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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What Is the Best Option for Addressing Difficult Glenoids with Implants?

Curtis Noel, MD

Read complete study: Total shoulder arthroplasty for glenohumeral arthritis associated with posterior glenoid bone loss: results of an all-polyethylene, posteriorly augmented glenoid component

The authors reported on 19 patients with 20 total shoulders with minimum two-year follow-up using an augmented glenoid component. They hypothesized the need for augmented glenoids as a way to save bone and prevent medializing the joint line. The average follow-up was 36 months, and the average pre-op retroversion to be corrected was 23.5⁰. The study showed significant improvements in forward elevation and external rotation, while also showing improvements in the SF36 physical form. The implant used in this study was an all-polyethylene, step-cut glenoid with an “anchor peg” for bone growth, in which 12 of the 19 patients showed osseus integration. The conclusion of the authors was that the short-term results are promising for these augmented glenoids, but further research needs to be completed.

Literature Review:

I agree with these authors, and others, on the need to address retroversion in total shoulder arthroplasty. Treating the retroverted glenoid is challenging. For these B2 and B3 glenoids, surgeons have limited options. We know that implanting the glenoid in retroversion is not a good option as it increases the edge loading and leads to early loosening and failure. Reaming down the high side and placing a ‘standard’ glenoid can medialize the joint line and places the implant on subcortical bone, which is also not ideal. Using an anatomic total shoulder with an augmented glenoid implant is an attractive option, as it allows the placement of the implant on more solid bone and maintains the joint line. A final option is placing a reverse total shoulder, which may be the best option for some patients.

I currently prefer a wedge augmented glenoid component, instead of a step-cut implant. In my hands, the wedge glenoid is easier to implant and is more bone preserving.

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What is the Difference in Post-Op Activity Level Between Older and Younger rTSA Patients?

Ryan Simovitch, MD

Read complete study: Younger patients report similar activity levels to older patients after reverse total shoulder arthroplasty

The authors conducted a study to measure a subjective questionnaire that reported type of activities, range of motion, pain and strength. The authors looked at patients younger and older than 65 to determine if there was a difference in activity levels and what the functional differences were in these patient populations. They broke activity level down into low, medium and high demand.

Literature Review:

The authors bring up a good point for surgeons to think about. Older patients are not necessarily inactive patients. The patient population at my practice in South Florida is older demographically, but those patients still enjoy golfing, swimming, lifting weights, cycling, hunting and other similar  activities that place high stresses on shoulder implants.

In my practice, I tend to view physiological age as a more important indicator than chronological age because my experience confirms what the study has above has found. Continue reading

Is rTSA the Solution to Every Patient’s Problem?

Howard Routman, DO

Read the complete study: Causes of poor postoperative improvement after reverse total shoulder arthroplasty

This study reviewed comorbidities and results for higher baseline American Shoulder and Elbow Surgeons (ASES) scores that are correlated with poor post-operative improvement. The study collected data from a total of 150 patients who underwent reverse total shoulder arthroplasty (rTSA) from 2007-2013. A minimum of two-year post-operative ASES scores were included, and poor post-op improvement was defined as a change of ASES score of less than 12 points. Out of the 150 patients, male gender, presence of an intact rotator cuff at the time of surgery, depression, a higher baseline ASES score and higher total number of medical comorbidities were associated with poor post-operative improvement after rTSA. Neither patient age, nor indication for surgery, was found to correlate with poor improvement after rTSA. In general, the study population was older, with an average age of 71.6 +/- 8.8, and the majority of patients were female.

Literature Review:

It should be noted that as the number of rTSAs continues to grow rapidly—due to its success in improving pain and function in most patients—some patients fail to improve clinically. Interestingly, the article also mentioned that patient satisfaction is now frequently linked to hospital and physician reimbursements. This study emphasizes reasons for poor post-operative improvement throughout with baseline pulled  from ASES scores and patient data. Physical examination findings were not a focused component of the analysis.

The temptation to view the rTSA as a panacea that can fix everything is high.  We need to temper our enthusiasm and ensure that we select our patients wisely.

When managing expectations with higher pre-operative ASES scores, I don’t really look at an ASES score pre-operatively as a screening tool, but I appreciate the concept of the ‘delta’ of improvement before surgery.  If a patient’s radiograph shows a classic cuff tear arthropathy, and the patient has maintained overhead elevation and mild pain, the change in function and pain that can be provided with a perfect reverse is minimal.  Ideally, patient selection can help us identify who best benefits from rTSA.  By limiting the indications to patients who cannot elevate beyond 90⁰, and who identify themselves has having quality-of-life-altering pain, we can skew our delta favorably.  The article referenced a study by Wall et al that noted patients who underwent rTSA for primary osteoarthritis had much smaller improvements in range of motion compared with patients who underwent rTSA for rotator cuff tear arthropathy or massive tears. Current expectations for improving post-operative function versus outcomes in patients with high levels of pre-operative function are to be noted.

In a cohort of 31 of my rTSA patients, the average post op ASES score was 82.68 (+/- 18.4), compared to 76 +/- 16.7 as mentioned in the study. Continue reading

Can Sufficient Internal Rotation Be Achieved with Bilateral rTSA?

Thomas Wright, MD

Read complete study: Risk of insufficient internal rotation after bilateral reverse shoulder arthroplasty: clinical and patient reported outcome in 57 patients.

This study focused on the effects and risks of bilateral reverse shoulder arthroplasty (rTSA) on internal rotation (IR) in 57 patients. Data was recorded up to two years after the second surgery. The study found that only 15 percent of patients had insufficient IR in both shoulders after 12 months and 5 percent after 24 months. Patients who had insufficient baseline IR in their second shoulder and insufficient IR 12 month post op after their first shoulder had a 100 percent risk of having insufficient IR in both shoulders. The conclusion of this article is a recommendation to use staged bilateral rTSA over the use of a hemiathroplasty. The authors found that the majority of patients would undergo the surgery again, as it does provide benefits, like reduction in pain, regardless of the issues with IR.

Literature Review:

The authors of this study focused on the risks of staged bilateral rTSA on internal rotation. I agree with their concern, as bilateral decreased IR could result in difficulties with toileting. In my practice, I stage my bilateral cases; however the timing is up to the patient. I will proceed with the second surgery no sooner than 12 weeks, but I do not recommend waiting as long as a year. In 2014, we published an article on bilateral rTSA1 in which we found all patients eventually had enough IR to allow toileting with at least one shoulder. I agree with the authors and do not recommend using a hemiarthroplasty in the second shoulder, based on the positive results that we had with rTSA.

Although the article showed a 100 percent failure rate in achieving sufficient IR in the second shoulder when it comes to patients who have both insufficient baseline IR and insufficient IR 12 months post op in their first shoulder, we have not noted that to be a problem.

One example is a 79 year old male with symptomatic cuff tear arthropathy on the right and a failed total shoulder arthroplasty (TSA) on the left due to rotator cuff insufficiency.Because of the predictable nature of performing an rTSA as a primary, the right side was addressed first. At three months post-op he had IR to L5.

Figure_1

79 year old male, cuff tear arthropathy on the right side, 3 months post op

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Patient-Specific Guides with a Custom Implant: Is This a Practical Solution?

Joseph Zuckerman, MD

Read complete study: A patient Specific guide for Optimizing custom made glenoid implantation in cases of severe glenoid defects.

These authors studied the ability to implant a custom glenoid component in 10 cadaver glenoids with glenoid defects using patient-specific guides and traditional non-guided techniques. The use of the patient-specific guide reduced angular deviations from the plan and significantly improved the position and length of the screw placements when used to implant the custom made glenoid components.

Literature Review:

The authors have focused on a well-known challenge in shoulder arthroplasty – treatment of the deformed glenoid during anatomic or reverse shoulder arthroplasty. There is no doubt that two approaches canbe developed to address this issue. The first is the use of patient-specific guides (or intraoperative positioning devices) to improve the accuracy of component placement. We all recognize that a properly placed glenoid component will have longer-term survival than a malpositioned component. The second approach is to have non-standard glenoid components available to address the deformity. These can be either custom-made implants specific for the patient being treated or augmented “off the shelf” implants that address the common deformities encountered.

I have found that using non-custom or “off the shelf” augmented glenoid components have addressed many of the bone-loss issues I have encountered.

The authors actually combine both approaches – they use a custom implant with a specimen-specific guide. This could be perceived as the “best of both” but in actuality it is quite impractical from a cost perspective. The incremental cost of a custom implant combined with a CT-generated, patient-specific guide would add significant incremental cost. In 2016, regardless of where the surgery is being performed in the world, it is a surgeon’s responsibility to consider cost, especially in the context of cost vs. potential benefit. In addition, the FDA has been very strict on the use of custom implant components, which leaves us surgeons limited options for this approach. Continue reading