Propionibacterium Acnes Infection

This is a randomized trial of benzoyl peroxide soap versus Hibiclens soap for surgical preparation. The objective is to determine whether benzoyl peroxide soap, commonly available in drug stores for over-the-counter acne treatment, is as or more effective than the standard surgical preoperative soap, Hibiclens soap (chlorhexidine gluconate), in reducing loads of Propionibacteria (Propi) on or under the skin of patients prior to shoulder arthroplasty (joint replacement).

This is a prospective, randomized controlled trial to evaluate the ability of hydrogen peroxide preparation in addition to chlorhexidine to decrease the colonization of Propionibacterium acnes(a bacteria commonly found in the dermis of the skin surrounding the shoulder in order to decrease postoperative joint infection.

Subclinical infection of the intervertebral disc after lumbar disc herniation surgery has been correlated to chronic low back pain and vertebral endplate changes. The most commonly reported agent is Propionibacterium acnes. However, the real incidence is unclear, as it has been reported in some series ranging from 3.7% to 46%. Recently, a systematic review concluded that there is a relationship between P. acnes and endplate changes, but, there are so far no studies to verify whether the reported presence of that pathogen in the intervertebral discs is due to local infection or whether intraoperative contamination occurred during the collection of samples.
Thus, the main objective of this study is to estimate the incidence of subclinical infection in patients surgically treated for lumbar disc herniation.
To this end, a prospective cohort study will be conducted with a minimum of 95 patients between 18 and 65 years of age who have been submitted to surgery after failure of conservative treatment. The extruded disc will be removed and cultured for bacterial identification. As controls, the ligamentum flavum and the multifidus muscle, taken respectively before and after removal of the herniated fragment will also be cultured. Patients will be followed-up for a year and MRI will be done at the end of this period.