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Biomedical subjects

M H Gonzalez

Publications and source records attributed to M H Gonzalez.

At least 19 recordsLinked to original sources
PubMed2001

Functional and structural effects of GM-1 ganglioside treatment on peripheral nerve grafting in the rat.

Peripheral nerve regeneration after traumatic injury and standard repair with a nerve autograft is usually incomplete. This study tested the influence of graft vascularity and pharmacological intervention with GM-1 ganglioside on nerve regeneration in a rat sciatic nerve model. Controls included an unoperated contralateral side and sham-operated groups either with or without the GM-1. During the 5 months of recovery, locomotion was tested by the sciatic function index (SFI). At killing, anesthetized animals were prepared for nerve conduction velocity (NCV) studies, followed by the wet weight of the gastrocnemius muscle (expression of atrophy), toe-chewing (expression of lesion severity and sensory loss), and histological examination of the nerve segments. The SFI showed a slight but significant recovery for both the vascular and avascular groups (34% at 20 weeks), but when GM-1 ganglioside treatment was included, the SFI was poor throughout (20-33%). The average NCV of the graft groups without GM-1 was 46% to 57% of the normal nerve (52.7 m/s), whereas for the groups treated with GM-1, it was 63% to 64% of normal; treatment of the non-vascular graft group significantly improved recovery. A uniformly poor recovery from muscle atrophy was seen for all nerve graft groups (62-67%) compared with normal controls. The mean number of toes per foot chewed was 1.9 and 2.4 in graft groups without GM-1 treatment and 0.9 and 1.3 in graft groups treated with GM-1. This treatment significantly reduced both the extent and the number of animals exhibiting autotomy. The qualitative microscopic appearance of the distal nerve segment in all surgical groups was similar. We conclude that the systemic addition of GM-1 ganglioside enhances only some aspects of regeneration in grafted nerves, possibly with a preferential effect on sensory nerve regeneration and functional recovery.

Animals↗
PubMed2001

Geometric analysis of potential error in using femoral intramedullary guides in total knee arthroplasty.

Proper component orientation is necessary for the long-term success of a total knee arthroplasty. Femoral component placement has used jigging systems that are based on intramedullary and extramedullary guides. The intramedullary system has been shown to foster more accurate and reproducible placement of the femoral component. This study analyzed and quantified the potential error of the intramedullary guide system. Geometric data of the human femur were obtained from radiographs of 45 cadaver femora in the anteroposterior and lateral views. The correct entry point of the intramedullary rod in the distal femur is the midaxial line of the femoral canal on anteroposterior and lateral radiographs. The position of this point in relation to the mediolateral and anteroposterior dimensions of the distal femur was calculated as a ratio. The average calculated ratios were anteroposterior, 0.53 offset medially; lateral, 0.32 offset anterior. Mathematical models were constructed to quantify the potential varus valgus and flexion extension error of the guide rods. Variables investigated were entry point location, guide rod diameter, guide rod length, and rotation. The surgeon must be cognizant of these potential sources of error to maximize the accuracy of the femoral intramedullary jigging system.

Arthroplasty, Replacement, Knee↗
PubMed2001

The ulnar nerve at the elbow and its local branching: an anatomic study.

Thirty nine cadaver elbows were dissected and the branching of the ulnar nerve, as well as the cubital tunnel and adjacent potential sites of nerve compression were studied. An arcade of Struthers was present in 26 specimens and Osborne's ligament was present in all specimens. A discrete flexor pronator aponeurosis overlying the ulnar nerve was present in 17 specimens. An average of one (range, 0-3) capsular nerve branches were noted. These originated an average 7 mm proximal (range, 45 mm proximal to 24 mm distal) to the medial epicondyle. An average of three (range, 1-6) motor branches to the flexor carpi ulnaris muscle were noted, and one of these originated proximal to the medial epicondyle in two specimens. Significant variation was noted in the capsular and motor branching of the ulnar nerve. Care must be taken to identify the motor branches of the ulnar nerve when performing a transposition.

Dissection↗
PubMed2001

Steroid injection and splinting in the treatment of carpal tunnel syndrome.

Thirty-five hands in 30 consecutive patients with carpal tunnel syndrome confirmed by nerve conduction velocity, 2-point discrimination <6 mm, and no thenar weakness were injected with corticosteroid. Patients underwent follow-up at 3, 6, 12, and 18 months or until symptoms recurred. Symptomatic relief obtained at 3 months was 34% and only 11% at 12 and 18 months. No correlation with clinical response and age, duration of symptoms, or sex was noted.

Adult↗
PubMed2001

Gouty tenosynovitis of the wrist.

A 56-year-old man presented with a mass of the right wrist limiting excursion of the digits. Operative exploration demonstrated gouty infiltration of the flexor tendons. The tendons were debrided of the urate crystalline material and the motion of the digits returned, preserving all tendon function. The patient later returned with symptoms of carpal tunnel in the contralateral wrist. Exploration of the carpal tunnel revealed similar infiltration of the flexor tendons. The tendons were debrided and the carpal tunnel syndrome resolved.

Follow-Up Studies↗
PubMed1999

Upper extremity infections in patients with diabetes mellitus.

Forty-five consecutive diabetic patients with 46 upper extremity infections who underwent surgical debridement were retrospectively reviewed. The infections involved the skin or subcutaneous tissue in 19 patients and the fascia, tendon, muscle, or bone in 27. Twenty-three infections (50%) required a single operation and 23 required more than 1. Eighteen infections (39%) required an amputation and there were 3 deaths directly related to an infection. Six of 7 infections in which anaerobic organisms were cultured culminated in amputation. Four patients were diagnosed with necrotizing fasciitis. Twenty-one cultures (46%) were polymicrobial. An increased rate of amputation was associated with deep infections below the subcutaneous tissue, renal failure, and infections with gram-negative, anaerobic, or polymicrobial cultures. An increased rate of repeat surgery and a prolonged hospitalization were associated with deep infection and polymicrobial infections.

Amputation, Surgical↗
PubMed1999

Femoral shaft fracture after hip arthroplasty: a system for classification and treatment.

Twenty-one consecutive cases of femoral shaft fracture after hip arthroplasty treated at the University of Illinois affiliated hospitals were reviewed. Adequate follow-up and radiographs were available for 19 patients. The length of follow-up after fracture ranged from 2 to 13 years, with a mean of 3.1 years. The time from index procedure to fracture averaged 2.6 years, with a range of 10 days to 11 years. The primary femoral stem was cemented in 11 hips and cementless in 8 hips. Six patients were treated nonoperatively and 13 operatively. Three had fracture fixation with retention of a well-fixed prosthesis and 10 had prosthetic revision. Cortical allograft was used in 5 cases. Sixteen of the 19 patients returned to their prefracture level of function and ambulation. The factors important to treatment are fracture stability, implant stability, and adequacy of bone stock. A classification system based on these factors and recommendations for treatment are proposed.

Adult↗
PubMed1999

Open fractures of the hand.

Open fractures of the hand are a challenging clinical problem for the orthopedic surgeon. The fracture is often comminuted with substance loss. Additionally, the fracture site can be contaminated by foreign material. The soft tissue envelope is violated with a variable degree of tissue devitalized. The wound contamination and tissue destruction lead to a rate of infection that can be much higher than that for a closed fracture. Initially, management of a significant soft tissue injury must take precedence over definitive fracture fixation. Proper staging of debridement, wound closure, and definitive fixation is paramount in minimizing infection while obtaining fracture union.

Algorithms↗
PubMed1998

Dupuytren's disease in African-Americans.

Seventeen African-American patients were operated on for Dupuytren's contracture over a 14-year period. Six-month minimum follow-up was available for 16 patients. The initial deformity, and results of surgical release of Dupuytren's contracture in this population was similar to that described in North Europeans.

Adult↗
PubMed1998

The chiasma of the flexor digitorum superficialis tendon.

Forty cadaver hands (160 fingers) were dissected to study the morphology and variations of the chiasma of the flexor digitorum superficialis tendon. Ten types of chiasma were noted. One chiasma did not fit into any of the patterns. The long and ring fingers had a very similar distribution of types of chiasma but the index and small both had different patterns. The length of chiasma showed a marked variability which appeared to be independent of phalangeal length.

Finger Joint↗
PubMed1998

Low-velocity gunshot wounds of the proximal phalanx: treatment by early stable fixation.

Twenty-eight proximal phalangeal fractures secondary to low-velocity gunshot wounds in 27 patients treated by stable fixation were retrospectively reviewed. Definitive fixation was performed within 1 week of injury. Fractures were stabilized with either a plate, intramedullary spacer, or a combination of both. When necessary, supplemental fixation was achieved with cerclage wires or interfragmentary screws. Twenty fractures with bone loss or comminution were primarily supplemented with iliac crest bone graft. After surgery, the fingers were splinted in 90 degrees of metacarpophalangeal (MP) flexion. An aggressive supervised therapy program was initiated within 24 hours of surgery. The average length of follow-up care was 9 months (range, 3-29 months). Primary union was achieved in all fractures. The average range of motion was 83 degrees for the MP joint and 66 degrees for the proximal interphalangeal joint. The average total active motion (TAM) for the involved digits was 200 degrees (range, 65 degrees-250 degrees). Fractures without intra-articular extension had a significantly better average TAM (213 degrees) than did those with intra-articular extension (169 degrees; p = .05). Primary bone grafting did not adversely effect the final TAM. There were no infections. Early stable fracture fixation of these injuries achieved union, alignment, and early rehabilitation with no appreciable increase in morbidity.

Adult↗
PubMed1998

Upper extremity infections in patients with the human immunodeficiency virus.

Twenty-eight patients with upper extremity infections and positive for the human immunodeficiency virus (HIV) were identified. The risk factor for HIV infection was intravenous drug injection in 24 patients, homosexual contact in 3, and heterosexual contact in 1. Eight of the patients had the acquired immunodeficiency syndrome. Two of the cases were prolonged herpetic infections of more than 6 months' duration that did not respond to oral acyclovir. The other 26 cases were bacterial in origin. Twenty-six of 28 cases responded to therapy with resolution of the infection. One patient refused surgical treatment and one died of systemic illness before resolution of the hand infection.

AIDS-Related Opportunistic Infections↗
PubMed1998

Necrotizing fasciitis and gangrene of the upper extremity.

Necrotizing fasciitis is a severe, fulminant infection most commonly encountered in patients with diabetes mellitus, alcohol abuse, and intravenous drug abuse. The infection can spread-unrecognized along fascial planes beneath seemingly normal skin. The relatively benign appearance of the extremity is misleading and often results in delay in diagnosis and increased morbidity or death. Immediate aggressive surgical debridement through extensile incisions in combination with antibiotic therapy is necessary for control of these limb- and life-threatening, soft-tissue infections. Gas gangrene, or clostridial myonecrosis, is encountered commonly in those extremity wounds that involve devitalized or necrotic soft tissues. Clostridial microorganisms are anaerobes that produce local and systemic toxins. Delay in treatment can lead to hemolysis, renal failure, and death. Treatment consists of immediate wound debridement, intravenous antibiotics, and hyperbaric oxygen therapy. Diabetic gangrene typically occurs in those diabetic patients with severe peripheral vascular or renal disease. The infections are usually polymicrobial. Treatment involves broad-spectrum antibiotics and multiple surgical debridements or amputation.

Adult↗
PubMed1997

Laparoscopic hernioplasty: why does it work?

BACKGROUND: To understand how laparoscopic hernioplasty prevents early recurrence of hernia, we reviewed our first 1,000 patients. We analyzed the patients by age, sex, and hernia type and by whether their hernia was primary or recurrent. METHODS: The 1,000 patients had 1,336 hernias repaired by the transabdominal preperitoneal or the totally extraperitoneal approach. One thousand one hundred seventy-three hernias were primary and 163 were recurrent. The type of hernia found varied with the patient's age (p < 0.001), and with whether the hernia was primary or recurrent (p < 0.001); 14% of primary and 27% of recurrent hernias were complex, a surprisingly high incidence compared to historical controls. RESULTS: With a median follow-up of 2 years, five hernias have recurred and all were due to technical errors. CONCLUSIONS: The laparoscopic repair's success may partially be due to its unique ability to diagnose previously overlooked complex elements. The defects are repaired without creating tension and the groin is reinforced with mesh, eliminating inherent weakness.

Adolescent↗
PubMed1997

Variations of the flexor digitorum superficialis tendon of the little finger.

Seventy cadaveric hands were dissected to study variations of the flexor digitorum superficialis tendon (FDS) to the little finger. Anatomical variations were present in 13% of hands and 10% of the hands showed an anatomical variation that would preclude independent FDS function in the little finger. The distance of the decussation from the metacarpophalangeal joint was measured. A ratio of this distance to proximal phalangeal length was calculated. The ratio indicated that decussation position was independent of phalangeal size.

Cadaver↗