Dead Space Management After Orthopaedic Trauma: Tips, Tricks, and Pitfalls

Role of STIMULAN in chronic osteomyelitis-A randomised blinded study on 95 patients comparing 3 antibiotic compositions, bead quality, forming & absorption time

Introduction

Chronic Osteomyelitis is a well-known clinical entity affecting patients holistically and presents with multiple treatment challenges. Local antibiotic delivery with biodegradable drug carriers has shown promising results.

Materials and methods

Prospective multicenter study performed at 2 centers from November 2021 to January 2023 on 95 osteomyelitis patients treated with surgical debridement & STIMULAN™ for local antibiotic delivery. Patients were randomized into 3 groups. Authors compared antibiotic combinations, bead quality, bead setting, and resorption time for calcium sulfate beads- STIMULAN™. Additionally, organisms isolated, WBC Turnover time, Hypersensitivity Reactions, Recurrence, and Revision Rates were documented.

Results

95 patients underwent surgical debridement and STIMULAN™ bead application for chronic osteomyelitis. The proximal 1/3rd tibia was commonly affected. The most common symptoms were sinus and pus discharge in 96.84 % & 86.31 % of patients respectively (p < 0.001). Staphylococcus aureus & MRSA were isolated in 37.8 % & 29.4 % of the patient's wound culture respectively. Bead setting time in Descending order was Group 3 > Group 2 > Group 1 (p < 0.001). Bead setting first in Group 1 followed by Group 3 & 2. On compression, Group-1 beads withstood maximum compression forces & had smooth even bead surfaces. On radiographs, 1/3rd bead volume in ascending order was Group 3 > Group 2 > Group 1 (p < 0.001). 2/3rd reduction in ascending order was Group 3 > Group 2 > Group 1. Complete bead absorption was earliest seen in Group 3 followed by Group 2 & Group 1 (p < 0.001). Recurrence in 2 patients (Group 2) at 6 weeks. Revision rate: 2.10 %. There were no incidences of hypersensitivity. Suture removal was done at 16 ± 2 days.

Conclusion

STIMULAN™ combination with tobramycin, vancomycin, and gentamycin is stable, and forms uniform beads with predictable drug elution & bead resorption with negligible side effects. A mixture with higher liquid content sets later, forms softer beads, and resorbs earlier.

Surgical Reconstruction of Stage 3 and 4 Pressure Injuries: A Literature Review and Proposed Algorithm from an Interprofessional Working Group

OBJECTIVE

Stage 3 and 4 pressure injuries (PIs) present an enormous societal burden with no clearly defined interventions for surgical reconstruction. The authors sought to assess, via literature review and a reflection/evaluation of their own clinical practice experience (where applicable), the current limitations to the surgical intervention of stage 3 or 4 PIs and propose an algorithm for surgical reconstruction.

METHODS

An interprofessional working group convened to review and assess the scientific literature and propose an algorithm for clinical practice. Data compiled from the literature and a comparison of institutional management were used to develop an algorithm for the surgical reconstruction of stage 3 and 4 PIs with adjunctive use of negative-pressure wound therapy and bioscaffolds.

RESULTS

Surgical reconstruction of PI has relatively high complication rates. The use of negative-pressure wound therapy as adjunctive therapy is beneficial and widespread, leading to reduced dressing change frequency. The evidence for the use of bioscaffolds both in standard wound care and as an adjunct to surgical reconstruction of PI is limited. The proposed algorithm aims to reduce complications typically seen with this patient cohort and improve patient outcomes from surgical intervention.

CONCLUSIONS

The working group has proposed a surgical algorithm for stage 3 and 4 PI reconstruction. The algorithm will be validated and refined through additional clinical research.

High Cefuroxime Concentrations and Long Elimination in an Orthopaedic Surgical Deadspace—A Microdialysis Porcine Study

Deadspace is the tissue and bony defect in a surgical wound after closure. This space is presumably poorly perfused favouring bacterial proliferation and biofilm formation. In arthroplasty surgery, an obligate deadspace surrounding the prosthesis is introduced and deadspace management, in combination with obtaining therapeutic prophylactic antibiotic concentrations, is important for limiting the risk of acquiring a periprosthetic joint infection (PJI). This study aimed to investigate cefuroxime distribution to an orthopaedic surgical deadspace in comparison with plasma and bone concentrations during two dosing intervals (8 h × 2). In a setup imitating shoulder arthroplasty surgery, but without insertion of a prosthesis, microdialysis catheters were placed for cefuroxime sampling in a deadspace in the glenohumeral joint and in cancellous bone of the scapular neck in eighteen pigs. Blood samples were collected as a reference. Cefuroxime was administered according to weight (20 mg/kg). The primary endpoint was time above the cefuroxime minimal inhibitory concentration of the free fraction of cefuroxime for Staphylococcus aureus (fT > MIC (4 μg/mL)). During the two dosing intervals, mean fT > MIC (4 μg/mL) was significantly longer in deadspace (605 min) compared with plasma (284 min) and bone (334 min). For deadspace, the mean time to reach 4 μg/mL was prolonged from the first dosing interval (8 min) to the second dosing interval (21 min), while the peak drug concentration was lower and half-life was longer in the second dosing interval. In conclusion, weight-adjusted cefuroxime fT > MIC (4 μg/mL) and elimination from the deadspace was longer in comparison to plasma and bone. Our results suggest a deadspace consolidation and a longer diffusions distance, resulting in a low cefuroxime turn-over. Based on theoretical targets, cefuroxime appears to be an appropriate prophylactic drug for the prevention of PJI.

Volumetric Evaluation of Dead Space in Ischial Pressure Injuries Using Magnetic Resonance Imaging: A Case Series

OBJECTIVE

To establish a preoperative evaluation procedure by measuring the volume of dead space using MRI in patients with ischial pressure injuries.

METHODS

Patients with spinal cord injury and ischial pressure injuries who underwent treatment between August 2016 and November 2019 were included in the study. Preoperative MRI scan was conducted on all patients. The volume estimation and three-dimensional (3D) reconstruction were performed based on MRI data using a 3D Slicer. Based on the resulting volume, a muscle flap that could fit the dead space was selected. Surgery was performed with the selected muscle flap, and a fasciocutaneous flap was added, if necessary.

RESULTS

A total of eight patients with ischial pressure injuries were included in the study. The mean patient age was 59.0 ± 11.0 years. The mean body mass index was 26.62 ± 3.89 kg/m2. The mean volume of dead space was 104.75 ± 81.05 cm3. The gracilis muscle was the most selected muscle flap and was used in four patients. In five of eight cases, a fasciocutaneous flap was used as well. The mean follow-up period was 16 months, and by that point, none of the patients evinced complications that required surgery.

CONCLUSIONS

To the authors' knowledge, this is the first report on volumetric evaluation of dead space in ischial pressure injuries. The authors believe that the 3D reconstruction process would enable adequate dead space obliteration in ischial pressure injuries. The authors propose that preoperative MRI scans in patients with ischial pressure injury should become an essential part of the process.

Comparative osteoconductivity of bone void fillers with antibiotics in a critical size bone defect model

The study aimed to evaluate the comparative osteoconductivity of three commercially available bone void fillers containing gentamicin with respect to new bone, growth, host tissue response and resorption of the implant material. Defects were created in the cancellous bone of the distal femur and proximal tibia of 12-skeletally mature sheep and filled with three commercially available bone void fillers containing gentamicin (Stimulan-G, Cerament-G, Herafill-G). Peripheral blood was taken pre-operatively and at the time of implantation, as well as at intermittent timepoints following surgery to determine systemic gentamicin levels (5-,15- and 30- minutes, 1, 2, 3, 6, 12, 24, 48- and 72-hours, 3-, 6- and 12-weeks). Decalcified, embedded samples were stained with haematoxylin and eosin (H&E) and used to assess the host tissue response and the formation of new bone in the presence of test implant materials. No adverse reactions were noted at harvest at any time points for any cancellous implantation sites with the various implant materials. Comparative microCT analysis of the Stimulan-G, Cerament-G and Herafill-G test materials revealed a similar increase in bone surface area and volume between animals implanted with Stimulan-G or Cerament-G test materials. Animals implanted with Herafill-G test materials demonstrated the lowest increases in bone volume and surface area of the test materials tested, at levels similar to the negative control sites. By 12-weeks, Stimulan-G defects were completely closed with mature bone and bone marrow whilst the Cerament-G material was still present after 12 weeks by histological examination. In conclusion, this study demonstrated differences in the bone regenerative capacity of a range of bone void fillers in an in vivo setting.

[Primary soft tissue management in open fracture]

OBJECTIVE

Debridement of soft tissue and bone in an open fracture situation to minimize infection risk and achieve primary skin closure, or to provide conditions for early soft tissue coverage.

INDICATIONS

Indications are Gustilo-Anderson grade I-III A-C open fractures.

CONTRAINDICATIONS

Contraindications are injuries requiring amputation, burns, and life-threatening injuries which make appropriate treatment temporarily impossible.

SURGICAL TECHNIQUE

Removal of gross contamination and macroscopic contaminants; debridement of the wound; complete resection of contaminated and dirty tissue; sparse step-by-step resection of contaminated or non-vital wound and bone margins until vital, bleeding tissue begins; low-pressure irrigation with isotonic irrigation fluid; diagnostic biopsies for microbiological testing; reduction of dead space by interpositioning of muscle or cement spacers loaded with local antibiotics; primary wound closure if tension-free closure possible; otherwise, if resources and knowhow permit and satisfactory clean debridement was achieved, local flap; if flap impossible, debridement not satisfactory, secondary tissue necrosis likely, potential remaining contamination or contamination with fecal matter, then vacuum-assisted closure therapy.

POSTOPERATIVE MANAGEMENT

Wound inspection on the second postoperative day, generous indication for second-look surgery after 36-48 h, wound inspection on the second postoperative day, wound inspection every other day, primary antibiotic prophylaxis with a first- or second-generation cephalosporin (e. g., cefuroxime), and adaptation of antibiotic therapy according to susceptibility screening.

RESULTS

Infection rates of 2-4.7% are reported for immediate primary wound closure in Gustilo-Anderson grade I, II, and III A open fractures. For Gustilo-Anderson grade III B, good wound healing, bony consolidation, and no need for secondary surgery was reported in 86.7% when primary wound closure was achieved.

"Iatrogenic" Segmental Defect: How I Debride High-Energy Open Tibial Fractures

High-energy, open tibial shaft fractures may result in significant comminution, bone loss, and soft tissue injuries. Early, thorough debridement of all nonviable tissue is of critical importance in treating these fractures as an inadequate initial debridement increases the risk of infection and nonunion. Large iatrogenic bone and soft tissue defects can result from debridement and will require subsequent reconstruction by both orthopaedic and plastic surgeons. Although a variety of approaches exist to address these reconstructions, successful management of bone defects remains a considerable challenge. In this article, we detail our approach to debridement and reconstruction of segmental tibial defects and provide a review on the literature on this topic.