Biomedical subjects

J O Anglen

Publications and source records attributed to J O Anglen.

35 records · Page 2Linked to original sources

PubMed1997

The significance of positive cultures from orthopedic fixation devices in the absence of clinical infection.

Microbiologic samples for culture were obtained from 21 patients during elective removal of fracture-fixation hardware. The hardware was being removed for pain, displacement, nonunion or malunion correction, or patient preference. None of the patients had evidence of infection as determined by medical history, physical examination, white blood count, and sedimentation rate performed on the day of hardware removal. Two sets of culture samples were obtained from each patient: swabs of the wound and of the hardware were obtained and processed by the hospital laboratory. Eleven hardware cultures and nine wound cultures were positive for microbiologic growth. None of the patients was treated with antibiotics, and none developed any problems with wound infection or healing nor any evidence of osteomyelitis. We concluded that positive cultures obtained during hardware removal in the absence of clinical signs of infection are not meaningful.

Adolescent↗

PubMed1996

Disinfecting agents for removing adherent bacteria from orthopaedic hardware.

This investigation seeks to determine whether surfactants or detergents can be used to clean and disinfect orthopaedic wounds with implanted hardware. Thus, a stepwise investigation of biocompatible surfactants and detergents was performed to identify an irrigation agent for disinfecting orthopaedic wounds. Bacterial adhesions assays, irrigation studies, and bactericidal assays determined that benzalkonium chloride showed the greatest efficacy. Testing involved stainless steel screws colonized with a preformed biofilm of Staphylococcus epidermidis, Staphylococcus aureus, or Pseudomonas aeruginosa, which were immersed in benzalkonium chloride solutions for various time intervals under static conditions. After 10 minutes, benzalkonium chloride achieved a minimum 4 log kill (10,000-fold) for all 3 strains of bacteria. Additional studies demonstrated that the high mechanical energy of jet irrigation improved the disinfecting properties of this agent. With jet lavage, both 1:1000 and 1:5000 concentrations of benzalkonium chloride achieved a minimum 2 log kill (100-fold) for all 3 bacteria. The results or this study suggest that at tissue compatible concentrations, benzalkonium chloride has significant disinfection properties for in vitro colonized orthopaedic devices, and these properties may be enhanced via jet lavage.

Anti-Infective Agents, Local↗

PubMed1996

Prevention of heterotopic bone formation after acetabular fracture fixation by single-dose radiation therapy: a preliminary report.

A common complication after acetabular fracture fixation is formation of heterotopic ossification (HO) in the soft tissues about the hip. We are reporting on the use of a single, low-dose radiation therapy regimen to prevent HO in the population of postoperative acetabular fracture patients. Thirty acetabular fracture patients who were at risk for HO after surgery were reviewed with an average follow-up of 12 months. Twenty-one of these patients received radiation therapy in the postoperative period according to a single dose protocol. Nine patients did not receive any prophylactic treatment for the prevention of HO during the same period. One patient from each of these categories was lost to follow-up. Of the 20 treated and followed patients, none developed HO higher than grade 2, and nine had no HO at all. None of the treated patients had any functional deficit due to HO, and none had any complications related to radiation treatment. Of the untreated patients, all had grade 2 HO or above. Three developed grade 4 HO and have undergone reoperation for resection of HO. Study weakness include the fact that the non-treated patients were significantly different from the treated patients in several ways; including the incidence of multiple trauma, head injury, and delay to surgery. No attempt was made to randomize patients prospectively, nor to directly compare the two groups. However, we can conclude, based on comparison with reported rates of HO formation, that single, low-dose radiation therapy is a safe and effective method for prevention of HO in the postoperative acetabular fracture patient. It is as effective as previously reported multidose regimens.

Acetabulum↗

PubMed1996

Irreducible fracture of the calcaneus due to flexor hallucis longus tendon interposition.

An unusual fracture-dislocation of the calcaneus is presented in which tendinous interposition in the subtalar joint prevented the possibility of closed reduction. This situation has been reported in the literature in only five previous patients. The position of the flexor hallucis tendon in the joint could be visualized on the preoperative computed tomographic scan. The patient was treated operatively with reduction through a lateral approach without a supplemental medial incision.

Adult↗

PubMed1996

Titanium plate fixation: a review of implant failures.

Titanium plates and screws have become widely used for the fixation of fractures and osteotomies. We began using them in 1992; however, several early hardware failure prompted a retrospective review of the occurrence of this complication. A 2-year time period was reviewed at two institutions with comparison of hardware failure rates using titanium and stainless steel implants. At one institution, 51 fractures or osteotomies of the long bones were fixed by the senior author using titanium implants between July 1992 and July 1994. One hundred one similar cases were treated over the same period by the same surgeon using stainless steel implants. The outcome is known for 48 of the cases performed with titanium and for 80 of the cases performed with stainless steel. There were five postoperative implant failures using titanium and one using stainless steel. Metallurgical analysis of one set of broken implants retrieved during a revision surgery showed no manufacturing defects. At the second institution, 21 titanium and 138 stainless steel platings were performed over 2 years. There were four titanium implant failures in four patients and one stainless steel implant failure. Our experience suggests that these implants should be used with care, particularly in high-demand settings such as nonunion or noncompliance, and that further research needs to be conducted to establish appropriate clinical indications for their usage.

Adolescent↗

PubMed1995

A comparison of reamed and unreamed nailing of the tibia.

The availability of unreamed interlocked nails for fixation of tibia fractures has raised the issue of what effect reaming the intramedullary canal has on the clinical outcome after tibial nailing. A retrospective review was performed of all tibial fractures treated with interlocking nailing at the authors' institution over the past 5 years in order to compare reamed and unreamed nailing. Forty-five nailings were identified of which 38 had adequate follow-up information to be considered healed or non-united at 1 year. Thirteen reamed and 23 unreamed tibial nailings were followed to healing; there were 6 nonunions. The unreamed nailings had lower average operative times and lower average estimated blood loss, although the results did not reach statistically significant levels. There was a statistically significant difference in healing times, with unreamed nailings taking an average of 242 days to heal while reamed nailings took 158. This difference held for subgroups such as isolated tibia fractures, closed tibial fractures, and high-energy tibial fractures. Six non-unions occurred, one in a reamed nailing and five in unreamed nailings. Malunions occurred in four reamed nailings and six unreamed nailings, most often in distal third fractures, interlocked on only one side of the fracture. Patellofemoral complications were more common in unreamed nailings. Although this study is limited by retrospective, nonrandom design, it raises questions about the routine use of unreamed nailing with regard to healing potential and other postoperative complications. Further study is warranted.

Adolescent↗

PubMed1995

Oblique osteotomy for the correction of tibial malunion.

Fifteen patients had an oblique osteotomy of the tibia for the correction of a multiplanar deformity between January 1989 and March 1991; twelve were followed for an average of twenty-five months (range, twelve to forty-two months). Preoperatively, the average deformity in the coronal plane was 14 degrees (range, 30 degrees of valgus to 25 degrees of varus) and the average deformity in the sagittal plane was 13 degrees (range, 40 degrees of recurvatum to 23 degrees of procurvatum [angulation convex anteriorly]). The average leg-length discrepancy was 2.2 centimeters (range, one to six centimeters). No patient had a rotational deformity. After careful preoperative planning, all patients had an oblique osteotomy and placement of a lag screw and a neutralization plate. Somatosensory evoked potentials were monitored during any axial lengthening. A fibular osteotomy and lengthening of the Achilles tendon were performed as needed. Full weight-bearing on the extremity was prohibited until radiographic and clinical examination indicated that union had occurred, which was at an average of 4.5 months (range, three to six months). At the most recent follow-up examination, ten patients had an excellent result. The average correction in the coronal plane was to within 1 degree (range, 0 to 3 degrees) of normal and the average alignment in the sagittal plane was to within 2 degrees (range, 0 to 12 degrees) of normal. An average of 1.3 centimeters (range, 0.5 to 2.5 centimeters) of lengthening was obtained.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1995

Decisions in severe extremity trauma.

Advances in the management of severe extremity trauma have allowed treatment of injuries previously resulting in amputation or death. The variety of new techniques and technologies available to the orthopedic traumatologist and the trauma team can lead to functional salvage of limbs if crucial management decisions are made correctly in the course of treatment. Accurate knowledge of the potentials and pitfalls of extremity trauma treatment can help to identify salvageable limbs, as well as those doomed to failure so that costly and painful courses of futile treatment can be avoided.

Amputation, Surgical↗

PubMed1994

The efficacy of various irrigation solutions in removing slime-producing Staphylococcus.

To determine which type of irrigation solution and which method of irrigation most effectively removes slime-producing Staphylococcus from implant surfaces, we performed experimental washings of bacteria-coated stainless steel screws with various solutions delivered by bulb syringe or by jet lavage. The quantity of bacteria remaining on the screw surface was determined after irrigation with 1 L of saline, 1 L of antibiotic solutions, or 1 L of saline containing a liquid soap. Antibiotic solutions tested included bacitracin, neomycin, and polymyxin/neomycin. We found that the use of power irrigation increased the removal of bacteria by a factor of at least 100 over bulb syringe irrigation of the same volume, no matter which solution was used. This effect ranged from a 100-fold improvement for neomycin, to a 285-fold effect for the polymyxin solution. The addition of antibiotic drugs to the irrigation solution had no significant effect on bacterial removal, and none of the antibiotic solutions were statistically different from saline alone in the amount of bacteria removed from the screws. The addition of a liquid soap solution dramatically increased the amount of bacteria removed by irrigation, reducing the residual bacteria per screw from a colony count of 3.5 x 10(4) for polymyxin (the best of the antibiotic solutions), to 4.38 x 10(3). This difference was statistically significant as judged by Student's t test, with p = 0.01. We have concluded that the use of power irrigation improves the ability to clean this pathogenic bacteria from metallic surfaces, and that the addition of antibiotic drugs to the irrigation solution does not.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Bacterial Agents↗

PubMed1994

The reliability of detecting screw penetration of the acetabulum by intraoperative auscultation.

Open reduction and internal fixation of the acetabulum frequently requires placement of screws in a blind fashion that risks penetrating the joint surface. While in the operative suite, direct visualization of the joint surface may not be possible, and fluoroscopy can be difficult to interpret. Auscultation of the hip with motion in a quiet room has been suggested as a useful adjunct to detecting screw penetration. Carrying that concept further, we auscultate the hip using a sterile esophageal stethoscope at the operating table and have found this to be a highly reliable method of detecting intraarticular screw placement. To test the reliability and reproducibility of this technique, an experiment was performed using inexperienced volunteers. In part I, two adult mongrel dogs were prepared. A screw was placed violating the hip joint in one dog, and in the other dog a screw was placed near but not penetrating the joint. Screw placement was verified under direct vision. Seventy-seven volunteers who did not know which hip was penetrated then auscultated both hips in random order and recorded their impressions after each hip was heard. After hearing both hips, 74 of 77 were able to identify the screw in the hip joint correctly; 69 were able to recognize the extraarticular screw correctly. In part II, both hips of a human cadaver were exposed and dislocated. In one hip, a screw was placed that tangentially violated the joint, and in the same area of the contralateral hip a screw was placed that did not penetrate the joint surface.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetabulum↗

PubMed1993

Advances in the treatment of calcaneus fracture.

The calcaneus is the largest of the tarsal bones and the most commonly fractured, being involved in more than half of all major tarsal injuries. Intraarticular fractures of the calcaneus are seriously disabling and of significant economic consequences. Ninety percent of these injuries occur in working age men, most commonly industrial workers. Many of these workers will never return to their jobs, and of those who do, 20% will be out for up to 3 years. The optimal treatment for intra-articular fractures is controversial. However, in the past few years, progress has been made in understanding the nature of calcaneus fracture. The availability of computed tomographic scanning and improved surgical techniques has improved the outlook for many of these patients to return to productive activity.

Calcaneus↗

PubMed1988

Tibial plateau fractures.

A retrospective study of 128 patients with fractures of the tibial plateau treated at the Johns Hopkins Medical Institutions over a 20-year period was undertaken to compare the results of operative treatment with the results of the nonoperative treatment. Outcome was evaluated with respect to healing, length of hospital stay, time to weight bearing and full activity, and functional result. The fractures were grouped into the four types of the Association for the Study of the Problems of Internal Fixation (AO/ASIF) system, with nondisplaced fractures considered separately. Overall, patients with displaced fractures treated operatively had a shorter average hospital stay (22 days vs 26 days), a higher percentage of satisfactory functional results (78% vs 63%), and a shorter period of immobilization (5 weeks vs 10 weeks), but took longer to return to prefracture activity level (23 weeks vs 18 weeks). The patients treated operatively had more complications with regard to infections (9 vs 2), fewer complications with regard to thromboembolism (2 vs 13), and approximately equal numbers of nonunion or malunion. Our study supports operative therapy for patients with displaced Type III or Type IV fractures and closed treatment for patients with Type I, Type II, and nondisplaced fractures.

Activities of Daily Living↗

PubMed1988

Distal femoral varus osteotomy.

The results of twenty-three distal femoral varus osteotomies (in twenty-one patients) that were performed between 1977 and 1984 were evaluated. Fifteen osteotomies were done for osteoarthritis; three, for post-traumatic arthritis or deformity; three, for rheumatoid arthritis; and two, for renal osteodystrophy. The median age of the patients was fifty-six years (range, nineteen to seventy years). The length of follow-up averaged four years (range, two to nine years). The average tibiofemoral angle preoperatively was 18 degrees of valgus, which was corrected postoperatively to an average of 2 degrees of valgus. At follow-up, nineteen (83 per cent) of the twenty-three knees were rated as good or excellent according to The Hospital for Special Surgery knee score, which had improved from an average of 65 points preoperatively to 86 points post-operatively. Of the fifteen patients who had osteoarthritis (93 per cent), all but one had a good or excellent result. Most patients had no substantial improvement in the range of motion of the knee as a result of the operation. Eighty-six per cent of the patients expressed satisfaction with the outcome. We concluded that varus osteotomy of the distal part of the femur is a reliable and effective surgical procedure for the treatment of gonarthrosis associated with valgus deformity due to osteoarthritis or trauma. We do not recommend its use in patients who have rheumatoid arthritis or in those who have inadequate motion of the knee before the operation.

Adult↗

PubMedDate not supplied

Benzalkonium chloride: a potential disinfecting irrigation solution.

OBJECTIVE: To determine the disinfecting properties of benzalkonium chloride as an irrigation agent. DESIGN: Comparison was made between irrigation of contaminated muscle strips with benzalkonium chloride and normal saline (control). SUMMARY OF BACKGROUND DATA: Benzalkonium chloride is a cationic disinfectant, which has questionable efficacy in an organic environment. However, no previous study has attempted to use high volumes of this cationic solution to overcome the neutralizing effect of organic tissue and thus maintain this detergent's germicidal properties. METHODS: 2.5 cm x 0.5 cm x 0.5 cm pieces of bovine muscle were aseptically cut from the center of freshly harvested beef muscle and incubated with 1.0 x 10(7) colony forming units of bacteria for 15 minutes. The muscle strips were then irrigated with either 100 mL, 1 L, or 10 L of benzalkonium chloride at a 1:2000 concentration in normal saline. Normal saline was used as the control. The muscle strips were sonicated to remove adherent bacteria; the number of living organisms was determined by quantitatively culturing the sonicate. RESULTS: In vitro, benzalkonium chloride was superior to normal saline at disinfecting bovine muscle (p < or = 0.001). When 10 L of benzalkonium chloride irrigation was used, no living bacteria could be recovered (p < or = 0.012). CONCLUSION: In this experimental setting benzalkonium chloride was an effective disinfection agent, with enhanced activity at large volumes.

Animals↗

PubMedDate not supplied

Comparison of castile soap, benzalkonium chloride, and bacitracin as irrigation solutions for complex contaminated orthopaedic wounds.

OBJECTIVE: The purpose of the present study was to determine the effects of cleaning a contaminated orthopaedic wound with different classes of wound irrigation solutions. STUDY DESIGN: Rats with a contaminated orthopaedic wound were randomized into treatment groups: normal saline (NS), castile soap (CS), benzalkonium chloride (BzC), bacitracin (Abx), or sequential irrigation with BzC, CS, and NS. INTERVENTION: Pseudomonas aeruginosa [P. aeruginosa; 1 x 10(6) colony-forming units (CFU)], or Staphylococcus aureus (S. aureus; 1 x 10(6) CFU) were placed into a paravertebral wound (containing a wire implant placed through a spinous process) and allowed to incubate for fifteen minutes. The wound was then irrigated with three liters of either NS, 0.05 percent CS, 0.03 percent BzC, Abx (33,000 units per liter) or underwent a sequential irrigation treatment (one liter each of BzC, CS, NS). MAIN OUTCOME MEASUREMENTS: The animals were observed daily for wound complications for fourteen days and then killed, and cultures of the wound were obtained. RESULTS: Pseudomonas aeruginosa: Both CS and the sequential irrigation treatment significantly lowered the rate of positive wound cultures when compared with NS (p < 0.05). Irrigation with BzC resulted in a higher rate of positive wound cultures and complications. The sequential irrigation treatment prevented the wound complications associated with irrigation with BzC alone. Staphylococcus aureus: Only BzC irrigation significantly lowered the rate of positive wound cultures when compared with NS (p < 0.05). CONCLUSION: The rate of positive wound cultures due to P. aeruginosa is effectively reduced by irrigation with CS alone or by the sequential irrigation treatment. When used alone, the antiseptic BzC results in a higher rate of positive wound cultures and wound complications. The wound complications seen with irrigation with BzC alone are prevented by the sequential irrigation treatment (BzC followed by CS and NS). The rate of positive wound cultures in this model due to S. aureus is not decreased by irrigation with CS; however, the rate of positive wound cultures is safely and effectively decreased with the use of BzC.

Animals↗

PubMedDate not supplied

Wound irrigation in musculoskeletal injury.

Wound irrigation to remove debris and lessen bacterial contamination is an essential component of open fracture care. However, considerable practice variation exists in the details of technique. Volume is an important factor; increased volume improves wound cleansing to a point, but the optimal volume is unknown. High-pressure flow has been shown to remove more bacteria and debris and to lower the rate of wound infection compared with low-pressure irrigation, although recent in vitro and animal studies suggest that it may also damage bone. Pulsatile flow has not been demonstrated to increase efficacy. Antiseptic additives can kill bacteria in the wound, but host-tissue toxicities limit their use. Animal and clinical studies of the use of antiseptics in contaminated wounds have yielded conflicting outcomes. Antibiotic irrigation has been effective in experimental studies in some types of animal wounds, but human clinical data are unconvincing due to poor study design. There are few animal or clinical studies of musculoskeletal wounds. Detergent irrigation aims to remove, rather than kill, bacteria and has shown promise in animal models of the complex contaminated musculoskeletal wound.

Animals↗

PubMedDate not supplied

Heterotopic ossification in rehabilitation patients who have had internal fixation of an acetabular fracture.

High-energy trauma patients often have multiple injuries and are frequently seen by a physiatrist following their acute care. Acetabular fractures are common in this patient population. Following surgical treatment of acetabular fractures, a very high incidence of heterotopic ossification can occur. We describe 94 patients who underwent posterior surgical fixation of an acetabular fracture. Of these, 87 received heterotopic ossification prophylaxis in the form of irradiation or indomethacin; 5 did not receive prophylaxis. Seven of the 45 patients who were initially started on indomethacin had their medication discontinued for various reasons. Of the 12 patients who did not receive adequate prophylaxis, 5 developed disabling heterotopic ossification. We present our experience with this patient population, and we discuss the importance of adequate prophylaxis for heterotopic ossification.

Acetabulum↗