Infected Osteosynthesis Research Articles

Calvarial bone grafts to augment the alveolar process in partially dentate patients: a prospective case series

BackgroundCalvarial bone grafts as a pre-implant augmentation procedure are mostly used to reconstruct the edentulous maxilla, although calvarial grafts could also be used in the partially dentate patients needing extensive bone grafting.MethodsIn 7 consecutive partially dentate patients needing bone grafting because of a large bony defect as a result of trauma (n = 1), oligodontia (n = 1), failed previous bone augmentation (n = 1), or atrophy (n = 4), the alveolar process was reconstructed with calvarial bone as a pre-implant procedure.ResultsA total of 30 implants was placed either immediate at the time of bone grafting (13 implants) or after a healing time of 4 months when immediate placement was not possible (17 implants). One wound dehiscence occurred that needed secondary intervention. During follow-up (40 ± 14 months), one implant was lost due to peri-implantitis with an infected osteosynthesis screw. Marginal peri-implant bone loss was 0.65 ± 0.47 mm during this period.ConclusionCalvarial bone is a sound extra-oral donor site when aiming for reconstruction of a large bony defect of the alveolar process of partially dentate patients.

ICS classification system of infected osteosynthesis: Long-term results

The best treatment strategy for infected osteosyntheses is still debated. While hardware removal or eventually early device exchange may be necessary in most of the cases, temporary hardware retention until fracture healing can be a valid alternative option in others. Aim of the present study is to report the long-term results of 215 patients with infected osteosyntheses, treated according to the ICS (Infection, Callus, Stability) classification in two Italian hospitals. Patients classified as ICS Type 1 (N = 83) feature callus progression and hardware stability, in spite of the presence of infection; these patients were treated with suppressive antibiotic therapy coupled with local debridement in 18.1% of the cases, and no hardware removal until bone healing. Type 2 patients (N = 75) are characterized by the presence of infection and hardware stability, but no callus progression; these patients were treated as Type 1 patients, but with additional callus stimulation therapies. Type 3 patients (N = 57), showing infection, no callus progression and loss of hardware stability, underwent removal and exchange of the fixation device. Considering only the initial treatment, performed according to the ICS classification, at a minimum 5 years follow up, 89.3% achieved bone healing and 93.5% did not show infection recurrence. The ICS classification appears as a useful and reliable tool to help standardizing the decision-making process in treating infected osteosynthesis with the most conservative approach.

Reply to comment by Koranda: 99mTc-HMPAO-labelled leucocytes in musculoskeletal infections—the choice of reference tissue for a semiquantitative analysis

Dear Sir, We thank Dr. Koranda for his comment and questions [1] regarding our article aimed at defining the best image acquisition protocols and interpretation criteria for white blood cell (WBC) scintigraphy with Tc-HMPAO-labelled leucocytes in musculoskeletal infections [2]. As a conclusion of our retrospective study, we recommend using a dual acquisition protocol with acquisition times of 3–4 h and 20–24 h after reinjection. Acquisition times for the scans have to be corrected for decay of the radionuclide and the images should be displayed with the number of counts and the same intensity scale, making comparisons between images possible without observer bias. Visual analysis, in the majority of cases, is sufficient for diagnosis. Increased uptake or enlargement of area of uptake over time is considered positive for an infection, whereas a decreased or stable uptake over time is considered negative for an infection. In all major subgroups of patients (suspected infected hip prosthesis, suspected infected knee prosthesis, suspected osteomyelitis, suspected infected osteosynthesis), visual analysis showed better sensitivity, specificity and diagnostic accuracy compared to semiquantitative analysis. However, in cases where visual analysis does not allow an easy interpretation and diagnosis, there is an added value of applying a semiquantitative analysis. Increase of a lesion to reference tissue (L/R) ratio over time is considered positive for an infection. Dr. Koranda questioned the reference sites that were used for the semiquantitative analysis. In our study we compared four different reference regions: contralateral tissue, ipsilateral bone marrow, contralateral bone marrow and the anterior superior iliac crest. However, calculation of background in all regions was not always possible. In some cases the anterior superior iliac crest was not in the field of view, and sometimes also bone marrow (ipsior contralateral) was not visible. We were able to calculate (in a total of 297 patients) L/R ratios in 285 patients for contralateral tissue, in 169 patients for ipsilateral bone marrow, in 177 patients for contralateral bone marrow and in 73 patients only for the anterior superior iliac crest. Overall, the diagnostic accuracy for the contralateral tissue was the best (84.2 %) as compared to 81.7 % for ipsilateral bone marrow, 76.8 % for contralateral bone marrow and 82.2 % for the anterior superior iliac crest. Dr. Koranda states that the diagnostic accuracy of the method using the anterior superior iliac crest as a reference region was determined in the subgroup of patients with infected hip prosthesis only and that the diagnostic accuracy of all other methods was calculated for larger groups of patients [1]. Indeed, in the infected hip prosthesis subgroup all four reference regions were calculated and, of course, in this group we were able to calculate a relatively high number of anterior superior iliac crests as reference tissue compared to the other groups, since this reference region was mostly included in the field of view. However, even in eight patients with a suspected infected hip prosthesis, the anterior superior iliac crest was not in the field of view or was only visible with superimposed bowel uptake. A. W. J. M. Glaudemans (*) : E. F. J. de Vries :R. H. J. A. Slart : R. A. J. O. Dierckx :A. Signore Department of Nuclear Medicine andMolecular Imaging, University of Groningen, University Medical Center Groningen, PO Box 30.001, 9700 RB Groningen, The Netherlands e-mail: a.w.j.m.glaudemans@umcg.nl

Anaesthesia and orphan disease

Anaesthesia and orphan disease

A large retrospective single-centre study to define the best image acquisition protocols and interpretation criteria for white blood cell scintigraphy with 99mTc-HMPAO-labelled leucocytes in musculoskeletal infections

The diagnosis of infection is often based on clinical, pathological and microbiological results. However, these investigations lack specificity. White blood cell (WBC) scintigraphy is considered the gold standard nuclear imaging technique for diagnosing infections in bone and soft tissues (except spondylodiscitis). However, image acquisition and interpretation criteria differ amongst centres throughout the world, leading to differences in reported results. The aim of this study was to identify the most accurate WBC scintigraphy acquisition and interpretation protocols for diagnosis of bone and soft tissue infections. Included in this retrospective study were 297 patients with suspected bone or soft tissue infection who underwent WBC scintigraphy with (99m)Tc-HMPAO-labelled leucocytes between 2009 and 2012. Sensitivity, specificity, accuracy, and positive and negative predictive values of WBC scintigraphy were determined for two different dual time point acquisition protocols (fixed-time acquisition and time decay-corrected acquisition) and five image interpretation methods (visual and semiquantitative with four different reference regions of interest). Final diagnosis was based on pathological and microbiological reports, and when these were not available, on clinical follow-up of at least 6 months. The best acquisition protocol was 4 h and 20 - 24 h dual time-point acquisition with time decay-corrected acquisition. When using this acquisition protocol, visual qualitative interpretation led to a sensitivity of 85.1 %, a specificity of 97.1 %, a diagnostic accuracy of 94.5 %, a positive predictive value of 88.8 % and a negative predictive value of 95.9 %. For semiquantitative analysis, the best results were found when lesion-to-reference ratios were calculated with the contralateral side as the reference tissue, except for osteomyelitis and infected osteosynthesis, for which the contralateral bone marrow was found to be the best reference tissue. Results of the semiquantitative analyses per se were not better than for visual analysis. In the optimal analysis protocol, scans are first visually evaluated, and if this gives equivocal results, semiquantitative analysis is performed. This strategy resulted in an improved sensitivity of 97.9 %, a specificity of 91.8 % and a diagnostic accuracy of 93.1 %. WBC scintigraphy for bone and soft-tissue infection is best performed using a dual acquisition protocol at 4 h and at 20-24 h after injection, in which the acquisition time of the scans is corrected for decay. In most patients, visual analysis is sufficient and leads to high diagnostic accuracy. When interpretation by visual analysis is inconclusive, semiquantitative analysis adds accuracy. Based on our results, we propose a flow chart for analysing WBC scintigraphy in musculoskeletal infections.

Treatment and complications of mandibular fractures: A 10-year analysis

The surgical treatment and complications of patients with mandibular fractures in Amsterdam over a period of 10 years are analysed. Between January 2000 and January 2009 225 patients were surgically treated for a mandibular fracture (mean age of 32.6 (SD±14.6) years). A total of 426 fracture lines were identified. Of 213 dentate patients 29 patients were treated primarily with intermaxillary fixation (IMF). IMF combined with osteosynthesis was performed on 99 patients. Seventy-nine patients received IMF only per-operatively to make open reduction and internal fixation (ORIF) possible. Of 12 edentulous patients three patients were treated with Gunning splints. Nine patients were treated by manual reduction and internal fixation. A total of 1965 screws and 442 plates were used. Sixty (26.7%) patients presented with complications, including (transient) hyposensibility of the lip and chin (34 patients), dysocclusion (15 patients), infected osteosynthesis material (six patients) and temporomandibular dysfunction (five patients). Four patients needed surgical retreatment for correction of a dysocclusion. The results of this report are partly in line with other studies and provide important data for improving the treatment of the fractured mandible.

Ilizarov methodology for infected non union of the Tibia: Classic circular transfixion wire assembly vs. hybrid assembly.

Introduction:Conventional wire fixation of Ilizarov rings often fails to provide 90-90 configuration because of vital structures, which is essential for optimum stability. Hybrid assembly with half pins is an alternative. The aim of this study is to compare the results of Hybrid assembly with that of conventional classic circular transfixion wire Ilizarov assembly in 50 cases of infected nonunion of tibia between 1994 and 2003.Materials and Methods:This study includes two groups with 25 patients in each group: Group (A) conventional Ilizarov assembly and Group (B) hybrid Ilizarov assembly. Thirty-five cases developed infected nonunion following road traffic accidents while others after fall (6) bullet injury (4), infected osteosynthesis (3) and assault (2). There were 45 males and five females with mean age (18 to 56 years). All active cases (n=28) were treated by debridement including removal of implants in infected osteosynthesis. Twenty out of 22 cases in the quiescent group (non draining for last three consecutive months) were treated without open debridement; only two cases required open debridement for various reasons. All the cases were finally treated as atrophic aseptic nonunion with bone defect and were classified according to ASAMI.Type B1: length of the limb maintained with bone gap (14 cases in both Group A and B) and Type B3: combined shortening with defect (five and seven cases in Group A and B respectively), were treated by bifocal osteosynthesis. Only one case in the B3 group was treated by trifocal osteosynthesis to shorten the time. Type B2: segments in contact with limb shortening (total nine cases; five and four cases in Group A and B respectively) with shortening up to 2 cm (total five cases) were treated with monofocal osteosynthesis while shortening up to 5 cm and beyond (total four cases) were treated with bifocal osteosynthesis.Results:The cases were followed up for two to six years and the results were evaluated by Paley criteria of bony results (union, infection, deformity and leg-length discrepancy) and Functional Results (significant limp, equinus rigidity of the ankle, soft-tissue dystrophy, pain and inactivity). In both the groups, 24 cases out of 25, had excellent to good bony result with Group B having twice more excellent result than Group A. Functional results were found to be similar in both the groups. Although persistence of infection and Grade III pin tract infection (PTI) were slightly higher in Group B, complications like delayed consolidation of regenerate, refracture, deformity and aneurysm of vessel were less in this group.Discussion and Conclusion:Ilizarov methodology produced a satisfactory result in infected nonunion of the tibia. Hybrid assembly was a fruitful advancement in the Ilizarov armamentarium. The results were comparable to Conventional assembly in terms of docking site problems, corticotomy site problems, PTIs and other problems.

Use of Antibiotic-Loaded Polymethyl Methacrylate Beads in the Management of Musculoskeletal Sepsis — A Retrospective Study

To assess the use of antibiotic-loaded polymethyl methacrylate beads in the management of chronic osteomyelitis of different aetiologies: infected osteosynthesis, infected open fractures, and haematogenous osteomyelitis. Records of 49 patients with chronic osteomyelitis who were treated at Department of Orthopaedics, Kasturba Medical College, from 1995 to 1999 were studied retrospectively. The diagnosis of chronic osteomyelitis was made on the basis of clinical and radiographic features. Of the 49 patients, 4 had haematogenous osteomyelitis, which later proved to be tuberculosis, and were thus excluded. Antibiotic-loaded acrylic beads were implanted in the remaining patients after thorough debridement. The implant was removed primarily in 16 patients with infected osteosynthesis, who then underwent decompression and sequestrectomy. All wounds were closed primarily. Peri-operative antibiotics were given for 7 days. Beads were removed at the end of 3 weeks followed by bone grafting in 26 patients. Patients were followed up for an average period of 3.7 years. The infective organisms were sensitive to gentamycin in 26 cases and resistant in 19 cases; 14 cases were sensitive to cefuroxime, 11 to cloxacillin, 8 to ampicillin, and 5 to cotrimoxazole. Seven cases were resistant to all antibiotics tested. Of the 19 patients with gentamycin-resistant infection, only one had a poor result. No adverse systemic side-effects such as ototoxicity or nephrotoxicity were seen. Infection did not recur in 39 patients, but 6 patients had low-grade persistent infection at the last follow-up visit. In chronic infections, especially those following osteosynthesis, antibiotic beads are a valuable adjuvant. The most valuable advantage is that the wound can be closed primarily, thereby reducing the incidence of nosocomial infections and requirement of nursing care.

Antibiotic Bead Chains

Gentamicin-PMMA chains are an effective drug delivery system for local antibiotic therapy in bone and soft-tissue infections. The gentamicin concentrations at the site of infection are far higher than after systemic application of the same antibiotic and far above the minimal inhibitory concentrations of most common pathogens. Because of the very low concentrations in the serum and urine after implantation of the antibiotic bead chains, toxic side effects are not to be feared. Radical debridement with removal of all sequestrated bone fragments and removal of all alloplastic implants is mandatory before implantation of gentamicin-PMMA chains into the infected bone cavity. Primary wound closure is necessary to achieve high local concentrations. The chains can be used for temporary or permanent filling of osteomyelitic cavities. Guidelines are given for the clinical application in sequestrating osteomyelitis, infected osteosynthesis, and infected pseudarthrosis. There are distinct advantages of this new form of antibiotic therapy in chronic osteomyelitis, such as increased patient comfort by primary wound closure, no need for prolonged systemic antibiotic therapy with toxic side effects, no irrigation-suction-drainage, early ambulation, shortening of hospitalization, and reduced cost.