How Effective is Vancomycin for Preventing Infections after TSA?

Tom Wright, MD

Read complete study: The cost effectiveness of vancomycin for preventing infections after shoulder arthroplasty: a break-even analysis

Surgical site infection is one of the most common and expensive post-operative complications to manage in shoulder arthroplasty. The combination of increased methicillin resistance and decreased efficacy of IV cephlasporins, and Propionibacterium acnes  infections , has led shoulder specialists to look for other methods to prophylax against infections in shoulder arthroplasty. Primary shoulder arthroplasty infection rates have been reported from 0-4%, and with revision arthroplasty, the rates are higher, occurring from 4-15% of the time. Although these rates are low, an infection in a shoulder arthroplasty has devastating effects on the patient and is extremely expensive. Surgical site infection accounts for 22% of all health care related infection costs estimated from $1-10 billion annually.

The authors in this article have been using vancomycin powder in the wound bed before closing the surgical site. The authors have looked at the reports from spine surgeries that have shown significant reduction in infection rates when comparing non-vancomycin treatment vs. vancomycin treatment. Based on this information, they have been using vancomycin powder in their shoulder operations since 2013. As with all things in our current health care system, any increase in cost must be justified, and this paper aims at looking at the cost effectiveness of treating patients preemptively with vancomycin powder in the local wound site. They looked at the average cost of 16 patients being treated for infection and quantified the stages of treatment and cost at each stage. The general standard of care for an infected shoulder arthroplasty for patients is as follows:

  1. Arthroscopic biopsy/aspiration
  2. Resection arthroplasty/ Antibiotic impregnated spacer
  3. PICC/Home care for 6 weeks
  4. Repeat biopsy
  5. Revision reverse shoulder arthroplasty

This treatment protocol for these 16 patients averaged $46,744.54 per patient. At the same facility a 1000mg bottle of vancomycin cost $17.15. Based on these data points, the analysis showed that the treatment with vancomycin powder needed to only reduce infection by .04% to be deemed cost effective (break-even).

My practice in a University setting tends to have a large referral base for revisions, which carries a higher infection rate. Because of this high-risk patient population (revision shoulder arthroplasty) and the significant resistance to cephlosporins, it caused me to review the spine literature.

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Does Post-op Protocol Affect Function and Pain After TSA?

Felix  Savoie, MD

Read complete study: Immediate versus delayed passive range of motion following total shoulder arthroplasty 

A recent article from Denard and Ladermann looked at the difference in ROM, VAS pain scores and ASES scores between differing post-op protocols of immediate motion and delayed motion.

The immediate motion group wore a sling for four weeks following surgeries; passive forward flexion and passive external rotation of the shoulder joint was started on day one post-op. Active hand, wrist and elbow exercise and active scapular retraction were allowed immediately as well. At four weeks, the sling was discontinued and passive external rotation was allowed as tolerated. Strengthening was initiated routinely at eight weeks post-op.

In the delayed motion group, a sling was worn for four weeks following surgery. During these four weeks, patients only performed active hand, wrist and elbow exercises, as well as scapular retraction exercises. At four weeks, the sling was discontinued and passive forward elevation and external rotation was allowed as tolerated. At eight weeks pot-op, active assisted progression to active ROM was allowed and strengthening was routinely started. Activities were allowed as tolerated at 16 weeks post-op with a lifetime recommendation of no overhead lifting of 25lbs or more.

The findings of the article showed that at one year post-op there was no difference between the two groups in ROM, ASES and VAS pain. An interesting finding in this paper was that the immediate motion group had a higher failure rate of the tuberosity osteotomy used to repair the subscapularis. The authors point out that immediate motion group saw initial improvements in ROM, but after three months both groups had relatively the same ROM. The benefit of early motion may not outweigh the risk of the subscap failure, which in my opinion, is a major risk of total shoulder arthroplasty.

I also employ a subscapularis sparing technique on high-demand younger patients where early motion is achievable and risk to the subscapularis is minimal.

My current post-op protocol is to protect the subscapularis for approximately six weeks if I have to detach it. I usually use a thin LT osteotomy,  but I also employ a subscapularis sparing technique on high-demand younger patients where early motion is achievable and risk to the subscapularis is minimal. The technique uses a modified technique through the delto-pectoral approach approximately 50 percent of the inferior subscapularis is taken down while keeping the top 50 percent attached.

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