Activity of commercial enzymes on settlement and adhesion of cypris larvae of the barnacle Balanus amphitrite, spores of the green alga Ulva linza, and the diatom Navicula perminuta

Fouling species produce adhesive polymers during the settlement, adhesion and colonization of new surfaces in the marine environment. The present paper tests the hypothesis that enzymes of the appropriate specificity may prevent biofouling by hydrolysing these adhesive polymers. Seventeen commercially available enzyme preparations designed originally for bulk use in a range of end-use applications were tested for their effects on the settlement and/or adhesion of three major fouling species, viz. the green alga Ulva linza, the diatom Navicula perminuta and the barnacle Balanus amphitrite. The serine-proteases were found to have the broadest antifouling potential reducing the adhesion strength of spores and sporelings of U. linza, cells of N. perminuta and inhibiting settlement of cypris larvae of B. amphitrite. Mode-of-action studies on the serine-protease, Alcalase, indicated that this enzyme reduced adhesion of U. linza in a concentration-dependent manner, that spores of the species could recover their adhesive strength if the enzyme was removed and that the adhesive of U. linza and juvenile cement of B. amphitrite became progressively less sensitive to hydrolysis as they cured.

Novel mode of resistance to Fusarium infection by a mild dose pre-exposure of cadmium in wheat

Exposure of healthy wheat seeds (Triticum aestivum var Sonalika) to mild dose of cadmium (Cd(2+)) given as 50 microM CdCl(2) for 48 h and then washed off Cd(2+) offered resistance to the subsequent infection by Fusarium oxysporum inoculum. Seven days old seedlings having two primary leaves were aseptically inoculated with fungus, F. oxysporum (1 x 10(6)) spores. The seedlings pre-exposed to low level of Cd(2+) survived the Fusarium infection, while plantlets without Cd(2+) stress wilted and then perished due to Fusarium infection. The stress associated proteins induced by Cd(2+) (50 microM), F. oxysporum and by the co-stress (50 microM Cd(2+) and then with F. oxysporum) treatments were observed to be of same molecular weight (51 kDa). Antibody was raised against the purified Cd(2+)-stress associated protein (CSAP). Immuno-gold labeling of wheat seedling root tissue showed the presence of this CSAP in Cd(2+) pre-exposed and in co-stressed tissues and to be located predominantly on the inner linings of the cell membranes. We also observed that the anti-CSAP-antibody also labeled the root tissue of only Fusarium inoculated seedlings and the gold labeling was intensely located on the membrane. This cross-reaction of anti-CSAP suggests that Fusarium-induced stress protein (FISP) possibly has close homology to CSAP. We thus show for the first time the over expression of a high molecular mass protein by mild dose of Cd(2+) pre-exposure to wheat seeds which subsequently provided protection against Fusarium infection. This mode of resistance developed by an abiotic stress-causing agent against pathogen infection is novel.

Functional outcome of patients with salvageable limbs with grades III-B and III-C open fractures of the tibia

Numerous reports list predictive criteria to determine whether Gustilio-type tibial III-B and III-C fractures of the tibia are salvageable. What is lacking are long-term reports of comprehensive functional outcome of these severe injuries. We evaluated the functional outcome of patients with our own seven-scale score. Fifty-four patients with 57 types III-B (n = 41) and III-C (n = 16) open tibial fractures sustained between 1980 and 1989 were recalled for evaluation. There were 45 men and 9 women (average age, 28.4 years; range, 4-68 years). Follow-up periods averaged 48.2 months (range, 12-116 months). Salvage rate for the III-B fractures was 75% (n = 31) and for the III-C fractures 37% (n = 6). We conclude that the functional score is a simple and complete method for assessing the functional outcome of patients undergoing limb salvage procedures.

Supracondylar femur fractures treated percutaneously

One hundred twenty-five supracondylar fractures in 118 patients treated with the Green-Seligson-Henry supracondylar intramedullary nail were evaluated. One hundred four patients (111 fractures) were followed up to fracture union. The percutaneous technique was compared with open reduction and internal fixation using the same device. The mean operative time was greater for the open reduction technique when compared with the percutaneous technique (176 minutes versus 76.6 minutes, respectively), as was the mean estimated blood loss (229 cc versus 96.2 cc). The incidence of delayed union was approximately the same for patients who were treated with both techniques. However, the nonunion rate was significantly higher in the patients treated with open reduction and internal fixation than the patients treated with the percutaneous technique (5.6% versus 2.6%). Twenty-nine (39%) patients who were treated with open reduction and internal fixation required bone grafting versus only three (7%) patients who were treated with the percutaneous technique. Additionally, the percutaneous technique did not produce a higher incidence of malalignment and resulted in a greater postoperative range of motion than the open technique. The current study shows that percutaneous treatment of supracondylar femur fractures is possible and can decrease operative times, blood loss, the need for bone grafting, increase rates of union, and improve functional outcomes.

Role of genotypic analysis of the thymidine kinase gene of herpes simplex virus for determination of neurovirulence and resistance to acyclovir

Mutations in the thymidine kinase (TK) gene of herpes simplex virus (HSV) have been associated with resistance to acyclovir (ACY) and possible recognition of neurotropic strains. We sequenced a 335-bp segment of the TK gene to determine the frequency of mutations in HSV strains recovered from dermal, genital, and cerebrospinal fluid (CSF) specimens (n = 200; 102 HSV type 1 [HSV-1] 98 HSV-2 strains). Four polymorphic sites were detected in HSV-1 strains; C513T, A528G, C575T, and C672T. Among the polymorphisms, only C575T resulted in a change of amino acid sequence (residue 192, Ala-->Val). For HSV-2 strains, only one polymorphism (G420T) which resulted in an amino acid substitution (residue 139, Leu-->Phe) was detected. Phenotypic determination of resistance to ACY by a plaque reduction assay of 48 HSV isolates was not correlated with the sequence results of 11 strains in that 7 of these with genotypic polymorphisms were susceptible to the drug in vitro. In addition, of 32 ACY-resistant HSV strains, 28 (87.5%) had no polymorphisms detected in the 335-bp amplicon of the TK gene. There was no statistical difference in the frequency of polymorphisms according to the source of the specimens. We conclude that the detection of nucleic acid polymorphisms in a previously implicated 335-bp segment of the TK gene cannot be interpreted as indicative of either ACY resistance or neurotropism of HSV strains from dermal, genital, and CSF sources.

[Treatment concept and results of grade 3 open fractures with arterial injuries requiring reconstruction]

Ninety-one open fractures associated with arterial injury requiring vascular repair (type IIIC injuries) were treated at the University of Louisville between May 1983 and January 1994. Involved anatomical areas were the humerus (6x), the forearm (11x), the femur (16x), the tibia (36x), the ankle (11x) and the foot (11x). Fracture management consisted of meticulous radical debridement, copious wound irrigation, fasciotomy and fracture stabilization. Additionally, 49 wounds (53.8%) were treated with the supplemental local use of antibiotics (tobramycin-PMMA-beads). Thirty-four patients underwent primary amputation whereas 57 repairs of the injured vessels were performed. There were 7 secondary amputations due to infection or poor revascularization resulting in an overall amputation rate of 45.1%. The wound infection rate was 12.1% (11/91) and the rate for osteomyelitis was 3.3% (3/91). The local use of the antibiotic beads was of significant benefit to lower infectious complications. Primary coverage of the soft tissue defect with free tissue transfer was associated with a high infection rate (2/3) and is not recommended for this type of injury. Temporary wound coverage with the "antibiotic bead pouch" technique until wound closure can be obtained in a sterile and viable environment leads to more satisfying results.

Management of supracondylar fractures proximal to total knee arthroplasty with the GSH supracondylar nail

The management of a supracondylar fracture above a total knee arthroplasty requires a cautious surgical approach. Currently, the standard method of plate/screw internal fixation of this type of fracture has yielded only fair results. A new technique of retrograde intramedullary nailing through the femoral component using the GSH supracondylar nail is described in this report. A review of four series in which more than 50 patients were treated using the GSH nail indicates a significant difference in bone grafting (10% versus 75%), delayed union (7.2% versus 50%), nonunion (1.9% versus 10%), and surgical revision (0 versus 10%) compared to plate/screw fixation of similar fractures. The findings in this review indicate that the GSH supracondylar nail provides excellent biomechanical stability in these complex fractures, resulting in minimal complications and allowing early return of the patient to functional activities.

Local antibacterial therapy for the management of orthopaedic infections. Pharmacokinetic considerations

Bone infection has long been a formidable foe of orthopaedic surgeons. The standard method of treating osteomyelitis generally consists of irrigation and debridement supplemented by pre- and postoperative antibiotics and intraoperative antimicrobial solutions. In the 1970s, Buchholz introduced the concept of local antibacterial therapy in the form of antibiotic impregnated bone cement to treated infected arthroplasties. From this, antibiotic impregnated beads were developed to treat local infections of bone and soft tissue. The advantage of these beads compared with parenteral therapy is that they deliver a high concentration of antibacterial locally while avoiding high systemic concentrations, thus avoiding adverse effects that are often associated with parenteral antibacterial therapy. Additionally, methylmethacrylate bone cement does not significantly affect the immune response of the body. This makes the use of antibiotic-impregnated polymethylmethacrylate (PMMA) beads highly effective either as an alternative to, or in conjunction with, systemic antibiotic treatment of infected arthroplasties, and localised bone and soft tissue infection. This article explores the indications for the use of local therapy as well as any advantages or disadvantages it may have over systemic antibacterial treatment. Additionally, there are important pharmacokinetic considerations for the optimal use of antibacterial agents in the treatment of osteomyelitis.

Tibial pilon fractures: a comparative clinical study of management techniques and results

Thirty-eight consecutive pilon fractures were reviewed retrospectively to compare the radiographic and clinical results with the original injuries based on three different treatment options: external fixation only, external fixation with limited internal fixation, and internal fixation only. Dates of injury were from February 1985 to February 1989. Treatment method was the surgeon's preference. The mean follow-up time was 28 months. Results were tabulated by clinical and radiographic scores. In general, simple fracture types had good results; complex ones did less well. In this study, fracture severity appeared to be the key variable in outcome.

Local antibiotic therapy for severe open fractures. A review of 1085 consecutive cases

We reviewed 1085 consecutive compound limb fractures treated in 914 patients at the University of Louisville over a nine-year period. Of these fractures, 240 (group 1) received only systemic antibiotic prophylaxis and 845 (group 2) were managed by the supplementary local use of aminoglycoside-polymethylmethacrylate (PMMA) beads. There were no significant differences in age, gender, fracture type, fracture location or follow-up between the two groups. All had copious wound irrigation, meticulous debridement and skeletal stabilisation, but wound management and the use of local antibiotic depended on the surgeon's individual preference and there was no randomisation. In group 1 there was an overall infection rate of 12% as against 3.7% in group 2 (p < 0.001). Both acute infection and local osteomyelitis showed a decreased incidence in group 2, but this was statistically significant only in Gustilo type-IIIB and type-IIIC fractures for acute infection, and only in type-II and type-IIIB fractures for chronic osteomyelitis. Our review suggests that the adjuvant use of local antibiotic-laden PMMA beads may reduce the incidence of infection in severe compound fractures.

Local antibiotic therapy for severe open fractures. A review of 1085 consecutive cases

We reviewed 1085 consecutive compound limb fractures treated in 914 patients at the University of Louisville over a nine-year period. Of these fractures, 240 (group 1) received only systemic antibiotic prophylaxis and 845 (group 2) were managed by the supplementary local use of aminoglycoside-polymethylmethacrylate (PMMA) beads. There were no significant differences in age, gender, fracture type, fracture location or follow-up between the two groups. All had copious wound irrigation, meticulous debridement and skeletal stabilisation, but wound management and the use of local antibiotic depended on the surgeon's individual preference and there was no randomisation. In group 1 there was an overall infection rate of 12% as against 3.7% in group 2 (p < 0.001). Both acute infection and local osteomyelitis showed a decreased incidence in group 2, but this was statistically significant only in Gustilo type-IIIB and type-IIIC fractures for acute infection, and only in type-II and type-IIIB fractures for chronic osteomyelitis. Our review suggests that the adjuvant use of local antibiotic-laden PMMA beads may reduce the incidence of infection in severe compound fractures.

The management of open fractures associated with arterial injury requiring vascular repair

Seventy-two open fractures associated with arterial injury requiring vascular repair (Gustilo type IIIC injuries) were treated at the University of Louisville from May 1983 and through 1992. The involved anatomic areas were the humerus (four), forearm (ten), femur (eight), tibia (31), ankle (ten), and foot (nine). Fracture management consisted of careful débridement, wound irrigation, fasciotomy, and fracture stabilization. Additionally, 40 wounds (55.6%) were treated with the supplemental use of local antibiotics (tobramycin-PMMA bead chains). Twenty-three patients (32.1%) underwent primary amputation, and 49 (67.99%) of the injured vessels were repaired. There were seven secondary amputations because of infection or poor revascularization, resulting in an overall amputation rate of 41.6%. The wound infection rate was 13.9% (10 of 72) and the rate for osteomyelitis was 4.2% (3 of 72). The local use of the antibiotic bead chains was of significant benefit in lowering infectious complications. Primary coverage of soft-tissue defects with free tissue transfer had an infection rate of 66%; temporary wound coverage with the "antibiotic bead pouch" technique until wound closure can be obtained in a sterile and viable environment appears to be a better option.

[Treatment of the ipsilateral femur shaft and femur neck fractures with the Russell-Taylor reconstruction nail]

Eleven ipsilateral neck and shaft fractures of the femur in 11 patients (4 females, 7 males) were treated between May 1987 and December 1990 at the Department of Orthopedic Surgery. University of Louisville, Trauma center level one. The mean age was 34.5 (16-60) years. All patients sustained their injuries from high energy trauma (8 traffic accidents, 3 falls). All neck fractures were closed and there were 8 closed and 3 open (grade I, grade II, grade IIIA = one each) shaft fractures. All fractures were operated on the fracture table and all were stabilized with the Russell-Taylor reconstruction nail. Thus, antegrade reamed nailing of the shaft fracture was followed by internal fixation of the neck fracture with 8.0 mm and 6.4 mm lag screws. Those were placed with a targeting device through the proximal locking holes of the nail. Then, the distal locking bolts were implanted by free hand technique. The mean follow-up was 36.2 (18-71) months. All fractures of the neck and shaft healed. There was no necrosis of the femoral head. No infection was observed. The mean healing time for the neck fractures was 13.4 weeks and 16.8 weeks for the shaft fractures. In one case autogenous cancellous bone grafting was performed in delayed healing of a shaft fracture. There were no varus or valgus malangulations. Five patients had a minor limited ROM of the hip joint, another 6 patients an average shortening of 1.3 cm of he involved leg. In one case a locking bolt had to be removed due to loosening.(ABSTRACT TRUNCATED AT 250 WORDS)

Removal of broken syndesmotic screws: a technical tip

A simple method of extracting broken distal tibial-fibular syndesmotic or cross-locking screws for intramedullary nails is illustrated. After extraction of the head portion of the broken screw, a blunt impactor is introduced through the vacant screw hole and abutted to the remaining portion of the screw tip. The screw can usually be impacted through the far cortex. A small incision should be made over the protruding portion, and the screw extracted with pliers.

Bracing of stable shaft fractures of the ulna

In the laboratory an ulnar osteotomy was performed in 10 cadaveric specimens, which included 5 distal-third junctions and 5 middle-third junctions. The interosseous membrane was left intact. Each specimen was rotated through full pronation and full supination. Displacement less than half shaft width was considered stable. The interosseous membrane was subsequently released 2 cm proximal and 2 cm distal to the osteotomy. Repeated pronation and supination range of motion documented gross displacement greater than half of the width of the shaft and was diagnosed as unstable. To evaluate this hypothesis, a clinical trial of 30 stable ulnar shaft fractures of the middle and distal thirds were treated with functional bracing between 1984 and 1990. A simple protocol was followed: A long arm cast was applied for approximately 5-7 days until the patient experienced only mild pain. At 5-7 days, a prefabricated forearm brace was fitted and the patient began physical therapy, advancing the upper extremity to full functional use. The bracing was continued until radiographic union had occurred. Twenty-nine clinical cases were evaluated to fracture union. The mean time to union was 7.3 weeks (range: 6-9 weeks). One delayed union was reported in the series. At 16 weeks surgical intervention was recommended and an open reduction and internal fixation with cancellous bone grafting was performed. Twenty-nine patients regained full range of motion, and one had limited supination/pronation due to a previous injury of the radial head. In conclusion, functional bracing of stable ulnar shaft fractures leads to a high incidence of fracture union and achieves good to excellent functional results.(ABSTRACT TRUNCATED AT 250 WORDS)

[Optimal timing of wound closure in severe open fractures with temporary coverage by skin substitute]

In a consecutive series of 1085 open fractures treated at the University of Louisville Level I Trauma Center from May 1983 to July 1992, 381 severe compound fractures in 335 patients were managed with the antibiotic bead pouch technique. There were 27 grade I (marked swelling, compartment syndrome), 115 grade II and 239 grade III open fractures (94 type IIIA, 114 type IIIB and 31 type IIIC). These fractures were managed with early administration of broad spectrum antibiotics, copious wound irrigation, serial debridements and external skeletal stabilization. Tobramycin-PMMA-beads were placed in the wound and porous plastic film (Opsite) covered the soft tissue defect. This dressing was changed every 48 to 72 hours until wound coverage/closure could be obtained. Infection rate either on an acute or chronic basis was 2.6% in grade II open fractures and 8.4% in grade III compound fractures. There was no infected wound or bone in the grade I category. Those fractures which did not develop an infection were closed at a mean time of 7.6 days; those which developed an infection were closed at a mean time of 17.9 days. The difference was statistically highly significant (p < 0.001). When severe open fractures are managed with the antibiotic bead pouch technique, wound closure should be obtained within one week to prevent infectious complications.

Timing of wound closure in severe compound fractures

In a consecutive series of 1085 open fractures treated from May 1983 to July 1992, 381 severe compound fractures in 335 patients were managed with the antibiotic bead pouch technique. There were 27 grade I (marked swelling, compartment syndrome), 115 grade II, and 239 grade III open fractures (94 type IIIA, 114 type IIIB, and 31 type IIIC). These fractures were managed with early administration of broad spectrum antibiotics, copious wound irrigation, serial debridements, and external skeletal stabilization. Tobramycin-PMMA beads were placed in the wound, and porous plastic film (Opsite, Smith and Nephew Medical, Limited, Hall, England) covered the soft tissue defect. This dressing was changed every 48 to 72 hours until wound coverage/closure could be obtained. Infection rate, either on an acute or chronic basis, was 2.6% in grade II open fractures and 8.4% in grade III compound fractures. There was no infected wound or bone in the grade I category. Those fractures that did not develop an infection were closed at a mean time of 7.6 days; those that developed an infection were closed at a mean time of 17.9 days. The difference was statistically significant (P < 0.001). When severe open fractures are managed with the antibiotic bead pouch technique, wound closure should be obtained within 1 week to prevent infectious complications.

Intramedullary supracondylar nailing of femoral fractures. A preliminary report of the GSH supracondylar nail

From 1987 through 1990, 34 acute supracondylar femoral fractures in 33 patients were treated with an interlocking closed-section intramedullary nail inserted retrograde into the femur through the intercondylar notch. Follow-up data of at least five months were available for 25 of these fractures. The patients suffered injuries more extensive than comparable patients reported in the literature. All fractures healed clinically and radiographically. The average arc motion at the most recent evaluation was 100 degrees. The average operative time was 156 minutes and the average estimated blood loss was 224 ml. Complications related to this treatment were successfully resolved. The genucephalic nail is a good treatment for supracondylar femoral fractures.

Comparison of the clinical efficacy and tolerance of gentamicin PMMA beads on surgical wire versus combined and systemic therapy for osteomyelitis

These data do not prove a statistical superiority of conventional antibiotics or Septopal in the treatment of chronic osteomyelitis. This result, however, is complicated by the biased data set represented by the combined treatment. The data do suggest that cost of treatment is considerably less in patients who are treated with local antibiotics (i.e., Septopal) alone. The rate of adverse experiences was directly related to the use of parenteral antibiotics, with higher rates of adverse experiences in the conventional and combined treatment groups. Furthermore, the Cierny-Mader Physiologic Class had the best correlation with outcome, suggesting that host factors are probably of critical importance in inducing remission of chronic osteomyelitis. This protocol was not designed to test the role of debridement in the treatment of osteomyelitis: it was assumed that debridement would be the same in both groups. It is the investigators' strong opinion, however, that adequacy of debridement was an important determinant in quiescence or recurrence in the study patients. Similarly, there was no strict control for adequacy of soft-tissue coverage provided by local or distant tissue transfer. Again, the investigators believe that adequacy, including viability and durability, of soft-tissue covering was an important determinant for the end result in these patients. Other covariants such as smoking, history, nutritional status, and other measures of general health will be added to this model when data are available. This analysis will allow definition of the appropriate clinical situations in which use of Septopal alone or combined with parenteral antibiotic is indicated.

The treatment of infected nonunions with gentamicin-polymethylmethacrylate antibiotic beads

Fifty-two patients enrolled in the Septopal study of infected nonunions were prospectively examined in a randomized, controlled, closed study. Patients were divided into two groups. Group 1 consisted of 24 patients treated with debridement and intravenous antibiotics for four weeks. Group 2 consisted of 28 patients treated with debridement, gentamicin-polymethylmethacrylate (Septopal) beads, and perioperative broad-spectrum parenteral antibiotics. Both groups were treated with similar methods for reconstruction of the nonunions. The demographics of the two groups were similar. The average patient age in Group 1 was 38.4 years, and in Group 2, 37.1 years. Group 1 included 21 men and three women and Group 2, 23 men and five women. The nonunions in both groups ranged from simple hypertrophic nonunions to atrophic unions to segmental defects. The end results were good in both groups. Twenty patients in Group 1 and 25 patients in Group 2 had their infections successfully arrested (83.3% and 89.3%, respectively). Nonunions were successfully healed in the two groups, with similar results (Group 1, 83.3%; Group 2, 85.7%). Infected nonunions responded equally well to either systemic treatment with long-term intravenous antibiotics or local treatment with gentamicin-polymethylmethacrylate beads.

The antibiotic bead pouch technique. The management of severe compound fractures

In a consecutive series of 704 compound fractures, 227 open fractures in 204 patients were managed with the antibiotic bead pouch technique. There were 16 Grade I compound fractures, 83 Grade II fractures, and 128 Grade III open fractures. The mean patient age was 35.25 years (range, 14-87). The Injury Severity Score (ISS) ranged from 9 to 57, with a mean of 15. Porous plastic film is placed over the soft-tissue defect to establish a "closed" bead-hematoma-fracture environment containing high local levels of antibiotic at the fracture site. All patients had serial wound debridements and parenteral systemic antibiotics (cefazolin, tobramycin, penicillin). Bead pouch changes ranged from one to seven per patient (mean, two). During these changes, 1248 cultures were taken, 78 (6.25%) of which were positive in 34 patients. Seventeen patients developed clinical signs consistent with an infection. The wound infection rate was 0% in Grade I open fractures, 1.2% in Grade II compound fractures, and 8.6% in Grade III open fractures. The osteomyelitis rate was 0% in Grade I compound fractures, 2.4% in Grade II open fractures, and 5.5% in Grade III compound fractures. Wound closure was obtained in 134 fractures with delayed primary closure of the skin, in 53 fractures with flap coverage, and in 23 fractures with split-thickness skin graft. Coverage was not completed in 17 wounds, at which time an amputation was performed or death occurred. Time of closure ranged from one to 32 days (mean, 7.1 days).(ABSTRACT TRUNCATED AT 250 WORDS)

A comparison of gentamicin-impregnated polymethylmethacrylate bead implantation to conventional parenteral antibiotic therapy in infected total hip and knee arthroplasty

A multicenter study of infected total knee and total hip arthroplasties was conducted from 1985 until 1990. Twenty-eight patients (22 total hip arthroplasties and six total knee arthroplasties) who had periprosthetic infections were treated according to a prospective, randomized protocol. After initial debridement for their infections, patients were randomized into one of the two following groups: Group I, debridement and the implantation of gentamicin-polymethylmethacrylate (PMMA) beads; and Group 2, debridement and conventional parenteral systemic antibiotic therapy. After initial treatment, the patients were then scheduled for a delayed reconstruction total joint arthroplasty. Of the 28 patients, 25 subsequently had delayed total arthroplasty, and if acrylic bone cement was used for fixation at the time of reimplantation, antibiotics were not added to the cement. The average follow-up period was three years (range, six months to 5.6 years). Infection recurred in two patients treated by debridement and the implantation of gentamicin-PMMA beads (15%) and in four patients treated with debridement and conventional systemic antibiotic therapy (30%). All recurrences occurred in patients who had infected total hip arthroplasties; none occurred in patients with total knee arthroplasties. The conditions that were common in patients with recurrent infection were (1) multiple previous surgeries, (2) host compromise and malnutrition, (3) extensive infection, and (4) inadequate debridement. The recurrence of infection was not statistically significantly more common in either treatment group. The outcome of treatment in patients with infected total joint arthroplasties using debridement, gentamicin-PMMA bead implantation,and a two-stage delayed reconstruction was similar to that of patients treated with debridement combined with conventional parenteral systemic arthroplasty and two-stage reconstruction.

Effects of serine protease inhibitor, TAME, on IL-1 beta in LPS-stimulated human monocytes: relationship between synthesis and release of a 33-kDa precursor and the 17-kDa biologically active species

LPS stimulation of human monocytes in vitro induced release of the 17-kDa mature IL-1 beta (mIL-1 beta) but did not result in release of precursor IL-1 beta (pIL-1 beta). In contrast, the presence of a serine protease inhibitor, N alpha-(p-toluene sulfonyl)-L-arginine methyl ester (TAME; 10 mM) for 6 or 18 h was associated with the LPS-stimulated release of the 33-kDa pIL-1 beta as well. These effects were initially discerned from observations that the fraction of the total IL-1 beta produced (as detected by ELISA) that was released from monocytes increased in the presence of TAME, and immunoblot assays confirmed that this fraction was predominantly 33-kDa IL-1 beta. A global decrease in monocyte protein synthesis was also observed after prolonged (18-h) exposure to TAME and was associated with a decrease in IL-1 beta synthesis, predominantly affecting 31-kDa pIL-1 beta, and a dose-dependent inhibition of TNF-alpha production. Parallel examination of lactate dehydrogenase (LDH) release indicated that pIL-1 beta release was unrelated to cell lysis. These results demonstrate that TAME-inhibitable serine proteases are probably involved in the production and eventual proteolysis of the 33-kDa pIL-1 beta in situ but are probably not mechanistically related to either maturation of the IL-1 beta molecule or signaling of IL-1 beta release. IL-1 beta release appears to be dependent on the amount of total IL-1 beta synthesized. Serine proteolysis may constitute a degradative pathway for excess precursor, which, if interfered with, could result in release of the higher-molecular-weight forms of IL-1 beta.

Long-term implantation of gentamicin-polymethylmethacrylate antibiotic beads

Fifty-two chronic osteomyelitis patients treated with gentamicin-polymethylmethacrylate (Septopal) antibiotic bead chains were observed retrospectively to explore the relationship between the duration of bead implantation and clinical results. Group A contained 35 asymptomatic patients who had elective bead removal based on protocol, surgeon's preference, and patient variables. Group B consisted of 17 patients who retained the antibiotic beads. The presence or absence of redness, abscess, drainage, pain, or swelling at the wound site was documented for clinical evaluation. Findings indicate that Septopal bead chain implants exhibit higher success (remission) rates with increasing length of duration without increasing the risk of complications.

The role of local antibiotic therapy in the management of compound fractures

Seven hundred four compound fractures (198 [28%] Grade I, 259 [37%] Grade II, and 247 [35%] Grade III) were treated during a seven-year period at the author's institution. One hundred fifty-seven open fractures (22%) (Group A) received systemic antibiotic prophylaxis only, whereas 547 compound fractures (78%) (Group B) were treated with local application of antibiotic beads (tobramycin) in addition to prophylaxis. Fracture grades, age, gender, fracture location, and length of follow-up period were not significantly different between the two groups. All fractures underwent timely irrigation, debridement, and skeletal stabilization. Forty-nine of 704 compound fractures (7%) developed an infection (acute wound infection or chronic osteomyelitis or both). Group A showed an infection rate of 17% (26/157); treatment in Group B resulted in 23 compound fracture infections (4.2%). The difference in the incidence of infection was statistically significant. Comparison of the infection rates in either wound infection or chronic osteomyelitis showed a trend toward decreased rates in Group B versus Group A throughout all fracture grades. However, by subdivision into the fracture grades, only the IIIB types had a statistically significant decrease of infection in Group B versus Group A; the wound infection rate was 39% (9/23) in Group A and 7.3% (7/96) in Group B. The rate of chronic osteomyelitis was 26% (6/23) in Group A and 6.3% (6/96) in Group B. Prophylactic use of antibiotic-laden PMMA beads in addition to systemic antibiotics was of benefit in preventing infectious complications in compound fractures, in particular in Type IIIB open fractures.

Antibiotic-leaching from polymethylmethacrylate beads

Aminoglycoside-impregnated polymethylmethacrylate beads, which are used to deliver antibiotic directly to infected sites in the musculoskeletal system, are available as a manufactured product or they can be mold-made by a pharmacy or hand-rolled by the orthopaedist in the operating suite. We investigated the leaching of antibiotic from each of these types of beads. Our hypothesis was that the elutions of antibiotic from the three types of beads are similar. Three study groups (hand-made, mold-made, and manufactured beads), each composed of four five-bead subsets, were formed so that twenty beads of each type were tested. Each bead was leached daily in a two-milliliter aliquot of normal saline solution throughout a sixty-day period, and the aminoglycoside concentration in twenty of these aliquots was determined. Analysis of variance showed no statistically significant differences when the antibiotic elutions within each subset, between the different subsets, and between the three groups were compared. The clinically important finding of this investigation is that the leaching characteristics of the three types of aminoglycoside-impregnated beads are equivalent when the beads have been fabricated out of comparable materials.

[Value of adjuvant local antibiotic administration in therapy of open fractures. A comparative analysis of 704 consecutive cases]

Seven hundred and four compound fractures--198 (28%) grade I, 259 (37%) grade II, 247 (35%) grade III (86 IIIA, 119 IIIB, 42 IIIC)--were treated in 590 patients between May 1983 and May 1989 at the University of Louisville. Of these fractures, 157 (22%, group 1) received systemic antibiotic prophylaxis only, whereas 547 (78%, group 2) were treated with additional local application of aminoglycoside beads (tobramycin). Comparison of factors (fracture grades, age, sex, fracture location, follow up) revealed no significant differences between the two groups. All fractures underwent timely irrigation, debridement and skeletal stabilization. In group 1, 52 wounds were primarily closed, 53 underwent delayed primary closure and 52 were left open. In group 2 283 wounds were primarily closed, 229 were managed with the bead pouch technique and 35 were adapted loosely (delayed closure). Forty-nine (6.96%) of the 704 compound fractures became infected (acute wound infection and/or chronic osteomyelitis). Group 1 showed an infection rate of 16.6% (26/157), group 2 a rate of 4.2% (23/547). The difference was statistically highly significant (P < 0.001). Comparison of the infection rates, whether on an acute or a chronic basis, showed that infection rates were lower in group 2 than in group 1 for all fracture grades. A statistically significant difference was established only for type IIIB fractures, where the wound infection rate was 39.1% (9/23) in group 1 and 7.3% (7/96) in group 2 (P < 0.001). The rate of chronic osteomyelitis was 26.1% (6/23) in group 1 and 6.3% (6/96) in group 2 (P < 0.025).(ABSTRACT TRUNCATED AT 250 WORDS)

The use of antibiotic-impregnated polymethylmethacrylate beads to prevent the evolution of localized infection

The effect of antibiotic bead chains on the evolution of infection cannot be studied entirely in man due to the ethical problems of obtaining valid controls. Therefore, a model of musculoskeletal injury was devised in rabbits by making a paraspinal wound, fracturing a spinous process, and contaminating the wound with 1 x 10(4) colony-forming units/ml of Staphylococcus aureus. These contaminated wounds were treated with tobramycin-containing polymethylmethacrylate (PMMA) beads. Control rabbits were either treated with PMMA beads that did not contain antibiotic, treated with IM tobramycin, or left untreated. At 5 days, six of eight animals treated with antibiotic-impregnated beads had no recoverable organisms. Six of eight rabbits receiving IM tobramycin had wound infections, and five of five in whom non-antibiotic-containing beads had been implanted had significant wound infections, with one of the five dying of sepsis on the 3rd day of the experiment. The clinical course of infected controls was the same as the course of those animals receiving IM antibiotics and the same as those in whom beads without antibiotics were implanted. That is, the rabbits had grossly infected wounds and the organisms recovered were of the same type as those implanted. This research shows a highly statistically significant effect of tobramycin-containing antibiotic beads in retarding the evolution of an experimental Staphylococcus infection in rabbits.

Bacterial adherence to plain and tobramycin-laden polymethylmethacrylate beads

Antibiotic-impregnated polymethylmethacrylate (PMMA) bead chains are in current clinical use for prophylaxis and management of osteomyelitis. The in vivo interaction between PMMA beads and an experimentally infected wound is examined. Two modes of bacterial adherence to plain PMMA beads are demonstrated. In this report, tobramycin-sensitive bacteria did not attach to tobramycin-laden beads. Therefore, implanted PMMA beads should contain an antibiotic to which the infecting bacteria is sensitive.

Domestic violence--the medical community's legal duty

During the last decade, domestic violence has been identified as one of the major causes of emergency room visits by women. As many as 30% of the women who are seen by emergency room physicians exhibit at least one or more symptoms of physical abuse. Unfortunately, the vast majority of these cases go unreported due to a lack of awareness on the part of physicians and other health care providers regarding the law, actual reporting procedures, and potential liability. This article addresses both the medical community's legal liability and the results of a January 1992 survey conducted by the Jefferson County Medical Society and University of Louisville. This survey evaluated local physicians' awareness of the statutory requirements imposed on the medical community when treating suspected victims of domestic violence. According to this survey of 215 physicians, only 29% were aware that Kentucky law requires physicians and other health care practitioners to report to the Cabinet for Human Resources any suspected abuse, neglect, or exploitation of an adult. Furthermore, the Jefferson County Medical Society survey reported that only 24% of the physicians polled had ever filed a domestic violence report on behalf of a patient. In an effort to compare the physicians' knowledge of other domestic violence issues, the physicians were also questioned regarding the issue of child abuse. Over 80% of physicians surveyed were aware of the Kentucky statute which requires a physician to report child abuse, and greater than 60% of those physicians surveyed had filed a complaint with a local or state agency. Domestic violence is now being publicly recognized as a social problem with far-reaching consequences.(ABSTRACT TRUNCATED AT 250 WORDS)

Management of supracondylar fractures of the femur with the GSH intramedullary nail: preliminary report

The GSH supracondylar nail is a closed section rigid intramedullary device that combines the biomechanical advantages of intramedullary fixation with the stability of rigid internal fixation for the management of supracondylar fractures of the femur. The use of this implant is indicated in the management of distal comminuted nonarticular fractures and fractures with intraarticular extension. Intramedullary fixation provides improved fracture stabilization in both elderly patients with osteoporotic metaphyseal bone and in younger patients with extensively comminuted fractures. The experience with the GSH supracondylar nail has shown that it provides better results than supracondylar plating for the stabilization of acute fractures or revision of failed internal fixation.

Treatment of compound fractures

Management of compound fractures remains a challenge to the surgeon. Methods to decrease patient morbidity include early fracture stabilization and sequential débridement. External fixation remains the standard; however, early internal fixation in low-grade injuries may be an acceptable option. Early soft tissue coverage is critical. The use of prophylactic parenteral antibiotics has decreased the incidence of acute infection and chronic osteomyelitis. Supplemental use of local antibiotic polymethyl methacrylate (PMMA) beads appears to further diminish the morbidity in high-grade open fractures.

Antibiotic-impregnated beads. Part II: Factors in antibiotic selection

Part I of this series discussed the advantages of implanted antibiotic-impregnated polymethylmethacrylate beads over systemic therapy for managing chronic osteomyelitis and acute musculoskeletal infections. Numerous antibiotics are available for use in polymethylmethacrylate. However, specific characteristics should be considered prior to therapeutic selection: the antibiotic should be water-soluble, bactericidal, nontoxic to tissues, and readily available in powder form. In this concluding segment, the organisms most commonly cultured from orthopaedic infections and appropriate combinations of antibiotics and bone cements are outlined.

Factors in pin tract infections

To determine the factors pertinent to the etiology of pin tract infections, 214 pins in 42 patients were examined prospectively at the time of pin removal. Eighty-nine (41.6%) pin tracts were inflamed, 49 (22.9%) pins had loose anchorages, and 160 (74.8%) pin tips cultured positive for bacteria. The predominant organism cultured was Staphylococcus epidermidis (90.6%), considered nonvirulent, followed by virulent Staphylococcus aureus (37.5%), and Escherichia coli (9.4%). There were 32 loose, inflamed pin tracts. This correlation was statistically significant (P less than .005). There were 40 loose pins whose pin tips had positive cultures. Loose pins correlated for infection with virulent species of bacteria at a highly significant level (P less than .005). Results demonstrate that most pins possess bacterial colonization. Clinically, this means that either inflamed pin tracts or pins with cultures positive for invasive organisms are probably loose and should be removed. Also, mechanical factors are the critical variable in determining the flora of external fixation pins.

Antibiotic-impregnated beads. Part I: Bead implantation versus systemic therapy

Parenteral antibiotic therapy for acute bone infections, soft-tissue infections, and osteomyelitis may result in high serum concentrations associated with nephrotoxic, ototoxic, and allergic complications. Conversely, the local release of antibiotics into the wound with the use of antibiotic-impregnated cement or antibiotic-impregnated polymethylmethacrylate beads has been found effective and does not induce negative effects or result in systemic concentrations of clinical significance. The antibiotic-impregnated cement beads are fabricated on a surgical steel wire, and they have bimodal elution properties. They provide local antibiotic concentrations that surpass the minimum inhibitory concentrations for pathogens commonly isolated in orthopaedic infections. Their use effectively controls chronic osteomyelitis and acute musculoskeletal infections. Compared with systemic antibiotic therapy, the incidence of nephrotoxic, ototoxic, and hypersensitivity reactions is significantly diminished. The beads release 5% of the antibiotic within the first 24 hours. The sustained elution then progressively diminishes to undetectable levels within a few weeks or months.

The prophylactic use of antibiotic impregnated beads in open fractures

Four hundred four compound fractures were reviewed in 339 patients treated between August 1983 and November 1987. The 252 males and 87 females had a mean age of 33 years (range, 14-86). One hundred twenty-seven (31.4%) fractures were classified as Grade I, 153 (38.9%) as Grade II, and 124 (30.7%) as Grade III by Gustilo's classification. The mean Injury Severity Score was 15 (range, 9-57). Three hundred thirty-four of the open fractures (82.7%) were managed with antibiotic-impregnated bead chains (tobramycin) and systemic antibiotic prophylaxis (cefazolin, tobramycin, and penicillin). Seventy open fractures (17.3%) received systemic antibiotic prophylaxis (cefazolin, tobramycin, and penicillin) without supplemental use of the antibiotic beads. All open fractures underwent acute irrigation and debridement. In the 404 fractures 46.5% of wounds were closed primarily, 12.9% underwent delayed primary closure, 7.9% were left open, and 32.7% were temporized by the antibiotic bead pouch technique until definitive flap coverage and skin grafting were performed. Of the 404 fractures evaluated, 17 (4.2%) developed an acute wound infection. Of these wound infections, eight (11.4%) were in the group managed with systemic antibiotics alone. By comparison, nine (2.7%) of open fractures treated with combined systemic antibiotics and antibiotic-impregnated beads developed an infection. Chronic osteomyelitis developed in 18 of 404 open fractures (4.5%). Ten (14.3%) open fractures which developed osteomyelitis were managed with systemic antibiotics whereas eight (2.4%) fractures managed with systemic antibiotics and antibiotic-impregnated beads developed a chronic infection.(ABSTRACT TRUNCATED AT 250 WORDS)

[Treatment of unstable thoracic and lumbar spinal fractures with Cotrel-Dubousset instruments]

The present study is a retrospective analysis of first experiences of fracture treatment with the Cotrel-Dubousset instrumentation technique. Thirty-five unstable spine fractures were treated with the CD implant at the University of Louisville--Level I Trauma Center--between June, 1985 and August, 1987. There were 17 burst fractures, 12 compression fractures and 2 fracture dislocations, 2 flexion distraction fractures and 2 flexion rotation injuries. Twenty patients underwent anterior cord decompression and strut grafting followed by posterior CD instrumentation and posterolateral fusion. Fifteen patients had posterior CD instrumentation and fusion alone. No neurological deterioration after the procedure was observed, 5 patients improved neurologically. In eleven cases bracing after the operation was unnecessary. Hospital stay varied between 6 and 35 days (mean 20 days). Follow-up ranged from 12 to 30 months, mean follow-up was 19 months. The loss of correction in the sagittal plane varied between 0 and 20 degrees (mean 5.6) at final follow-up. Complications due to the implant have not been observed except an avulsion of an upper thoracic hook, which did not effect the clinical or radiographic result. The high stability of the implant provides a decreased risk of neurological deterioration, posttraumatic kyphosis as well as early rehabilitation.

A preliminary experience: the Ilizarov external fixator

The Ilizarov external fixator, though developed over 35 years ago in the Soviet Union, is only now gaining popularity in the United States. Its design and versatility allow the physician to treat a wider range of limb maladies than other external fixation systems (eg, the Hoffmann device). The Ilizarov method of fixation also permits treatment of some orthopedic conditions that were previously considered to be untreatable, such as dwarfism. The device can be used to correct limb length discrepancies, manage open and closed fractures, nonunions, and bony or soft tissue deformities. A review of the first 25 cases performed at the University of Louisville revealed 15 which have been successfully completed with significant, but manageable complications, and 10 cases which are still in progress.

[Treatment of 2d and 3d degree complicated tibial shaft fractures with the PMMA bead pouch technic]

In a consecutive series of 222 compound fractures treated at the University of Louisville Level I Trauma Center from November 1984 to January 1987, 21 severe compound tibia shaft fractures in 20 patients were managed with the antibiotic bead pouch technique. There were 5 tibia shaft fractures and 16 tib-fib fractures. There were 9 type II and 12 type III (4 III A and 8 III B) open tibias. The patients' ages ranged from 16 to 50 years; the mean age was 29 years. There were 19 men and 1 woman. The Injury Severity Score (I.S.S.) ranged from 9 to 34; the mean I.S.S. was 14.4. Porous plastic film (Opsite) is placed over the soft tissue defect to establish a "closed" bead - hematoma - fracture environment containing high local levels of antibiotic at the fracture site. All patients had external skeletal fixation, serial wound débridement, and parenteral systemic antibiotics (cefazolin, penicillin, tobramycin). An aggregate of 46 bead pouch changes were performed in the 21 tibia fractures. During these changes, 86 cultures were taken, 5 of which were positive. One patient developed a wound infection, which was caused by tobramycin-resistant Pseudomonas and Enterococcus. No cases of osteomyelitis were observed at the fracture site. Wound closure was obtained in 9 fractures with delayed primary closure, and in 12 fractures with flap coverage and/or split thickness skin grafting. All patients underwent autogenous cancellous bone grafting after wound closure was established. The mean follow-up was 26 months (range 13-43 months). At final follow-up, 4 results were rated excellent, 11 good, 3 fair and 3 poor.(ABSTRACT TRUNCATED AT 250 WORDS)

Wound and serum levels of tobramycin with the prophylactic use of tobramycin-impregnated polymethylmethacrylate beads in compound fractures

Antibiotic-impregnated polymethylmethacrylate (PMMA) beads have been useful in treating orthopedic infections. Local delivery has been reported to establish wound antibiotic levels well above the therapeutic range while avoiding serum levels associated with increased incidence of side effects. After operative debridement, 70 patients with compound fractures were treated prophylactically with tobramycin-impregnated PMMA beads. Observations of antibiotic levels in 27 patients demonstrated antibiotic levels in the wound drainage and clot that were significantly in excess of the usual therapeutic range for tobramycin and simultaneous nontoxic serum levels. Significant levels of tobramycin can be achieved in the extracellular fluid at the fracture site when tobramycin-impregnated PMMA beads are placed in the wound after irrigation and debridement.

Heat of intramedullary reaming

Cortical ischemia and necrosis after intramedullary reaming are well documented. Numerous authors have described ischemic changes attributed to mechanical disruption of the arterial system of the intramedullary canal. Few have investigated the potential thermal injury during extreme temperatures generated during intramedullary reaming. We reamed the medullary canal of cadaveric tibial and femoral diaphyses using a flexible shaft reaming device and stainless steel intramedullary reamer. The temperatures generated by reaming from 11 mm through 15 mm in 1 mm increments were measured after each pass. In the 17 specimens tested, we observed an incremental rise in temperature with reaming. The mean intramedullary temperature after reaming was 52 C ( +/- 8.3) with a range of 42 to 67 C. The mean extramedullary temperature was 46 C ( +/- 8.3) with a range of 36 to 59 C. There was a direct correlation between temperature increase and reamer size. Our results indicate that temperature elevations generated during intramedullary reaming are sufficient to cause thermal necrosis, and may cause delayed healing in vivo.

Role of calcium and prostaglandins in the antidiuretic hormone response. Effect of ionophore A23187

The calcium ionophore A23187 (IP) inhibited the antidiuretic hormone (ADH)-stimulated hydro-osmotic response in toad urinary bladder but had no effect on the osmotic transfer of water in the absence of hormone. Extracellular calcium was necessary for this effect at lower but not at higher IP concentrations. The hydro-osmotic response to exogenous cyclic AMP was unaltered by IP, but the same response produced by inhibition of phosphodiesterase was reduced significantly. Cyclic AMP concentrations in isolated toad bladder epithelial cells were reduced by 50% with IP or exogenous prostaglandin E2 (PGE2). Indomethacin, a prostaglandin synthesis inhibitor, prevented the inhibitory actions of the IP on the ADH-mediated response. Collectively, these observations suggest a key role for cellular calcium in modulating the actions of antidiuretic hormone and are consistent with the hypothesis that the ionophore, through increasing intracellular calcium, stimulates the synthesis of prostaglandins which have a negative feedback on adenylcyclase. This effect would terminate the action of the hormone.

Proteolytic Activity in Ultra-Pasteurized, Aseptically Packaged Whipping Cream 1

The proteolytic activity in three commercial ultra-pasteurized, aseptically packaged samples of cream that developed bitter flavor was studied. Samples were analyzed for microorganisms and rate of proteolysis as affected by reaction temperature and pH. The temperature effect was determined at 20, 30, 37, 45, and 50 C. Samples A and B had an optimum temperature of 37 C for proteolytic activity while Sample C had its optimum between 30 and 37 C. Sample B had increased activity at pH 7.0, 8.0 and 9.0. Sample A had increased activity between pH 7.0 and 7.5 while Sample C exhibited greatest activity at pH 8.0. The rate of proteolysis increased with incubation time.