Cutibacterium acnes has been the focus of much recent shoulder literature, as it has been found to be both a common cause of periprosthetic joint infection as well as a common contaminant in shoulder surgery. Standard skin preparations have been found to be ineffective at eradicating C. acnes colonization on the skin and deep dermis of patients undergoing surgery. Recent literature has shown that skin preparation with 3% hydrogen peroxide solution is effective for decreasing the rate of cultures positive for C. acnes in both dermal and deep cultures; however, a positive rate of 10%-17% has still been reported despite this skin preparations. The current theory is that standard skin preparation does not remove C. acnes from the deep dermis which subsequently contaminates the deep tissue. We hypothesize that application of 3% hydrogen peroxide to the deep dermal layer immediately following the skin incision will even further decrease the rate of C. acnes contamination during surgery.

Over 50,000 people in the United States have shoulder replacement surgery each year. Of these, it is reported that 0.4%-2.9% of anatomic total shoulder arthroplasties (aTSA) and 1-10% of reverse shoulder arthroplasties (rTSA) are complicated by periprosthetic joint infection (PJI).

Cutibacterium Acnes (C. acnes), an indolent organism found on the skin and in the sebaceous glands around the shoulder and back, makes the diagnosis of shoulder PJI particularly challenging. Multiple studies have shown that C. acnes can be isolated from deep cultures in up to 40% of patients without prior surgery undergoing primary total shoulder arthroplasty, although whether this indicates actual colonization of the joint or contamination is an area of debate.

A recent development in shoulder surgery is the use of hydrogen peroxide to decrease the C. acnes load in the deep dermis sebaceous glands, with the hope that this will prevent contamination of the joint during shoulder joint replacement surgery. Application of a widely commercially-available 3% topical Hydrogen peroxide in water solution in vitro has been found to completely eradicate C. acnes growth within 5 minutes and has been shown in clinical trials when used as part of the skin preparation to decrease the rate of positive cultures for C. acnes from 35% to 10% for deep cultures and from 34% to 17% for superficial dermal cultures. While these results show marked improvement compared to standard skin preparations, the 17% with positive dermal cultures is still concerning given the significant morbidity associated with a PJI.

Our hypothesis is that an additional application of hydrogen peroxide to the dermis itself, immediately following the skin incision, will be even more effective at eradicating this potential source of contamination deep in the joint.

Inclusion Criteria:

• Male patients, age 40-90
• Undergoing primary anatomic or reverse total shoulder arthroplasty for glenohumeral osteoarthritis or rotator cuff arthropathy

Exclusion Criteria:

• Female patients
• Patients under 40 years or over 90 years of age
• Diagnosis other than glenohumeral osteoarthritis or rotator cuff arthropathy
• Prior arthroscopic or open shoulder surgery on the ipsilateral shoulder
• Prior diagnosis of septic shoulder of the ipsilateral shoulder
• Corticosteroid injection within 3 months of the procedure
• Recently on antibiotics (within 2 weeks) prior to surgery

Male patients

6 weeks

Subjects will then be randomized 1:1 into Experimental or Control cohorts.