Isometric strength, range of motion, and impairment before and after total and reverse shoulder arthroplasty.

BACKGROUND: Medicare Part A provides similar resources for coverage of inpatient hospitalization costs for patients treated with total shoulder arthroplasty (TSA) and reverse shoulder arthroplasty (RSA). This is based on an assumption that TSA and RSA are used to treat similar patient populations with comparable disease severity. However, no objective clinical information is available to support this resource allocation. The purpose of this study is to quantify the disease severity and subsequent improvement from primary TSA, primary RSA, and revision arthroplasty (TSA and RSA). METHODS: From March 2004 through May 2006, 174 shoulders (87 primary TSA, 55 primary RSA, and 32 revision cases) were prospectively studied using Biodex (Biodex Medical Systems, Shirley, NY, USA) isometric strength and standardized video range of motion measurements performed by an independent third-party observer at 1 week before surgery and at an average of 49 months (range, 32-69 months) postoperatively. Patient impairment ratings were calculated using the Florida Impairment Guidelines. RESULTS: Primary TSA had the lowest average preoperative impairment (21%), and revision arthroplasty had the highest (28%). All patients demonstrated improvement in the parameters tested. At an average 49 months, all 3 groups demonstrated a similar reduction in impairment ratings (TSA: 21% to 10%; RSA: 25% to 15%; revision arthroplasties: 28% to 20%). CONCLUSION: There are distinct differences in preoperative disease severity among patients undergoing primary TSA, primary RSA, and revision arthroplasty. Greater impairment is evident in patients undergoing a revision arthroplasty. However, all groups may be expected to achieve improvements and maintain these improvements 4 years postoperatively.

Preparing for the bundled-payment initiative: the cost and clinical outcomes of total shoulder arthroplasty for the surgical treatment of glenohumeral arthritis at an average 4-year follow-up.

BACKGROUND: The purpose of this study is to report on cost, outcomes, reliability, and safety of total shoulder arthroplasty (TSA) in patients with symptomatic glenohumeral joint arthritis. MATERIALS AND METHODS: Eighty-three primary TSA patients operated on at a single institution by a single surgeon were prospectively studied for a mean of 48 months (range, 32-69 months). For each patient, validated subjective and independently evaluated objective outcome measures were collected to determine clinical reliability of TSA. In addition, safety-defined as the lack of major complications-and direct costs specific to each patient were collected and analyzed. RESULTS: There were significant improvements (P < .01) in all clinical measures with the exception of the general health component of the Short Form 36 version 2. In addition, the majority of the patients met the criteria set forth for clinical reliability (76 of 83 [92%]) and safety (80 of 83 [96%]). The mean 4-year cost was $17,587, with the hospitalization accounting for 88% of this cost. Fiscal year was found to be responsible for the greatest fluctuation in total cost (P < .001). In addition, greater improvements in American Shoulder and Elbow Surgeons function scores (P = .022), higher preoperative social functioning scores on the Short Form 36 version 2 (P < .001), and female gender (P = .001) were correlated with lower cost. CONCLUSION: Before operative treatment, patients had moderate to severe shoulder pain and were limited in performing their activities. The mean 4-year cost of $17,587 allowed the purchase of treatment with TSA, leading to a greater than 5-fold reduction in pain and a nearly double improvement in shoulder function with a small risk of harm.

Reverse shoulder arthroplasty components and surgical techniques that restore glenohumeral motion.

BACKGROUND: Modifications in reverse shoulder arthroplasty (RSA) have been made with the intent of maximizing motion, although there is little objective evidence outlining their benefit. This study investigated the RSA component combinations that impart the greatest effect on impingement-free glenohumeral motion. METHODS: A previously validated virtual shoulder model was implanted with RSA components that varied by humeral implant type (inset/onset), glenosphere diameter (30, 36, and 42 mm), glenosphere placement (inferior/neutral), glenosphere center-of-rotation offset (0, 5, and 10 mm), humeral neck-shaft angle (130° and 150°), and humeral offset (zero, five, and ten mm). Motion was simulated in all technique combinations until the point of impingement in abduction, flexion/extension (F/E), and internal/external rotation (IR/ER). Regression analysis was used to rank combinations based on motion. RESULTS: Of 216 possible study combinations, 126 constructs (58%) demonstrated no arm-at-side impingement and were included for analysis. Models with the largest motion in abduction, F/E, and IR/ER, respectively, were inset-42-inferior-10-150-zero (107°), inset-36-inferior-10-130-five (146°), and inset-42-inferior-10-130-ten (121°). Humeral neck-shaft angle, glenosphere center-of-rotation offset, glenosphere placement, and glenosphere diameter had a significant effect on motion in all planes tested. Of these variables, humeral neck-shaft angle was most predictive of a change in abduction and F/E motion, whereas glenosphere placement was most predictive of a change in IR/ER motion. CONCLUSION: Higher glenosphere center-of-rotation offsets led to an increase in motion in all planes. To maximize motion in abduction, a valgus humeral component should be selected; to maximize F/E, a varus humeral component should be selected; and, to maximize IR/ER, the glenosphere should be placed inferiorly.

Preparing for the bundled-payment initiative: the cost and clinical outcomes of reverse shoulder arthroplasty for the surgical treatment of advanced rotator cuff deficiency at an average 4-year follow-up.

BACKGROUND: The purpose of this study is to report on cost, outcomes, reliability, and safety of reverse shoulder arthroplasty (RSA) in patients with symptomatic advanced rotator cuff deficiency. METHODS: Fifty-five primary RSA patients operated on at a single institution by a single surgeon were prospectively studied for a mean of 48 months (range, 31-71 months). For each patient, validated subjective and independently evaluated objective outcome data were collected to determine clinical reliability. In addition, safety, defined as major complications, as well as direct costs specific to each patient, were collected and analyzed. RESULTS: There were significant improvements (P < .05) in all clinical measures with the exception of the general health and vitality components as well as the mental component summary scores of the Short Form 36 version 2 (SF-36v2). In addition, the majority of the patients met the criteria set forth for clinical reliability (53 of 55 [96%]) and safety (49 of 55 [89%]). The mean total 4-year cost was $24,661, with the hospitalization accounting for 92% of this cost. Fiscal year was found to be responsible for the greatest fluctuation in total cost (P < .001). In addition, a lower comorbidity burden (P < .001), a higher preoperative extremity impairment rating (P < .001), higher postoperative role-emotional component scores on the SF-36v2 (P = .001), and lower postoperative social functioning component scores on the SF-36v2 (P = .005) were correlated with less cost. CONCLUSION: The mean 4-year total cost of $24,661 allowed the purchase of treatment with RSA, leading to a greater than 5-fold reduction in pain and a 70% improvement in shoulder function with a small risk of harm.

Scapular fractures after reverse shoulder arthroplasty: evaluation of risk factors and the reliability of a proposed classification.

BACKGROUND: The aims were to determine the sensitivity of plain radiographs to detect scapular fractures after reverse shoulder arthroplasty (RSA), to test the reliability of a proposed classification, and to evaluate risk factors. MATERIALS AND METHODS: We matched 53 patients with scapular fractures after RSA to 212 control patients. Clinical risk factors were assessed by correlating comorbidities. Independent observers reviewed radiographs to assess fracture detection accuracy and test the reliability of a proposed classification. Radiographic risks were evaluated by measuring acromial thickness, acromial tilt, glenoid-to-tuberosity distance, and acromion-to-tuberosity (AT) distance. RESULTS: Independent reviewers accurately diagnosed 78.8% of fractures and 97.4% of controls with good inter-rater reliability (κ = 0.782) and excellent intrarater reliability (κ = 0.862). Inter-rater reliability of the classification was moderate (κ = 0.422). Osteoporosis significantly increased the risk of fracture (odds ratio, 1.97; 95% confidence interval, 1.00-3.91); however, no difference was found for other comorbidities or between preoperative and postoperative radiographic parameters. A significant difference occurred between groups from the postoperative radiographs to the most recent radiographs for AT distance (0.4 ± 5.5 mm for control group and 8.3 ± 7.6 mm for fracture group, P < .001) and acromial tilt (1.8° ± 6.3° for control group and 14° ± 15° for fracture group, P < .001). Of 16 scapular spine fractures, 14 occurred from a screw tip; however, screw orientation and length were not different between groups. CONCLUSION: Osteoporosis is a significant risk factor for scapular fractures after RSA. The current classification has only moderate reliability, suggesting that an alternative classification method is needed. Decreasing AT distance and increasing acromial tilt on consecutive radiographs may improve fracture detection. Advanced imaging may be needed to confirm the diagnosis. Whereas most scapular spine fractures occurred from a screw, the surgical technique did not increase the relative risk.

Large coronal shear fractures of the capitellum and trochlea treated with headless compression screws.

BACKGROUND: The purpose of this study is to retrospectively evaluate the clinical outcomes of 18 patients with large coronal shear fractures of the capitellum and lateral trochlea that underwent open reduction and internal fixation with headless compression screws. METHODS: Eighteen patients were identified (16 women, 2 men) with an average age of 45 years and an average follow-up of 26 months. Fractures were classified according to the Dubberley classification as 11 type-1A injuries and 7 type-2A injuries. RESULTS: All patients, with the exception of 1, had good to excellent functional results by the Broberg-Morrey scale (mean score, 93.3). Average arc of motion was 128 degrees in flexion/extension and 176 degrees in pronation/supination. Radiographically, 3 patients had subsequent development of avascular necrosis and 5 developed arthrosis. No significant negative correlation was noted between the development of avascular necrosis and clinical outcome. Minor complications occurred in 2 patients, but there were no re-operations. CONCLUSION: Headless compression screw fixation allows for stable fixation in patients with large coronal shear fractures of the distal humerus without posterior comminution. LEVEL OF EVIDENCE: 4.

In vitro and finite element analysis of glenoid bone/baseplate interaction in the reverse shoulder design.

We developed biomechanical and finite element models, using high-strength polyurethane foam blocks, to represent the glenoid bone/baseplate junction to determine if increasing the distance between the glenoid bone and the center of rotation of the glenosphere increases baseplate motion during static loading in the reverse shoulder design. Although there was a general trend toward increased baseplate motion with increasing distance from the glenoid to the center of rotation, in vitro mechanical testing revealed no significant difference between the 7 glenosphere types tested, with average baseplate motion during 1000 load cycles ranging from 90 mum to 120 mum. Results from the finite element analysis strongly correlated with the in vitro mechanical testing. The magnitude of baseplate motion occurring in a modeled representation of bone under simulated physiologic loading conditions was similar for the 7 reverse shoulder glenoid components tested in this study.

Young patients with shoulder chondrolysis following arthroscopic shoulder surgery treated with total shoulder arthroplasty.

Chondrolysis following shoulder arthroscopy is a devastating complication, often seen in young patients. After nonoperative measures have been exhausted, there are few treatment options available that reliably improve pain and function. The purpose of this study is to examine the intra-operative findings, radiographic features, and clinical outcomes of a series of patients with chondrolysis following arthroscopic surgery managed with a total shoulder arthroplasty. A retrospective review was performed on 11 patients (average age 39) with shoulder chondrolysis following arthroscopy. Attention was focused on review of the index arthroscopy, radiographs, and functional outcome scores prior to total shoulder arthroplasty, as well as intra-operative cultures, histology, radiographs, and functional outcomes from most recent follow-up. All patients were treated with total shoulder arthroplasty at an average of 26 months after the index arthroscopy. Preoperative and postoperative radiographs were reviewed, and outcomes were compared using validated measurements. Statistically significant improvements in shoulder abduction (89 degrees -123 degrees , P = .027), external rotation (26 degrees -48 degrees , P = .037), total ASES scores (30-77.5, P = .0039), and SST scores (3-8, P = .0078) were noted. Ten patients subjectively rated their outcomes as good or excellent, with 1 as satisfactory. Chondrolysis after shoulder arthroscopy has a rapid clinical progression and is likely multifactorial in etiology. Early results of total shoulder arthroplasty show an opportunity for improvements in pain and function; however, progressive glenoid radiolucencies may develop in these patients.

Outcomes and Costs of Reverse Shoulder Arthroplasty in the Morbidly Obese: A Case Control Study.

BACKGROUND: The rising number of morbidly obese patients has important consequences for the health-care system. We investigated the effect of morbid obesity on outcomes, complications, discharge disposition, and costs in patients undergoing reverse shoulder arthroplasty. METHODS: Our joint registry was searched for all patients who had undergone primary reverse shoulder arthroplasty for a reason other than fracture from 2003 to 2010 and had a minimum of twenty-four months of follow-up. Twenty-one patients with a body mass index (BMI) of ≥40 kg/m2 were identified (follow-up, 45 ± 16 months; sex, seventeen female and four male; age, 69 ± 7 years) and were compared with sixty-three matched control patients with a BMI of <30 kg/m2 (follow-up, 48 ± 20 months; sex, fifty female and thirteen male; age, 71 ± 6 years) after an a priori sample size calculation. Outcome instrument data were obtained preoperatively and postoperatively. The Charlson-Deyo comorbidity index (CDI) score, total comorbidities, operative time, blood loss, duration of hospital stay, discharge disposition, costs, and complications were recorded. RESULTS: Compared with nonobese patients, morbidly obese patients had similar improvements in functional outcomes (e.g., American Shoulder and Elbow Surgeons score, 32 to 69 compared with 40 to 78) and in shoulder motion (e.g., forward flexion, 61° to 140° compared with 74° to 153°); all improvements were significant (p < 0.05). Morbidly obese patients had a similar rate of scapular notching (odds ratio [OR] = 0.58, p = 0.63), more total comorbidities excluding obesity (six compared with four, p = 0.001), a higher CDI (2 compared with 1, p = 0.025), and a higher rate of obstructive sleep apnea (OR = 27.7, p = 0.0001). Their operative time was thirteen minutes longer (p = 0.014) and their blood loss was 40 mL greater (p = 0.008). Morbidly obese patients had a similar duration of stay (3.1 compared with 2.6 days, p = 0.823) and hospital readmission rate (OR = 16.3, p = 0.08) but a sixfold higher rate of discharge to rehabilitation facilities rather than to home (OR = 8, p < 0.0001). Hospital costs were higher by $2974 (p = 0.009). The rates of major complications (n = 4 compared with 8, p = 0.479) and of minor complications (n = 3 compared with 14, p = 0.440) were similar. No intraoperative complications or mechanical device failures were noted in either group. CONCLUSIONS: Reverse shoulder arthroplasty appears to be as safe and effective in morbidly obese patients, although it has an increased cost and patients have a lower rate of discharge to home and greater care needs after discharge. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Cost analysis in shoulder arthroplasty surgery.

Cost in shoulder surgery has taken on a new focus with passage of the Patient Protection and Affordable Care Act. As part of this law, there is a provision for Accountable Care Organizations (ACOs) and the bundled payment initiative. In this model, one entity would receive a single payment for an episode of care and distribute funds to all other parties involved. Given its reproducible nature, shoulder arthroplasty is ideally situated to become a model for an episode of care. Currently, there is little research into cost in shoulder arthroplasty surgery. The current analyses do not provide surgeons with a method for determining the cost and outcomes of their interventions, which is necessary to the success of bundled payment. Surgeons are ideally positioned to become leaders in ACOs, but in order for them to do so a methodology must be developed where accurate costs and outcomes can be determined for the episode of care.