroid injection and surgical release. Surgical treatment was associated with higher cost and more complications. Based on this review, we recommend up to three injections of 20 mg of triamcinolone into the digital flexor sheath as the initial management of nonlocking, stenosing flexor tenosynovitis in adults. Initial management by surgical release is reserved for children and patients with digits locked in flexion.

Adolescent↗
PubMed1990

Surgical management of palmar hyperhidrosis.

Hyperhidrosis is an idiopathic pathologic condition characterized by excessive sweating beyond that required to cool the body. Disturbance of the central nervous system, endocrine system, or obesity has been associated with this condition. Patients have a history of several years of occupational or social embarrassment. Individuals of Japanese ancestry and Jews of Northern African, Yemeni, or Balkan descent are predisposed to the condition. Nonoperative therapy is merely temporizing and unacceptable because of lack of efficacy or side effects. Surgical intervention provides effective and permanent control. The key to surgical correction appears to be the division of the sympathetic chain above the T-2 ganglion and below the T-3 ganglion of the involved side with removal of the entire T2-3 segment with its corresponding spinal nerves. This paper presents our experience with the dorsal thoracic approach for interruption of sympathetic innervation for severe palmar hyperhidrosis. We also review surgical efficacy of various approaches to the sympathetic chain, as well as possible side effects of operative intervention.

Adult↗
PubMed1990

Wrist pain: a systematic approach to diagnosis.

Numerous radiographic procedures are now available to help determine the cause of wrist pain. This paper presents a wrist-pain algorithm that defines the relative roles of various radiographic techniques in the evaluation of patients with wrist pain. Practical application of the algorithm is demonstrated through illustrative cases.

Adult↗
PubMed1990

The relationship of retrobulbar hematomas to vision in cynomolgus monkeys.

An experimental model has been developed to measure the effect of retrobulbar hematomas on functional vision in cynomolgus monkeys. In this model, functional vision was quantitated using flashed evoked visual potentials in five monkeys following creation of retrobulbar hematomas. In one monkey used as a control, functional vision remained impaired for 180 minutes following induction of retinal ischemia by increased intraorbital pressure. In two monkeys in which increased intraorbital pressure was relieved by anterior chamber paracentesis following 15 minutes of retinal ischemia, flashed evoked visual potential promptly returned to baseline level. In two additional monkeys in which increased intraorbital pressure was relieved following 30 minutes of retinal ischemia, flashed evoked visual potentials improved but never returned to baseline levels. This study demonstrates the usefulness of flashed evoked visual potentials in measuring functional vision in cynomolgus monkeys. This experimental model should prove useful in evaluating the effects of increased intraorbital pressure on functional vision and the effect of intervention on impaired vision due to retrobulbar hematomas. Further studies with larger numbers of animals are needed to clarify these preliminary studies and document longer-term effects of retinal ischemia secondary to retrobulbar hematomas.

Animals↗
PubMed1989

Management of chronic lunotriquetral ligament tears.

Treatment of chronic disruptions of the lunotriquetral (LT) ligament is not well-defined. Eleven patients treated by LT fusion with use of a compression screw are reported. The injury frequently resulted from hyperextension of the wrist. Pain on the ulnar side of the wrist, limited motion, and tenderness over the LT joint exacerbated by ballottement were present. Standard radiographs were normal. Arthrography showed the ligamentous tear in all cases. After operation, immobilization was continued until fusion was apparent radiographically. Fusion was achieved in all cases between 2 and 5 months. Four patients were free of pain, four patients had pain only at the extremes of motion, and three patients had persistent pain. Mean wrist motion was as follows (preoperative/postoperative): flexion (53 degrees/45 degrees), extension (60 degrees/49 degrees), radial deviation (17 degrees/21 degrees), and ulnar deviation (25 degrees/18 degrees). Maximum grip strength as a percentage of the uninjured side was 73% preoperatively and 59% postoperatively. LT tears can exist de novo or as part of the ulnar impaction syndrome; a method for differentiation is presented.

Adult↗
PubMed1989

Fluctuation in grip and pinch strength among normal subjects.

Grip and pinch strength testing are commonly used to evaluate hand strength for disability ratings and to assess responses to various forms of therapy. This study determined the variations in grip and pinch strength in normal individuals. Ninety-five healthy subjects--61 women and 34 men--were examined prospectively by use of a Jamar dynamometer and a Preston pinch gauge. Grip and pinch were measured in the morning and afternoon twice a week for 3 weeks, giving a total of 12 testing periods. Mean grip strength fluctuated between 5.1 and 8.4 kg, or between 19.2% and 23.7%. Mean lateral pinch strength fluctuated between 2.6 and 3.8 pounds, or between 13.8% and 17.6%. There were no differences between the morning and afternoon values. Grip and pinch strength fluctuate over time. Repeat testing is necessary to accurately assess hand strength. Grip and pinch strength do not vary from morning to afternoon.

Adolescent↗
PubMed1989

Effect of anterior chamber paracentesis on decreased retinal circulation due to retrobulbar hematoma in dogs.

An experimental canine model for blindness following blepharoplasty was developed to demonstrate occlusion of retinal circulation resulting from simulated retrobulbar hematoma. Seven mongrel dogs were studied, monitoring retinal vascular patterns by funduscopic examination and intraocular pressure by pneumotonometry. Anterior chamber paracentesis was performed in five dogs 10 minutes after injecting blood retrobulbarly, with an immediate decrease in pressure and return of retinal blood flow. In two dogs without paracentesis, increased pressure and blindness persisted. Anterior chamber paracentesis has been shown to reduce intraocular pressure from hematoma of the retro-orbital area in dogs. Although controversial, anterior chamber paracentesis may represent a useful temporizing adjunct in the treatment of increased intraocular pressure and impaired vision from hematoma following blepharoplasty.

Animals↗
PubMed1989

Calcification of breast implant capsule.

We have presented a case of bilateral capsular calcification, an extremely rare but clinically important complication of augmentation mammoplasty. Little is known about its pathogenesis, but it is believed to be related to the presence of molecular silicone and/or Dacron patches in the pericapsular environment. This condition may mask calcifications of the breast due to carcinoma, and it often exacerbates the symptoms of capsular contracture. We recommend removal of the calcified capsules and replacement of the implants in the submuscular position.

Breast Diseases↗
PubMed1989

Management of scaphoid fractures: a review and update.

The scaphoid is the most commonly injured carpal bone. Almost half of all bony wrist injuries involve the scaphoid. Treatment is controversial and, when inadequate, can result in a painful nonunion or degenerative radiocarpal arthritis. Fracture of the scaphoid occurs most often in young adult men, with a peak incidence between the ages of 15 and 30 years. The scaphoid is less susceptible to fracture during the phase when it is mostly cartilaginous, thus making scaphoid fracture rare in childhood. In this article, we review current treatment of fracture of the scaphoid and examine controversial topics in its management.

Adolescent↗
PubMed1989

Plasma lidocaine levels during augmentation mammaplasty and suction-assisted lipectomy.

Many plastic surgical procedures are dependent on or aided by the use of local anesthetics. Drug toxicity, although uncommon, is the most feared complication of this technique. There are multiple factors that lead to varying drug levels. These include drug concentration, speed of injection, rate of degradation, total dosage, site of injection or application, rate of administration, and the adjunctive use of vasoconstrictors. This study evaluates the use of subcutaneously injected lidocaine in patients undergoing suction-assisted lipectomy and augmentation mammaplasty. Lidocaine in the concentration of 0.5% containing either 1:100,000 or 1:200,000 epinephrine was used in doses up to 500 mg. Serial lidocaine levels were then obtained up to 1 1/2 hours after injection utilizing two different assay techniques. Our findings demonstrate consistently nondectable serum lidocaine levels despite the use of doses in excess of recommended "safe" amounts. This suggests that under specific circumstances and with certain operative procedures, lidocaine dosing can be liberalized.

Adipose Tissue↗
PubMed1989

The effect of breast implants on the radiographic detection of microcalcification and soft-tissue masses.

Current implants for breast augmentation containing silicone gel, saline, or both can totally obscure mammographic detection of microcalcifications and soft-tissue masses. To investigate the possibility of developing a more radiolucent implant, radiographs were obtained of silicone shells that contained silicone gel, saline, silicone gel and saline, polyurethane-covered silicone gel, gelatin, sunflower oil, and peanut oil. All radiographs were obtained using a Siemens Mammomat by placing the implant over an American College of Radiology mammography phantom. Results were measured by the ability to visualize or resolve the artifacts in the mammography phantom. The silicone shell alone minimally altered artifact resolution. Silicone shells filled with silicone gel, silicone gel and saline, saline alone, polyurethane-covered silicone gel, and gelatin were equal in radiodensity and completely obscured all phantom artifacts. Silicone shells filled with peanut oil and sunflower oil had equal radiodensity and allowed visualization of large microcalcifications and some soft-tissue masses. Current implants used for augmentation mammaplasty can totally obscure mammographic detection of microcalcifications and soft-tissue masses. A more radiolucent breast implant is possible, and further research is needed to define the best filler material and test its biocompatibility.

Breast↗
PubMed1988

Role of radionuclide imaging in the evaluation of wrist pain.

The cause of hand and wrist pain can be difficult to determine, especially when standard radiographs are normal or show only nonspecific changes. This study reports the effectiveness of radionuclide imaging in the evaluation of patients with hand and wrist pain of uncertain cause. Eighty-eight patients with hand and wrist pain and initially normal standard radiographs were evaluated prospectively by additional radiographic methods including the following: routine tomography, wrist arthrography, computerized tomography, or magnetic resonance imaging. Each patient also had bone scintigraphy. The diagnosis established by clinical assessment and by other imaging methods was then compared with the scintigraphic findings. The presence or absence of focal scintigraphic abnormalities correlated with the presence or absence of focal pathology definable by the conventional methods in 88% of patients. As expected, scintigraphy was chiefly of value in defining the locus of an injury or other process in the wrist, rather than the nature of an abnormality. The scintigrams were abnormal in 95% of cases involving complete intrinsic ligament ruptures and fractures and were normal in 96% of patients with no definable injury. Scintigraphic findings correlated poorly with partial intrinsic ligament injuries and in cases of synovitis. Radionuclide imaging is a sensitive means of detecting focal lesions in patients with hand and wrist pain of unknown cause.

Adult↗
PubMed1988

A case study of pyoderma gangrenosum.

Pyoderma gangrenosum is a rare neutrophilic dermatosis seen initially as painful pustules or bullae on the skin that rapidly ulcerate and have a characteristic raised, purplish areola surrounding them. It is often associated with inflammatory bowel disease and less commonly with other systemic diseases, such as myelofibrosis, rheumatoid arthritis, and chronic active hepatitis. Pyoderma gangrenosum involving the hand is a rare entity, with only two previous cases reported in the literature. This article describes a patient with myelofibrosis in whom pyoderma gangrenosum of the hand developed after she underwent splenectomy.

Aged↗