Tag Archive | reverse total shoulder arthroplasty

Displaced Proximal Humeral Fractures: Fix or Replace?

Nonoperative management of proximal humerus fractures in the elderly used to be fairly common, but multiple studies have shown poor outcomes. Open reduction and internal fixation (ORIF) with locked-plate constructs has shown some promise, but it has been fraught with complications. Most recently, reverse total shoulder arthroplasty (rTSA) has emerged as a possible surgical solution, but this is a complicated procedure, and questions have arisen about long-term outcomes.  Compounding this conundrum are the varying degrees of severity of proximal humeral fractures.

In the March 18, 2020 issue of The Journal, Fraser et al. share 2-year results from a multicenter, single-blinded randomized trial that compared rTSA to ORIF for severely displaced proximal humeral fractures in patients 65 to 85 years of age. Included patients (n=124) had OTA/AO 11-B2 or 11-C2 fractures with >45° valgus or >30° varus in the anteroposterior view, or >50% displacement of the humeral head. Using the Constant shoulder score as the primary outcome measure, the authors demonstrated both a statistically significant and clinically meaningful difference favoring rTSA in this cohort.

The mean Constant score was 68.0 points for the rTSA group compared to 54.6 points for the ORIF group. The mean between-group difference, 13.4 points, was significant (p<0.001) and exceeded the minimal clinically important difference of 10 points.  The Constant-score difference between ORIF and rTSA was most pronounced (18.7 points) in patients with C2 fractures, but there was no significant score difference in those with B2 fractures. Secondary outcomes (Oxford Shoulder Scores) showed a consistent trend of the rTSA group scoring higher than the ORIF group at 2 years.

Although this study indicates an advantage for rTSA, one must consider that only severely displaced fractures were investigated and that 2-year follow-up for joint arthroplasty is considered short term. In a Commentary about this article, Peter A. Cole, MD points out that “if there was a 25% revision rate for reverse TSA at 5 to 10 years, then the superior results would be reversed, and we would be reinventing another wheel in orthopaedics.”

Clearly, longer-term studies in this population are a necessity, and Fraser et al. say they plan to follow these patients in 5-year intervals.

Matthew R. Schmitz, MD
JBJS Deputy Editor for Social Media

Volume-Outcome Relationships in Reverse TSA

In an OrthoBuzz post from early 2016, JBJS Editor-in-Chief Marc Swiontkowski, MD observed the following about volume-outcome relationships in total hip and total knee arthroplasty: “the higher the surgeon volume, the better the patient outcomes.”

Now, in a national database analysis of >38,200 patients who underwent a reverse total shoulder arthroplasty (RSA), Farley et al. find a similar inverse relationship between hospital volumes of this increasingly popular surgery and clinical outcomes. Reporting in the March 4, 2020 issue of JBJS, they found a similarly inverse relationship between hospital volume and resource utilization.

This study distinguishes itself with its large dataset and by crunching the data into specific hospital-volume strata for each category of clinical outcome (90-day complications, 90-day revisions, and 90-day readmissions) and resource-utilization outcome (cost of care, length of stay, and discharge disposition).

Specifically, on the clinical side, Farley et al. found the following:

  • A 1.42 times increased odds of any medical complication in the lowest-volume category (1 to 9 RSAs/yr) compared with the highest-volume category (≥69 RSAs/yr)
  • A 1.38 times increased odds of any readmission in the lowest-volume category (1 to 16 RSAs/yr) compared with the highest-volume category (≥70 RSAs/yr)
  • A 1.88 times increased odds of any 90-day revision in the lowest-volume category (1 to 16 RSAs/yr) compared with the highest-volume category (≥54 RSAs/yr)

Here are the findings from the resource-utilization side:

  • A 4.03 times increased odds of increased cost of care in the lowest-volume category (1 to 5 RSAs/yr) compared with the highest-volume category (≥106 RSAs/yr)
  • A 2.26 times increased odds of >2-day length of stay in the lowest-volume category (1 to 10 RSAs/yr) compared with the highest-volume category (≥106 RSAs/yr)
  • A 1.68 times increased odds of non-home discharge in the lowest-volume category (1 to 31 RSAs/yr) compared with the highest-volume category (≥106 RSAs/yr)

Farley et al. say hospital volume should be interpreted as a “composite marker” that is probably related to surgical experience, ancillary staff familiarity, and protocolized pathways. They “recommend a target volume of >9 RSAs/yr to avoid the highest risk of detrimental 90-day outcomes,” and they suggest that the outcome disparities could be addressed by “consolidation of care for RSA patients at high-performing institutions.”

Humeral Stem Retention in Revision Shoulder Arthroplasty

Reverse TSA for O'Buzz.jpegShoulder surgery for complex conditions such as irreparably large rotator cuff tears has been revolutionized by the concept of reverse total shoulder arthroplasty (rTSA). Improved design of rTSA implants by multiple manufacturers has resulted in excellent functional outcomes from these procedures. I have been educated by my shoulder colleagues to the fact that primary rTSA is actually technically less demanding than primary anatomic TSA because of greater exposure of the scapula/ glenoid anatomy.

When anatomic TSA clinically and/or radiographically fails, conversion to rTSA is an alternate to revision anatomic TSA. However, the more expensive and complex rTSA system can be difficult to implant in the revision scenario. In the May 3, 2017 issue of The Journal, Crosby et al. provide the outcomes of conversion from primary anatomic TSA to revision rTSA among two groups: those who originally received  a convertible-platform implant system, allowing the humeral stem to be retained during revision, and those whose revision required humeral stem exchange.

Patients with retained-stem revisions had significantly shorter operative times, lower estimated blood loss, lower intraoperative complication rates, and slightly better postoperative ROM. Although the authors caution that “the presence of a convertible-platform humeral component does not guarantee that it can be retained,” they conclude that the data from this study “support the use of a convertible-platform humeral stem when performing primary shoulder arthroplasty.”

Whenever possible, it’s a good idea to design implants where the portions that remain well-fixed can be retained and re-used for the rare revision situation. Such retained, modular parts can save resources, reduce operative time and patient morbidity, and may improve functional outcomes. However, we must be aware that issues with wear debris that have surfaced in modular hip components may also come into play with modular shoulder components.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

Reverse TSA Components Are Durable, But Patient Outcomes Decline Over a Decade

Reverse TSA for O'Buzz.jpegReverse total shoulder arthroplasty (RTSA) has yielded promising medium-term outcomes, but what about longer-term results? In the March 15, 2017 edition of The Journal, Bacle et al. look at patient outcomes, prosthetic survival, and complications after a mean follow up of 12.5 years.

The good-news finding from this study was that the overall prosthetic survival rate (using revision as the end point) was 93%, confirming the reliability of the Grammont-style prosthesis. Time, however, took its toll on other outcomes. For example, both mean and absolute Constant scores among the cohort decreased significantly compared with the scores at the medium-term follow up (a minimum of 2 years). The cumulative long-term complication rate was 29%, with 10 of the 47 complications occurring at a mean of 8.3 years. Seven of those 10 delayed complications were attributed to mechanical loosening.

The authors suggest that the deterioration of RTSA outcomes seen in this study “is probably related to patient aging coupled with bone erosion and/or deltoid impairment over time.” They conclude that long-term RTSA outcomes “may be impacted by both the etiology of the shoulder dysfunction and the time since implantation.”

For more peer-reviewed content related to RTSA from JBJS Essential Surgical Techniques, click on the following links:

 

JBJS Classics: Cuff-Tear Arthropathy Spurred Shoulder Prosthetic Technology

JBJS Classics Logo.pngOrthoBuzz regularly brings you a current commentary on a “classic” article from The Journal of Bone & Joint Surgery. These articles have been selected by the Editor-in-Chief and Deputy Editors of The Journal because of their long-standing significance to the orthopaedic community and the many citations they receive in the literature. Our OrthoBuzz commentators highlight the impact that these JBJS articles have had on the practice of orthopaedics. Please feel free to join the conversation by clicking on the “Leave a Comment” button in the box to the left.

Charles Neer II , a true pioneer in shoulder surgery, coined the term “cuff-tear arthropathy” in 1977. In a landmark 1983 JBJS publication, Dr. Neer, with coauthors Craig and Fukuda (both of whom became internationally recognized experts in shoulder surgery), reported on the pathophysiology and treatment of this previously little-recognized condition that was associated with long-standing massive rotator cuff tears.

Neer’s early work with total shoulder arthroplasty, also reported in JBJS, included a small cohort of patients with cuff-tear arthropathy. In the 1983 article on cuff-tear arthropathy, Neer and his coauthors described the pathologic presentation and treatment with total shoulder arthroplasty, along with a proposed pathophysiologic mechanism. They noted that, although it was a difficult procedure, their preferred treatment was “total shoulder replacement with rotator cuff reconstruction and special rehabilitation.”

Between 1975 and 1983, they surgically treated only 26 patients. Others later recognized that total shoulder replacement was associated with early glenoid failure and recommended treatment with humeral hemiarthroplasty.1 With either approach, success was limited by rotator cuff deficiency and dysfunction. The results were variable, with a small proportion having good outcomes and others achieving some pain relief and limited functional improvement.

Although it was not the first attempt at a reverse shoulder arthroplasty (RSA), Grammont developed an innovative design with improved implant technology and biomechanics to treat massive rotator cuff tears.2 This solved the biomechanical problem that resulted from a deficient rotator cuff and forever revolutionized the care of cuff-deficient shoulders. The Delta 3 prosthesis became available in Europe in the early 1990s but was not widely available in the US until 2004, when it was approved by the FDA.

Initially developed, approved, and used exclusively for cuff-tear arthropathy, early clinical success led to utilization for other conditions with deficient or dysfunctional rotator cuffs, including pseudoparalysis, revision shoulder arthroplasty, acute proximal humerus fractures, fracture sequelae, and chronic glenohumeral dislocations. The results have been so good that the indications have expanded beyond the initial recommendations for use only in elderly low-demand patients. Initial concerns were mollified by the apparent longevity and reported survivorship. Subsequently, there has been such a huge increase in utilization that RSA is approaching 50 percent of the US market share and some of the international market. The implications of expanded indications and increased utilization are yet to be seen.

In 1983, Neer and coauthors reported on what was then a relatively uncommon degenerative condition of the shoulder. Today, rotator cuff-deficient shoulders are much more common and can be better treated due to advances in our understanding of the pathophysiology and biomechanics of the condition, as well as advances in shoulder arthroplasty technology.

Andrew Green, MD
JBJS Deputy Editor

References
1. Franklin JL, Barrett WP, Jackins SE, Matsen FA 3rd. Glenoid loosening in total shoulder
arthroplasty. Association with rotator cuff deficiency. J Arthroplasty. 1988;3(1):39-46.

2. Grammont PM, Baulot E. Delta shoulder prosthesis for rotator cuff rupture. Orthopedics. 1993 Jan;16(1):65-8

JBJS Webinar: Managing Complex Proximal Humeral Fractures

PHF.gifProximal humeral fractures are the third most common occurring fracture in patients over the age of sixty-five years. These fractures are often difficult to accurately classify, and they can also be challenging to treat surgically.

On Tuesday, April 19, 2016 at 8:00 pm EDT, a complimentary webinar, hosted by The Journal of Bone & Joint Surgery, will present findings from two recent JBJS studies that explore the classification and treatment of complex proximal humeral fractures.

Milton Little, MD will examine whether 3D CT imaging helps orthopaedic surgeons classify proximal humeral fractures, and Derek J. Cuff, MD will analyze findings from a study that compared reverse total shoulder arthroplasty with hemiarthroplasty for treating these fractures in elderly patients.

Moderated by JBJS Deputy Editor Andrew Green, MD, the webinar will also feature commentaries on the study findings from shoulder experts Michael J. Gardner, MD and J. Michael Wiater, MD. The last 15 minutes of the webinar will be devoted to a live Q&A session.

Click here to register.

JBJS Reviews Editor’s Choice–All About the Glenoid

The number of total shoulder arthroplasties performed in the United States has increased substantially in the past decade. In fact, since 2006, more total shoulder arthroplasties have been performed than hemiarthroplasties. Because of this surge in the number of total shoulder arthroplasties being performed, various techniques have been developed to address glenoid bone loss in patients with arthritic shoulder conditions. Indeed, primary glenoid bone loss usually occurs in association with osteoarthritis and is characterized by posterior wear patterns, whereas secondary glenoid bone loss usually occurs in association with trauma, glenoid loosening, and iatrogenic injury during revision surgery.

In the July 2015 issue of JBJS Reviews, Gowda et al. review a number of important issues related to this condition, including normal glenoid anatomy, pathological changes in glenoid substance, primary glenoid bone loss, proper imaging studies for the evaluation of the glenoid, principles of glenoid restoration, and the effects of poor implant position. Other topics, such as glenoid bone-grafting, the use of augmented components, glenoid insert design, patient-specific instrumentation, and the emergence of reverse total shoulder arthroplasty as an important component of the armamentarium of the shoulder arthroplasty surgeon, are also addressed.

The authors assert that proper preoperative imaging is critical in order to ascertain glenoid characteristics, including size, version, and depth of the vault. The treatment of glenoid bone loss is dependent on the degree of version correction that is required and consists of eccentric reaming, bone or polyethylene augmentation, and, as noted above, the potential use of reverse shoulder arthroplasty.

In the future, shoulder arthroplasty research should evaluate the long-term outcomes of biomaterial-augmented glenoid components, the use of other materials (such as ceramics), the utility of fixation within the glenoid and endosteal vault, and the use of reverse-polarity implants.

Thomas A. Einhorn, MD

Editor, JBJS Reviews