Clinical Outcome following Management of Severe Osteomyelitis due to Pin Site Infection.

Aim: This study has investigated cases of pin site infection (PSI) which required surgery for persistent osteomyelitis (OM) despite pin removal. Materials and methods: Patients requiring surgery for OM after PSI between 2011 and 2021 were included in this retrospective cohort study. Single-stage surgery was performed in accordance with a protocol at one institution. This involved deep sampling, debridement, implantation of local antibiotics, culture-specific systemic antibiotics and soft tissue closure. A successful outcome was defined as an infection-free interval of at least 24 months following surgery. Results: Twenty-seven patients were identified (the sites were 22 tibias, 2 humeri, 2 calcanei, 1 radius); about 85% of them were males with a median age of 53.9 years. The majority of infections (21/27) followed fracture treatment. Fifteen patients were classified as BACH uncomplicated and 12 were BACH complex. Staphylococci were the most common pathogens, polymicrobial infections were detected in five cases (19%). Seven patients required flap coverage which was performed in the same operation.After a median of 3.99 years (2.00-8.05) follow-up, all patients remained infection free at the site of the former OM. Wound leakage after local antibiotic treatment was seen in 3/27 (11.1%) cases but did not require further treatment. Conclusion: Osteomyelitis after PSI is uncommon but has major implications for the patient as 7 patients needed flap coverage. This reinforces the need for careful pin placement and pin site care to prevent deep infection. These infections were treated in accordance with a protocol and were not managed simply by curettage. All patients treated in this manner remained infection-free after a minimum follow-up of 2 years suggesting that this protocol is effective. Clinical significance: Pin site infection is a very common complication in external fixation. The sequela of a chronic pin site OM is rare but the implications to the patient are huge. In this series, more than a quarter of patients required flap coverage as part of the treatment of the deep infection. How to cite this article: Frank FA, Pomeroy E, Hotchen AJ, et al. Clinical Outcome following Management of Severe Osteomyelitis due to Pin Site Infection. Strategies Trauma Limb Reconstr 2024;19(1):21-25.

A practical definition of pin site infection.

Pin Site Infection (PSI) is the most common complication of external fixation treatment. Several classifications and diagnostic approaches have been used with reported incidences varying widely from 1 to 100 %. The quality of the existing literature is limited by the absence of a definition. This renders comparing literature and developing evidence-based algorithms for prevention, diagnostics, and treatment difficult to impossible. Similar problems were identified with prosthetic joint infection (PJI) and fracture-related infection (FRI) in recent years, resulting in new, validated definitions. PSI is complicated by the complexity of the issue. Numerous factors in PSI need consideration. Factors may be related to the patient, the surgical technique, the pin-bone interface, the pin-skin interface, the choice of external fixation device and/or the material used and its properties. Reliably diagnosing PSI is one of the most pressing issues. New definitions for FRI or PJI have diagnostic criteria which can be either confirmatory or suggestive. Any positive finding of a confirmatory criterion constitutes an infection. Although PSI resembles PJI and FRI, distinct differences are present. The skin is never closed, and bacterial colonization is inevitable along the treatment duration. The external fixator is only temporarily in place; thus, the goal of all measures is to continue the external fixator until the intended indication is reached. This paper proposes the principles of a definition of PSI. This definition is not designed to guide any treatment of PSI. Its purpose is to create common ground for clinical investigations and publishing further research.

Mid- to long-term results of single-stage surgery for patients with chronic osteomyelitis using a bioabsorbable gentamicin-loaded ceramic carrier.

AIMS: Excision of chronic osteomyelitic bone creates a dead space which must be managed to avoid early recurrence of infection. Systemic antibiotics cannot penetrate this space in high concentrations, so local treatment has become an attractive adjunct to surgery. The aim of this study was to present the mid- to long-term results of local treatment with gentamicin in a bioabsorbable ceramic carrier. METHODS: A prospective series of 100 patients with Cierny-Mader Types III and IV chronic ostemyelitis, affecting 105 bones, were treated with a single-stage procedure including debridement, deep tissue sampling, local and systemic antibiotics, stabilization, and immediate skin closure. Chronic osteomyelitis was confirmed using strict diagnostic criteria. The mean follow-up was 6.05 years (4.2 to 8.4). RESULTS: At final follow-up, six patients (six bones) had recurrent infection; thus 94% were infection-free. Three infections recurred in the first year, two in the second year, and one 4.5 years postoperatively. Recurrence was not significantly related to the physiological class of the patient (1/20 Class A (5%) vs 5/80 Class B (6.25%); p = 0.833), nor was it significantly related to the aetiology of the infection, the organisms which were cultured or the presence of nonunion before surgery (1/10 with nonunion (10%) vs 5/90 without nonunion (5.6%); p = 0.570). Organisms with intermediate or high-grade resistance to gentamicin were significantly more likely in polymicrobial infections (9/21; 42.8%) compared with monobacterial osteomyelitis (7/79 (8.9%); p < 0.001). However, recurrence was not significantly more frequent when a resistant organism was present (1/16 for resistant cases (6.25%) vs 5/84 in those with a microbiologically sensitive infection (5.95%); p = 0.958). CONCLUSION: We found that a single-stage protocol, including the use of a high-delivery local antibiotic ceramic carrier, was effective over a period of several years. The method can be used in a wide range of patients, including those with significant comorbidities and an infected nonunion.Cite this article: Bone Joint J 2022;104-B(9):1095-1100.

Can we predict outcome after treatment of long bone osteomyelitis?

AIMS: This study presents patient-reported quality of life (QoL) over the first year following surgical debridement of long bone osteomyelitis. It assesses the bone involvement, antimicrobial options, coverage of soft tissues, and host status (BACH) classification as a prognostic tool and its ability to stratify cases into 'uncomplicated' or 'complex'. METHODS: Patients with long-bone osteomyelitis were identified prospectively between June 2010 and October 2015. All patients underwent surgical debridement in a single-staged procedure at a specialist bone infection unit. Self-reported QoL was assessed prospectively using the three-level EuroQol five-dimension questionnaire (EQ-5D-3L) index score and visual analogue scale (EQ-VAS) at five postoperative time-points (baseline, 14 days, 42 days, 120 days, and 365 days). BACH classification was applied retrospectively by two clinicians blinded to outcome. RESULTS: In total, 71 patients with long-bone osteomyelitis were included. There was significant improvement from time of surgery to one year postoperatively in mean EQ-VAS (58.2 to 78.9; p < 0.001) and mean EQ-5D-3L index scores (0.284 to 0.740; p < 0.001). At one year following surgery, BACH 'uncomplicated' osteomyelitis was associated with better QoL compared to BACH 'complex' osteomyelitis (mean EQ-5D-3L 0.900 vs 0.685; p = 0.020; mean EQ-VAS 87.1 vs 73.6; p = 0.043). Patients with uncomplicated bone involvement (BACH type B1, cavitary) reported higher QoL at all time-points when compared to complex bone involvement (B2, segmental or B3, osteomyelitis involving a joint). Patients with good antimicrobial options (Ax or A1) gave higher outcome scores compared to patients with multidrug-resistant isolates (A2). The need for microvascular tissue transfer (C1 and C2) did not impact significantly on QoL. Patients without major comorbidities (uncomplicated, H1) reported higher QoL compared to those with significant disease (complex, H2). CONCLUSION: Uncomplicated osteomyelitis, as defined by BACH, gave higher self-reported QoL when compared to complex cases. The bone involvement, antimicrobial options, and host status variables were able to stratify patients in terms of QoL. These data can be used to offer prognostic information to patients who are undergoing treatment for long bone osteomyelitis. Cite this article: Bone Joint J 2020;102-B(11):1587-1596.

Can we predict outcome after treatment of long bone osteomyelitis?

AIMS: This study presents patient-reported quality of life (QoL) over the first year following surgical debridement of long bone osteomyelitis. It assesses the bone involvement, antimicrobial options, coverage of soft tissues, and host status (BACH) classification as a prognostic tool and its ability to stratify cases into 'uncomplicated' or 'complex'. METHODS: Patients with long-bone osteomyelitis were identified prospectively between June 2010 and October 2015. All patients underwent surgical debridement in a single-staged procedure at a specialist bone infection unit. Self-reported QoL was assessed prospectively using the three-level EuroQol five-dimension questionnaire (EQ-5D-3L) index score and visual analogue scale (EQ-VAS) at five postoperative time-points (baseline, 14 days, 42 days, 120 days, and 365 days). BACH classification was applied retrospectively by two clinicians blinded to outcome. RESULTS: In total, 71 patients with long-bone osteomyelitis were included. There was significant improvement from time of surgery to one year postoperatively in mean EQ-VAS (58.2 to 78.9; p < 0.001) and mean EQ-5D-3L index scores (0.284 to 0.740; p < 0.001). At one year following surgery, BACH 'uncomplicated' osteomyelitis was associated with better QoL compared to BACH 'complex' osteomyelitis (mean EQ-5D-3L 0.900 vs 0.685; p = 0.020; mean EQ-VAS 87.1 vs 73.6; p = 0.043). Patients with uncomplicated bone involvement (BACH type B1, cavitary) reported higher QoL at all time-points when compared to complex bone involvement (B2, segmental or B3, osteomyelitis involving a joint). Patients with good antimicrobial options (Ax or A1) gave higher outcome scores compared to patients with multidrug-resistant isolates (A2). The need for microvascular tissue transfer (C1 and C2) did not impact significantly on QoL. Patients without major comorbidities (uncomplicated, H1) reported higher QoL compared to those with significant disease (complex, H2). CONCLUSION: Uncomplicated osteomyelitis, as defined by BACH, gave higher self-reported QoL when compared to complex cases. The bone involvement, antimicrobial options, and host status variables were able to stratify patients in terms of QoL. These data can be used to offer prognostic information to patients who are undergoing treatment for long bone osteomyelitis.

Simultaneous debridement, Ilizarov reconstruction and free muscle flaps in the management of complex tibial infection.

Chronic bone infections often present with complex bone and soft tissue loss. Management is difficult and commonly delivered in multiple stages over many months. This study investigated the feasibility and clinical outcomes of reconstruction in one stage. Fifty-seven consecutive patients with chronic osteomyelitis ( n = 27 ) or infected non-union ( n = 30 ) were treated with simultaneous debridement, Ilizarov method and free muscle flap transfer. 41 patients (71.9 %) had systemic co-morbidities (Cierny-Mader group Bs hosts). Infection was confirmed with strict criteria. 48 patients (84.2 %) had segmental defects. The primary outcome was eradication of infection at final follow-up. Secondary outcomes included bone union, flap survival and complications or re-operation related to the reconstruction. Infection was eradicated in 55 / 57 cases (96.5 %) at a mean follow-up of 36 months (range 12-146). No flap failures occurred during distraction but 6 required early anastomotic revision and 3 were not salvageable (flap failure rate 5.3 %). Bony union was achieved in 52 / 57 (91.2 %) with the initial surgery alone. After treatment of the five un-united docking sites, all cases achieved bony union at final follow-up. Simultaneous reconstruction with Ilizarov method and free tissue transfer is safe but requires careful planning and logistic considerations. The outcomes from this study are equivalent or better than those reported after staged surgery.

The BACH classification of long bone osteomyelitis.

OBJECTIVES: The aim of this study was to assess the clinical application of, and optimize the variables used in, the BACH classification of long-bone osteomyelitis. METHODS: A total of 30 clinicians from a variety of specialities classified 20 anonymized cases of long-bone osteomyelitis using BACH. Cases were derived from patients who presented to specialist centres in the United Kingdom between October 2016 and April 2017. Accuracy and Fleiss' kappa (Fκ) were calculated for each variable. Bone involvement (B-variable) was assessed further by nine clinicians who classified ten additional cases of long bone osteomyelitis using a 3D clinical imaging package. Thresholds for defining multidrug-resistant (MDR) isolates were optimized using results from a further analysis of 253 long bone osteomyelitis cases. RESULTS: The B-variable had a classification accuracy of 77.0%, which improved to 95.7% when using a 3D clinical imaging package (p < 0.01). The A-variable demonstrated difficulty in the accuracy of classification for increasingly resistant isolates (A1 (non-resistant), 94.4%; A2 (MDR), 46.7%; A3 (extensively or pan-drug-resistant), 10.0%). Further analysis demonstrated that isolates with four or more resistant test results or less than 80% sensitive susceptibility test results had a 98.1% (95% confidence interval (CI) 96.6 to 99.6) and 98.8% (95% CI 98.1 to 100.0) correlation with MDR status, respectively. The coverage of the soft tissues (C-variable) and the host status (H-variable) both had a substantial agreement between users and a classification accuracy of 92.5% and 91.2%, respectively. CONCLUSIONS: The BACH classification system can be applied accurately by users with a variety of clinical backgrounds. Accuracy of B-classification was improved using 3D imaging. The use of the A-variable has been optimized based on susceptibility testing results.Cite this article: A. J. Hotchen, M. Dudareva, J. Y. Ferguson, P. Sendi, M. A. McNally. The BACH classification of long bone osteomyelitis. Bone Joint Res 2019;8:459-468. DOI: 10.1302/2046-3758.810.BJR-2019-0050.R1.

Management of Post-Traumatic Osteomyelitis in the Lower Limb: Current State of the Art.

Osteomyelitis (OM) of the lower limb represents a large unmet global healthcare burden. It often arises from a contiguous focus of infection and is a recognized complication of open fractures or their surgical treatment, arthroplasty, and diabetic foot ulcers. Historically, this debilitating condition is associated with high rates of recurrence and secondary amputation. However, excellent long-term outcomes are now achieved by adopting a multidisciplinary approach with meticulous surgical debridement, skeletal and soft tissue reconstruction, and tailored antimicrobial treatment. This review focuses on the modern evidence-based management of post-traumatic OM in the lower limb from a reconstructive plastic surgery perspective, highlighting the latest developments and areas of controversy.