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Biomedical subjects

G M Rayan

Publications and source records attributed to G M Rayan.

At least 37 records · Page 2Linked to original sources
PubMed1999

Osteolipoma of the hand: a case report.

A 61-year-old, healthy woman presented with a six-month history of a mass on the radial volar aspect of her dominant right hand. The patient had a history of trauma to the hand six years previously. Radiographs showed a bony lesion in the index metacarpal shaft and the MRI showed a bony lesion and soft tissue mass suggestive of a parosteal lipoma. Surgical excision of the lesion revealed a lipoma overlying a bony exostosis or osteolipoma of the hand. Post-operatively, the patient's symptoms resolved and she had no recurrence of the tumor.

Bone Neoplasms↗
PubMed1998

Skin necrosis complicating functional bracing.

We report a complication associated with functional bracing of a metacarpal shaft fracture that required operative intervention. A 30-year-old man with a closed, dorsally angulated, metacarpal shaft fracture of the right ring finger was treated with a functional brace. During brace immobilization, the patient developed full-thickness skin necrosis on the dorsum of the right hand. The patient underwent surgical debridement of the ulcerated area and fracture stabilization with an intramedullary Kirschner wire. Patients treated with a metacarpal brace should be instructed to release the strap every 5 to 6 hours for a short period to allow restoration of blood flow to the potentially ischemic skin.

Adult↗
PubMed1998

Bowling related injuries of the hand and upper extremity; a review.

Bowling is one of the oldest and most popular indoor sports. The earliest evidence of bowling dates back to ancient Egypt. Archaeologists discovered equipment for a game resembling bowling. Modern forms of bowling appeared in England as early as the 1100s. Bowling can cause a variety of hand and upper extremity injuries either due to acute or reparative forces. Greater number of such injuries is being encountered as the popularity of the game has increased. The goal of this article is to present an overview of bowling related injuries, their mechanisms along with preventive and treatment measures.

Arm Injuries↗
PubMed1997

The extensor retinacular system at the metacarpophalangeal joint. Anatomical and histological study.

The anatomy of the sagittal bands was studied in 56 cadaver digits. The sagittal band is part of an extensor retinacular system which is integrated with the extrinsic and intrinsic musculotendinous structures. The extensor retinacular system is a single unit with radial and ulnar components and has transverse, sagittal and oblique fibres. The transverse-sagittal fibres, along with the palmar plate, form a closed cylindrical tube which surrounds the metacarpal head. The oblique fibres form the triangular lamina distal to the sagittal band. The radial component of the sagittal band is often thinner and longer than the ulnar component. The sagittal band envelops the extensor digitorum tendon and the superficial fibres are thinner than deep fibres, especially in the central digits. The central digits have palmar soft tissue confluence on each side consisting of the sagittal band, palmar plate, annular pulley and deep transverse metacarpal ligament. The sagittal band also appears to envelop the superficial interosseous tendons on both sides. Our findings explain the propensity for radial sagittal band injuries and suggest that the sagittal band is the primary stabilizer of the extensor digitorum at the metacarpophalangeal joint.

Adult↗
PubMed1997

Ligament reconstruction arthroplasty for trapeziometacarpal arthrosis.

Twenty-eight patients (30 thumbs) were evaluated after ligament reconstruction arthroplasty for trapeziometacarpal arthrosis. The mean patient age was 60 years, 86% were women, and the average follow-up period was 38 months. Subjective results showed excellent (40%) or good (57%) pain relief in 97% of patients. Return to previous work or activity level was achieved in 98%. Eighty-six percent of patients expressed overall satisfaction with the surgical outcome, mostly because of pain relief. Functional improvement was reported for many activities, except jar opening, which continued to be the most difficult task to perform. Thumb mobility improved, while key pinch strength showed an overall decrease of 27%. Proximal migration of the thumb metacarpal measured 27%, and radial subluxation was negligible. Thumb metacarpophalangeal joint hyperextension was present to some degree in more than 50% of patients before surgery and in 7 of 30 thumbs (23%) after surgery. Hyperextension was prevalent among women on hormone-replacement therapy, including 3 patients in whom these deformities recurred in spite of attempts to stabilize their joints during surgery.

Aged↗
PubMed1997

Scaphoid fractures in soccer goalkeepers.

The growing popularity of soccer in this country has led to an increasing number of soccer-related injuries. Epidemiologic studies report that soccer-related musculoskeletal injuries most frequently involve the lower extremities. These range from 56% to 95% of soccer injuries and player-to-player contact is the most common mechanism of injury. Upper extremity musculoskeletal injuries are less frequent, but have been reported, with goalkeepers being the most susceptible. There is a paucity in the literature regarding bony injuries about the wrist and hand among goalkeepers. The purpose of this article is to report three soccer-related scaphoid fractures and nonunions in two goalkeepers.

Adolescent↗
PubMed1996

Treatment of spastic thumb-in-palm deformity: a modified extensor pollicis longus tendon rerouting.

Fourteen patients (15 hands) with spastic thumb-in-palm deformities were treated with a modified technique of extensor pollicis longus tendon rerouting. Twelve patients obtained satisfactory correction of their deformities. Although functional improvement was not always anticipated, it was achieved to some degree in 12 patients. Extensor pollicis longus tendon rerouting can provide satisfactory correction of severe thumb-in-palm deformity especially when combined with other procedures such as metacarpophalangeal joint arthrodesis and thumb intrinsic muscle release. The modified rerouting technique can be done with a single incision and allows easy adjustment of tension.

Adolescent↗
PubMed1996

Pharmacologic regulation of Dupuytren's fibroblast contraction in vitro.

Dupuytren's disease is associated with contraction of specialized fibroblasts present in the diseased palmar fascia. Pharmacologic agents were evaluated for their ability to promote or inhibit contraction of Dupuytren's fibroblasts in vitro using a collagen lattice contraction assay. In the first part of the study, lysophosphatidic acid (LPA), serotonin, angiotensin II, and prostaglandin F2 alpha were tested for their ability to promote Dupuytren's fibroblast contraction. Lysophosphatidic acid was found to significantly promote Dupuytren's fibroblast contraction as compared with controls. This response to LPA is dose dependent, with a half-maximal response of 0.07 microM. Angiotensin II, serotonin, and prostaglandin F2 alpha at 1 mM, induced a significant amount of contraction as compared to controls, but the amount of contraction was at least six times less than that observed for LPA. In the second part of the study, prostaglandins E1 and E2 or the calcium blockers nifedipine and verapamil were tested for their ability to inhibit LPA-promoted contraction. It was found that both types of inhibitors partially block LPA-promoted contraction of Dupuytren's fibroblasts. The effect of the various pharmacologic agents on normal palmar fibroblasts was not evaluated. The focus of this study was to examine the regulation of contraction of Dupuytren's fibroblasts. This study demonstrates that LPA is a potent agonist of Dupuytren's fibroblast contraction and that this contraction can be inhibited by specific pharmacologic agents. These findings provide a rational basis for investigating further the clinical use of the calcium channel blockers nifedipine or verapamil and prostaglandins E1 and E2 to control Dupuytren's disease and possibly other fibrotic conditions.

Alprostadil↗
PubMed1996

Recurrent dislocation of the pisiform bone.

A 17-year-old man had chronic pain and recurrent radial dislocation of the pisiform bone following a fall on his outstretched arm. The bone was excised, along with a 3 x 4-mm osteocartilaginous fragment from the distal triquetrum. Pisotriquetral joint instability should be considered in the differential diagnosis of palmar-ulnar wrist pain.

Adolescent↗
PubMed1996

Fractures and nonunions of the scaphoid.

Fractures of the scaphoid are the most common of all fractures of the carpal bones. Scaphoid collapse and angular deformity may develop after fractures. Scaphoid nonunion often complicates scaphoid fractures especially if the diagnosis is missed initially, and adequate timely treatment is not provided. Displaced unstable fractures also have a tendency to develop nonunion. The tenuous vascular anatomy of the scaphoid, the inherent biomechanical instability of scaphoid fractures, and the difficulty of radiographic diagnosis are the culprits of nonunion. Established scaphoid nonunion is a challenging and difficult problem to treat and more so is the treatment of failed nonunion after grafting. New methods of diagnosis and treatment of scaphoid injuries are constantly evolving. One common method of treating scaphoid nonunion with angular deformity is length restoration using a wedge bone graft and Herbert screw fixation through a palmar approach. Early diagnosis and attention to details of surgical technique are necessary for successful treatment outcome. The purpose of this report is to review the basic science, diagnosis, and treatment of scaphoid fractures and nonunions.

Adolescent↗
PubMed1995

Anterior submuscular transposition of the ulnar nerve for cubital tunnel syndrome.

48 patients with 50 involved limbs were retrospectively analyzed to determine factors influencing the outcome of surgical treatment for cubital tunnel syndrome. All patients were treated by anterior submuscular transposition of the ulnar nerve with Z-lengthening of the flexor-pronator origin. There were 24 men and 24 women with an average age of 42 years +/- 16.4 years (range, 5-75 years). The average follow-up time was 58 months (range, 12-156 months). A grading system was used pre- and post-operatively based on the severity of subjective complaints and objective findings. 92% of the patients were satisfied, or satisfied with some reservations, and only 8% were dissatisfied. All patients had either fair or poor pre-operative grades. 84% had excellent or good post-operative grades and only 16% had fair grades. There were no recurrences or poor post-operative grades in our series. Workers' compensation status had no statistically significant adverse effect on post-operative patient satisfaction or post-operative grade. Anterior submuscular transposition of the ulnar nerve in this series provided satisfactory subjective outcome, relief of symptoms and adequate decompression of the ulnar nerve at the elbow.

Activities of Daily Living↗
PubMed1995

Ligamentous and tendinous support of the pisiform, anatomic and biomechanical study.

Twenty-five formalin preserved cadaveric wrists were dissected and the relationship of the piso-triquetral joint and its surrounding soft tissue structures were defined. An additional 4 fresh frozen wrists were examined in longitudinal and transverse sections. These anatomical studies showed the extensor retinaculum to have a complex insertion into the pisiform, flexor carpi ulnaris, fifth metacarpal, piso-metacarpal ligament, and the abductor digit minimi muscle. A capsulo-ligamentous structure on the medial aspect of the piso-triquetral joint was also identified. Bio-mechanical testing was performed on 12 fresh cadaver wrists and the results were compared to the anatomical findings to determine the contribution of surrounding soft tissue structures to piso-triquetral joint stability. Mechanical testing showed the soft tissues around the piso-triquetral joint to be strongest proximally and distally and weakest medially. Transection of the transverse carpal ligament resulted in increased lateral motion of the pisiform, but there was no significant decrease in stiffness. This study provides insight into the etiology of piso-triquetral joint instability and dysfunction.

Biomechanical Phenomena↗
PubMed1995

Correlation of alpha-smooth muscle actin expression and contraction in Dupuytren's disease fibroblasts.

We studied 11 nodules from patients with Dupuytren's contracture to determine whether alpha-smooth muscle actin expression in Dupuytren's fibroblasts is related to the generation of contractile force. Tissue was placed into explant culture and fibroblast strains were obtained. The mean percent of cultured Dupuytren's fibroblasts expressing alpha-smooth muscle actin, as determined by immunofluorescence, was 14 +/- 8 and ranged from 1% to 26%. The ability of Dupuytren's fibroblasts to generate contractile force was determined by using a previously described collagen lattice contraction assay. We observed a significant positive correlation between the expression of alpha-smooth muscle actin and the generation of contractile force in cell strains of Dupuytren's fibroblasts. In addition, six fibroblast strains from palmar fascia of individuals undergoing carpal tunnel release were examined. In six strains of palmar fibroblasts the mean percent of cells expressing alpha-smooth muscle actin was 5 +/- 3 and ranged from 1% to 9%. Six Dupuytren's fibroblast strains, in which more than 15% of the cells expressed alpha-smooth muscle actin, were significantly more contractile than the palmar fibroblasts. These results suggest that Dupuytren's fibroblasts can acquire smooth muscle characteristics and that the acquisition of a smooth muscle-like phenotype correlates with increased contractility.

Actins↗
PubMed1995

Vasoactive intestinal peptide and nerve growth factor effects on nerve regeneration.

Sixty rat sciatic nerves were used to study the effects of vasoactive intestinal peptide (VIP) and nerve growth factor (NGF) on nerve regeneration. They were divided into three groups. Groups 1 and 2 were treated with VIP and NGF, respectively, after dividing the nerves without repair and placing them in silastic chambers. Group 3 served a control. The rate and quality of nerve regeneration were compared among the groups using caliper measurements and histologic evaluation. Both VIP and NGF groups showed an enhanced rate of regeneration at three weeks as compared to controls (p < 0.05). The quality of nerve regeneration histologically and by axonal counting was not significantly different among the three groups, except for the presence of less vascularity in the VIP as compared with the NGF group. In addition to NGF, VIP appears to increase the rate of nerve regeneration as compared to controls.

Animals↗
PubMed1995

Ligamentous and tendinous support of the pisiform: anatomic and biomechanical study.

Twenty-five formalin-preserved cadaveric wrists were dissected and the relationship of the pisotriquetral joint (PTJ) and its surrounding soft tissue structures were defined. An additional 4 fresh frozen wrists were examined in longitudinal and transverse sections. These anatomical studies showed the extensor retinaculum to have a complex insertion into the pisiform, flexor carpi ulnaris, fifth metacarpal, pisometacarpal ligament, and the abductor digiti minimi muscle. A capsuloligamentous structure on the medial aspect of the pisotriquetral joint was also identified. Biomechanical testing was performed on 12 fresh cadaver wrists and the results were compared to the anatomical findings to determine the contribution of surrounding soft tissue structures to pisotriquetral joint stability. Mechanical testing showed the soft tissues around the pisotriquetral joint to be strongest proximally and distally and weakest medially. Transection of the transverse carpal ligament resulted in increased lateral motion of the pisiform, but there was no significant decrease in stiffness. This study provides insight into the etiology of pisotriquetral joint instability and dysfunction.

Biomechanical Phenomena↗
PubMed1995

Scaphoid fractures and nonunions.

Fractures of the scaphoid are the most common of all fractures of the carpal bones. Scaphoid collapse and angular deformity may develop after fractures. The tenuous vascular anatomy of the scaphoid, the inherent biomechanical instability of scaphoid fractures, and the difficulty of radiographic diagnosis are the culprits of nonunion. The treatment of established scaphoid nonunion is difficult, and more so is the treatment of failed nonunion after grafting. One common method for treating scaphoid nonunion with angular deformity is length restoration using a wedge bone graft and Herbert screw fixation through a palmar approach. Attention to details of surgical technique are necessary for successful treatment outcome.

Adolescent↗
PubMed1994

Generation of contractile force by cultured Dupuytren's disease and normal palmar fibroblasts.

Contractile fibroblasts are believed to be responsible for palmar fascia contracture in Dupuytren's Disease. An in vitro collagen lattice model was used to examine the contractile properties of Dupuytren's fibroblasts from 10 patients undergoing partial fasciectomy, and palmar fascia fibroblasts from 6 patients undergoing carpel tunnel release. Dupuytren's and palmar fascia fibroblasts cultured within a stabilized collagen lattice acquired morphological characteristics similar to those of 'myofibroblasts' in Dupuytren's diseased fascia. Both types of fibroblasts generated contractile forces that resulted in rapid collagen lattice contraction after release of the lattice from points of stabilization. Generation of contractile force by the fibroblasts was inhibited by disruption of the actin cytoskeleton, lack of cells, or serum removal. Afferent neuropeptides (substance P, galanin and neurokinin A) did not promote lattice contraction. These results demonstrate that normal palmar fascia fibroblasts can modulate into Dupuytren's-like fibroblasts and that cultured fibroblasts, from either Dupuytren's diseased or normal palmar fascia, can generate contractile forces that are transmitted to extracellular matrix. In addition, fibroblast contraction is an actin based process which requires specific factor(s) present in serum. It is suggested that in Dupuytren's disease extracellular cues trigger the modulation of fibroblasts to Dupuytren's fibroblasts and the promotion of contractile forces responsible for palmar fascia contrature.

Actins↗