Results of vancomycin-impregnated cancellous bone grafting for infected tibial nonunion

[Reconstruction of a metadiaphyseal bone defect after open comminuted fracture of the proximal femur using a modified Masquelet technique]

The reconstruction of segmental bone defects after surgical treatment of infected delayed unions as well as nonunions, places the highest demands on the surgical technical implementation. After treating the fracture-related infection, guaranteeing biomechanical stability is crucial for the success of the treatment. The presented case describes the successful treatment of an infected delayed union after an open metadiaphyseal comminuted fracture of the proximal femur using a modified Masquelet technique. A solid allogeneic bone graft in combination with autologous cancellous bone were inserted into a 7 cm subtrochanteric defect zone and stabilized with a combined plate and nail osteosynthesis.

Vancomycin Flushing Syndrome After the Use of Vancomycin-Impregnated Bone Graft During Spine Surgery: A Case Report

CASE

Intrawound vancomycin in spine surgery is a common clinical practice. We report a case of a 14-year-old adolescent girl undergoing surgery for scoliosis correction who developed features of vancomycin flushing syndrome after the use of vancomycin-impregnated bone graft. After resuscitation, she was extubated and had an uneventful postoperative recovery. At 1-year follow-up, she is back to her routine without any sequelae of the intraoperative event.

CONCLUSION

The use of intrawound vancomycin can result in life-threatening reactions. With the increase in its use, the anesthetist and the surgeon must be aware of such complications.

Does local vancomycin powder impregnated with autogenous bone graft and bone substitute decrease the risk of deep surgical site infection in degenerative lumbar spine fusion surgery?—An ambispective study

Background

Deep surgical site infection (DSSI) is one of the most challenging complications in lumbar fusion surgery. Few investigations examined the effect of vancomycin powder mixed with autogenic bone graft (ABG) and bone substitutes on preventing DSSI in degenerative lumbar fusion surgeries as well as any interference with bony fusion. The aim of the study was to investigate the effects of ABG along with bone substitutes as a local vancomycin delivery system on preventing DSSI in lumbar instrumented fusion and compared with those who did not use vancomycin powder.

Methods

From January, 2015 through December, 2015, a one-year prospective study using vancomycin powder mixed with ABG and bone substitute for degenerative lumbar fusion surgeries as vancomycin (V) group, 1 gm vancomycin for 2 and 3-level, and 2 gm for more than 3-level instrumentation. From December, 2013 through December 2014, patients received degenerative lumbar fusion surgeries without using vancomycin before the vancomycin protocol were retrospectively enrolled as non-vancomycin (NV) group. Vancomycin concentration was checked at post-operative days 1 and 3 for both the serum and drainage. Patients’ demographic data, microbiology reports, fusion status and functional outcomes were evaluated.

Results

One hundred and ten patients were enrolled prospectively in the V group, and 86 for the NV group. After an average 41 months follow-up (range, 36–54), 3 patients (3.48%) developed postoperative DSSIs in the NV group, thereby requiring revision surgeries and parenteral antibiotics treatment versus no DSSIs (0%, 0/100) in the V group. (p = 0.048). The postoperative serum vancomycin levels were undetectable and no vancomycin related side effects was encountered. The mean vancomycin concentration of drainage at postoperative days 1 and 3 were 517.96 ± 174.4 and 220.14 ± 102.3 μg/mL, respectively. At final follow-up, there was no statistical difference observed in terms of clinical and radiologic outcomes.

Conclusions

Our vancomycin protocol may reduce the incidence of DSSI in degenerative lumbar fusion surgery without affecting bony fusion.

Level of Evidence

Level III ambispective comparative study.

Treatment of Posttraumatic Tibial Diaphyseal Bone Defects: A Systematic Review and Meta-Analysis

OBJECTIVE

To describe evidenced-based treatment options for patients who sustained trauma and/or posttraumatic osteomyelitis of the tibia resulting in diaphyseal bone defects and to compare outcomes between patients treated with nonvascularized bone grafts (NBGs), bone transport (BT), or vascularized bone grafts (VBGs).

DATA SOURCE

The Preferred Reporting Items for Systematic Review and Meta-Analyses of individual participant data and Cochrane guidelines were followed. PubMed, EMBASE, Cochrane Library, Web of Science, Scopus, and CINAHL were searched from inception to June 2020.

STUDY SELECTION

Patients who were ≥18 years, had sustained trauma to the tibia resulting in fracture and/or osteomyelitis with measurable diaphyseal bone defects, and were treated by interventions such as NBGs, BT, or VBGs were eligible. Excluded studies were non-English, reviews, nonreviewed literature, cadavers, animals, unavailable full texts, nondiaphyseal defects, atrophic nonunions, malignancy, and replantations.

DATA EXTRACTION

A total of 108 studies were included with 826 patients. Two reviewers systematically/independently screened titles/abstracts, followed by full texts to ensure quality, accuracy, and consensus among authors for inclusion/exclusion of studies. A third reviewer addressed disagreements if investigators were unable to reach a consensus. Studies were quality assessed using "Methodological Quality and Synthesis of Case Series and Case Reports".

DATA SYNTHESIS

Analyses were performed with IBM SPSS version 25.0 (IBM Corporation, Armonk, NY) and G*Power3.1.9.2.

CONCLUSIONS

NBGs may be considered first line for trauma defect sizes ≤ 10 cm or posttraumatic osteomyelitis defect sizes <5 cm. BT may be considered first line for posttraumatic osteomyelitis defect sizes <5 cm. VBGs may be considered first line for trauma and posttraumatic osteomyelitis defect sizes ≥5 cm.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Clinical study on orthopaedic treatment of chronic osteomyelitis with soft tissue defect in adults

To investigate the clinical application value of different flap transfer and repair techniques in adult patients with chronic osteomyelitis of limbs complicated with soft tissue defects. According to the characteristics and defects of 21 cases, different plastic surgery was applied, including debridement, negative pressure device, and tissue flap to cover wound. Among 21 cases of chronic osteomyelitis complicated with local soft tissue defect, 15 patients were repaired with sural neurotrophic musculocutaneous flap transfer, 2 patients were repaired with medial plantar skin flap transfer, 2 patients were repaired with ilioinguinal skin flap transfer, 1 patient was repaired with z‐forming wound, and 1 patient was repaired with soleus muscle flap combined with full‐thickness skin graft. All the 21 patients underwent bone cement implantation after dead bone osteotomy. Among them, 19 patients underwent bone cement replacement with 3D prosthesis within 6 months to 1 year after surgery, and 2 patients carried bone cement for a long time. Early intervention, thorough debridement, removal of necrotic or infection, and then selecting the appropriate wound skin flap coverage are important means of guarantee slow osteomyelitis wound healing and for providing a possible way to permanent prosthesis implantation subsequently.

Single stage reconstruction of segmental skeletal defects by bone graft in a synthetic membrane

INTRODUCTION

Segmental skeletal defects are very difficult to treat. The current options are lengthy procedures, require more than one surgery and plagued with many complications. The aim of this study is to assess the results of bone graft in surgicel as a synthetic membrane for reconstruction of segmental skeletal defects in one stage surgery.

METHODS

Fourteen patients with segmental skeletal defects were included in the study. The ages ranged from 20 to 54 years with an average of 32 years. The defects were due to high energy trauma in all cases. The size of the defects ranged from 5 to 12 cm with an average of 7 cm. They were located in the distal femur in 11 cases and middle third of the femur in three cases. All cases were treated by the synthetic membrane technique in one stage surgery. Surgicel was used as a synthetic membrane and both the fibular strut autograft and morselized allograft were used to fill the defects in all patients.

RESULTS

All cases healed without additional procedures after the index surgery except in three cases. The time-to-bone union ranged from six to 13 months with an average of eight months. After physiotherapy all patients regained good range of knee movements except two cases. The complications included deep wound infection in two cases, nonunion of the graft in one case and joint stiffness in two cases.

CONCLUSION

Primary bone graft in surgicel as a synthetic membrane is a good technique for management of post-traumatic bone defects. It reduces the time and number of surgeries required for reconstruction of this difficult problem.

Reconstruction of infected nonunion of the distal humerus by Ilizarov external fixator

BACKGROUND

Infected nonunion of the distal humerus represents a true challenge as the fragment is usually small and difficult for fixation. The aim of the present study is to assess the results of Ilizarov external fixator in management of infected nonunion of the distal third humerus.

MATERIAL AND METHODS

Twenty-three patients with infected nonunion of the distal humerus were included in this study. The ages ranged from 19 to 58 years with an average of 35 years. Seventeen cases were males and 6 were females. All patients were treated by radical debridement and application of Ilizarov external fixator in one stage surgery.

RESULTS

Bony union was achieved in all cases. Bone graft was required in 12 patients with hypotrophic nonunion. The external fixation time ranged from 4 to 9 months with an average of 5.6 months. Infection was controlled in all cases without recurrence during the period of follow up. The complications included pin tract infection in 7 cases, radial nerve injury in one case, elbow stiffness in 4 cases and refracture after frame removal in one case.

CONCLUSION

Ilizarov external fixator is effective in management of infected nonunion of the distal humerus. The thin tensioned wires produce good grip in the small or osteoporotic bone fragments.

The Fate of Patients After a Staged Nonunion Procedure for Known Infection

OBJECTIVES

To determine the factors associated with successful union and eradication of infection in the setting of staged procedures to treat obviously infected nonunions of long bones. We hypothesize that patients with positive intraoperative cultures obtained at the time of definitive surgery for infected nonunions are more likely to have persistent nonunion than those with negative cultures.

DESIGN

Multicenter retrospective review.

SETTING

Eight academic Level 1 trauma centers.

PATIENTS/PARTICIPANTS

Patients who underwent staged management for obviously infected nonunion of a long bone.

MAIN OUTCOME MEASUREMENTS

For each patient, initial fracture management, management of retained implants, number of debridements, grafting, bacteriology, antibiotic course, bone defect management, soft-tissue coverage, and definitive surgery performed were reviewed.

RESULTS

A total of 134 patients were treated with staged procedures for obviously infected nonunion of a long bone (mean age 49 years, 60% open fractures, and mean follow-up 22 months). During definitive procedures, 120 patients had intraoperative cultures taken with 43% having positive cultures. For culture-positive patients, 41 patients achieved eventual union and 10 had persistent nonunion. Of 69 culture-negative patients, 66 achieved eventual union and 3 had persistent nonunion. The number of patients with union versus persistent nonunion was statistically significant between culture-positive and culture-negative groups (P = 0.015).

CONCLUSIONS

Management of infected nonunion in long bones with staged treatments before definitive fixation are beneficial but ultimately less effective when performed in the setting of positive bacterial cultures at the time of definitive management.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Tibial Nail Combined with Vacuum Sealing Drainage for Gustilo Grade IIIB Open Tibial Fractures: A Patient Series

Gustilo grade IIIB open tibial fractures are relatively difficult to treat. We investigated the treatment effects of tibial intramedullary nails combined with vacuum sealing drainage (VSD) for Gustilo grade IIIB open tibial fractures. From March 2015 to March 2017, 13 cases of Gustilo grade IIIB open tibial fractures were treated with Expert Tibial Nails combined with VSD. Causes of injury included falls from a height (n = 9, 69.2%) and road accidents (n = 4, 30.8%). The duration from time of injury to hospital intake was 7.3 hours (range 5 to 9.5), and the time between injury and operation was 6.7 days (range 3 to 11). Six months after the operation, overall patient general health was investigated via the American Orthopaedic Foot and Ankle Society (AOFAS) ankle score and the physical and mental health dimensions of the Short-Form Health Survey 36 (SF-36). Postoperative complications and infections also were recorded. The results indicated that the median AOFAS score was 93.7 (range 89 to 97), with all individuals having either excellent (90 to 100; n = 10, 76.9%) or good (80 to 89; n = 3, 23.1%) outcomes. The median physical SF-36 score was 83.1 (range 72.5 to 93.0), and the median mental SF-36 score was 80.6 (range 69.7 to 92.0). Moreover, there were no instances of tibial shortening, neurovascular injury, postoperative complications, implant failure, malunion, or serious infections. In conclusion, intramedullary tibial nail combined with VSD is a safe and effective method to treat type grade IIIB open tibial fractures.

Management of critical-sized bone defects in the treatment of fracture-related infection: a systematic review and pooled analysis

PURPOSE

This systematic review determined the reported treatment strategies, their individual success rates, and other outcome parameters in the management of critical-sized bone defects in fracture-related infection (FRI) patients between 1990 and 2018.

METHODS

A systematic literature search on treatment and outcome of critical-sized bone defects in FRI was performed. Treatment strategies identified were, autologous cancellous grafts, autologous cancellous grafts combined with local antibiotics, the induced membrane technique, vascularized grafts, Ilizarov bone transport, and bone transport combined with local antibiotics. Outcomes were bone healing and infection eradication after primary surgical protocol and recurrence of FRI and amputations at the end of study period.

RESULTS

Fifty studies were included, describing 1530 patients, the tibia was affected in 82%. Mean age was 40 years (range 6-80), with predominantly male subjects (79%). Mean duration of infection was 17 months (range 1-624) and mean follow-up 51 months (range 6-126). After initial protocolized treatment, FRI was cured in 83% (95% CI 79-87) of all cases, increasing to 94% (95% CI 92-96) at the end of each individual study. Recurrence of infection was seen in 8% (95% CI 6-11) and amputation in 3% (95% CI 2-3). Final outcomes overlapped across treatment strategies.

CONCLUSION

Results should be interpreted with caution due to the retrospective and observational design of most studies, the lack of clear classification systems, incomplete data reports, potential underreporting of adverse outcomes, and heterogeneity in patient series. A consensus on classification, treatment protocols, and outcome is needed to improve reliability of future studies.

What is the optimal timing for bone grafting during staged management of infected non-unions of the tibia? A systematic review and best evidence synthesis

PURPOSE

To summarize the best available evidence with regards to timing of staged bone grafting for infected tibial non-union, and to extract evidence-based criteria indicating when bone grafting can be safely performed.

METHODS

Medline, Embase, Scopus, and Google Scholar were searched, and publications of evidence Level I-IV from 2000 to 2020 were included. Risk of bias was assessed with the Cochrane Collaboration's Risk of Bias Tool and ROBINS-I tool. Study quality was assessed with the GRADE system, Coleman methodology score, and Methodological Index for Non-Randomized Studies (MINORS). Heterogeneity was assessed with the I² statistic. A forest plot was used to pool the timing of bone grafting for all included studies. For data synthesis and analysis, a best evidence synthesis was used.

RESULTS

A total of 15 studies were included (353 cases). Risk of bias was high in 8 studies and the quality for 14 studies was assessed as very low, with a mean Coleman score of 33.5 and a mean MINORS score of 7.9. The mean time from the index surgery to bone grafting was 7.03 weeks ranging from 2 to 15 weeks (lower limit 6 weeks, upper limit 8.07 weeks). Best evidence analysis demonstrated that 8 of the 15 studies (53%) with 237 cases (67%) performed staged bone grafting inside this window. Union was achieved in 92%.

CONCLUSION

The results of this best evidence systematic review suggest that, for most infected tibial non-unions, secondary bone grafting can be successfully performed between 6-8 weeks with expected union rates over 90%.

Two-stage treatment with sliding fibular flap technique for chronic infected nonunion of the tibia

PURPOSE

To assess the effectiveness of two-stage treatment with the fibular sliding technique in chronic infected nonunion of the tibia.

METHODS

The study included patients who were diagnosed with long-term chronic infected tibial nonunion following trauma and treated with the two-stage technique between January 2010 and November 2017. Patients with (1) intra-articular fractures of the distal third of the tibia and fibula, (2) pathological fracture resulting in bone loss or (3) neurological and vascular pathologies of the limbs were excluded. The operation consisted of two stages and the main goal in the first stage was to control the infection and in the second stage to control the healing of the bone. Functional & radiographic results and complications were evaluated according to Paley's criteria.

RESULTS

The patients comprised 14 males and 5 females with a mean age of 37.4 years (range, 21-52 years). Patients were followed up for an average of 27 months (range, 15-38 months). The microorganisms produced from these patients were Staphylococcus aureus in 13 patients, Pseudomonas aeruginosa in 4 patients and no bacteria in 2 patients. After the first stage operation, superficial skin necrosis developed in 1 patient. In another patient, there was a persistent infection, although union was achieved. For the entire patient group, union was observed at the end of 7.44 months (range, 7-11 months). Based on Paley's criteria, there were 16 (84.2%) patients with excellent scores, 2 (10.5%) good scores and 1 (5.3%) fair scores radiologically; while regarding the tibial function, 15 (78.9%) patients had excellent scores, 3 (15.8%) good scores, and 1 (5.3%) fair scores. No patients had poor radiological or functional score.

CONCLUSION

Two-stage treatment can be considered as an alternative for fractures in regions that are susceptible to many and persistent complications, such as the tibia. This technique has the advantages of short operation time, minimal blood loss, no excessive tissue damage and not very technique-demanding (a short learning curve with no requirement for an experienced team).

Cost-effectiveness Applications of Patient-reported Outcome Measures (PROMs) in Spine Surgery

Because of the rising health care costs in the United States, there has been a focus on value-based care and improving the cost-effectiveness of surgical procedures. Patient-reported outcome measures (PROMs) can not only give physicians and health care providers immediate feedback on the well-being of the patients but also be used to assess health and determine outcomes for surgical research purposes. Recently, PROMs have become a prominent tool to assess the cost-effectiveness of spine surgery by calculating the improvement in quality-adjusted life years (QALY). The cost of a procedure per QALY gained is an essential metric to determine cost-effectiveness in universal health care systems. Common patient-reported outcome questionnaires to calculate QALY include the EuroQol-5 dimensions, the SF-36, and the SF-12. On the basis of the health-related quality of life outcomes, the cost-effectiveness of various spine surgeries can be determined, such as cervical fusions, lumbar fusions, microdiscectomies. As the United States attempts to reduce costs and emphasize value-based care, PROMs may serve a critical role in spine surgery moving forward. In addition, PROM-driven QALYs may be used to analyze novel spine surgical techniques for value-based improvements.

Evidence-Based Recommendations for Local Antimicrobial Strategies and Dead Space Management in Fracture-Related Infection

Fracture-related infection (FRI) remains a challenging complication that imposes a heavy burden on orthopaedic trauma patients. The surgical management eradicates the local infectious focus and if necessary facilitates bone healing. Treatment success is associated with debridement of all dead and poorly vascularized tissue. However, debridement is often associated with the formation of a dead space, which provides an ideal environment for bacteria and is a potential site for recurrent infection. Dead space management is therefore of critical importance. For this reason, the use of locally delivered antimicrobials has gained attention not only for local antimicrobial activity but also for dead space management. Local antimicrobial therapy has been widely studied in periprosthetic joint infection, without addressing the specific problems of FRI. Furthermore, the literature presents a wide array of methods and guidelines with respect to the use of local antimicrobials. The present review describes the scientific evidence related to dead space management with a focus on the currently available local antimicrobial strategies in the management of FRI. LEVEL OF EVIDENCE:: Therapeutic Level V. See Instructions for Authors for a complete description of levels of evidence.

Current Insights in the Application of Bone Grafts for Local Antibiotic Delivery in Bone Reconstruction Surgery

Introduction: Bone implant related infection is still one of the biggest challenges in bone and joint surgery. Antibiotic impregnated bone grafts seem to be promising in both treatment and prevention of these infections. However, great variance in methodology predominates this field of research. This paper gives an overview of the published literature.

Methods: The PRISMA-flowchart was used as protocol for article selection. Medline was searched and articles were selected in accordance with predetermined exclusion criteria.

Results: Forty-eight articles were included in the synthesis. Topics including bone graft type, manipulations of the graft, elution profile, bacterial inhibition, osteotoxicity, incorporation, special impregnation methods, clinical use and storage were investigated.

Therapeutically, high initial levels seem appropriate for biofilm eradication. A single stage procedure in the treatment of bone implant related infection seems feasible. Prophylactically, the literature indicates a reduction of postoperative infections when using antibiotic impregnated bone grafts.

Conclusion: Bone grafts are a suitable carrier for local antibiotic application both therapeutically and prophylactically.

Insights into treatment and outcome of fracture-related infection: a systematic literature review

INTRODUCTION

Standardized guidelines for treatment of fracture-related infection (FRI) are lacking. Worldwide many treatment protocols are used with variable success rates. Awareness on the need of standardized, evidence-based guidelines has increased in recent years. This systematic literature review gives an overview of available diagnostic criteria, classifications, treatment protocols, and related outcome measurements for surgically treated FRI patients.

METHODS

A comprehensive search was performed in all scientific literature since 1990. Studies in English that described surgical patient series for treatment of FRI were included. Data were collected on diagnostic criteria for FRI, classifications used, surgical treatments, follow-up protocols, and overall outcome. A systematic review was performed according to the PRISMA statement. Proportions and weighted means were calculated.

RESULTS

The search yielded 2051 studies. Ninety-three studies were suitable for inclusion, describing 3701 patients (3711 fractures) with complex FRI. The population consisted predominantly of male patients (77%), with the tibia being the most commonly affected bone (64%), and a mean of three previous operations per patient. Forty-three (46%) studies described FRI at one specific location. Only one study (1%) used a standardized definition for infection. A total of nine different classifications were used to guide treatment protocols, of which Cierny and Mader was used most often (36%). Eighteen (19%) studies used a one-stage, 50 (54%) a two-stage, and seven (8%) a three-stage surgical treatment protocol. Ten studies (11%) used mixed protocols. Antibiotic protocols varied widely between studies. A multidisciplinary approach was mentioned in only 12 (13%) studies.

CONCLUSIONS

This extensive literature review shows a lack of standardized guidelines with respect to diagnosis and treatment of FRI, which mimics the situation for prosthetic joint infection identified many years ago. Internationally accepted guidelines are urgently required to improve the quality of care for patients suffering from this significant complication.

One-stage surgery for adult chronic osteomyelitis: concomitant use of antibiotic-loaded calcium sulphate and bone marrow aspirate

PURPOSE

To report our experience with one-stage treatment of chronic osteomyelitis using a prospective protocol involving the concomitant use of the antibiotic-loaded calcium sulphate pellets with addition of bone marrow aspirate after bony debridement.

PATIENTS AND METHODS

A total of 30 patients with the mean age of 26.2 years were treated according to a protocol that included (1) surgical debridement of bone and infected tissues, (2) local antibiotic therapy including vancomycin and garamycin loaded on calcium sulphate space filling biodegradable pellets, (3) bone marrow aspirate added to the biocomposite, (4) primary closure with external fixation (when needed) and (5) intravenous antibiotics according to culture and sensitivity results.

RESULTS

After a minimum of one year follow-up, infection was eradicated in 23 (76.7%) patients, the average rate of filling of the bony defect was 70.47%, complete filling of defect in 15 patients (50%) and pathological fracture in one patient.

CONCLUSION

The technique proved safety and efficacy in eradicating the infection and bony healing of the defects after debridement. Simple bone marrow aspiration is cheap, reproducible, safe and not exhausting the scanty autograft resources.

Applications of Local Antibiotics in Orthopedic Trauma

Local antibiotics have a role in orthopedic trauma for both infection prophylaxis and treatment. They provide the advantage of high local antibiotic concentration without excessive systemic levels. Nonabsorbable polymethylmethacrylate (PMMA) is a popular antibiotic carrier, but absorbable options including bone graft, bone graft substitutes, and polymers have gained acceptance. Simple aqueous antibiotic solutions continue to be investigated and appear to be clinically effective. For established infections, such as osteomyelitis, a combination of surgical debridement with local and systemic antibiotics seems to represent the most effective treatment at this time. Further investigation of more effective local antibiotic utilization is ongoing.

Polymer-controlled release of tobramycin from bone graft void filler

Despite clinical, material, and pharmaceutical advances, infection remains a major obstacle in total joint revision surgery. Successful solutions must extend beyond bulk biomaterial and device modifications, integrating locally delivered pharmaceuticals and physiological cues at the implant site, or within large bone defects with prominent avascular spaces. One approach involves coating clinically familiar allograft bone with an antibiotic-releasing rate-controlling polymer membrane for use as a matrix for local drug release in bone. The kinetics of drug release from this system can be tailored via alterations in the substrate or the polymeric coating. Drug-loaded polycaprolactone coating releases bioactive tobramycin from both cadaveric-sourced cancellous allograft fragments and synthetic hybrid coralline ceramic bone graft fragments with similar kinetics over a clinically relevant 6-week timeframe. However, micron-sized allograft particulate provides extended bioactive tobramycin release. Addition of porogen polyethylene glycol to the polymer coating formulation changes tobramycin release kinetics without significant impact on released antibiotic bioactivity. Incorporation of oil-microencapsulated tobramycin into the polymer coating did not significantly modify tobramycin release kinetics. In addition to releasing inhibitory concentrations of tobramycin, antibiotic-loaded allograft bone provides recognized beneficial osteoconductive potential, attractive for decreasing orthopedic surgical infections with improved filling of dead space and new bone formation.

In vitro efficiency of vancomycin containing experimental drug delivery systems

Biofilm-forming Staphylococcus epidermidis strains are common cause of the periprosthetic infection. The treatment of the periprosthetic infection is very problematic, so the prevention of these infections by an antibiotic containing prothesis could be an option for prevention.The purpose of the present study was to examine the in vitro effects of drug delivery systems (DDSs), namely Wax 1 and Wax 2 with different vancomycin content: 0.5, 1, 2 and 4 mg. In order to control the antibacterial activity of DDSs killing curve study was performed and in order to determine the antibiotic release and the antibiotic peak concentration from the DDSs biological assay was carried out.The time kill curve studies showed, that both DDSs with all vancomycin concentration decreased significantly the bacterial counts, however, Wax 2 with 4 mg vancomycin significantly decreased the bacterial count than all the other groups.The vancomycin release was the best with the highest peak concentration from DDSs with 4 mg vancomycin contain; it was significantly better than in the other groups, however, no significant difference was observed between Wax 1 and Wax 2 in this respect.These findings suggest that Wax 2 with 4 mg vancomycin content could be a potential agent for clinical use.

Prophylactic intrawound application of vancomycin powder in instrumented spinal fusion surgery

Objective

We evaluated the effect of intrawound application of vancomycin powder for infection prophylaxis in wounds caused by instrumented spinal surgery.

Methods

From July 2012 to December 2012, 74 instrumented spinal fusion procedures were performed by 1 neurosurgeon at a single institute. We divided the patients into 2 groups, depending on the use of local application of vancomycin powder: Group A (intrawound application of vancomycin powder with perioperative intravenous cefazolin) and Group B (perioperative intravenous cefazolin alone). A retrospective cohort comparative study was conducted between the 2 groups. The age, sex, comorbidities, smoking, surgical procedure, and surgical site infection (SSI) of consecutive patients were analyzed.

Results

Among the 74 patients, 34 patients were assigned to group A and 40 patients to group B. No wound infections were found in group A. However, in group B, 5 cases of SSI (12.5%) were found. A statistically significant reduction in SSI incidence was observed in group A (p<0.033). The 5 cases of SSI in group B consisted of 3 cases of deep wound infection and 2 cases of superficial wound infection. All SSIs were found in cases of posterior approach surgery and tended to be more frequent in older patients.

Conclusion

Adjunctive intrawound local application of vancomycin powder is a simple uncomplicated procedure and can result in a significant reduction of SSI in instrumented spinal fusions. Furthermore, culture of the drainage tip is very important for confirmation of deep wound infection.

Pharmacokinetic properties and systemic safety of vancomycin-impregnated cancellous bone grafts in the treatment of spondylodiscitis

The aim of the present study was to investigate the local pharmacokinetic properties and the systemic safety of vancomycin-impregnated cancellous bone grafts in the treatment of spondylodiscitis. Between 2010 and 2012, 8 patients (5 females, 3 males, mean age 68.75 y.) were treated with this method. Local vancomycin concentrations reached median values of 179 µg/mL (maximum 365 µg/mL) on day 1, decreasing to 98 µg/mL on day 3. The urine vancomycin concentrations showed similar pharmacokinetic properties as those locally determined. On day 1, median values were at 28.05 µg/mL (maximum 287 µg/mL). All serum vancomycin concentrations were in all cases and on every day below <2 µg/mL. The median serum creatinine values were preoperatively 0.87 mg/dL, followed by 0.625 mg/dL, 0.705 mg/dL, and 0.835 mg/dL on day 7, 14, and 28, respectively. No cases of ototoxicity could be observed. At a mean follow-up of 16.5 [4–36] months no cases of reinfections or persistent infections could be seen. In conclusion, the implantation of vancomycin-loaded cancellous bone grafts is an effective option in the treatment of spondylodiscitis with a high infection eradication rate and no risk of any systemic toxicity. The pharmacokinetic properties can be easily monitored locally, in the urine and the serum.

Exchange reamed nailing compared to augmentation compression plating leaving the inserted nail in situ in the treatment of aseptic tibial non-union: a two-centre study

BACKGROUND

A remarkable number of investigations are available treating tibial non-unions by exchange reamed nailing (ERN). Only few authors reported positive results after augmentation compression plating (ACP) for the same entity. To our knowledge no systematic study is published comparing ERN vs. ACP, so that this trial compares ACP leaving the already inserted un-reamed nail in situ against ERN in the treatment of aseptic tibial non-union, analysing success rate, time for union and operation time.

PATIENTS AND METHODS

Forty-eight patients with aseptic hypertrophic diaphyseal tibial non-union treated previously by un-reamed nailing were included retrospectively in this two-centre study. Group A consisted of 25 patients with ERN and group B of 23 patients with ACP leaving the underlying un-reamed nail in situ.

RESULTS

Mean follow-up was 3.8 years. Union was achieved in 24 out of 25 cases (96 %) for group A and in 22 out of 23 cases (95.6 %) for group B. Time needed for union varied; an average of 29 weeks for group A and 14 weeks for group B. The mean operation time for group A was 99 min, while it was 65 min for group B.

CONCLUSIONS

ERN and ACP with remaining pre-existing nail in situ are both safe and straightforward surgical procedures with equivalent high success rates of about 95 %. ACP has the advantage of less time for union and operating time in this series, but is associated with the disadvantage of requiring an additional incision and complaints associated to the plate requiring implant removal.

Reconstruction using femoral head allograft in revision total knee replacement

Structural allografts may be used to manage uncontained bone defects in revision total knee replacement (TKR). However, the availability of cadaver grafts is limited in some areas of Asia. The aim of this study was to evaluate the mid-term outcome of the use of femoral head allografts for the reconstruction of uncontained defects in revision TKR, focusing on complications related to the graft.

We retrospectively reviewed 28 patients (30 TKRs) with Anderson Orthopaedic Research Institute (AORI) type 3 bone defects, who underwent revision using femoral head allografts and stemmed components. The mean number of femoral heads used was 1.7 (1 to 3). The allograft–host junctions were packed with cancellous autograft.

At a mean follow-up of 76 months (38 to 136) the mean American Knee Society knee score improved from 37.2 (17 to 60) pre-operatively to 90 (83 to 100) (p < 0.001). The mean function score improved from 26.5 (0 to 50) pre-operatively to 81 (60 to 100) (p < 0.001). All the grafts healed to the host bone. The mean time to healing of the graft was 6.6 months (4 to 16). There have been no complications of collapse of the graft, nonunion, infection or implant loosening. No revision surgery was required.

The use of femoral head allografts in conjunction with a stemmed component and autogenous bone graft in revision TKR in patients with uncontained bone defects resulted in a high rate of healing of the graft with minimal complications and a satisfactory outcome. Longer follow-up is needed to observe the evolution of the graft.

Cite this article: Bone Joint J 2013;95-B:643–8.

High success rate for augmentation compression plating leaving the nail in situ for aseptic diaphyseal tibial nonunions

OBJECTIVES

To evaluate adjunctive compression plating leaving the previously unreamed inserted intramedullary nail (URIMN) in situ for treating a resultant diaphyseal tibial nonunion.

DESIGN

Retrospective study.

SETTING

Level 1 trauma center (University Hospital).

PATIENTS/PARTICIPANTS

Patients treated by URIMN for diaphyseal tibial fractures that developed an aseptic hypertrophic nonunion.

INTERVENTION

Dynamization of the nail and compression plating leaving the URIMN in situ.

MAIN OUTCOME MEASUREMENTS

Radiographic and clinical parameters.

RESULTS

The mean follow-up was 3.8 years (range 2-7 years). Mean time for healing was 15 weeks with a mean operation time of 63 minutes. Union occurred in 27/28 (96.4%). There were no infections.

CONCLUSIONS

This simple technique seems to have a high success rate and should be considered when a nonunion occurs after URIMN. The need for an additional incision and removal of symptomatic implants remains a disadvantage.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Antibiotic-impregnated bone grafts in orthopaedic and trauma surgery: a systematic review of the literature

There exist several options for local antibiotic therapy in orthopaedic and trauma surgery. Over the past years, the use of antibiotic-impregnated bone grafts (AIBGs) has become a popular procedure in the treatment of bone and joint infections. A major advantage of AIBGs involves the possibility of impregnation of various antibiotics depending on the sensitivity profile of the causative organism, whereas an additional surgery with removal of the antibiotic carrier is not necessary, as in the use of antibiotic-loaded bone cement. However, generalized conclusions cannot be clearly drawn from the existing literature due to differences of bone used, impregnation method, antibiotics, their doses, laboratory circumstances, or clinical indications. The present work reviews the literature regarding this topic and sheds some light onto the choice of bone and antibiotics, manufacturing details, and clinical experience.

Intrawound application of vancomycin for prophylaxis in instrumented thoracolumbar fusions: efficacy, drug levels, and patient outcomes

STUDY DESIGN

A retrospective cohort study from a single institution of a consecutive series of spine surgery patients.

OBJECTIVE

To evaluate the safety and efficacy of adjunctive local application of vancomycin for infection prophylaxis in posterior instrumented thoracic and lumbar spine wounds compared to IV cephalexin alone.

SUMMARY OF BACKGROUND DATA

Cephalosporin resistant strains of staphylococcus (MRSA and coagulase negative staph) have diminished the efficacy of intravenous antibiotic prophylaxis for instrumented spine fusion. Intravenous vancomycin prophylaxis has not been shown to decrease wound infection rates compared to IV cephalosporins. Adjunctive application of vancomycin powder in wounds for instrumented spinal fusion surgery may decrease infection rates.

METHODS

Since 2000, 1732 consecutive thoracic and lumbar posterior instrumented spinal fusions have been performed with routine 24 hours of perioperative intravenous antibiotic prophylaxis with cephalexin. Since 2006, 911 of these instrumented thoracic and lumbar cases had 2 g of vancomycin powder applied to the wound before closure in addition to intravenous antibiotics. A retrospective review for infection rates and complications was performed. Oswestry and SF-36 outcomes instruments were completed before surgery, immediately after surgery, and at latest follow-up. The average follow-up is 2.5 years, range 1 to 7 years.

RESULTS

Eight hundred twenty-one posterior instrumented thoracic and lumbar fusions were preformed using intravenous cephalexin prophylaxis with a total of 21 deep wound infections (2.6%). Coag negative staph was the most commonly isolated organism. Nine hundred eleven posterior instrumented thoracic and lumbar fusions have been performed with IV cephalexin plus adjunctive local vancomycin powder with two deep wound infections (0.2%). The reduction in wound infections was statistically significant (P < 0.0001). There were no adverse clinical outcomes or wound complications related to the local application of vancomycin.

CONCLUSION

Adjunctive local application of vancomycin powder decreases the postsurgical wound infection rate with statistical significance in posterior instrumented thoracolumbar spine fusions.

In vitro elution of moxifloxacin from cancellous bone allografts

The characteristics of cancellous bone allografts as carriers of moxifloxacin are described. Particles of cancellous bone were compressed into a wire-mesh cylinder and impregnated into a solution of moxifloxacin for different time periods. Five replicas were impregnated for 1 h; another five for 24 h; and another five for 48 h. Impregnated allografts were then transferred into vials containing 5 ml of Mueller-Hinton broth and incubated at 37 degrees C. Broth was replaced daily. Concentrations of moxifloxacin in broth were determined after analysis by an high performance liquid chromatography system. Moxifloxacin was eluted at very high concentrations within the first days. Concentrations remained above 100 microg/ml until day 8 and above 40 microg/ml until day 20. It is concluded that cancellous bone allografts may allow the adequate in vitro elution of moxifloxacin. The latter results support their application in experimental models of osteomyelitis.

Decal bone matrix as a local antibiotic delivery vehicle in a MRSA-infected bone model: An experimental study

BACKGROUND

Polymethyl methacrylate (PMMA) antibiotic beads though have proved their utility as a local antibiotic delivery system, however, there are limitations. Decalcified bone matrix (DBM) as a vehicle of antibiotics can serve the purpose, provided a minimum inhibitory concentration is sustained. Healing of the defect and avoiding the second surgery is another advantage. We studied the DBM as the delivery vehicle for vancomycin in controlling the methicillin-resistant Staphylococcus aureus (MRSA) osteomyelitis as well as healing of the cavity simultaneously in an experimental study.

MATERIALS AND METHODS

An in vitro study was conducted to optimize vancomycin impregnation in the DBM. For the in vivo study, a unicortical defect was created in the metaphysis of the distal femur in 18 rabbits. After contaminating the defect with MRSA, rabbits were divided into three groups. Group I (eight limbs) received no graft. Defects in group II (11 limbs) were filled with plain DBM chips and in group III (14 limbs), cavities were implanted with vancomycin-impregnated decal bone chips. Rabbits were assessed by clinical, radiological, histological, gross examination and bacterial load assay. High Performance Liquid Chromatography HPLC analysis of vancomycin in group III was done to assess the concentration in DBM chips.

RESULTS

In group I, the infection persisted throughout the period of the study. Group II showed the fulminated infection at the grafted site with DBM chips sequestrating out. Vancomycin-impregnated decal chips in group III did not show any sign of infection and eventually incorporated. The bacterial load study showed a progressive load change and HPLC revealed an effective antibiotic concentration up to 3 weeks in both in vitro and in vivo.

CONCLUSION

Decal bone chips were effective as the local antibiotic delivery vehicle in preventing the MRSA osteomyelitis model. It eluted vancomycin significantly and the graft uptake was also excellent. Allogeneic decal grafts eliminated the need for second surgery and acted as an excellent delivery vehicle for antibiotics.

Infected nonunions of long bones of the upper extremity: staged reconstruction using polymethylmethacrylate and bone graft impregnated with antibiotics

This case series evaluates 12 patients presenting posttraumatic infected nonunions affecting long bones of the upper extremity, treated with staged reconstruction using polymethylmethacrylate spacers with antibiotics in the first stage and bone graft impregnated with antibiotics in the definitive surgical procedure. Five nonunions affected the humerus, four the ulna and three the radius. All nonunions were atrophic. Patient's age averaged 35.9 years. The size of the bony defect averaged 2.8 cm. Time between original trauma and revision surgery averaged 9.6 months. Follow-up averaged 19 months. All nonunions healed after an average of 5 months. DASH score at last follow-up averaged 15 points. Although two surgical procedures are needed, one to cure infection and another to achieve bony union, this approach for posttraumatic infected nonunions of long bones of the upper extremities represents a valid treatment alternative.

Comparison of various surgical methods in the treatment of implant-related infection

The treatment of implant-related infections is troublesome. This study was conducted to compare the effectiveness of three different surgical modalities in the treatment of implant-related infection. A total of 32 Wistar albino rats were randomised into four groups after the establishment of implant-related infection: no treatment, surgical débridement, antibiotic-loaded bone cement and antibiotic-loaded autogenous bone. Microbiological colony counts were made at the sixth week in order to evaluate the effectiveness of of the treatments. The antibiotic-loaded bone cement group revealed superior results compared with the other groups in terms of reduction of microbiological colonies. Three animals in the bone cement group revealed extensive infection. Although antibiotic-loaded bone cement showed superiority over other treatment modalities, it should be employed after an unsuccessful trial of débridement because of the risk of extensive infection.

In vitro release of fusidic acid and teicoplanin from cancellous bone allografts

The characteristics of cancellous bone allografts as carriers of fusidic acid and teicoplanin are described. Particles of cancellous bone were compressed into a wiremesh cylinder; five replicas were impregnated for one hour into fusidic acid; and another five for one hour into teicoplanin. Elution was estimated daily. Concentrations of fusidic acid and teicoplanin were determined by a microbiological assay. Both antibiotics were eluted at very high concentrations within the first days. Allografts impregnated in fusidic acid provided concentrations above 20 microg/ml for 20 days. Eluted teicoplanin after day 4 was below 10 microg/ml. It is concluded that cancellous bone allografts may allow adequate in vitro elution of fusidic acid but not of teicoplanin. The latter results support their application in experimental models of osteomyelitis.

Fibula and tibia fusion with cancellous allograft vitalised with autologous bone marrow: first results for infected tibial non-union

BACKGROUND AND AIMS

Autogenous bone grafting has been used in reconstructing bone defects and in stimulating fracture healing, producing high healing rates in the treatment of infected tibial non-unions. A novel therapeutic alternative is now available known as "vitalised allograft", a cancellous bone graft procured from femoral heads from living human donors and "vitalised" through the injection of autologous bone marrow. The aim of this study is to summarise the initial results of the fibula and tibia fusion using vitalised cancellous allograft in the treatment of infected tibial non-unions.

PATIENTS AND METHODS

We initiated a follow-up of 15 prospective non-randomized patients who received a vitalised allograft in the treatment of infected tibial non-unions in order to produce bony union. The patients included 13 men and 2 women with an average age of 48 years. All patients received a multi-stage surgical approach. After establishing an infection-free environment, allogenic cancellous bone grafting was performed, intended as the final surgical procedure in fibula and tibia fusion. Our follow-up included a clinical and radiographic investigation of the calf in four planes. We analysed union-rate and time required for bony consolidation, as well as recurrent infections, re-fractures, potential graft-resorption, and time needed for graft and bone remodelling.

RESULTS

With an average follow-up of 17.1 months, infection control was obtained in 14 of 15 patients, producing an infection arrest rate of 93.3%. Radiographs indicated consolidation in 11 out of 15 cases, with a union rate of 73.3%. Bone union was achieved on average in 17.1 weeks.

CONCLUSIONS

Fibula and tibia fusion with allogenic cancellous bone grafting, vitalised through autogenic bone marrow, could well become an innovative treatment option for infected tibial non-unions. We need, however, to analyse a higher number of cases over a longer follow-up period in order to assess more accurately recurrent infections and re-fractures.

Revisional hindfoot arthrodesis

Salvage of a failed hindfoot arthrodesis is an extensive undertaking for the surgeon and patient. With increased morbidity and postoperative convalescence and complications, patients must understand the risk involved in this type of revisional surgery. This article provides a systematic approach to revisional hindfoot arthrodeses, focusing on patient evaluation, surgical technique, and postoperative treatment.

Management of infected nonunion of long bones: the last decade (1996-2006)

Infected nonunion is one of the most challenging orthopaedic complications to manage. There is considerable morbidity associated with infected nonunion. There is significant impact on the life of the patient; social, financial, physical, and mental. Infected nonunion may be a limb-threatening complication. Significant progress has been made in the management of infected nonunion in the last decade. There are clear guidelines for pre-operative evaluation and treatment strategy. The recommended strategy is the 'infection-elimination first' strategy. This strategy involves two steps: control of infection by local radical debridement of dead tissue followed by reconstruction. There are four operative techniques (with considerable overlap among them) which have been used in the past decade: Ilizarov, intramedullary devices with or without the use of external fixator, free tissue transfer, and in situ reconstruction. Bone results are, in general, better compared to functional results. Overall, the outcome following treatment of infected nonunion are good to excellent.

Infected nonunion of the long bones

BACKGROUND

Although definitions vary, infected nonunion has been defined as a state of failure of union and persistence of infection at the fracture site for 6 to 8 months.>). Infected nonunions of the supracondylar region of the femur are uncommon and are mostly due to a severe open fracture with extensive comminution and segmental bone loss or after internal fixation of a comminuted closed fracture. Associated factors include exposed bone devoid of vascularized periosteal coverage for more than 6 weeks, purulent discharge, a positive bacteriological culture from the depth of the wound, and histologic evidence of necrotic bone containing empty lacunae. Soft-tissue loss with multiple sinuses, osteomyelitis, osteopenia, complex deformities with limb-length inequality, stiffness of the adjacent joint, polybacterial multidrug-resistant infection, and smoking all complicate treatment and recovery. Although uncommon in incidence, infected nonunions of the long bones present a great challenge to the orthopaedic surgeon in providing optimal treatment of this entity. To give direction to the optimal strategy, this systematic review was performed.

OBJECTIVE

We aimed to review the highest level of available evidence on the operative management of infected nonunions of the long bones.

Alendronate enhances antibiotic-impregnated bone grafts in the treatment of osteomyelitis

Bisphosphonates are systemic drugs. There is limited knowledge about their effects when applied locally and in osteomyelitis treatment. A prospective longitudinal randomised controlled study was designed in rat tibia to test the efficacy of local or systemically administered bisphosphonates for controlling the osteolytic reactions and possible effects on local infection control. Tibial osteomyelitis was induced in 72 Wistar albino rats with Staphylococcus aureus ATCC 25923 strain. Débridement was performed on all rats in all groups. No other treatment was given to the control group. Treatment groups received "plain bone grafts", "vancomycin-loaded bone grafts", "vancomycin-loaded bone grafts+systemic alendronate", "alendronate-impregnated bone grafts" and "vancomycin+alendronate-impregnated grafts". Study results were evaluated by swab cultures, radiology, quantitative computed tomography, dual-energy X-ray absorptiometry (DEXA) and histopathology. S. aureus was eradicated in groups II and IV by the sixth week. Diaphyseal widening, bone deformation, diaphyseal widening and osteolysis scores were significantly lower (p < 0.05), and bone mineral content, density measurements and DEXA scores were significantly higher (p = 0.001) with alendronate administration. Histology revealed marked osteoblastic activity. Local alendronate interfered with local infection control. Even though local alendronate at the given dose has stronger effects, the possible effects on the local inflammatory process needs to be clarified.