The Microbiological Profile and Antibiotic Susceptibility of Fracture Related Infections in a Low Resource Setting Differ from High Resource Settings: A Cohort Study from Cameroon.

Fracture-related infection (FRI) is a common and devastating complication of orthopedic trauma in all settings. Data on the microbiological profile and susceptibility of FRI to antibiotics in low-income countries are scarce. Therefore, this study aimed to investigate the microbial patterns and antimicrobial susceptibility of FRI in a sub-Saharan African setting in order to provide guidance for the formulation of evidence-based empirical antimicrobial regimens. We conducted a retrospective analysis of patients treated for FRI with deep tissue sampling for microbiological culture from January 2016 to August 2023 in four tertiary-level hospitals in Yaoundé, Cameroon. There were 246 infection episodes in 217 patients. Cultures were positive in 209 (84.9%) cases and polymicrobial in 109 (44.3%) cases. A total of 363 microorganisms from 71 different species were identified, of which 239 (65.8%) were Gram-negative. The most commonly isolated pathogens were Staphylococcus aureus (n = 69; 19%), Enterobacter cloacae (n = 43; 11.8%), Klebsiella pneumoniae (n = 35; 9.6%), Escherichia coli (n = 35; 9.6%), and Pseudomonas aeruginosa (n = 27; 7.4%). Coagulase-negative staphylococci (CoNS) were isolated in only 21 (5.9%) cases. Gram-negative bacteria accounted for the majority of the infections in early (70.9%) and delayed (73.2%) FRI, but Gram-positive bacteria were prevalent in late FRI (51.7%) (p < 0.001). Polymicrobial infections were more frequent in the early (55.9%) and delayed (41.9%) groups than in the late group (27.6%) (p < 0.001). Apart from Staphylococcus aureus, there was no significant difference in the proportions of causative pathogens between early, delayed, and late FRI. This study found striking resistance rates of bacteria to commonly used antibiotics. MRSA accounted for 63% of cases. The most effective antibiotics for all Gram-positive bacteria were linezolid (96.4%), vancomycin (92.5%), clindamycin (85.3%), and fucidic acid (89.4%). For Gram-negative bacteria, only three antibiotics displayed a sensitivity >50%: amikacin (80.4%), imipenem (74.4%), and piperacillin + tazobactam (57%). The most effective empirical antibiotic therapy (with local availability) was the combination of vancomycin and amikacin or vancomycin and imipenem. In contrast to the literature from high-resource settings, this study revealed that in a sub-Saharan African context, Gram-negative bacteria are the most common causative microorganisms of FRI. This study revealed striking resistance rates to commonly used antibiotics, which will require urgent action to prevent antimicrobial resistance in low and middle-income countries.

Predictive factors for fracture-related infection in open tibial fractures in a Sub-Saharan African setting.

INTRODUCTION: The management of open tibial fractures (OTF) is challenging in low and middle-income countries (LMICs) where appropriate human resources and infrastructure (including equipment, implants and surgical supplies) are not readily available and medical care is not readily accessible. OTF are not rarely associated with a subsequent fracture-related infection (FRI), which is one of the most devastating and difficult to cure complications in orthopaedic trauma care. The aim of this study was to determine the rate and the predictive factors of FRI in OTF in a limited-resource setting of sub-Saharan Africa. METHODS: Patients with OTF who underwent surgery from July 2015 to December 2020 and followed-up for at least 12 months in a tertiary care teaching hospital in Yaoundé (Cameroon) were retrospectively investigated. Diagnosis of FRI was based on the confirmatory criteria of the International FRI Consensus definition. All patients with bone infections, occurring at any time point during follow-up, were included. Logistic regression was used to determine the predictive factors for FRI. RESULTS: One hundred and five patients with OTF were studied. With a mean follow-up period of 29.5 ± 16.6 months, 33 patients (31.4%) presented with FRI. Gustilo-Anderson type of OTF, compliance with antibiotics, blood transfusion, time to first washing of the wounds and method of bone fixation were factors associated with the occurrence of FRI. In multivariable logistic regression, 6-hours delay to first washing of the wounds (OR=8.07, 95% CI: 1.43-45.31, p = 0.01), and compliance with antibiotics (OR=11.33, 95%CI: 1.11-115.6, p = 0.04) were the only independent predictors of FRI. CONCLUSION: The overall rate of FRI in open tibial fracture is still high in the sub-Saharan African context. For similar low-resources settings, this study supports the recommendations (1) to perform a very early washing-dressing-splinting of OTF on admission of the patient, (2) to administer antibiotics early, and (3) to perform surgery as soon as reasonably possible, once appropriate personnel, equipment, implants and surgical supplies are available.

Locally developed external fixators as definitive treatment of open tibia diaphyseal fractures: a clinical prospective study conducted in Ivory Coast.

BACKGROUND: This study sought to evaluate the effectiveness of locally developed external fixators (LDEF) as definitive treatment for open tibia diaphyseal fractures (OTDF) in Ivory Coast. METHODS: Gustilo I, II, and IIIA OTDFs of patients admitted within 24 hours of injury were prospectively included and treated with LDEF. The rates of union, mal-union, septic complications, as well as the functional results were assessed, in addition to the LDEF construct's integrity. Predictive factors of failure or poor results were assessed. RESULTS: Overall, 40 OTDF patients were admitted within 24 hours of injury. Gustilo I, II, and IIIA fractures were observed in three, 13, and 24 patients, respectively. Uneventful fracture healing was obtained in 29 cases, with an average union time of 8.47 months. Mal-union and non-union were registered in three and four cases, respectively. Pin-track infection (PTI) was observed in 13 cases and deep infection in seven. Infection resolved in all patients except four, who developed chronic osteomyelitis. None of the non-unions were associated with an infection. The overall functional result was satisfactory in 32 patients. PTI was the only predictive factor for chronic infection. Biplanar frames, when compared to monoplanar constructs, were associated with a significantly improved functional outcome. CONCLUSION: LDEF improved significantly the OTDF management, as it provided better stability and superior fracture healing rates than what is observed with the standard of care in the same environment. PTI remains an essential problem but with, hopefully, limited negative consequences.

Early posttraumatic ankle osteoarthritis following ankle fracture-dislocations in a sub-Saharan African setting.

INTRODUCTION: Ankle fracture-dislocation (AFD) represents a major threat to the joint and a potential source of complication and functional disability. This study was performed to assess the outcome of AFD in a resource-limited setting and factors associated with the posttraumatic ankle osteoarthritis (PTAOA). We hypothesized that conservative treatment after AFD was associated with higher risk of PTAOA compared to surgical treatment. PATIENTS AND METHODS: Data from 52 consecutive patients (mean age 37.2±11.1years, with 57.7% n=30, males) who were treated and followed in a teaching hospital for AFD during a period of six years were collected. Forty-four of these patients were obtained at the time of the study for a retrospective evaluation. Functional outcome was assessed using the American Orthopaedic Foot and Ankle Society (AOFAS), ankle-hindfoot scale, and the patient's global satisfaction index. Radiographs were performed and analyzed for PTAOA. Logistic regression was used to determine factors associated with the presence of PTAOA. RESULTS: PTAOA was found in 19 (43.2%) patients after an average follow-up period of 27.2±18.3months. Anatomic fracture reduction was achieved in 22 (50%) patients, while the talus was centered in the mortise in 30 (68.2%) patients. Despite these poor anatomical results, the clinical outcome was good to excellent in 33 (75%) patients, and 88.6% was satisfied or very satisfied. Factors associated with the presence of PTAOA were the non-anatomical reduction (OR=11.07; p=0.007, 95% CI: 2.096-58.77) and the time elapsed since trauma (OR=1.073; p=0.007, 95% CI: 1.109-1.129). CONCLUSION: This study indicates that AFDs are associated with high rate of early and severe PTAOA. Non-anatomical realignment and a delay since trauma were positive predictors of PTAOA. There was no difference regarding the occurrence of PTAOA after AFD whatever the type of treatment, surgical or conservative. LEVEL OF EVIDENCE: IV; retrospective cohort study.

Treatment of open tibia fractures in Sub-Saharan African countries : a systematic review.

Open tibia fracture (OTF) treatment is well documented in developed countries. Yet, this fracture pattern remains challenging because it is associated with an increased risk of infection and delayed union, particularly in case of Gustilo III B and C open fractures. Since access to healthcare is limited in Sub- Saharan African countries, this paper explores the results of OTF management in this setting. A systematic review of the literature was conducted using current databases such as MEDLINE, Cochrane, EMBASE, PubMed, ScienceDirect, Scopus, and Google Scholar in order to identify prospective studies with cohorts of patients treated for OTF. Studies were included based on predefined inclusion and exclusion criteria. The quality of studies was analyzed by the Coleman Methodology Score (CMS). Eight papers met the inclusion criteria and had an average CMS of 70 (range 54-73). The most common treatment was non-operative management of the fracture with cast immobilization (67%). Gustilo Type II and III fractures were associated with a higher risk of complications. The infection rate was 30%. Malunion, chronic osteomyelitis and nonunion were observed in 14.5%, 12.3%, and 7% of the cases, respectively. More complications were observed with non-operative treatment (cast immobilization) than with surgical fixation. Although the surgical environment does not allow for internal fixation, poor results of non-operative management of open fractures should lead to the introduction of trainings on the proper use of external fixators. It is also advisable to support the development of locally produced external devices that utilize local source materials, which would make external fixation available at a reasonable cost.

A Comparison of Genicular Nerve Blockade With Corticosteroids Using Either Classical Anatomical Targets vs Revised Targets for Pain and Function in Knee Osteoarthritis: A Double-Blind, Randomized Controlled Trial.

OBJECTIVE: Compare the effectiveness of genicular nerve blockade (GNB) using classical anatomical targets (CT) versus revised targets (RT) in patients suffering from chronic knee osteoarthritis pain. DESIGN: Double-blinded randomized controlled trial. SETTING: Pain medicine center of a teaching hospital. METHODS: We randomly assigned 55 patients with chronic knee osteoarthritis pain to receive a GNB (using a fluid mixture of 2 mL: lidocaine 1% + 20 mg triamcinolone) with either classical targets (CT-group, n = 28) or revised targets (RT-group, n = 27). Numeric rating pain scale (NRS), Oxford knee score (OKS), Western Ontario and McMaster Universities osteoarthritis index score (WOMAC), Quantitative analgesic questionnaire (QAQ) and global perceived effects were assessed at baseline, and at 1-hour, 24-hours, 1, 4, and 12 weeks post-intervention. RESULTS: The RT-group showed greater reduction in NRS mean score at 1-hour post-intervention (2.4 ± 2.1 vs 0.4 ± 0.9, 95% confidence interval (CI) [.0-.8] vs [1.6-3.2], P < .001). The proportion of patients achieving more than 50% knee pain reduction was higher in the RT-group at each follow up interval, yet these differences were statistically significant only at 1-hour post intervention (82.1% [95% CI = 63.1-93.9] vs 100% [95% CI = 97.2-100] P = .02). Both protocols resulted in significant pain reduction and joint function improvement up to 12 weeks post-intervention. CONCLUSIONS: The revised technique allowed more pain relief as well as greater proportion of successful responders at 1-hour post intervention. The large volume injected during therapeutic GNB could have compensated the lack of precision of the classical anatomical targets, mitigating differences in outcomes between both techniques.

Anatomical study of the descending genicular artery and implications for image-guided interventions for knee pain.

INTRODUCTION: The descending genicular artery (DGA) has recently been mentioned as accompanying some nerves in the medial aspect of the knee joint. This could be clinically relevant as the arteries could serve as landmarks for accurate nerve capture during ultrasound-guided nerve blockade or ablation. The aim of this cadaveric study was to investigate the anatomical distribution of the DGA, assess the nerves running alongside its branches, and discuss the implications for regional anesthesia and knee pain interventions. METHODS: We dissected the femoral artery (FA) all along its course to identify the origin of the DGA, from which we carefully dissected all branches, in 27 fresh-frozen human specimens. Simultaneously, we systematically dissected the nerves supplying the medial aspect of the knee from proximally to distally and identified those running alongside the branches of the DGA. The surrounding anatomical landmarks were identified and measurements were recorded. RESULTS: The DGA was found in all specimens, arising from the FA 130.5 ± 17.5 mm (mean ± SD) proximally to the knee joint line. Seven distribution patterns of the DGA were observed. We found three consistent branches from the DGA running alongside their corresponding nerves at the level of the medial aspect of the knee: the artery of the superior-medial genicular nerve, the artery of the infrapatellar branch of the saphenous nerve, and the saphenous branch of the DGA. CONCLUSION: The consistent arteries and surrounding landmarks found in this study could help to improve the capture of the targeted nerves during ultrasound-guided interventions.

Validation of a new protocol for ultrasound-guided genicular nerve radiofrequency ablation with accurate anatomical targets: cadaveric study.

INTRODUCTION: Ultrasound (US)-guided radiofrequency ablation (RFA) of genicular nerves (GNs) is increasingly performed to manage chronic knee pain. The anatomical foundations supporting the choice of original targets for US-guided GN-RFA have been thoroughly improved by recent anatomical studies. Therefore, this study aimed to provide a new protocol with revised anatomical targets for US-guided GN-RFA and to assess their accuracy in a cadaveric model. MATERIALS AND METHODS: Fourteen fresh-frozen cadaveric knees were used. After a pilot study with 4 knees, five consistent nerves were targeted in the other 10 knees with revised anatomical landmarks: superior medial genicular nerve (SMGN), superior lateral genicular nerve (SLGN), inferior medial genicular nerve (IMGN), recurrent fibular nerve (RFN) and the infrapatellar branch of the saphenous nerve (IPBSN). For each nerve, the lumen of radiofrequency (RF) cannula was prefilled with non-diffusible black paint, and then the cannula was inserted at the target site under US guidance. After US verification of correct placement, the stylet was introduced in the cannula to create a limited black mark on the tissues at the top of the active tip. Anatomical dissection was performed to assess for accuracy. RESULTS: The proportion of nerves directly found in contact with the black mark was 7/10, 8/10, 10/10 and 9/10 for the SMGN, SLGN, IMGN and RFN, respectively. The proportions of nerve captured by the theoretical largest monopolar RF lesions were 100% for the SMGN, IMGN and RFN, and IPBSN and 95% for SLGN. The mean distances from the center of the black mark to the targeted nerve were 2.1±2.2 mm, 1.0±1.4 mm, 0.75±1.1 mm and 2.4±4.5 mm for the SMGN, SLGN, IMGN and RFN, respectively. CONCLUSION: US-guided GN-RFA with revised anatomical targets resulted in accurate capture of the five targeted nerves. This protocol provides precise sensory denervation of a larger panel of nerves, targeting those whose constancy regarding anatomical location has been clearly demonstrated. It is expected to improve the clinical outcomes.

Lower limb kinematics improvement after genicular nerve blockade in patients with knee osteoarthritis: a milestone study using inertial sensors.

BACKGROUND: Genicular nerve blockade is a possible treatment for patients with knee osteoarthritis. Pain relief and improvement in functioning is expected. This procedure could be of major interest for patients in low-income countries where total knee arthroplasty is not available for the population. This study aims at assessing the immediate benefits on pain, gait, and stairs kinematics after a genicular nerve blockade in patients suffering from knee osteoarthritis in Cameroun. METHODS: A prospective study was carried out on 26 subjects in Cameroun. A genicular nerve blockade was performed on 14 women with painful knee osteoarthritis grade 2-4. Lower limb joint angles were recorded with inertial sensors before and 1 h after injection. Patient-reported outcomes of pain and perceived difficulty were collected, as well as 10 m and 6 min walking tests. A reliability analysis of inertial sensors was performed on a sample of 12 healthy subjects by calculating the intraclass correlation coefficient and the standard error of measurement. RESULTS: Pain and perceived difficulty decreased significantly (p < 0.001). Cadence increased significantly in stairs climbing (upstairs: + 7.7 steps/min; downstairs: + 7.6 steps/min). There was an improvement for hip sagittal range of motion during gait (+ 9.3°) and pelvis transverse range of motion in walking upstairs (- 3.3°). Angular speed range of the knee in the sagittal plane and of the hip in the frontal plane increased significantly in stairs descent (+ 53.7°/s, + 94.5°/s). CONCLUSIONS: This study quantified improvement of gait and stair climbing immediately after a genicular nerve blockade in patients suffering from knee OA in Cameroon. This is the first study objectifying this effect, through wearable sensors. TRIAL REGISTRATION: Pan African Clinical Trial Registry, PACTR202004822698484 . Registered 28 March 2020 - Retrospectively registered.

Biomechanical study of a low-cost external fixator for diaphyseal fractures of long bones.

BACKGROUND: External fixation improves open fracture management in emerging countries. However, sophisticated models are often expensive and unavailable. We assessed the biomechanical properties of a low-cost external fixation system in comparison with the Hoffmann® 3 system, as a reference. METHODS: Transversal, oblique, and comminuted fractures were created in the diaphysis of tibia sawbones. Six external fixators were tested in three modes of loading-axial compression, medio-lateral (ML) bending, and torsion-in order to determine construction stiffness. The fixator construct implies two uniplanar (UUEF1, UUEF2) depending the pin-rods fixation system and two biplanar (UBEF1, UBEF2) designs based on different bar to bar connections. The designed low-cost fixators were compared to a Hoffmann® 3 fixator single rod (H3-SR) and double rod (H3-DR). Twenty-seven constructs were stabilized with UUEF1, UUEF2, and H3-SR (nine constructs each). Nine constructs were stabilized with UBEF1, UBEF2, and H3-DR (three constructs each). RESULTS: UUEF2 was significantly stiffer than H3-SR (p < 0.001) in axial compression for oblique fractures and UUEF1 was significantly stiffer than H3-SR (p = 0.009) in ML bending for transversal fractures. Both UUEFs were significantly stiffer than H3-SR in axial compression and torsion (p < 0.05), and inferior to H3-SR in ML bending, for comminuted fractures. In the same fracture pattern, UBEFs were significantly stiffer than H3-DR (p = 0.001) in axial compression and torsion, while only UBEF1 was significantly stiffer than H3-DR in ML bending (p = 0.013). CONCLUSIONS: The results demonstrated that the stiffness of the UUEF and UBEF device compares to the reference fixator and may be helpful in maintaining fracture reduction. Fatigue testing and clinical assessment must be conducted to ensure that the objective of bone healing is achievable with such low-cost devices.

Current versus revised anatomical targets for genicular nerve blockade and radiofrequency ablation: evidence from a cadaveric model.

INTRODUCTION: Recent studies have proposed revised anatomical targets to improve accuracy of genicular nerve (GN) radiofrequency ablation (RFA). This study aims to compare the accuracy of classical and revised techniques for fluoroscopic-guided GN-RFA in cadaveric models. MATERIALS AND METHODS: Fourteen knees from seven fresh frozen human cadavers were included in this study. For each cadaver, RF cannulas were placed to capture the GN according to the current targets in one knee, and the revised targets in the other knee, randomly. The stylet was removed from the cannula, plunged into non-diffusible black paint, and reintroduced entirely in the cannula, to create a limited black spot on the tissues at the top of the active tip. Anatomical dissection was performed, and the accuracy of both techniques was compared. RESULTS: The mean distance from the top of the active tip to the nerve was significantly lower with revised than current targets for the superior-medial GN (0.7 mm vs 17.8 mm, p=0.01) and the descending branch of the superior-lateral GN (3.7 mm vs 24.4 mm, p=0.02). In both superior-medial GN and superior-lateral GN, the accuracy rate was higher with revised than current targets: 100% vs 0% and 64% vs 35%, respectively. In addition, the accuracy of revised targets for the recurrent fibular nerve and the infrapatellar branch of saphenous nerve was 100%. CONCLUSION: This study demonstrates that the revised targets are more accurate than the current targets for GN-RFA.

Accuracy of fluoroscopic-guided genicular nerve blockade: a need for revisiting anatomical landmarks.

BACKGROUND AND OBJECTIVES: Genicular nerve blockade (GNB) and radiofrequency ablation (RFA) have recently emerged as treatment options for patients with chronic knee pain. However, an increasing number of anatomical studies and systematic reviews concluded that the anatomical basis for needle placement was unclear, incomplete and somewhat inaccurate. This study was designed to assess the accuracy of updated anatomical landmarks for fluoroscopy-guided blockade of the consistent genicular nerves in a cadaveric model. METHODS: Based on a comprehensive review of recent anatomical studies and prior dissection of 21 fresh cadaver knees, we defined bony landmarks with high likelihood of successful ablation of the five consistent genicular nerves (GN). We tested the accuracy of GNBs using the above-stated anatomical landmarks in 10 intact fresh cadaveric knees. Needle placement was guided by fluoroscopy and 0.5 mL of 0.1% methylene blue was injected at the site of each nerve. The knees were subsequently dissected to assess the accuracy of the injections. If the nerve was dyed with blue ink, the placement was considered accurate. RESULTS: The accuracy of our injections was 100% for the superior medial genicular nerve, inferior medial GN, infrapatellar branch of saphenous nerve and recurrent fibular nerve. The superior lateral GN was dyed in 90% of specimens. CONCLUSION: This study provides physicians with precise anatomical landmarks for the five consistent GN for fluoroscopic-guided GNB. Our revised technique, which targets more nerves with increased accuracy, could potentially lead to improved therapeutic benefits on chronic knee pain.

Distribution of sensory nerves supplying the knee joint capsule and implications for genicular blockade and radiofrequency ablation: an anatomical study.

BACKGROUND: Despite their emerging therapeutic relevance, there are many discrepancies in anatomical description and terminology of the articular nerves supplying the human knee capsule. This cadaveric study aimed to determine their origin, trajectory, relationship and landmarks for therapeutic purpose. METHODS: We dissected 21 lower limbs from 21 cadavers, to investigate the anatomical distribution of all the articular nerves supplying the knee joint capsule. We identified constant genicular nerves according to their anatomical landmarks at their entering point to knee capsule and inserted Kirschner wires through the nerves in underlying bone at those target points. Measurements were taken, and both antero-posterior and lateral radiographs were obtained. RESULTS: The nerve to vastus medialis, saphenous nerve, anterior branch of obturator nerve and a branch from sciatic nerve provide substantial innervation to the medial knee capsule and retinaculum. The sciatic nerve and the nerve to the vastus lateralis supply sensory innervation to the supero-lateral aspect of the knee joint while the fibular nerve supplies its infero-lateral quadrant. Tibial nerve and posterior branch of obturator nerve supply posterior aspect of knee capsule. According to our findings, five constant genicular nerves with accurate landmarks could be targeted for therapeutic purpose. CONCLUSION: The pattern of distribution of sensitive nerves supplying the knee joint capsule allows accurate and safe targeting of five constant genicular nerves for therapeutic purpose. This study provides robust anatomical foundations for genicular nerve blockade and radiofrequency ablation.

Association of academic performance of premedical students to satisfaction and engagement in a short training program: a cross sectional study presenting gender differences.

BACKGROUND: It is important that students have a high academic engagement and satisfaction in order to have good academic achievement. No study measures association of these elements in a short training program. This study aimed to measure the correlation between academic achievement, satisfaction and engagement dimensions in a short training program among premedical students. METHODS: We carried out a cross sectional study, in August 2013, at Cercle d'Etudiants, Ingénieurs, Médecins et Professeurs de Lycée pour le Triomphe de l'Excellence (CEMPLEX) training center, a center which prepares students for the national common entrance examination into medical schools in Cameroon. We included all students attending this training center during last examination period. They were asked to fill out a questionnaire on paper. Academic engagement was measured using three dimensions: vigor, dedication and absorption. Satisfaction to lessons, for each learning subject was collected. Academic achievement was calculated using mean of the score of all learning subjects affected with their coefficient. Pearson coefficient (r) and multiple regression models were used to measure association. A p value < 0.05 was statistically significant. RESULTS: In total, 180 students were analyzed. In univariate linear analysis, we found correlation with academic achievement for vigor (r = 0.338, p = 0.006) and dedication (r = 0.287, p = 0.021) only in male students. In multiple regression linear analysis, academic engagement and satisfaction were correlated to academic achievement only in male students (R2 = 0.159, p = 0.035). No correlation was found in female students and in all students. The independent variables (vigor, dedication, absorption and satisfaction) explained 6.8-24.3% of the variance of academic achievement. CONCLUSION: It is only in male students that academic engagement and satisfaction to lessons are correlated to academic achievement in this short training program for premedical students and this correlation is weak.