Orthopedic Wound Research Articles

Comparison of Bulb Syringe and Pulsed Lavage Irrigation With Use of a Bioluminescent Musculoskeletal Wound Model: Svoboda SJ, Bice TG, Gooden HA, et al. J Bone Joint Surg Am 2006;88:2167–74

The focus of this study was to ascertain the superiority of pulsed lavage irrigation in removing bacteria from a complicated orthopedic wound in 12 male Spanish-Boer goats. The animals all received a 5-cm incision to the tibial tubercle of the left lower extremity, which included crush injury to the anterior muscle compartment, thermal injury from electrocautery, periosteal elevation from the bone, and cortical bone compromise with a drill twist-bit. Next, the wounds were inoculated with bioluminescent strains of Pseudomonas aeruginosa and allowed to incubate for 6 hours.

Combat Orthopaedics: A View From the Trenches

Approximately 70% of war wounds involve the musculoskeletal system, and military orthopaedic surgeons have assumed a pivotal role in the frontline treatment of these injuries in Iraq. Providing battlefield orthopaedic care poses special challenges; not only are many wounds unlike those encountered in civilian practice, but patients also must be triaged and treated in an austere and dangerous environment, undergo staged resuscitation and definitive surgery, and endure prolonged medical evacuation, often involving ground, helicopter, and fixed-wing transport across continents. Most orthopaedic wounds in Iraq are caused by exploding ordnance--frequently, improvised explosive devices, or IEDs. Because of advances in care, rapid medical evacuation, and modern body armor, many casualties have survived in Iraq who would not have done so in previous wars. Treatment of war wounds, many of which are devastating in the scope of soft-tissue and bony injury, requires a team approach using hypotensive resuscitation, damage-control orthopaedics, new or rediscovered techniques of hemostatic and intravenous hemorrhage control, vacuum-assisted wound closure, and advanced reconstruction. Current challenges include prevention of infection, a better understanding of heterotopic ossification as a sequela of blast injury, and the need for a comprehensive, joint service database that encompasses the multilevel spectrum of orthopaedic care.

Reduction of orthopaedic wound infections in 21 hospitals

The German national nosocomial infections surveillance system (KISS) has been collecting surveillance data from hip and knee prosthesis operations since 1997. The purpose of this article is to investigate whether surveillance and feedback of surgical site infection (SSI) information to the physicians and nurses of participating hospitals lead to reduced SSI rates or not. Only information from hospitals previously participating for at least 3 years was used for the analysis. Monthly SSI rates were pooled over the 36-month period, beginning in each clinic's case with its first month of participation, the rates then being compared for 12-month periods. Relative risks were calculated for comparison of the SSI rates in the first and third years of participation. A multiple logistic regression analysis with stepwise variable selection was performed to identify significant risk factors, including the year of surveillance after starting surveillance activities. The overall SSI rates were 1.4% for hip prosthesis and 1.0% for knee prosthesis. Fourteen clinics participated in KISS for at least 3 years continuously with HIP prostheses and 21 with knee prostheses. It was possible to include a total of 15,457 hip and 9,011 knee procedures for this analysis. A comparison of data from the first and the third years show a significant SSI reduction with hip procedures, with a relative risk of 0.54 (CI95 0.38-0.77), and a trend towards reduced SSI rates for knee procedures. The multiple logistic regression analysis confirmed that the SSI rate for hip prosthesis was significantly lower in the third year than in the first year of surveillance (OR = 0.57; CI95 0.42-0.78), though for knee prosthesis the level of significance was not achieved. A reduction of SSIs following hip and knee prosthesis operations through the introduction of ongoing surveillance and the possibility of using benchmark data for comparison does seem to be possible in many institutions.

Local Antibiotic Delivery Systems

Local Antibiotic Delivery Systems

Wound Healing

Wound healing in orthopaedic care is affected by the causes of the wound, as well as concomitant therapies used to repair musculoskeletal structures. Promoting the health of the host and creating an environment to foster natural healing processes is essential for helping to restore skin integrity. Normal wound healing physiologic processes, factors affecting wound healing, wound classification systems, unique characteristics of orthopaedic wounds, wound contamination and drainage characteristics, and potential complications are important to understand in anticipation of patient needs. Accurate wound assessment and knowledge of nursing implications with specific wound care measures (cleansing, debridement, and dressings) is important for quality care. New technologies are enhancing traditional wound care measures with goals of effective comfortable wound care to promote restoration of skin integrity.

Choice of dressing has a major impact on blistering and healing outcomes in orthopaedic patients

To investigate the effect of three postoperative dressings on orthopaedic wound healing. Three hundred orthopaedic patients were divided into three treatment groups and allocated to management with one of three dressings: Primapore, Tegaderm with pad, and OpSite Post-Op. Staff completed a questionnaire to evaluate the wound progression. Outcome measures were the presence of infection, blistering and the number of dressing changes required. There was a significantly lower incidence of blistering with OpSite Post-Op (6%) than Tegaderm with pad (16%) and Primapore (24%) (p<0.001). Patients in the OpSite Post-Op group had the lowest exudate levels. Dressings that employ a clear film and have a high moisture vapour transmission rate have been shown to reduce both the rate of blistering and wound discharge. The additional expense inherent in using such dressings may, in reality, prove cost-effective because of the reduced need for dressings changes and the subsequent earlier discharge of these patients from hospital with an uncomplicated wound.

Eradication by Surfactant Irrigation of Staphylococcus aureus from Infected Complex Wounds

Treatment of infected orthopaedic hardware usually requires the removal of the appliance. When the device is removed and immediately replaced, persistent infection frequently complicates this exchange procedure. We modeled the exchange procedure in rats by passing a wire suture through a posterior spinous process and then contaminating the wound with Staphylococcus aureus. We then investigated whether a sequence of surfactant enriched irrigation solutions (Castile soap followed by benzalkonium chloride, sequential surfactant irrigation) had a greater capacity to eradicate Staphylococcus aureus from the experimental wound than did the standard wound irrigant, normal saline. When we left the wire in place through the 2-week course of the study, sequential surfactant irrigation showed only a modest advantage over normal saline (staphylococci recovered from 39% versus 58% of wound cultures respectively). Simple removal of the wire 24 hours after implantation and bacterial contamination prevented wound infection in most animals (with the wire removed, 38% of the animals remained infected versus 85% with the wire left in place), without regard to the irrigation solution. Alternatively, when we removed the wire after 24 hours, irrigated the wound, and then placed a fresh wire back into the wound, sequential surfactant irrigation showed a significant advantage over NS (54% of the animals irrigated with sequential surfactants remained infected versus 100% of the animals irrigated with normal saline). Our findings confirm the importance of a contaminated medical device for promoting foreign body infection; our findings also show that sequential surfactant irrigation has therapeutic value in a rat model of orthopaedic device infection; this irrigation protocol should be studied further as a potential agent for the treatment of infected orthopaedic wounds.

Comparison of clips versus sutures in orthopaedic wound closure

A prospective randomised trial was conducted to compare the use of skin clips versus interrupted nylon sutures in uncomplicated orthopaedic wound closure. Non-blinded wound assessment for complications and outcome (cosmesis) was performed on day 13 when the clips/sutures were removed. Average time for removal of each clip/suture was calculated for each wound. Also, an assessment of patient pain during removal was made using a patient-completed visual analogue scoring system (VAS). No statistically significant difference was found in wound healing and cosmesis between the clip and suture group at follow-up. Clip removal with the special clip remover was found to be quicker and less painful (p=0.001). There was good patient satisfaction with the use of skin clips over nylon sutures. We recommend the use of skin clips, using an assistant to evert the wound edges, as an efficient form of wound closure in most uncomplicated orthopaedic procedures.

Musculoskeletal War Wounds during Operation BRAVA in Sri Lanka

Operation BRAVA (Blast Resuscitation and Victim Assistance) was conceived as a means of conducting humanitarian assistance, education, and training in the acute surgical management of land mine and other blast injuries. The first Operation BRAVA mission was carried out in Sri Lanka during 1998 at a time of civil war between government forces and Tamil separatists. Thirty-seven patients with orthopedic war wounds were seen during this mission because of the fighting. Exploding ordnance injured 24 patients (65%), and 13 patients (35%) sustained gunshot wounds. Sixty-seven percent of explosive injuries were from mortar rounds, and the remainder was from a variety of detonating munitions. Twenty-two patients (59%) sustained injuries to one or both lower limbs, and compartment syndrome of the leg developed in two of these patients as a result of multiple fragment injuries. Nine patients (24%) sustained concomitant neurological or vascular injuries. Operation BRAVA provided a novel approach to enhancing the combat medical skills of U.S. military personnel and was successful in developing working relationships with host country medical professionals, facilitating participation in the care of wounded patients, and establishing a framework upon which future BRAVA teams might build.

Complex Orthopaedic Wounds: Prevention and Treatment with Negative Pressure Wound Therapy

Complex Orthopaedic Wounds: Prevention and Treatment with Negative Pressure Wound Therapy

Complex Orthopaedic Wounds: Prevention and Treatment with Negative Pressure Wound Therapy

Complex Orthopaedic Wounds: Prevention and Treatment with Negative Pressure Wound Therapy

Effect of Antibiotics on Cell Surface Hydrophobicity of Bacteria Causing Orthopedic Wound Infections

Background: Despite antibiotic prophylaxis and treatment, the incidence of wound infections in orthopedic surgery is significant. Postoperative wound infection is a multifactorial process, which can be modified by several bacterial factors. Cell surface hydrophobicity of bacteria is a very important physicochemical feature, which has a great influence on the ability of bacteria to adhere to the surface of host cells or medical implants. Methods: In this study, the hydrophobic properties of thirteen bacterial strains (coagulase-negative staphylococci, Staphylococcus aureus and Pseudomonas aeruginosa) isolated from patients with postoperative deep wound infections following orthopedic procedures were determined by the salt aggregation test. Results were compared to the hydrophobicity of three Hungarian standard bacterial strains. The modifying effect of four antibiotics (cefuroxime, cefotaxime, amoxicillin combined with clavulanic acid and amikacin) – applied most often in our Department for prophylaxis and treatment of patients – were analyzed. Results: The cell surface hydrophobicity of certain strains showed considerable changes after antibiotic treatment. These alterations indicated the decrease in hydrophobicity. Supra-inhibitory concentrations (2× minimum inhibitory concentrations, MIC) of the antibiotics were able to induce more frequent alterations in hydrophobicity than sub-inhibitory (0.5× MIC) levels. Conclusions: Alterations in cell surface hydrophobicity caused by antibiotics can modify the adhesion process and thus the pathogenicity of bacterial strains. These changes should be taken into consideration in the management of proper antibiotic prophylaxis and in the treatment of orthopedic patients.

'Online' monitoring and retrospective analysis of hospital outcomes based on a scan statistic.

Statistical tests based on the scan statistic are introduced for detecting possible increases in the occurrence of hospital events. The tests use a moving window and the theoretical aspects of the tests are investigated using Markov chain theory. The main objective of this study is to provide a statistical technique to assist hospital staff in deciding whether the variation they observe is greater than usually expected under random variation. In this paper we develop the test for Poisson data and apply the theory to monitor the occurrence of orthopaedic wound infection and Methicillin-resistant Staphylo- coccus aureus colonization. We find that this method is sensitive in detecting the change in the process parameter which may not be detected by standard control chart methods. Both online and retrospective analyses are considered.

Strategy to control methicillin-resistant Staphylococcus aureus post-operative infection in orthopaedic surgery.

In the year 2000 the rate of infection after arthroplasty in our hospital was 9.75% and methicillin-resistant Staphylococcus aureus (MRSA) was the organism in 33% of the infected joints. In an attempt to overcome this unacceptable situation, we changed our prophylaxis regime over a period of 6 months. This involved modifying the precautionary measures for preventing surgical infections, active prophylaxis against any nasal reservoir of infection in joint implant patients, the control of health care personnel, the strict application of standard and contact precautions in all patients with MRSA, and the use of teicoplanin as prophylaxis during this 6-month period. This resulted in a definite decrease in the incidence of orthopaedic wound infections by MRSA, while the level of MRSA infection elsewhere in the hospital remained constant. Only one infection was detected during this 6-month trial, and this beneficial effect was maintained during the following 6 months. Since then, only sporadic new infections have been detected. Patients with arthroplasties performed during the study were followed for 12 months, and no new cases of MRSA infection were detected.

Surfactant Wound Irrigation for the Treatment of Staphylococcal Clinical Isolates

Deep wound infection involving an implanted biomaterial is a devastating complication in orthopaedic surgery. Two-thirds of such infections are monomicrobial and the most commonly isolated bacteria in human osteomyelitis and orthopaedic device infection are Staphylococcus aureus and Staphylococcus epidermidis. The purpose of the current study was to examine the effectiveness of the previously reported sequential surfactant irrigation protocol against human-isolated clinical strains of Staphylococcus aureus and Staphylococcus epidermidis in the rat model of orthopaedic implant contamination. The infectivity rate of human-isolated clinical strains of Staphylococcus aureus in a contaminated complex orthopaedic wound was reduced effectively by a sequential surfactant irrigation protocol. Also, in this model, the infectivity of Staphylococcus epidermidis was reduced by normal saline irrigation alone when compared with no irrigation. Therefore, the sequential surfactant irrigation protocol may represent an effective method of wound irrigation in monomicrobial Staphylococcus aureus orthopaedic implant contamination, and normal saline irrigation may suffice in cases of monomicrobial Staphylococcus epidermidis contamination. Additional studies are necessary to determine the clinical use of surfactant irrigation.

Comparison of clips versus sutures for routine closure of orthopaedic wounds

We recommend the use of skin clips, using an assistant to evert the wound edges, as a routine form of wound closure in most orthopaedic procedures.

Bacterial pathogens associated with infected wounds in Ogun State University Teaching Hospital, Sagamu, Nigeria

A prospective study was conducted at Ogun State University Teaching Hospital (OSUTH) between August 1999 and July 2000 in the Orthopaedics, Obstetrics and Gynaecological units to identify the bacterial pathogens associated with infected wounds as well as their antibiotic sensitivity profile. A total of 1670 patients were seen in these units, out of which 130 (7.78%) developed wound infections. There was a statistical difference (P < 0.05) between the septic wounds associated with the non-operative cases (11.9%) and those of post-operative cases (6.41%). Amongst the 186 bacterial agents isolated from all the samples examined, Klebsiella species (25.3%) accounted for the most common isolates while the least was Enterococcus faecalis (5.4%). Klebsiella species was observed to be most prevalent in the Obstetrics and Gynaecological wounds while Pseudomonas aeruginosa was the commonest in the Orthopaedic wounds. The sensitivity profile of the isolates to the commonly used antibiotics including those used as pre-operative prophylactic agents ranged between 1.67-46.8%, the range for the aminoglycosides was between 61.8-75%, while the fluoroquinolones had a range of 82.8%-89.2%. The high level of bacterial resistance to the common antibiotics in this study, re-emphasized the need to properly monitor the use of antibiotics including those used as pre-operative prophylactic agents in this country. (Af. J. of Clinical and Experimental Microbiology: 2002 3(1): 13-16)

Prevention of orthopaedic wound infections: a quality improvement project.

Using clinical practice improvement methodology, a project was undertaken to reduce the incidence of surgical wound infections following elective hip and knee replacement surgery. A team was established, key measures for improvement were identified, strategies for change were developed and an action plan was implemented. Outcomes for this project included a reduction in the rate of clean surgical wound infection for joint replacement surgery from 28% to zero. Average length of stay for total hip replacement surgery was reduced from 13.9 to 9.3 days and from 14.6 to 10.4 days for total knee replacement surgery. Guidelines for patient selection were developed along with a protocol for the management of preparation to prevent urinary tract infections. Post-discharge surveillance and a preoperative rehabilitation and exercise programme have been implemented. There is potential for wider uptake and implementation of the quality principles described herein.

Synergy between Staphylococcus aureus and Pseudomonas aeruginosa in a rat model of complex orthopaedic wounds.

We observed an interaction in animals inoculated concomitantly with Staphylococcus aureus and Pseudomonas aeruginosa during a study of the efficacy of surfactants for disinfection of orthopaedic wounds. This led us to investigate whether synergy could be demonstrated between Staphylococcus aureus and Pseudomonas aeruginosa in a rat model of complex orthopaedic wounds. A wire was implanted into the spinous process of a lumbar vertebra of Sprague-Dawley rats through a dorsal incision. Animals were divided into two groups: group one was inoculated with either Staphylococcus aureus or Pseudomonas aeruginosa, and group two received a polymicrobial inoculation with both test organisms in varying concentrations. After inoculation, the wounds were irrigated and closed. On postoperative day 14, all animals were killed and specimens from the wounds were cultured. The number of colony-forming units (CFU) of Staphylococcus aureus or Pseudomonas aeruginosa needed to cause infection in 50% of the animals (ID50) was determined with use of the Reed-Muench method. The infection rate associated with each inoculum combination was calculated, and the two groups were compared. The ID50 was 2.8 x 10(4) CFU for Staphylococcus aureus and 4.8 x 10(5) CFU for Pseudomonas aeruginosa. The combination of 10(3) CFU of Staphylococcus aureus with low concentrations (10(2), 10(3), or 10(4) CFU) of Pseudomonas aeruginosa yielded infection rates that were higher than those found with either organism alone at the same concentrations. The combination of 10(3) CFU of Staphylococcus aureus and 10(3) CFU of Pseudomonas aeruginosa yielded a 75% infection rate, which was significantly higher (p = 0.004) than that associated with 10(3) CFU of either organism alone. As the Pseudomonas aeruginosa concentration was increased (to 10(5), 10(6), and 10(7) CFU), this trend reversed, and the infection rate decreased to 33% (p = 0.004). Low concentrations of Pseudomonas aeruginosa (0 to 10(5) CFU) combined with 10(6) CFU of Staphylococcus aureus yielded infection rates ranging from 83% to 100%. At the higher concentrations of Pseudomonas aeruginosa (10(6) and 10(7) CFU), however, the infection rate again decreased, to 33% (p = 0.005). Only Staphylococcus aureus was isolated from the cultures of the specimens from the animals that had received a polymicrobial inoculum. Synergy between Staphylococcus aureus and Pseudomonas aeruginosa was demonstrated when low levels of each organism were present in the wound. As the Pseudomonas aeruginosa concentration was increased, the infection rates fell well below what would be anticipated, suggesting that low concentrations of Pseudomonas aeruginosa enhance the ability of Staphylococcus aureus to cause infection in this orthopaedic wound model. At the same time, the presence of Staphylococcus aureus in the ratios tested decreased the rate of infection by Pseudomonas aeruginosa. Staphylococcus aureus is a pathogen commonly seen in orthopaedic patients. The pathogenicity of Staphylococcus aureus was shown to be increased in the presence of anaerobic bacteria. This study is the first one that we are aware of that demonstrated synergy between Staphylococcus aureus and Pseudomonas aeruginosa, at low concentrations, in a wound model while at the same time showing that Staphylococcus aureus lowers the rate of Pseudomonas aeruginosa infection.

A comparison of prophylactic antibiotic regimens against airborne orthopaedic wound contamination

Deep infection remains a major complication of joint replacement surgery despite advances in theatre design, surgical technique and antibiotic prophylaxis. Major randomized controlled trials to determine the most effective antibiotic prophylaxis are difficult to construct and interpret. In a conventional theatre, most orthopaedic intra-operative wound contamination arrives by the airborne route. This paper describes a unique method used to compare antibiotics against airborne bacteria. Seven antibiotics were incorporated into blood agar at concentrations equivalent to serum levels. Plates were then exposed to airborne theatre bacteria using a multiple synchronous collection technique. After incubation, the percentage kill was calculated for each antibiotic. At concentrations equivalent to serum level 1h post i.v. dose, all the antibiotics proved highly effective, with kill rates>95%. Imipenem and co-amoxiclav significantly outperformed the other antibiotics with kill rates of 99.6% and 99.4%, respectively. At trough levels, the antibiotics achieved kill rates from 61% to 97.6%. Future randomized controlled trials comparing large numbers of antibiotics in the setting of an already low infection rate are inappropriate. This technique for comparing antibiotic prophylaxis in quick, inexpensive and repeatable. The superiority of imipenem is not unexpected, but of more interest is the effectiveness of co-amoxiclav over the presently favoured cefuroxime.