Background The substantial increase in the utilization of shoulder arthroplasty in the United States during the past decade is partly attributable to the growing acceptance of reverse shoulder ...arthroplasty (RSA). This study compared the national utilization of and indications for shoulder hemiarthroplasty, total shoulder arthroplasty (TSA), and RSA. Methods The Nationwide Inpatient Sample was used to identify shoulder arthroplasty procedures performed in the United States in 2011. Indicating diagnoses, demographics, and hospital characteristics were identified for each shoulder arthroplasty procedure. Multivariable regression identified factors associated with long hospital stays. Results An estimated 66,485 shoulder arthroplasty procedures were identified (33% RSA, 44% TSA, and 23% hemiarthroplasty). Common diagnoses for RSA were rotator cuff tear and arthritis (80%) and proximal humerus fracture (10%). TSA was performed for osteoarthritis in 93% of cases. Hemiarthroplasty was performed for osteoarthritis (45%) and proximal humerus fracture (38%). One quarter of proximal humerus fractures treated with arthroplasty received RSA compared with 69.8% that underwent hemiarthroplasty. Mortality occurred in 0.08% of patients with atraumatic diagnoses but in 0.53% of patients with proximal humerus fractures ( P < .001). Older patients with comorbidities often had longer hospital stays, as did those with government insurance. Conclusions RSAs accounted for one third of all shoulder arthroplasty procedures in the United States in 2011. Whereas the majority of RSAs are performed for rotator cuff tear arthropathy, one quarter of proximal humerus fractures are treated with RSA, suggesting the strong uptake of this relatively new procedure in the United States.
Background Malnutrition is an established risk factor for postoperative complications. The purpose of this investigation was to determine the overall prevalence of malnutrition in total shoulder ...arthroplasty (TSA) patients, the differences in prevalence across obesity subgroups, and the overall complication risk of malnourished patients compared with normal patients. Methods The American College of Surgeons National Surgical Quality Improvement Program database was queried for TSA cases from 2005 to 2013 for this retrospective cohort study. Malnutrition was defined as preoperative albumin concentration of <3.5 g/dL. Rates of postoperative complications were compared between normal and malnourished patients. Results We identified 4,655 TSA cases, with preoperative albumin measurements available for 1681 patients (36.1%). Propensity score adjustment successfully reduced selection bias, with adjusted P values of >.05 for demographics, body mass index, and modified Charlson Comorbidity Index. Of the cohort with albumin measurements, 7.6% of patients were malnourished according to our criteria. Bivariate analysis showed malnourished patients had higher rates of pulmonary complications, anemia requiring transfusion, extended length of stay (LOS), and death (all P < .05). Propensity-adjusted multivariable logistic regression demonstrated that malnutrition was significantly associated (all P < .05) with postoperative transfusion (odds ratio, 2.49), extended LOS (odds ratio, 1.69), and death (odds ratio, 18.09). Conclusion The overall prevalence of malnutrition was 7.6%. Malnourished patients were at a significantly increased risk for blood transfusion, longer hospital LOS, and death within 30 days of surgery. Multivariable analysis showed TSA patients with preoperative albumin levels of <3.5 g/dL are at much higher risk for morbidity and death after surgery than patients with albumin levels within normal reference ranges.
Background Whereas most proximal humerus fractures are treated nonoperatively, complex 3- and 4-part fractures may require shoulder arthroplasty. Hemi-shoulder arthroplasty (HSA) has been the ...standard treatment, but recently there has been discussion and utilization of reverse total shoulder arthroplasty (RTSA) as a viable treatment option. This study evaluated the national utilization of RTSA and HSA for proximal humerus fractures and compared patient and hospital characteristics associated with each procedure. Methods This study used the Nationwide Inpatient Sample database for 2011, which allows national estimates of inpatient hospital discharges. Patients were selected by diagnosis and procedure codes to identify those who underwent RTSA or HSA for treatment of proximal humerus fractures. Patient and hospital characteristics associated with each procedure as well as in-hospital complication rates were identified. Results An estimated 7714 patients with proximal humerus fractures were selected, 27.4% of whom were treated with RTSA. Except for increased age, patient characteristics were similar between groups, as were complication rates. RTSA was more likely to be performed over HSA in small, rural, nonteaching hospitals and also in those that had already adopted and performed a high volume of RTSA procedures for other diagnoses. Conclusions Although HSA remains the most common arthroplasty choice for proximal humerus fractures, RTSA is becoming widely used. Patient characteristics and complications were similar between the 2 procedures, and as clinical evidence appears to show improved outcomes with RTSA, it is likely that acceptance of RTSA will continue to grow.
Introduction Patients may experience a loss of internal rotation (IR) and external rotation (ER) after reverse total shoulder arthroplasty (RTSA). We hypothesized that alterations in the glenosphere ...position will affect the amount of impingement-free IR and ER. Materials and methods Computed tomography (CT) scans of the scapula and humerus were obtained from 7 cadaveric specimens, and 3-dimensional reconstructions were created. RTSA models were virtually implanted into each specimen. The glenosphere position was determined in relation to the neutral position in 7 settings: medialization (5 mm), lateralization (10 mm), superior translation (6 mm), inferior translation (6 mm), superior tilt (20°), and inferior tilt (15° and 30°). The humerus in each virtual model was allowed to freely rotate at a fixed scaption angle (0°, 20°, 40°, and 60°) until encountering bone-to-bone or bone-to-implant impingement (180° of limitation). Measurements were recorded for each scaption angulation. Results At 0° scaption, only inferior translation, lateralization, and inferior tilt (30°) allowed any impingement-free motion in IR and ER. At the midranges of scaption (20° and 40°), increased lateralization and inferior translation resulted in improved rotation. Supraphysiologic motion (>90° rotation) was seen consistently at 60° of scaption in IR. Superior translation (6 mm) resulted in no rotation at 0° and 20° of scaption for IR and ER. Conclusions Glenosphere position significantly affected humeral IR and ER after RTSA. Superior translation resulted in significant restrictions on IR and ER. Optimal glenosphere positioning was achieved with inferior translation, inferior tilt, and lateralization in all degrees of scaption.
Background Although reverse total shoulder arthroplasty (RTSA) has been successful in improving pain and function in most patients, some patients fail to improve clinically. The present study used a ...large registry of RTSA patients to evaluate associations between patient-related factors and poor postoperative improvement after RTSA. Materials and methods A prospectively collected shoulder arthroplasty registry was queried for consecutive patients who underwent RTSA from 2007 to 2013. Patients with baseline and minimum 2-year postoperative American Shoulder and Elbow Surgeons (ASES) scores were included. Poor postoperative improvement was defined as a change in the ASES of less than 12 points. Multivariate logistic regression analysis was used to identify independent risk factors. Results A total of 150 patients met inclusion and exclusion criteria. Logistic regression revealed that male sex (adjusted odds ratio OR, 7.9; P = .004), presence of an intact rotator cuff at the time of surgery (adjusted OR, 4.8; P = .025), depression (adjusted OR, 11.2; P = .005), a higher baseline ASES score ( P < .001), and higher total number of medical comorbidities ( P = .035) were associated with poor postoperative improvement after RTSA. Conclusions Surrogates for better preoperative function after RTSA, such as a higher baseline ASES score and intact rotator cuff at the time of surgery, correlated with poor postoperative improvement. In addition, male sex, depression, and total number of medical comorbidities also correlated with poor postoperative improvement. Interestingly, factors such as patient age and indication for surgery were not found to correlate with poor improvement after RTSA.
Background No evaluation has been done on the relationship of the critical shoulder angle (CSA) with retear after rotator cuff repair. Our purpose was to evaluate whether a higher CSA is associated ...with retear after rotator cuff repair. Methods This was a retrospective review of 76 patients who had undergone rotator cuff repair with postoperative ultrasound examination. Ultrasound findings were graded no retear (NT), partial-thickness (PT) retear, or full-thickness (FT) retear. Preoperative radiographs were used to measure CSA, glenoid inclination, lateral acromion angle, and acromion index. Results Average age was 61.9 years (45.3-74.9 years). On ultrasound examination, 57 shoulders (74.0%) had NT, 11 (14.2%) had PT retears, and 8 (10.3%) had FT retears. There was no significant difference in retear rate by age, gender, or tension of repair. Average CSA was significantly lower for the NT group at 34.3° ± 2.9° than for the FT group at 38.6° ± 3.5° ( P < .01). If CSA was >38°, the odds ratio of having an FT retear was 14.8 ( P < .01). In addition, higher CSA inversely correlated with postoperative American Shoulder and Elbow Surgeons scores ( P < .03). Average glenoid inclination was significantly lower in the NT group at 12.3° ± 2.7° compared with 17.3° ± 2.6° in the FT group ( P < .01). If glenoid inclination was >14, the odds ratio of having a FT retear was 15.0 ( P < .01). Conclusion At short-term follow-up, higher CSA significantly increased the risk of an FT retear after rotator cuff repair. Also, increasing CSA correlated with worse postoperative American Shoulder and Elbow Surgeons scores. This radiographic marker may help manage expectations for rotator cuff tear patients.
Background Shoulder hemiarthroplasty (HA) has been the standard treatment for complex proximal humerus fractures in the elderly requiring surgery but not amenable to fixation. Reverse total shoulder ...arthroplasty (RTSA) has also emerged as a costly albeit highly effective alternative. The purpose of this study was to compare the cost-effectiveness of nonoperative fracture care, HA, and RTSA for complex proximal humerus fractures from the perspective of both U.S. payors and hospitals. Methods A Markov model was constructed for the treatment alternatives. Costs were expressed in 2013 U.S. dollars and effectiveness in quality-adjusted life-years (QALYs). The principal outcome measure was incremental cost-effectiveness ratio (ICER). Sensitivity analyses were performed to evaluate model assumptions. Results In the base case, from the payor perspective, RTSA was associated with an ICER of $8100/QALY; HA was eliminated from payor analysis as a cost-ineffective strategy. From the hospital perspective, however, HA was not cost-ineffective and the ICER for HA was $36,700/QALY, with RTSA providing incremental effectiveness at $57,400/QALY. RTSA was the optimal strategy in 61% and 54% of payor and hospital probabilistic sensitivity analyses, respectively. The preferred strategy was dependent on associated QALY gains, primary RTSA cost, and failure rates for RTSA. Conclusions RTSA can be a cost-effective intervention in the surgical treatment of complex proximal humerus fractures. HA can also be a cost-effective intervention, depending on the cost perspective (cost-ineffective for payor but cost-effective for the hospital). This analysis highlights the opportunities for increased cost-sharing strategies to alleviate the cost burden on hospitals.
Background Reverse total shoulder arthroplasty offers pain relief and functional improvement for patients with rotator cuff–deficient shoulders. The purpose of this study was to determine the optimal ...amount of humeral retroversion for this prosthesis. Materials and methods Six cadaveric shoulders underwent computed tomography (CT) imaging and were then dissected of soft tissues, except for their tendinous attachments. A reverse total shoulder arthroplasty was implanted in 0°, 20°, 30°, and 40° of retroversion, and the shoulders were mounted on a simulator to determine the muscle forces required to achieve 30° and 60° of scaption. CT images were converted into 3-dimensional models, and the amount of internal and external rotation was determined with computer modeling at various scaption angles. Results No differences were found in the forces required for 30° or 60° of scaption for any muscle, at any retroversion. With increasing retroversion, more impingement-free external rotation was obtained, with a concomitant decrease in the amount of internal rotation. Above 60°, the humerus was allowed to rotate around the glenosphere unencumbered. Conclusions Increasing retroversion did not affect the muscle force requirements for scaption across the shoulder. Placing the humeral component in 0° to 20° of retroversion allows maximum internal rotation with the arm at the side, a movement that is required for daily activities. This limits external rotation with the arm at the side, but has no effect on external rotation with the arm elevated.
Hypothesis and background The purpose of this study was to compare the accuracy of patient-specific guides for total shoulder arthroplasty (TSA) with traditional instrumentation in arthritic cadaver ...shoulders. We hypothesized that the patient-specific guides would place components more accurately than standard instrumentation. Materials and methods Seventy cadaver shoulders with radiographically confirmed arthritis were randomized in equal groups to 5 surgeons of varying experience levels who were not involved in development of the patient-specific guidance system. Specimens were then randomized to patient-specific guides based off of computed tomography scanning, standard instrumentation, and anatomic TSA or reverse TSA. Variances in version or inclination of more than 10° and more than 4 mm in starting point were considered indications of significant component malposition. Results TSA glenoid components placed with patient-specific guides averaged 5° of deviation from the intended position in version and 3° in inclination; those with standard instrumentation averaged 8° of deviation in version and 7° in inclination. These differences were significant for version ( P = .04) and inclination ( P = .01). Multivariate analysis of variance to compare the overall accuracy for the entire cohort (TSA and reverse TSA) revealed patient-specific guides to be significantly more accurate ( P = .01) for the combined vectors of version and inclination. Patient-specific guides also had fewer instances of significant component malposition than standard instrumentation did. Conclusion Patient-specific targeting guides were more accurate than traditional instrumentation and had fewer instances of component malposition for glenoid component placement in this multi-surgeon cadaver study of arthritic shoulders. Long-term clinical studies are needed to determine if these improvements produce improved functional outcomes.
The effect of obesity in shoulder arthroplasty has been recently reported in the literature with different and conflicting results. This review analyzes the role of obesity on outcomes and ...complications in shoulder arthroplasty. Morbid obesity (body mass index >40 kg/m2 ), more than standard obesity, is associated with a longer operative time, higher complication rate, reoperation rate and superficial infection. Obesity does not have a detrimental effect on functional outcomes. The magnitude of functional improvement in obese patients, however, can be inferior to that in nonobese patients. Obesity and morbid obesity do not increase hospital charges.
