Memory T lymphocyte hyporesponsiveness to non-cognate stimuli: a key factor in age-related immunodeficiency

Previous studies from our laboratory have suggested that aging leads to an accumulation of cells expressing high levels of CD44, thought to be a marker for memory lymphocytes, and that positively selected CD44hi T cells, from mice of any age, respond poorly to concanavalin A (Con A) in limiting dilution estimates of interleukin (IL)-2-producing cells. We now report the results of a more comprehensive analysis of memory T cell function, in old and young mice, to non-cognate activators (Con A and the staphylococcal enterotoxin SEB). We report that memory T cells, isolated by removing cells bearing the CD45RB determinant, contain very few cells able to respond to either Con A or SEB under limiting dilution culture conditions, whether the responses are measured by IL-2 or by IL-3 accumulation. As a control, we show that memory T cells do respond strongly, at limiting dilution, to recently encountered priming antigens, i.e. Schistosoma mansoni egg antigen; the limiting dilution culture protocol thus does not preclude activation of memory T cells when cognate stimuli are presented to antigen-specific cells. These data suggest that virgin and memory T cells may differ fundamentally in their activation requirements, and suggest further that the accumulation, with age, of memory T cells accounts for the low responsiveness of old mice to non-cognate mitogens.

Systematic underreporting of cutaneous malignant melanoma in Massachusetts. Possible implications for national incidence figures

An independent tabulation of incidence of cutaneous malignant melanoma in Massachusetts indicates that 12% and perhaps as many as 19% of new cases of cutaneous malignant melanoma in Massachusetts are not recorded in the Massachusetts Cancer Registry, significantly more than the expected 5% (p = 0.0001). The increasing number of nonhospital medical settings in which melanomas can be diagnosed and/or treated appears to account for this discrepancy. We suspect that these findings in Massachusetts also apply to cancer reporting systems in other regions of the United States. We suggest that the true incidence of cutaneous malignant melanoma in Massachusetts, and perhaps in the United States, may be significantly higher than reported.

Palisading prostate granulomas following surgery

Fifteen cases of palisading granulomas of the prostate occurring in patients with a history of previous prostate surgery are described and illustrated. This distinctive histologic lesion strongly resembles a rheumatoid nodule, but is not associated with connective tissue disease or infection and is probably related to prior transurethral prostatectomy or needle biopsy.

Posterior Tibial Slope is Increased in Patients With Tibial Tubercle Fractures and Osgood-Schlatter Disease

BACKGROUND

Osgood-Schlatter disease (OSD) and tibial tubercle fractures are pathologies that affect the tibial tubercle apophysis in preadolescents and adolescents. Anatomic alignment of the proximal tibia may explain why some children develop OSD or sustain tibial tubercle fractures and some do not. Recent data has shown an association between posterior tibial slope angle (PTSA) and both OSD and proximal tibia physeal fractures. In this study, we compare radiographic parameters between patients with non-OSD knee pain, knees with OSD, and knees with tibial tubercle fracture to elucidate a difference between these groups.

METHODS

Patients treated for OSD, tibial tubercle fractures, and knee pain, from 2012 to 2018, were retrospectively reviewed. Radiographic parameters for each study group included PTSA, anatomic lateral distal femoral angle, anatomic medial proximal tibial angle, patellar articular height, and the distance from the inferior aspect of the patellar articular surface. Caton-Deschamps index was then calculated. Demographic data was collected including age, sex, and body mass index. Demographic and radiographic data was compared using analysis of variance tests, χ2 tests, 2-sample t tests, and multiple linear regression.

RESULTS

Two hundred fifty-one knees in 229 patients met inclusion criteria for the study. In all, 76% were male and the average age of the overall cohort was 14 years old. In patients with tibial tubercle fractures, the majority of fractures were Ogden type 3b (65%). After controlling for demographic variability, average PTSA in the fracture cohort was significantly greater than that in the control cohort (β=3.49, P<0.001). The OSD cohort had a significantly greater posterior slope (β=3.14) than the control cohort (P<0.001). There was no statistically significant difference between the fracture and OSD cohorts. There was also no difference in Caton-Deschamps index between the 2 study groups when compared with the control group.

CONCLUSION

This study demonstrates that patients with tibial tubercle fractures and patients with OSD have an increased PTSA when compared with the control group. This information adds to the body of evidence that increased tibial slope places the proximal tibial physis under abnormal stress which may contribute to the development of pathologic conditions of proximal tibia such as OSD and tibial tubercle fractures.

LEVEL OF EVIDENCE

Level III; retrospective comparative study.

Risk of revision based on timing of corticosteroid injection prior to shoulder arthroplasty

AIMS

Corticosteroid injections are often used to manage glenohumeral arthritis in patients who may be candidates for future total shoulder arthroplasty (TSA) or reverse shoulder arthroplasty (rTSA). In the conservative management of these patients, corticosteroid injections are often provided for symptomatic relief. The purpose of this study was to determine if the timing of corticosteroid injections prior to TSA or rTSA is associated with changes in rates of revision and periprosthetic joint infection (PJI) following these procedures.

METHODS

Data were collected from a national insurance database from January 2006 to December 2017. Patients who underwent shoulder corticosteroid injection within one year prior to ipsilateral TSA or rTSA were identified and stratified into the following cohorts: < three months, three to six months, six to nine months, and nine to 12 months from time of corticosteroid injection to TSA or rTSA. A control cohort with no corticosteroid injection within one year prior to TSA or rTSA was used for comparison. Univariate and multivariate analyses were conducted to determine the association between specific time intervals and outcomes.

RESULTS

In total, 4,252 patients were included in this study. Among those, 1,632 patients (38.4%) received corticosteroid injection(s) within one year prior to TSA or rTSA and 2,620 patients (61.6%) did not. On multivariate analysis, patients who received corticosteroid injection < three months prior to TSA or rTSA were at significantly increased risk for revision (odds ratio (OR) 2.61 (95% confidence interval (CI) 1.77 to 3.28); p < 0.001) when compared with the control cohort. However, there was no significant increase in revision risk for all other timing interval cohorts. Notably, Charlson Comorbidity Index ≥ 3 was a significant independent risk factor for all-cause revision (OR 4.00 (95% CI 1.40 to 8.92); p = 0.036).

CONCLUSION

There is a time-dependent relationship between the preoperative timing of corticosteroid injection and the incidence of all-cause revision surgery following TSA or rTSA. This analysis suggests that an interval of at least three months should be maintained between corticosteroid injection and TSA or rTSA to minimize risks of subsequent revision surgery. Cite this article: Bone Joint J 2022;104-B(5):620-626.

Genetic control of cutaneous basophil hypersensitivity

CBH to DNP-GL could be elicited only in responder guinea pigs which possess the genetic ability to develop classic delayed type hypersensitivity to DNP-PLL, the response to which is governed by the same gene. Since the defect in nonresponder animals seems to reside at the level of their T cells and not B cells, these results lend support to the contention that CBH, as well as DH, is dependent on and probably mediated by T cells.

Conversion Total Knee Arthroplasty

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Conversion total knee arthroplasty (TKA) represents a heterogeneous group of procedures and most commonly includes TKA performed after ligamentous reconstruction, periarticular open reduction and internal fixation (ORIF), high tibial osteotomy (HTO), and unicompartmental knee arthroplasty (UKA).

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Relative to patients undergoing primary TKA, patients undergoing conversion TKA often have longer operative times and higher surgical complexity, which may translate into higher postoperative complication rates.

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There is mixed evidence on implant survivorship and patient-reported outcome measures when comparing conversion TKA and primary TKA, with some studies noting no differences between the procedures and others finding decreased survivorship and outcome scores for conversion TKA.

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By gaining an improved understanding of the unique challenges facing patients undergoing conversion TKA, clinicians may better set patient expectations, make intraoperative adjustments, and guide postoperative care.

Trends in Venous Thromboembolism After Shoulder Arthroplasty in the United States: Analysis Following the 2009 American Academy of Orthopaedic Surgeons Clinical Practical Guidelines

BACKGROUND

In 2009, the American Academy of Orthopaedic Surgeons released a consensus recommending venous thromboembolism (VTE) prophylaxis after total shoulder arthroplasty (TSA). The purpose of this study was to examine the (1) change in incidence of 90-day VTE, deep vein thrombosis (DVT), and pulmonary embolism; (2) change in utilization of chemoprophylaxis; and (3) change in the economic burden associated with VTE after TSA from 2010 to 2019.

METHODS

Using the PearlDiver database, national data from 2010 to 2019 were used to identify patients who underwent primary TSA for osteoarthritis and/or rotator cuff arthropathy. Exclusions entailed liver pathology, coagulopathy, or those on prior prescribed blood thinners before TSA. Multivariable regression was used controlling for age and Charlson Comorbidity Index for all years with 2010 as the reference year.

RESULTS

From 2010 to 2019, there was a reduction in VTE rates from 0.89% in 2010 to 0.78% in 2019. Regarding implant type, there was no notable change in incidence of VTE, DVT, and pulmonary embolism within 90 days after anatomic TSA. Notable reductions were observed in both VTE and DVT after reverse TSA from 2010 to 2019. Prescribed chemical VTE prophylaxis utilization after TSA markedly increased from 4.41% in 2010 to 11.70% utilization in 2019. The utilization of aspirin markedly increased from 17.27% in 2010 to 65.17% in 2019. Among anticoagulants, the utilization of direct factor Xa inhibitors increased from 0.0% utilization in 2010 to 66.09% utilization in 2019. The added reimbursements associated with VTE after TSA markedly decreased from $14,122 in 2010 to $4,348 in 2019.

CONCLUSION

The incidence and economic burden associated with VTE after TSA have markedly declined following the 2010 American Academy of Orthopaedic Surgeons clinical practice guidelines. This reduction can be attributed to both an increase in VTE prevention through increased utilization of prescribed chemoprophylaxis and improvement in VTE treatment strategies.

LEVEL OF EVIDENCE

Therapeutic, III.

Complications following regional anesthesia versus general anesthesia for the treatment of distal radius fractures

PURPOSE

Open reduction and internal fixation (ORIF) are commonly utilized for the repair of distal radius fractures (DRF). While general anesthesia (GA) is typically administered for ORIF, recent studies have also demonstrated promising results with the usage of regional anesthesia (RA) in the surgical treatment of distal radius fractures. This study will compare complication rates between the use of RA versus GA for ORIF of DRFs.

METHODS

A multi-institutional surgical registry was utilized to identify patients who had undergone ORIF for DRFs from 2005 to 2018-these patients were stratified into GA and RA cohorts. Patients were matched utilizing coarsened-exact-matching (CEM) to compare postoperative outcomes and rates of 30-day complications were compared between the two cohorts.

RESULTS

Upon CEM-matching, 1191 patients receiving RA were matched to 9250 patients who had received GA, with a multivariate imbalance measure (L1) statistic of < 0.001. In the matched-cohort analysis, no significant differences were observed in rates of any complication (all p ≥ 0.083). On multivariate regression analyses, RA was not associated with increased risk for any complication (p = 0.445), minor complications (p = 0.093), major complications (p = 0.758), unplanned reoperations (p = 0.355), unplanned readmissions (p = 0.799), or mortality (p = 0.579).

CONCLUSION

With similar safety profiles, RA is a safe and reasonable alternative to GA when managing DRFs surgically. RA may be the preferred anesthetic technique for ORIF of DRFs in patients at high risk with GA, such as those with reactions to GA in the past or with significant cardiopulmonary risk factors.

Social determinants of health disparities impact postoperative complications in patients undergoing total shoulder arthroplasty

BACKGROUND

Understanding the role of social determinants of health disparities (SDHDs) in surgical outcomes can better prepare providers to improve postoperative care. In this study, we use International Classification of Diseases (ICD) codes to identify SDHDs and investigate the risk of postoperative complication rates among patients undergoing total shoulder arthroplasty (TSA).

METHODS

A retrospective cohort analysis was conducted using a national insurance claims database. Using ICD and Current Procedural Terminology (CPT) codes, patients who underwent primary TSA with at least 2 years of follow-up in the database were identified. Patients with a history of SDHDs were identified using appropriate ICD-9 and ICD-10 codes. Patients were grouped in one of 2 cohorts: (1) patients with no history of SDHDs (control) and (2) patients with a history of SDHDs (SDHD group) prior to TSA. The SDHD and control groups were matched 1:1 for comorbidities and demographics prior to conducting multivariable analysis for 90-day medical complications and 2-year surgical complications.

RESULTS

After matching, there were 8023 patients in the SDHD group and 8023 patients in the control group. The SDHD group had significantly higher odds for 90-day medical complications including heart failure, cerebrovascular accident, renal failure, deep vein thrombosis, pneumonia, sepsis, and urinary tract infection. Additionally, the SDHD group had significantly higher odds for revision surgery within 2 years following TSA. Patients in the SDHD group also had a significantly longer length of hospital stay following TSA.

DISCUSSION

This study highlights the association between SDHDs and postoperative complications following TSA. Quantifying the risk of complications and differences in length of stay for TSA patients with a history of SDHDs is important in determining value-based payment models and risk stratifying to optimize patient care.

Mismatched implants yield comparable outcomes in revision shoulder arthroplasty

BACKGROUND

Revision shoulder arthroplasty procedures pose unique challenges to shoulder surgeons. Efforts to mitigate bone loss, blood loss, operative time, and intraoperative complications may prompt the surgeon to consider retaining well-fixed components and combine them with components of a different manufacturer. This concept, known as mismatching, represents a viable solution to a dilemma encountered in the revision setting. The purpose of this study is to compare the clinical outcomes between patients treated with matched vs. mismatched implants in revision shoulder arthroplasty.

METHODS

All revision shoulder arthroplasty cases performed by a single surgeon between 2012 and 2022 were reviewed. Using radiographs and operative reports, 44 patients were identified as mismatches, defined by humeral and glenoid components made by 2 different manufacturers. Demographic data, preoperative and postoperative range of motion, and patient-reported outcomes measures (American Shoulder and Elbow Surgeons, visual analog scale, Simple Shoulder Test, and stability) were collected. A larger cohort of all revision arthroplasties by the same surgeon (n = 574) was then used to perform a matched cohort analysis based on indication for revision. Rate of re-revision and patient-reported outcomes were then compared using simple statistics.

RESULTS

Twenty-five of the 44 total mismatches had a minimum of 1-year follow-up. Indications for revision included 13 failed reverse shoulder arthroplasty, 9 failed anatomic total shoulder arthroplasty, and 3 failed hemiarthroplasty. All were revised to reverse shoulder arthroplasty. In the matched cohort analysis (n = 25 mismatches and n = 281 matches), there were no differences in mean American Shoulder and Elbow Surgeons score, visual analog scale pain score, or Simple Shoulder Test at 1 year postoperatively. However, stability was significantly higher for mismatches (5.9) than for matches (3.5) on a 0-10 scale, with 10 being most stable (P = .039). There was an 11% (n = 5) re-revision rate among mismatches, compared with 13% among matches in the total revision cohort. Of the 44 total manufacturer-mismatched cases, 11 were also size-mismatched (differing glenosphere and socket size), and none of these required re-revision within the available short-term follow-up period.

DISCUSSION

Patients treated with mismatched components in this study demonstrated similar clinical outcomes and revision rates to those treated with matched components in revision shoulder arthroplasty. Although promising, these results are limited by a small sample size and short-term follow-up. A more definitive conclusion about the practice of mismatching implants will require further research with larger data sets and longer follow-up.

Quantification of Glenoid Dysplasia Utilizing Vault Depth: A Classification and Treatment Guide

BACKGROUND

Glenoid dysplasia is an infrequent cause of glenohumeral osteoarthritis. However, significant variability in the characteristics and severity of pathology may impact treatment choice and outcomes. The purpose of this study was to subclassify glenoid dysplasia and determine if the severity of dysplasia affected the type of reconstruction and its clinical outcomes in our patient population.

METHODS

This is a retrospective, single-surgeon cohort study where patients with glenoid dysplasia (Walch C) who underwent primary anatomic total shoulder arthroplasty (TSA) or reverse shoulder arthroplasty (RSA) were identified. Their radiographs and axial computed tomography (CT) cuts were analyzed subjectively using retroversion and bone stock and classified as structural (Walch C1) or combined (Walch C2) glenoid deformity and graded as either mild or severe by at least 2/3 agreement and validated using reliability analysis. To quantify morphology, three-dimensional models were created from CT scans. The primary outcome measure was ASES score at final follow-up and was used to compare the type of arthroplasty (TSA vs. RSA) and severity grade. The threshold delineating mild from severe deformity was also assessed.

RESULTS

Forty-five patients (54 shoulders) were included. Median age was 66.5 years (interquartile range [IQR] 59.0-72.1 years). The cohort comprised 27 TSAs and 27 RSAs with median follow-up of 58 months (IQR 33-84 months). Thirty-seven glenoids were classified as C1, 17 as C2. There were 36 mild and 18 severe deformities. There was no significant difference between dysplasia groups by severity in median preoperative glenoid inclination (Mild: 6.0° vs. Severe: 7.1°, p = 0.353) or version (Mild: 28.8° vs. Severe: 36.0°, p = 0.060). Vault depth was less in the severe group (Mild: 14.6 mm vs. Severe: 7.6 mm, p < 0.001). No differences found in median ASES score at final follow-up between severity groups (Mild: 95.0 vs. Severe: 93.5, p = 0.597) or arthroplasty types (TSA: 92.6 vs. RSA: 95.8, p = 0.529). The mild cohort comprised 23 TSAs (63.9%) and 13 RSAs, whereas the severe cohort comprised 4 TSAs and 14 RSAs (77.8%, p = 0.008).

CONCLUSIONS

Glenoid dysplasia can be differentiated into mild and severe deformity. TSAs and RSAs did not have significant differences in outcomes despite differences in severity. Vault depth differentiates mild and severe glenoid dysplasia and provides a threshold that helps guide reconstruction type selection.

Impact of preoperative urinary tract infection on postoperative outcomes following total shoulder arthroplasty for osteoarthritis

Introduction

As the utilization of total shoulder arthroplasty (TSA) increases, it is essential to identify risk factors associated with postoperative complications. Urinary tract infection (UTI) is one such example. Our objective is to identify whether UTI is associated with increased rates of prosthetic joint infection (PJI) and determine whether its treatment reduces PJI rates.

Methods

Patients who underwent primary TSA for glenohumeral osteoarthritis between 2010 and 2019 with minimum two-year follow-up were identified in a national database (PearlDiver Technologies) using Current Procedural Terminology and International Classification of Diseases codes. These patients were stratified into two cohorts: those with preoperative UTI within two weeks of TSA and those without. The preoperative UTI cohort was stratified into those treated and those untreated prior to TSA. Univariate and multivariable analyses were performed.

Results

Following multivariable analysis, there were significantly higher odds of postoperative anemia, pulmonary embolism, and death in the UTI cohort. Comparing treated to untreated UTI, there were no significant differences in multivariable analysis for any 90-day medical or two-year surgical complications.

Discussion

This study showed that UTI was not associated with increased rates of PJI. UTI was, however, associated with postoperative medical complications that surgeons should be aware of.

Debridement Technique for Single-Stage Revision Shoulder Arthroplasty

Background

The incidence of revision shoulder arthroplasty continues to rise, and infection is a common indication for revision surgery. Treatment of periprosthetic joint infection (PJI) in the shoulder remains a controversial topic, with the literature reporting varying methodologies, including the use of debridement and implant retention, single-stage and 2-stage surgeries, antibiotic spacers, and resection arthroplasty20. Single-stage revision has been shown to have a low rate of recurrent infection, making it more favorable because it precludes the morbidity of a 2-stage operation. The present video article describes a meticulous debridement technique as it applies to revision shoulder arthroplasty.

Description

The previous deltopectoral incision should be utilized, with extension 1 to 1.5 cm proximally and distally, removing any draining sinuses. First, develop subcutaneous flaps above the muscle layer to better establish normal tissue planes. A large medial subcutaneous flap will allow for identification of the superior border of the pectoralis major. The pectoralis can be traced laterally to its humeral insertion, which is often in confluence with the deltoid insertion. Hohmann retractors can be placed sequentially, working distal to proximal, under the deltoid in order to recreate the subdeltoid space. Next, reestablish the subpectoral space by releasing any scar tissue tethering the pectoralis muscle and conjoined tendon. Dislocate the prosthesis and remove modular components. Restore the subcoracoid space by dissecting between the subscapularis and the conjoined tendon, allowing for axillary nerve identification. Complete a full capsular excision circumferentially around the glenoid, taking care to protect the axillary nerve as it passes from the subcoracoid space under the inferior glenoid to the deltoid muscle. The decision to remove well-fixed components should be made by the surgeon. Any exposed osseous surfaces should undergo debridement to reduce bacterial burden. Reimplantation should focus on obtaining stable bone-implant interfaces to minimize any micromotion that may increase risk of reinfection. Our preference is to irrigate with 9 L of normal saline solution, Irrisept (Irrimax), and Bactisure Wound Lavage (Zimmer Biomet). Multiple cultures should be taken and followed carefully postoperatively to allow tailoring of the antibiotic regimen with infectious disease specialists.

Alternatives

Two-stage revision is the most common alternative treatment for shoulder PJI and consists of removal of components, debridement, and delayed component reimplantation; however, it requires at least 1 return to the operating room for definitive treatment.

Rationale

Serum laboratory studies and joint aspiration are not reliable predictors of shoulder PJI because of the high rate of Cutibacterium acnes infections21,22. The incidence of unexpected positive cultures in seemingly aseptic revisions ranges from 11% to 52.2%6-8,23,24. It is prudent for all revision shoulder arthroplasties to be treated as involving a presumed infection, with thorough debridement, because of the high rate of unexpected positive cultures and the greater prevalence of low-virulence organisms in shoulder arthroplasty for PJI.

Expected Outcomes

The International Consensus Meeting guidelines for PJI were developed in 2018, and patients with higher Infection Probability Scores are theorized to have higher rates of recurrence19,21. With meticulous debridement, the rate of recurrent infections requiring reoperation is just 5% following 1-stage revision shoulder arthroplasty, averaged across all Infection Probability Scores19.

Important Tips

Ensure that an adequate incision is made in order to allow for identification of the deltoid origin on the clavicle and insertion on the humerus.The superior border of the pectoralis major can be traced laterally to the humerus to correctly identify the deltopectoral interval.Subdeltoid dissection is complete when you are able to identify deep deltoid fibers superficially, rotator cuff tendon posteriorly, and humeral bone. Exposure can be improved by abducting and internally rotating the humerus.Capsule excision around the glenoid is complete when the subscapularis can be visualized anteriorly, the fatty tissue of the inferior glenoid space inferiorly, and the rotator cuff tendon (or subdeltoid space if the cuff is absent) posteriorly and superiorly.

Acronyms and Abbreviations

PJI = periprosthetic joint infectionC. acnes = Cutibacterium acnesUPC = unexpected positive cultureIS score = Infection Probability ScoreDAIR = debridement, antibiotics, and implant retentionCT = computed tomographyWBC = white blood cellCRP = C-reactive proteinESR = erythrocyte sedimentation rateCHG = chlorhexidine gluconateAC = acromioclavicularGT = greater tuberositySGHL = superior glenohumeral ligament.

Risk Factors for Blood Transfusions in Primary Anatomic and Reverse Total Shoulder Arthroplasty for Osteoarthritis

BACKGROUND

The purpose of this study was to determine risk factors for blood transfusion in primary anatomic and reverse total shoulder arthroplasty (TSA) performed for osteoarthritis.

METHODS

Patients who underwent anatomic or reverse TSA for a diagnosis of primary osteoarthritis were identified in a national surgical database from 2005 to 2018 by utilizing both CPT and ICD-9/ICD-10 codes. Univariate analysis was performed on the two transfused versus non-transfused cohorts to compare for differences in comorbidities and demographics. Independent risk factors for perioperative blood transfusions were identified via multivariate regression models.

RESULTS

305 transfused and 18,124 nontransfused patients were identified. Female sex (p<0.001), age >85 years (p=0.001), insulin-dependent diabetes mellitus (p=0.001), dialysis dependence (p=0.001), acute renal failure (p=0.012), hematologic disorders (p=0.010), disseminated cancer (p<0.001), ASA ≥ 3 (p<0.001), and functional dependence (p=0.001) were shown to be independent risk factors for blood transfusions on multivariate logistic regression analysis.

CONCLUSION

Several independent risk factors for blood transfusion following anatomic/reverse TSA for osteoarthritis were identified. Awareness of these risk factors can help surgeons and perioperative care teams to both identify and optimize high-risk patients to decrease both transfusion requirements and its associated complications in this patient population. Level of Evidence: III.

Reverse total shoulder arthroplasty within 6 weeks of proximal humerus fracture is associated with the lowest risk of revision

BACKGROUND

Reverse total shoulder arthroplasty (RTSA) has become an increasingly popular treatment strategy in the management of complex proximal humeral fractures (PHFs). However, no definitive consensus has been reached regarding the optimal surgical timing of RTSA following PHF, particularly considering nonoperative management is often a viable option. Therefore, the aim of this study was (1) to identify optimal timing intervals that maximize the likelihood of revision following RTSA and (2) to determine differences in revision etiologies using the identified timing intervals.

METHODS

A retrospective cohort analysis of patients undergoing PHF-indicated RTSA from 2010 to 2021 was conducted using a national administrative claims database. Stratum-specific likelihood ratio (SSLR) analysis was conducted to determine data-driven timing strata between PHF and RTSA that maximized the likelihood of revision surgery within 2 years of RTSA. To control for confounders, multivariable regression analysis was conducted to confirm the identified data-driven strata's association with 2-year revision rates as well as compare the likelihood of various indications for revision including mechanical loosening, dislocation, periprosthetic joint infection (PJI), and periprosthetic fracture (PPF).

RESULTS

In total, 11,707 patients undergoing TSA following PHF were included in this study. SSLR analysis identified 2 timing categories: 0-6 weeks and 7-52 weeks from the time of PHF to TSA surgery. Relative to the 0-6-week cohort, the 7-52-week cohort was more likely to undergo revision surgery within 2 years (OR 1.93, P < .001). Moreover, the 7-52-week cohort had significantly higher odds of revision indicated for dislocation (OR 2.24, P < .001), mechanical loosening (OR 1.71, P < .001), PJI (OR 1.74, P < .001), and PPF (OR 1.96, P < .001).

CONCLUSIONS

Using SSLR, we were successful in identifying 2 data-driven timing strata between PHF and RTSA that maximized the likelihood of 2-year revision surgery. As it can be difficult to determine whether RTSA or nonoperative management is initially more appropriate, considering the results of this study, an early trial of 4-6 weeks of nonoperative management may be appropriate without altering the risks associated with RTSA.

Increased revision rates in shoulder arthroplasty following shoulder arthroscopy

Introduction

Total shoulder arthroplasty (TSA) and reverse TSA (rTSA) are successful treatments for end-stage shoulder arthritis. However, it is unknown whether prior arthroscopy is associated with an increased risk for revision surgery. This study investigates if undergoing a shoulder arthroscopy in the year prior to primary arthroplasty increases risk of revision surgery within 2 years.

Methods

Patients who underwent TSA or rTSA between 2005 and 2017 were identified in a natinal claims database and stratified into two cohorts: (1) individuals with a history of shoulder arthroscopy prior to arthroplasty and (2) individuals with no documented history of arthroscopy prior to arthroplasty. These cohorts were propensity matched based on demographic and comorbidity factors. Univariate analysis was used to determine differences in revision rates, aseptic loosening, periprosthetic fracture, and infection between the two cohorts.

Results

Seven hundred and eighty-eight patients were successfully matched from the two cohorts. Revision surgery (3.4% vs. 1.4%, p  =  0.001) and aseptic loosening (2.2% vs. 0.8% p  =  0.021) were significantly more common in the arthroscopy cohort. Periprosthetic fracture and periprosthetic infection were not found to be significantly different between cohorts.

Discussion

Shoulder arthroscopy in the year prior to shoulder arthroplasty is associated with an increased risk of complications, including revision and aseptic loosening.