Humeral stem loosening is not always prosthetic joint infection.

BACKGROUND: Aseptic humeral stem loosening is an uncommon complication of shoulder arthroplasty, and its presence has been considered a highly specific predictor of prosthetic joint infection (PJI). Literature on aseptic humeral stem loosening is sparse. The primary purpose of this study was to determine the rate of aseptic humeral loosening in revision shoulder arthroplasty. Secondarily, we sought to identify predictors of septic and aseptic humeral loosening. METHODS: Our institutional revision shoulder arthroplasty database was reviewed. Inclusion criteria were patients with humeral stem loosening as indicated in the operative report. Patient demographics, index surgery and indication, revision surgery and indication, and operative data were recorded. Charts were manually reviewed, and PJI scores were calculated using the International Consensus Meeting scoring criteria. International Consensus Meeting classifications of PJI "unlikely" and "possible" were considered aseptic, and PJI "probable" and "definite" were considered septic. Statistical analysis was performed to determine associations between the abovementioned variables and aseptic humeral loosening. RESULTS: Forty-six patients with 48 shoulders were included in our analysis. Ten cases (21%) were classified as definite PJI, 13 cases (27%) were classified as probable PJI, 4 cases (8%) were classified as possible PJI, and 21 cases (44%) were classified as PJI unlikely. On analysis of stem design, there were no statistically significant associations with aseptic loosening; although, a lack of proximal porous ingrowth surface trended toward higher rates of aseptic loosening in all patients and in anatomic total shoulder arthroplasty (ATSA) and reverse total shoulder arthroplasty (RTSA) subgroup analyses. In the index RTSA subgroup, aseptic loosening was associated with female sex (P = .005). Seventeen of 39 shoulders (44%) that underwent either index ATSA or RTSA demonstrated concomitant glenoid loosening. The absence of glenoid loosening was associated with aseptic humeral loosening in index ATSA and RTSA (P < .001). CONCLUSION: Fifty-two % of revision shoulder arthroplasty cases with humeral loosening performed at our institution were aseptic. There appear to be distinct demographic and radiographic factors that are more commonly associated with aseptic as opposed to septic humeral loosening. Our data demonstrate that demographic predictors of aseptic loosening of RTSA include female sex. The absence of glenoid component loosening is associated with aseptic humeral loosening and concomitant glenoid loosening is associated with septic humeral loosening. Understanding of these factors can guide the preoperative index of suspicion for PJI in the setting of humeral stem loosening.

Patients With Mild Osteoarthritis Are Less Likely to Achieve a Clinically Important Improvement in Pain or Function After Anatomic Total Shoulder Arthroplasty.

BACKGROUND: The severity of glenohumeral osteoarthritis (OA) as demonstrated by preoperative radiographs and patient-reported pain plays an important role in the indication for anatomic total shoulder arthroplasty (aTSA). In hip and knee research, data about the effect of the severity of preoperative radiographic OA on the outcome of total joint arthroplasty have been mixed. For shoulder replacement, we are unsure of the effects of radiographic severity on outcomes. QUESTIONS/PURPOSES: This study investigated whether the preoperative radiographic severity of glenohumeral OA is associated with improvement in pain and function after aTSA. We asked, (1) does the severity of glenohumeral OA correlate with improvement in patient-reported outcomes after TSA (delta American Shoulder and Elbow Surgeons score [postoperative-preoperative], delta Single Assessment Numeric Evaluation, delta Simple Shoulder Test, and delta VAS)? (2) Is having mild osteoarthritis associated with not meeting the minimum clinically important differences in preoperative and postoperative American Shoulder and Elbow Surgeons scores? METHODS: An institutional query of patients who underwent aTSA for OA was performed between January 2015 and December 2018. A total of 1035 patients were eligible; however, only patients with adequate preoperative radiographs and patient-reported outcome measures collected preoperatively and at a minimum of 2 years postoperatively were included. Patients with proximal humerus fractures, inflammatory arthropathy, cuff tear arthropathy, prior ipsilateral rotator cuff repair, brachial plexus injury or neuromuscular disorder, workers compensation, periprosthetic joint infection, or revision surgery within 2 years were excluded. Patient characteristics, comorbidities, and prior shoulder surgery were recorded. The severity of OA was classified based on the modified Samilson-Prieto and Walch classification. The association between Samilson-Prieto grade and patient-reported outcome measures (American Shoulder and Elbow Surgeons Score, Single Assessment Numeric Evaluation, Simple Shoulder Test, and VAS score) was evaluated. Radiographic characteristics, patient demographics, comorbidities, and prior surgery were also evaluated for the potential risk of not achieving improvement in the minimum clinically important difference (16.1) with respect to the American Shoulder and Elbow Surgeons score. The American Shoulder and Elbow Surgeons score is scored 0 to 100, with higher scores representing less pain and better function. A total of 206 patients (20% of those eligible) with a mean follow-up of 2.3 years were included. Twenty-three patients had Samilson-Prieto Grade I, 38 had Grade II, 57 had Grade III, and 88 had Grade IV. RESULTS: There were no differences in improvements (delta) between the groups and between patient-reported outcome scores (American Shoulder and Elbow Surgeons score, Single Assessment Numeric Evaluation, Simple Shoulder Test, and VAS). Compared with patients with more severe osteoarthritis (Samilson-Prieto Grades II, III, and IV), a higher proportion of patients with less severe osteoarthritis (Grade I) did not exceed the minimum clinical important difference for the American Shoulder and Elbow Surgeons score (22% [five of 23] versus 4% [seven of 183]; odds ratio 0.14 [95% confidence interval 0.04 to 0.520]; p = 0.006). CONCLUSION: The improvement in patient-reported outcome measure scores was similar regardless of radiographic severity after aTSA. Surgeons should use caution when recommending surgery to patients with less severe OA because a higher percentage did not improve, based on the minimum clinically important difference. LEVEL OF EVIDENCE: Level III, therapeutic study.

Management of proximal humerus bone loss with allograft prosthetic composite technique in shoulder arthroplasty.

BACKGROUND: Proximal humerus bone loss in shoulder arthroplasty is a difficult problem with limited treatment options. It most commonly occurs in the setting of a previously failed shoulder arthroplasty; however, it is occasionally encountered in cases of primary shoulder arthroplasty. Reconstruction of the proximal humerus is essential for soft tissue tension for implant stability and maximizing function. The purpose of this study was to analyze the clinical and functional outcomes of the allograft prosthetic composite (APC) technique for the management of proximal humeral bone loss in shoulder arthroplasty. METHODS: A retrospective review was performed of all patients who underwent primary or revision shoulder arthroplasty using an APC technique with a reverse shoulder arthroplasty prosthesis for the management of proximal humerus bone loss. Data collected included demographic variables, previous shoulder surgeries, indication for APC, type of allograft utilized, fixation technique, and reoperation and revision rates. Patients were contacted by phone and/or email survey to obtain the latest patient-reported functional outcome scores. RESULTS: We identified 14 patients who underwent shoulder arthroplasty using the APC technique with a reverse shoulder arthroplasty prosthesis. One (7.1%) was performed as a primary arthroplasty, and 13 (92.9%) were performed as revision arthroplasties. The indications for APC were instability (21.4%), periprosthetic fracture (21.4%), periprosthetic joint infection (14.3%), humeral component loosening (14.3%), rotator cuff failure (14.3%), fracture sequelae (7.1%), and failed hemiarthroplasty (7.1%). In terms of allograft type, 10 (71.4%) were performed with proximal femur allograft and 4 (28.6%) with proximal humerus allograft. There were 6 patients (42.9%) who sustained postoperative complications, 5 patients (35.7%) had instability, and 1 (7.1%) patient had postoperative wound drainage. All patients with a complication required a revision arthroplasty. CONCLUSION: The APC technique used to address proximal humerus bone loss in shoulder arthroplasty has a high complication rate with fair patient-reported functional outcome scores. Most of the postoperative complications and reoperations are related to implant instability.

Complications after operative treatment of high-grade acromioclavicular injuries.

BACKGROUND: Treatment of Rockwood type III-V acromioclavicular (AC) joint injuries remains controversial. Numerous reconstruction techniques have been proposed. The purpose of this study was to describe the complication profile in a large cohort of patients who underwent surgical management of AC joint separations using a variety of reconstruction strategies. METHODS: All patients who underwent surgery for AC joint injuries from 2013 to 2019 at a single institution were identified. Chart review was performed to capture patient demographics, radiographic measurements, operative techniques, postoperative complications, and revision surgery. Structural failure was defined as a radiographic loss of reduction of greater than 50% when comparing immediate and final postoperative imaging. Logistic regression analysis was performed to identify risk factors for complications and revision surgery. RESULTS: Of the 279 patients included in the study, 66 (24%) had type III separations, 20 (7%) type IV, and 193 (69%) type V. Fifty-three percent underwent surgery acutely (<6 weeks of injury), and 40% were chronic (>3 months). A total of 252 of the 279 surgeries (90%) were performed open and 27 (10%) were arthroscopically assisted. Allograft was used in 164 of 279 (59%) cases. Specific operative techniques (with or without allograft) included hook plating (1%), modified Weaver Dunn (16%), cortical button fixation (18%), and suture fixation (65%). At mean 28-week follow-up, 108 complications were identified in 97 patients (35%). Complications were identified at mean 20 ± 21 weeks. Sixty-nine structural failures (25%) were identified. Persistent AC joint pain requiring injection, clavicle fracture, adhesive capsulitis, and hardware complications were the other most common complications. Twenty-one patients (8%) underwent unplanned revision surgery at mean 38 ± 28 weeks after the index procedure, with the most common indication for structural failure, hardware complications, or fracture of the clavicle or coracoid. Patients who had surgery after 6 weeks from injury had a significantly greater risk of having a complication (odds ratio [OR] 3.19, 95% confidence interval [CI] 1.34-7.77, P = .009) and a significantly greater risk of having structural failure (OR 2.65, 95% CI 1.38-5.28, P = .004). Patients who had an arthroscopic technique had a greater risk of structural failure (P = .002). Complications, structural failure, and revision surgery were not significantly correlated with use of allograft or specific operative techniques. CONCLUSION: Surgical management of AC joint injuries is associated with a relatively high complication profile. Loss of reduction in the postoperative period is common. However, the revision surgery rate is low. These findings are important for patient preoperative counseling.

Anatomic shoulder arthroplasty in Walch type C glenoid deformity: mid- to long-term outcomes.

BACKGROUND: Hypoplastic glenoid morphology in the setting of glenohumeral osteoarthritis is a rare yet complex surgical problem. Treatment of this patient population with anatomic total shoulder arthroplasty (aTSA) remains controversial. Furthermore, there is no gold-standard approach, with limited guidance for surgeons on the need for glenoid version correction in the setting of a dysplastic glenoid. The purpose of this study was to evaluate mid- to long-term outcomes and reoperation rates of aTSA for the treatment of primary glenohumeral osteoarthritis with Walch type C glenoid deformity. METHODS: This observational, retrospective cohort study identified patients with a Walch type C glenoid who underwent aTSA at 2 institutions between 2007 and 2016. Patients were contacted to complete updated patient-reported outcome measures at a minimum of 5.5 years postoperatively. The outcome measures collected included the American Shoulder and Elbow Surgeons (ASES) score and Single Assessment Numeric Evaluation (SANE) score. Secondary outcomes included any additional surgical procedures on the operative shoulder, patient satisfaction, and willingness to undergo aTSA again. RESULTS: In total, 30 patients met the inclusion criteria, of whom 26 (86.7%) were able to be contacted to undergo final outcome evaluations. The mean age at the time of surgery was 61.3 years (range, 40.9-75.5 years), and 20 patients (76.9%) were men. The mean follow-up period was 8.5 years (range, 5.5-11.3 years) after surgery. Treatment was performed with an augmented component in 9 patients and with a standard component in 17. Of the 17 patients with non-augmented components, 9 underwent partial correction with asymmetrical reaming, 3 received a mini-inset glenoid component, and 2 had an anteriorly offset humeral component. At final follow-up, patients had a mean ASES score of 83.6 ± 16.7, ASES pain score of 24.7 ± 20.8, SANE score of 80.4 ± 20.9, and patient satisfaction rate of 84.1%. No statistically significant differences in any outcome measure were observed between patients with augmented glenoid components and those with non-augmented glenoid components. One revision to reverse shoulder arthroplasty was performed for instability at 7 years postoperatively after a traumatic dislocation. All patients reported that they would be willing to undergo the same surgical procedure again. DISCUSSION: Despite variance in glenoid reconstructive approach, aTSA provides satisfactory and sustained improvements in patient-reported outcomes in patients with glenoid dysplasia and primary glenohumeral osteoarthritis with a low revision rate at a mean of 8.5 years. Anatomic shoulder arthroplasty should remain a surgical option in patients with Walch type C glenoid deformity.

Factors associated with functional improvement after posteriorly augmented total shoulder arthroplasty.

BACKGROUND: Posteriorly augmented glenoid components in anatomic total shoulder arthroplasty (TSA) address posterior glenoid bone loss with inconsistent results. The purpose of this study was to identify preoperative and postoperative factors that impact range of motion (ROM) and function after augmented TSA in patients with type B2 or B3 glenoid morphology. METHODS: This was a retrospective review of all patients who underwent TSA with a step-type augmentation performed by a single surgeon between 2009 and 2018. Patients with Walch type B2 or B3 glenoids were included. Outcomes included forward elevation (FE), external rotation (ER), internal rotation (IR), Single Assessment Numeric Evaluation (SANE) score, and visual analog scale pain score. Preoperative imaging was reviewed to assess glenoid retroversion and posterior humeral head subluxation relative to the scapular body and midglenoid face. Postoperative measurements included glenoid retroversion, subluxation relative to the scapular body, subluxation relative to the central glenoid peg, and center-peg osteolysis. Measurements were performed by investigators blinded to ROM and functional outcome scores. RESULTS: Fifty patients (mean age, 68.1 ± 8.0 years) with a mean follow-up period of 42.0 months (range, 24-106 months) were included. Glenoid morphology included type B2 glenoids in 41 patients and type B3 glenoids in 9. One patient had center-peg osteolysis, and 1 patient had glenoid component loosening. Average preoperative FE, ER, and IR were 110°, 21°, and S1, respectively. Average postoperative FE, ER, and IR were 155°, 42°, and L1, respectively. The mean postoperative visual analog scale score was 0.5 ± 0.8, and the mean SANE score was 94.5 ± 5.6. Type B3 glenoids were associated with better postoperative IR compared with type B2 glenoids (T10 vs. L1, P = .024), with no other differences in ROM between the glenoid types. Preoperative glenoid retroversion did not significantly impact postoperative ROM. Postoperative glenoid component retroversion and residual posterior subluxation relative to the scapular body or glenoid face did not correlate with ROM in any plane. However, posterior subluxation relative to the glenoid face was moderately associated with lower SANE scores (r = -0.448, P = .006). CONCLUSION: Patients achieved excellent functional outcomes and pain improvement after TSA with an augmented glenoid component. Postoperative ROM and function showed no clinically important associations with preoperative or postoperative glenoid retroversion or humeral head subluxation in our cohort of posteriorly augmented TSAs, except for worse functional scores with increased humeral head subluxation in relation to the glenoid surface.

Outcomes of instability after reverse shoulder arthroplasty: reoperation and persistent instability are common.

HYPOTHESIS: Although risk factors for instability after reverse shoulder arthroplasty (RSA) have been extensively studied, the outcomes of patients who experience instability are unknown. The purpose of this study was to evaluate functional outcomes in patients with instability after RSA. METHODS: We retrospectively identified patients with instability after RSA with a minimum of 2 years' follow-up from an institutional database. Baseline data were recorded, and all patients we contacted to obtain clinical outcome scores. Patients who required revision surgery and those treated successfully with closed reduction were compared. RESULTS: Fifty patients were included. Of these patients, 40 (80%) required revision surgery whereas 10 (20%) were treated successfully with closed reduction. At an average follow-up of 63.7 months (range, 24-123 months), outcome scores did not differ between groups. Patients who required revision surgery were more likely to have undergone previous shoulder surgery, prior to their index arthroplasty (P = .031). Seventeen patients (42.5%) reported recurrent instability following revision surgery, and 14 (35.0%) required additional revision surgery. Ultimately, stability was never achieved in 7 of 50 patients (14%) after their index instability event. CONCLUSION: Although instability after RSA can commonly be corrected with reasonable functional results, multiple procedures may be needed and some patients may experience persistent instability.

Total shoulder arthroplasty using an inlay glenoid component for glenoid deficiency: mid- to long-term follow-up of a previously published cohort.

BACKGROUND: The short-term results of total shoulder arthroplasty with an inlay glenoid component performed by a single surgeon in patients with glenoid bone loss have previously been reported. The purpose of this study was to investigate the mid- to long-term clinical and radiographic outcomes of these patients. METHODS: We identified a cohort of patients who underwent total shoulder arthroplasty with an inlay glenoid component performed by a single surgeon between 2010 and 2019 for severe glenoid dysplasia and/or glenoid bone loss. Patients with a minimum of 2 years' follow-up were evaluated regarding preoperative and postoperative range of motion, radiographic findings, visual analog scale pain scores, and Single Assessment Numeric Evaluation scores. RESULTS: Overall, 39 shoulders in 33 patients were treated with an inlay glenoid component for severe glenoid bone loss. Four patients were lost to follow-up, and 1 patient died with a well-functioning implant in place. The final cohort included 34 shoulders in 28 patients (46.4% female patients [13 of 28] and 53.6% male patients [15 of 28]) with a mean age of 66.9 years (range, 58-81 years) and mean follow-up period of 68.3 months. Of the 34 cases, 5 were revision cases. One patient died following 2-year follow-up. Of the shoulders, 10 were classified as Walch type A2, 4 were classified as Walch type B3, and 15 were classified as Walch type C; 5 shoulders were unable to be classified. We observed statistically significant increases in range of motion (forward elevation, 38.1° [P < .001]; external rotation, 18.8° [P < .001]) and improvement in the Single Assessment Numeric Evaluation score (from 26.6 to 81.0, P < .001). Two patients underwent conversion to reverse shoulder arthroplasty at 2.2 and 1.7 years postoperatively. CONCLUSION: Inlay glenoid components provide a low rate of revision and improved clinical and functional outcomes at mid- to long-term follow-up.

Mid- to long-term outcomes of augmented and nonaugmented anatomic shoulder arthroplasty in Walch B3 glenoids.

BACKGROUND: In cases of severe osteoarthritis, posterior glenoid wear leads to acquired retroversion of the glenoid. Surgical treatment of glenoids with acquired retroversion and posterior humeral subluxation with anatomic total shoulder arthroplasty (aTSA) is controversial. The purpose of this study was to determine mid- to long-term outcomes and reoperation rates of augmented and nonaugmented aTSA for treatment of glenohumeral osteoarthritis with Walch B3 glenoid deformity. METHODS: This observational cohort study reviewed patients with a Walch B3 glenoid undergoing aTSA at a single institution between 2007 and 2014. Patients were contacted to complete updated patient-reported outcome measures at a minimum of 6 years postoperatively. Outcome measures collected included the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) score and Single Alpha Numeric Evaluation (SANE) score. Secondary outcomes included any additional surgery on the operative shoulder, patient satisfaction, and willingness to undergo aTSA again. RESULTS: Thirty-nine patients met inclusion criteria, and thirty-five (89.7%) were able to be contacted for final outcomes evaluation. Mean follow-up was 8.7 years (range 6-13) after surgery. Sixteen patients were treated with an augmented glenoid component, and 19 patients were treated with a standard glenoid component. Of those with standard components, all were partially corrected with asymmetric reaming. At final follow-up, there were no statistically significant differences between those with augmented and standard glenoid components for mean ASES score (93.3 vs. 85.7, P = .217), ASES pain score (47.2 vs. 41.6, P = .161), SANE score (87.8 vs. 86.0, P = .692), and percentage patient satisfaction (95.6% vs. 96.8%, P = .735), forward elevation (148° vs. 149°, P = .852), or external rotation (36° vs. 39°, P = .202). No patient in either group had undergone revision surgery of the operative shoulder over the study period and all patients stated that they would undergo the same surgery again. DISCUSSION: Both augmented and standard aTSA can provide satisfactory and sustained improvements in patient-reported outcomes in patients with acquired glenoid retroversion due to glenohumeral osteoarthritis. Despite a trend toward alternative treatment options, anatomic shoulder arthroplasty should remain a surgical consideration even in the setting of a Walch B3 glenoid deformity.

The Basic Shoulder Arthroplasty: Simple Shoulder Replacement for the Generalist.

Shoulder arthroplasty was first introduced through the developments of Dr. Charles Neer and over the past decade has seen several advancements. Improved recognition and training have heightened the awareness of arthroplasty as a treatment alternative both for surgeons and patients. The addition of reverse shoulder arthroplasty has been the driving force behind the explosive growth of arthroplasty and is now performed more often than anatomic shoulder arthroplasty. Although revision shoulder arthroplasty is primarily of interest to the subspecialist, it is a skill sought by the general orthopaedic surgeon. It is important for the orthopaedic surgeon to be knowledgeable about the planning, necessary skills, and management of basic shoulder arthroplasty.

Early clinical and radiographic outcomes of an augmented baseplate in reverse shoulder arthroplasty for glenohumeral arthritis with glenoid deformity.

BACKGROUND: Glenoid deformity is commonly encountered in patients undergoing reverse shoulder arthroplasty (RSA). Augmented baseplates can correct glenoid deformity while potentially avoiding certain complications encountered with structural bone graft. Limited evidence exists to support the use of metallic augmented baseplates in RSA. METHODS: We performed a retrospective review to identify all patients treated with an augmented baseplate during primary RSA with a minimum of 1 year of clinical and radiographic follow-up. Preoperative radiographs and advanced imaging were used to determine glenoid morphology and deformity. Postoperative radiographs were used to evaluate for deformity correction, radiographic complications, and early baseplate loosening or failure. Prospectively collected clinical data and patient-reported outcome scores were determined. RESULTS: Primary RSA was performed with an augmented baseplate in 44 patients (mean age, 72 ± 6 years; 15 half-wedge and 29 full-wedge augmentations). Glenoid retroversion was significantly improved for the entire cohort (P = .001). Among the 22 patients with either Walch type B2, B3, or C glenoid morphology, glenoid version improved from 28° ± 8° to 16° ± 8° (P = .001). Glenoid inclination, as determined by the ß angle, was significantly improved for the entire cohort (P < .001). Among the 18 patients with Favard type E2 or E3 glenoid morphology, glenoid inclination improved from 67° ± 7° to 81° ± 8° (P < .001). Postoperative range of motion and functional outcome scores including the American Shoulder and Elbow Surgeons score, Simple Shoulder Test score, Single Assessment Numeric Evaluation score, and visual analog scale score for pain significantly improved within the entire cohort (P < .05). No patients had evidence of baseplate loosening or failure of the glenoid component. Acromial stress fractures developed in 5 patients (11.4%), and 2 patients (4.5%) underwent a reoperation unrelated to the glenoid component. DISCUSSION AND CONCLUSION: Primary RSA with an augmented baseplate results in excellent short-term clinical outcomes and significant deformity correction in patients with advanced glenoid deformity. There were no complications related to the augmented baseplate or glenoid component. The rate of acromial stress fractures appears higher than typically reported and warrants further investigation.

Spacers for life: high mortality rate associated with definitive treatment of shoulder periprosthetic infection with permanent antibiotic spacer.

BACKGROUND: Periprosthetic joint infection following shoulder arthroplasty represents a challenging problem for orthopedic surgeons. Although recent studies have supported 2-stage exchanges, this treatment choice may not be appropriate for all patients. Definitive antibiotic spacer placement represents one treatment strategy with limited reported outcomes in the literature. The purpose of this study was to investigate the mortality rate and functional outcomes associated with definitive spacer placement. METHODS: A retrospective chart review identified 17 patients who were treated with definitive antibiotic spacer placement (18 spacers) and were followed up for a minimum of 2 years after surgery. The mortality rate over the study period was determined. Demographic information, clinical course, patient-reported outcomes (American Shoulder and Elbow Surgeons score, Single Assessment Numeric Evaluation score, and Veterans RAND 12 [VR-12] score), infection parameters as defined by International Consensus Meeting criteria, radiographic evaluation findings, and rotator cuff integrity at the time of spacer placement were collected. RESULTS: Seventeen patients underwent treatment with retained antibiotic spacers at a mean age of 62.4 years (range, 50-73 years). Ten patients were women, and the mean body mass index was 30.5 (range, 22.9-39.9). Spacer placement occurred at a mean of 6.1 years (range, 0.48-14.9 years) following index arthroplasty. Five patients required spacer exchange. The most common organisms were Cutibacterium acnes (6) and methicillin-sensitive Staphylococcus aureus (6); in addition, methicillin-resistant S aureus (2), coagulase-negative Staphylococcus (2), Serratia marcescens (1), gram-positive cocci (1), Enterobacter faecalis (1), Enterobacter cloacae (1), diphtheroids (1), and an infection with negative culture findings (1) were observed. The mortality rate was 52.9% (9 of 17 patients). Among the 8 surviving patients, the mean American Shoulder and Elbow Surgeons score was 33.9 (range, 13.3-80.0), the mean Single Assessment Numeric Evaluation score was 35.6 (range, 0.0-80.0), the mean VR-12 mental score was 57.2 (range, 36.6-66.9), and the mean VR-12 physical score was 37.1 (range, 21.7-64.0) at a mean of 4.7 years (range, 2.0-8.8 years). CONCLUSION: Definitive antibiotic spacer placement is an acceptable method to treat infection in medically frail patients who have a high mortality risk. Spacer exchange may be necessary because of persistent infection, and functional results are poor.

Low-dose aspirin and the rate of symptomatic venous thromboembolic complications following primary shoulder arthroplasty.

BACKGROUND: Venous thromboembolism (VTE) events are infrequent but potentially catastrophic complications following orthopedic surgery. There is currently a paucity of evidence regarding the role of chemoprophylaxis with low-dose aspirin (acetylsalicylic acid [ASA]) after shoulder arthroplasty. METHODS: We conducted a retrospective review of prospectively collected complications occurring within 90 days of 2394 primary shoulder arthroplasties performed over a 3-year period at a single institution. Patients preoperatively underwent risk stratification into medically high risk, moderate risk, or low risk as part of a standardized navigated-care pathway. For chemoprophylaxis, 81 mg of ASA (low dose) was routinely used once daily for 6 weeks unless alternative medications were deemed necessary by the medical team. Baseline demographic information, medical comorbidities, and postoperative VTE prophylaxis, as well as rates of clinically symptomatic VTE, were assessed. RESULTS: Symptomatic VTE occurred after 0.63% of primary shoulder arthroplasties (15 of 2394). There were 9 patients with deep vein thromboses and 6 with pulmonary embolisms. Eighty-one milligrams of ASA was used in 2141 patients (89.4%), resulting in an overall VTE rate of 0.56%. Medically high-risk patients were significantly more likely to have a VTE (P = .018). Patients with a history of deep vein thrombosis, asthma, and cardiac arrhythmia were significantly more likely to have a VTE (P < .05). Complications occurred in 4 patients (0.19%) associated with low-dose ASA and 1 patient (0.63%) associated with a novel oral anticoagulant medication. CONCLUSION: Routine use of low-dose ASA results in a very low risk of VTE and medication-associated complications following primary shoulder arthroplasty. Preoperative medical risk stratification can potentially identify patients at high risk of postoperative VTE.

Radiographic humeral head restoration after total shoulder arthroplasty: does the stem make a difference?

BACKGROUND: Humeral stem designs for total shoulder arthroplasty have varied over the years, with a recent trend toward shorter stems. The purpose of this study was to examine the impact of humeral component stem length on the ability to restore the native humeral head anatomy. METHODS: We performed a retrospective review including patients who underwent total shoulder arthroplasty for primary osteoarthritis between 2007 and 2017 with complete operative reports and adequate radiographs. Surgical data including stem design were collected. Preoperative and postoperative radiographic measurements of the center of rotation (COR), humeral head height (HH), and neck-shaft angle were performed. Restoration of the native humeral anatomy was deemed "acceptable" based on postoperative differences in the COR ≤ 3 mm, HH ≤ 5 mm, and neck-shaft angle > 130°. Deviations between preoperative and postoperative measurements were compared across stem types. All available 2-year stemless implant radiographs were also analyzed. RESULTS: In total, 261 patients were included, with 31 stemless, 43 short-stem, and 187 standard-stem implants. There was no significant difference in COR restoration in the x-axis direction (P = .060) or y-axis direction (P = .579). There was no significant difference in restoration of acceptable HH by stem type (P = .339). Stemless arthroplasty implants were more likely to be placed in varus (22.6%) compared with short-stem (7.0%) and standard-stem (3.7%) designs (P < .001). CONCLUSION: Restoration of humeral anatomic parameters occurred significantly less with stemless implants than with short- and standard-stem implants. The stem of a shoulder arthroplasty implant aids surgeons in accurately restoring patient-specific anatomy.

Three-dimensional measures of posterior bone loss and retroversion in Walch B2 glenoids predict the need for an augmented anatomic glenoid component.

HYPOTHESIS: The purpose of this study is to evaluate whether the amount of measured posterior bone loss on 2- and 3-dimensional (2D and 3D) imaging of Walch B2 glenoids can reliably predict the plan for an augmented anatomic glenoid component. METHODS: Patients with Walch B2 glenoids and preoperative computed tomography (CT) scans were retrospectively identified. 2D axial CT scans were reviewed and posterior bone loss was measured by 3 independent reviewers. Images were then formatted into BluePrint (Wright Medical) preoperative planning software. The same 3 reviewers again measured posterior bone loss on 3D imaging. Additionally, all cases were planned with BluePrint software. An augment was used when the following criteria were unable to be satisfied with standard implants: <10° retroversion, <10° superior inclination, ≥90% backside contact, <2 mm medial reaming, and ≤1 peg perforation. RESULTS: Forty-two patients were included in the final analysis with a mean age of 63.1 ± 6.3 years. As measured by BluePrint, the mean retroversion was 23° ± 7° (range = 9°-40°), the mean superior inclination was 5° ± 6° (range = -9° to 22°), and the mean posterior subluxation was 80% ± 17% (range = 41%-95%). The mean 2D bone loss measurements (3.5 ± 1.6 mm) were significantly lower than the mean 3D bone loss (4.0 ± 1.8 mm) measurements (P = .03). There was substantial agreement between reviewers on both 2D and 3D measurements with an interclass correlation of 0.815 (95% confidence interval [CI] 0.714-0.889, P < .001) and an interclass correlation of 0.802 (95% CI 0.683-0.884, P < .001), respectively. Augments were used in 73.8%, 63.4%, and 63.4% of cases by reviewers 1, 2, and 3, respectively, with moderate agreement with a Fleiss kappa of 0.592 (95% CI 0.416-0.769, P < .001). Augment size was moderately, positively correlated with the amount of bone loss on 3D imaging but not with 2D imaging. After multivariate logistic regression, both 3D bone loss and retroversion were found to be predictive for a plan to use an augment. CONCLUSION: Planning for a posterior augment in Walch B2 glenoids is better predicted with 3D imaging than with 2D imaging, as 2D imaging may underestimate posterior bone loss. Additionally, use of a larger augment size is moderately correlated with posterior bone loss on 3D imaging but not 2D imaging. Standard 2D imaging may be limited in cases of posterior bone loss, and 3D imaging may be beneficial for preoperative planning in Walch B2 glenoids.

Reliability of the modified Walch classification for advanced glenohumeral osteoarthritis using 3-dimensional computed tomography analysis: a study of the ASES B2 Glenoid Multicenter Research Group.

BACKGROUND: Variations in glenoid morphology affect surgical treatment and outcome of advanced glenohumeral osteoarthritis (OA). The purpose of this study was to assess the inter- and intraobserver reliability of the modified Walch classification using 3-dimensional (3D) computed tomography (CT) imaging in a multicenter research group. METHODS: Deidentified preoperative CTs of patients with primary glenohumeral OA undergoing anatomic or reverse total shoulder arthroplasty (TSA) were reviewed with 3D imaging software by 23 experienced shoulder surgeons across 19 institutions. CTs were separated into 2 groups for review: group 1 (96 cases involving all modified Walch classification categories evaluated by 12 readers) and group 2 (98 cases involving posterior glenoid deformity categories [B2, B3, C1, C2] evaluated by 11 readers other than the first 12). Each case group was reviewed by the same set of readers 4 different times (with and without the glenoid vault model present), blindly and in random order. Inter- and intraobserver reliabilities were calculated to assess agreement (slight, fair, moderate, substantial, almost perfect) within groups and by modified Walch classification categories. RESULTS: Interobserver reliability showed fair to moderate agreement for both groups. Group 1 had a kappa of 0.43 (95% confidence interval [CI]: 0.38, 0.48) with the glenoid vault model absent and 0.41 (95% CI: 0.37, 0.46) with it present. Group 2 had a kappa of 0.38 (95% CI: 0.33, 0.43) with the glenoid vault model absent and 0.37 (95% CI: 0.32, 0.43) with it present. Intraobserver reliability showed substantial agreement for group 1 with (0.63, range 0.47-0.71) and without (0.61, range 0.52-0.69) the glenoid vault model present. For group 2, intraobserver reliability showed moderate agreement with the glenoid vault model absent (0.51, range 0.30-0.72), which improved to substantial agreement with the glenoid vault model present (0.61, range 0.34-0.87). DISCUSSION: Inter- and intraobserver reliability of the modified Walch classification were fair to moderate and moderate to substantial, respectively, using standardized 3D CT imaging analysis in a large multicenter study. The findings potentially suggest that cases with a spectrum of posterior glenoid bone loss and/or dysplasia can be harder to distinguish by modified Walch type because of a lack of defined thresholds, and the glenoid vault model may be beneficial in determining Walch type in certain scenarios. The ability to reproducibly separate patients into groups based on preoperative pathology, including Walch type, is important for future studies to accurately evaluate postoperative outcomes in TSA patient cohorts.

Acromial stress fracture following reverse total shoulder arthroplasty: incidence and predictors.

BACKGROUND: Increased use of reverse total shoulder arthroplasty (RTSA) has led to an understanding of unique complications such as acromial stress fractures (ASFs). The factors associated with ASFs are not fully known. This study investigates the incidence and predictors of ASFs following RTSA. METHODS: All RTSAs performed at a single tertiary referral hospital were retrospectively reviewed. ASF findings were classified as a definitive acromial or scapular spine stress fracture based on radiographic findings or stress reaction based on clinical findings (pain and tenderness at the acromion or acromial spine) without radiographic changes. Preoperative and postoperative radiographs were reviewed for radiographic predictors of postoperative acromial stress pathology. Clinical factors and implant characteristics were also investigated. RESULTS: Between September 2010 and January 2017, a total of 1170 RTSAs were performed, with 958 cases (81.9%) having at least 3 months' clinical follow-up (mean, 407 days; range, 90-1698 days). There were 40 ASFs (4.2%) and 61 acromial stress reactions (6.4%). For fractures and reactions, symptom onset averaged 8.8 and 7.3 months (P = .37), respectively, with durations of 4.5 and 2.9 months (P = .02), respectively, following RTSA. Independent predictors of acromial stress pathology were female sex, decreased change in deltoid length, and increased preoperative glenohumeral center-of-rotation medialization. CONCLUSION: Acromion-related symptoms are common following RTSA. Female patients with increased preoperative center-of-rotation medialization had an increased incidence of ASFs. Although this study establishes which patients are at risk of ASFs, methods for prevention of ASFs in these patients remain unclear.

Early radiographic failure of reverse total shoulder arthroplasty with structural bone graft for glenoid bone loss.

INTRODUCTION: Structural glenoid bone grafting in reverse total shoulder arthroplasty (RSA) has previously been reported to have good functional outcomes and low complication rates. We have observed different complication rates and hypothesized that baseplate fixation and severity of deformity may be predictors of early failure. METHODS: We retrospectively identified 44 patients who underwent RSA with structural bone grafting for glenoid bone defects. All patients had preoperative and postoperative (Grashey and axillary) radiographs at a minimum of 1 year after surgery and within 3 months of surgery for evaluation of implant and graft positioning. Clinical data and outcome scores were collected at the same intervals. RESULTS: There were 61% females and 39% males, with an average age of 74 ± 8 years at the time of surgery. The median final radiographic follow-up was 20 months, with 37 primary RSA and 7 revision RSA. Graft resorption was found in 11 of 44 patients (25%), and radiographic failure was found in 11 of 44 patients (25%) at a median of 8 months (range 3-51 months). Forward elevation, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form, Single Assessment Numeric Evaluation (SANE), and Simple Shoulder Test (SST) scores all significantly improved postoperatively (P < .0001). Radiographic baseplate failure was associated with graft resorption (P = .002), more retroversion correction (P = .02), and worse SANE scores at final follow-up (P = .01). DISCUSSION/CONCLUSION: RSA with structural bone graft improved range of motion and function, but there was a larger than previously reported baseplate loosening rate. This early radiographic loosening appeared to be associated with graft resorption, retroversion correction, and worse outcome scores.

Augmented glenoid implants in anatomic total shoulder arthroplasty: review of available implants and current literature.

Glenoid bone loss and retroversion increase the complexity of primary shoulder arthroplasty and affect the outcome. Although eccentric reaming, augmented glenoid implants, bone grafting, and reverse arthroplasty have been used to manage bone loss and retroversion, there is no consensus on treatment. Posteriorly augmented glenoid components can correct retroversion and avoid joint line medialization, which occurs with corrective reaming techniques. Full-wedged, half-wedged, and stepped polyethylene posteriorly augmented designs are currently available for use in the United States. The results of biomechanical and computer model studies support the use of augmented implants for the management of glenoid retroversion of greater than 15°. Currently, most clinical studies are retrospective case series. The short-term results of posteriorly augmented glenoid components are successful, with no clear evidence of the superiority of one design over another and unknown long-term survival rates.

Revision of failed hemiarthroplasty and anatomic total shoulder arthroplasty to reverse total shoulder arthroplasty.

BACKGROUND: The impending burden of revision shoulder arthroplasty has increased interest in outcomes of revision procedures. Revision of failed anatomic arthroplasty to reverse total shoulder arthroplasty has shown promise alongside concerning complication rates. METHODS: Patients who underwent revision shoulder arthroplasty during a 7-year period at a tertiary care health system were identified. Presurgical and operative data were analyzed for 110 patients who met inclusion and exclusion criteria. Patients were contacted at a mean follow-up of 57 ± 26 months (range, 23-113 months) from revision surgery for functional outcomes scores, reoperations, and implant survival. RESULTS: Implant survival was 92% at 2 years and 74% at 5 years. Mean American Shoulder and Elbow Surgeons score, Single Assessment Numerical Evaluation score, and visual analog scale pain scores were 63 ± 24 (range, 5-97), 60 ± 25 (range, 0-100), and 2.9 ± 2.9 (range, 0-10), respectively. Seventy percent of patients were "very satisfied" or "satisfied with their outcome. Complications occurred in 18 patients (20%), and 10 patients (11%) underwent reoperation. CONCLUSIONS: Modest patient results and satisfaction can be achieved with revision of a failed anatomic arthroplasty to a reverse total shoulder arthroplasty. As is typical of revision surgery, complications are common and can compromise results. Further study is needed to identify factors that may contribute to successful outcomes.