Richelle C. Takemoto

Prevalence of Staphylococcus aureus colonization in orthopaedic surgeons and their patients: a prospective cohort controlled study.

BACKGROUND Methicillin-resistant Staphylococcus aureus and methicillin-sensitive Staphylococcus aureus surgical site infections are an increasing health problem in the United States. To date, no study, as far as we know, has evaluated the prevalence of Staphylococcus aureus colonization in orthopaedic surgeons. The purpose of our study was to assess the prevalence of methicillin-resistant Staphylococcus aureus and methicillin-sensitive Staphylococcus aureus colonization in orthopaedic surgery attending surgeons and residents at our institution compared with that in our high-risk patients. METHODS We performed nasal swab cultures in seventy-four orthopaedic attending surgeons and sixty-one orthopaedic surgery residents at our institution, screening for methicillin-resistant Staphylococcus aureus and methicillin-sensitive Staphylococcus aureus. We compared these results with a prospective database of nasal cultures of patients undergoing joint replacement and spine surgery. RESULTS A total of 135 physicians were screened. Of those physicians, 1.5% were positive for methicillin-resistant Staphylococcus aureus and 35.7% were positive for methicillin-sensitive Staphylococcus aureus. None of the sixty-one residents were positive for methicillin-resistant Staphylococcus aureus. However, 59% were positive for methicillin-sensitive Staphylococcus aureus. Of the seventy-four attending surgeons, 2.7% were positive for methicillin-resistant Staphylococcus aureus and 23.3%, for methicillin-sensitive Staphylococcus aureus. Previous studies at our institution have demonstrated a 2.17% prevalence of nasal carriage of methicillin-resistant Staphylococcus aureus and an 18% rate of methicillin-sensitive Staphylococcus aureus in high-risk patients. Thus, no difference was found between the prevalence of methicillin-resistant Staphylococcus aureus in residents or attending surgeons and that in the high-risk patients. However, the prevalence of methicillin-sensitive Staphylococcus aureus colonization in the surgeons (35.7%) was significantly higher than that in the high-risk patient group (18%) (p < 0.01). CONCLUSIONS At a major teaching hospital, a higher prevalence of methicillin-sensitive Staphylococcus aureus colonization was found among attending and resident orthopaedic surgeons compared with a high-risk patient group, but the prevalence of methicillin-resistant Staphylococcus aureus colonization was similar.Background: Methicillin-resistant Staphylococcus aureus and methicillin-sensitive Staphylococcus aureus surgical site infections are an increasing health problem in the United States. To date, no study, as far as we know, has evaluated the prevalence of Staphylococcus aureus colonization in orthopaedic surgeons. The purpose of our study was to assess the prevalence of methicillin-resistant Staphylococcus aureus and methicillin-sensitive Staphylococcus aureus colonization in orthopaedic surgery attending surgeons and residents at our institution compared with that in our high-risk patients. Methods: We performed nasal swab cultures in seventy-four orthopaedic attending surgeons and sixty-one orthopaedic surgery residents at our institution, screening for methicillin-resistant Staphylococcus aureus and methicillin-sensitive Staphylococcus aureus. We compared these results with a prospective database of nasal cultures of patients undergoing joint replacement and spine surgery. Results: A total of 135 physicians were screened. Of those physicians, 1.5% were positive for methicillin-resistant Staphylococcus aureus and 35.7% were positive for methicillin-sensitive Staphylococcus aureus. None of the sixty-one residents were positive for methicillin-resistant Staphylococcus aureus. However, 59% were positive for methicillin-sensitive Staphylococcus aureus. Of the seventy-four attending surgeons, 2.7% were positive for methicillin-resistant Staphylococcus aureus and 23.3%, for methicillin-sensitive Staphylococcus aureus. Previous studies at our institution have demonstrated a 2.17% prevalence of nasal carriage of methicillin-resistant Staphylococcus aureus and an 18% rate of methicillin-sensitive Staphylococcus aureus in high-risk patients. Thus, no difference was found between the prevalence of methicillin-resistant Staphylococcus aureus in residents or attending surgeons and that in the high-risk patients. However, the prevalence of methicillin-sensitive Staphylococcus aureus colonization in the surgeons (35.7%) was significantly higher than that in the high-risk patient group (18%) (p Conclusions: At a major teaching hospital, a higher prevalence of methicillin-sensitive Staphylococcus aureus colonization was found among attending and resident orthopaedic surgeons compared with a high-risk patient group, but the prevalence of methicillin-resistant Staphylococcus aureus colonization was similar.

Evaluation of femoral strains with cementless proximal-fill femoral implants of varied stem length

BACKGROUND The design intent of proximally-filling lateral flare femoral stems is to load the endosteal surface of the proximal femur both laterally and medially, to achieve normal bone strains. However, the long stem can contact the femoral cortex and may offload the proximal region to some extent. Therefore, in this study, we sought to determine if reducing the stem length, would result in physiologic strain patterns. METHODS Using the PhotoStress® method we analyzed 13 femurs intact and with three different stem length implants: stemless, ultra-short and short. The test rig loaded the femoral head by simulating the mid-stance single leg support phase of gait with the ilio-tibial band and the hip abductor forces. The strain distribution with each stem length implant was then compared to the intact strain distribution to determine which was most similar. FINDINGS As the stem length increased the femurs exhibited a typical pattern of reduced proximal strain and increased distal strain. However, there was some variation in this pattern indicating that the exact stem position and the location of its interaction with the endosteal surface of bone was not the same in each femur. INTERPRETATION The stemless design provided the best match compared to the native femur and therefore has the greatest potential to address the shortcomings of a stemmed femoral implant. However, the ultra-short implant also exhibited a strain distribution that closely emulated the intact femur, and may represent the best option as there are still several questions pertaining to stability and alignment of a stemless implant.

Treatment of Two-Part Proximal Humerus Fractures: Intramedullary Nail Compared to Locked Plating

BackgroundTwo-part proximal humerus fractures are common orthopedic injuries for which surgical intervention is often indicated. Choosing a fixation device remains a topic of debate.PurposeThe purpose of this study is to compare two methods of fixation for two-part proximal humerus fractures, locking plate (LP) with screws versus intramedullary nailing (IMN), with respect to alignment, healing, patient outcomes, and complications. To our knowledge, a direct comparison of these two devices in treating two-part proximal humerus fractures has never before been studied. We hope that our results will help surgeons assess the utility of LP versus IMN.MethodsA retrospective chart review was performed on 24 cases of displaced two-part surgical neck fractures of the humerus. Twelve shoulders were treated using IMN fixation and 12 others were fixated with LP. Data collected included sociodemographic, operative details, and postoperative care and function.ResultsRadiographic comparison of fixation demonstrated an average neck-shaft angle of 124° and 120° in the IMN group and LP group, respectively. Adjusted postoperative 6-month follow-up range of motion was 134° of forward elevation in the IMN group and 141 in the LP group. The differences in range of motion and in complication rates were not found to be significant.ConclusionsOur results suggest that either LP fixation or IMN fixation for a two-part proximal humerus fracture provides acceptable fixation and results in a similar range of shoulder motion. Although complication rates were low and insignificant between the two groups, a trend toward increased complications in the IMN group is noted.

Quantitative assessment of the bone morphogenetic protein expression from alternate bone graft harvesting sites.

Objective: Bone morphogenetic proteins (BMPs) play important roles in the stimulation of osteogenesis and osteoinduction during bone fracture healing and their expression levels may be important for bone graft efficacy. The objective of this study was to determine if there are variations in the expression of BMPs and their receptors in various bone graft harvesting sites. We analyzed autogenous marrow aspirates obtained from three different graft sites for the mRNA levels of BMPs and their receptors. Methods: Using real-time polymerase chain reaction, we analyzed the mRNA levels of BMPs and their receptors in autogenous bone marrow aspirates obtained from three different bone graft sites of 10 different human subjects. Collection of autogenous bone marrow from the iliac crest, the proximal humerus, and the proximal tibia was performed using standard sterile techniques in the operating room as part of surgery to treat an established fracture nonunion. Results: The mRNA levels of BMP-2 and BMP-5 were the highest in the bone marrow aspirates from the three different sites, whereas the mRNA levels of the other osteoinductive BMPs (BMP-4, -5, -6, -7, -8, and -9) were lower. The mRNA levels of BMP-3, an inhibitor of osteogenesis, were the lowest in the bone marrow aspirates of all three different sites. There were no statistical significant differences in the mRNA levels of any of the BMPs or their receptors investigated in this study in the bone marrow of the three different sites. Conclusion: Because no statistical significant differences in the mRNA levels of the BMPs and their receptors were detected in the bone marrow aspirates from the three different sites, our findings suggest that potential differences of various graft sites in the augmentation of bone healing does not result from different expression levels of BMPs.

Who is lost to followup?: a study of patients with distal radius fractures.

Distal radius fractures are the most common upper extremity fracture, representing one-sixth of all fractures treated in emergency departments nationwide. Beyond the initial reduction and immobilization of these fractures, providing proper followup to ensure maintenance of the reduction and identify complications is necessary for optimal recovery of forearm and wrist functions. We sought to identify the clinical and demographic factors that characterize patients with distal radius fractures who do not return for followup and to assess the underlying causes for their poor followup rates. Compared with patients who were compliant with followup, those lost to followup had lower Physical and Mental Health scores on the SF-36 forms, more often were treated nonoperatively, and more likely had not surpassed secondary education. However, we found no difference between these two groups based on age, gender, mechanism of injury, marital status, or hand dominance. Early identification of patients who potentially are noncompliant can result in additional measures being taken to ensure the patient’s return to the treating hospital and physicians. This in turn will prevent complications attributable to lack of followup and allow more accurate assessment of results, thereby improving patient outcomes.

Midfoot fusion: a biomechanical comparison of plantar planting vs intramedullary screws.

Background: Numerous reconstructive techniques for midfoot collapse secondary to Charcot neuroarthropathy have been described, but few have been studied biomechanically. The purpose of this study was to biomechanically compare 2 of the most common techniques. Methods: Seven paired below-knee specimens were amputated through the talonavicular and calcaneocuboid joints. The nonligamentous soft tissue was stripped proximal to the metatarsal heads and disarticulated through the tarsometatarsal (TMT) joints. For each paired specimen, the TMT joints were fused by plantar plating or intramedullary screw fixation for the contralateral side. The specimens were mounted, loaded, and cycled, and fixation stiffness was determined. Load versus displacement graphs were used to calculate overall construct stiffness, and data were analyzed by Student t tests. Results: There was no failure of hardware. All failures were at the bone-implant interface. Failure was either by screw pull-out, bone fracture, or a combination of the two. There were no notable differences between the 2 fixation techniques with respect to stiffness or loads to failure. There was a trend toward a stiffer first TMT construct using the plantar plating method. Five of the 7 screw fixations failed by pullout of the base of the first metatarsal and the other 2 by pullout of screws from all MT bases. Seven of the 7 plantar plate fixations failed by separation of the fifth to third MT bases originating at the fifth, and 3 showed fracture of the fifth metatarsal base. Conclusions: There was no notable biomechanical difference between the 2 techniques. There was a trend toward a stiffer construct at the first TMT with plantar plating. Clinical Relevance: This study biomechanically analyzes two common Charcot midfoot reconstruction techniques and highlights the need for further study of both techniques and combinations of these techniques.

Appropriateness of Twenty-four-Hour Antibiotic Prophylaxis After Spinal Surgery in Which a Drain Is Utilized: A Prospective Randomized Study.

BACKGROUND Wound drains that are left in place for a prolonged period of time have a higher rate of bacterial contamination. Following spinal surgery, a drain is often left in place for a longer period of time if it maintains a high output. Given the major consequences of an infection following spinal surgery and the lack of data with regard to the use of antibiotics and drains, we performed a study of patients with a drain following spinal surgery to compare infection rates between those who were treated with antibiotics for twenty-four hours and those who received antibiotics for the duration for which the drain was in place. METHODS We performed a prospective randomized trial of 314 patients who underwent multilevel thoracolumbar spinal surgery followed by use of a postoperative drain. The patients were randomized into two groups, one of which received perioperative antibiotics for twenty-four hours (twenty-four-hour group) and the other of which received antibiotics for the duration that the drain was in place (drain-duration group). Data collected included demographic characteristics, medical comorbidities, type of spinal surgery, and surgical site infection. RESULTS Twenty-one (12.4%) of the 170 patients in the twenty-four-hour group and nineteen (13.2%) of the 144 in the drain-duration group developed a surgical site infection (p = 0.48). There were no significant differences between the twenty-four-hour and drain-duration groups with respect to demographic characteristics (except for the American Society of Anesthesiologists [ASA] classification), operative time, type of surgery, drain output, or length of hospital stay. CONCLUSIONS Continuing perioperative administration of antibiotics for the entire duration that a drain is in place after spinal surgery did not decrease the rate of surgical site infections.

No Advantage to rhBMP-2 in Addition to Autogenous Graft for Fracture Nonunion

Bone morphogenetic proteins are a necessary component of the fracture healing cascade. Few studies have delineated the efficacy of iliac crest bone graft and recombinant human bone morphogenetic protein 2 (rhBMP-2), especially, in comparison with the gold standard treatment of nonunion, which is autogenous bone graft alone. This study compared the outcome of patients with fracture nonunion treated with autogenous bone graft plus rhBMP-2 adjuvant vs patients treated with autogenous bone graft alone. A total of 118 consecutive patients who were to undergo long bone nonunion surgery with autogenous bone graft (50) or autogenous bone graft plus rhBMP-2 (68) were identified. Surgical intervention included either harvested iliac autogenous bone graft or autogenous bone graft plus 1.5 mg/mL of rhBMP-2 placed in and around the site of nonunion. No differences were found in the distribution of nonunion sites included within each group. Twelve-month follow-up was obtained on 100 of 118 patients (84.7%). Analyses of demographic characteristics (including tobacco), medical comorbidities, previous surgeries, and nonunion type (atrophic vs hypertrophic) did not differ. Postoperative complication rates did not differ. The percentage of patients who progressed to union did not differ. Mean time to union in the autogenous bone graft plus rhBMP-2 group was 6.6 months (±3.9) vs 5.4 (±2.7) months in the autogenous bone graft-only group (P=.06). Rates of revision (16.2% for rhBMP-2 plus autogenous bone graft vs 8% for autogenous bone graft) did not differ statistically (P=.19), nor did 12-month scores of pain and functional assessment. Although rhBMP-2 is a safe adjuvant, there was no benefit seen when rhBMP-2 was added to autogenous bone graft in the treatment of long bone nonunion. Given its high cost, rhBMP-2 should be reconsidered as an aid to autogenous bone graft in the treatment of nonunion.

Atypical femur fractures.

Summary: Osteoporosis (OP) results from an imbalance between bone production and absorption that results in decreased bone mass and microstructural deterioration of the bone trabeculae, leading to diminished bone quality and fragility fractures. It is synonymous with decreased bone strength and affects millions of people worldwide. The most commonly prescribed drugs for the treatment of OP are the bisphosphonates (BPs). Long-term BP use may be associated with stress fractures of the subtrochanteric and shaft regions of the femur known as atypical femur fractures (AFFs). Although AFFs can be devastating, BPs have decreased the number of low-energy hip fractures and the number of vertebral and nonvertebral fractures that occur each year. Many trials and population-based studies have assessed the association between AFF and BP, and several studies have attempted to establish AFFs true incidence. The authors will summarize a few of the major studies and discuss their strengths and limitations. The findings of an association between BPs and AFFs have been variable and may reflect sample selection and measurement bias. AFFs are uncommon; the increase in risk associated with BP use is very small and does not outweigh the benefit of fracture prevention in patients with OP. Evidence for the efficacy of BPs for the prevention of fractures in postmenopausal women with OP is very strong, and the current clinical practice of using BPs as first-line therapy for these patients should be continued. Further information is required to determine the appropriate duration and time of discontinuation of BP therapy.

Analysis of Postoperative Thoracolumbar Spine Infections in a Prospective Randomized Controlled Trial Using the Centers for Disease Control Surgical Site Infection Criteria

Introduction Wound infections following spinal surgery place a high toll on both the patient and the healthcare system. Although several large series studies have examined the incidence and distribution of spinal wound infection, the applicability of these studies varies greatly since nearly every study is either retrospective and/or lacks standard inclusion criteria for defining surgical site infection. To address this void, we present results from prospectively gathered thoracolumbar spine surgery data for which the Centers for Disease Control (CDC) criteria were stringently applied to define a surgical site infection (SSI). Methods A prospective randomized trial of 314 patients who underwent multilevel thoracolumbar spinal surgery with instrumentation followed by postoperative drain placement was completed (Takemoto et al., 2015). The trial consisted of two antibiotic arms: one for 24-hours, and the other for the duration of the drain; no differences were found between the arms. All infections meeting CDC criteria for SSI were included. Results A total of 40 infections met CDC criteria for SSI, for an overall incidence of 12.7%. Of these, 20 (50%) were culture-positive. The most common organism was Staphylococcus aureus (4 total: methicillin-sensitive=2; methicillin-resistant=2), followed by coagulase-negative Staphylococcus (3 cases), Propionibacterium acnes and Escherichia coli (2 cases each). Six infections grew multiple organisms, most commonly involving coagulase-negative staphylococcus and enterococcus. Conclusions Our findings indicate that thoracolumbar SSI occurs at the higher end of the range cited in the literature (2-13%), which is largely based on retrospective data not subjected to the inclusivity of SSI as defined by the CDC. The three most common organisms in our analysis (S. aureus, P. acnes, E. coli) are consistent with previous reports. Staphylococcus aureus continues to be the most common causative organism and continued vigilance and searching for preventive measures need to be a high priority. This study provides Level I evidence.