Cutibacterium periprosthetic infection of the shoulder in a young man - an instructive honeymoon

An active 34 year old man presented with pain and limited function of his right shoulder and the x-rays shown below.
 

Because he wished to avoid the risks and limitations of a plastic glenoid component, elected to proceed with a ream and run procedure. 

After which he returned to full comfortable function for 13 years.

However at 14 years after his ream and run, he presented with a 9 month history of unexplained pain and stiffness of his shoulder.  His x-rays at that time were unremarkable, showing no evidence of glenoid wear, erosion, loosening or adaptive changes.

His shoulder was stiff, but not tender or swollen. His white cell count and differential, sedimentation rate, and C reactive protein were all normal. A joint aspiration was not attempted.

He elected a revision surgery with soft issue releases and head exchange. The stem was well fixed; the exposed part of the stem was scrubbed with a wire brush, but not exchanged. There was minimal joint fluid. A frozen section showed only giant cell reaction and fibrous tissue without neutrophils. Deep tissue specimens and the head explant were sent for aerobic and anaerobic culture. The wound was throughly debrided and irrigated with Betadine and saline; topical vancomycin was applied.  After his revision, he was placed on oral Doxycycline.

 

Three weeks after surgery, his culture results were finalized, documenting a periprosthetic infection:

Joint fluid: No growth

Head explant: 1+ Cutibacterium

Collar membrane: 1+ Cutibacterium

Humeral bone: 1+ Cutibacterium

Biceps tendon: 1+ Cutibacterium

His oral Doxycycline was extended for a total of 12 weeks.

He subsequently made an excellent recovery of comfort and function. 

Comment: This case is of interest for serveral reasons: (1) the appearance of a Cutibacterium PJI after a honeymoon of over a decade with excellent shoulder function leaves open the question of the source of these bacteria (were they introduced at the original surgery or did they become introduced later?). (2) the joint fluid did not grow bacteria, while all of the deep tissue and explant cultures did (suggesting that the bacteria were not planktonic, but were in biofilms on tissue and metal - a preoperative fluid aspiration would have been falsely negative). (3) the blood work and the frozen section did not suggest infection (suggesting the value of taking cultures at the time of all revisions, performing a thorough debridement and irrigation, applying topical antibiotics and keeping the patient on oral antibiotics until the results are known). (4) the well fixed stem was left in place to avoid the risk of fracture (only time will tell if the retained stem will give risk to recurrent infection).

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Here are some videos that are of shoulder interest
Shoulder arthritis - what you need to know (see this link).
How to x-ray the shoulder (see this link).
The ream and run procedure (see this link).
The total shoulder arthroplasty (see this link).
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).
The smooth and move procedure for irreparable rotator cuff tears (see this link)
Shoulder rehabilitation exercises (see this link).

Why use topical Vancomycin powder as infection prophylaxis in shoulder arthroplasty?

Periprosthetic infection is a serious complication of shoulder arthroplasty. The most common causative organism is Cutibacterium residing in the pilosebaceous units of the dermis overlying the shoulder. As pointed out in a recent post (see this link), these commensal organisms cannot be eradicated by skin preparation prior to making the incision for shoulder arthroplasty. The result is unavoidable contamination of the wound (see Propionibacterium can be isolated from deep cultures obtained at primary arthroplasty despite intravenous antimicrobial prophylaxis). 

Whether or not this contamination results in a periprosthetic infection depends on (1) the interaction between the host and bacterium and (2) the details of the surgical procedure: the intravenous prophylactic antibiotics used, open wound time, and the composition of the implants. Other measures may help manage the contamination before it establishes a biofilm on the implants: copious irrigation, povidone-iodine lavage and topical in-wound vancomycin. The effectiveness of these measures is difficult investigate rigorously because of the relative infrequency of Cutibacterium infections, the stealthy way in which they typically present, and - in most cases - the need to obtain deep tissue or explant specimens for cultures to determine if an infection is present.

Admitting the need for more robust evidence, let us review some of the information supportive of the use of topical vancomycin in reducing the risk of Cutibacterium periprosthetic infection. 

(1) The cost is low: if 1 to 2 grams are used, the total cost per surgery would range from $10 to $40.

(2) The risk is low:  The risks of vancomycin intravenous infusion reaction are minimized with topical use. The risks of allergy, nephrotoxity and ototoxicity are low with topical administration due to the limited systemic levels.

(3) In vitro data supportive of its effectiveness

    a) 2013 Antimicrobial Susceptibility of Propionibacterium acnes Isolates from Shoulder Surgery: Cutibacterium isolates from shoulder surgery were susceptible to vancomycin.

    b) 2017 In vitro susceptibility of Propionibacterium acnes to simulated intrawound vancomycin concentrations: When administered in a fashion meant to simulate time-dependent in vivo intrawound concentrations, vancomycin exhibited bactericidal activity against P. acnes [Cutibacterium].

     c) 2022 Vancomycin is effective in preventing Cutibacterium acnes growth in a mimetic shoulder arthroplasty: Vancomycin administration effectively prevented C acnes growth in a bioartificial shoulder joint mimetic implant.

(4) Clinical data

    a) 2011 Intrawound application of vancomycin for prophylaxis in instrumented thoracolumbar fusions.   Adjunctive local application of vancomycin powder decreased the postsurgical wound infection rate with statistical significance in posterior instrumented thoracolumbar spine fusions.

    b) 2017 The cost effectiveness of vancomycin for preventing infections after shoulder arthroplasty: a break-even analysis: the prophylactic administration of local vancomycin powder during shoulder arthroplasty is a highly cost-effective practice.

    c) 2017 Intrawound Vancomycin Powder Reduces Early Prosthetic Joint Infections in Revision Hip and Knee Arthroplasty: The use of intrawound vancomycin powder was associated with a significant reduction in the overall incidence of early PJIs following joint arthroplasty, however, only the revision procedures demonstrated a significant reduction in the rate of early PJIs.

    d) 2023 Vancomycin powder embedded in collagen sponge decreases the rate of prosthetic shoulder infection: Intrawound vancomycin powder significantly reduced the rate of periprosthetic shoulder infections without any increase in local and systemic aseptic complications at a minimum follow-up of 12 months. 

    e) 2024 Prophylactic use of vancomycin powder on postoperative infection after total joint arthroplasty: This systematic review of retrospective studies found that local prophylactic use of vancomycin powder in TJA can significantly reduce the incidence of postoperative infection.

Comment: Periprosthetic infection are devastating for the patient. Many variables influence a patient's risk, including sex, age, immune defenses, medications, comborbidities, prior surgery, prior injections, skin microbiome, bacterial virulence, surgical procedure, surgical time, as well as preoperative, intraoperative and postoperative prophylactic measures. Controlling for these variables to single out the clinical effectiveness of topical vancomycin in reducing infection rate would be a statistical nightmare. Laboratory data are encouraging and have the advantage of tightly controlling the variables, but they cannot duplicate the clinical situation.

Let's keep our eyes out for more light to shine on this topic.

Comments welcome at shoulderarthritis@uw.edu

You can support cutting edge shoulder research that is leading to better care for patients with shoulder problems, click on this link

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Here are some videos that are of shoulder interest
Shoulder arthritis - what you need to know (see this link).
How to x-ray the shoulder (see this link).
The ream and run procedure (see this link).
The total shoulder arthroplasty (see this link).
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).
The smooth and move procedure for irreparable rotator cuff tears (see this link).
Shoulder rehabilitation exercises (see this link). 

Removing Cutibacterium from the Skin

It is generally recognized that Cutibacterium originating from the patient's skin is the commonest organism associated with shoulder periprosthetic infections. While these organisms normally populate the skin's epidermal surface, they reside in the pilosebaceous units of the dermis - especially in the areas over the shoulder, back and face and especially in male patients. The surgical incision for shoulder arthroplasty must transect many of these structures, allowing the Cutibacterium to fall into the wound, potentially contaminating the arthroplasty.

Surgeons routinely "prep the skin" with various solutions, however the effectiveness of a skin surface prep has been shown to be suboptimal given the subsurface location this bacterial reservoir. 

Some authors have indicated that the addition of hydrogen peroxide (H2O2) may increase the effectiveness of a chlorhexidine gluconate (CHG) prep (which is the most common solution applied before shoulder arthroplasty).

The authors of Does adding hydrogen peroxide to chlorhexidine gluconate increase the effectiveness of skin preparation in reducing cutaneous Cutibacterium levels? A randomized controlled trial studied eighteen male volunteers; the two shoulders of each volunteer were randomized to receive either (A) the control preparation - 2% CHG in 70% isopropyl alcohol alone (CHG) or (B) 3% H2O2 followed by 2% CHG in 70% isopropyl alcohol (H2O2!CHG). 

Skin swabs were taken from each shoulder prior to skin preparation and again at 60 minutes after preparation. Swabs were cultured for Cutibacterium and observed for 14 days. Cutibacterium skin load was reported using a semiquantitative system based on the number of quadrants growing on the culture plate, thus the range for the Specimen Cutibacterium Value (SpCuV) is 0 to 4. This is an example of a 4, all four quadrants have growth.

Prior to skin preparation, 100% of the CHG-only shoulders and 100% of the H2O2!CHG shoulders had positive skin surface cultures for Cutibacterium. 

The mean SpCuV for the CHG-only shoulders prior to preparation was 2.1 +/- 0.8.
The mean baseline SpCuV for the H2O2!CHG shoulders prior to preparation  was 2.2 +/- 0.7.

The mean SpCuV for the CHG-only shoulders 60 minutes after preparation was 1.3 +/- 0.9.
The mean SpCuV for the H2O2!CHG shoulders 60 minutes after preparation was 1.4 +/- 0.9 

There was a reduction of Cutibacterium load at 60 minutes in 10 (56%) of the CHG-only shoulders.
There was a reduction of Cutibacterium load at 60 minutes in 11 (61%) of the H2O2!CHG shoulders.

The mean reduction in SpCuV at 60 minutes was 0.8 for the CHG-only group
The mean reduction in SpCuV at 60 minutes was 0.8 for the H2O2!CHG group.

After 60 minutes, Cutibacterium had repopulated the skin surface on 14 (78%) of the CHG-only shoulders.
After 60 minutes, Cutibacterium had repopulated the skin surface on 14 (78%) of the H2O2!CHG shoulders.

Comment: These data corroborate other studies indicating that Cutibacterium cannot be removed from the skin by skin preparation of the shoulder. 

While skin surface preparations may be of some value in temporarily reducing the load of these organisms, a combination of host defenses along with intraoperative and postoperative prophylactic measures must be relied on to defend the shoulder against periprosthetic infection.

Comments welcome at shoulderarthritis@uw.edu

You can support cutting edge shoulder research that is leading to better care for patients with shoulder problems, click on this link


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Here are some videos that are of shoulder interest
Shoulder arthritis - what you need to know (see this link).
How to x-ray the shoulder (see this link).
The ream and run procedure (see this link).
The total shoulder arthroplasty (see this link).
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).
The smooth and move procedure for irreparable rotator cuff tears (see this link).
Shoulder rehabilitation exercises (see this link). 

Cutibacterium - why is it so difficult to get them out of bones and joints?

Cutibacterium (propionibacterium) was long dismissed as just a normal inhabitant of the skin, a cause of acne, a slow‐growing facultative anaerobe, a non-virulent organism, and a contaminant when found in intraoperative cultures.

Now, however, clinical scientists point out that Cutibacterium is the organism most commonly associated with periprosthetic infections of the shoulder. And, furthermore, Cutibacterium has the ability to persist in prosthetic wounds, in spite of prophylaxis, surgical treatment and antibiotic management.

This persistence is likely to multifactorial, related in part to the large amounts of this organism on the skin, the host's inability to recognize Cutibacterium as "a foreign invader", and the ability of this organism to form biofilms that protect it from antibiotics and immune response.

Recently, the authors of Cutibacterium acnes invades submicron osteocyte lacuno‐canalicular networks following implant‐associated osteomyelitis uncovered more information bearing on the challenge of eliminating this organism from arthroplasty wounds. They developed an implant-associated osteomyelitis model in which mice were subjected to transtibial implantation of titanium or stainless-steel pins contaminated with Cutibacterium. Using in vitro scanning electron microscopy (EM) they confirmed that Cutibacterium can form biofilms on stainless-steel and titanium implants - two of the common metals used in prosthetic implants. In their model, Cutibacterium persisted for 28 days not only in the tibia but that it also disseminated to internal organs. 

Transmission EM revealed the presence of Cutibacterium within bone canaliculi. These data revealed that the osteocyte lacuno-canalicular networks can serve as a sheltered reservoir in which Cutibacterium can persist long after inoculation. 

This adds yet another possible mechanism explaining why Cutibacterium chronic implant-associated bone infections can be delayed in their presentation and difficult to treat.

One of the striking features of this work is that it demonstrates biofilm formation with bacterial adherence to the pin surface as early as 3 hours after implantation. Progressive biofilm formation was seen with increasing pin incubation time as shown below

The recovery of Cutibacterium from bone, soft tissue, liver, kidneys, heart and spleen at 28 days after implantation demonstrates the systemic spread of the organism and inability of the host to resolve the infection. 

Comment: Cutibacterium can now be recognized as a virulent bacteria because of its high ability to cause disease - in part because it evades the host' immune system and in part because of its defense mechanisms, including biofilm formation and, as suggested in this article reporting on results from a murine model, its ability to colonize bone canaliculi.

The dermal pilosebaceous units of the skin overlying the shoulder - especially those in young men - are loaded with Cutibacterium. Investigations have shown that skin preparations are not effective in eliminating Cutibacterium from the dermis. Thus the incisions used for shoulder arthroplasty routinely allow Cutibacterium to enter the wound and potentially participate in the formation of a biofilm on the surface of the implant. 

Further research is needed to define ways to reduce the bacterial load that is introduced at the time of arthroplasty as well as the risk of subsequent biofilm formation.

Comments welcome at shoulderarthritis@uw.edu

You can support cutting edge shoulder research that is leading to better care for patients with shoulder problems, click on this link

Follow on twitter/X: https://x.com/RickMatsen
Follow on facebook: https://www.facebook.com/shoulder.arthritis
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Here are some videos that are of shoulder interest
Shoulder arthritis - what you need to know (see this link).
How to x-ray the shoulder (see this link).
The ream and run procedure (see this link).
The total shoulder arthroplasty (see this link).
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).
The smooth and move procedure for irreparable rotator cuff tears (see this link).
Shoulder rehabilitation exercises (see this link). 

What is a shoulder infection?

While the diagnosis of obvious shoulder infection is easy: the patient has local and systemic signs of inflammation, abnormal joint fluid and serum lab tests, and positive cultures for indisputable pathogens. 

On the other hand, the diagnosis of a stealth shoulder infection is complicated: the most frequently implicated bacteria (Cutibacterium) is a commensal organism commonly isolated from normal skin, normal deep tissues and healthy shoulder joints. In a stealth infection the usual clinical evidence of infection is absent.

A pragmatic definition of bacterial infection is "bacteria doing harm". That is, the presence of bacteria in and of itself is not sufficient to prove infection. Bacteria in the large intestine; bacteria in sebaceous glands; bacteria recovered from normal joints would not meet the definition whereas E. coli colitis, acne, and joint sepsis would. 

A recent paper,The incidence of subclinical infection in patients undergoing revision shoulder stabilization surgery: a retrospective chart review, exemplifies the challenge. The authors sought to identify the incidence of subclinical infection in 107 patients undergoing revision shoulder stabilization surgery by an experienced shoulder surgeon. Notably the average time from the instability repair to revision was 8 years. The reasons for revision were not provided. Surgical findings (synovitis, purulence, gram stain results) were not given. 

Twenty-nine patients (27.1%) had positive cultures. Patients had multiple specimens sent for culture; the average and range for the number of cultures submitted is not provided. Thirteen patients had only1 positive culture (11 for Cutibacterium). 9 patients had two positive cultures Eight had 3 or more positive cultures (all for Cutibacterium). 

 The paper does not state whether the patients were given antibiotic coverage for the several weeks while the culture results were pending rather than waiting until the results were finalized. The treatment for those patients with positive cultures is not provided.

Twenty-six of these patients (90%) had positive Cutibacterium cultures. The average time to culture positivity was 11 days.

The paper does not state whether any patients developed clinical manifestations of infection.

Comment: It is difficult to know whether these positive cultures obtained on average 8 years after surgery in the absence of other supporting evidence actually represent an infection, i.e. did the bacteria cause harm?

If the surgeon is suspicious of an infection, a reasonable strategy would be to perform a thorough debridement and irrigation at the time of revision, take cultures for Cutibacterium, consider topical antibiotics, and postoperative antibiotics to be continued until the culture results are finalized.     Bases covered.

You can support cutting edge shoulder research that is leading to better care for patients with shoulder problems, click on this link.

Follow on twitter: https://twitter.com/RickMatsen or https://twitter.com/shoulderarth
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Here are some videos that are of shoulder interest
Shoulder arthritis - what you need to know (see this link).
How to x-ray the shoulder (see this link).
The ream and run procedure (see this link).
The total shoulder arthroplasty (see this link).
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).
The smooth and move procedure for irreparable rotator cuff tears (see this link).
Shoulder rehabilitation exercises (see this link).

Shoulder infections - 20 things to know.

Infection can be a major complication for patients having shoulder surgery. 

Posts on this shoulder blog have provided evidence that:

(1) Cutibacterium - commensal bacteria commonly found in the dermis of normal skin - are the most common organism causing periprosthetic infections (PJI) of the shoulder. By contrast infections of total hip and total knee replacements are usually caused by other types of bacteria. 

(2) Cutibacterium are often isolated from specimens obtained at revision for a failed arthroplasty, even in the absence of a preoperative suspicion of PJI.

(3) The risk of Cutibacterium PJI is increased in young, healthy male patients having had prior surgery, patients having high loads of Cutibacterium on their skin surface, in patients taking supplemental testosterone, and those with recent steroid injections of the shoulder.

(4) These organisms are released into the surgical wound from the dermis when the skin incision is made

(5) Cutibacterium cannot be eliminated from the dermis by presurgical skin treatment, preoperative antibiotics, or surgical skin preparation

(6) While Betadine or antibiotic irrigation solutions and in-wound antibiotics may be helpful in reducing the load of bacteria in the surgical field, the evidence that they reduce the rate of infection is not robust.

(7) Cutibacterium tend to form an adherent biofilm, especially on titanium-alloy stems; thus, complete prosthesis exchange after debridement may be necessary to resolve an infection.

(8) Some infections are obvious (redness, swelling, tenderness, elevated serum and synovial fluid inflammatory markers); however, Cutibacterium infections typically have a stealth presentation with the otherwise unexplained onset of pain and stiffness months after the index arthroplasty.

(9) Joint fluid aspiration can be helpful if the fluid is culture positive, but negative cultures do not rule out infection.

(10) At the time of revision surgery at least 5 deep specimens (tissue / explants) need to be submitted for culture in order to optimize the identification of a PJI.

(11) Specimens taken to detect Cutibacterium must be cultured on aerobic and anaerobic media and observed for at least two weeks.

(12) Because the results of these cultures are not finalized for weeks after surgery, patients are placed on antibiotics after revision surgery until the culture results are known.

(13) In rare cases if an infection is diagnosed soon after the primary arthroplasty, consideration can be given to debridement and irrigation with retention of the implants and antibiotic therapy after surgery. This may be an option for patients with cemented implants and patients who may not be sufficiently healthy for a major revision.

(14) In cases with a stealth presentation of pain and stiffness after a "honeymoon" period of routine post-arthroplasty recovery, consideration is often given to a single stage exchange with vigorous debridement and postoperative antibiotics until the culture results are finalized.

(15) In cases of obvious infection (redness, tenderness, swelling, drainage, elevated inflammatory markers, or wound drainage) and in cases of failed single stage revision, a two-stage revision can be considered (stage 1: implant removal, cultures, irrigation, implantation of an antibiotic-containing spacer, post operative antibiotics; when evidence of infection no longer present=>stage 2: repeat debridement, cultures, definitive implant insertion, and postoperative antibiotics).

(16) Two stage revisions are more costly and complication-prone than single stage revisions

(17) With either single stage or the second of a two-stage, it is possible that a re-revision may be necessary - this possibility should be considered in selecting how the implants are fixed in the bone.

(20) With respect to post operative antibiotics: (a) in most cases, oral antibiotics seem to be as cost-effective as IV antibiotics and (b) at least six weeks of antibiotics are recommended if >2 of the deep specimens are culture positive for the same organism. Prolonged antibiotic therapy is considered in cases where recurrent infection is more likely.

Use search box (upper right of this page) to find more posts on these topics

 
Here are a few recent articles that may be of interest.

Prevention

Does preoperative corticosteroid injection increase the risk of periprosthetic joint infection after reverse shoulder arthroplasty? reported a significantly increased risk of PJI in patients who received corticosteroid injections (CJI) within 1 month of reverse total shoulder, but not those who received CSI more than 1 month before RSA. Alcohol abuse, chronic kidney disease, and depression were also identified as factors increasing the risk of PJI.

The authors of Effect of supplemental testosterone use on shoulder arthroplasty infection rates concluded that testosterone use within 6 months of shoulder arthroplasty may be associated with higher rates of prosthesis joint infection. 

Photodynamic therapy for Cutibacterium acnes decolonization of the shoulder dermis found that the use of photodynamic therapy did not significantly reduce dermal colonization of Cutibacterium (as determined by punch biopsy cultures) as compared to standard skin preparation. The overall positive culture rate was 54%. All positive cultures identified Cutibacterium except for one.

Effect of Making Skin Incision with Electrocautery on Positive Cutibacterium acnes Culture Rates in Shoulder Arthroplasty: A Prospective Randomized Clinical Trial discovered that cultures obtained from the incised dermal edge immediately after skin incision were less likely to be positive if electrocautery was used in making the skin incision. However, there was no significant difference in the positive culture rate in samples from gloves and forceps taken immediately prior to humeral component implantation. Thus, use of cautery did not reduce the rate of wound innoculation.

Betadine and topical vancomycin may be of value in reducing the rate of periprosthetic infection.[Vancomycin powder embedded in collagen sponge decreases the rate of prosthetic shoulder infection] [Dilute povidone-iodine irrigation reduces the rate of periprosthetic joint infection following hip and knee arthroplasty: an analysis of 31,331 cases][A systematic review and meta-analysis comparing intrawound vancomycin powder and povidone iodine lavage in the prevention of periprosthetic joint infection of hip and knee arthroplasties][Systematic review and meta-analysis of intrawound vancomycin in total hip and total knee arthroplasty: a continued call for a prospective randomized trial.]

Bariatric surgery performed with the goal of reducing body mass is associated with higher risks of PJI, implant failure, and dislocation, especially if the arthroplasty is performed within two years of the bariatric surgery. [Prior bariatric surgery is associated with an increased rate of complications after primary shoulder arthroplasty independent of body mass index] [Does bariatric surgery prior to primary total knee arthroplasty improve outcomes?][Does Bariatric Surgery Prior to Primary Total Hip Arthroplasty Really Improve Outcomes?]

Diagnosis

The Incidence of Subclinical Infection in Patients Undergoing Revision Shoulder Stabilization Surgery: A Retrospective Chart Review twenty-nine (27%) of 107 patients having revision surgery had positive cultures. Twenty-six patients had positive Cutibacterium cultures; these cultures took an average of 10.65 days to turn positive. The authors suggest that surgeons consider infection as a reason for lack of clinical improvement and possibly needing revision surgery after shoulder stabilization. 

In The role of sonication in the diagnosis of periprosthetic joint infection in total shoulder arthroplasty the standard synovial fluid cultures combined with intraoperative periprosthetic tissue cultures had a sensitivity of 95%, specificity of 95% and total accuracy of 95%. Sonication cultures had a sensitivity of 91%, specificity of 68% and total accuracy of 80%. 

Treatment

Outcomes after Debridement, Antibiotics, and Implant Retention for Prosthetic Joint Infection in Shoulder Arthroplasty found that 29.4% of thee patients were diagnosed as having recurrent infection on chart review.

High infection control rate after systematic one-stage procedure for shoulder arthroplasty chronic infection found that 36/40 patients had no recurrence of infection after the one stage revision. Cutibacterium was the most frequent pathogen isolated, found in 67.5% (27/40) of the patients. The infection was polymicrobial in 40% (16/40) of the cases.

One-stage revision for infected shoulder arthroplasty: prospective, observational study of 37 patients found that 95% did not have evidence of recurrent infection. The most commonly isolated pathogen was Cutibacterium acnes (68%), isolated alone (15 patients, 41%) or as polymicrobial infections (10 patients, 27%). 

Outcomes after resection arthroplasty versus permanent antibiotic spacer for salvage treatment of shoulder periprosthetic joint infections: a systematic review and meta-analysis found that when implant exchange after shoulder PJI is not feasible, permanent antibiotic spacers and resection arthroplasty are both salvage procedures that provide similar rates of infection eradication. Although both can decrease pain levels, the permanent antibiotic spacer may result in better functional outcomes compared with resection arthroplasty.

Comment: It is apparent that the experience in the diagnosis and treatment hip and knee PJI cannot be directly applied to the shoulder because of the difference in causative bacteria. 

The diagnosis of shoulder PJI is complicated by the relative frequency of Cutibacterium as the infecting bacteria. Another confunder is the difficulty in differentiating between osteolysis due to particles from polyethylene failure and osteolysis fron PJI. See Loose glenoid component - is the shoulder infected?

Determing the success rates for different treatments of periprosthetic shoulder infections is difficult to assess. Many of the publications reporting different therapeutic approaches lack appropriate controls and clear measures of treatment effectiveness.

 Often shoulders continue to be painful and stiff after a revision procedure. Because clinical symptoms, signs and lab tests are insensitive to the presence of Cutibacterium, the diagnosis of recurrent infection may be overlooked unless a re-revision with intraoperative cultures is performed. The lack of a re-revision procedure is not proof that an infection has been resolved. Alternatively, re-revision may be indicated for non-infectious issues and does not necessarily indicate failure of the treatment of infection. 

Considering all of the above, an approach to the management of the failed arthroplasty is to consider the possibility of infection unless another cause of failure is evident.

You can support cutting edge shoulder research that is leading to better care for patients with shoulder problems, click on this link.

Follow on twitter: https://twitter.com/shoulderarth
Follow on facebook: click on this link
Follow on facebook: https://www.facebook.com/frederick.matsen
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Here are some videos that are of shoulder interest
Shoulder arthritis - what you need to know (see this link).
How to x-ray the shoulder (see this link).
The ream and run procedure (see this link).
The total shoulder arthroplasty (see this link).
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).
The smooth and move procedure for irreparable rotator cuff tears (see this link).
Shoulder rehabilitation exercises (see this link).

Which patients are at risk for stiffness after a ream and run glenohumeral arthroplasty?

Patients with glenohumeral arthritis considering shoulder arthroplasty may wish to avoid the activity limitations and the risk of complications associated with the polyethylene glenoid component used in traditional total shoulder arthroplasty. Avoiding the prosthetic glenoid component eliminates the risk of revision related to glenoid wear, glenoid loosening, and humeral component loosening associated with polyethylene wear. These patients may elect the ream and run glenohumeral arthroplasty (RnR) (see this link).

Some patients experience stiffness after the RnR which, if severe, can lead to repeat procedures such as a manipulation under anesthesia (MUA) or an open surgical revision. The authors of Risk Factors for Stiffness Requiring Intervention After Ream-and-Run Arthroplasty sought to determine risk factors associated with repeat procedures performed for postoperative stiffness after ream and run arthroplasty.

They identified 340 patients who underwent the ream and run arthroplasty in a longitudinally maintained database with a mean follow-up of 2.1 years. Patients who underwent a repeat procedure and the control group of patients who did not undergo a repeat procedure had similar preoperative mean SST scores (4.8 compared with 5.0) and SANE scores (38.8 compared with 41.0). The mean Simple Shoulder Test (SST) scores for all patients significantly improved from 5.0  preoperatively to 10.2 postoperatively. The mean SANE scores improved from 40.6 preoperatively to 80.3 postoperatively. 

Thirty-five patients (10.3%) elected to undergo an MUA. These procedures were performed at a mean of 8.7 months after the index arthroplasty.

Twenty-six patients (7.6%) underwent subsequent open procedures to treat stiffness. Four patients underwent a conversion to an anatomic total shoulder arthroplasty; the remaining 22 patients had soft tissue releases and downsizing of the humeral head component thickness. These procedures were performed at a mean of 20.6 months (range, 0.9 to 71.7 months) after the index arthroplasty. 

At the time of open revision, 69.2% (18 of 26) had ≥2 cultures positive for Cutibacterium.

Younger age, female sex, and lower American Society of Anesthesiologists (ASA) class were significant risk factors for repeat procedures. Patients who underwent a repeat procedure had greater preoperative posterior decentering (10.7% compared with 8.1%) but similar Walch classification and preoperative retroversion. Patients who required a repeat procedure had less forward elevation (125.7° compared with 143.3°) noted by an individual designated physical therapist at the time of hospital discharge after the index surgical procedure. Preoperative diagnosis, BMI, insurance type, employment, opioid use, smoking status, prior procedures on the same shoulder, head thickness, use of an eccentric head, and rotator interval plication were not significantly different between those who required repeat intervention and those who did not.

Patients who underwent a repeat procedure had lower mean scores at 2 years for the SST (8.2  compared with 10.6) and SANE (68.4 compared with 82.7).  The mean SST scores of patients undergoing MUA (6.2) were significantly lower  than those of patients undergoing open revision (9.7).










Multivariate analysis found younger age, ASA class 1 compared with class 3, and less passive forward elevation at discharge to be independent risk factors for repeat procedures.

Comment: While the overall outcome for these 340 patients were good - the SST improved from 5 out of 12 preopeartively to 10.2 out of 12 at two years after surgery - there are lessons to be learned from this study.

Achieving immediate range of motion and maintaining it throughout the rehabilitation period is essential to the success of the ream and run procedure. Less forward elevation at the time of discharge from the hospital after a ream and run was an independent risk factor for a repeat procedure. This finding demonstrates that the finding of less than 130 degrees of flexion in the immediate postoperative period can identify patients who may benefit from a more aggressive early rehabilitation protocol. 

Younger age and better health were independent risk factors for repeat procedures to address stiffness. Younger patients may have higher expectations and, therefore, a lower threshold for a second procedure to address stiffness. It is also known that stiffness can be caused by a low grade periprosthetic infection from Cutibaterium. Young, healthy patients selecting the ream and run are at greater risk for these infections, which typically present as pain and stiffness in absence of the usual signs of periprosthetic joint infection from other bacteria (elevated serum markers, fever, chills, joint swelling, and a draining sinus). In Factors predictive of Cutibacterium periprosthetic shoulder infections: a retrospective study of 342 prosthetic revisions) the authors found that patients with definite Cutibacterium periprosthetic infections were younger (59 ± 10 vs. 64 ± 12, P < .001) and had lower American Society of Anesthesiologists scores (1.9 ± 0.7 vs. 2.3 ± 0.7, P < .001). In Risk Factors for Stiffness Requiring Intervention After Ream-and-Run Arthroplasty, over two-thirds (69.2%) of the open revisions for stiffness had multiple positive intraoperative cultures for Cutibacterium.  

Preoperative posterior decentering was significantly greater in the group that required repeat intervention. At surgery, posterior decentering may addressed by increasing the thickness or diameter of the prosthetic head, use of an anteriorly eccentric humeral head, and performance of rotator interval plication. These modifications that are carried out to help center the humeral head on the glenoid may contribute to postoperative stiffness,

Patients at risk for postoperartive stiffness may benefit from greater soft-tissue releases, smaller humeral head components, more aggressive rehabilitation, and close monitoring of their range of motion after the surgical procedure. Furthermore, surgeons should be alert to the possibility of Cutibacterium periprosthetic infection in shoulders developing stiffness after the ream and run procedure.

You can support cutting edge shoulder research that is leading to better care for patients with shoulder problems, click on this link.

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Here are some videos that are of shoulder interest
Shoulder arthritis - what you need to know (see this link).
How to x-ray the shoulder (see this link).
The ream and run procedure (see this link).
The total shoulder arthroplasty (see this link).
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).
The smooth and move procedure for irreparable rotator cuff tears (see this link).
Shoulder rehabilitation exercises (see this link).

Postoperative infections of the shoulder - demographics and prevention

Shoulder infections are important causes of failed shoulder surgery. Here is a case of a total shoulder periprosthetic infection by Cutibacterium

A number of recent publications are of interest.

I. The authors of The POSI study: gender differences in 94 cases of postoperative shoulder surgery infection: results of a 7-year retrospective multicenter study reported the characteristics of patients experiencing postoperative shoulder infections. A confirmed shoulder infection was defined as 2 positive cultures or more of the same microorganism, or clear clinical infection with 1 positive culture.

The mean patient age at index surgery was 59 years (range: 22-91) with a majority being men (74%). Arthroplasty was the most common index surgery, followed by fracture fixation, arthroscopic surgery, and other open procedures.

The median time between the index surgery and the first positive sample was 5 months (mean 23 months, minimum 6 days to maximum 27 years). The median time between index surgery and diagnosis for cases with Cutibacterium infections was 8.6 months in contrast to 3.9 months for other organisms.

Cutibacterium species were identified in 64 patients (68%), 59 of which were Cutibacterium acnes (63%). In 86% of cases, Cutibacterium was identified at the first revision. The other 2 most common germs were Staphylococcus epidermidis and Staphylococcus aureus, (29% and 17%, respectively). Polymicrobial infection was present in 30% of patients.

Cutibacterium was twice as frequent in men.
S. epidermidis was twice as frequent in women.
S. epidermidis was 3 times more prevalent in chronic than in acute cases.

Comment: Of note: (1) the long intervals between the index procedure and diagnosis, especially for Cutibacterium infections, (2) the sex difference in frequency of Cutibacterium and S. epidermidis, and (3) 5 of the 64 Cutibacterium infections were by species other than C. acnes.

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II. What is the best IV prophylaxis against shoulder infections? As detailed in this link, cephalosporin antibiotics are most effective in preventing shoulder infections from the two most common causative organisms: Cutibacterium and coagulase negative Staphylococcus. This link also addresses the situation in which the patient reports a penicillin allergy. 

Patients with penicillin "intolerance" history

and patients with low risk penicillin allergy history

can be given cephalosporins with low risk of reactions. Whereas patients with high risk history of penicillin allergy

shoulder receive an alternative antibiotic. Clindamycin is not a good second choice because of the relatively high prevalence of Cutibacterium resistance to this organism. 

The authors of When intravenous vancomycin prophylaxis is needed in shoulder arthroplasty, incomplete administration is associated with increased infectious complications point out that vancomycin is often used as antimicrobial prophylaxis for shoulder arthroplasty (SA) either when cephalosporins are contraindicated or colonization with resistant bacteria is anticipated. Vancomycin is recognized as being inferior to cephalosporins in preventing Cutibacerium infections, possibly due to a higher minimum inhibitory concentration required to eradicate infection; thus, weight-based dosing is important. Vancomycin is different than most other antibiotics used in prophylaxis: it necessitates longer infusion times to mitigate potential side effects, such as Red Man Syndrome or Vancomycin flushing syndrome. When infusion is started too close to the time of the incision, administration may not be complete during surgery. 

These authors evaluated whether incomplete administration of intravenous vancomycin prior to SA affects the rate of infectious complications in primary shoulder arthroplasties (hemiarthroplasty, anatomic total SA, or reverse SA) with minimum two-year followup.

A total of 461 primary SAs were included. Vancomycin infusion was considered incomplete if the administration was not finished by 30 minutes preoperatively. (163 cases), and complete if administration was finished more than 30 minutes preoperative. (298 cases). 

The incomplete group demonstrated significantly higher rates of any infectious complication (8% vs. 2.3%); periprosthetic infection (5.5% vs. 1%), and reoperation inclusive of revision due to infectious complications (4.9% vs. 1%). 

Survivorship free of PJI was worse in SA with incomplete compared to those with complete vancomycin administration. Survival rates for incomplete and complete administration were 

97.6% and 99.3% at 1 mo, 

95.7% and 99.0% at 2 yr, 

95.1% and 99.0% at 5 yr, and 

93.9% and 99.0% at 20 yr, respectively. 

Multivariable analyses confirmed that incomplete vancomycin administration was an independent risk factor for PJI compared with complete administration (hazard ratio, 4.22), even when other independent predictors of PJI (age, male sex, prior surgery, methicillin-resistant Staphylococcus aureus colonization, and follow-up) were considered.

Comment: It is of interest that in this series from a major academic medical center, over one-third of the cases had incomplete administration of vancomycin and that those cases with incomplete administration had over 4 times the rate of infectious complications than those with complete administration. This observation suggests that it is important to obtain high blood concentrations prior to the surgical incision in order to reduce the inoculation of the wound by organisms inhabiting the dermis, such as Cutibacterium, which are not eliminated by the standard surgical skin surface preparations. The desired blood level cannot be achieved if vancomycin administration is started in the operating room because of the need for slow infusion to minimize side effects - the infusion needs to be started in the pre-operative holding area.

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III. TopIcal vancomycin

As described above, achieving high tissue levels of vancomycin with IV administration can be difficult because of the limitations on the rate of administration, because of concern about vancomycin toxicity if the weight-based dosage is exceeded, and because of the difficulties in adhering to the ideal administration timing. These concerns might be effectively addressed by the topical, rather than systemic administration of vancomycin. The authors of Vancomycin powder embedded in collagen sponge decreases the rate of prosthetic shoulder infection sought to evaluate whether Vancomycin powder embedded in a collagen sponge could decrease the rate of prosthetic shoulder infection.

They conducted a retrospective analysis of 827 patients undergoing Total Shoulder Arthroplasty (TSA) with 405 patients having no topical vancomycin and a group of 422 having the intraoperative application of intrawound vancomycin powder. Of note these two groups were not assigned randomly and the patients in each group were not systematically matched. Instead, the authors changed their protocol over the time of the study to include topical vancomycin. 

After 1 year of observation, no infections were observed in the group treated with intrawound vancomycin; 13 cases of infection (3.2%) were observed in the group without vancomycin application. No wound complications requiring revision were observed as a result of intrawound vancomycin. 

IV. Nipping it in the bud

Cutibacterium has the ability to form biofilms, especially on the titanium alloy implants from which many shoulder arthroplasty components are mode. These biofilms protect the sessile organisms from host defenses and antibiotics. Thus the best chance to reduce the size of the Cutibacterium inoculum at the time of primary shoulder arthroplasty is to use agents that act against the organism while it is in its planktonic stage, i.e. before it becomes sessile in a biofilm on the implants. Vancomycin's minimum inhibitory concentration against planktonic Cutibacterium is 0.38 μg/mL while the vancomycin concentration required to eradicate an established biofilm is estimated to be ≥128 μg/mL.  A recent study showed that the concentrations of vancomycin that could be achieved in vivo were effective against planktonic Cutibacterium: In vitro susceptibility of Propionibacterium acnes [Cutibacterium] to simulated intrawound vancomycin concentrations. The authors concluded that when administered in a fashion meant to simulate time-dependent in vivo intrawound concentrations, vancomycin exhibited bactericidal activity against P. acnes.

The authors of another study, Vancomycin is Effective in Preventing C. acnes Growth in a Shoulder Arthroplasty Mimetic found that vancomycin administration effectively prevented Cutibaterium growth in a bioartificial shoulder joint mimetic implant. 

The size of reduction in the rate of periprosthetic joint infections necessary to justify the cost of topical vancomycin was assessed in: The cost effectiveness of vancomycin for preventing infections after shoulder arthroplasty: a break-even analysis These authors concluded that prophylactic administration of local vancomycin powder during shoulder arthroplasty could be highly cost-effective. They estimated that the overall cost to treat an infection is $46,745. Vancomycin costs vary from $2.50 to $44 per gram of vancomycin. At $2.50 per gram, vancomycin only needs to obtain an efficacy of 0.005% in reducing the rate of PJI to be cost-effective, whereas at $44 per gram, the efficacy needs to be 0.09% to be cost- effective.

What we know: 

1. Cutibacterium is the commonest organism to cause shoulder periprosthetic infections; the risk of these infections is increased in young male patients.

2. Cutibacterium live in the dermal pilosebaceous units of the skin overlying the shoulder where they cannot be eradicated by surgical skin surface preparations or by preoperative intravenous antibiotics

3. These dermal pilosebaceous units are incised at shoulder arthroplasty surgery, allowing planctonic Cutibaterium to contaminate the surgical field.

4. If not controlled by host defenses and prophylactic methods, these contaminating organisms can cause shoulder periprosthetic infections that are disabling for the patient and difficult to resolve once a biofilm is formed.

5. The use of topical in-wound Vancomycin appears to be safe and relatively inexpensive.

6. The clinical value of topical in-wound Vancomycin in reducing or eliminating Cutibacterium from the surgical field has yet to be rigorously demonstrated, but deserves careful study.

You can support cutting edge shoulder research that is leading to better care for patients with shoulder problems, click on this link.

Follow on twitter: https://twitter.com/shoulderarth
Follow on facebook: click on this link
Follow on facebook: https://www.facebook.com/frederick.matsen
Follow on LinkedIn: https://www.linkedin.com/in/rick-matsen-88b1a8133/

Here are some videos that are of shoulder interest
Shoulder arthritis - what you need to know (see this link).
How to x-ray the shoulder (see this link).
The ream and run procedure (see this link).
The total shoulder arthroplasty (see this link).
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).
The smooth and move procedure for irreparable rotator cuff tears (see this link).
Shoulder rehabilitation exercises (see this link).