Bacterial Contamination Control with Sodium Hypochlorite and Jet Lavage Irrigation in a Severe Stage 4 Pelvic Pressure Injury: A Case Report.

ABSTRACT: This case report reviews the effect of combining a 250-cc bottle of standard antimicrobial, buffered sodium hypochlorite with a surgical method, low-pressure jet lavage irrigation in the outpatient setting to control difficult wound contamination. A 73-year-old man had been in treatment for over 8 years, undergoing at least 18 surgical wound debridement procedures for an extensive undermined pelvic pressure injury involving the sacrum, ischium, and greater trochanter. Cultures and polymerase chain reaction diagnostics revealed a multibacterial presence. Autofluorescent imaging (AFI) was used in 21 examinations performed after a 72-hour delay over a long weekend. The AFI contamination exceeded log 4 colony-forming units/g of tissue in all pretreatment examinations and was reduced to less than log 2 colony-forming units in 6 of 21 examinations, with the remaining 15 showing an estimated 80% or higher removal of the bacterial porphyrin "red" appearance. A total of 54 AFI examinations were performed using the combination treatment, and no adverse reactions were encountered. Treatment paradigms can be improved with a multifactorial approach.

Jet Lavage Irrigation Resolves Stage 4 Pelvic Pressure Injury Undermining.

OBJECTIVE: Patients with stage 4 pelvic pressure injuries that have large, undermined cavities are at high risk for treatment failure and often fall into the category of palliative care. This case series identified five cases where treatment had stalled, and surgical reconstructive options were limited. Jet lavage irrigation in the outpatient setting was assessed as a treatment alternative. METHODS: From an investigational review board study assessing the use of low-pressure jet lavage irrigation in the outpatient setting for chronic wounds, five patients were identified where the wound dimension increased at least 50% resulting from undermined cavities. All were considered high risk with Charlson Comorbidity Index scores of 5 or greater, and their wound healing had stalled with extended treatments of topicals and medicated dressings. A team of physical therapists irrigated these patients' wounds at the bedside with 3 L of saline 3 to 5 days per week using a special long irrigation tip to reach the depth of the undermined cavity. Digital planimetry was used to assess healing with wound size as the outcome. RESULTS: Reduction of the undermined cavities was seen early within the first 3 weeks. No patient developed wound sepsis, and bacterial contamination was determined by use of autofluorescence digital imaging. Undermining resolution occurred in four patients, and one patient with an improving wound died of COVID-19. CONCLUSIONS: This simple method offered clear benefits in each patient, but only one patient survived to complete wound healing. Patient and family satisfaction were high regarding the treatment, which created a painless, odor-free wound.

Failure of Healing in Chronic Diabetic Wounds: A Case Report.

Stalled healing in chronic wounds is a challenging problem for providers and remains multifactorial in etiology. Older adults with insulin-dependent diabetes are at very high risk. In this case report, two patients with large nonhealing wounds were considered for treatment with daily jet lavage irrigation in an attempt to remove the inflammatory products of their respective chronic wounds and eliminate the persisting biofilm bacteria. Several attempts were made to reduce treatments to two to three times per week, and negative-pressure wound therapy was initiated in both cases only to see the return of inflammation and necrosis of the wound bed. In both cases, the daily jet lavage irrigation was successful in creating a granulating wound bed that slowly healed over many months. One patient died with an open sacral pressure injury, and the other patient died 4 months after complete healing of a large heel pressure injury. The interesting observation is the necessity of daily high-intensity wound irrigation to correct the chronic infectious process. Diabetic chronic wounds in high-risk older adults are recalcitrant to standard wound treatments, and providers should consider daily jet lavage wound irrigation to deal with this problem.

How precise is computer-navigated gap assessment in TKA?

BACKGROUND: Methods to improve gap balancing in total knee arthroplasty (TKA) include the development of calibrated distractors and various devices to determine the distances of the gaps. However, few studies have validated the accuracy or precision of computer navigation to determine these measurements, especially gaps created after bone cuts have been made; doing so would be important, because optimal surgical technique relies on appropriate gap spacing. QUESTIONS/PURPOSES: We investigated the ability of a new image-free computer navigation surface registration protocol to measure gap distances in TKA. METHODS: Eight embalmed cadaveric specimens of the lower extremity were used. A surface registration software protocol defined the most distal and posterior surface points of the femoral condyles and the navigation system measured the distance of the most distal femoral condyle point to the surface of the tibia after tibial resection. The tibial resection was perpendicular to the mechanical axis and was cut with a 7° posterior slope. The navigation system measured gaps spaced by modular spacing blocks at 5° intervals from full extension to 120° of flexion. Repeatability assessed repeated measures by one surgeon. Reproducibility was assessed by performing the same measurements after complete reregistration of the computer protocol to the cadaver bones. RESULTS: The gaps measured by the computer were statistically the same as those assessed with the use of blocks with a maximum measurement error of 1 mm. Reregistration did introduce error into the measurement. The gaps changed with position of knee flexion, and there was gradual and significant stretching of the gaps with repeated measurements. CONCLUSIONS: Preliminary testing shows that computer navigation can reproduce static measurements reliably and with equal accuracy as spacer blocks. We have not demonstrated that this could be applied in a dynamic setting. CLINICAL RELEVANCE: This computer navigation system has sufficient precision to warrant investigation in the clinical setting for measuring gaps created during the surgical procedure.

Bacterial Autofluorescence Digital Imaging Guides Treatment in Stage 4 Pelvic Pressure Injuries: A Preliminary Case Series.

Pelvic pressure injuries in long-term care facilities are at high risk for undetected infection and complications from bacterial contamination and stalling of wound healing. Contemporary wound healing methods must address this problem with mechanical debridement, wound irrigation, and balanced dressings that reduce bacterial burden to enable the normal healing process. This study evaluated the impact of bacterial autofluorescence imaging to indicate wound bacterial contamination and guide treatment for severe stage 4 pelvic pressure injuries. A handheld digital imaging system was used to perform bacterial autofluorescence imaging in darkness on five elderly, high-risk, long-term care patients with advanced stage 4 pelvic pressure injuries who were being treated for significant bacterial contamination. The prescient findings of bacterial autofluorescence imaging instigated treatment strategies and enabled close monitoring of the treatment efficacy to ameliorate the bacterial contamination. Wound sepsis recurrence, adequate wound cleansing, and diagnosis of underlying periprosthetic total joint infection were confirmed with autofluorescence imaging showing regions of high bacterial load. By providing objective information at the point of care, imaging improved understanding of the bacterial infections and guided treatment strategies.

Long-term periprosthetic remodeling in THA shows structural preservation.

Although periprosthetic changes after THA have been well documented in short-term studies of less than 5 years, little is known about long-term changes. Long-term mineral changes must be evaluated against an unaffected limb control and for regional differences about a prosthesis. This study evaluated long-term periprosthetic remodeling using dual-energy x ray absorptiometry in a prospective study of patients who had noncemented THAs with a modular titanium alloy proximal-loading prosthesis. In 15 randomly selected patients, bone mineral content was measured within 15 months of surgery and then at late mean followup of 13 years. In the affected femur, there was a major decrease in periprosthetic bone mineral content in Zones 1, 2, 6, and 7 (Gruen et al.) over the course of the study. The overall decrease in Zone 7 was 39% in bone mineral content. Estimates made after controlling for the contralateral unaffected femur indicate a major loss only in Zone 7 and preservation of mineral content in Zones 3, 4, and 5 of the proximal femur. The data suggest bone remodeling maintains the overall structural integrity of the upper femoral shaft.

Six sigma analysis of minimally invasive acetabular arthroplasty: a preliminary investigation.

Minimally invasive techniques in THA may increase the difficulty of acetabular component insertion relative to the optimized position. We sought to determine the ability of eight surgeons to position an acetabular component placed using an anterior-lateral minimally invasive surgical (MIS) approach with conventional instruments or computer navigation using an optical imageless protocol compared with conventional true values determined by computed tomography (CT). We introduce a new approach, the Six Sigma process capability index, to assess outliers. Using the Six Sigma process capability index (Cp > 1.3) and the criteria of Lewinnek et al. of +/- 10 degrees for adequate precision, three-dimensional (3D) CT was capable for inclination and anteversion. Computer navigation and visual cues with conventional instrumentation were precise for anteversion but not for inclination. We conclude image-free computer navigation was not better than conventional instrumentation with the surgeons' visual cues for acetabular cup placement. Six Sigma analysis allows comparison of various methods of referencing with literature controls, and our data suggest CT referencing is the most precise method.

Comparison of tibial rotation in fixed and mobile bearing total knee arthroplasty using computer navigation.

Tibial rotation is an important aspect of knee function and can be altered after total knee arthroplasty (TKA). These alterations include decreased internal rotation with knee flexion as compared to the normal state and paradoxical external rotation with flexion. Mobile bearing total knee prostheses may allow greater unconstrained tibial rotation. I compared tibial rotation after fixed bearing or mobile bearing total knee arthroplasty in 82 patients who underwent TKA with the tibia cut first technique to ascertain any differences. Using intraoperative imageless computer navigation, measurements included the determination of tibial rotation from extension to 90 degrees flexion before and after prosthetic implantation with non-weight-bearing range of motion. I found that tibial rotation was significantly reduced after fixed bearing total knee replacement as compared to mobile bearing. In addition, the tibial position compared to the distal femur in extension was more external in fixed bearings compared to mobile bearings. Placing the fixed tibial tray with increased internal rotation could explain this difference.

Case report : femoral shaft fracture resulting from femoral tracker placement in navigated TKA.

Computer-assisted navigation is a surgical tool that may decrease malalignment outliers in TKA. With any new surgical technique, there is the possibility of unexpected complications that raise caution. We report two patients with displaced femoral fractures at optical tracker pin placement sites created for routine performance of navigated TKA. Our experience suggests single bicortical 5-mm pins placed in the femoral shaft have the added risk of creating a stress riser leading to the potential for fracture. Females may have a higher risk for this complication. We believe bicortical pin fixation in the femur or tibia no longer is indicated.

Bone morphogenetic proteins in total hip arthroplasty, osteonecrosis and trauma surgery.

This review provides an overview of the use of bone morphogenetic proteins to enhance bone healing and bone graft incorporation in difficult defects created from failed total hip arthroplasties, osteonecrosis of the femoral head and trauma. Multiple publications have demonstrated that bone morphogenetic proteins are osteoinductive in preclinical trials (i.e., animal models); however, there is controversy and limited understanding of the use of this technology in orthopedic surgical practice. The question remains as to whether they are useful in difficult fractures, nonunions and large defects created from failed total hip arthroplasty or femoral head osteonecrosis. There might be a small risk for infection by the process of introducing foreign materials in a clinical situation, but this has not yet been realized to date. In addition, these materials offer an advantage in large defects where there is not enough transplantable material available from the host. We believe that the use of these materials will become more widespread with newer carriers, minimally invasive applications and diminished commercial costs.

Metrology and Standards Needs for Some Categories of Medical Devices.

With rapid advances in meso-, micro- and nano-scale technology devices and electronics, a new generation of advanced medical devices is emerging, which promises medical treatment that is less invasive and more accurate, automated, and effective. We examined the technological and economic status of five categories of medical devices. A set of metrology needs is identified for each of these categories and suggestions are made to address them.

Computer-assisted surgery: basic concepts.

Computer-assisted surgery has been advocated as a significant enabling technology that will enhance the surgical technique of various orthopaedic procedures. The computer becomes a sophisticated measuring tool, determining the three-dimensional spatial orientation of fiducial points, which may be established by a variety of referencing methods. These fiducial points or arrays may define a bone, an instrument, or a prosthesis. Current referencing methods include using segmented computer tomograms; fluoroscopic images; ultrasound images; and imageless, direct anatomic point-picking methods. Tracking technologies use optical cameras and electromagnetic coils. Optical systems have high reliability with errors of less than 0.5 mm. Electromagnetic trackers have a similar capability, but are less reliable because of the distortion of the electromagnetic signal that may result from the complex operating room environment. Accuracy with current CT-referenced systems approximates 1 degrees or 1 mm. Other methods such as fluoroscopy or ultrasound are less precise because of difficulty related to the ability to consistently define a specific anatomic structure. Descriptive measures of outcome include standard deviation and quantification of error. Process capability indices or Six Sigma are suitable methods for comparing outcomes with computer-assisted surgery and can be generalized from various approaches.

Transepicondylar distal femoral pin placement in computer assisted surgical navigation.

UNLABELLED: The use of optical tracking systems in computer assisted surgical navigation requires the rigid fixation of a dynamic reference base to the target bone to be navigated. This report presents the results of a new approach to optical tracker fixation in the distal femur. Four embalmed cadavers were evaluated for pin placement. It was found that placement of pins from medial to lateral parallel to the transepicondylar axis placed the pins well posterior to the center of the intramedullary canal and away from neurovascular structures. Eighty-six consecutive patients underwent total knee arthroplasty using this new technique. All procedures were successful for performing a navigation-assisted total knee replacement. Obesity was not a factor, nor was there any loosening of the pin array during the procedure. There were no wound-healing problems in any patient. At one year follow-up, no patient could identify subjective symptoms related to either the medial epicondylar area or the stab wound portals. No direct neurovascular injuries were noted and no patient developed a fracture of the femur related to the pin sites. CONCLUSION: A new technique is described that facilitates pin placement for minimally invasive approaches while eliminating complications. Sagittal plane optical array orientation simplifies the surgical technique.

Comparison of fluoroscopic and imageless registration in surgical navigation of the acetabular component.

OBJECTIVE: This study compared the repeatability and reproducibility of acetabular component positioning using imageless and fluoroscopic-referenced navigation methods. METHODS: A single cadaveric pelvis had a modular acetabular component securely fixed. Cup position was evaluated using imageless and fluoroscopic registration techniques. These were compared to measurements of a coordinate measuring machine (CMM) and a validated CT scan protocol. RESULTS: The CMM-determined anatomical acetabular inclination measurement was 46.02 degrees (SD = 1.07), while the CMM-determined anatomical anteversion (pubic symphysis) was 15.79 degrees (SD = 0.41). Computed tomography revealed inclination of 42.2 degrees (SD = 0.65); anteversion with pubic tubercle referencing of 12.1 degrees (SD = 0.14); and anteversion with pubic symphysis referencing of 14.3 degrees (SD = 0.89). Evaluation of repeatability (one surgeon; n = 8) with the imageless system (pubic tubercle) revealed inclination of 41.8 degrees (SD = 0.46) and anteversion of 11.2 degrees (SD = 0.8). For the fluoroscopic system (pubic symphysis), inclination was 42.8 degrees (SD = 1.6) and anteversion was 17.6 degrees (SD = 3.1). Evaluation of reproducibility (three surgeons; n = 24) with the imageless system revealed inclination of 41.8 degrees (SD = 0.82) and anteversion of 15.2 degrees (SD = 1.06). For the fluoroscopic system, inclination was 48.5 degrees (SD = 0.9) and anteversion was 17.8 degrees (SD = 2.5). Imageless referencing of cup inclination and anteversion were found to be process capable using the Six Sigma Cp and Cpk capability indices. Fluoroscopic referencing was process capable for cup inclination but not for cup anteversion (Cp - 1.1; Cpk - 1.0). An F-test revealed significantly greater variance with fluoroscopic referenced anteversion (p < 0.002). CONCLUSIONS: Imageless referencing was process capable for computer navigation of cup placement in the ex-vivo setting. Fluoroscopic referencing for pelvic landmarks is problematic as locating points from radiographic images is difficult, especially for cup anteversion.

Extended osteotomy for periprosthetic femoral fractures in total hip arthroplasty.

Total hip arthroplasty periprosthetic fractures that involve a loose prosthesis and are located at or beyond the tip of the prosthesis are difficult to manage and have higher complication and nonunion rates. In this case report, I describe a fracture-site exposure that allows simple insertion of a long, distally fixed revision prosthesis. In an extended femoral osteotomy, the entire proximal fragment opens the upper segment in "clamshell" fashion. The proximal segment is repaired with or without femoral strut allografts and multiple cerclage wires. With this method, 7 periprosthetic fractures united successfully, and none has required further reconstruction.

Low-Contact-Stress Knee Arthroplasty: Past History or Ahead of Time?

Low-contact-stress mobile-bearing (MB) total knee arthroplasty (TKA) can rely on a long history. Its concept comprises a combination of high condylar congruency and compensatory bearing rotation to promote load sharing. However, other MB designs have become available, and critical points have been raised about the benefit of MB in general. Although there is kinematic and kinetic support for the low-contact-stress concept, there is no tribologic or clinical proof of its superiority over fixed-bearing concepts. Further study should be controlled for differences in polyethylene quality and need to provide a measure of condylar congruency to differentiate authentic low-contact-stress variants form others. [Orthopedics. 2016; 39(3):e402-e412.].

A clinical overview patellofemoral joint and application to total knee arthroplasty.

The mechanical function of the patellofemoral joint is an integral part of knee biomechanics, and remains a primary source of important clinical entities. Force transmission is the most central issue and can be described by relevant anatomical and biomechanical principles. The brief review highlights these issues focusing on recent applications to total knee arthroplasty.