Value comparison of humeral component press-fit and cemented techniques in reverse shoulder arthroplasty

Cemented vs. press-fit humeral stems: a matched cohort analysis at a mean follow-up of 10 years

BACKGROUND

Although cementation of humeral stems has long been considered the gold standard for anatomic shoulder arthroplasty (aTSA), cementless, or press-fit, fixation offers a relatively cheaper and less demanding alternative, particularly in the setting of a revision procedure. However, this approach has been accompanied by concerns of implant loosening and high rates of radiolucency. In the present study, we performed a propensity-matched comparison of clinical and patient-reported outcomes between cemented and cementless fixation techniques for aTSA. We hypothesized that cemented fixation of the humeral component would have significantly better implant survival while providing comparable functional outcomes at final follow-up.

METHODS

This study was a retrospective comparison of 50 shoulders undergoing aTSA: 25 using cemented humeral fixation vs. 25 using press-fit humeral fixation. Patients in the 2 groups were propensity matched according to age, sex, and preoperative American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) score. Primary outcome measures included range of motion (ROM) (forward elevation, external rotation, internal rotation), patient-reported outcomes (ASES, Simple Shoulder Test [SST], visual analog scale [VAS]), and implant survival.

RESULTS

At baseline, the 2 fixation groups were similar in regard to age, sex, body mass index, preoperative ASES score, and surgical indication. Mean follow-up was 11.7 ± 4.95 years in the cemented cohort and 9.13 ± 3.77 years in the press-fit cohort (P = .045). Both groups demonstrated significant improvements postoperatively in all included ROM and patient-reported outcomes. However, press-fit patients reported significantly better VAS, ASES, and SST scores. Mean VAS pain score was 1.1 ± 1.8 in press-fit patients and 3.2 ± 3.0 in cemented patients (P = .005). The mean ASES score was 87.7 ± 12.4 in press-fit patients and 69.5 ± 22.7 in cemented patients (P = .002). Lastly, the mean SST score was 9.8 ± 3.1 in press-fit patients and 7.7 ± 3.7 in cemented patients (P = .040). Both fixation techniques provided lasting implant survivorship with only a single revision operation in each of the cohorts.

CONCLUSION

Herein, we provide a propensity-matched, long-term comparison of patients receiving anatomic shoulder arthroplasty stratified according to humeral stem fixation technique. The results of this analysis illustrate that both types of humeral fixation techniques yield durable and significant improvements in shoulder function with similar rates of survival at 10 years of follow-up.

The variability of MCID, SCB, PASS, and MOI thresholds for PROMs in the reverse total shoulder arthroplasty literature: a systematic review

BACKGROUND

Reverse total shoulder arthroplasty (RTSA) is a common procedure utilized to address degenerative pathologies of the glenohumeral joint and rotator cuff. Increased reliance on patient-reported outcome measures (PROMs) have placed emphasis on the utilization of the minimum clinically important difference (MCID), substantial clinical benefit (SCB), patient acceptable symptom state (PASS), and maximal outcome improvement (MOI) thresholds to assess the clinical efficacy of RTSA. In this study, we systematically reviewed the MCID, SCB, PASS, and MOI thresholds reported for PROMs following RTSA.

METHODS

PubMed, Embase, MEDLINE, Cochrane Library, and Google Scholar were queried for articles from January 1, 2000 to August 31, 2023 reporting MCID, SCB, PASS, or MOI values for PROMs following RTSA. Patient demographic data, study characteristics, MCID/SCB/PASS/MOI thresholds, and threshold calculation methods were extracted.

RESULTS

One hundred and forty-one articles were screened with 39 ultimately included, comprising 11,984 total patients that underwent RTSA. 34 (87%) studies reported MCID thresholds, 20 (51%) reported SCB, 5 (13%) reported PASS, and 2 (5%) reported MOI. 25/39 (64%) studies referenced a previous study when reporting MCID, SCB, PASS, or MOI values, 11 (28%) used an anchor-based method to calculate threshold values, 1 (3%) used a distribution-based method, and 2 (5%) used both anchor and distribution methods. There were 19 newly calculated MCID (11), SCB (5), PASS (1), and MOI (2) thresholds. For 5 of the 6 most utilized PROMs (ASES, SST, Constant, UCLA, and SPADI), the range of reported MCID values exceeded 50% of the most common threshold. For 3 of 6, the range of SCB values exceeded 25% of the most common threshold.

CONCLUSION

There is substantial variability in the MCID and SCB threshold values reported in the RTSA literature. Standardizing the methodologic calculation and utilization of MCID, SCB, PASS, and MOI thresholds for RTSA may allow for improved assessment of PROMs.

Do the humeral radiographic changes at 5-year follow-up affect the clinical outcomes of press-fit humeral stems in primary reverse shoulder arthroplasties?

INTRODUCTION

The purposes of this study were to analyze and compare the functional outcomes and radiological changes around the press-fit humeral components in two contemporary medialized reverse total shoulder arthroplasty (RTSA) systems at a minimum of 5-year follow-up.

MATERIALS AND METHODS

Between December 2003 and December 2015, 249 consecutive RTSAs were performed at our hospital. Of these, 68 primary uncemented RTSA met our inclusion criteria. The Constant-Murley score (CMS), the modified Constant score, a visual analog scale (VAS) and active shoulder range of motion (ROM) were measured pre- and postoperatively. Radiological assessment was performed by plain radiographs at a minimum of 5 years postoperatively.

RESULTS

At a mean follow-up of 80.2 months, there was no significant difference (p = .59) between the postoperative functional scores and range of motion of the two groups (Delta Xtend and Lima SMR). Radiological data of stress-shielding were observed in 38 patients (55.9%) being slightly more frequent in the Lima SMR group (21 patients) than in the Delta Xtend group (17 patients) (p = .62).

CONCLUSIONS

Our study shows that the good functional results are similar between the two uncemented RTSA systems used and that they do not depend on the presence of radiological changes (stress-shielding) in the humeral stem at a minimum 5-year follow-up.

Quantifying success after anatomic total shoulder arthroplasty: the minimal clinically important percentage of maximal possible improvement

INTRODUCTION

Changes in pre- to postoperative outcome scores are often used to quantify success after anatomic total shoulder arthroplasty (aTSA). However, ceiling effects associated with many outcome scores limit the ability to differentiate success among high-functioning patients. The percentage maximal possible improvement (%MPI) was introduced to better stratify patient success; however, it is unclear if the 30% threshold first proposed correlates with perceived patient success across all outcome scores. The purpose of this study was to compare the proportion of patients that achieved the minimal clinically important difference (MCID) and %MPI for different outcome scores and to define the %MPI thresholds associated with patient satisfaction following primary aTSA.

METHODS

A retrospective review was performed of an international shoulder arthroplasty database between 2003 and 2020. All primary aTSAs performed using a single implant system with minimum 2-year follow-up were reviewed. Pre- and postoperative outcome scores were evaluated for all patients to calculate improvement. The proportion of patients achieving the MCID and 30% MPI were determined for each outcome score. Thresholds for the minimal clinically important %MPI (MCI-%MPI) were calculated using an anchor-based method for each outcome score and stratified by age and sex.

RESULTS

1593 shoulders with a mean follow-up of 59.3 months were included. Outcome scores with known ceiling effects (Simple Shoulder Test [SST], American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form [ASES], University of California-Los Angeles shoulder score [UCLA]) had higher rates of patients achieving the 30% MPI but not the previously reported MCID. Inversely, outcome scores without significant ceiling effects (Constant and Shoulder Arthroplasty Smart [SAS] scores) had higher rates of patients achieving the MCID but not the 30% MPI. The MCI-%MPI differed among outcome scores, and mean values were as follows: 33% for the SST, 24% for the Constant score, 32% for the ASES score, 38% for the UCLA score, 30% for the Shoulder Pain and Disability Index score, and 33% for the SAS score. The MCI-%MPI increased with greater age (P < .003) and females had thresholds greater than or equal to males for all scores assessed, meaning that patients with higher thresholds required a greater fraction of the possible improvement for a given score to be satisfied.

CONCLUSION

The %MPI offers a simple method to quickly assess improvements across patient outcome scores. However, the %MPI that represents patient improvement after surgery is not uniformly the previously established 30% threshold. Surgeons should use score-specific estimates of the MCI-%MPI to gauge success when evaluating patients undergoing primary aTSA.

Substantial Inconsistency and Variability Exists Among Minimum Clinically Important Differences for Shoulder Arthroplasty Outcomes: A Systematic Review

BACKGROUND

As the value of patient-reported outcomes becomes increasingly recognized, minimum clinically important difference (MCID) thresholds have seen greater use in shoulder arthroplasty. However, MCIDs are unique to certain populations, and variation in the modes of calculation in this field may be of concern. With the growing utilization of MCIDs within the field and value-based care models, a detailed appraisal of the appropriateness of MCID use in the literature is necessary and has not been systematically reviewed.

QUESTIONS/PURPOSES

We performed a systematic review of MCID quantification in existing studies on shoulder arthroplasty to answer the following questions: (1) What is the range of values reported for the MCID in commonly used shoulder arthroplasty patient-reported outcome measures (PROMs)? (2) What percentage of studies use previously existing MCIDs versus calculating a new MCID? (3) What techniques for calculating the MCID were used in studies where a new MCID was calculated?

METHODS

The Embase, PubMed, and Ovid/MEDLINE databases were queried from December 2008 through December 2020 for total shoulder arthroplasty and reverse total shoulder arthroplasty articles reporting an MCID value for various PROMs. Two reviewers (DAK, MAM) independently screened articles for eligibility, specifically identifying articles that reported MCID values for PROMs after shoulder arthroplasty, and extracted data for analysis. Each study was classified into two categories: those referencing a previously defined MCID and those using a newly calculated MCID. Methods for determining the MCID for each study and the variability of reported MCIDs for each PROM were recorded. The number of patients, age, gender, BMI, length of follow-up, surgical indications, and surgical type were extracted for each article. Forty-three articles (16,408 patients) with a mean (range) follow-up of 20 months (0.75 to 68) met the inclusion criteria. The median (range) BMI of patients was 29.3 kg/m2 (28.0 to 32.2 kg/m2), and the median (range) age was 68 years (53 to 84). There were 17 unique PROMs with MCID values. Of the 112 MCIDs reported, the most common PROMs with MCIDs were the American Shoulder and Elbow Surgeons (ASES) (23% [26 of 112]), the Simple Shoulder Test (SST) (17% [19 of 112]), and the Constant (15% [17 of 112]).

RESULTS

The ranges of MCID values for each PROM varied widely (ASES: 6.3 to 29.5; SST: 1.4 to 4.0; Constant: -0.3 to 12.8). Fifty-six percent (24 of 43) of studies used previously established MCIDs, with 46% (11 of 24) citing one study. Forty-four percent (19 of 43) of studies established new MCIDs, and the most common technique was anchor-based (37% [7 of 19]), followed by distribution (21% [4 of 19]).

CONCLUSION

There is substantial inconsistency and variability in the quantification and reporting of MCID values in shoulder arthroplasty studies. Many shoulder arthroplasty studies apply previously published MCID values with variable ranges of follow-up rather than calculating population-specific thresholds. The use of previously calculated MCIDs may be acceptable in specific situations; however, investigators should select an anchor-based MCID calculated from a patient population as similar as possible to their own. This practice is preferable to the use of distribution-approach MCID methods. Alternatively, authors may consider using substantial clinical benefit or patient-acceptable symptom state to assess outcomes after shoulder arthroplasty.

CLINICAL RELEVANCE

Although MCIDs may provide a useful effect-size based alternative to the traditional p value, care must be taken to use an MCID that is appropriate for the particular patient population being studied.

Clinical results and radiological bony adaptations on a cementless short-stem prosthesis - A comparative study between anatomical and reverse total shoulder arthroplasty

INTRODUCTION

Although the use of short stem and stemless shoulder prosthesis is trending, the surgical outcome may vary due to varying biomechanics. Objectives were to evaluate and compare the short-term clinical results and radiological changes between anatomical total shoulder arthroplasty (TSA) and reverse TSA (rTSA) with a short-stem humeral design.

HYPOTHESIS

There is no clinical and radiological difference between TSA and rTSA using a short-stem humeral design.

METHODS

This retrospective study included 66 patients who underwent TSA and rTSA (33 patients each) with a minimum 2-year follow-up. Radiographic findings, including preoperative Tingart cortical index (TCI), postoperative filling ratios of metaphysis (FRmet) and diaphysis (FRdia), bone adaptations, and osteolysis around the humeral stem at the immediate postoperative period, and the most recent follow-up were measured. Pre and postoperative Constant-Murley score, subjective shoulder value (SSV), and complications were noted.

RESULTS

At a mean follow-up of 27 (range 24-50) months, FRmet was significantly higher in rTSA group than the TSA group (0.65 vs. 0.60, p=0.009). Bone resorption was similar in both groups (p=0.76) and was correlated to a lower TCI value of<2.9mm (p=0.02). Despite significant clinical improvement in individual groups, the comparison between groups was non-significant (p>0.05). Negative correlation was observed between TCI and total clinical score (p=0.045) in TSA group, active external rotation (p=0.019), activity (p=0.005), SSV (p=0.008) and total score (p=0.025) in rTSA group. Radiographic changes were not influenced by patient characteristics and clinical results (p>0.05).

CONCLUSION

Although no radiographic difference was observed between TSA and rTSA, better short-term clinical results observed with the usage of the short-stem humeral design prosthesis are encouraging.

LEVEL OF EVIDENCE

III; Retrospective cohort study.

Measuring Patient Value after Total Shoulder Arthroplasty

Evaluating the value of health care is of paramount importance to keep improving patients' quality of life and optimizing associated costs. Our objective was to present a calculation method based on Michael Porter's formula and standard references to estimate patient value delivered by total shoulder arthroplasty (TSA). We retrospectively reviewed the records of 116 consecutive TSAs performed between June 2015 and June 2019. Patient value was defined as quality of care divided by direct costs of surgery. Quality metrics included intra- and postoperative complications as well as weighted improvements in three different patient-reported outcome measures at a minimum of one-year follow-up. Direct costs of surgery were retrieved from the management accounting analyses. Substantial clinical benefit (SCB) thresholds and the standard reimbursement system were used as references for quality and cost dimensions. A multivariable linear regression was performed to identify factors associated with patient delivered value. Compared to a reference of 1.0, the quality of care delivered to patients was 1.3 ± 0.3 (range, 0.6-2.0) and the associated direct cost was 1.0 ± 0.2 (range, 0.7-1.6). Ninety patients (78%) had a quality of care ≥1.0 and 61 patients (53%) had direct costs related to surgery ≤1.0. The average value delivered to patients was 1.3 ± 0.4 (range, 0.5-2.5) with 91 patients (78%) ≥ 1.0, was higher for non-smokers (beta, 0.12; p = 0.044), anatomic TSA (beta, 0.53; p < 0.001), increased with higher pre-operative pain (beta, 0.08; p < 0.001) and lower pre-operative Constant score (beta, -0.06; p = 0.001). Our results revealed that almost 80% of TSAs provided substantial patient value. Patient pre-operative pain/function, tobacco use, and procedure type are important factors associated with delivered patient value.

Value Analysis of Anatomic and Reverse Shoulder Arthroplasty for Glenohumeral Osteoarthritis with an Intact Rotator Cuff

BACKGROUND

While anatomic total shoulder arthroplasty (TSA) has historically been considered the ideal treatment for end-stage glenohumeral osteoarthritis, reverse shoulder arthroplasty (RSA) has recently gained popularity. With substantial differences in implant design and cost between TSA and RSA, further investigation of outcomes and value is needed to support recent trends. The purpose of this study was to use the average and incremental cost-effectiveness ratio (ACER and ICER) and the procedure value index (PVI) to examine differences in outcomes and value between TSA and RSA for treatment of glenohumeral osteoarthritis with an intact rotator cuff.

METHODS

We performed a retrospective matched-cohort study of patients treated with primary shoulder arthroplasty for osteoarthritis with an intact rotator cuff who had a minimum 2-year follow-up. Outcome measures analyzed included the Simple Shoulder Test (SST), American Shoulder and Elbow Surgeons (ASES) questionnaire, visual analog scale (VAS) for pain, Single Assessment Numeric Evaluation (SANE), and overall satisfaction. Patients treated with TSA were matched 4:1 to those treated with RSA based on sex, age, and preoperative SST score. Value differences between TSA and RSA were calculated. Radiographs were analyzed for preoperative glenoid classification and postoperative radiolucent lines and gross loosening.

RESULTS

Two hundred and fifty-two TSA-treated patients were matched to 63 RSA-treated patients with no significant differences in sex, age, or preoperative SST score. Total hospitalization costs, charges, and reimbursements along with outcome improvements in units of minimal clinically important differences (MCIDs) and patient satisfaction did not differ between the groups. For RSA, the implant cost was significantly higher than that for TSA, but the operating room, anesthesia, and cement costs were lower. The TSA group had a 3.2% rate of gross glenoid loosening and a 2.4% revision rate. There was no loosening or revision in the RSA group. None of the value analytics differed between groups even after inclusion of the outcomes and costs of early TSA revisions.

CONCLUSIONS

TSA and RSA demonstrated similar outcomes and value when used to manage glenohumeral osteoarthritis with an intact rotator cuff.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Minimal Clinically Important Difference, Substantial Clinical Benefit, and Patient Acceptable Symptom State of Outcome Measures Relating to Shoulder Pathology and Surgery: a Systematic Review

PURPOSE OF THE REVIEW

To provide a comprehensive summary of available literature on the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptom state (PASS) of patient-reported outcome measures (PROMs) for various shoulder conditions and outcomes and to identify factors that influence these metrics.

RECENT FINDINGS

Over the past 2 years, there has been an increasing interest in utilizing MCID, SCB, and PASS as a gauge to evaluate the success of an intervention for shoulder conditions. Efforts at calculating these thresholds have yielded multiple and inconsistent values and are further compounded by the proliferation of different PROMs in the shoulder literature. The MCID, SCB, and PASS values of shoulder PROMs vary widely with study-specific characteristics, including patient demographics, shoulder pathology, treatment, shoulder instrument, study methodology, and calculation method. The differences in these factors are not inconsequential and could lead to large discrepancies in threshold values. It is crucial that clinicians are mindful of these variables when designing future studies to calculate these metrics or when utilizing previously published values to determine the success of an intervention.

The modern reverse shoulder arthroplasty and an updated systematic review for each complication: part II

Background

Globally, reverse shoulder arthroplasty (RSA) has moved away from the Grammont design to modern prosthesis designs. The purpose of this study was to provide a focused, updated systematic review for each of the most common complications of RSA by limiting each search to publications after 2010. In this part II, the following were examined: (1) instability, (2) humerus/glenoid fracture, (3) acromial/scapular spine fractures (AF/SSF), and (4) problems/miscellaneous.

Methods

Four separate PubMed database searches were performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Overall, 137 studies for instability, 94 for humerus/glenoid fracture, 120 for AF/SSF, and 74 for problems/miscellaneous were included in each review, respectively. Univariate analysis was performed with chi-square and Fisher exact tests.

Results

The Grammont design had a higher instability rate vs. all other designs combined (4.0%, 1.3%; P < .001), and the onlay humerus design had a lower rate than the lateralized glenoid design (0.9%, 2.0%; P = .02). The rate for intraoperative humerus fracture was 1.8%; intraoperative glenoid fracture, 0.3%; postoperative humerus fracture, 1.2%; and postoperative glenoid fracture, 0.1%. The rate of AF/SSF was 2.6% (371/14235). The rate for complex regional pain syndrome was 0.4%; deltoid injury, 0.1%; hematoma, 0.3%; and heterotopic ossification, 0.8%.

Conclusions

Focused systematic reviews of recent literature with a large volume of shoulders demonstrate that using non-Grammont modern prosthesis designs, complications including instability, intraoperative humerus and glenoid fractures, and hematoma are significantly reduced compared with previous studies. As the indications continue to expand for RSA, it is imperative to accurately track the rate and types of complications in order to justify its cost and increased indications.