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.

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.

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.

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.

The effect of local antibiotic prophylaxis when treating open limb fractures: A systematic review and meta-analysis

Objectives

As well as debridement and irrigation, soft-tissue coverage, and osseous stabilization, systemic antibiotic prophylaxis is considered the benchmark in the management of open fractures and considerably reduces the risk of subsequent fracture-related infections (FRI). The direct application of antibiotics in the surgical field (local antibiotics) has been used for decades as additional prophylaxis in open fractures, although definitive evidence confirming a beneficial effect is scarce. The purpose of the present study was to review the clinical evidence regarding the effect of prophylactic application of local antibiotics in open limb fractures.

Methods

A comprehensive literature search was performed in PubMed, Web of Science, and Embase. Cohort studies investigating the effect of additional local antibiotic prophylaxis compared with systemic prophylaxis alone in the management of open fractures were included and the data were pooled in a meta-analysis.

Results

In total, eight studies which included 2738 patients were eligible for quantitative synthesis. The effect of antibiotic-loaded poly(methyl methacrylate) beads was investigated by six of these studies, and two studies evaluated the effect of local antibiotics applied without a carrier. Meta-analysis showed a significantly lower infection rate when local antibiotics were applied (4.6%; 91/1986) than in the control group receiving standard systemic prophylaxis alone (16.5%; 124/752) (p < 0.001) (odds ratio 0.30; 95% confidence interval 0.22 to 0.40).

Conclusion

This meta-analysis suggests a risk reduction in FRI of 11.9% if additional local antibiotics are given prophylactically for open limb fractures. However, due to limited quality, heterogeneity, and considerable risk of bias, the pooling of data from primary studies has to be interpreted with caution.

Cite this article: M. Morgenstern, A. Vallejo, M. A. McNally, T. F. Moriarty, J. Y. Ferguson, S. Nijs, WJ. Metsemakers. Bone Joint Res 2018;7:447–456. The effect of local antibiotic prophylaxis when treating open limb fractures: A systematic review and meta-analysis. DOI: 10.1302/2046-3758.77.BJR-2018-0043.R1

Single-stage treatment of chronic osteomyelitis with a new absorbable, gentamicin-loaded, calcium sulphate/hydroxyapatite biocomposite: a prospective series of 100 cases

AIMS

Chronic osteomyelitis may recur if dead space management, after excision of infected bone, is inadequate. This study describes the results of a strategy for the management of deep bone infection and evaluates a new antibiotic-loaded biocomposite in the eradication of infection from bone defects.

PATIENTS AND METHODS

We report a prospective study of 100 patients with chronic osteomyelitis, in 105 bones. Osteomyelitis followed injury or surgery in 81 patients. Nine had concomitant septic arthritis. 80 patients had comorbidities (Cierny-Mader (C-M) Class B hosts). Ten had infected nonunions. All patients were treated by a multidisciplinary team with a single-stage protocol including debridement, multiple sampling, culture-specific systemic antibiotics, stabilisation, dead space filling with the biocomposite and primary skin closure.

RESULTS

Patients were followed up for a mean of 19.5 months (12 to 34). Infection was eradicated in 96 patients with a single procedure and all four recurrences were successfully managed with repeat surgery. Adverse events were uncommon, with three fractures, six wound leaks and three unrelated deaths. Outcome was not dependant on C-M host class, microbial culture, wound leakage or presence of nonunion.

CONCLUSION

This single-stage protocol, facilitated by the absorbable local antibiotic, is effective in the treatment of chronic osteomyelitis. It offers a more patient-friendly treatment compared with other published treatment options. Cite this article: Bone Joint J 2016;98-B:1289-96.

The use of a biodegradable antibiotic-loaded calcium sulphate carrier containing tobramycin for the treatment of chronic osteomyelitis: a series of 195 cases

We report our experience using a biodegradable calcium sulphate antibiotic carrier containing tobramycin in the surgical management of patients with chronic osteomyelitis. The patients were reviewed to determine the rate of recurrent infection, the filling of bony defects, and any problems with wound healing. A total of 193 patients (195 cases) with a mean age of 46.1 years (16.1 to 82.0) underwent surgery. According to the Cierny-Mader classification of osteomyelitis there were 12 type I, 1 type II, 144 type III and 38 type IV cases. The mean follow-up was 3.7 years (1.3 to 7.1) with recurrent infection occurring in 18 cases (9.2%) at a mean of 10.3 months post-operatively (1 to 25.0). After further treatment the infection resolved in 191 cases (97.9%). Prolonged wound ooze (longer than two weeks post-operatively) occurred in 30 cases (15.4%) in which there were no recurrent infection. Radiographic assessment at final follow-up showed no filling of the defect with bone in 67 (36.6%), partial filling in 108 (59.0%) and complete filling in eight (4.4%). A fracture occurred in nine (4.6%) of the treated osteomyelitic segments at a mean of 1.9 years (0.4 to 4.9) after operation. We conclude that Osteoset T is helpful in the management of patients with chronic osteomyelitis, but the filling of the defect in bone is variable. Prolonged wound ooze is usually self-limiting and not associated with recurrent infection.