Factors affecting risk of recurrence with periprosthetic infection in shoulder arthroplasty.

BACKGROUND: The goal of treating periprosthetic infection, besides its eradication, is to avoid recurrence. The purpose of this study was to evaluate the impact of increasing Infection Severity (IS) score (based on the 2018 International Consensus Meeting on Orthopedic Infections statement), single-stage revision, and pathogenicity of the infective organism on the risk of infection recurrence. METHODS: A database of 790 revisions performed by a single surgeon from 2004-2020 was reviewed for patients with minimum 2-year follow-up and ≥1 positive culture finding and/or pathology result from the revision surgical procedure. In total, 157 cases performed in 144 patients met the inclusion criteria. These cases were then categorized by infection probability (IS score) according to the 2018 consensus statement. Of 157 cases, 46 (29%) were classified as definitely or probably infected; 25 (16%), possibly infected; and 86 (55%), unlikely to be infected. Additionally, patients were grouped by single-stage surgery and pathogenicity of the infective organism. RESULTS: A recurrence in this study was classified as the growth of the same organism in any patient requiring revision surgery. The 86 cases in the group with unlikely infection showed a recurrence rate of 2.3%. The 25 cases in the group with possible infection showed a recurrence rate of 12%. The 46 cases in the group with definite or probable infection showed a recurrence rate of 17.4%. Patients in the definite/probable infection group had a higher rate of recurrence than those in the groups with possible infection and unlikely infection (P = .009). The IS score was higher in the recurrence group than the non-recurrence group (7.5 ± 4.3 vs. 3.9 ± 3.4, P < .001). Overall, patients who underwent 1-stage revision had a 5.0% recurrence rate, but among the 34 patients with an infection classification of definite or probable who underwent 1-stage revision, the recurrence rate was 5.9%. Cases of highly virulent methicillin-resistant Staphylococcus aureus also showed a recurrence rate of 30.8% compared with 4.0% and 5.9% for Cutibacterium acnes and coagulase-negative staphylococci, respectively (P = .005). CONCLUSION: Recurrent infection after treatment of a periprosthetic infection is associated with increasing severity scores, as defined in the 2018 consensus statement, and more aggressive microorganisms. However, a single-stage surgical procedure, even in patients with higher IS scores, did not impart a significantly increased risk of recurrence.

Do preoperative scapular fractures affect long-term outcomes after reverse shoulder arthroplasty?

BACKGROUND: Postoperative scapular stress fractures (SSFs) are a formidable problem after reverse shoulder arthroplasty (RSA). Less is known about patients who have these fractures preoperatively. The primary aim of this study was to examine postoperative satisfaction in patients undergoing primary RSA who have preoperative SSF and compared to a matched cohort without preoperative fracture. The secondary aim was to examine the differences in patient-reported outcomes between and within study cohorts. METHODS: A retrospective chart review of primary RSAs performed by a single surgeon from 2000 to 2020 was conducted. Patients diagnosed with cuff tear arthropathy (CTA), massive cuff tear (MCT), or rheumatoid arthritis (RA) were included. Five hundred twenty-five shoulders met inclusion criteria. Fractures identified on preoperative computed tomography scans were divided into 3 groups: (1) os acromiale, (2) multifragments (MFs), and (3) Levy types. Seventy-two shoulders had an occurrence of SSF. The remaining 453 shoulders were separated into a nonfractured cohort. American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) and visual analog scale (VAS) scores were compared pre- and postoperatively in the total fracture group and the nonfractured group cohort. The multifragment subgroup was also compared to the pooled Os/Levy subgroup. RESULTS: The total incidence of SSF in all shoulders was 13.7%. There was a difference in satisfaction scores at all time points between the nonfracture (7.9 ± 2.8) and total fracture group (5.4 ± 3.6, P < .001, at last visit). There was also a greater ASES total score in the nonfractured group vs the total fracture group at the final visit (69.4 ± 23.4 and 62.1 ± 24.2; P = .02). The MF group had worse ASES functional or VAS functional scores than the Os/Levy group at all time points: at 1 year, ASES function: MF 24.2 ± 14.5 and Os/Levy 30.7 ± 14.2 (P = .045); at 2 years, ASES function: MF 21.4 ± 14.4 and Os/Levy 35.5 ± 10.6 (P < .001); and at last follow-up, VAS function: MF 4.8 ± 2.8 and Os/Levy 6.4 ± 3.2 (P = .023). DISCUSSION: Scapular fractures were proportionally most common in patients diagnosed with CTA (16.3%) compared with a 9.2% and 8.6% incidence in patients diagnosed with MCT and RA, respectively. Patients with preoperative SSF still see an improvement in ASES scores after RSA but do have lower satisfaction scores compared with the nonfractured cohort. The multifragment fracture group has lower functional and satisfaction scores at all postoperative time points compared with both the nonfracture and the Os/Levy fracture group.

Transforaminal lumbar interbody fusion with an expandable interbody device: Two-year clinical and radiographic outcomes.

Background: The use of interbody cages as an adjunct to lumbar spinal fusion remains an important technique to enhance segmental stability, promote solid arthrodesis, maintain neuroforaminal decompression, and preserve/improve segmental lordosis. Appropriate segmental lumbar lordosis and sagittal balance is well-known to be critical for long-term patient outcomes. This study sought to evaluate the radiographic and clinical results of TLIF in patients using an articulating, expandable cage. Primary endpoint was clinical and radiographic outcomes, including complications, at 12 and 24 months. Methods: A total of 37 patients underwent open single-level or 2-level TLIF by a single surgeon using an expandable cage with concomitant bilateral pedicle screws and posterolateral arthrodesis. Clinical outcomes included ODI and VAS for back and legs. Radiographic outcomes included pelvic incidence and tilt, lumbar and segmental lordoses, and disc height at the operative level(s). All outcomes were collected at baseline, 2-weeks, 6-weeks, 3-months, 6-months, 12-months, and 24-months postop. Results: A total of 28 patients were available for analysis. Nine patients failed to follow-up at 24 months. Mean ODI scores showed significant improvement, from pre-to-postoperative at 24 months (55%; p<.0001). VAS for back and legs was significantly lower at 24 months on average by 72 and 79%, respectively (p<.0001 for both). Both segmental and lumbar lordoses significantly improved by 5.3° and 4.2° (p<.0001 and p=.049), respectively. Average disc height improved by 49% or 6.1 mm (p<.001). No device-related complications nor instances of measured subsidence. One patient had a superficial infection, and another had an intraoperatively repaired incidental durotomy. Conclusions: The use of an expandable cage contributed to improvement in both segmental and lumbar lordosis with no reported complications at 24-month follow-up. All clinical measures significantly improved as well. The expandable cage design represents an effective and safe option to increase cage size and allow significant segmental lordosis correction.

Humeral loosening in reverse shoulder arthroplasty: an analysis of 2,342 cases.

INTRODUCTION: Humeral loosening is a rare complication in reverse shoulder arthroplasty (RSA) representing approximately 1% of total complications. The purpose of this study is to identify patients who underwent RSA and were revised because of loosening of the humeral component, identify patients who are at increased risk, and report on their surgical outcomes. MATERIALS AND METHODS: A retrospective review of all patients who received a primary RSA or revision RSA (rRSA) by a single surgeon from 2002-2021 identified a total of 1591 primary RSA and 751 rRSA procedures. These procedures were then organized based on indication for surgery. Further analysis was performed to identify RSAs that were subsequently revised because of aseptic loosening of the humeral component. A total of 41 surgeries met the inclusion criterion for the study, which was any RSA or rRSA that was revised because of loosening of the humeral component. Exclusion criterion was revision for a reason other than humeral loosening, neurogenic arthritis, or revision for loosening that was not originally implanted by the senior author (9 surgeries). Ultimately, 32 surgeries met criteria for further analysis. These 32 surgeries were organized by indication for preceding RSA or rRSA and were assessed for an association between indication for RSA or rRSA and eventual revision for humeral loosening. Additionally, these procedures were compared to a "control cohort" of procedures that were not revised and that had minimum 2 years' follow-up. To assess outcomes for these patients, pre- and postoperative Simple Shoulder Test, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), and ranges of motion were compared. Twenty procedures had sufficient data for outcomes analysis and were followed for an average of 54 months (range: 24-132 months). RESULTS: In primary RSAs, procedures performed for fracture or fracture sequelae were associated with revision for humeral-sided loosening (P = .009). In rRSAs, procedures performed for failed hemiarthroplasty for CTA were associated with rerevision for humeral-sided loosening (P = .009). Nine percent of patients revised for humeral loosening required rerevision for recurrent humeral loosening. Analysis of patients with 2-year clinical follow-up for humeral-sided loosening showed improvement in ASES pain (P = .014), ASES function (P = .042), and total ASES scores (P = .007). CONCLUSION: Humeral loosening is rare in RSA. In our cohort, 0.7% of the primary RSAs performed and 2.8% of the rRSAs performed were eventually revised for humeral loosening. Revisions of RSA for humeral loosening yield modest clinical improvements. Rerevision for humeral loosening was 6.3% of patients in our cohort.

Revision for instability following reverse total shoulder arthroplasty: outcomes and risk factors for failure.

BACKGROUND: Revision of unstable reverse shoulder arthroplasty (RSA) is significantly challenging, with recurrence rates ranging from 20% to 40%. The purpose of this study was to identify factors associated with recurrent instability. The factors studied included (1) indication for revision RSA (failed primary RSA vs. failed revision RSA), (2) previous attempt at stabilization, (3) mechanism of instability, (4) clinical history of instability, and (5) surgical technique. Outcomes were reported in patients with 2-year follow-up. METHODS: All patients undergoing RSA for instability at our institution were identified. A total of 43 surgical procedures in 36 patients were included. Arthroplasty indication prior to instability (14 failed primary RSAs vs. 22 failed revision RSAs), instances of prior attempts at stabilization (14 patients treated at outside institution), mechanism-of-instability classification, clinical history of instability (17 recurrent and 26 chronic cases), and surgical technique were collected. Stability at final follow-up (minimum, 12 months) and clinical outcomes at 2-year follow-up were assessed. RESULTS: Overall, 32 of 36 patients (89%) required 38 revisions to achieve stability at final follow-up (mean, 53 ± 47 months; range, 12-210 months). On comparison of stability by indication, stability was achieved in 13 of 14 patients (93%) in the failed primary group (mean, 65 ± 59 months; range, 12-210 months) compared with 19 of 22 (86%) in the failed revision group (mean, 45 ± 36 months; range, 12-148 months; P = .365). The average number of procedures per patient was 3 (range, 2-10) in the failed primary group vs. 4.5 (range, 3-7) in the failed revision group (P = .008). Stability was achieved in 12 of 14 patients (86%) with a history of failed stabilization procedures. The most common mechanism leading to persistent instability was loss of compression. Stability was achieved in 14 of 16 patients treated for recurrent instability compared with 18 of 20 treated for chronically locked dislocation (P = .813). Continued instability occurred in 33% of patients who underwent glenoid side-only management, 33% who underwent humeral side-only management, and 10% who underwent bipolar revision tactics. At 2-year follow-up, stability was achieved in 18 of 21 patients, with improvements in the American Shoulder and Elbow Surgeons (ASES) score, forward flexion, abduction, external rotation, and the Simple Shoulder Test score (P = .016, P < .01, P = .01, P < .01, and P = .247, respectively). CONCLUSION: Patients who underwent multiple revisions after failed previous arthroplasty will require more surgical attempts to achieve stability compared with patients who underwent a revision after failed primary RSA. Loss of compression was the most common mechanism of persistent instability. Stabilization was more reliably achieved in cases of recurrent instability than in cases of chronically locked dislocation. Continued instability was noted in one-third of patients who underwent humeral side-only or glenoid side-only revisions and in 10% of those who underwent bipolar revisions. Patients in whom stabilization was successful had improved clinical outcomes.

Outcomes of femoral head allograft for the management of glenoid bone defects in revision reverse shoulder arthroplasty: a case-controlled study.

BACKGROUND: Revision shoulder arthroplasty often requires management of glenoid bone defects. Options include using allograft, harvesting iliac crest autograft, or using augmented metal components. The purpose of this study is to report outcomes of revision shoulder arthroplasty requiring management of glenoid bone defects with femoral head allograft in a large cohort of patients using a single reverse shoulder implant system and compare them to a matched cohort based on the indication for surgery. Outcomes of patients who had successful glenoid reconstruction were compared to those that required a re-revision, and to a control group that was revised without the need for bone graft. METHODS: This was a retrospective review of data collected from 2009 to 2018. There were 36 patients in the bone graft group and 52 in the control group. All patients underwent revision to a reverse shoulder arthroplasty to manage a failed total shoulder arthroplasty (n = 29 and 11), hemiarthroplasty (n = 1 and 24), or reverse shoulder arthroplasty (n = 6 and 17). All patients had a minimum of 2 yr of clinical follow-up. The primary endpoint was survival of baseplate fixation. Secondary outcomes included range of motion and functional outcome scores. Patients that had recurrent baseplate failure and were re-revised were compared to patients with bone graft that did not require additional surgery, and to patients who were revised without the need for bone graft. Patients who required revisions for reasons other than recurrent baseplate failure were also recorded. RESULTS: Five of 36 (14%) patients had recurrent baseplate failure. Mean time to failure was 12 mo. Three of 5 had successful re-implantation of another baseplate. Two of 5 were revised to a hemi arthroplasty after failure of their revisions. Preoperative American Shoulder and Elbow Surgeons scores were 31 in the grafted patients that did not require re-revision, 39 in the grafted patients that required re-revision, and 33 in the control group. Final American Shoulder and Elbow Surgeons scores were 64, 36, and 56, respectively. One patient required revision surgery not related to baseplate failure. There were no baseplate failures in the control group. CONCLUSION: The use of femoral head allograft to manage glenoid bone defects in the revision setting produces predictable improvement in functional outcomes that is not inferior to those in patients revised without bone graft. However, there is a 14% rate of baseplate failure.

Does improved external rotation following reverse shoulder arthroplasty impact clinical outcomes in patients with rotator cuff pathology and external rotation less than 0°?

BACKGROUND: The purpose of this study was to (1) evaluate whether improved external rotation (ER) in patients with preoperative ER <0° impacts their clinical outcomes following reverse shoulder arthroplasty (RSA) for rotator cuff (RC) pathology and (2) describe the differences in preoperative factors and postoperative outcomes in this patient population. Our hypothesis was that clinical outcomes would not be affected by improvement in ER using a lateralized glenosphere design. METHODS: We retrospectively reviewed 55 patients with preoperative ER <0° who underwent primary RSA for RC pathology with lateralized glenosphere. Pre- and postoperative physician-reported ER was blindly measured using a videographic review of patients externally rotating their arm at the side. Patients were evaluated using 5 different patient-reported outcome score thresholds, measured at 12 months postoperatively: (1) minimal clinically important difference (MCID) for American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) scores (ie, ≥20-point increase); (2) MCID for Simple Shoulder Test (SST) scores (≥2.4-point increase); (3) visual analog scale (VAS) for pain score >0; (4) mean ASES score (≥75); and (5) mean SST score (≥6.8), each of which was used to stratify the patients into 2 groups-greater than or equal to vs. less than the threshold. This resulted in 5 different evaluations comparing the 2 groups for any difference in postoperative ER or preoperative factors, including Hamada and Goutallier scores. RESULTS: Regardless of the measured outcome, there was no difference in either postoperative physician- or patient-reported ER between patients who achieved scores higher or lower than the thresholds. Both Hamada and Goutallier score distributions were not different between groups across all the evaluated outcomes. Patients who achieved the MCID for ASES had worse preoperative VAS pain (7 vs. 4, P = .011) and SST (1 vs. 3, P = .020) scores. Across all outcome thresholds, except MCID for SST, pain reduction (ΔVAS) was significantly more pronounced in patients exceeding the thresholds. Improved forward flexion rather than ER was observed in those who achieved the ASES (160° vs. 80°, P = .020) and SST MCIDs (150° vs. 90°, P = .037). Finally, patients who exceeded the thresholds experienced higher satisfaction rates. CONCLUSION: Improvement in ER does not appear to impact patient-reported outcome measures, including ASES and SST in patients with preoperative ER <0° undergoing RSA with a lateralized glenosphere. Patients with more severe pain and worse function at baseline experience less postoperative pain and clinically significant improvement in their reported outcomes.

Avoiding Glenoid Baseplate Fixation Failure by Altering Surgical Technique for Varying Bone Densities.

Glenoid baseplate failure is one of the causes of revision and poor outcomes in reverse shoulder arthroplasty (RSA). The objective of this study was to determine whether alterations in surgical technique can improve time-zero fixation of the baseplate in varying bone densities. A secondary objective was to identify whether preoperative radiographic glenoid sclerosis width was associated with the implementation of these techniques. Methods: This study included a biomechanical analysis and a retrospective radiographic review. The biomechanical portion describes 2 alterations to the standard surgical technique (under-preparation [A1] or over-preparation [A2] of the central screw pilot hole) and determined their torque-compression relationship via bone-substitute blocks with varying densities. Patients who underwent the described technical alterations were identified from a registry database of primary RSAs performed between 2007 and 2020. These patients were matched to patients who underwent the standard surgical technique, and preoperative radiographs were compared. Interrater reliability testing was performed to determine reproducibility. Results: With respect to the biomechanical arm, the average compressive force of the baseplate in the low-density block model when using the standard technique was 112 N compared with 300 N for the A1 technique (p = 0.01). In the high-density bone model, the standard technique resulted in failure to seat the baseplate, or screw breakage. Performing the A2 technique, the baseplate was seated without failure, with an average compressive force of 450 N. In the clinical arm, retrospective intraoperative video review for use of the alternative techniques found 20 shoulders in the "low-density" cohort and 21 in the "high-density" cohort. There was a significant difference in the glenoid sclerosis thickness between the experimental and matched control groups in our "high-density" cohort (p = 0.0014). The interrater reliability coefficient was found to be 0.69 for the "low-density" glenoid sclerosis thickness measurement and 0.92 for the "high-density" measurement. Conclusions: In low- and high-density bone models, alterations in surgical technique significantly improved compression and improved the ability to successfully seat the glenoid baseplate. Preoperative radiographs can assist in indicating the alternative technique in the sclerotic glenoid. Clinical Relevance: Utilization of these techniques intraoperatively will improve time-zero fixation of the glenoid baseplate and potentially avoid failure of fixation.

Improved mechanical fixation of an all-polyethylene glenoid reduces postoperative radiolucent lines.

BACKGROUND: The rationale for advances in implant design is to improve performance in comparison to their predecessors. The purpose of this study was to compare a newer, self-pressurizing peripheral peg glenoid to a traditional polyethylene pegged glenoid through biomechanical evaluation and a retrospective radiographic and clinical review. METHODS: Three testing conditions (uncemented, partially cemented, and fully cemented) were chosen to assess the 2 component designs in a foam block model. The number of hammer hits to seat the component, amount of time to seat the component, and resistance-to-seat were collected. The implants were then cyclically loaded following ASTM F2028-17 testing standard. Clinically, postoperative radiographs of patients with a self-pressurized glenoid component (n = 225 patients) and traditional glenoid component (n = 206 patients) were evaluated for radiolucent lines and glenoid seating at various timepoints. Clinical outcomes (American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form, Simple Shoulder Test, and visual analog scale pain scores) and complications were recorded. The presence of radiolucent lines at the bone-cement interface was evaluated using the Modified Franklin Grade and the Lazarus grade. RESULTS: The self-pressurizing glenoid design required significantly more hammer hits than traditional glenoid designs in all groups tested (P < .029). Moreover, the self-pressurizing design had significantly more resistance-to-seat than traditional components in both the uncemented and partially cemented group (P < .002). No difference in resistance-to-seat was found between designs in the fully cemented group. The uncemented and partially cemented groups did not survive the full 50,000 cycles; however the self-pressurizing design had significantly less motion than the traditional design (P < .001). No differences between component designs were found in the fully cemented group at 50,000 cycles. The self-pressurizing glenoid component had 0.005% radiographic radiolucent lines, and the traditional glenoid component had 45% radiographic radiolucent lines, with 38% of the radiolucencies in the traditional glenoid component group being defined as grade E. There were no progressive radiolucencies, differences in clinical outcomes, or complications at 2 years postoperatively. CONCLUSION: In the fully cemented condition, the 2 component designs had comparable performance; however, the differences in designs could be better observed in the uncemented group. The self-pressurizing all-polyethylene design studied has superior biomechanical stability. Clinically, the improved stability of the glenoid component correlated with a reduction of radiolucent lines and will likely lead to a reduction in glenoid component loosening.

Do preoperative factors and implant design features influence humeral stem extraction efforts?

BACKGROUND: Variations in humeral component designs in hemiarthroplasty and anatomic total shoulder arthroplasty cases can impact the degree of difficulty during a revision surgery that necessitates the removal of the humeral stem. However, no metric exists to define stem extraction effort nor to identify associated factors that contribute to extraction difficulty. The purpose of this study is to describe a method to quantify stem extraction difficulty and to define features that will impact the effort during stem removal. METHODS: This was a retrospective review of 58 patients undergoing revision of hemiarthroplasty or anatomic total shoulder arthroplasty requiring stem extraction. Each included patient had existing preoperative radiographic examination, an intraoperative video of the stem removal process, and explants available for analysis by 3 surgeons. The following factors were assessed for the impact on extraction difficulty: (1) preoperative features such as cement use, fill of proximal humerus, and stem design features; (2) intraoperative data on extraction time and bone removal; and (3) postoperative findings related to extraction artifacts (EAs). A scoring system was established to distinguish easy (Easy group) and difficult (Difficult group) stem removal cases and further used to identify the features that may affect intraoperative difficulty of stem removal. RESULTS: The Difficult group accounted for 26% (15/58) of the study population with an 18-minute average stem extraction time, average EA count of 69, and 35 mm of bone removed. The Easy group accounted for 74% (43/58) of patients, with a 4-minute average extraction time, average EA count of 23, and 10 mm of bone removed. Logistic regression model was able to correctly classify 82% of the cases, explaining 26.7% of the variance in humeral stem removal with cement and proximal coating variables. The likelihood of cemented stem removal being difficult is 5 times greater compared to an uncemented stem, and having proximal coating doubles the likelihood of a difficult stem removal compared to cases with no coating. CONCLUSIONS: Quantifying stem extraction difficulty is possible with intraoperative video as well as explant analysis. Preoperative features of the fixation type and specific features of stem design such as proximal coating will impact difficulty of stem extraction.

Machine Learning Can Predict Level of Improvement in Shoulder Arthroplasty.

The ability to accurately predict postoperative outcomes is of considerable interest in the field of orthopaedic surgery. Machine learning has been used as a form of predictive modeling in multiple health-care settings. The purpose of the current study was to determine whether machine learning algorithms using preoperative data can predict improvement in American Shoulder and Elbow Surgeons (ASES) scores for patients with glenohumeral osteoarthritis (OA) at a minimum of 2 years after shoulder arthroplasty. METHODS: This was a retrospective cohort study that included 472 patients (472 shoulders) diagnosed with primary glenohumeral OA (mean age, 68 years; 56% male) treated with shoulder arthroplasty (431 anatomic total shoulder arthroplasty and 41 reverse total shoulder arthroplasty). Preoperative computed tomography (CT) scans were used to classify patients on the basis of glenoid and rotator cuff morphology. Preoperative and final postoperative ASES scores were used to assess the level of improvement. Patients were separated into 3 improvement ranges of approximately equal size. Machine learning methods that related patterns of these variables to outcome ranges were employed. Three modeling approaches were compared: a model with the use of all baseline variables (Model 1), a model omitting morphological variables (Model 2), and a model omitting ASES variables (Model 3). RESULTS: Improvement ranges of ≤28 points (class A), 29 to 55 points (class B), and >55 points (class C) were established. Using all follow-up time intervals, Model 1 gave the most accurate predictions, with probability values of 0.94, 0.95, and 0.94 for classes A, B, and C, respectively. This was followed by Model 2 (0.93, 0.80, and 0.73) and Model 3 (0.77, 0.72, and 0.71). CONCLUSIONS: Machine learning can accurately predict the level of improvement after shoulder arthroplasty for glenohumeral OA. This may allow physicians to improve patient satisfaction by better managing expectations. These predictions were most accurate when latent variables were combined with morphological variables, suggesting that both patients' perceptions and structural pathology are critical to optimizing outcomes in shoulder arthroplasty. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Influence of preoperative factors on timing for bilateral shoulder arthroplasty.

INTRODUCTION: In bilateral shoulder arthroplasty patients, it is unclear what features are responsible for the timing of their contralateral shoulder arthroplasty. This study hypothesized that patient factors (age, gender, and hand dominance), disease factors (diagnosis and radiographic severity of contralateral shoulder), and surgical factors (type of arthroplasty) impact the timing to contralateral surgery. METHODS: A retrospective review of 332 patients treated with bilateral anatomic (TSA) or reverse (RSA) shoulder arthroplasty (172 TSA/TSA, 107 RSA/RSA, or 53 TSA/RSA) were divided into groups depending on the interval timing between arthroplasty surgeries: group 1, n = 142 (≤1 year); group 2, n = 62 (1-2 years); and group 3, n = 128 (≥2 years). Preoperative factors were analyzed to determine associations between different time groups, including age, gender, hand dominance, diagnosis, radiographic severity of contralateral shoulder, and type of surgery. Bilateral diagnoses included 211 osteoarthritis (OA), 36 cuff tear arthropathy (CTA), 13 inflammatory arthritis, 12 massive cuff tears without OA, and 4 avascular necrosis. RESULTS: OA patients had their contralateral shoulder arthroplasty sooner than CTA patients (P = .035). OA patients with arthritic changes on contralateral radiographs before the first arthroplasty had their contralateral arthroplasty sooner than those without contralateral radiographs (P < .0001). Patients who had TSA first had their contralateral arthroplasty sooner than patients who had RSA first (P = .037). DISCUSSION: This study confirmed our hypothesis identifying preoperative variables associated with different time intervals between arthroplasties. The preoperative factors associated with the highest likelihood of having contralateral shoulder arthroplasty within 1 year included OA, radiographic bilateral shoulder disease, and TSA for the first surgery.

Comparing patient-reported outcome measures and physical examination for internal rotation in patients undergoing reverse shoulder arthroplasty: does surgery alter patients' perception of function?

BACKGROUND: The purpose of this study was to evaluate how patients treated with reverse shoulder arthroplasty (RSA) achieve internal rotation (IR) using video assessment and to compare this to patient-reported outcome measures (PROMs). METHODS: We reviewed 215 preoperative and 657 postoperative videos (3-78 months) for 215 patients who underwent primary RSA, performing IR using the modified vertebral level method. Their functional motion pattern was then grouped into 3 types: type I, could not reach behind their back; type II, able to reach to at least waist level, with assistance; and type III, able to reach to a minimum of waist level in an uninterrupted fashion. Patients completed functional questions (put on a coat, wash back, tuck in a shirt, and manage toileting) and a diagram of perceived IR. Patients' functional motion types were compared to PROM answers. Pre- and postoperative scores were also compared to assess the effect of surgery on patients' perception of IR function. RESULTS: Patients undergoing RSA will achieve IR in 3 distinct motion patterns. Analysis of self-reported IR indicated statistically significant difference between the 3 functional types of IR (P < .001). Patient-perceived IR was not significantly different between the 3 studied IR functional types (P = .076) in the analysis of preoperative measures but was significantly different in the postoperative setting (P < .001). CONCLUSION: Patients attempt IR in 3 distinct functional motion patterns. The improvement of IR after RSA is measured better by patient questionnaires than by physical examination.

A cohort comparison of humeral implant designs in reverse shoulder arthroplasty: does implant design lead to lower rates of complications and revision?

INTRODUCTION: The purpose of this study was to evaluate the outcomes, revisions, and complications between a first-generation cemented modular humeral implant and a second-generation monolithic, primarily uncemented humeral implant in reverse total shoulder arthroplasty with 135° neck-shaft angle and varying degrees of metallic glenosphere offsets. METHODS: We retrospectively evaluated patients undergoing reverse total shoulder arthroplasty from 2004 to 2014 with a first-generation cemented modular humeral implant (400 patients) or second-generation monolithic humeral stem (231 patients), who had at minimum 2-year clinical and radiographic follow-up. RESULTS: Both groups of patients had similar improvement of clinical outcomes (American Shoulder and Elbow Surgeons +30 points vs. +34 points, respectively) with improvements in all planes of motion (forward flexion +70° vs. +75°, abduction +61° vs. +71°, external rotation +23° vs. +22°, and internal rotation +1.6 vs. +1.5 level improvement, respectively). The incidence of humeral loosening for the cemented group was 3.6%, whereas in the uncemented group it was 0.4% (P = .01). A total of 28 shoulders treated with the cementing technique (4.0%) and 6 patients treated with the press-fit technique (1.5%) were revised (P = .028). The rate of postoperative acromial fractures within the first year was 3.4% in the cemented group and 1.8% in the uncemented group (P = .177). CONCLUSIONS: Both the first-generation cemented modular humeral stem implant and the second-generation monolithic humeral stem implant had equivalent clinical outcomes. In addition, with the monolithic stem primarily using press-fit fixation, there was a significant reduction in the incidence of radiographic loosening and the need for revision compared with a cemented stem.

The effect of glenoid bone loss and rotator cuff status in failed anatomic shoulder arthroplasty after revision to reverse shoulder arthroplasty.

HYPOTHESIS: We evaluated outcomes and the risk of re-revision in patients with a failed anatomic total shoulder arthroplasty (TSA) revised to a reverse shoulder arthroplasty (RSA) based on rotator cuff deficiency and glenoid bone loss. METHODS: From 2004 to 2017, 123 patients with failed TSAs underwent revision to RSAs with minimum 2-year follow-up. Preoperative radiographs were evaluated to determine whether the glenoid component was fixed or loose. The rotator cuff was assessed intraoperatively and as intact or deficient. Patient outcomes including shoulder motion and American Shoulder and Elbow Surgeons (ASES) scores were obtained preoperatively and postoperatively. Patient outcomes were compared based on glenoid fixation and rotator cuff status. There were 18 TSAs revised to RSAs that underwent subsequent revision. RESULTS: The mean preoperative ASES score was 31 (95% confidence interval [CI], 29-33) with no difference in preoperative ASES scores based on glenoid status (P = .412) or rotator cuff status (P = .89). No difference in postoperative ASES score was found based on glenoid component status or rotator cuff status. However, improvement in the ASES score was greater with an intact rotator cuff (mean postoperative score, 67 [95% CI, 57-76] vs. 55 [95% CI, 50-60]; P = .025). The overall re-revision rate was 11.4%, with a mean time to re-revision of 22 months (range, 0-89 months). The odds ratio was 1.786 for subsequent revision in patients with glenoid loosening compared with those without loose glenoids on preoperative radiographs. CONCLUSION: There was an overall improvement in patient outcomes for failed TSAs revised to RSAs; however, patients with an intact cuff had a greater improvement in ASES scores.

Optimizing humeral stem fixation in revision reverse shoulder arthroplasty with the cement-within-cement technique.

BACKGROUND: The purpose of this study was to report on the clinical outcomes of patients undergoing revision reverse shoulder arthroplasty (RSA) by the cement-within-cement technique, as well as to identify whether surgical technique can affect subsequent humeral loosening. METHODS: In 98 patients, cemented humeral components that were revised to RSA using the cement-within-cement technique were identified and included in this study. We compared 8 patients in whom humeral stem loosening developed with 90 patients whose stem remained fixed. Preoperative and postoperative radiographs of each patient were downloaded in DICOM (Digital Imaging and Communications in Medicine) format and analyzed in Mimics. The total area of the cement mantle (in square millimeters) and of the stem (in square millimeters), as visualized on 2-dimensional plain films, was measured in each subject on both preoperative and postoperative radiographs. Outcomes at a minimum of 2 years of follow-up were analyzed. RESULTS: Clinical outcomes were available in 57 patients, with a mean follow-up period of 54 months (range, 21-156 months). Patients demonstrated significantly improved functional outcome scores and shoulder range of motion. In the group without loosening, the mean increase in the cement mantle area was 4380 ± 12701 mm2 (P < .0001). In the group with loosening, the mean increase in the cement mantle area was only 811 ± 4014 mm2 (P = .484). CONCLUSIONS: Use of the cement-within-cement technique for fixation of the humeral component in revision RSA is effective in improving functional outcome scores and shoulder range of motion. Furthermore, these findings suggest that efforts to maximize the cement volume during reimplantation may lessen the chance of humeral stem loosening requiring additional revision.

Defining the younger patient: age as a predictive factor for outcomes in shoulder arthroplasty.

BACKGROUND: The purpose of this study was to define an age cutoff at which clinical outcomes and revision rates differ for patients undergoing primary anatomic total shoulder arthroplasty (TSA) and patients undergoing primary reverse shoulder arthroplasty (RSA). METHODS: This retrospective cohort study included 1250 primary shoulder arthroplasties (1131 patients) with minimum 2-year clinical follow-up (mean, 50 months [range, 24-146 months]). TSA (n = 518; mean age, 68.1 years [range, 28-90 years]) was performed for osteoarthritis in most cases (99%), whereas the primary diagnoses for RSA (n = 732; mean age, 70.8 years [range, 22-91 years]) included rotator cuff arthropathy (35%), massive cuff tear without osteoarthritis (29.8%), and osteoarthritis (20.5%). Outcomes included range of motion, the American Shoulder and Elbow Surgeons (ASES) score, and the revision rate. The relationship between age at the time of surgery in 5-year increments (46-50 years, 51-55 years, and so on) and the revision rate was examined to identify the age cutoff; this was then used to assess clinical outcomes. RESULTS: In patients younger than 65 years, TSA was associated with a 3.4-fold increased risk of revision (P = .01). RSA performed in patients younger than 60 years was associated with a 4.8-fold increased risk of revision (P < .001). TSA patients aged 65 years or older and RSA patients aged 60 years or older had better total ASES scores (82 vs. 77 [P = .03] and 72 vs. 62 [P = .002], respectively) and better internal rotation (interquartile range, TSA 5-6 vs. 4-5 [P = .002] and RSA 4-5 vs 3-4 [P = .04])-where 6 represents T4 to T6 and 4 represents T11 to L1-than their younger counterparts. CONCLUSION: Age at index arthroplasty affects outcomes and the risk of revision. Primary TSA patients younger than 65 years and RSA patients younger than 60 years have a significantly increased revision risk. These age cutoffs are also correlated with differences in ASES scores and internal rotation.

Acute surgical management of proximal humerus fractures: ORIF vs. hemiarthroplasty vs. reverse shoulder arthroplasty.

BACKGROUND: Proximal humerus fracture treatment varies by surgeon preference and patient factors. This study compares patient and fracture characteristics, with outcomes between current surgical treatment options. METHODS: Between 1999 and 2018, 425 proximal humerus fractures underwent acute surgical management: open reduction internal fixation (ORIF, n = 211), hemiarthroplasty (HA, n = 108), or reverse shoulder arthroplasty (RSA, n = 106). Patient and fracture characteristics included age, American Society of Anesthesiologists physical status classification (ASA), and fracture classification. Postoperative motion at 3, 6, and minimum 12 months (avg 20 ± 21 months), radiographic outcomes, and postoperative falls were analyzed. RESULTS: Average age for treatment groups was 65 ± 13 years (range: 18-93 years). Fractures were classified as 2- (11%), 3- (41%), or 4-part (48%). Age, ASA, and fracture classification were associated with selected surgical management (P < .0001, =.001, <.0001, respectively). Outcomes showed a significant improvement in forward flexion from 3 months to 6 months in all groups (P < .0001). No difference in final motion was seen between groups. Radiographic union was higher in ORIF (89%), and similar between HA (79%) and RSA (77%, P = .005). Rate of reoperation was RSA 6.6%, ORIF 17.5%, and hemiarthroplasty 15.7% (P = .029). Postoperatively, 23% patients had at least 1 fall, of which 73% resulted in fractures. CONCLUSION: Older patients with high ASA were treated with arthroplasty, and younger patients with lower ASA were treated with ORIF. All groups showed improvements in motion. At minimum 1 year of follow-up, there was no difference in motion between groups. ORIF and HA showed significantly more reoperations compared with RSA. Patients should be counseled about reoperation, fall risk, and prevention.

Does the etiology of a failed hemiarthroplasty affect outcomes when revised to a reverse shoulder arthroplasty?

BACKGROUND: The purposes of this study were to evaluate patient outcomes after revision of hemiarthroplasty to reverse shoulder arthroplasty (RSA) based on initial pathology, to determine the re-revision rate, and to identify characteristics that may predict subsequent re-revision. METHODS: A total of 207 shoulder hemiarthroplasty, bipolar prosthesis, and humeral resurfacing cases revised to RSA between January 2004 and January 2017 were reviewed. Outcome measures included shoulder motion and American Shoulder and Elbow Surgeons and Simple Shoulder Test (SST) scores. Sixteen RSAs underwent re-revision. A case-control study with each revised RSA matched to 4 controls based on age, sex, and minimum 2-year follow-up was performed to evaluate for factors predicting re-revision. RESULTS: The mean time from initial hemiarthroplasty to RSA was 3.6 years (range, 0.1-20 years). There were 114 patients with a minimum of 2 years' follow-up (mean, 57 months; range, 24-144 months). The most common initial diagnoses for hemiarthroplasty were fracture (n = 72), cuff tear arthropathy (CTA) (n = 22), and osteoarthritis (OA) (n = 20). Overall mean scores and range-of-motion values were as follows: American Shoulder and Elbow Surgeons score, 59 (95% confidence interval [CI], 54-64); SST score, 4 (95% CI, 4-5); forward flexion, 106° (95% CI, 96°-116°); and abduction, 95° (95% CI, 85°-105°). Compared with fracture cases, CTA cases had better forward flexion (P = .01) and abduction (P = .006) and OA cases had better SST scores (P = .02) and abduction (P = .04). The re-revision rate was 7.7% at a mean of 31 months (range, 0-116 months), with the most common diagnosis being fracture (10 of 16 cases). Humeral loosening (8 of 16 cases) was the most common failure mechanism, and larger glenosphere sizes were more likely to be revised. CONCLUSION: Functional outcome scores of hemiarthroplasty cases revised to RSA were better for patients with OA than for patients with CTA or fracture. Cases of hemiarthroplasty for fracture had decreased motion after revision to RSA compared with CTA and OA. Humeral loosening was the most common failure mechanism.

Is there a relationship between preoperative diagnosis and clinical outcomes in reverse shoulder arthroplasty? An experience in 699 shoulders.

BACKGROUND: The influence of diagnosis on outcomes after reverse shoulder arthroplasty (RSA) is not completely understood. The purpose of this study was to compare clinical outcomes of different pathologies. METHODS: A total of 699 RSAs were performed for the following diagnoses: (1) rotator cuff tear arthropathy (RCA), (2) massive cuff tear (MCT) with osteoarthritis (OA), (3) MCT without OA, (4) OA, (5) acute proximal humeral fracture, (6) malunion, (7) nonunion, and (8) inflammatory arthropathy. All patients had minimum 2-year clinical follow-up (mean, 47 months; range, 24-155 months). Range of motion, Simple Shoulder Test scores, American Shoulder and Elbow Surgeons scores, visual analog scale scores for function, and health-related quality-of-life measures were obtained preoperatively and postoperatively. RESULTS: The RCA, MCT-with-OA, MCT-without-OA, and OA groups all exhibited significant improvements in all outcome scores and in all planes of motion from preoperatively until a minimum of 2 years postoperatively. The malunion, nonunion, and inflammatory arthropathy groups showed improvements in American Shoulder and Elbow Surgeons scores, Simple Shoulder Test scores, forward flexion, and abduction. The average changes for all other outcomes and planes of motions were also positive but did not reach statistical significance. After adjustment for age and compared with RCA, female patients with malunion had significantly poorer forward flexion (P < .05), those with OA had significantly better abduction (P < .05), and those with fractures had significantly worse patient satisfaction (P < .05). Among male patients, those with MCTs without OA had significantly worse satisfaction (P < .05). CONCLUSION: RSA reliably provides improvement regardless of preoperative diagnosis. Although subtle differences exist between male and female patients, improvements in clinical outcome scores were apparent after RSA.