Immunological evaluation of patients with orthopedic infections: taking the Cierny-Mader classification to the next level.

Introduction: Cierny-Mader osteomyelitis classification is used to label A, B, or C hosts based on comorbidities. This study's purpose was to define the "true" host status of patients with orthopedic infection using serologic markers to quantify the competence of their immune system while actively infected. Methods: Retrospective chart review identified patients at a single-surgeon practice who were diagnosed with orthopedic infection between September 2013 and March 2020 and had immunological laboratory results. All patients were A or B hosts who underwent surgery to eradicate infection. Medical history, physical examination, and Cierny-Mader classification were recorded. Laboratory results included complement total, C3, C4, immunoglobulin G (IgG), immunoglobulin M (IgM), immunoglobulin A (IgA), immunoglobulin E (IgE), rheumatoid factor, and antineutrophil cytoplasmic antibodies (ANCA) panel. Clinically significant results were defined as flagged abnormal. Normal complement levels and normal IgG levels were considered abnormal when infection was present. Results: Of 105 patients, 99 (94 %) had documented lab abnormalities. Clinically significant abnormalities were found in 33 of 34 (97 %) type-A hosts and 66 of 71 (93 %) type-B hosts. Eleven of 105 (10.5 %) patients were formally diagnosed with primary immunodeficiency by a hematologist. IgG deficiency, of either low or normal value, in the face of infection comprised 91 % (30 of 34) type-A hosts and 86 % (56 of 71) type-B hosts. Six (5.7 %) patients received IgG replacement therapy. Twenty-eight patients had abnormal total complement levels (low or normal): 7.4 % (2 of 34) A hosts and 40 % (26 of 71) B hosts ( p = 0.002 ). B hosts had statistically significantly lower complement levels and significantly more no-growth cultures ( p < 0.03 ). Thirteen of 14 patients with recurrent infections had low or normal IgG levels. IgM was significantly lower between reinfected patients and those without reinfection ( p = 0.0005 ). Conclusions: Adding immunologic evaluation to the Cierny-Mader classification more accurately determines patients' true host status and better quantifies risk and outcome with respect to orthopedic infection. Immunologically deficient A hosts should be quantified as B hosts. IgG deficiencies may be addressed when deemed appropriate by the consulting hematologist/immunologist. Patients with recurrent infections had significantly lower IgM levels than their nonrecurrent infection counterparts.

Experience with negative-pressure wound therapy with instillation in complex infected orthopaedic wounds.

Chronic exudative wounds are frequently seen in hospitalised patients, consuming hospital resources and leading to increased morbidity. Negative-pressure therapy (NPWT) with topical instillation "NPWTi" may be used to improve the wound healing process, with the unique features (removal of wound exudate, edema reduction, promotion of tissue perfusion and granulation tissue formation, as well as drawing the edges of the wound to facilitate, in addition to the cyclic cleansing mechanism). This report is a descriptive study of our experience with NPWTi on complex infected orthopaedic wounds as a potential method to decrease the need for multiple surgical debridements required for the closure of such wounds. A prospective observational study was conducted. Twenty patients with complex infected orthopaedic wounds were enrolled in our study. These patients were consulted by the Bone and Joint Infection Service and enrolled to receive NPWTi intraoperatively and to be used during their inpatient stay. Twenty patients with 20 complex infected lower limb wounds were included in our study. Of all the 20 wounds, the etiology was post-surgical in 80% (n = 16) and post-traumatic in 20% (n = 4). None of the patients received previous treatment with conventional NPWT before participation in the study. There were 11 males (55%) and 9 females (45%) with an average age of 57 years (22-83). All wounds were located in the lower limbs, with 25% leg (n = 5), 20% thigh (n = 4), 20% knee (n = 4), 20% foot (n = 4), 10% heel (n = 2), and 5% ankle (n = 1). The average length of treatment with NPWTi was 5.2 days (2-10). Successful wound closure within 6 weeks was achieved in 65% of the cases (n = 13). Of the closed wounds (n = 13), 54% (n = 7) were closed primarily and 46% (n = 6) were closed by secondary procedures (skin graft or skin flap). NPWTi is still considered a novel technique that can be used in the management of complex wounds, and the goal of this prospective study is to report our experience with NPWTi in the management of complex infected orthopaedic lower limb wounds. Randomised control studies with optimally matched wounds comparing NPWTi to the conventional methods of treatment are warranted.