Matthew J. Dietz

Physicians’ Ability to Manually Detect Isolated Elevations in Leg Intracompartmental Pressure

BACKGROUND Serial physical examination is recommended for patients for whom there is a high index of suspicion for compartment syndrome. This examination is more difficult when performed on an obtunded patient and relies on the sensitivity of manual palpation to detect compartment firmness-a direct manifestation of increased intracompartmental pressure. This study was performed to establish the sensitivity of manual palpation for detecting critical pressure elevations in the leg compartments most frequently involved in clinical compartment syndrome. METHODS Reproducible, sustained elevation of intracompartmental pressure was established in fresh cadaver leg specimens. Pressures tested included 20 and 40 mm Hg (negative controls) and 60 and 80 mm Hg (considered to be consistent with a compartment syndrome). Each leg served as an internal control, with three compartments having a noncritical pressure elevation. Orthopaedic residents and faculty were individually invited to manually palpate the leg with a known compartment pressure and to answer the following questions: (1) Is there a compartment syndrome? (2) In which compartment or compartments do you believe the pressure is elevated, if at all? (3) Describe your examination findings as soft, compressible, or firm. RESULTS When a true-positive result was considered to be the correct detection of an elevation of intracompartmental pressures and correct identification of the compartment with the elevated pressure, the sensitivity of manual palpation was 24%, the specificity was 55%, the positive predictive value was 19%, and the negative predictive value was 63%. With increasing intracompartmental pressure, fasciotomy was recommended with a higher frequency (19% when the pressure was 20 mm Hg, 28% when it was 40 mm Hg, 50% when it was 60 mm Hg, and 60% when it was 80 mm Hg). When a true-positive result of manual palpation was considered to be an appropriate recommendation of fasciotomy, regardless of the ability of the examiner to correctly localize the compartment with the critical pressure elevation, the sensitivity was 54%, the specificity was 76%, the positive predictive value was 70%, and the negative predictive value was 63%. CONCLUSIONS Manual detection of compartment firmness associated with critical elevations in intracompartmental pressure is poor.

Evaluation of local MCP-1 and IL-12 nanocoatings for infection prevention in open fractures

The increasing incidence of bacterial infection and the appearance of Staphylococcus aureus (S. aureus) strains that are resistant to commonly used antibiotics has made it important to develop non‐antibiotic approaches for infection prevention. The aim of this study was to develop local monocyte chemoattractant protein‐1 (MCP‐1) and interleukin‐12 p70 (IL‐12 p70) therapies to prevent S. aureus infection by enhancing the recruitment and activation of macrophages, which are believed to play an important role in infection prevention as the first line of defense against invading pathogens. Nanocoating systems for MCP‐1 and IL‐12 p70 deliveries were prepared, and their release characteristics desirable for infection prevention in open fractures were explored. Local MCP‐1 therapy reduced S. aureus infection and influenced white blood cell populations, and local IL‐12 p70 treatment had a more profound effect on preventing S. aureus infection. No synergistic relationship in decreasing S. aureus infection was observed when MCP‐1 and IL‐12 p70 treatments were combined. This reported new approach may reduce antibiotic use and antibiotic resistance.

Smartphone assessment of knee flexion compared to radiographic standards

BACKGROUND Measuring knee range of motion (ROM) is an important assessment for the outcomes of total knee arthroplasty. Recent technological advances have led to the development and use of accelerometer-based smartphone applications to measure knee ROM. The purpose of this study was to develop, standardize, and validate methods of utilizing smartphone accelerometer technology compared to radiographic standards, visual estimation, and goniometric evaluation. METHODS Participants used visual estimation, a long-arm goniometer, and a smartphone accelerometer to determine range of motion of a cadaveric lower extremity; these results were compared to radiographs taken at the same angles. RESULTS The optimal smartphone position was determined to be on top of the leg at the distal femur and proximal tibia location. Between methods, it was found that the smartphone and goniometer were comparably reliable in measuring knee flexion (ICC=0.94; 95% CI: 0.91-0.96). Visual estimation was found to be the least reliable method of measurement. CONCLUSIONS The results suggested that the smartphone accelerometer was non-inferior when compared to the other measurement techniques, demonstrated similar deviations from radiographic standards, and did not appear to be influenced by the person performing the measurements or the girth of the extremity.

Best practices for centers of excellence in addressing periprosthetic joint infection.

Periprosthetic joint infection is a rare and devastating complication. Management of this complication often requires a multidisciplinary approach similar to that used for the care of patients with cancer. Several studies have reported better outcomes following total joint arthroplasties performed at specialized hospitals than those performed at general hospitals. Specialized institutions use care pathways that aid the multidisciplinary team in decision making. During the recent Musculoskeletal Infection symposium, specific issues were discussed with regard to the treatment of periprosthetic joint infection, including medical optimization, systematic approaches to infection management, and the importance of establishing registries to aid in the creation of Centers of Excellence. A Center of Excellence in periprosthetic infection could provide better overall outcomes with lower financial, physical, and emotional costs to patients.

Transfer of patient care during two-stage exchange for periprosthetic joint infection leads to inferior outcomes.

The two-stage exchange algorithm is the gold standard for managing chronic periprosthetic joint infection (PJI); this study evaluated the impact of having the stages performed at different institutions. Patients with a chronically infected total joint arthroplasty (hip or knee) with initial resection at an outside hospital and subsequent care at our institution (transferred group) were identified then matched with a similar cohort that received both stages at our institution (continuous group). Eighteen patients (transferred group) were compared to 36 matched controls. There were significantly lower rates of successful reimplantation and retention, longer duration of treatment and more procedures in the transferred group compared to the continuous group. Patients transferred during their care for chronic PJI underwent more surgeries, longer treatment times, and less favorable outcomes.

All-Terrain Vehicle-Related Orthopaedic Trauma in North Central West Virginia: An 8-Year Review of a Level I Trauma Center

Objectives: All-terrain vehicle (ATV)-related trauma is increasing nationally. This study highlights the demographics, mechanisms, and associated orthopaedic injuries for ATV-related traumas that presented to our Level I trauma center over an 8-year period and addresses the effects of statewide legislation on injury occurrences. Design: Retrospective. Setting: Level I trauma center in West Virginia. Patients: Those presenting to a Level I trauma center with ATV-related injuries between January 2000 and June 2007. Main Outcomes: We reviewed data available for demographics, substance abuse, helmet use, length of stay, discharge disposition, injury mechanism and severity, anatomic location of injuries, and orthopaedic injuries. Results: In 2000, 72 individuals presented with ATV-related injuries; this number rose significantly each year to 234 individuals in 2006. Of the 1234 patients over 8 years, 79% were male and 95% were white. The average age was 30 years (range, 1–87 years) with 22% of those injured being aged 16 years or younger. Only 27% of the riders were helmeted. There were 647 (52%) patients who sustained orthopaedic injuries (defined as fractures or dislocations). There was no significant decrease in injury occurrence after the implementation of statewide ATV-related legislation in 2004. Conclusions: This trauma center is in a unique position to highlight a national problem. Over half (52%) of the patients had an orthopaedic injury defined as a fracture or dislocation. Before measures can be implemented to effect change, we must first be aware of the exact nature and spectrum of injuries associated with ATV use.

Topical Adjuvants Incompletely Remove Adherent Staphylococcus aureus from Implant Materials

Adjuvant treatments including Betadine, Dakins solution (sodium hypochlorite), or hydrogen peroxide (H2O2) have been attempted to eradicate prosthetic joint infection caused by biofilm or intracellular bacteria. The purpose of this study was to evaluate the in vitro abilities of chemical adjuvants to decrease Staphylococcus aureus (S. aureus) biofilm presence on orthopaedic implant grade materials, including titanium, stainless steel, and cobalt chrome. S. aureus biofilms were grown for 48 h and evaluated for baseline colony forming units/centimeter squared (CFU/cm2) and compared to treatments with Betadine, Dakins solution, H2O2, or 1% chlorine dioxide (ClO2). Control discs (n = 18) across all metals had an average of 4.2 × 107 CFU/cm2. All treatments had statistically significant reductions in CFU/cm2 when compared to respective control discs (p < 0.05). For all metals combined, the most efficacious treatments were Betadine and H2O2, with an average 98% and 97% CFU/cm2 reduction, respectively. There were no significant differences between reductions seen with Betadine and H2O2, but both groups had statistically greater reductions than Dakins solution and ClO2. There was no change in antibiotic resistance patterns after treatment. Analysis of S. aureus biofilms demonstrated a statistically significant reduction in biofilm after a five‐minute treatment with the modalities, with an average two log reduction in CFU/cm2. Statement of clinical significance: While statistically significant reductions in CFU/cm2 were accomplished with chemical adjuvant treatments, the overall concentration of bacteria never fell below 105 CFU/cm2, leading to questionable clinical significance. Further techniques to eradicate biofilm should be investigated.

Novel technique for removal of a broken intracortical screw during THA.

Most reports regarding hardware removal involve the violation of the cortex to allow a specialized to tool to extract a retained fragment. This leaves large, unfilled screw holes that act as stress risers for months postoperatively. This article describes a novel technique to remove a retained intracortical screw fragment during total hip arthroplasty. Conversion of an intertrochanteric osteotomy to a total hip arthroplasty can be made more difficult by anatomical changes to the femur and retained hardware. Direct access to the intramedullary canal during total hip arthroplasty allowed for the safe removal of a retained intracortical screw using this technique.

Suppressive Oral Antibiotics in Orthopaedic Prosthetic Joint Infections

In orthopaedics, the use of oral suppressive antibiotics for the treatment of implant related infection was a treatment regimen that had been reserved only for patients who were unable to tolerate surgery. Recent literature has begun to demonstrate the benefits of utilizing suppressive antibiotics as an adjuvant treatment in addition to surgical debridement. The use of oral suppressive antibiotics carries with it inherent hurdles regarding dosing, tolerance, side effects, and cost that need to be considered. The purpose of this review is to act as a guide for orthopaedic surgeons and medical providers to allow them to safely utilize oral suppressive antibiotic regimens as part of their treatment algorithm.

Biomaterials in Total Joint Arthroplasty

Total joint arthroplasties have increased significantly in number over the past several decades and appear to continue to increase exponentially in correlation with the demands of an aging population. The multifaceted approach to providing patients with a lasting implant is divided among the patient characteristics, surgical skills, and the biomaterials of the implant. The following chapter reviews the most commonly used biomaterials for total joint arthroplasty, their properties, their interaction with other implants, and the current progress in improving each material for greater stability, sterility, and survivability. This chapter also highlights the clinical relevance of these materials by presenting several case reports of failures of varying materials.